JP2025040605A - Substrate thickness measuring device, substrate bonding system, and substrate thickness measuring method - Google Patents

Abstract

To provide a substrate thickness measurement device, a substrate bonding system, and a substrate thickness measurement method capable of accurately measuring the thickness of a substrate.SOLUTION: In a pre-alignment unit PU, a deviation correction actuator 1300 corrects positional deviation of a substrate W relative to a stage 1100. A thickness calculation unit 1912 calculates the thickness of the substrate W along a circumferential direction on the basis of a measurement result obtained by measuring a distance to an upper surface Wa of the substrate W by a first light source head 1710 and a measurement result obtained by measuring a distance to a lower surface Wb of the substrate W by a second light source head 1720 while the substrate W rotates. The thickness calculation unit 1912 calculates the thickness of the substrate W along a transport direction A on the basis of the measurement result obtained by measuring the distance to the upper surface Wa of the substrate W by the first light source head 1710 and the measurement result obtained by measuring the distance to the lower surface Wb of the substrate W by the second light source head 1720 while the substrate W is being transported in the transport direction A.SELECTED DRAWING: Figure 6

Description

The present invention relates to a substrate thickness measuring device, a substrate bonding system, and a substrate thickness measuring method.

Conventionally, there is known a bonding apparatus that bonds a first substrate to a second substrate disposed opposite the first substrate. One such apparatus is, for example, a substrate bonding apparatus that includes a first member that holds the first substrate, a second member that holds the second substrate, and a moving actuator that moves the second member (see, for example, Patent Document 1).

Patent Document 1 describes a bonding device that includes an upper chuck that adsorbs an upper wafer, a lower chuck that adsorbs a lower wafer, and a lower chuck movement unit that moves the lower chuck. In the bonding device described in Patent Document 1, the alignment mark of the upper wafer is imaged by the lower imaging unit, and the alignment mark of the lower wafer is imaged by the upper imaging unit. Then, based on the two image data, the horizontal position of the lower chuck is adjusted so that the alignment mark of the upper wafer overlaps with the alignment mark of the lower wafer. In this way, the upper wafer and the lower wafer are aligned. The lower chuck is then moved upward to bond the upper wafer and the lower wafer.

JP 2020-53685 A

By the way, in a substrate bonding device, fine electrodes formed on the surfaces of two substrates are electrically connected to each other, so it is necessary to align the two substrates with high precision. In recent years, with the miniaturization of wiring patterns, there is a demand for alignment precision of the order of several hundred to several tens of nanometers.

Here, when bonding two substrates together, the two substrates are aligned horizontally and then one substrate is moved vertically relative to the other substrate to bond the two substrates together. However, the vertical movement reduces the horizontal positional accuracy of the two substrates. One way to improve this is to shorten the vertical movement distance after aligning the two substrates. In this case, the vertical movement distance after aligning the two substrates needs to be set to, for example, several μm to several tens of μm. In other words, the distance between the two substrates when aligning them needs to be set to, for example, several μm to several tens of μm.

Normally, when two substrates are brought closer together, for example, the second member is brought closer to the first member so that the distance between the first member holding one substrate and the second member holding the other substrate is equal to the sum of the target distance between the two substrates and the thickness of the two substrates. However, the thickness of the substrate varies not only between substrates but also within a single substrate. For this reason, when the two substrates are brought closer together so that the distance between them is several μm to several tens of μm, there is a risk that the two substrates will come into contact with each other due to the variation in substrate thickness. To avoid this, it is necessary to measure the thickness of the substrate with high accuracy.

The present invention has been made in consideration of the above problems, and its purpose is to provide a substrate thickness measurement device, a substrate bonding system, and a substrate thickness measurement method that are capable of measuring the thickness of a substrate with high accuracy.

A substrate thickness measuring device according to a first aspect of the present invention includes a stage, a detection sensor, a deviation calculation unit, a deviation correction actuator, a rotation actuator, a first distance measurement sensor, a second distance measurement sensor, and a thickness calculation unit. The stage holds the substrate horizontally. The detection sensor detects the position of the substrate held on the stage. The deviation calculation unit calculates the amount of positional deviation of the substrate relative to the stage based on the detection result of the detection sensor. The deviation correction actuator corrects the positional deviation of the substrate relative to the stage. The rotation actuator rotates the stage while holding the substrate. The first distance measurement sensor is disposed above the substrate held on the stage and measures the distance to the upper surface of the substrate. The second distance measurement sensor is disposed below the substrate held on the stage and measures the distance to the lower surface of the substrate. The thickness calculation unit calculates the thickness of the substrate based on the measurement result of the first distance measurement sensor and the measurement result of the second distance measurement sensor. The misalignment correction actuator corrects the misalignment of the substrate relative to the stage by moving one of the substrate and the stage in a horizontal direction relative to the other of the substrate and the stage based on the calculation result of the misalignment calculation unit. The thickness calculation unit calculates the thickness of the substrate along the circumferential direction based on the measurement result of the first distance measurement sensor measuring the distance to the top surface of the substrate and the measurement result of the second distance measurement sensor measuring the distance to the bottom surface of the substrate while the rotation actuator rotates the stage holding the substrate whose misalignment has been corrected. The thickness calculation unit calculates the thickness of the substrate along the transport direction based on the measurement result of the first distance measurement sensor measuring the distance to the top surface of the substrate and the measurement result of the second distance measurement sensor measuring the distance to the bottom surface of the substrate while the transport actuator transports the substrate whose misalignment has been corrected in a transport direction that is horizontal to the stage.

In one embodiment, the transport actuator transports the substrate in the transport direction such that the first distance measuring sensor and the second distance measuring sensor measure the distance along a straight line passing through the center of the substrate. The thickness calculation unit calculates the thickness of the substrate along the transport direction based on a measurement result of the first distance measuring sensor measuring the distance to the top surface of the substrate along a straight line passing through the center of the substrate and a measurement result of the second distance measuring sensor measuring the distance to the bottom surface of the substrate along a straight line passing through the center of the substrate while the transport actuator transports the substrate in the transport direction.

In one embodiment, the misalignment correction actuator has a holder, a holder movement actuator, and a horizontal movement actuator. The holder transfers the substrate between the stage by moving up and down relative to the stage. The holder movement actuator moves the holder up and down relative to the stage. The horizontal movement actuator moves one of the holder and the stage horizontally relative to the other of the holder and the stage. In a state in which the holder holds the substrate by the holder movement actuator moving the holder upward relative to the stage, the horizontal movement actuator corrects the positional misalignment of the substrate relative to the stage by moving one of the holder and the stage horizontally relative to the other of the holder and the stage based on the calculation result of the misalignment calculation unit.

In one embodiment, the substrate thickness measuring device further includes a housing that houses the first distance measuring sensor and the second distance measuring sensor and to which the first distance measuring sensor and the second distance measuring sensor are fixed.

In one embodiment, the transport actuator is disposed outside the housing. The housing has a window through which the transport arm of the transport actuator passes.

In one embodiment, the first distance measuring sensor includes a first optical head that emits a first emitted light toward the upper surface of the substrate. The second distance measuring sensor includes a second optical head that emits a second emitted light toward the lower surface of the substrate.

In one embodiment, the optical axis of the second emitted light from the second optical head is coaxial with the optical axis of the first emitted light from the first optical head.

In one embodiment, the first optical head has a first light-emitting element that emits the first emitted light, and a first light-receiving element that receives light of the first emitted light emitted from the first light-emitting element that is reflected by the upper surface of the substrate. The second optical head has a second light-emitting element that emits the second emitted light, and a second light-receiving element that receives light of the second emitted light emitted from the second light-emitting element that is reflected by the lower surface of the substrate.

A substrate bonding system according to a second aspect of the present invention includes the above-mentioned substrate thickness measuring device and a substrate bonding device that bonds a first substrate and a second substrate whose thicknesses have been measured by the substrate thickness measuring device.

In one embodiment, the substrate bonding apparatus includes a first substrate holder, a second substrate holder, a substrate holder actuator, and an acquisition unit. The first substrate holder holds the first substrate horizontally. The second substrate holder holds the second substrate horizontally. The substrate holder actuator moves one of the first substrate holder and the second substrate holder in the vertical direction relative to the other of the first substrate holder and the second substrate holder. The acquisition unit acquires the calculation result of the thickness calculation unit of the substrate thickness measuring apparatus. The substrate holder actuator moves one of the first substrate holder and the second substrate holder relative to the other of the first substrate holder and the second substrate holder based on the calculation result of the thickness calculation unit so that the distance between the first substrate and the second substrate is within a predetermined range.

The substrate thickness measurement method according to the third aspect of the present invention includes the steps of: detecting the position of a substrate held horizontally on a stage; calculating the amount of positional deviation of the substrate relative to the stage based on the detection result of the position of the substrate; correcting the positional deviation of the substrate relative to the stage by moving one of the substrate and the stage in a horizontal direction relative to the other of the substrate and the stage based on the calculation result of the amount of positional deviation; calculating the thickness of the substrate along the circumferential direction based on the measurement result of the first distance measuring sensor measuring the distance to the upper surface of the substrate and the measurement result of the second distance measuring sensor measuring the distance to the lower surface of the substrate while the stage holding the substrate whose positional deviation has been corrected rotates; and calculating the thickness of the substrate along the transport direction based on the measurement result of the first distance measuring sensor measuring the distance to the upper surface of the substrate and the measurement result of the second distance measuring sensor measuring the distance to the lower surface of the substrate while the substrate whose positional deviation has been corrected is transported in a transport direction that is horizontal to the stage.

The present invention provides a substrate thickness measuring device, a substrate bonding system, and a substrate thickness measuring method that can measure the thickness of a substrate with high accuracy.

1 is a plan view showing a schematic configuration of a substrate bonding system according to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a substrate bonding system. 2 is a cross-sectional view that illustrates a schematic diagram of a transport unit, a transport robot, a pre-alignment unit, and a bonding unit. FIG. FIG. 2 is a perspective view showing a structure of a pre-alignment unit. FIG. 4 is a perspective view showing the structure of a holder moving actuator. FIG. 2 is a block diagram showing a configuration of a pre-alignment unit. 5A and 5B are schematic diagrams for explaining a method of detecting the position of a substrate by a detection sensor. FIG. 2 is a plan view showing a structure of a substrate. 1A and 1B are schematic diagrams for explaining a method for measuring the thickness of a substrate using a distance measuring device. 5A and 5B are schematic diagrams for explaining a method for measuring the distance to a substrate in a circumferential direction by a distance measuring device. 5A and 5B are schematic diagrams for explaining a method for measuring the distance to a substrate along the transport direction by a distance measuring device. 10 is a flowchart showing an example of the operation of a pre-alignment unit and a transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. 11A and 11B are schematic diagrams for explaining an example of the operation of the pre-alignment unit and the transport unit. FIG. 2 is a perspective view showing a schematic structure of a joint unit. 13 is a schematic diagram showing the structure around the second substrate holder of the joining unit as viewed from the X direction. FIG. 13 is a schematic diagram showing the structure around the second substrate holder of the joining unit as viewed from the Y direction. FIG. 1 is a schematic diagram showing the structure around the support base from below. FIG. FIG. 2 is a perspective view showing a structure of the joint unit from below. 10 is a flowchart showing a method for bonding a joint unit. FIG. 2 is a side view that illustrates a state in which a first substrate and a second substrate are disposed opposite each other.

Below, an embodiment of a substrate bonding system equipped with a substrate thickness measuring device according to the present invention will be described with reference to the drawings. Note that in the drawings, the same or corresponding parts are given the same reference symbols and the description will not be repeated. In this specification, to facilitate understanding of the invention, mutually orthogonal X-axis, Y-axis, and Z-axis may be described. In this embodiment, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

The substrate bonding system 1 according to this embodiment will be described with reference to Figures 1 to 30. First, the overall configuration of the substrate bonding system 1 will be described with reference to Figure 1. Figure 1 is a plan view showing the schematic configuration of the substrate bonding system 1 according to one embodiment of the present invention.

As shown in FIG. 1, the substrate bonding system 1 stacks and bonds a first substrate W1 and a second substrate W2. In this embodiment, the substrate bonding system 1 performs, for example, an activation process, a cleaning process, and a bonding process on the first substrate W1 and the second substrate W2.

The first substrate W1 and the second substrate W2 include, for example, a semiconductor substrate. The first substrate W1 and the second substrate W2 include, for example, a semiconductor wafer. The first substrate W1 and the second substrate W2 are, for example, substantially disk-shaped.

The first substrate W1 has a plurality (e.g., several tens to several hundreds) of first semiconductor chips (not shown). Each first semiconductor chip constitutes an integrated circuit such as a CPU and/or DRAM. Each first semiconductor chip has, for example, a semiconductor element layer (not shown) in which a plurality of semiconductor elements such as transistors are formed, and a plurality of electrodes (not shown). The electrodes are formed of a metal material such as copper, gold, or aluminum. In this embodiment, the electrodes are formed of, for example, copper.

The second substrate W2 has a plurality (e.g., several tens to several hundreds) of second semiconductor chips (not shown). Each second semiconductor chip constitutes an integrated circuit such as a CPU and/or DRAM. Each second semiconductor chip has, for example, a semiconductor element layer (not shown) in which a plurality of semiconductor elements such as transistors are formed, and a plurality of electrodes (not shown). The electrodes are formed of a metal material such as copper, gold, or aluminum. In this embodiment, the electrodes are formed of, for example, copper.

The electrodes of the first substrate W1 and the electrodes of the second substrate W2 are joined and electrically connected. Specifically, the number of electrodes of the first substrate W1 is the same as the number of electrodes of the second substrate W2. The electrodes of the second substrate W2 are disposed at positions corresponding to the electrodes of the first substrate W1.

