JP2019062244A - Semiconductor wafer mounting method and semiconductor wafer mounting apparatus - Google Patents

Abstract

An adhesive tape for supporting is accurately adhered over a back surface of a semiconductor wafer having an annular convex portion formed on the back surface and a ring frame. A semiconductor wafer W is housed and held in one of a pair of housings with the adhesive tape T stuck to a ring frame f and the back surface of the wafer W closely facing each other, and the adhesive tape T is held by both housings. A chamber is formed by being sandwiched. A pressure difference is generated in two spaces in the chamber separated by the adhesive tape T, and the adhesive tape T is bent in a concave shape while being heated and is adhered to the back surface of the wafer W. After eliminating the differential pressure and heating, the adhesive tape T is attached to the wafer W while the adhesive tape T is reheated. [Selection] Fig. 25

Description

  The present invention relates to a semiconductor wafer mounting method and semiconductor wafer mounting method for mounting a semiconductor wafer (hereinafter, appropriately referred to as a “wafer”) at the center of a ring frame via a supporting adhesive tape.

  In order to reinforce the wafer whose rigidity is reduced by back grinding, only the central portion is ground leaving the back outer periphery. That is, the annular convex portion is formed on the outer periphery of the back surface of the wafer. Before dicing the wafer, the wafer is mounted at the center of the ring frame via a supporting adhesive tape.

  For example, the wafer is placed and held on the holding table provided on the lower housing of the upper and lower pair of housings, and the ring frame is held on the frame holding table surrounding the lower housing. After adhering the adhesive tape to the ring frame, the adhesive tape on the inner side of the ring frame is sandwiched by both housings to form a chamber. At this time, since the adhesive tape and the back surface of the wafer are closely opposed to each other, a differential pressure is generated in the two spaces partitioned by the adhesive tape, and the hemispherical elastic body adheres radially outward from the center of the adhesive tape. The tape is pressed and attached to the back of the wafer.

  After completion of the application of the adhesive tape, the first pressing member blows a gas from the first pressing member onto the adhesive tape which is not fully adhered at the inner corner portion of the annular convex portion and performs the second attaching process (see Patent Document 1) ).

Unexamined-Japanese-Patent No. 2013-232582

  In the conventional adhesive tape bonding method, the adhesive tape can be adhered to the inner corner of the annular convex portion. However, since time passes after the adhesive tape is attached, there is a problem that the adhesive tape peels from the corner toward the center of the wafer.

  The present invention has been made in view of such circumstances, and an adhesive tape is efficiently attached to the back surface of a semiconductor wafer having an annular convex portion formed on the back surface, and the adhesive tape is attached to the back surface of the semiconductor wafer. A main object of the present invention is to provide a semiconductor wafer mounting method and a semiconductor wafer mounting device that can suppress peeling.

The present invention has the following configuration in order to achieve such an object.
That is, it is a method of mounting a semiconductor wafer in which a semiconductor wafer is mounted on a ring frame through an adhesive tape for support.
The semiconductor wafer has an annular convex portion on the outer periphery of the back surface,
The semiconductor wafer is held by a holding table provided on one of a pair of housings in a state where the adhesive tape attached to the ring frame and the back surface of the semiconductor wafer are closely opposed to each other, and the adhesive tape is sandwiched by both housings. Forming a chamber with
A first bonding process of generating a differential pressure in two spaces in the housing partitioned by the adhesive tape and indenting and curving the adhesive tape while heating the adhesive tape to affix the back surface of the semiconductor wafer;
A second affixing step of adhering the adhesive tape while reheating the adhesive tape after eliminating the differential pressure and heating in the chamber;
It is characterized by having.

  (Operation / Effect) According to the above method, heating is performed to soften the adhesive tape. By creating a differential pressure in the two spaces in the chamber in this state, the adhesive tape can be concavely curved toward the back surface of the wafer. That is, the adhesive tape is attached while being stretched radially from the center to the outer periphery of the semiconductor wafer. Therefore, the entrapment of air at the adhesive interface between the adhesive tape and the semiconductor wafer can be suppressed.

  Further, along with the concave curvature of the adhesive tape, the tension acting on the adhesive tape increases toward the outer periphery of the semiconductor wafer. Therefore, the pressure-sensitive adhesive tape attached to the semiconductor wafer in the first affixing process does not contact or partially contact the entire surface at and near the inner corner of the annular convex portion.

  Thereafter, when the pressure difference is eliminated by returning the inside of the chamber to the atmospheric state, the tensile stress accumulated in the adhesive tape by the tension at the time of application acts on the adhesive tape and peels off from the corner over time. Come. The cause of peeling in the first application process is at least one of the elongation of the pressure-sensitive adhesive tape mainly based on elastic deformation due to tension and the pressure-sensitive adhesive which is not sufficiently softened.

