JP6622140B2 - Chuck table mechanism and transfer method - Google Patents

Description

  The present invention relates to a chuck table mechanism for holding a plate-like object such as a semiconductor wafer having a protective tape attached thereto, and a conveying method.

  In the semiconductor device manufacturing process, devices such as ICs and LSIs are formed in a plurality of regions partitioned by dividing lines called streets arranged on the surface of a semiconductor wafer having a substantially disk shape. Then, by cutting the semiconductor wafer along the streets, the semiconductor wafer is divided into regions where devices are formed, and individual semiconductor chips are manufactured.

  In order to form such a semiconductor chip thinly, a technique called a pre-dicing method is disclosed in Patent Document 1. When the semiconductor wafer is divided by the first dicing method, a cutting groove that does not penetrate to the back surface is formed on the front surface of the semiconductor wafer by so-called half cut. Then, after sticking a protective tape on the surface of the semiconductor wafer, the semiconductor wafer is sucked and held through the protective tape by a chuck table of a grinding mechanism, and the back surface of the semiconductor wafer is ground and thinned. By cutting the groove from the back side by this grinding, the semiconductor wafer is divided (divided into individual pieces) into individual semiconductor chips. The semiconductor wafer that has been diced after the previous dicing is sucked on the entire surface by a transfer pad, transferred to a chuck table (spinner table) of a cleaning mechanism, and transferred to the next process or a storage cassette after cleaning. In such transport, the suction of the chuck table is released after the back side of the semiconductor wafer is sucked with the transport pad while sucking the protective tape attached to the separated semiconductor wafer with the chuck table. Then, the semiconductor wafer is detached from the chuck table and carried out by raising the transfer pad.

JP 2003-17442 A

  When the tip dicing method is performed as described above, the semiconductor wafer is divided into a plurality of semiconductor chips by grinding, so the chuck table suction force in the grinding mechanism and cleaning mechanism are compared so that the position of each semiconductor chip does not move. Become stronger. In this state, when the suction of the chuck table is instantaneously released to transport the semiconductor wafer from the chuck table, the sticking tension generated when the protective tape is stuck is momentarily released. For this reason, when the suction force of the transport pad is weaker than that of the chuck table, the semiconductor wafer to which the protective tape is attached is warped and partially separated from the transport pad, so that the suction force of the transport pad is sufficient. There is a problem that it falls without acting or a transport error occurs.

  This invention is made | formed in view of this point, and it aims at providing the chuck table mechanism and the conveying method which can convey favorably the plate-shaped objects, such as a semiconductor wafer with which the protective tape was stuck. .

  The chuck table mechanism of the present invention includes a chuck table having a holding surface for sucking and holding a plate-like object via a protective tape for the plate-like object to which the protective tape is attached, and a communication path communicating with the holding surface, and a communication path A suction source connected to the suction passage through the suction passage, a first electromagnetic on-off valve disposed near the suction source of the suction passage, a blow fluid connected to the communication passage through the blow fluid supply passage, In a chuck table mechanism comprising a second electromagnetic on-off valve disposed in the fluid supply passage, pressure detecting means disposed in the suction passage near the communication passage for detecting the pressure in the suction passage, and the pressure in the suction passage A release path that branches between the detection means and the first electromagnetic on-off valve and is released to the atmosphere through the release on-off valve; a first electromagnetic on-off valve based on a detection signal from the pressure detection means; Control the electromagnetic on-off valve and release on-off valve And a control means for controlling the opening and closing of the release on-off valve to release the detection signal from the pressure detection means to a predetermined value when releasing the suction holding of the plate-like object sucked and held by the chuck table. When it rises, the first electromagnetic on-off valve is closed and the second electromagnetic on-off valve is opened.