The electrodes of the first substrate W1 and the second substrate W2 are formed, for example, as bumps and/or electrode pads. From the viewpoint of ease of joining, it is preferable that at least one of the electrodes of the first substrate W1 and the electrodes of the second substrate W2 is formed as a bump. In this embodiment, both the electrodes of the first substrate W1 and the electrodes of the second substrate W2 are formed as bumps.

The substrate bonding system 1 includes a transport path CP, a first load port LP1, a second load port LP2, a third load port LP3, an activation unit AU, a cleaning unit CU, a pre-alignment unit PU, a transport unit TU, a bonding unit JU, a center robot CR, a transport robot TR, and a control device 90. The pre-alignment unit PU is an example of a "substrate thickness measuring device" of the present invention. The bonding unit JU is an example of a "substrate bonding device" of the present invention. The transport robot TR is an example of a "transport actuator" of the present invention.

The transport path CP transports the first substrate W1 and the second substrate W2. The transport path CP has, for example, a linear shape. The center robot CR, the first load port LP1, the second load port LP2, the third load port LP3, the activation unit AU, the cleaning unit CU, the pre-alignment unit PU, the transport unit TU, and the bonding unit JU are arranged to face the transport path CP.

The center robot CR holds and transports the first substrate W1 and the second substrate W2. The center robot CR moves within the transport path CP. The center robot CR transports the first substrate W1 and the second substrate W2 between the first load port LP1, the second load port LP2, the third load port LP3, the activation unit AU, the cleaning unit CU, and the transport unit TU.

The first load port LP1 accommodates multiple (e.g., 25) first substrates W1. Specifically, the multiple first substrates W1 are accommodated in a stacked state in a FOUP (also called a carriage) (not shown). The FOUP accommodating the first substrates W1 is accommodated in the first load port LP1.

The second load port LP2 accommodates multiple (e.g., 25) second substrates W2. Specifically, the multiple second substrates W2 are accommodated in a stacked state in a FOUP (not shown). The FOUP accommodating the second substrates W2 is accommodated in the second load port LP2.

The third load port LP3 accommodates multiple (e.g., 25) laminated substrates WL. Specifically, the multiple laminated substrates WL are accommodated in a hoop (not shown) in a stacked state. The hoop that accommodates the laminated substrates WL is accommodated in the third load port LP3.

The laminated substrate WL is a substrate in which a first substrate W1 and a second substrate W2 are laminated and bonded together. In this embodiment, the laminated substrate WL is formed by laminating and bonding a first substrate W1 and a second substrate W2.

The activation unit AU activates the surfaces of the first substrate W1 and the second substrate W2. The activation unit AU activates at least the surfaces of the electrodes of the first substrate W1 and the second substrate W2. Specifically, the activation unit AU performs plasma processing on the first substrate W1 and the second substrate W2. The type of gas used in the plasma processing is not particularly limited, but is, for example, oxygen or nitrogen.

The activation unit AU has, for example, a high-frequency power supply and a pair of electrodes to which a high-frequency voltage is applied. By applying a high-frequency voltage between the pair of electrodes, the processing gas is turned into plasma. For example, when oxygen gas is used as the processing gas, the oxygen gas is turned into plasma and becomes oxygen ions. When the oxygen ions are irradiated onto the surface of the first substrate W1 or the second substrate W2, dangling bonds are generated on the surface of the electrodes. In other words, the surface of the electrodes is activated.

The cleaning unit CU cleans the first substrate W1 and the second substrate W2. The cleaning unit CU supplies a cleaning liquid to the first substrate W1 and the second substrate W2. Specifically, the cleaning unit CU has a cleaning nozzle (not shown) that ejects the cleaning liquid. Examples of the cleaning liquid include deionized water (DIW), carbonated water, electrolytic ionized water, ozone water, ammonia water, hydrochloric acid water with a diluted concentration (e.g., about 10 ppm to 100 ppm), or reduced water (hydrogen water). In this embodiment, the cleaning liquid is pure water such as DIW.

By cleaning the first substrate W1 and the second substrate W2 using the cleaning unit CU, the electrodes of the first substrate W1 and the second substrate W2 are cleaned. At this time, hydroxyl groups are formed on the surfaces of the electrodes.

The transport unit TU is arranged to face the transport path CP, the pre-alignment unit PU, and the joining unit JU. The transport unit TU houses the transport robot TR.

The transport robot TR holds and transports the first substrate W1 and the second substrate W2. The transport robot TR delivers the first substrate W1 and the second substrate W2 between the center robot CR, the pre-alignment unit PU, and the bonding unit JU. The transport robot TR is fixed to the floor of the transport unit TU and does not move within the transport unit TU. For this reason, the transport accuracy of the transport robot TR is higher than that of the center robot CR, which moves within the transport path CP.

The pre-alignment unit PU aligns the first substrate W1 and the second substrate W2 one by one. In this embodiment, the pre-alignment unit PU aligns the first substrate W1 and the second substrate W2 one by one before alignment in the joining unit JU. Note that alignment by the pre-alignment unit PU may be referred to as pre-alignment.

In addition, in this embodiment, the pre-alignment unit PU functions as a thickness measuring device that measures the thicknesses of the first substrate W1 and the second substrate W2. The detailed structure of the pre-alignment unit PU will be described later.

The joining unit JU joins the first substrate W1 and the second substrate W2. Specifically, the joining unit JU performs highly accurate alignment on the pre-aligned first substrate W1 and second substrate W2 transported from the pre-alignment unit PU. The joining unit JU then joins the electrodes of the first substrate W1 and the electrodes of the second substrate W2. The detailed structure of the joining unit JU will be described later.

Figure 2 is a block diagram showing the configuration of the substrate bonding system 1. As shown in Figure 2, the control device 90 controls various operations of the substrate bonding system 1. The control device 90 includes a control unit 91 and a memory unit 93. The control unit 91 has a processor. The control unit 91 has, for example, a central processing unit (CPU). Alternatively, the control unit 91 may have a general-purpose computer.

The memory unit 93 stores data and computer programs. The data specifies, for example, the processing content and processing procedures for joining.

The storage unit 93 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and/or a hard disk drive. The storage unit 93 may include removable media. The control unit 91 executes a computer program stored in the storage unit 93 to perform the joining operation.

The control unit 91 controls the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, and bonding unit JU. Specifically, the control unit 91 controls the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, and bonding unit JU by sending control signals to the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, and bonding unit JU.

More specifically, the control unit 91 controls the center robot CR to transfer the substrate W by the center robot CR. The substrate W includes a first substrate W1 and a second substrate W2. In the following description, when there is no need to distinguish between the first substrate W1 and the second substrate W2, the first substrate W1 or the second substrate W2 may be referred to as the substrate W. The center robot CR, for example, receives an unprocessed substrate W and transports the substrate W to the activation unit AU. The center robot CR also receives an activated substrate W from the activation unit AU and transports it to the cleaning unit CU. The center robot CR also receives a cleaned substrate W from the cleaning unit CU and transports it to the bonding unit JU.

The control unit 91 controls the activation unit AU to control the plasma processing on the substrate W. For example, the control unit 91 controls the output voltage and processing time of the activation unit AU.

The control unit 91 controls the cleaning unit CU to control the cleaning process for the substrate W. For example, the control unit 91 opens or closes a valve (not shown) of the cleaning unit CU to supply or stop the supply of cleaning liquid to the substrate W.

The control unit 91 controls the transport robot TR to transfer the substrate W by the transport robot TR. For example, the transport robot TR receives the substrate W from the center robot CR and passes the substrate W to the pre-alignment unit PU. The transport robot TR also receives the substrate W from the pre-alignment unit PU and passes the substrate W to the joining unit JU. The transport robot TR also receives the stacked substrate WL from the joining unit JU and passes the stacked substrate WL to the center robot CR.

The control unit 91 controls the pre-alignment unit PU. Specifically, the control unit 91 controls the pre-alignment unit PU to pre-align the substrate W. The control unit 91 also controls the pre-alignment unit PU to measure the thickness of the pre-aligned substrate W.

The control unit 91 controls the joining unit JU. Specifically, the control unit 91 controls the joining unit JU to bond the first substrate W1 and the second substrate W2 together.

Next, the transport unit TU, the transport robot TR, the pre-alignment unit PU, and the joining unit JU will be described with reference to FIG. 3. FIG. 3 is a cross-sectional view that shows a schematic diagram of the transport unit TU, the transport robot TR, the pre-alignment unit PU, and the joining unit JU.

As shown in FIG. 3, the transport unit TU has a transport housing 3010 and a blower unit 3020. The transport housing 3010 is composed of multiple (four in this example) side walls 3011, a floor 3012, and a ceiling 3013. The transport housing 3010 separates the inside and outside of the transport unit TU.

The sidewall 3011 has a sidewall 3011a arranged adjacent to the pre-alignment unit PU, and a sidewall 3011b arranged adjacent to the joining unit JU. An opening window 3011c is formed in the sidewall 3011a, penetrating the sidewall 3011a in the thickness direction. An opening window 3011d is formed in the sidewall 3011b, penetrating the sidewall 3011b in the thickness direction. The opening windows 3011c and 3011d are formed to a size that allows the substrate W to pass through.

The blower unit 3020 is disposed on or above the transport housing 3010. For example, the blower unit 3020 is disposed on the ceiling 3013 of the transport housing 3010. The blower unit 3020 sends air into the transport housing 3010. The blower unit 3020 includes, for example, a fan filter unit (FFU). A downflow is formed in the transport housing 3010 by the blower unit 3020 and an exhaust device (not shown).

A transport robot TR is disposed within the transport housing 3010. The transport robot TR is fixed to the floor 3012 of the transport housing 3010. The transport robot TR has a transport arm 3510 and a transport drive unit 3520. The transport arm 3510 has an upper surface 3510a that supports the lower surface of the substrate W. The transport arm 3510 supports the substrate W and transports the substrate W in the horizontal direction.

The transport drive unit 3520 moves the transport arm 3510 in the horizontal direction. The transport drive unit 3520 moves the transport arm 3510 linearly in the horizontal direction. In this embodiment, the transport drive unit 3520 rotates the transport arm 3510 around a central axis (not shown) that extends in the vertical direction. The transport drive unit 3520 has, for example, a stepping motor and a rack and pinion that converts the rotational drive of the stepping motor into linear drive in the horizontal direction.

The transport arm 3510 is formed to a size that allows it to pass through the opening windows 3011c and 3011d. The transport arm 3510 transfers the substrate W between the pre-alignment unit PU through the opening window 3011c. The transport arm 3510 also transfers the substrate W between the bonding unit JU through the opening window 3011d.

Although not shown, the side wall 3011 facing the transport path CP also has an opening through which the substrate W can pass, and the transport arm 3510 transfers the substrate W to and from the center robot CR through the opening, not shown.

The pre-alignment unit PU has an alignment housing 1010 and a blower unit 1020. The alignment housing 1010 is an example of the "housing" of the present invention. The alignment housing 1010 has multiple (four in this case) side walls 1011, a floor 1012, and a ceiling 1013. The alignment housing 1010 separates the inside and outside of the pre-alignment unit PU.

The side wall 1011 has a side wall 1011a disposed adjacent to the transport unit TU. The side wall 1011a has an opening window 1011c formed therein, which penetrates the side wall 1011a in the thickness direction. The opening window 1011c is an example of a "window" in the present invention. The opening window 1011c is formed to a size that allows the substrate W to pass through.

Note that the side wall 1011a and the side wall 3011a may be provided separately, or may be a single side wall. In other words, the pre-alignment unit PU and the transport unit TU may share a single side wall. In the following explanation, for simplicity, an example will be described in which the side wall 1011a of the pre-alignment unit PU is shared as the side wall 3011a of the transport unit TU.

The blower unit 1020 is disposed on or above the alignment housing 1010. For example, the blower unit 1020 is disposed on the ceiling 1013 of the alignment housing 1010. The blower unit 1020 sends air into the alignment housing 1010. The blower unit 1020 includes, for example, a fan filter unit. A downflow is formed in the alignment housing 1010 by the blower unit 1020 and an exhaust device (not shown).

An alignment device 1001 is disposed inside the alignment housing 1010. The alignment device 1001 is fixed to the floor 1012 of the alignment housing 1010. The alignment device 1001 transfers the substrate W to and from the transport robot TR.

The joining unit JU has a joining housing 4010 and a blower unit 4020. The joining housing 4010 has multiple (four in this example) side walls 4011, a floor 4012, and a ceiling 4013. The joining housing 4010 separates the inside and outside of the joining unit JU.

The side wall 4011 has a side wall 4011a disposed adjacent to the transport unit TU. The side wall 4011a has an opening window 4011c formed therein, which penetrates the side wall 4011a in the thickness direction. The opening window 4011c is formed to a size that allows the substrate W to pass through.

The side wall 4011a and the side wall 3011a may be provided separately, or may be a single side wall. In other words, the joining unit JU and the transport unit TU may share a single side wall. In the following explanation, for simplicity, an example will be described in which the side wall 4011a of the joining unit JU is shared as the side wall 3011a of the transport unit TU.

The blower unit 4020 is disposed on or above the joined housing 4010. For example, the blower unit 4020 is disposed on the ceiling 4013 of the joined housing 4010. The blower unit 4020 sends air into the joined housing 4010. The blower unit 4020 includes, for example, a fan filter unit. A downflow is formed in the joined housing 4010 by the blower unit 4020 and an exhaust device (not shown).

Next, the detailed structure of the pre-alignment unit PU will be described with reference to Figure 4. Figure 4 is a perspective view showing the structure of the pre-alignment unit PU.

As shown in FIG. 4, the pre-alignment unit PU includes an alignment device 1001 and an alignment housing 1010. The alignment device 1001 includes a stage 1100, a rotation actuator 1200, a misalignment correction actuator 1300, a detection sensor 1600, a distance measurement device 1700, and a control device 1900 (see FIG. 6). The stage 1100, the rotation actuator 1200, the misalignment correction actuator 1300, the detection sensor 1600, the distance measurement device 1700, and the control device 1900 are housed in the alignment housing 1010. The detection sensor 1600 is an example of the "detection sensor" of the present invention.