  However, by reheating the adhesive tape in the second affixing process after the first affixing process, at least one of the deformation of the adhesive tape in the vicinity of the corner and the pressure-sensitive adhesive is sufficiently softened. As a result, it is possible to suppress peeling of the adhesive tape from the semiconductor wafer.

  In the above method, after the adhesive tape is exposed to the atmosphere at room temperature while being carried out of the chamber in the first affixing process and transferred to the different holding table, the adhesive tape is heated while heating the semiconductor wafer on the holding table. It is preferable to perform the 2nd affixing process which pastes.

  According to this method, since the adhesive tape is exposed to the air at room temperature in the process of transfer to another holding table, the base material of the adhesive tape is slightly cooled and hardened. Therefore, the adhesive tape in the portion in close contact with the semiconductor wafer is easily fixed.

  Moreover, this invention takes the following structures in order to achieve such an object.

That is, it is a semiconductor wafer mounting apparatus for mounting a semiconductor wafer on a ring frame through a supporting adhesive tape,
A first holding table for holding the semiconductor wafer having an annular convex portion on the outer periphery of the back surface;
A frame holding unit for holding the ring frame to which the adhesive tape is attached;
A chamber comprising a pair of housings which accommodate the first holding table and sandwich the adhesive tape attached to the ring frame;
A first heater for heating the adhesive tape in the chamber;
A control unit for generating a differential pressure in two spaces in the chamber partitioned by the adhesive tape and attaching the heated adhesive tape to the back surface of the semiconductor wafer while making it concavely curved; ,
A second holding table for holding a mount frame formed by bonding a semiconductor wafer to an adhesive tape by the first bonding mechanism;
A second heater for reheating the adhesive tape on the second holding table;
A transport mechanism for transporting the mount frame from the first bonding mechanism to the second holding table;
A second bonding mechanism for bonding the adhesive tape while reheating the adhesive tape with the second heater after eliminating the differential pressure in the chamber and the heating by the first heater;
It is characterized by having.

  (Operation and Effect) According to this configuration, the adhesive tape can be attached to the entire back surface of the semiconductor wafer by the first attaching mechanism. Thereafter, in the semiconductor wafer already mounted on the ring frame on the second holding table, the adhesive tape from the vicinity of the inner corner to the corner of the annular convex portion is reheated. That is, only the part that is not in close contact with the semiconductor wafer can be in close contact with the wafer. Therefore, the above method can be suitably implemented.

In the above configuration, the first bonding mechanism may include a tape supply unit that supplies an adhesive tape of a size that covers the ring frame.
A tape application mechanism for applying an adhesive tape to one of the joint portions of the ring frame and the housing;
A cutting mechanism for cutting the adhesive tape on the ring frame;
A peeling mechanism that peels off the circularly cut adhesive tape;
A tape recovery unit for recovering the adhesive tape after peeling;
Preferably,

  According to this configuration, the adhesive tape can be cut in the process of attaching the adhesive tape to the back surface of the semiconductor wafer in the chamber. Therefore, the sticking time of the adhesive tape can be shortened.

  According to the semiconductor wafer mounting method and semiconductor wafer mounting method of the present invention, the adhesive tape for support attached to the back surface of the semiconductor wafer having the annular convex portion formed on the outer periphery of the back surface is the inner corner of the annular convex portion. It is possible to suppress peeling from the part.

It is a partially broken perspective view of a semiconductor wafer. It is a perspective view of the back side of a semiconductor wafer. It is a partial longitudinal cross-sectional view of a semiconductor wafer. It is a top view which shows the structure of the mounting apparatus of a semiconductor wafer. It is a front view of the mounting apparatus of a semiconductor wafer. It is a front view showing a part of wafer conveyance mechanism. It is a top view which shows a part of wafer conveyance mechanism. It is a front view of a wafer conveyance apparatus. It is a top view which shows the movement structure of a wafer conveyance apparatus. It is a front view of a frame conveyance device. It is a front view of a reversing unit. It is a top view of inversion unit. It is a front view of a pusher. It is a top view of a pusher. It is a front view of a 1st sticking unit. It is a fragmentary sectional view which shows schematic structure of a tape sticking part. It is a longitudinal cross-sectional view of a chamber. It is a top view of a tape cutting mechanism. It is a schematic diagram which shows the adhesion | pasting operation | movement of an adhesive tape. It is a schematic diagram which shows the adhesion | pasting operation | movement of an adhesive tape. It is a schematic diagram which shows the adhesion | pasting operation | movement of an adhesive tape. It is a schematic diagram which shows the adhesion | pasting operation | movement of an adhesive tape. It is a schematic diagram which shows the adhesion | pasting operation | movement of an adhesive tape. It is a perspective view of a mount frame. It is a schematic diagram of a 2nd sticking process. It is a figure which shows the comparison of the peeling measurement result implemented with the Example apparatus and the comparative example apparatus. It is a schematic diagram which measures the slack of an adhesive tape. It is a figure which shows the comparison of the slack measurement result implemented with the Example apparatus and the comparative example apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Semiconductor wafer>
As shown in FIGS. 1 to 3, the semiconductor wafer W (hereinafter simply referred to as “wafer W”) is backgrind processed in a state where the protective tape PT is attached to the surface on which the pattern is formed to protect the surface. It is done. The back surface is back-grounded leaving an outer peripheral portion of about 2 mm in the radial direction. That is, while the flat recessed part b is formed in a back surface, what was processed into the shape by which the cyclic | annular convex part r was left along the outer periphery is used. For example, it is processed so that the depth d of the flat recess b may be several hundred μm, and the wafer thickness t in the grinding area may be several tens μm. Therefore, the annular convex portion r formed on the outer periphery of the back surface functions as an annular rib that enhances the rigidity of the wafer W, and suppresses the bending deformation of the wafer W in handling and other processing steps.