  In this configuration, a release path is formed by branching from the suction path that causes the holding surface of the chuck table to communicate with the suction source, and the suction path can be opened to the atmosphere by opening and closing the release path with the release opening / closing valve. Thus, before closing the suction path by the first electromagnetic on-off valve and releasing the suction by the suction source, after releasing the release path and raising the suction force of the chuck table to a predetermined value, the suction by the suction source is performed. It can be canceled. As a result, the sticking tension of the protective tape retained and retained by the suction force of the suction source can be released stepwise, and the warpage can be suppressed even if the plate-like object is separated. By suppressing such warpage, it is possible to maintain a state in which the plate-like object is in contact with the entire surface without being separated from the holding surface of the conveyance pad, and it is possible to perform good conveyance by sufficiently applying the holding force of the conveyance pad. it can.

  The transfer method of the present invention is a semiconductor in which a semiconductor wafer is separated into pieces by a tip dicing method in which a front surface side of a semiconductor wafer is half-cut, a protective tape is attached to the front surface side, and back surface grinding is performed to divide the semiconductor wafer into individual semiconductor chips A transfer method for transferring a singulated wafer from a chuck table holding surface of the chuck table mechanism in which a chip is sucked and held via a protective tape, and has a suction holding surface corresponding to the outer diameter of a semiconductor wafer. A suction step that abuts the suction holding surface of the transfer pad against the upper surface of the singulated wafer, and opening and closing of the release opening / closing valve of the chuck table mechanism to suck the protective tape attached to the singulated wafer. Release opening / closing valve opening step to reduce the holding force and release the sticking tension of the protective tape, transport pad contact step and After the release opening / closing valve opening step, when the detection signal from the pressure detecting means rises to a predetermined value, the first electromagnetic opening / closing valve is closed, the second electromagnetic opening / closing valve is opened, and the conveyance pad is contacted. A detaching step of applying a suction force to the singulated wafer and raising the transfer pad to detach the singulated wafer from the chuck table.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a warp generate | occur | produces in plate-shaped objects, such as a semiconductor wafer with which the protective tape was stuck, and can convey a plate-shaped object favorably.

It is a perspective view of the grinding-polishing apparatus of this Embodiment. It is a schematic block diagram of a chuck table mechanism and a conveyance pad, and is an explanatory view of a contact step. It is explanatory drawing of a release on-off valve opening step. It is explanatory drawing of a detachment | leave step.

  Hereinafter, a grinding and polishing apparatus provided with a chuck table mechanism according to the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the grinding and polishing apparatus of the present embodiment. The chuck table mechanism can be applied to a processing apparatus having a chuck table whose holding surface communicates with the suction surface, and is not limited to the grinding and polishing apparatus shown in FIG.

  As shown in FIG. 1, the grinding and polishing apparatus 1 is a full-auto type processing apparatus, which carries in a semiconductor wafer W (hereinafter referred to as “wafer W”), a rough grinding process, a finish grinding process, and a polishing process. A series of operations including processing, cleaning processing, and unloading processing are configured to be performed fully automatically. The wafer W is formed in a substantially disc shape, and is carried into the grinding and polishing apparatus 1 while being accommodated in the cassette CT. The wafer W may be a workpiece made of a plate to be ground and polished, may be a semiconductor substrate such as silicon or gallium arsenide, or may be an inorganic material substrate such as ceramic, glass, or sapphire, Further, it may be a package substrate of a semiconductor product. In the wafer W of the present embodiment, cutting grooves (not shown) having a predetermined depth are formed in a lattice shape on the front side of the wafer W by half-cutting by performing the tip dicing method. A protective tape T (BG (Back Grinding) tape) is stuck on the surface of the wafer W after half-cutting.

  On the front side of the base 11 of the grinding / polishing apparatus 1, a pair of cassettes CT in which a plurality of wafers W are accommodated are placed. Behind the pair of cassettes CT is a cassette robot 16 for taking wafers W in and out of the cassettes CT. A positioning mechanism 21 that positions the unprocessed wafer W and a cleaning mechanism 26 that cleans the processed wafer W are provided on both diagonally rear sides of the cassette robot 16. Between the positioning mechanism 21 and the cleaning mechanism 26, there are provided loading means 31 for loading the unprocessed wafer W onto the chuck table 42 and unloading means 36 for unloading the processed wafer W from the chuck table 42. . The chuck table 42 constitutes a chuck table mechanism 100 (see FIG. 2) described later.