The alignment housing 1010 further includes a plurality of (here, four) housing frames 1030. The housing frames 1030 are, for example, metal frames that are L-shaped in cross section. The housing frames 1030 are, for example, arranged to extend in the vertical direction at the four corners of the pre-alignment unit PU. Specifically, the housing frames 1030 are arranged at the boundaries between adjacent side walls 1011, and the side walls 1011 are fixed. A housing frame (not shown) that extends in the horizontal direction may be further provided to connect the vertically extending housing frames 1030 to each other. In FIG. 4, the ceiling 1013 of the alignment housing 1010 and some of the side walls 1011 are shown by two-dot chain lines for ease of understanding.

The stage 1100 holds the substrate W horizontally. In this embodiment, the stage 1100 has a support plate 1110 and a number of support pins 1120. The support plate 1110 is made of, for example, sheet metal. The support plate 1110 is arranged horizontally. The shape of the support plate 1110 is not particularly limited, but is, for example, rectangular.

Multiple (four in this embodiment) support pins 1120 are attached to the four corners of the support plate 1110. The support pins 1120 are fixed to the support plate 1110 so as to protrude upward from the support plate 1110. The tips (upper ends) of the support pins 1120 support the lower surface of the substrate W. Note that the support pins 1120 may adsorb the lower surface of the substrate W, but in this embodiment, they do not adsorb the lower surface of the substrate W.

The stage 1100 also has an outer shape that is smaller than the substrate W. Specifically, when the stage 1100 holds the substrate W, the entire stage 1100 is positioned radially inward from the periphery of the substrate W in a plan view. In this embodiment, the stage 1100 does not move in the vertical direction. In other words, the height position of the stage 1100 is constant.

The rotary actuator 1200 rotatably supports the stage 1100. Specifically, the rotary actuator 1200 has a rotary shaft 1210, a main body 1220, and a motor 1230. The rotary shaft 1210 is arranged so that a rotation axis L1210 extends in the vertical direction. The rotation axis L1210 of the rotary actuator 1200 coincides with the central axis (not shown) of the stage 1100.

The upper end of the rotating shaft 1210 is fixed to the lower surface of the stage 1100. The lower end of the rotating shaft 1210 is inserted inside the main body 1220.

The main body 1220 has, for example, a substantially rectangular parallelepiped shape. A motor 1230 is attached to the side of the main body 1220 in the Y direction.

The motor 1230 is not particularly limited, but may be, for example, a stepping motor. The motor 1230 is arranged such that the rotation axis (not shown) extends, for example, in the horizontal direction (here, the Y direction).

A transmission member (not shown) is provided inside the main body 1220 to transmit the driving force of the motor 1230 to the rotating shaft 1210. In this embodiment, the transmission member converts the rotational driving force of the motor 1230 around a rotation axis extending in the horizontal direction into a rotational driving force around a rotation axis L1210 extending in the vertical direction. The transmission member has, for example, a helical gear or a bevel gear.

When the motor 1230 of the rotary actuator 1200 is driven (rotated), the rotational driving force of the motor 1230 is transmitted to the rotary shaft 1210 via a transmission member (not shown). As a result, the rotary shaft 1210 rotates about a rotation axis L1210 extending in the vertical direction, and the stage 1100 rotates about the rotation axis L1210. Therefore, the substrate W held by the stage 1100 also rotates about the rotation axis L1210.

The misalignment correction actuator 1300 corrects the positional misalignment of the substrate W relative to the stage 1100. In this embodiment, the misalignment correction actuator 1300 corrects the horizontal positional misalignment of the center of the substrate W relative to the center of the stage 1100.

Specifically, the misalignment correction actuator 1300 has a holder 1310, a holder movement actuator 1330, a first horizontal movement actuator 1400, and a second horizontal movement actuator 1500. The first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 are examples of the "horizontal movement actuator" of the present invention.

The holder 1310 holds the substrate W horizontally. The holder 1310 can transfer the substrate W to and from the stage 1100. The holder 1310 has a support ring 1311 and a number of support pins 1312. The support ring 1311 is made of, for example, sheet metal. The support ring 1311 is arranged horizontally. The shape of the support ring 1311 is not particularly limited, but is, for example, a circular ring shape.

Multiple (eight in this embodiment) support pins 1312 are attached to the support ring 1311, two at a time, at angular intervals of approximately 90 degrees around the central axis (not shown) of the support ring 1311. The support pins 1312 are fixed to the support ring 1311 so as to protrude upward from the support ring 1311. The tips (upper ends) of the support pins 1312 support the lower surface of the substrate W. Note that the support pins 1312 may adsorb the lower surface of the substrate W, but in this embodiment, they do not adsorb the lower surface of the substrate W.

The support ring 1311 has an outer peripheral edge 1311a and an inner peripheral edge 1311b. The outer peripheral edge 1311a forms the outer shape of the support ring 1311. The inner peripheral edge 1311b forms a through hole 1311c of the support ring 1311.

The through hole 1311c of the support ring 1311 is formed to a size that allows the support plate 1110 to pass through. Specifically, in a plan view, the entire support plate 1110 is positioned radially inward from the inner peripheral edge 1311b of the support ring 1311.

The holder 1310 also has an outer shape that is smaller than the substrate W. Specifically, when the holder 1310 holds the substrate W, the entire holder 1310 is positioned radially inward from the periphery of the substrate W in a planar view. In other words, when the holder 1310 holds the substrate W, the outer periphery 1311a of the support ring 1311 is positioned radially inward from the periphery of the substrate W in a planar view.

The holder movement actuator 1330 supports the holder 1310 and moves the holder 1310 in the vertical direction relative to the stage 1100. Note that in FIG. 4, for ease of understanding, only a portion of the holder movement actuator 1330 is depicted. The structure of the holder movement actuator 1330 will be described later.

The first horizontal movement actuator 1400 moves the holder 1310, for example, in the Y direction. In this embodiment, the first horizontal movement actuator 1400 moves the rotation actuator 1200 in the Y direction, thereby moving the holder 1310 in the Y direction. Specifically, the first horizontal movement actuator 1400 has a main body 1410, a motor 1420, and a moving stage 1430.

The main body 1410 has, for example, a substantially rectangular parallelepiped shape. The main body 1410 has an elongated shape extending in the Y direction. A motor 1420 is attached to the end face of the main body 1410 in the Y direction. The motor 1420 is not particularly limited, but includes, for example, a stepping motor. The motor 1420 is arranged so that the axis of rotation (not shown) extends in the Y direction.

A recess 1411 is formed on the side surface of the main body 1410 in the X direction, into which a part of the movable stage 1430 is inserted. The recess 1411 extends in the Y direction. A transmission member (not shown) that transmits the driving force of the motor 1420 to the movable stage 1430 is provided inside the main body 1410. In this embodiment, the transmission member converts the rotational driving force of the motor 1420 around a rotation axis extending in the Y direction into a driving force along the Y direction. For example, the transmission member has a worm gear, and the movable stage 1430 has rack teeth that engage with the worm gear.

The moving platform 1430 is made of, for example, metal. The moving platform 1430 has, for example, a U-shape in cross section. The lower part of the moving platform 1430 is inserted into the recess 1411. The moving platform 1430 extends upward from the recess 1411 and protrudes above the upper surface of the main body 1410. The rotation actuator 1200 is placed and fixed on the upper end of the moving platform 1430.

When the motor 1420 is driven (rotated), the rotational driving force of the motor 1420 is transmitted to the moving stage 1430 via a transmission member (not shown). As a result, the moving stage 1430 moves in the Y direction along the recess 1411, and the rotation actuator 1200 fixed to the moving stage 1430 moves in the Y direction. Therefore, the stage 1100 fixed to the rotation actuator 1200 moves in the Y direction.

The second horizontal movement actuator 1500 is fixed to the floor 1012. The second horizontal movement actuator 1500 moves the holder 1310, for example, in the X direction. In this embodiment, the second horizontal movement actuator 1500 moves the first horizontal movement actuator 1400 and the rotation actuator 1200 in the X direction, thereby moving the holder 1310 in the X direction. Specifically, the second horizontal movement actuator 1500 has a main body 1510, a motor 1520, and a moving stage 1530.

The main body 1510 has, for example, a substantially rectangular parallelepiped shape. The main body 1510 has an elongated shape extending in the X direction. A motor 1520 is attached to the end face of the main body 1510 in the X direction. The motor 1520 is not particularly limited, but includes, for example, a stepping motor. The motor 1520 is arranged so that the rotation axis (not shown) extends in the X direction.

A recess 1511 is formed on the Y-direction side of the main body 1510, into which a part of the movable stage 1530 is inserted. The recess 1511 extends in the X-direction. A transmission member (not shown) that transmits the driving force of the motor 1520 to the movable stage 1530 is provided inside the main body 1510. In this embodiment, the transmission member converts the rotational driving force of the motor 1520 around a rotation axis extending in the X-direction into a driving force along the X-direction. For example, the transmission member has a worm gear, and the movable stage 1530 has rack teeth that engage with the worm gear.

The moving platform 1530 is made of, for example, metal. The moving platform 1530 has, for example, a U-shape in cross section. The lower part of the moving platform 1530 is inserted into the recess 1511. The moving platform 1530 extends upward from the recess 1511 and protrudes above the upper surface of the main body 1510. The main body 1410 of the first horizontal movement actuator 1400 is placed and fixed on the upper end of the moving platform 1530.

When the motor 1520 is driven (rotated), the rotational driving force of the motor 1520 is transmitted to the moving stage 1530 via a transmission member (not shown). As a result, the moving stage 1530 moves in the X direction along the recess 1511, and the first horizontal movement actuator 1400 fixed to the moving stage 1530 moves in the X direction. Therefore, the rotation actuator 1200 fixed to the first horizontal movement actuator 1400 moves in the X direction, and the stage 1100 fixed to the rotation actuator 1200 moves in the X direction.

The method for correcting the positional misalignment of the substrate W relative to the stage 1100 using the misalignment correction actuator 1300 will be described later.

The detection sensor 1600 detects the position of the substrate W held on the stage 1100. Specifically, the detection sensor 1600 has a light emitting head 1610, a light receiving head 1620, and a support frame 1630.

The support frame 1630 is, for example, a metal frame that is L-shaped in cross section. The support frame 1630 is disposed radially outward from the support ring 1311. The support frame 1630 is fixed to the floor 1012 so as to extend in the vertical direction.

A light-emitting head 1610 is fixed to the upper part of the support frame 1630, and a light-receiving head 1620 is fixed to the lower part of the support frame 1630. The light-emitting head 1610 is positioned above the edge of the substrate W, and the light-receiving head 1620 is positioned below the edge of the substrate W.

The light emission head 1610 emits a strip of light having a predetermined width (e.g., a width of 5 mm to 20 mm) downward. The light emission head 1610 is positioned so that a portion of the strip of light irradiates the top surface of the substrate W, and the remainder of the strip of light passes along the side of the substrate W.

The light receiving head 1620 receives the light that is emitted from the light emitting head 1610 and passes through the side of the substrate W.

The method for detecting the position of the substrate W using the detection sensor 1600 will be described later.

The distance measurement device 1700 measures the distance to the substrate W held on the stage 1100. Specifically, the distance measurement device 1700 has a first optical head 1710, a second optical head 1720, and a fixed member 1730. The first optical head 1710 is an example of a "first distance measurement sensor" in the present invention. The second optical head 1720 is an example of a "second distance measurement sensor" in the present invention.

The fixing member 1730 is made of, for example, sheet metal. The fixing member 1730 holds, for example, the first optical head 1710 in a predetermined position. Note that the distance measurement device 1700 may further include a fixing member that holds the second optical head 1720 in a predetermined position.

In this embodiment, the fixing member 1730 has a first plate 1731 and a second plate 1732. The first plate 1731 extends in the Y direction and is fixed across two housing frames 1030 adjacent to the transport unit TU. The second plate 1732 is fixed to the first plate 1731 so as to extend from the center of the first plate 1731 in the Y direction toward the center of the alignment housing 1010. The first optical head 1710 is fixed to the underside of the tip of the second plate 1732.

The first optical head 1710 is positioned above the substrate W held on the stage 1100. The first optical head 1710 emits a first emitted light toward the upper surface of the substrate W. The first optical head 1710 also measures the distance to the upper surface of the substrate W held on the stage 1100 by receiving the light of the emitted first emitted light that is reflected by the upper surface of the substrate W.

The second optical head 1720 is positioned below the substrate W held on the stage 1100. The second optical head 1720 emits a second emitted light toward the bottom surface of the substrate W. The second optical head 1720 also measures the distance to the bottom surface of the substrate W held on the stage 1100 by receiving the light of the emitted second emitted light that is reflected by the bottom surface of the substrate W.

The method for measuring the thickness of the substrate W using the distance measuring device 1700 will be described later.

In addition, in this embodiment, all of the movable or operable components (here, the stage 1100, the rotation actuator 1200, and the misalignment correction actuator 1300) are located below the substrate W. This makes it possible to prevent particles generated by the movement or operation of the components from adhering to the substrate W.

Next, the holder movement actuator 1330 will be described with reference to FIG. 5. FIG. 5 is a perspective view showing the structure of the holder movement actuator 1330. As shown in FIG. 5, the holder movement actuator 1330 has a support frame 1331, a fixed piece 1332, and a drive unit 1333.

The support frame 1331 is, for example, a metal frame that is L-shaped in cross section. The support frame 1331 has, for example, two frames 1331a and 1331b, and is formed in a U-shape in plan view. The two frames 1331a and 1331b are arranged to extend, for example, in the horizontal direction. The two frames 1331a extend in the Y direction and are arranged parallel to each other and spaced apart in the X direction. The frame 1331b extends in the X direction and connects the ends of the two frames 1331a.

The support frame 1331 is fixed to the underside of the support ring 1311 and supports the support ring 1311 from below. This prevents the support ring 1311 from bending due to its own weight and/or the weight of the substrate W.