<Mounting device for semiconductor wafer>
A plan view of a semiconductor wafer mounting apparatus is shown in FIG.

  As shown in FIG. 4, this mounting apparatus has a convex basic unit formed of a horizontally long rectangular portion A and a projecting portion B which is connected at the central portion of the rectangular portion A and protrudes upward, and a protrusion It is configured to have a marking unit C connected to the basic unit in a space on the left side of part B. In the following description, the longitudinal direction of the rectangular portion A will be referred to as the left and right direction, and the horizontal direction orthogonal to this will be referred to as the lower side and the upper side.

  The wafer transfer mechanism 1 is disposed on the right side of the rectangular portion A. Two containers 2 accommodating wafers W are placed in parallel on the lower right side of the rectangular portion A. At the lower left end of the rectangular portion A, a recovery unit 3 for recovering the mount frame MF shown in FIG. 24 in which the mounting of the wafer W is completed is disposed.

  The aligner 4, the first holding table 5, the frame supply unit 6, and the reversing unit 7 are arranged in order from the upper right of the rectangular portion A. A second holding table 8 described later is disposed below the reversing unit 7. Further, a pusher 9 which slides in the upper part of the reversing unit 7 is provided.

  The protruding portion B is a first bonding unit 10 for bonding the supporting adhesive tape T (dicing tape) to the ring frame f and for bonding the adhesive tape T to the wafer W.

  In the wafer transfer mechanism 1, as shown in FIG. 5, a wafer transfer device 15 supported so as to reciprocate horizontally on the right side of a guide rail 14 horizontally and horizontally mounted above the rectangular portion A; A frame transfer device 16 supported on the left side so as to be movable left and right is provided.

  The wafer transfer device 15 is configured to transfer the wafer W taken out from any one of the containers 2 left and right and back and forth, and to reverse the attitude of the wafer W from front to back.

  As shown in FIGS. 6 and 8, the wafer transfer apparatus 15 is equipped with a left and right movable movable table 18 which can move laterally along the guide rails 14. A back and forth movable movable table 20 is provided so as to be movable back and forth along a guide rail 19 provided on the left and right movable movable table 18. Further, a holding unit 21 for holding the wafer W is provided at the lower part of the back and forth movable platform 20 so as to be vertically movable.

  As shown in FIGS. 6 and 7, a drive pulley 23 which is driven forward and reverse by a motor 22 is pivotally supported near the right end of the guide rail 14, and a free rotation pulley 24 is axially supported at the center of the guide rail 14. It is supported. The slide engaging portion 18 a of the left and right movable movable table 18 is connected to the belt 25 wound around the drive pulley 23 and the idle pulley 24, and the left and right movable movable table 18 is rotated by forward and reverse rotation of the belt 25. It is moved to the left and right.

  As shown in FIG. 9, a drive pulley 27 which is driven forward and reverse by a motor 26 is pivotally supported near the upper end of the left and right movable movable base 18, and a free rotation pulley 28 is provided near the lower end of the left and right movable movable base 18. It is pivotally supported. The slide engaging portion 20 a of the back and forth movable movable table 20 is connected to the belt 29 wound around the drive pulley 27 and the idle pulley 28, and the back and forth movable movable table 20 is rotated by forward and reverse rotation of the belt 29. It is supposed to be moved back and forth.