  The cassette robot 16 is configured by providing a hand portion 18 at the tip of a robot arm 17 composed of a multi-node link. In the cassette robot 16, the wafer W before grinding / polishing is transferred from the cassette CT to the positioning mechanism 21, and the wafer W after grinding / polishing is transferred from the cleaning mechanism 26 to the cassette CT. The positioning mechanism 21 is configured by arranging a plurality of positioning pins 23 that can move forward and backward with respect to the center of the temporary table 22 around the temporary table 22. In the positioning mechanism 21, the center of the wafer W is positioned at the center of the temporary placement table 22 by causing a plurality of positioning pins 23 to abut on the outer peripheral edge of the wafer W placed on the temporary placement table 22.

  The carry-in means 31 is configured by providing a carry-in pad 33 at the tip of a carry-in arm 32 that can turn on the base 11. In the carry-in means 31, the wafer W is lifted from the temporary placement table 22 by the carry-in pad 33, and the carry-in pad 33 is turned by the carry-in arm 32 to carry the wafer W into the chuck table 42. The carry-out means 36 is configured by providing a carry-out pad 38 at the tip of a carry-out arm 37 that can turn on the base 11. In the unloading means 36, the wafer W is lifted from the chuck table 42 by the unloading pad 38, and the unloading pad 38 is turned by the unloading arm 37, whereby the wafer W is unloaded from the chuck table 42.

  The cleaning mechanism 26 is configured by providing various nozzles (not shown) that inject cleaning water and dry air toward a spinner table (chuck table) 27. In the cleaning mechanism 26, the spinner table 27 holding the wafer W is lowered into the base 11, cleaning water is sprayed in the base 11 and the wafer W is spinner cleaned, and then dry air is blown to blow the wafer W. Is dried. Behind the carry-in means 31 and the carry-out means 36 is provided a turntable 41 in which four chuck tables 42 are rotatably arranged at equal intervals in the circumferential direction. A holding surface 43 for holding the wafer W is formed on the upper surface of each chuck table 42.

  When the turntable 41 is intermittently rotated at intervals of 90 degrees, the loading / unloading position where the wafer W is loaded and unloaded, the rough grinding position facing the rough grinding means 46, the finish grinding position facing the finish grinding means 51, and the polishing means The polishing position facing 56 is sequentially positioned. At the rough grinding position, the wafer W is roughly ground to a predetermined thickness by the rough grinding means 46. At the finish grinding position, the finish grinding means 51 finish-grinds the wafer W to the finish thickness. At the polishing position, the wafer W is polished by the polishing means 56. Around the turntable 41, columns 12, 13, and 14 are erected.

  The column 12 is provided with a drive mechanism 61 that moves the rough grinding means 46 up and down. The drive mechanism 61 includes a pair of guide rails 62 arranged in front of the column 12 and parallel to the Z-axis direction, and a motor-driven Z-axis slider 63 slidably installed on the pair of guide rails 62. Yes. A rough grinding means 46 is supported on the front surface of the Z-axis slider 63 via a housing 64. A ball screw 65 is screwed onto the back side of the Z-axis slider 63, and a drive motor 66 is connected to one end of the ball screw 65. The ball screw 65 is rotationally driven by the drive motor 66, and the rough grinding means 46 is moved along the guide rail 62 in the Z-axis direction.

  Similarly, the column 13 is provided with a drive mechanism 71 for moving the finish grinding means 51 up and down. The drive mechanism 71 includes a pair of guide rails 72 arranged in front of the column 13 and parallel to the Z-axis direction, and a motor-driven Z-axis slider 73 slidably installed on the pair of guide rails 72. Yes. A finish grinding means 51 is supported on the front surface of the Z-axis slider 73 via a housing 74. A ball screw 75 is screwed to the back side of the Z-axis slider 73, and a drive motor 76 is connected to one end of the ball screw 75. The ball screw 75 is rotationally driven by the drive motor 76, and the finish grinding means 51 is moved along the guide rail 72 in the Z-axis direction.