The fixed piece 1332 is, for example, a metal plate extending in the vertical direction. The upper end of the fixed piece 1332 is fixed to the frame 1331b. The lower end of the fixed piece 1332 is inserted into the drive unit 1333.

The drive unit 1333 has, for example, a stepping motor and a rack and pinion. The drive unit 1333 moves the fixed piece 1332 in the vertical direction. When the drive unit 1333 moves the fixed piece 1332 in the vertical direction, the support frame 1331 fixed to the fixed piece 1332 moves in the vertical direction. This causes the holder 1310 fixed to the support frame 1331 to move in the vertical direction.

Next, the pre-alignment unit PU will be further described with reference to FIG. 6. FIG. 6 is a block diagram showing the configuration of the pre-alignment unit PU.

As shown in FIG. 6, the first optical head 1710 of the distance measurement device 1700 has a first light-emitting element 1711 that emits a first emitted light, and a first light-receiving element 1712 that receives light of the first emitted light emitted from the first light-emitting element 1711 that is reflected by the upper surface of the substrate W. The first light-emitting element 1711 is, for example, a semiconductor element, although it is not particularly limited thereto. In this embodiment, the first light-emitting element 1711 is, for example, a semiconductor laser. The first light-receiving element 1712 is, for example, a semiconductor element, although it is not particularly limited thereto. In this embodiment, the first light-receiving element 1712 is, for example, a photodiode. In this way, the first optical head 1710 has a first light-emitting element 1711 that emits a first emitted light, and a first light-receiving element 1712 that receives the light of the first emitted light emitted from the first light-emitting element 1711 that is reflected by the upper surface of the substrate W, making it possible to easily measure the distance to the upper surface of the substrate W held on the stage 1100.

The second optical head 1720 of the distance measurement device 1700 has a second light-emitting element 1721 that emits a second emitted light, and a second light-receiving element 1722 that receives light of the second emitted light emitted from the second light-emitting element 1721 that is reflected by the underside of the substrate W. The second light-emitting element 1721 is, for example, a semiconductor element, although it is not particularly limited thereto. In this embodiment, the second light-emitting element 1721 is, for example, a semiconductor laser. The second light-receiving element 1722 is, for example, a semiconductor element, although it is not particularly limited thereto. In this embodiment, the second light-receiving element 1722 is, for example, a photodiode. In this way, the second optical head 1720 has a second light-emitting element 1721 that emits a second emitted light, and a second light-receiving element 1722 that receives the light of the second emitted light emitted from the second light-emitting element 1721 that is reflected by the underside of the substrate W, making it possible to easily measure the distance to the underside of the substrate W held on the stage 1100.

The control device 1900 controls various operations of the pre-alignment unit PU. The control device 1900 causes the pre-alignment unit PU to correct positional misalignment of the substrate W relative to the stage 1100. The control device 1900 also causes the pre-alignment unit PU to measure the thickness of the substrate W.

The control device 1900 includes a control unit 1910 and a memory unit 1920. The control unit 1910 has a processor. The control unit 1910 has, for example, a central processing unit (CPU). Alternatively, the control unit 1910 may have a general-purpose computer.

In this embodiment, the control unit 1910 has a misalignment calculation unit 1911 and a thickness calculation unit 1912. The misalignment calculation unit 1911 calculates the amount of positional misalignment of the substrate W relative to the stage 1100 based on the detection result of the detection sensor 1600. The control unit 1910 corrects the position of the substrate W relative to the stage 1100 using the misalignment correction actuator 1300 based on the calculated amount of positional misalignment.

The thickness calculation unit 1912 calculates the thickness of the substrate W based on the measurement results of the first optical head 1710 and the measurement results of the second optical head 1720. Specifically, since the distance between the first optical head 1710 and the second optical head 1720 is constant, the thickness calculation unit 1912 calculates the thickness of the substrate W by subtracting the measurement result of the first optical head 1710 (the distance from the first optical head 1710 to the top surface of the substrate W) and the measurement result of the second optical head 1720 (the distance from the second optical head 1720 to the bottom surface of the substrate W) from the distance between the first optical head 1710 and the second optical head 1720.

The memory unit 1920 stores data and computer programs. The data specifies, for example, the processing content and processing procedure for correcting misalignment. The data also specifies, for example, the processing content and processing procedure for measuring the thickness of the substrate W.

The memory unit 1920 includes a main memory device and an auxiliary memory device. The main memory device is, for example, a semiconductor memory. The auxiliary memory device is, for example, a semiconductor memory and/or a hard disk drive. The memory unit 1920 may include removable media. The control unit 1910 executes a computer program stored in the memory unit 1920 to perform a position misalignment correction operation and a substrate W thickness measurement operation.

Next, a method for detecting the position of the substrate W using the detection sensor 1600 will be described with reference to Figures 7 and 8. Figure 7 is a schematic diagram for explaining a method for detecting the position of the substrate W using the detection sensor 1600. Figure 8 is a plan view showing the structure of the substrate W. Note that in Figure 7 and Figures 17 and 21 described below, the band-shaped light emitted from the light emission head 1610 is hatched to facilitate understanding.

As shown in FIG. 7, the light emission head 1610 is positioned above the edge of the substrate W so that the band of light extends in the radial direction of the substrate W. As a result, as described above, a portion of the band of light irradiates the top surface of the substrate W, and the remainder of the band of light passes through the side of the substrate W.

Here, if the substrate W is misaligned with respect to the stage 1100, the central axis (not shown) of the stage 1100 coincides with the rotation axis L1210 of the rotary actuator 1200, and therefore the central axis LW of the substrate W does not coincide with the rotation axis L1210 of the rotary actuator 1200. Therefore, when the stage 1100 is rotated around the rotation axis L1210 of the rotary actuator 1200, the central axis LW of the substrate W rotates around the rotation axis L1210. In other words, the substrate W rotates eccentrically. At this time, the amount of light (band-shaped light) emitted from the light emitting head 1610 that is blocked by the substrate W changes in synchronization with the rotation period of the substrate W. In other words, the amount of light received by the light receiving head 1620 changes in synchronization with the rotation period of the substrate W. This allows the misalignment calculation unit 1911 to calculate the amount of positional misalignment of the substrate W relative to the stage 1100 based on the amount of change in the amount of light received by the light receiving head 1620.

Also, as shown in FIG. 8, a notch WN is formed on the periphery of the substrate W. The notch WN is a V-shaped cutout. When the substrate W rotates around the rotation axis L1210, the amount of light blocked by the substrate W changes suddenly when the notch WN passes between the light emitting head 1610 and the light receiving head 1620. Specifically, when the notch WN passes between the light emitting head 1610 and the light receiving head 1620, the amount of light blocked by the substrate W suddenly decreases and then suddenly increases. Therefore, the deviation calculation unit 1911 can detect the timing when the notch WN passes between the light emitting head 1610 and the light receiving head 1620. Therefore, the deviation calculation unit 1911 can calculate the rotation angle position of the substrate W.

Next, a method for measuring the thickness of a substrate W using the distance measuring device 1700 will be described with reference to Figures 9 to 11. Figure 9 is a schematic diagram for explaining a method for measuring the thickness of a substrate W using the distance measuring device 1700. Figure 10 is a schematic diagram for explaining a method for measuring the distance to a substrate W in the circumferential direction using the distance measuring device 1700. Figure 11 is a schematic diagram for explaining a method for measuring the distance to a substrate W along the transport direction A using the distance measuring device 1700.

As shown in FIG. 9, the first optical head 1710 is positioned above the substrate W held on the stage 1100. In other words, the first optical head 1710 is disposed facing the upper surface Wa of the substrate W held on the stage 1100. The first optical head 1710 is also disposed such that the optical axis L1710 of the first emitted light emitted from the first optical head 1710 is located radially inward from the periphery of the upper surface Wa of the substrate W by a predetermined distance (e.g., 1 mm or more and 10 mm or less). Hereinafter, the optical axis L1710 of the first emitted light emitted from the first optical head 1710 may be referred to as the optical axis L1710 of the first optical head 1710.

The second optical head 1720 is positioned below the substrate W held on the stage 1100. In other words, the second optical head 1720 is disposed facing the lower surface Wb of the substrate W held on the stage 1100. The second optical head 1720 is also disposed such that the optical axis L1720 of the second emitted light emitted from the second optical head 1720 is located radially inward from the periphery of the lower surface Wb of the substrate W by a predetermined distance (e.g., 1 mm or more and 10 mm or less). Hereinafter, the optical axis L1720 of the second emitted light emitted from the second optical head 1720 may be referred to as the optical axis L1720 of the second optical head 1720.

In this embodiment, the optical axis L1720 of the second emitted light emitted from the second optical head 1720 is located on the same axis as the optical axis L1710 of the first emitted light emitted from the first optical head 1710. Therefore, the first optical head 1710 and the second optical head 1720 can simultaneously measure the distance to the upper surface Wa and the distance to the lower surface Wb at the same position on the substrate W.

In this embodiment, when the distance measuring device 1700 measures the distance to the substrate W, the distance measuring device 1700 measures the distance to the substrate W in a state where the positional deviation of the substrate W relative to the stage 1100 is corrected. In other words, the distance measuring device 1700 measures the distance to the substrate W in a state where the central axis LW of the substrate W coincides with the rotation axis L1210 of the rotation actuator 1200.

As shown in FIG. 10, when the positional misalignment of the substrate W relative to the stage 1100 has been corrected, the first emitted light emitted from the first optical head 1710 irradiates a position radially inward a predetermined distance (e.g., 1 mm or more and 10 mm or less) from the periphery of the upper surface Wa of the substrate W. In FIG. 10, for ease of understanding, the irradiation position P1710 by the first optical head 1710 is indicated by a small circle.

In this embodiment, when the distance to the substrate W is measured in the circumferential direction by the distance measuring device 1700, the stage 1100 is rotated around the rotation axis L1210 of the rotary actuator 1200. As a result, the substrate W rotates around the rotation axis L1210 of the rotary actuator 1200. At this time, since the central axis LW of the substrate W coincides with the rotation axis L1210, the irradiation position P1710 of the first optical head 1710 moves circumferentially at a position radially inward by a predetermined distance from the periphery of the upper surface Wa of the substrate W. In FIG. 10, the trajectory P1710a of the irradiation position P1710 is shown by a thick line. Note that, as with the first optical head 1710, the irradiation position of the second optical head 1720 also moves circumferentially at a position radially inward by a predetermined distance from the periphery of the lower surface Wb of the substrate W.

In addition, in this embodiment, while the rotary actuator 1200 rotates the stage 1100 holding the substrate W, the first optical head 1710 measures the distance to the upper surface Wa of the substrate W, and the second optical head 1720 measures the distance to the lower surface Wb of the substrate W.

Then, while the rotary actuator 1200 rotates the stage 1100 holding the substrate W, the thickness calculation unit 1912 calculates the thickness of the substrate W along the circumferential direction based on the measurement result of the first optical head 1710 measuring the distance to the upper surface Wa of the substrate W and the measurement result of the second optical head 1720 measuring the distance to the lower surface Wb of the substrate W.

11, in this embodiment, the distance measurement device 1700 measures the distance to the substrate W while the transport robot TR transports the substrate W in the transport direction A, which is horizontal to the stage 1100. Specifically, as described below, after the distance measurement device 1700 measures the distance to the substrate W in the circumferential direction, the transport arm 3510 of the transport robot TR holds the substrate W and transports the substrate W in the transport direction A relative to the stage 1100 in order to transport the substrate W to the joining unit JU. As a result, the irradiation position P1710 of the first optical head 1710 moves linearly so as to pass through the center (here, the center) of the upper surface Wa of the substrate W. In other words, the irradiation position P1710 moves on the center line of the substrate W. In FIG. 11, the trajectory P1710b of the irradiation position P1710 is shown by a thick line. As with the first optical head 1710, the irradiation position of the second optical head 1720 moves linearly so as to pass through the central portion (here, the center) of the lower surface Wb of the substrate W.

While the transport robot TR transports the substrate W in the transport direction A relative to the stage 1100, the first optical head 1710 measures the distance to the upper surface Wa of the substrate W, and the second optical head 1720 measures the distance to the lower surface Wb of the substrate W.

Then, while the transport robot TR transports the stage 1100 holding the substrate W in the transport direction A relative to the stage 1100, the thickness calculation unit 1912 calculates the thickness of the substrate W along the transport direction A based on the measurement result obtained by the first optical head 1710 measuring the distance to the upper surface Wa of the substrate W and the measurement result obtained by the second optical head 1720 measuring the distance to the lower surface Wb of the substrate W.

As described above with reference to Figures 1 to 11, in this embodiment, the misalignment correction actuator 1300 corrects the positional misalignment of the substrate W relative to the stage 1100 based on the calculation result of the misalignment calculation unit 1911. The thickness calculation unit 1912 calculates the thickness of the substrate W in the circumferential direction based on the measurement result of the first optical head 1710 measuring the distance to the upper surface Wa of the substrate W and the measurement result of the second optical head 1720 measuring the distance to the lower surface Wb of the substrate W while the rotation actuator 1200 rotates the stage 1100 holding the substrate W whose positional misalignment has been corrected. In addition, while the transport robot TR transports the misalignment-corrected substrate W in the transport direction A, which is horizontal to the stage 1100, the thickness calculation unit 1912 calculates the thickness of the substrate W along the transport direction A based on the measurement result of the first optical head 1710 measuring the distance to the upper surface Wa of the substrate W and the measurement result of the second optical head 1720 measuring the distance to the lower surface Wb of the substrate W. Therefore, since the thickness of the substrate W is calculated based on the measurement result of the first optical head 1710 and the second optical head 1720 measuring the distance to the substrate W with the misalignment of the substrate W relative to the stage 1100 corrected, the thickness of the substrate W can be measured with high accuracy.