  As shown in FIG. 8, the holding unit 21 is screwed up and down by a motor 31 along a vertical frame portion of the inverted L-shaped support frame 30 connected to the lower portion of the back and forth movable platform 20. Lifting platform 32, a pivoting platform 34 pivotally supported on the lifting platform 32 via a pivot shaft 33 so as to be pivotable about a vertical support shaft p, a pivot linked to winding shaft 33 via a belt 35 Motor, a holding arm 38 pivotally supported on the lower part of the rotation base 34 via a rotation shaft 37 so as to be able to turn around the horizontal direction support shaft q and a rotation interlock between winding shafts 37 via a belt 39 It comprises the reverse motor 40 etc.

  The holding arm 38 has a horseshoe shape. The holding surface of the holding arm 38 is provided with a plurality of suction pads 41 slightly projecting. Further, the holding arm 38 is communicatively connected to the pneumatic device via a flow passage formed therein and a connection flow passage connected on the proximal end side of the flow passage.

  By using the movable structure described above, the wafer W held by suction is moved back and forth, moved leftward and rightward, and pivoted about the vertical support shaft p by the holding arm 38, and around the horizontal support shaft q shown in FIG. The wafer W can be turned upside down by the reverse rotation.

  As shown in FIG. 10, the frame transfer device 16 includes a vertical frame 44 connected to the lower part of the back and forth movable platform 43, an elevating frame 45 supported so as to be able to slide up and down along the vertical frame 44, and an elevating frame 45. Bending and extending link mechanism 46 for moving up and down, motor 47 for driving this bending and extending link mechanism 46 in forward and reverse bending, suction plate 48 for sucking wafer W mounted on the lower end of raising and lowering frame 45 and suction for adsorbing ring frame f A plurality of suction pads 49 disposed around the plate 48 are provided. Therefore, the frame conveyance device 16 can suction and hold the ring frame f and the mount frame MF placed and held on the first holding table 5 and convey the ring frame f and the front and rear, right and left, and left and right. The suction pad 49 is slidable in the horizontal direction corresponding to the size of the ring frame f.

  The first holding table 5 is a metal chuck table having a size equal to or larger than that of the wafer W, as shown in FIGS. 15 to 17, and is communicatively connected to an external vacuum device 95 through a flow path 94. It is done. Further, the first holding table 5 is equipped with a plurality of supporting pins 50.

  The pins 50 are disposed at equal intervals on a predetermined circumference of the first holding table 5. That is, the pin 50 is configured to be movable up and down at the holding surface of the first holding table 5 by an actuator such as a cylinder. The tip of the pin 50 is made of an insulator or covered with an insulator.

  The first holding table 5 is formed with an annular convex portion that contacts and supports only the outer peripheral region of the wafer W. Also, the heater 107 is embedded inside. The first holding table 5 is housed in a lower housing 11A that constitutes a chamber 11 described later. The lower housing 11A is provided with a frame holding portion 51 that surrounds the lower housing 11A. The frame holding portion 51 is configured such that when the ring frame f is placed, the ring frame f and the cylindrical top portion of the lower housing 11A are flat.

  As shown in FIG. 4, the first holding table 5 is laid between the position where the wafer W in the rectangular portion A is set and the position where the first tape application unit 10 in the protruding portion B is attached by a drive mechanism (not shown). It can be reciprocated along the rail 58.

  The frame supply unit 6 stores a pullout-type cassette in which a predetermined number of ring frames f are stacked and stored.

  As shown in FIGS. 11 and 12, the reversing unit 7 is a receiving frame that can be rotated about a horizontal support shaft r by a rotary actuator 61 on a lifting platform 60 that can move up and down along a vertical rail 59 set up and fixed. 62 is mounted in a cantilevered manner, and chuck claws 63 are provided at the base and the tip of the receiving frame 62 so as to be rotatable around a support shaft s, respectively. The reversing unit 7 receives the mount frame MF whose circuit surface is downward from the frame transfer device 16 and reverses it, and then turns the circuit pattern surface upward.

  The second holding table 8 reciprocates along the rail 58C between the receiving position of the mount frame MF immediately below the reversing unit 7 and the printing position of the marking unit C. As shown in FIG. 25, the second holding table 8 is a chuck table having a size capable of attracting and holding the entire back surface of the mount frame MF. The second holding table 8 is. It is formed of metal or ceramic porous. A heater is embedded in the second holding table 8.

  The pusher 9 stores the mount frame MF placed on the second holding table 8 in the mount frame recovery unit 3. The specific configuration is shown in FIG. 13 and FIG.

  The pusher 11 is provided with a fixed receiving piece 66 and a chucking piece 68 opened and closed by a cylinder 67 on the upper part of a movable table 65 moving horizontally along the rail 64. The fixed receiving piece 66 and the chucking piece 68 are configured to hold one end of the mount frame MF from above and below. The lower part of the movable table 65 is connected to the belt 70 rotated by the motor 69, and the movable table 65 is reciprocated to the left and right by forward and reverse operation of the motor 69.