  A mount 48 is provided at the lower end of the spindle 47 of the rough grinding means 46, and a rough grinding wheel 49 in which a plurality of rough grinding wheels 50 are annularly arranged is mounted on the lower surface of the mount 48. The rough grinding wheel 50 is composed of, for example, a diamond grinding stone in which diamond abrasive grains are hardened with a binder such as a metal bond or a resin bond. Further, a mount 53 is provided at the lower end of the spindle 52 of the finish grinding means 51, and a finish grinding grinding wheel 54 in which a plurality of finish grinding wheels 55 are annularly arranged is mounted on the lower surface of the mount 53. The finish grinding wheel 55 is composed of abrasive grains having a smaller particle diameter than the coarse grinding wheel 50.

  The column 14 is provided with a drive mechanism 81 for positioning the polishing means 56 at a predetermined polishing position with respect to the wafer W. The drive mechanism 81 includes a pair of guide rails 82 arranged in front of the column 14 and parallel to the Y-axis direction, and a motor-driven Y-axis slider 83 slidably installed on the pair of guide rails 82. Yes. The drive mechanism 81 includes a pair of guide rails 84 arranged in front of the Y-axis slider 83 and parallel to the Z-axis direction, and a motor-driven Z-axis slider 85 slidably installed on the pair of guide rails 84. have. A polishing means 56 is supported on the front surface of the Z-axis slider 85 via a housing 86.

  A ball screw (not shown) is screwed to the back side of the Y-axis slider 83 and the Z-axis slider 85, and drive motors 87 and 88 are connected to one end of the ball screw. The ball screw is rotationally driven by the drive motors 87 and 88, and the polishing means 56 is moved along the guide rails 82 and 84 in the Y-axis direction and the Z-axis direction. A mount 94 is provided at the lower end of the spindle 93 of the polishing means 56, and a polishing pad 95 made of foam or fiber is attached to the lower surface of the mount 94. By grinding the wafer W with the polishing pad 95, the grinding damage left on the wafer W is removed.

  In such a grinding and polishing apparatus 1, the wafer W is transferred from the cassette CT to the positioning mechanism 21, and the wafer W is centered by the positioning mechanism 21. Next, the wafer W is loaded onto the chuck table 42, and the wafer W is positioned in the order of the rough grinding position, the finish grinding position, and the polishing position by the rotation of the turntable 41. The back surface of the wafer W is roughly ground at the rough grinding position, and the back surface of the wafer W is finish ground at the finish grinding position, and the wafer W is thinned to a predetermined finish thickness by these grinding operations. As a result of this thinning, a cutting groove by the front dicing method appears on the back surface of the wafer W, and the wafer W is divided into individual semiconductor chips C to become individual wafers Wa (see FIG. 2). After the rough grinding process and the finish grinding process, the individual wafer Wa is polished at the polishing position. Then, after the singulated wafer Wa is transferred from the chuck table 42 to the spinner table 27, the singulated wafer Wa is cleaned by the cleaning mechanism 26 and is cleaned into the cassette CT from the cleaning mechanism 26. Wafer Wa is unloaded.

  Next, the chuck table mechanism and the transport pad of the present embodiment will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the chuck table mechanism and the transport pad. As shown in FIG. 2, the chuck table mechanism 100 according to the present embodiment includes the chuck table 42 described above. The chuck table mechanism 100 includes four chuck tables 42 (see FIG. 1). Since each chuck table 42 has the same configuration, one chuck table 42 is illustrated and described. The chuck table 42 includes a porous member 42a that forms an upper surface of the chuck table 42. The porous member 42a is made of porous ceramics having numerous suction holes. The porous member 42 a forms a holding surface 43 for sucking and holding the wafer W on the upper surface of the chuck table 42. The chuck table 42 is formed with a communication path 42 b that communicates with the holding surface 43.