In addition, by using the first optical head 1710 and the second optical head 1720 to measure the distance from above and below the substrate W, the thickness of the substrate W can be measured with high accuracy even if the substrate W is warped.

The first optical head 1710 and the second optical head 1720 measure the distance to the substrate W while the rotary actuator 1200 rotates the substrate W. Therefore, unlike when the first optical head 1710 and the second optical head 1720 are moved in the circumferential direction to measure the distance to the substrate W, or when the substrate W is translated in the horizontal direction, it is not necessary to secure a space for the first optical head 1710 and the second optical head 1720 to move, or a space for the substrate W to move. This prevents the pre-alignment unit PU from becoming too large.

In addition, the thickness calculation unit 1912 calculates the thickness of the substrate W along the circumferential direction and also calculates the thickness of the substrate W along the transport direction A. Therefore, the thickness of the substrate W can be measured with higher accuracy than when the thickness of the substrate W is calculated only along the circumferential direction or when the thickness of the substrate W is calculated only along the transport direction A.

As described above, while the transport robot TR transports the substrate W in the transport direction A, the thickness calculation unit 1912 calculates the thickness of the substrate W along the transport direction A based on the measurement result obtained by the first optical head 1710 measuring the distance to the upper surface Wa of the substrate W along a straight line passing through the center of the substrate W and the measurement result obtained by the second optical head 1720 measuring the distance to the lower surface Wb of the substrate W along a straight line passing through the center of the substrate W. Therefore, since the thickness of the substrate W can be calculated along a straight line passing through the center of the substrate W, the thickness of the substrate W can be easily and accurately measured.

As described above, when the holder 1310 holds the substrate W, the first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 move the holder 1310 horizontally relative to the stage 1100 based on the calculation results of the displacement calculation unit 1911, thereby correcting the positional displacement of the substrate W relative to the stage 1100. Therefore, the positional displacement of the substrate W relative to the stage 1100 can be easily corrected.

As described above, the pre-alignment unit PU has an alignment housing 1010 to which the first optical head 1710 and the second optical head 1720 are fixed. Therefore, unlike a case where a moving mechanism for moving the first optical head 1710 and the second optical head 1720 is provided, it is possible to prevent particles from being generated due to the driving of the moving mechanism.

In addition, as described above, the transport robot TR is disposed outside the alignment housing 1010. Therefore, compared to when the transport robot TR is disposed inside the alignment housing 1010, it is possible to prevent particles generated due to the operation of the transport robot TR from contaminating the inside of the alignment housing 1010.

As described above, the first optical head 1710 emits a first emitted light toward the upper surface Wa of the substrate W, and the second optical head 1720 emits a second emitted light toward the lower surface Wb of the substrate W. Therefore, the first optical head 1710 can easily measure the distance to the upper surface Wa of the substrate W, and the second optical head 1720 can easily measure the distance to the lower surface Wb of the substrate W.

Next, an example of the operation flow of the pre-alignment unit PU and the transport unit TU according to this embodiment will be described with reference to Figures 12 to 23. Figure 12 is a flowchart showing an example of the operation of the pre-alignment unit PU and the transport unit TU. Figures 13 to 23 are schematic diagrams for explaining an example of the operation of the pre-alignment unit PU and the transport unit TU. Note that in Figures 13 to 23, the number of support pins 1120 of the stage 1100 and the number of support pins 1312 of the holder 1310 are reduced in order to simplify the drawings.

In this embodiment, the operation of the pre-alignment unit PU and the transport unit TU includes steps S1 to S19. Steps S1, S3, S16, and S18 are executed by a control unit (not shown) of the transport unit TU. Steps S2, S4 to S15, S17, and S19 are executed by a control unit 1910 of the pre-alignment unit PU. Step S5 is an example of a "process for detecting the position of the substrate" of the present invention. Step S6 is an example of a "process for calculating the positional deviation of the substrate" of the present invention. Steps S7 to S11 are an example of a "process for correcting the positional deviation of the substrate" of the present invention. Step S13 is an example of a "process for calculating the thickness of the substrate along the circumferential direction" of the present invention. Step S19 is an example of a "process for calculating the thickness of the substrate along the transport direction" of the present invention.

As shown in FIG. 12, in step S1, a substrate W is loaded into the pre-alignment unit PU. Specifically, after receiving the substrate W from the center robot CR, the transport robot TR loads the substrate W into the pre-alignment unit PU. At this time, as shown in FIG. 13, the transport robot TR inserts the transport arm 3510 holding the substrate W into the pre-alignment unit PU through the opening window 1011c in the side wall 1011a. As a result, the substrate W held by the transport arm 3510 is positioned above the stage 1100 and the holder 1310.

Next, in step S2, the holder 1310 is raised to the raised position. Specifically, as shown in FIG. 14, the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. The lowered position is the height position of the holder 1310 shown in FIG. 13, where the support pins 1312 of the holder 1310 are lower than the support pins 1120 of the stage 1100. The raised position is the height position shown in FIG. 14, where the support pins 1312 of the holder 1310 are higher than the support pins 1120 of the stage 1100. The raised position is the height position where the support pins 1312 of the holder 1310 protrude above the upper surface 3510a of the transport arm 3510.

In step S2, the holder 1310 is raised to the raised position, so that the support pins 1312 of the holder 1310 protrude above the upper surface 3510a of the transport arm 3510. As a result, the substrate W is supported by the holder 1310 and separated from the transport arm 3510. In other words, the substrate W is transferred from the transport arm 3510 to the holder 1310.

Next, in step S3, the transport arm 3510 is retracted. Specifically, the transport driver 3520 of the transport robot TR retracts the transport arm 3510 into the transport unit TU through the opening window 1011c in the side wall 1011a (see FIG. 15).

Next, in step S4, the holder 1310 is lowered to the lowered position. Specifically, as shown in FIG. 16, the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position. As a result, the substrate W is lowered from a position above the stage 1100. As the holder 1310 is lowered to the lowered position in step S4, the support pins 1312 of the holder 1310 move lower than the support pins 1120 of the stage 1100, and the lower surface Wb of the substrate W comes into contact with the support pins 1120 of the stage 1100. As a result, the substrate W is supported by the support pins 1120, and the lower surface Wb of the substrate W is separated from the support pins 1312 of the holder 1310. In other words, the substrate W is transferred from the holder 1310 to the stage 1100.

When the substrate W is transferred from the holder 1310 to the stage 1100 in step S4, the central axis LW of the substrate W does not coincide with the rotation axis L1210 of the rotation actuator 1200 and the central axis (not shown) of the stage 1100. In other words, the center of the substrate W is misaligned with respect to the center of the stage 1100.

Next, in step S5, the detection sensor 1600 detects the position of the substrate W held by the stage 1100. Specifically, as shown in FIG. 17, the rotary actuator 1200 rotates the stage 1100 around the rotation axis L1210. As a result, the substrate W rotates around the rotation axis L1210. In step S5, the stage 1100 is rotated while placed at the reference position. Hereinafter, when the stage 1100 is placed at the reference position, the axis along which the central axis (not shown) of the stage 1100 and the rotation axis L1210 of the rotary actuator 1200 coincide is referred to as the reference axis LB. The positions of the reference position and the reference axis LB coincide, for example, with the central position of the alignment housing 1010 in a plan view, and do not move. The rotation speed of the stage 1100 and the substrate W is not particularly limited, but is, for example, 60 rpm (rotations per minute) or less to ensure the detection accuracy of the detection sensor 1600.

Then, while the substrate W is being rotated, the detection sensor 1600 detects the position of the substrate W. Specifically, as described above, the light emitting head 1610 emits a band of light toward the peripheral edge of the substrate W, and the light receiving head 1620 receives the light (band of light) emitted from the light emitting head 1610 that passes through the side of the substrate W. The detection sensor 1600 transmits a signal indicating the amount of light received to the control unit 1910.

Next, in step S6, the displacement calculation unit 1911 of the control unit 1910 calculates the amount of positional displacement of the substrate W relative to the stage 1100 based on the detection result of the detection sensor 1600. In this embodiment, the displacement calculation unit 1911 calculates the amount of positional displacement of the substrate W relative to the central axis (not shown) of the stage 1100 and the rotation axis L1210 of the rotation actuator 1200.

In addition, in this embodiment, the misalignment calculation unit 1911 detects the timing when the notch WN of the substrate W passes between the light emitting head 1610 and the light receiving head 1620 based on the detection result of the detection sensor 1600. The misalignment calculation unit 1911 then calculates the rotational angle position of the substrate W relative to the stage 1100. The rotational angle position is the position of the substrate W in the rotational direction of the stage 1100 relative to the stage 1100.

Next, in step S7, the stage 1100 is moved horizontally. Specifically, as shown in FIG. 18, the first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 move the stage 1100 and the substrate W horizontally based on the positional misalignment amount calculated by the misalignment calculation unit 1911 so that the central axis LW of the substrate W coincides with the reference axis LB. Note that in step S7, when the central axis LW of the substrate W coincides with the reference axis LB, the rotation axis L1210 of the rotation actuator 1200 is positioned at a position misaligned from the reference axis LB.

Next, in step S8, the holder 1310 is raised to the raised position. Specifically, as shown in FIG. 19, the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. As the holder 1310 is raised to the raised position, the support pins 1312 of the holder 1310 protrude above the support pins 1120 of the stage 1100. As a result, the substrate W is supported by the holder 1310 and separated from the support pins 1120 of the stage 1100. In other words, the substrate W is transferred from the stage 1100 to the holder 1310.

Next, in step S9, the stage 1100 is moved horizontally. Specifically, as shown in FIG. 20, the first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 move the stage 1100 horizontally the same distance in the opposite direction to step S7. As a result, the central axis (not shown) of the stage 1100 and the rotation axis L1210 of the rotation actuator 1200 coincide with the central axis LW of the substrate W and the reference axis LB.

Next, in step S10, the stage 1100 is rotated. Specifically, the rotation actuator 1200 rotates the stage 1100 based on the rotation angle position of the substrate W relative to the stage 1100 calculated by the misalignment calculation unit 1911. This causes the substrate W to be at a predetermined rotation angle position relative to the stage 1100. In other words, the notch WN of the substrate W is positioned directly above a specific position on the stage 1100.

Next, in step S11, the holder 1310 is lowered to the lowered position. Specifically, as shown in FIG. 16, similar to step S4, the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position. As a result, the substrate W is transferred from the holder 1310 to the stage 1100.

Note that, in the state where the substrate W is transferred from the holder 1310 to the stage 1100 in step S11, unlike step S4, the central axis LW of the substrate W approximately coincides with the rotation axis L1210 of the rotary actuator 1200, the central axis (not shown) of the stage 1100, and the reference axis LB. The positional deviation of the central axis LW of the substrate W relative to the rotation axis L1210 of the rotary actuator 1200, the central axis (not shown) of the stage 1100, and the reference axis LB is, for example, 0.1 mm or less.

Next, in step S12, the distance from the distance measuring device 1700 to the substrate W is measured in the circumferential direction. Specifically, as shown in FIG. 21, the rotary actuator 1200 rotates the stage 1100 about the rotation axis L1210 and the reference axis LB. This causes the substrate W to rotate about the central axis LW, the rotation axis L1210, and the reference axis LB.

Then, while the substrate W is being rotated, the distance measuring device 1700 measures the distance to the substrate W in the circumferential direction. Specifically, the first optical head 1710 emits a first emitted light toward the upper surface Wa of the substrate W, and receives the light of the first emitted light reflected by the upper surface Wa of the substrate W with the first light receiving element 1712. As a result, the first optical head 1710 measures the distance to the upper surface Wa of the substrate W held on the stage 1100. The second optical head 1720 emits a second emitted light toward the lower surface Wb of the substrate W, and receives the light of the second emitted light reflected by the lower surface Wb of the substrate W with the second light receiving element 1722. As a result, the second optical head 1720 measures the distance to the lower surface Wb of the substrate W held on the stage 1100. The distance measuring device 1700 transmits a signal indicating the measured distance to the control unit 1910. In FIG. 21, the first and second emitted lights are hatched to make it easier to understand.

In addition, in this embodiment, in step S12, similar to step S5, while the substrate W is being rotated, the detection sensor 1600 detects the position of the substrate W. The detection sensor 1600 transmits a signal indicating the amount of light received to the control unit 1910.

Next, in step S13, the thickness calculation unit 1912 of the control unit 1910 calculates the thickness of the substrate W in the circumferential direction based on the measurement results of the distance measurement device 1700. In this embodiment, the detection sensor 1600 detects the position of the notch WN of the substrate W simultaneously with the measurement by the distance measurement device 1700, so the thickness calculation unit 1912 calculates the thickness of the substrate W based on the detection results of the detection sensor 1600, while correlating the thickness of the substrate W with the circumferential position of the substrate W.

Next, in step S14, the position of the notch WN of the substrate W is adjusted. Specifically, the rotary actuator 1200 rotates the stage 1100 and the substrate W by a predetermined angle based on the detection result of the detection sensor 1600. At this time, the rotary actuator 1200 rotates the stage 1100 and the substrate W so that the notch WN of the substrate W is located at a predetermined position. In this embodiment, the rotary actuator 1200 rotates the stage 1100 so that the notch WN is located on a straight line that is parallel to the X direction and passes through the reference axis line LB. Here, the rotary actuator 1200 rotates the stage 1100 and the substrate W so that the notch WN is located on a straight line that is parallel to the X direction and passes through the reference axis line LB, and at a position close to the transport unit TU.

Next, in step S15, the holder 1310 is raised to the raised position. Specifically, as shown in FIG. 19, the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. As the holder 1310 is raised to the raised position, the support pins 1312 of the holder 1310 protrude above the support pins 1120 of the stage 1100. As a result, the substrate W is supported by the holder 1310 and separated from the support pins 1120 of the stage 1100. In other words, the substrate W is transferred from the stage 1100 to the holder 1310.