  As shown in FIG. 15, the first bonding unit 10 is composed of a tape supply unit 71, a separator recovery unit 72, a tape bonding unit 73, a tape recovery unit 74, and the like. Each component will be described in detail below.

  The tape supply unit 71 is configured to peel off the separator S by the peeling roller 75 in the process of supplying the adhesive tape T from the supply bobbin loaded with the original fabric roll on which the adhesive tape T for support is wound. It is done. The supply bobbin is interlocked and connected to the electromagnetic brake and has a suitable rotational resistance. Therefore, excessive tape feeding from the supply bobbin is prevented.

  The tape supply unit 71 is configured to apply a tension by pushing down the adhesive tape T by the dancer roller 78 at the tip by swinging the swing arm 77 connected to the cylinder 76.

  The separator recovery unit 72 is provided with a recovery bobbin for winding the separator S peeled off from the adhesive tape T. The recovery bobbin is rotationally driven forward and reverse by a motor.

  The tape application unit 73 includes the chamber 11, a tape application mechanism 81, a tape cutting mechanism 82, and the like. The tape bonding mechanism 81 corresponds to the bonding mechanism of the present invention, and the tape cutting mechanism 82 corresponds to the cutting mechanism.

  The chamber 11 is composed of a lower housing 11A that reciprocally moves the rectangular portion A and the tape bonding portion 73, and an upper housing 11B configured to be movable up and down by the projecting portion B. Both housings 11A and 11B have an inner diameter smaller than the width of adhesive tape T. The lower cylindrical portion of the lower housing 11A is rounded, and is subjected to release processing such as fluorine processing.

  The upper housing 11B is provided in the lifting and lowering drive mechanism 84 as shown in FIG. The lift drive mechanism 84 includes a lift 87 movable along a rail 86 vertically disposed at the back of the vertical wall 85, a movable frame 88 supported by the lift 87 so as to be adjustable in height, and the movable An arm 89 extends forward from the frame 88. The upper housing 11B is attached to a support shaft 90 extending downward from the tip end of the arm 89.

  The lifting table 87 is configured to be screw fed and raised and lowered by rotating the screw shaft 91 forward and reverse by means of a motor 92.

  Both the housings 11A and 11B are connected in communication with a vacuum device 95 via a flow path 94, as shown in FIG. A solenoid valve 96 is provided in the flow passage 94 on the upper housing 11B side. Moreover, the flow path 99 provided with the solenoid valve 97,98 for open | release to air | atmosphere is connected by both housing 11A, 11B, respectively. Further, the upper housing 11B is communicatively connected to a flow passage 101 provided with a solenoid valve 100 for adjusting the internal pressure once reduced by leak. The opening and closing operation of the solenoid valves 96, 97, 98, and 100 and the operation of the vacuum device 95 are performed by the control unit 102.

  Referring back to FIG. 15, the tape pasting mechanism 81 is horizontally and horizontally arranged along the guide rails 105 and the guide rails 105 provided on the left and right support frames 104 erected on the apparatus base 103 with the first holding table 5 interposed therebetween. The movable table 106 is movable, the sticking roller 109 is pivotally supported by a bracket connected to the end of the cylinder provided on the movable table 106, and the nip roller 110 disposed on the side of the tape collecting portion 72.

  The movable table 106 is constituted by a belt 113 wound around a drive pulley 111 for forward and reverse rotation pivotally supported by a drive device fixedly provided on the apparatus base 103 and a free-running pulley 112 pivotally supported on the support frame 104 side. The drive is transmitted, and is configured to move horizontally along the guide rails 105.

  The nip roller 110 is composed of a feed roller 114 driven by a motor and a pinch roller 115 moved up and down by a cylinder.

  The tape cutting mechanism 82 is, as shown in FIG. 16, disposed in a lift drive mechanism 84 that raises and lowers the upper housing 11B. That is, the boss portion 117 which rotates around the support shaft 90 via the bearing 116 is provided. As shown in FIG. 18, the boss portion 117 is provided with four support arms 118 to 121 extending radially in the center.

  A cutter bracket 123 supporting a disk-shaped cutter 122 is mounted vertically movably at the tip of one of the support arms 118, and the pressing roller 124 is pivoted at the tips of the other support arms 119 to 121. It is mounted so that it can move up and down via 125.

  A connection portion 126 is provided at the upper portion of the boss portion 117, and the connection portion 126 is drivingly connected to the rotation shaft of the motor 127 provided in the arm 89.

  As shown in FIG. 15, the tape recovery section 74 is provided with a recovery bobbin for winding up the unnecessary adhesive tape T peeled off after the cutting. The recovery bobbin is rotationally driven forward and reverse by a motor (not shown).