  In the chuck table mechanism 100 of the present embodiment, a suction source 102 is communicated with the communication path 42b via the suction path 101. Further, a blow fluid supply source (blow fluid) 104 is connected to the suction passage 101 via a blow fluid supply passage 103. In other words, the blow fluid is connected to the communication passage 42b via the suction passage 101 and the blow fluid supply passage 103. A source 104 is connected. A first electromagnetic opening / closing valve 105 is disposed in the vicinity of the suction source 102 of the suction passage 101, and a second electromagnetic opening / closing valve 106 is disposed in the blow fluid supply passage 103. When the first electromagnetic opening / closing valve 105 is opened, a suction force is applied to the protective tape T that the suction source 102 communicates with the holding surface 43 through the suction passage 101 and the communication passage 42 b and contacts the holding surface 43. When the second electromagnetic opening / closing valve 106 is opened, the blow fluid is supplied from the blow fluid supply source 104 to the holding surface 43 through the blow fluid supply passage 103, the suction passage 101, and the communication passage 42b, and the suction on the holding surface 43 is released. . An example of the blow fluid is a mixed fluid of compressed air and water.

  In the suction passage 101, pressure detecting means 107 is disposed in the vicinity of the communication passage 42b, and the pressure detecting means 107 detects the pressure in the suction passage 101. A release path 108 is provided by branching between the pressure detection means 107 of the suction passage 101 and the first electromagnetic on-off valve 105. A release opening / closing valve 109 is disposed in the release path 108, and the release path 108 is opened to the atmosphere by opening the release opening / closing valve 109. Then, the suction passage 101 and the communication passage 42b, which become negative pressure due to the air release, can be increased in pressure.

  Further, the chuck table mechanism 100 according to the present embodiment controls the first electromagnetic on-off valve 105, the second electromagnetic on-off valve 106, and the release on-off valve 109 based on a detection signal from the pressure detection means 107. It has. The control unit 111 includes a processor that executes various processes, a memory, and the like. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application. Although not described here, each of the four chuck tables 42 is connected to the suction source 102 and the blow fluid supply source 104 via valves and passages in the same manner as described above, and the holding surface 43 is controlled by the control means 111. The suction at is controlled.

  On the holding surface 43 of the chuck table 42, the separated wafer Wa is sucked and held via the protective tape T. Transfer (unload) of the singulated wafer Wa from the holding surface 43 of the chuck table 42 is performed by a transfer pad 38. A suction holding surface 38a is formed on the lower surface of the transfer pad 38, and the suction holding surface 38a is formed to have a diameter corresponding to the outer diameter of the singulated wafer Wa or the wafer W (see FIG. 1). A communication path (not shown) that communicates with the suction holding surface 38a is formed in the transport pad 38, and a suction source 38c communicates with the communication path via a suction path 38b. The suction passage 38b is provided with a transport pad electromagnetic valve 38d. When the singulated wafer Wa is transferred from the holding surface 43 of the chuck table 42, the suction holding surface 38a of the transfer pad 38 is brought into contact with the upper surface (back surface) of the singulated wafer Wa. In this abutted state, the transfer pad electromagnetic valve 38d is operated to open, and the suction source 38c is communicated with the suction holding surface 38a, whereby the singulated wafer Wa is sucked and held by the suction holding surface 38a. (See FIG. 4).