Next, in step S16, the transport arm 3510 of the transport robot TR is inserted into the pre-alignment unit PU. Specifically, as shown in FIG. 22, the transport robot TR inserts the transport arm 3510 into the pre-alignment unit PU through the opening window 1011c in the side wall 1011a. As a result, the transport arm 3510 is positioned between the holder 1310 and the substrate W.

Next, in step S17, the holder 1310 is lowered to the lowered position. Specifically, as shown in FIG. 23, the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position. As a result, the substrate W is lowered from a position above the transport arm 3510. As the holder 1310 is lowered to the lowered position, the support pins 1312 of the holder 1310 move below the upper surface 3510a of the transport arm 3510. As a result, the lower surface Wb of the substrate W comes into contact with the upper surface 3510a of the transport arm 3510, and the substrate W is supported by the transport arm 3510. Then, the lower surface Wb of the substrate W is separated from the support pins 1312 of the holder 1310. In other words, the substrate W is transferred from the holder 1310 to the transport arm 3510.

Next, in step S18, the substrate W is unloaded from the pre-alignment unit PU, and the distance from the distance measuring device 1700 to the substrate W is measured along the transport direction A. Specifically, the transport drive unit 3520 of the transport robot TR accommodates the transport arm 3510 holding the substrate W in the transport unit TU through the opening window 1011c of the side wall 1011a. That is, the transport robot TR transports the substrate W in the transport direction A (see FIG. 11) and accommodates it in the transport unit TU. As a result, the substrate W is unloaded from the pre-alignment unit PU to the transport unit TU. At this time, as described with reference to FIG. 11, the distance measuring device 1700 measures the distance to the substrate W while the transport robot TR transports the substrate W in the transport direction A relative to the stage 1100. As a result, the distance measuring device 1700 measures the distance to the substrate W along a straight line (center line) passing through the center of the substrate W.

Next, in step S19, the thickness calculation unit 1912 of the control unit 1910 calculates the thickness of the substrate W along the transport direction A based on the measurement results of the distance measurement device 1700. Then, the control unit 1910 transmits the calculation results of step S13 and step S19 to the control unit 91.

In this manner, the pre-alignment operation of the substrate W using the pre-alignment unit PU and the thickness measurement operation of the substrate W are completed.

Next, the joining unit JU of this embodiment will be described with reference to Figures 24 to 30. Figure 24 is a perspective view that shows a schematic structure of the joining unit JU. As shown in Figure 24, the joining unit JU comprises a base 2, a first substrate holder 10, a second substrate holder 20, a first movement actuator 100, and a second movement actuator 200. The first movement actuator 100 is an example of the "substrate holder actuator" of the present invention.

The base 2 supports the first substrate holder 10, the second substrate holder 20, the first moving actuator 100, and the second moving actuator 200. The base 2 is made of a material that is not easily deformed by the weight and heat of the first moving actuator 100 and the second moving actuator 200. The base 2 is made of, for example, stone. This makes it possible to increase the straightness and flatness of the base 2. In addition, a vibration isolation table (not shown) is arranged below the base 2. This makes it possible to suppress the transmission of vibrations from the floor 4012 (see FIG. 3) to the first substrate holder 10, the second substrate holder 20, the first moving actuator 100, and the second moving actuator 200. The vibration isolation table is not particularly limited, but may be, for example, an active vibration isolation table. The active vibration isolation table has, for example, a sensor that detects vibrations and an actuator that suppresses the transmission of vibrations.

In this embodiment, the first substrate holder 10 holds the back surface of the first substrate W1 (the surface opposite to the surface to be bonded to the second substrate W2). In this embodiment, the first substrate holder 10 turns the first substrate W1 upside down and moves the first substrate W1 up and down, as described below.

The first substrate holder 10 has a first stage 11 and a first holding part 12 fixed to the first stage 11. The first stage 11 has one surface 11a to which the first holding part 12 is attached. The first stage 11 is, for example, a plate having a rectangular parallelepiped shape. The first stage 11 is formed, for example, from a ceramic or metal with a small linear expansion coefficient.

The first holding part 12 holds the back surface of the first substrate W1. The holding method by the first holding part 12 is not particularly limited, but may be, for example, a vacuum type. In other words, the first holding part 12 adsorbs the back surface of the first substrate W1. The holding method by the first holding part 12 may be a clamping type that clamps the end of the first substrate W1. However, in order to prevent the first holding part 12 from contacting the second substrate holder 20 and/or the second substrate W2 when bonding the first substrate W1 and the second substrate W2, it is preferable that the holding method by the first holding part 12 is a vacuum type. The first holding part 12 is, for example, a plate having a cylindrical or disc shape. The first holding part 12 is, for example, formed of ceramic or metal with a small linear expansion coefficient.

In this embodiment, the second substrate holder 20 holds the back surface of the second substrate W2 (the surface opposite to the surface to be bonded to the first substrate W1). In this embodiment, the second substrate holder 20 moves the second substrate W2 horizontally along the upper surface of the base 2, as described below. In addition, the second substrate holder 20 rotates the second substrate W2 in the circumferential direction, as described below.

The second substrate holder 20 has a second stage 21 and a second holding part 22 fixed to the second stage 21. The second stage 21 holds the second holding part 22. The second stage 21 is, for example, a plate having a rectangular parallelepiped shape. The second stage 21 is formed, for example, from a ceramic or metal with a small linear expansion coefficient.

The second holding part 22 holds the back surface of the second substrate W2. The holding method by the second holding part 22 is not particularly limited, but may be, for example, a vacuum type. That is, the second holding part 22 adsorbs the back surface of the second substrate W2. The holding method by the second holding part 22 may be a clamping type that clamps the end of the second substrate W2. However, in order to prevent the second holding part 22 from contacting the first substrate holder 10 and/or the first substrate W1 when bonding the second substrate W2 and the second substrate W2 together, it is preferable that the holding method by the second holding part 22 is a vacuum type. The second holding part 22 is, for example, a plate having a cylindrical or disc shape. The second holding part 22 is, for example, formed of ceramic or metal with a small linear expansion coefficient.

The second holding part 22 is configured to be rotatable in the circumferential direction. Specifically, the second holding part 22 is configured to be rotatable around the center of the second holding part 22. In other words, the second holding part 22 rotates the second substrate W2 in the circumferential direction. The second holding part 22 also rotates the second substrate W2 in a horizontal plane.

The first movement actuator 100 moves the first substrate holder 10. In this embodiment, the first movement actuator 100 inverts the first substrate holder 10 upside down and moves the first substrate holder 10 upside down. This causes the first substrate W1 to be inverted upside down and moved upside down.

Specifically, the first movement actuator 100 has an inversion actuator 110, a lifting actuator 120, and a first gantry 130. In FIG. 24, the first gantry 130 is depicted by a two-dot chain line.

The inversion actuator 110 inverts the first substrate holder 10 upside down. The inversion actuator 110 has a rotating shaft 111 fixed to the first substrate holder 10, and a first rotation drive unit (not shown) that rotates the rotating shaft 111. The rotating shaft 111 may be composed of a single shaft that passes through the first substrate holder 10, or may be composed of a pair of shafts that are arranged on either side of the first substrate holder 10. The first rotation drive unit has, for example, a stepping motor. The first substrate holder 10 is inverted upside down by the first rotation drive unit rotating the rotating shaft 111 by 180 degrees.

In this embodiment, the joining unit JU includes an angle detection sensor 150. The angle detection sensor 150 detects the angle of the first substrate holder 10 relative to the second substrate holder 20. The angle detection sensor 150 includes, for example, three or more distance measurement sensors 151. The distance measurement sensor 151 is attached, for example, to one surface 11a of the first substrate holder 10 and measures the distance to the second substrate holder 20. The first substrate holder 10 can be arranged parallel to the second substrate holder 20 by rotating the rotating shaft 111 based on the detection result of the distance measurement sensor 151. This allows the first substrate W1 to be arranged parallel to the second substrate W2. The distance measurement sensor 151 may be attached to the second substrate holder 20 and measure the distance to the first substrate holder 10. The angle detection sensor 150 may include a sensor or device other than the distance measurement sensor 151 as long as it can detect the angle of the first substrate holder 10 relative to the second substrate holder 20.

The lifting actuator 120 moves the first substrate holder 10 up and down. The lifting actuator 120 has a pair of support members 121 and a pair of lifting mechanisms 122. The support members 121 support the inversion actuator 110. The support members 121 rotatably support the rotating shaft 111 of the inversion actuator 110. In addition, the lifting actuator 120 moves the first substrate holder 10 in the up and down direction based on the detection result of the distance measurement sensor 151, thereby keeping the distance between the first substrate W1 and the second substrate W2 within a predetermined range.

The lifting mechanism 122 has multiple movers 122a and multiple rails (not shown). The movers 122a are fixed to the support member 121. Two movers 122a are fixed to one support member 121. The movers 122a move along the rails. The movers 122a have, for example, a coil. The movers 122a also have an encoder that detects the distance moved along the rails (not shown). Note that not all movers 122a need to have a coil and an encoder, and one or more movers 122a may have a coil and an encoder.

A rail (not shown) is fixed to the first gantry 130 so as to extend in the vertical direction. The rail has a plurality of magnets. The magnets are arranged so that their north and south poles alternate along the vertical direction. By passing a current through the coil of the mover 122a, the mover 122a moves along the rail. As the mover 122a moves up and down along the rail, the first substrate holder 10 moves up and down.

The second movement actuator 200 moves the second substrate holder 20. In this embodiment, the second movement actuator 200 moves the second substrate holder 20 horizontally along the upper surface of the base 2. Also, in this embodiment, the second movement actuator 200 rotates the second holding portion 22 of the second substrate holder 20 in the circumferential direction. In other words, the second movement actuator 200 rotates the second holding portion 22 of the second substrate holder 20 in a horizontal plane.

Specifically, the second movement actuator 200 has a parallel movement unit 210 and a second rotation drive unit 230 (see FIG. 25). The parallel movement unit 210 moves the second substrate holder 20 in parallel along the upper surface of the base 2. The parallel movement unit 210 has a movement unit 211 that moves the second substrate holder 20 in the X direction, a movement unit 212 that moves the second substrate holder 20 in the Y direction, and a support base 213 that is disposed between the movement units 211 and 212.

Figure 25 is a schematic diagram showing the structure around the second substrate holder 20 of the joining unit JU from the X direction. As shown in Figures 24 and 25, the moving part 211 is disposed on a support base 213. The moving part 211 has a linear motor 2111 and a linear guide 2112. In this embodiment, the moving part 211 has a pair of linear motors 2111 and a pair of linear guides 2112.

The pair of linear motors 2111 are arranged on the outer side in the Y direction of the second stage 21 of the second substrate holder 20. The pair of linear motors 2111 are arranged at a predetermined distance from each other in the Y direction.

Each linear motor 2111 has a mover 2111a and a rail 2111b. The mover 2111a is fixed to the side of the second stage 21. The mover 2111a moves along the rail 2111b. The mover 2111a has, for example, a coil. The mover 2111a also has an encoder that detects the distance moved along the rail 2111b. Note that both of the pair of movers 2111a do not have to have a coil and an encoder, and one of the movers 2111a may have a coil and an encoder.

The rail 2111b is fixed to the support base 213 so as to extend in the X direction. The rail 2111b has multiple magnets. The multiple magnets are arranged so that the north poles and south poles are alternately aligned along the X direction. By passing a current through the coil of the mover 2111a, the mover 2111a moves along the rail 2111b. By moving the mover 2111a along the rail 2111b, the second substrate holder 20 moves in the X direction.

The pair of linear guides 2112 are disposed between the second stage 21 of the second substrate holder 20 and the support base 213. The pair of linear guides 2112 are disposed at a predetermined distance in the Y direction. The pair of linear guides 2112 are disposed along the pair of linear motors 2111, respectively.

Each linear guide 2112 has a mover 2112a and a rail 2112b. The mover 2112a is fixed to the lower surface of the second stage 21 (the surface facing the support base 213). The mover 2112a moves along the rail 2112b. The mover 2112a has, for example, a U-shaped cross section and sandwiches the rail 2112b from both sides in the Y direction. The rail 2112b is fixed to the support base 213 so as to extend in the X direction. The linear guide 2112 moves the second substrate holder 20 in a straight line with high precision.

Figure 26 is a schematic diagram showing the structure around the second substrate holder 20 of the joining unit JU from the Y direction. As shown in Figures 24 and 26, the moving part 212 is disposed on the base 2. The moving part 212 has a linear motor 2121 and a linear guide 2122. In this embodiment, the moving part 212 has a pair of linear motors 2121 and a pair of linear guides 2122.

The pair of linear motors 2121 are disposed between the support base 213 and the base 2. The pair of linear motors 2121 are disposed at a predetermined distance from each other in the X direction.

Each linear motor 2121 has a mover 2121a and a rail 2121b. The mover 2121a is fixed to the lower surface (the surface facing the base 2) of the support base 213. The mover 2121a moves along the rail 2121b. The mover 2121a has, for example, a coil. The mover 2121a also has an encoder that detects the distance moved along the rail 2121b. Note that both of the pair of movers 2121a do not have to have a coil and an encoder, and one of the movers 2121a may have a coil and an encoder.

The rail 2121b is fixed to the base 2 so as to extend in the Y direction. The rail 2121b has multiple magnets. The multiple magnets are arranged so that the north poles and south poles are alternately arranged along the Y direction. By passing a current through the coil of the mover 2121a, the mover 2121a moves along the rail 2121b. By moving the mover 2121a along the rail 2121b, the support base 213 and the second substrate holder 20 move in the Y direction.

The pair of linear guides 2122 are disposed between the support base 213 and the base 2. The pair of linear guides 2122 are disposed at a predetermined distance in the X direction. The pair of linear guides 2122 are disposed along the pair of linear motors 2121, respectively.