  The marking unit C is configured to read the ID imprinted on the wafer W with a reader such as an optical sensor, for example, to bar code the ID into a two-dimensional or three-dimensional one, and print and attach the bar code.

  As shown in FIG. 5, the recovery unit 3 is provided with a cassette 130 for loading and recovering the mount frame MF. The cassette 130 is provided with a vertical rail 132 connected and fixed to the apparatus frame 131, and a lift platform 134 screwed up and down by a motor 133 along the vertical rail 132. Therefore, the recovery unit 3 is configured to place the mount frame MF on the elevator platform 134 and to lower the pitch by lowering.

  Next, the operation of mounting the wafer W on the ring frame f through the adhesive tape T using the apparatus of the above embodiment will be described.

  The transfer of the ring frame f from the frame supply unit 6 to the frame holding unit 51 of the lower housing 11A and the transfer of the wafer W from the container 2 to the first holding table 5 are simultaneously performed.

  One frame transfer device 16 sucks the ring frame f from the frame supply unit 6 and transfers the ring frame f to the frame holding unit 51. When the frame holding unit 51 releases the suction and ascends, the ring frame f is aligned by the support pins. That is, the ring frame f stands by until the wafer W is transported while being set in the frame holding unit 51.

  The other transfer device 15 inserts the holding arm 38 between the wafers W stored in multiple stages, suctions out from the circuit formation surface of the wafer W via the protective tape PT, carries it out, and transfers it to the aligner 4 Do.

  The aligner 4 sucks the center of the wafer W by a suction pad protruding from the center. At the same time, the transfer device 15 releases the suction of the wafer W and retracts the wafer W upward. The aligner 4 aligns the wafer W while holding and rotating the wafer W with a suction pad based on a notch or the like.

  When alignment is completed, the suction pad holding the wafer W is protruded from the surface of the aligner 4. The transfer device 15 moves to that position, and suctions and holds the wafer W from the front side. The suction pad releases the suction and descends.

  The transfer device 15 moves onto the first holding table 5 and delivers the wafer W to the supporting pins 50 protruding from the first holding table 5 with the surface with the protective tape facing downward. The pin 50 descends when the wafer W is received.

  When the first holding table 5 and the frame holding unit 51 suck the wafer W and the frame holding unit 51 sucks and holds the ring frame f, the lower housing 11A moves along the rail 58 toward the tape sticking mechanism 82 side.

  As shown in FIG. 19, when the lower housing 11A reaches the tape application position of the tape application mechanism 82, the application roller 109 descends, and as shown in FIG. 20, the ring frame f and lower while rolling on the adhesive tape T. The adhesive tape T is pasted over the top of the housing 11A. A predetermined amount of adhesive tape T is fed from the tape supply unit 71 while peeling off the separator S in conjunction with the movement of the sticking roller 109.

  When the application of the adhesive tape T to the ring frame f is completed, as shown in FIG. 21, the upper housing 11B is lowered. Along with this lowering, the adhesive tape T whose adhesive surface is exposed between the outer periphery of the wafer W and the inner diameter of the ring frame f is held between the upper housing 11B and the lower housing 11A to constitute the chamber 11. At this time, the adhesive tape T functions as a sealing material, and the upper housing 11B side and the lower housing 11B side are divided to form two spaces.

  The wafer W located in the lower housing 11A is closely opposed to the adhesive tape T with a predetermined clearance.

  The control unit 102 operates the heater 107 to heat the adhesive tape T from the lower housing 11A side, and operates the vacuum device 95 to close the electromagnetic valves 97, 98, and 100 shown in FIG. Depressurize the inside of 11B and the inside of lower housing 11A. At this time, the degree of opening of the solenoid valve 96 is adjusted so that the pressure in both housings 11A and 11B is reduced at the same speed.

  When the pressure in the two housings 11A and 11B is reduced to a predetermined pressure, the control unit 102 closes the solenoid valve 96 and stops the operation of the vacuum device 95.

  The control unit 102 gradually raises the inside of the upper housing 11B to a predetermined pressure while adjusting the degree of opening of the electromagnetic valve 100 to cause leakage. At this time, the air pressure in the lower housing 11A is lower than the air pressure in the upper housing 11B, and the pressure difference causes the adhesive tape T to be drawn from its center toward the lower housing 11A as shown in FIG. That is, the adhesive tape T is attached radially from the center of the wafer W toward the outer periphery while being concavely curved. At this time, the air at the corner portion inside the annular convex portion r is evacuated, and the adhesive tape T is adhered in a state where the gap is crushed.

  When the pressure in the upper housing 11B reaches a preset air pressure, the control unit 102 adjusts the opening degree of the electromagnetic valve 98 to make the pressure in the lower housing 11A the same as the pressure in the upper housing 11B. Thereafter, as shown in FIG. 23, the control unit 102 raises the upper housing 11B to open the inside of the upper housing 11B to the atmosphere, and fully opens the electromagnetic valve 98 to open the atmosphere to the lower housing 11A side.