  By the way, the protective tape T is attached to the wafer W before grinding (see FIG. 1), but the attachment conditions are various, and the occurrence of wrinkles on the protective tape T during the attachment In order to prevent air bubbles from being mixed, the protective tape T is often applied while applying an application tension (tension). Accordingly, a sticking tension remains on the protective tape T, and this sticking tension acts in a direction that causes the wafer W to warp. However, since the wafer W before grinding is thick, even if sticking tension remains on the protective tape T, the warp is suppressed by the rigidity of the wafer W and chucked from the cassette CT (both see FIG. 1) by the transfer pad 33. The table 42 can be conveyed. On the other hand, the separated wafer Wa made of the separated semiconductor chips C is divided into a plurality of pieces, so that the force against the sticking tension of the protective tape T cannot be exhibited. For this reason, the chuck table 42 is sucked and held with a relatively high suction force so that the smoothness of the singulated wafer Wa and the protective tape T can be maintained even when sucked and held by the holding surface 43 via the protective tape T. The

  Here, in the conventional transfer method of the singulated wafer Wa to which the protective tape T is stuck, the singulated wafer Wa is sucked by the suction holding surface 38a of the transfer pad 38 with a relatively weak suction force. After the holding, the suction holding by the chuck table 42 is released instantaneously. For this reason, the sticking tension of the protective tape T, which has been maintained smooth with a high suction force by the holding surface 43, is not instantly regulated and easily contracts greatly. As a result, warpage of the separated wafer Wa to which the protective tape T is stuck increases, and the wafer Wa falls away from the suction holding surface 38a of the transfer pad 38, or a transfer error occurs.

  Therefore, in the present embodiment, paying attention to the fact that the warp of the protective tape T is increased when the suction holding is released by the chuck table 42 instantaneously, the releasing of the suction holding is described below. Release in stages. As a result, the warped state of the protective tape T can be suppressed and the state where the individual wafer Wa is in contact with the suction holding surface 38a of the transport pad 38 can be maintained well, and the individual wafer Wa is dropped from the transport pad 38. It can be transported without doing.

  Hereinafter, with reference to FIG. 3 and FIG. 4 in addition to FIG. 2, the flow of the method for transporting the singulated wafer Wa according to the present embodiment will be described. 2 to 4 are explanatory diagrams of steps in the transport method according to the present embodiment. FIG. 2 is an explanatory diagram of the contact step, FIG. 3 is an explanatory diagram of the release on / off valve opening step, and FIG. 4 is an explanatory diagram of the release step. Note that the steps shown in FIGS. 2 to 4 are merely examples, and the present invention is not limited to this configuration.

  As shown in FIG. 2, a contact step is first performed. Here, it is assumed that the singulated wafer Wa is sucked and held via the protective tape T by the holding surface 43 of the chuck table 42. Specifically, the first electromagnetic on-off valve 105 is opened with the second electromagnetic on-off valve 106 and the release on-off valve 109 closed, and the holding surface 43 and the suction source 102 communicate with each other to hold the holding surface. A protective tape T that abuts against the nozzle 43 is sucked and held. In this state, in the contact step, the transport pad 38 is moved to bring the suction holding surface 38a into contact with the upper surface (back surface) of the singulated wafer Wa.

  As shown in FIG. 3, after performing the contact step, a release opening / closing valve opening step is performed. In the release opening / closing valve opening step, the release opening / closing valve 109 is opened from the state shown in FIG. 2 to release the release path 108 to the atmosphere. By this release, external air flows from the release opening / closing valve 109 into the suction passage 101 through the release passage 108 to weaken the negative pressure of the suction passage 101 and the communication passage 42b, and the protective tape adhered to the singulated wafer Wa. The suction force for sucking and holding T is reduced. In the reduction of the suction force, the air in the suction passage 101 is sucked by the suction source 102 and the outside air flows in by the opening of the release opening / closing valve 109, so that the pressure in the suction passage 101 rises relatively slowly. . Thereby, the sticking tension of the protective tape T can be gradually released.

  In the release opening / closing valve opening step, the control means 111 compares the pressure value in the suction passage 101 as a detection signal detected by the pressure detection means 107 with a predetermined threshold value, and the release opening / closing valve until the pressure value rises above the threshold value. The 109 opening is continued. In the release opening / closing valve opening step, instead of continuing the opening of the release opening / closing valve 109, the suction force may be reduced by controlling the opening / closing intermittently a plurality of times.