Each linear guide 2122 has a mover 2122a and a rail 2122b. The mover 2122a is fixed to the lower surface of the support table 213 (the surface facing the base 2). The mover 2122a moves along the rail 2122b. The mover 2122a has, for example, a U-shaped cross section and sandwiches the rail 2122b from both sides in the X direction. The rail 2122b is fixed to the base 2 so as to extend in the Y direction. The linear guide 2122 moves the support table 213 and the second substrate holder 20 in a straight line with high precision.

The second rotation drive unit 230 is attached to the lower part of the second holding part 22 of the second substrate holder 20. The second rotation drive unit 230 rotates the second holding part 22 in the circumferential direction. In other words, the second rotation drive unit 230 rotates the second substrate W2 in the circumferential direction within a horizontal plane. The second rotation drive unit 230 includes, for example, a motor. In this embodiment, the second rotation drive unit 230 includes a direct drive motor. This allows the rotation angle of the second substrate W2 to be controlled with high precision.

Figure 27 is a schematic diagram showing the structure around the support base 213 from below. As shown in Figures 25 and 27, the joining unit JU is equipped with a detection actuator 300. The detection actuator 300 detects the movement of one of the first substrate holder 10 and the second substrate holder 20 in the XY plane. In this embodiment, the detection actuator 300 detects the movement of the second substrate holder 20 in the XY plane.

Specifically, the detection actuator 300 has, for example, a two-dimensional scale 301 (hereinafter, referred to as the 2D scale 301) and a detection sensor 302. The 2D scale 301 is attached to the lower surface of the second stage 21 of the second substrate holder 20. The 2D scale 301 has a rectangular shape extending in the X and Y directions. The 2D scale 301 is, for example, a reflective diffraction grating scale. The 2D scale 301 is configured so that the grating spacing changes along the X and Y directions.

The support base 213 has an opening 213a. The opening 213a is located below the 2D scale 301. The opening 213a has an opening larger than the 2D scale 301.

The detection sensor 302 is attached to the upper surface of the base 2. The detection sensor 302 protrudes upward from the opening 213a of the support base 213. The detection sensor 302 may be located below the support base 213. The detection sensor 302 emits laser light toward the 2D scale 301 and receives the light reflected by the 2D scale 301. As the second substrate holder 20 moves, the light reception signal of the detection sensor 302 changes. This allows the amount of movement of the second substrate holder 20 in the X and Y directions to be detected.

Returning to FIG. 24, the joining unit JU will be further described. As shown in FIG. 24, the joining unit JU includes a first substrate detection sensor 310 and a first reference mask 410. The first substrate detection sensor 310 detects the first substrate W1. Specifically, the first substrate W1 has one or more alignment marks. The first substrate detection sensor 310 detects the alignment marks of the first substrate W1.

The first board detection sensor 310 is fixed to the second stage 21. The first board detection sensor 310 includes, for example, a camera. The first board detection sensor 310 includes an imaging element. For example, the imaging element is a CCD image sensor or a CMOS image sensor. The first board detection sensor 310 transmits the captured imaging data to the control device 90. The imaging data includes image data. In this embodiment, the first board detection sensor 310 has a camera 311. Note that the first board detection sensor 310 may have multiple cameras with different magnifications, similar to the second board detection actuator 320 described later.

The first substrate detection sensor 310 also detects the first reference mask 410. Specifically, the first reference mask 410 has an alignment mark. The first substrate detection sensor 310 detects the alignment mark of the first reference mask 410. The first substrate detection sensor 310 detects the first reference mask 410 when one surface 11a of the first stage 11 faces downward.

The first reference mask 410 is fixed to the first stage 11. The first reference mask 410 has a mark member 411 on which an alignment mark is formed, and a pair of supports 412 that support the mark member 411.

The mark member 411 has an alignment mark formed with high precision. For example, the alignment mark is formed by performing etching or the like on the mark member 411. The mark member 411 is formed, for example, from a material with a small linear expansion coefficient. The mark member 411 may also be formed, for example, from a material having translucency. In this embodiment, the mark member 411 is formed, for example, from glass that transmits visible light.

Here, the first substrate detection sensor 310 detects the alignment marks of the first substrate W1 and the alignment marks of the first reference mask 410, thereby detecting the relative position of the alignment marks of the first substrate W1 with respect to the alignment marks of the first reference mask 410. Specifically, the first substrate detection sensor 310 is moved horizontally with one surface 11a of the first stage 11 facing downward, thereby detecting the alignment marks of the first substrate W1 and the alignment marks of the first reference mask 410. At this time, the detection actuator 300 detects the direction and distance that the first substrate detection sensor 310 and the second substrate holder 20 have moved from when the alignment marks of the first substrate W1 are detected by the first substrate detection sensor 310 until when the alignment marks of the first reference mask 410 are detected. This allows the relative position of the alignment marks of the first substrate W1 with respect to the alignment marks of the first reference mask 410 to be detected.

The joining unit JU includes a second substrate detection actuator 320 and a second reference mask 420. The second substrate detection actuator 320 detects the second substrate W2. Specifically, the second substrate W2 has one or more alignment marks. The second substrate detection actuator 320 detects the alignment marks of the second substrate W2.

The joining unit JU includes a second gantry 350, and the second substrate detection actuator 320 is fixed to the second gantry 350. Note that in FIG. 24, a part of the second gantry 350 is depicted by a two-dot chain line. The second substrate detection actuator 320 includes, for example, a camera. The second substrate detection actuator 320 includes an imaging element. For example, the imaging element is a CCD image sensor or a CMOS image sensor. The second substrate detection actuator 320 transmits the captured imaging data to the control device 90. The imaging data includes image data.

In this embodiment, the second substrate detection actuator 320 has a camera 321 and a camera 322 with different magnifications. The camera 321 is a relatively low magnification camera. The camera 322 is a relatively high magnification camera. The camera 322 has a higher magnification than the camera 321. The camera 321 has a relatively large angle of view, making it easy to detect the alignment mark of the second substrate W2. On the other hand, the camera 322 has a relatively small angle of view and high magnification, making it possible to detect the alignment mark with high accuracy.

When detecting the alignment mark of the second substrate W2 by the second substrate detection actuator 320, the alignment mark is detected by the camera 321, and then the alignment mark is detected by the camera 322. For this reason, an operation of moving the second substrate detection actuator 320 (camera 321 and camera 322) is required between the detection by the camera 321 and the detection by the camera 322. However, to simplify the explanation, in the following, both the detection by the camera 321 and the detection by the camera 322 will be described as detection by the second substrate detection actuator 320. Also, the operation of moving the second substrate detection actuator 320 between the detection by the camera 321 and the detection by the camera 322 will be omitted.

The second substrate detection actuator 320 also detects the second reference mask 420. Specifically, the second reference mask 420 has an alignment mark. The second substrate detection actuator 320 detects the alignment mark of the second reference mask 420.

The second reference mask 420 is fixed to the second stage 21. The second reference mask 420 has a mark member 421 on which an alignment mark is formed, and a support 422 that supports the mark member 421.

The mark member 421 has an alignment mark formed with high precision. For example, the alignment mark is formed by performing etching or the like on the mark member 421. The mark member 421 is formed, for example, from a material with a small linear expansion coefficient. The mark member 421 may also be formed, for example, from a material having translucency. In this embodiment, the mark member 421 is formed, for example, from glass that transmits visible light. The mark member 421 may also be formed from a material that does not transmit visible light.

Here, the second substrate detection actuator 320 detects the alignment marks of the second substrate W2 and the alignment marks of the second reference mask 420, thereby detecting the relative position of the alignment marks of the second substrate W2 with respect to the alignment marks of the second reference mask 420. Specifically, the second substrate holder 20 and the second substrate W2 are moved in the horizontal direction to detect the alignment marks of the second substrate W2 and the alignment marks of the second reference mask 420. At this time, the detection actuator 300 detects the direction and distance that the second substrate holder 20 and the second substrate W2 have moved from when the alignment marks of the second substrate W2 are detected by the second substrate detection actuator 320 until when the alignment marks of the second reference mask 420 are detected. This makes it possible to detect the relative position of the alignment marks of the second substrate W2 with respect to the alignment marks of the second reference mask 420.

Figure 28 is a perspective view showing the structure of the joining unit JU from below. As shown in Figure 28, the joining unit JU is equipped with an imaging unit 50. In this embodiment, the imaging unit 50 transmits captured imaging data to the control device 90.

In this embodiment, the imaging unit 50 is fixed to the first substrate holder 10. Also, in this embodiment, the imaging unit 50 images the first reference mask 410 and the second reference mask 420. Specifically, the imaging unit 50 images the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420. In this embodiment, the imaging unit 50 simultaneously images the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420. In other words, the imaging unit 50 images the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420 within one screen.

In this embodiment, the imaging unit 50 is attached to the first stage 11. The imaging unit 50 may be attached, for example, to one surface 11a (see FIG. 24) of the first stage 11. The imaging unit 50 may also be attached, for example, to the first stage 11 so as to penetrate the first stage 11. In this embodiment, the imaging unit 50 is attached to the first stage 11 so as to penetrate the first stage 11 in the thickness direction.

When bonding the first substrate W1 held by the first substrate holder 10 and the second substrate W2 held by the second substrate holder 20, the first reference mask 410 and the second reference mask 420 are arranged opposite each other in the vertical direction. At this time, the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420 are arranged opposite each other in the vertical direction. However, in the XY plane, the positions of the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420 may or may not completely match. The alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420 only need to be arranged at positions where they are simultaneously imaged by the imaging unit 50.

The control unit 91 (see FIG. 1) controls the joining unit JU. Specifically, the control unit 91 controls the first moving actuator 100 and the second moving actuator 200.

The control unit 91, for example, controls the first movement actuator 100 to turn upside down the first substrate W1 that has been handed over from the transport robot TR to the first substrate holder 10 and is held by the first substrate holder 10. The control unit 91, for example, controls the first movement actuator 100 to move the inverted first substrate W1 downward, and bond the first substrate W1 and the second substrate W2 together.

The control unit 91 calculates the relative position of the alignment mark of the first substrate W1 with respect to the alignment mark of the first reference mask 410, for example, based on the detection results of the detection actuator 300 and the first substrate detection sensor 310. The control unit 91 also calculates the relative position of the alignment mark of the second substrate W2 with respect to the alignment mark of the second reference mask 420, for example, based on the detection results of the detection actuator 300 and the second substrate detection actuator 320. The control unit 91 also calculates the relative positional relationship between the alignment mark of the first reference mask 410 and the alignment mark of the second reference mask 420, for example, based on the detection results of the imaging unit 50. Therefore, the control unit 91 can calculate the relative positional relationship between the alignment mark of the first substrate W1 and the alignment mark of the second substrate W2, for example, based on the detection results of the detection actuator 300, the first substrate detection sensor 310, the second substrate detection actuator 320, and the imaging unit 50.

Note that, for example, calculating the relative position between the first reference mask 410 and the second reference mask 420, calculating the relative position between the first substrate holder 10 and the second substrate holder 20, and calculating the relative position between the first substrate W1 and the second substrate W2 are substantially the same as calculating the relative position of the second reference mask 420 with respect to the imaging unit 50.

The control unit 91 acquires the calculation results of the thickness calculation unit 1912 of the pre-alignment unit PU. The control unit 91 is an example of the "acquisition unit" of the present invention.

The control unit 91 generates mapping data for the first substrate W1 and mapping data for the second substrate W2 based on the thicknesses of the first substrate W1 and the second substrate W2 calculated by the pre-alignment unit PU. The mapping data indicates thickness information of the substrate W in each region when the substrate W is divided into a plurality of regions in a grid pattern. In this embodiment, the control unit 91 generates mapping data for the entire region of the substrate W by predicting the thickness of a portion of the substrate W (regions not calculated) based on the thickness calculation result of the substrate W along the circumferential direction and the thickness calculation result of the substrate W along the transport direction A.

In this embodiment, the control unit 91 controls the lifting actuator 120 to move the first substrate holder 10 relative to the second substrate holder 20 so that the distance between the first substrate W1 and the second substrate W2 is within a predetermined range based on the calculation result of the thickness calculation unit 1912. Therefore, the first substrate holder 10 can be moved relative to the second substrate holder 20 based on the thickness of the substrate W that is measured with high accuracy, so that the distance between the first substrate W1 and the second substrate W2 can be easily brought into the predetermined range.

Next, the bonding method of the bonding unit JU of this embodiment will be described with reference to Figures 29 and 30. Figure 29 is a flowchart showing the bonding method of the bonding unit JU. Figure 30 is a side view that shows a schematic state in which the first substrate W1 and the second substrate W2 are arranged opposite each other. Note that in Figure 30, the amount of change in thickness of the substrates W is shown to be extremely large for ease of understanding. In this embodiment, the bonding method of the bonding unit JU includes steps S101 to S111.

29, in step S101, the control unit 91 carries the first substrate W1 transferred from the pre-alignment unit PU to the transport robot TR into the joining unit JU. Specifically, the control unit 91 controls the transport robot TR to carry the first substrate W1 into the joining unit JU through the opening window 4011c (see FIG. 3). At this time, the transport robot TR transports the first substrate W1 with the surface of the first substrate W1 to be bonded to the second substrate W2 (hereinafter, sometimes referred to as the bonding surface) facing upward. Then, the transport robot TR delivers the first substrate W1 to the first substrate holder 10. At this time, the transport robot TR may deliver the first substrate W1 directly to the first substrate holder 10, or may deliver the first substrate W1 to the first substrate holder 10 via another device such as an adsorption chuck pin. The first substrate W1 is held by the first substrate holder 10 with the bonding surface facing upward.

Next, in step S102, the control unit 91 transports the second substrate W2 transferred from the pre-alignment unit PU to the transport robot TR into the joining unit JU. Specifically, the control unit 91 controls the transport robot TR to transport the second substrate W2 into the joining unit JU through the opening window 4011c (see FIG. 3). At this time, the transport robot TR transports the second substrate W2 with the surface of the second substrate W2 to be bonded to the first substrate W1 (hereinafter, sometimes referred to as the bonding surface) facing upward. Then, the transport robot TR delivers the second substrate W2 to the second substrate holder 20. At this time, the transport robot TR may directly deliver the second substrate W2 to the second substrate holder 20, or may deliver the second substrate W2 to the second substrate holder 20 via another device such as an adsorption chuck pin. The second substrate W2 is held by the second substrate holder 20 with the bonding surface facing upward.