  While the adhesive tape T is attached to the wafer W in the chamber 11, the tape cutting mechanism 82 operates. At this time, as shown in FIGS. 21 and 22, the cutter 122 cuts the adhesive tape T attached to the ring frame f into the shape of the ring frame f, and the pressing roller 124 follows the cutter 122 to make the ring frame The tape cutting portion on f is pressed while rolling. That is, when the upper housing 11B is lowered to constitute the chamber 11 by the lower housing 11A, as shown in FIG. 15, the cutter 122 and the pressing roller 124 of the tape cutting mechanism 82 also reach the cutting action position.

  Since the first application of the adhesive tape T to the wafer W and the cutting of the adhesive tape T are completed when the upper housing 11B is lifted, the pinch roller 115 is lifted to release the nip of the adhesive tape T. Thereafter, the nip roller 115 is moved, and the unnecessary adhesive tape T after cutting is taken up and collected toward the tape collection unit 74, and the adhesive tape T of a predetermined amount is fed out from the tape supply unit 71.

  When the peeling of the adhesive tape T is completed and the nip roller 115 and the attaching roller 109 return to the initial position, as shown in FIG. 23, the ring frame f and the mount frame MF with the adhesive tape T adhered to the back are held. The lower housing 11A moves to the unloading position on the rectangular portion A side.

  The mount frame MF that has reached the unloading position is delivered from the frame transport device 16 to the reversing unit 7. The reversing unit 7 upside down while holding the mount frame MF. That is, the circuit pattern surface faces upward. As shown in FIG. 25, the reversing unit 7 is mounted on the second holding table 8 with the mount frame MF turned upside down.

  The wafer W is subjected to a second bonding process by reheating by the heater 108 embedded in the second holding table 8. The processing time is set to be the same as the time during which the chamber 11 performs the first bonding process. When the second pasting process is completed, the second holding table 8 moves along the rail 58C to the printing position (label pasting position) of the marking unit C. When the second holding table 8 reaches the pasting position, the ID imprinted on the wafer W is read by an optical sensor or a camera. The marking unit C creates a label corresponding to the ID and attaches it to the wafer W.

  When the attachment of the label is completed, the second holding table 8 is moved to the unloading position on the rectangular portion A side. When the second holding table 8 reaches the unloading position, the pusher 9 grips the mount frame MF and transports the mount frame MF to the collection unit 3.

  Thus, one round operation of mounting the wafer W on the ring frame f via the adhesive tape T is completed. Thereafter, the above process is repeated until the number of mount frames MF reaches a predetermined number.

  The comparative example which performed the 1st sticking process without heating an adhesive tape by the 1st sticking unit 10 using the said Example apparatus, and the 1st sticking process while heating a sticky tape by the 1st sticking unit 10 After that, a comparative experiment with an example in which the second bonding process by reheating was performed on the second holding table 8 was performed.

  The used wafer W utilized the 200-mm thing which formed the cyclic | annular convex part r in the back surface as mentioned above. In addition, a protective tape PT is attached to the surface of the wafer W. As the adhesive tape, WS-01 manufactured by Nitto Denko Corporation was used. The bonding conditions in the present example used differential pressure and heating in the chamber 11 as the first bonding process, and used only reheating of the wafer W on the second holding table 8 as the second bonding process. In the first and second application processes, heating was performed at 80 ° C. for 1 minute while applying a differential pressure. In the bonding conditions of the comparative example, the adhesive tape T was bonded to the wafer W by applying a pressure difference of 1 minute without heating in the chamber 11.

  The result of peeling of the adhesive tape produced after sticking the adhesive tape T on the said conditions is shown by FIG. That is, the peeling which accompanies immediately after completion of affixing processing until 72 hours passes at room temperature was measured. Peeling was measured as the distance of the air gap 200 shown in FIG. 25 formed by peeling from the corner inside the convex portion toward the center of the wafer.

  As a result of the measurement, immediately after the bonding, in the present example and the comparative example, the gap formed without the pressure-sensitive adhesive tape adhering was 0.05 mm. However, in the comparative example, as time passes, the peeling of the pressure-sensitive adhesive tape T expands and reaches 0.6 mm after the final 72 hours.

  On the other hand, in the present embodiment, the peeling converges after 48 hours and becomes 0.3 mm. Therefore, it is improved by 50% over the comparative example.

  As described above, according to the present embodiment, by performing the second bonding process while reheating with the second holding table, the adhesive tape T which is not in close contact with the inner corner portion of the annular convex portion r is softened. It can be made to adhere closely. Therefore, it can suppress that the adhesive tape T peels from a corner and is expanded after affixing process.