Next, in step S103, the control unit 91 turns the first substrate W1 upside down. Specifically, the control unit 91 controls the first moving actuator 100 to turn the first substrate holder 10 upside down. As a result, the bonding surface of the first substrate W1 faces downward.

Next, in step S104, the control unit 91 moves the second substrate holder 20 to the reference position. Specifically, the control unit 91 controls the second movement actuator 200 to move the second substrate holder 20 to the reference position. The reference position is, for example, the position of the second substrate holder 20 when the center of the second holding portion 22 of the second substrate holder 20 is located directly below the center of the first holding portion 12 of the first substrate holder 10. In this state, the distance between the first substrate W1 and the second substrate W2 is, for example, several mm to several tens of mm or more.

Next, in step S105, the control unit 91 determines the amount of lowering of the first substrate W1 based on the mapping data of the first substrate W1 and the mapping data of the second substrate W2. Specifically, the control unit 91 identifies a region RW (see FIG. 30) in which the distance between the first substrate W1 and the second substrate W2 is the smallest based on the mapping data of the first substrate W1 and the mapping data of the second substrate W2.

Then, as shown in FIG. 30, the control unit 91 calculates the amount of descent of the first substrate W1 and the first substrate holder 10 so that the distance Lmin between the first substrate W1 and the second substrate W2 in the region RW is within a predetermined range. The predetermined range is, for example, from several μm to several tens of μm.

Next, in step S106, the control unit 91 lowers the first substrate W1. Specifically, the control unit 91 controls the lifting actuator 120 to lower the first substrate holder 10 by the amount of lowering calculated in step S105. This brings the distance between the first substrate W1 and the second substrate W2 within a predetermined range.

Next, in step S107, the control unit 91 acquires imaging data. Specifically, the control unit 91 acquires image data captured by the imaging unit 50. The image data includes information indicating the relative positional relationship between the alignment marks of the first reference mask 410 and the alignment marks of the second reference mask 420.

Next, in step S108, the control unit 91 detects the relative position between the alignment mark of the first reference mask 410 and the alignment mark of the second reference mask 420 based on the acquired imaging data. Here, since both the imaging unit 50 and the first reference mask 410 are fixed to the first substrate holder 10, the relative positional relationship between the imaging unit 50 and the first reference mask 410 does not change. Therefore, detecting the relative position between the alignment mark of the first reference mask 410 and the alignment mark of the second reference mask 420 is substantially the same as detecting the relative position indicating the relative position of the alignment mark of the second reference mask 420 with respect to the imaging unit 50. That is, in step S108, the control unit 91 detects the relative position of the alignment mark of the second reference mask 420 with respect to the imaging unit 50 based on the acquired imaging data. Then, the control unit 91 calculates the relative position of the second substrate holder 20 with respect to the first substrate holder 10, and the relative position of the second substrate W2 with respect to the first substrate W1, based on the relative position of the second reference mask 420 with respect to the imaging unit 50.

Next, in step S109, the control unit 91 calculates a correction amount for moving the second substrate holder 20 horizontally so that the central axis of the second substrate W2 coincides with the central axis of the first substrate W1, based on the relative position of the second substrate W2 with respect to the first substrate W1 calculated in step S108.

Next, in step S110, the control unit 91 aligns the first substrate holder 10 and the second substrate holder 20. Specifically, the control unit 91 drives the second moving actuator 200 based on the correction amount calculated in step S109. This aligns the first substrate holder 10 and the second substrate holder 20. As a result, the amount of positional misalignment between the first substrate W1 and the second substrate W2 is, for example, several tens of nm or less.

Next, in step S111, the control unit 91 bonds the first substrate W1 and the second substrate W2 together. Specifically, the control unit 91 controls the first moving actuator 100 to move the first substrate holder 10 and the first substrate W1 downward. This causes the first substrate W1 and the second substrate W2 to be bonded together.

In this manner, the bonding of the first substrate W1 and the second substrate W2 by the bonding unit JU is completed.

The above describes the embodiments of the present invention with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are only examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention.

For example, in the above embodiment, an example was described in which two substrates W whose thicknesses have been measured by a pre-alignment unit PU (substrate thickness measuring device) are bonded together in a bonding unit JU, but the present invention is not limited to this. Substrates W whose thicknesses have been measured by a substrate thickness measuring device may be used for a purpose other than bonding.

In addition, in the above embodiment, an example has been shown in which the pre-alignment unit PU, the transport unit TU, and the joining unit JU are arranged side by side, but the present invention is not limited to this. For example, the pre-alignment unit PU may be arranged adjacent to the joining unit JU, or may be arranged at a position away from the joining unit JU. Also, for example, the pre-alignment unit PU may be arranged directly above the joining unit JU.

In the above embodiment, an example is shown in which a transport robot TR is provided to transfer the substrate W to the pre-alignment unit PU, but the present invention is not limited to this. For example, a center robot CR may transfer the substrate W to the pre-alignment unit PU.

In the above embodiment, an example has been shown in which a transport unit TU housing a transport robot TR is provided between the pre-alignment unit PU and the joining unit JU, but the present invention is not limited to this. For example, the pre-alignment unit PU may be disposed adjacent to the joining unit JU, and the pre-alignment unit PU or the joining unit JU may be equipped with the transport robot TR.

In addition, in the above embodiment, an example has been shown in which the detection sensor 1600 has a light emission head 1610 and a light receiving head 1620, but the present invention is not limited to this. For example, the detection sensor 1600 may have a CCD image sensor or a CMOS image sensor. Then, the position of the substrate W held on the stage 1100 may be detected based on an image captured by the CCD image sensor or the CMOS image sensor.

In addition, in the above embodiment, an example has been shown in which the pre-alignment unit PU has the control unit 1910, but the present invention is not limited to this. For example, the control unit 91 of the substrate bonding system 1 may also function as the control unit 1910. In other words, the control unit 91 may have, for example, a misalignment calculation unit and a thickness calculation unit.

In addition, in the above embodiment, an example of an operational flow of the pre-alignment unit PU and the transport unit TU is shown in which the substrate W is loaded into the pre-alignment unit PU (step S1 in FIG. 12) and then the holder 1310 is lifted (step S2 in FIG. 12), but the present invention is not limited to this. For example, the substrate W may be loaded into the pre-alignment unit PU after the holder 1310 is lifted. With this configuration, it is possible to shorten the tact time.

The present invention is suitable for use in substrate thickness measurement devices, substrate bonding systems, and substrate thickness measurement methods.

1: Substrate bonding system 10: First substrate holder 20: Second substrate holder 91: Control unit (acquisition unit)
100: First moving actuator (substrate holder actuator)
1010: Alignment housing (housing)
1011c: Opening window (window)
1100: stage 1200: rotation actuator 1300: displacement correction actuator 1310: holder 1330: holder movement actuator 1400: first horizontal movement actuator (horizontal movement actuator)
1500: Second horizontal movement actuator (horizontal movement actuator)
1600: Detection sensor 1710: First optical head (first distance measuring sensor)
1711: First light emitting element 1712: First light receiving element 1720: Second optical head (second distance measuring sensor)
1721: second light emitting element 1722: second light receiving element 1911: displacement calculation unit 1912: thickness calculation unit 3510: transport arm JU: bonding unit (substrate bonding apparatus)
L1710: Optical axis L1720: Optical axis PU: Pre-alignment unit (substrate thickness measuring device)
S5: Step (process of detecting the position of the substrate)
S6: Step (process of calculating positional deviation of substrate)
S7 to S11: Steps (processes for correcting positional deviation of the substrate)
S13: Step (process of calculating the thickness of the substrate along the circumferential direction)
S19: Step (process of calculating the thickness of the substrate along the transport direction)
TR: Transport robot (transport actuator)
W: Substrate W1: First substrate W2: Second substrate Wa: Upper surface Wb: Lower surface

Claims (11)

a stage for holding the substrate horizontally;
a detection sensor for detecting a position of the substrate held by the stage;
a displacement calculation unit that calculates a positional displacement amount of the substrate with respect to the stage based on a detection result of the detection sensor;
a misalignment correction actuator that corrects a positional misalignment of the substrate with respect to the stage;
a rotation actuator that rotates the stage while holding the substrate;
a first distance measuring sensor disposed above the substrate held by the stage and configured to measure a distance to an upper surface of the substrate;
a second distance measuring sensor disposed below the substrate held by the stage and configured to measure a distance to a lower surface of the substrate;
a thickness calculation unit that calculates a thickness of the substrate based on a measurement result of the first distance measuring sensor and a measurement result of the second distance measuring sensor,
the misalignment correction actuator corrects a positional misalignment of the substrate with respect to the stage by moving one of the substrate and the stage in a horizontal direction relative to the other of the substrate and the stage based on a calculation result of the misalignment calculation unit;
The thickness calculation unit is
calculating a thickness of the substrate along a circumferential direction based on a measurement result of the first distance measuring sensor measuring a distance to the upper surface of the substrate and a measurement result of the second distance measuring sensor measuring a distance to a lower surface of the substrate while the rotary actuator rotates the stage holding the substrate whose positional deviation has been corrected;
A substrate thickness measuring device that calculates a thickness of the substrate along a transport direction that is horizontal to the stage while a transport actuator transports the substrate after position misalignment has been corrected, based on a measurement result obtained by the first distance measuring sensor measuring the distance to the top surface of the substrate and a measurement result obtained by the second distance measuring sensor measuring the distance to the bottom surface of the substrate. the transport actuator transports the substrate in the transport direction such that the first distance measuring sensor and the second distance measuring sensor measure the distance along a straight line passing through a center of the substrate;
2. The substrate thickness measuring device of claim 1, wherein the thickness calculation unit calculates the thickness of the substrate along the transport direction based on a measurement result obtained by the first distance measuring sensor measuring the distance to the top surface of the substrate along a straight line passing through the center of the substrate and a measurement result obtained by the second distance measuring sensor measuring the distance to the bottom surface of the substrate along a straight line passing through the center of the substrate while the transport actuator transports the substrate in the transport direction. The deviation correction actuator includes:
a holder that moves in a vertical direction relative to the stage to transfer the substrate between the stage and the holder;
a holder movement actuator that moves the holder in a vertical direction relative to the stage;
a horizontal movement actuator that moves one of the holder and the stage in a horizontal direction relative to the other of the holder and the stage;
2. The substrate thickness measuring device of claim 1, wherein when the holder holds the substrate by the holder movement actuator moving the holder upward relative to the stage, the horizontal movement actuator corrects positional misalignment of the substrate relative to the stage by moving one of the holder and the stage horizontally relative to the other of the holder and the stage based on the calculation result of the misalignment calculation unit. The substrate thickness measuring device according to any one of claims 1 to 3, further comprising a housing that houses the first distance measuring sensor and the second distance measuring sensor and to which the first distance measuring sensor and the second distance measuring sensor are fixed. the transport actuator is disposed outside the housing,
The substrate thickness measuring device according to claim 4 , wherein the housing has a window through which a transfer arm of the transfer actuator passes. the first distance measuring sensor includes a first optical head that emits a first emission light toward an upper surface of the substrate;
The substrate thickness measuring device according to claim 1 , wherein the second distance measuring sensor includes a second optical head that emits a second emission light toward a lower surface of the substrate. The substrate thickness measuring device according to claim 6, wherein the optical axis of the second emitted light from the second optical head is coaxial with the optical axis of the first emitted light from the first optical head. The first optical head includes:
A first light emitting element that emits the first emitted light;
a first light receiving element that receives light reflected by an upper surface of the substrate out of the first emitted light emitted from the first light emitting element,
The second optical head is
A second light emitting element that emits the second emitted light;
The substrate thickness measuring device according to claim 6 , further comprising: a second light receiving element that receives light reflected by a lower surface of the substrate, out of the second emitted light emitted from the second light emitting element. The substrate thickness measuring device according to claim 1 ,
a substrate bonding apparatus that bonds a first substrate and a second substrate whose thicknesses have been measured by the substrate thickness measuring apparatus. The substrate bonding apparatus includes:
a first substrate holder that horizontally holds the first substrate;
a second substrate holder that horizontally holds the second substrate;
a substrate holder actuator that moves one of the first substrate holder and the second substrate holder in a vertical direction relative to the other of the first substrate holder and the second substrate holder;
an acquisition unit that acquires a calculation result of the thickness calculation unit of the substrate thickness measuring device,
10. The substrate bonding system of claim 9, wherein the substrate holder actuator moves one of the first substrate holder and the second substrate holder relative to the other of the first substrate holder and the second substrate holder so that the distance between the first substrate and the second substrate is within a predetermined range based on a calculation result of the thickness calculation unit. detecting a position of a substrate held horizontally on a stage;
calculating a positional deviation of the substrate relative to the stage based on a detection result of the position of the substrate;
correcting a positional deviation of the substrate relative to the stage by moving one of the substrate and the stage in a horizontal direction relative to the other of the substrate and the stage based on a result of calculating the positional deviation;
calculating a thickness of the substrate along a circumferential direction based on a measurement result of a first distance measuring sensor measuring a distance to an upper surface of the substrate and a measurement result of a second distance measuring sensor measuring a distance to a lower surface of the substrate while the stage holding the substrate whose positional deviation has been corrected is rotating;
and calculating a thickness of the substrate along a transport direction based on a measurement result of the first distance measuring sensor measuring the distance to the top surface of the substrate and a measurement result of the second distance measuring sensor measuring the distance to the bottom surface of the substrate while the substrate after position misalignment correction is transported in the transport direction that is horizontal to the stage.

Images