  After three experiments under the same conditions, the slack of the adhesive tape T was measured. Specifically, as shown in FIG. 27, the ring frame f of the mount frame MF was placed, and the distance the wafer W fell by its own weight was measured as the slack of the adhesive tape. Specifically, the reference distance without slack is H1, and the distance of H2 further lowered from the H1 is added. The measurement was performed at the center of the wafer W.

  The results are shown in FIG. That is, the average of the sag was 3.7 mm in the case where one bonding process was performed only with the differential pressure without heating in the comparative example. On the other hand, in the case of performing two bonding processes by the differential pressure and heating and reheating of the present example, the average of the slack was 1.3 mm. That is, the slack of adhesive tape T which arose at the time of 1st application was improved by the heating at the time of 2nd application by performing affixing process twice like a present Example. That is, the slack caused by being elastically deformed by being held between the pair of upper and lower housings is returned to the original state by the heating. Therefore, by improving the slack, it is possible to divide into chips with high accuracy in the dicing process in the subsequent step.

  In the apparatus of this embodiment, since the first bonding process and the second bonding process are performed at different positions, processing can be performed more efficiently than processing at the same place.

  In addition, it is also possible to implement this invention in the following forms.

  In the apparatus of the above embodiment, a heater may be embedded in the upper housing 11B to heat the adhesive tape T from above and below.

DESCRIPTION OF SYMBOLS 1 ... Conveying mechanism 5 ... 1st holding table 6 ... Frame supply part 7 ... Reversing unit 8 ... 2nd holding table 9 ... Pusher 10 ... 1st sticking unit 11 ... Chamber 11A ... Lower housing 11B ... Upper housing 81 ... Tape sticking mechanism 82 ... tape cutting mechanism 102 ... control unit W ... semiconductor wafer f ... ring frame T ... adhesive tape PT ... protective tape

Claims (4)

A semiconductor wafer mounting method for mounting a semiconductor wafer on a ring frame through an adhesive tape for support, comprising:
The semiconductor wafer has an annular convex portion on the outer periphery of the back surface,
The semiconductor wafer is held by a holding table provided on one of a pair of housings in a state where the adhesive tape attached to the ring frame and the back surface of the semiconductor wafer are closely opposed to each other, and the adhesive tape is sandwiched by both housings. Forming a chamber with
A first bonding process of generating a differential pressure in two spaces in the housing partitioned by the adhesive tape and indenting and curving the adhesive tape while heating the adhesive tape to affix the back surface of the semiconductor wafer;
A second affixing step of adhering the adhesive tape while reheating the adhesive tape after eliminating the differential pressure and heating in the chamber;
A method of mounting a semiconductor wafer, comprising: In the method of mounting a semiconductor wafer according to claim 1,
The adhesive tape is exposed to the atmosphere at room temperature while being carried out of the chamber in the first affixing process and conveyed to the different holding tables while the semiconductor wafer is heated on the holding table, and then the adhesive tape is adhered A mounting method of a semiconductor wafer characterized by performing a pasting process. A semiconductor wafer mounting apparatus for mounting a semiconductor wafer on a ring frame through a supporting adhesive tape, comprising:
A first holding table for holding the semiconductor wafer having an annular convex portion on the outer periphery of the back surface;
A frame holding unit for holding the ring frame to which the adhesive tape is attached;
A chamber comprising a pair of housings which accommodate the first holding table and sandwich the adhesive tape attached to the ring frame;
A first heater for heating the adhesive tape in the chamber;
A control unit for generating a differential pressure in two spaces in the chamber partitioned by the adhesive tape and attaching the heated adhesive tape to the back surface of the semiconductor wafer while making it concavely curved; ,
A second holding table for holding a mount frame formed by bonding a semiconductor wafer to an adhesive tape by the first bonding mechanism;
A second heater for reheating the adhesive tape on the second holding table;
A transport mechanism for transporting the mount frame from the first bonding mechanism to the second holding table;
A second bonding mechanism for bonding the adhesive tape while reheating the adhesive tape with the second heater after eliminating the differential pressure in the chamber and the heating by the first heater;
A semiconductor wafer mounting apparatus comprising: In the semiconductor wafer mounting apparatus according to claim 3,
The first application mechanism includes a tape supply unit for supplying an adhesive tape having a size covering a ring frame;
A tape application mechanism for applying an adhesive tape to one of the joint portions of the ring frame and the housing;
A cutting mechanism for cutting the adhesive tape on the ring frame;
A peeling mechanism that peels off the circularly cut adhesive tape;
A tape recovery unit for recovering the adhesive tape after peeling;
A semiconductor wafer mounting apparatus comprising:

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