  As shown in FIG. 4, after performing the release on / off valve opening step, the separation step is performed. In the detachment step, when the pressure value in the suction passage 101 detected by the pressure detecting means 107 is increased by the control means 111 from the above threshold value, the first electromagnetic on-off valve 105 and the second electromagnetic on-off opening from the state shown in FIG. The valve 106 and the release opening / closing valve 109 are operated. Specifically, the first electromagnetic on-off valve 105 is closed and the supply of the suction force from the suction source 102 is stopped. Further, the release on-off valve 109 is closed to restrict external air from flowing into the suction passage 101. Further, the second electromagnetic on-off valve 106 is opened, the blow fluid is supplied from the blow fluid supply source 104 to the suction passage 101, the pressure in the suction passage 101 is increased, and the suction force by the holding surface 43 is released.

  Thereafter, the conveyance pad electromagnetic valve 38d is opened to connect the suction source 38c to the suction holding surface 38a. Accordingly, a suction force is applied to the individual wafer Wa that is in contact with the suction holding surface 38a of the transfer pad 38, and the individual wafer Wa is sucked and held on the suction holding surface 38a. After the suction and holding, the wafer pad Wa is separated from the chuck table 42 by raising the transfer pad 38.

  As described above, in the conveyance using the chuck table mechanism 100 of the present embodiment, the suction by the suction source 102 to the suction passage 101 is continued until the pressure value detected by the pressure detection means 107 rises to a predetermined threshold value. Atmospheric release is performed at the same time. Thereafter, when the pressure value detected by the pressure detection means 107 rises to a predetermined threshold value, the blow fluid is supplied and the suction holding is released. Accordingly, the suction force of the chuck table 42 can be reduced stepwise without instantaneously decreasing, and the sticking tension remaining on the protective tape T can also be released stepwise. Thereby, it is possible to suppress the warping of the singulated wafer Wa to which the protective tape T is adhered in the separation step, and the protective tape T is partially separated from the suction holding surface 38a of the transfer pad 38 so that the suction force is increased. It can be avoided that it does not work sufficiently. As a result, the suction force at the transport pad 38 is stably applied, and it is possible to prevent the separated wafer Wa from dropping or causing a transport error to be transported to an unintended position. it can.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, direction, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, the chuck table constituting the chuck table mechanism 100 is not limited to the chuck table 42 that sucks and holds the wafer W to be processed when grinding or polishing, but is changed to the spinner table 27 or the like of the cleaning mechanism 26. May be. In this case, the spinner table 27 is configured in the same manner as the chuck table 42 shown in FIG. 2, and the cleaned wafer Wa is transferred to a transfer device or the like by a transfer pad.

  As described above, the present invention has the effect of being able to satisfactorily transport a plate-like object such as a semiconductor wafer to which a protective tape is attached, and in particular, has been separated from the holding surface of the chuck table. This is useful for a transfer method for transferring a wafer.

38 Transport pad 38a Suction holding surface 42 Chuck table 43 Holding surface 100 Chuck table mechanism 101 Suction passage 102 Suction source 103 Blow fluid supply passage 104 Blow fluid supply source (blow fluid)
DESCRIPTION OF SYMBOLS 105 1st electromagnetic on-off valve 106 2nd electromagnetic on-off valve 107 Pressure detection means 108 Release path 109 Release on-off valve 111 Control means C Semiconductor chip T Protection tape W Wafer (plate-shaped member, semiconductor wafer)
Wa Individual wafers

Claims (2)

A chuck table provided with a holding surface for sucking and holding the plate-like object through the protective tape of the plate-like object attached with a protective tape, and a communication path communicating with the holding surface;
A suction source connected to the communication path via a suction path;
A first electromagnetic on-off valve disposed near the suction source of the suction passage;
A blow fluid connected to the communication passage through a blow fluid supply passage;
A chuck table mechanism comprising: a second electromagnetic on-off valve disposed in the blow fluid supply passage;
Pressure detecting means disposed in the suction passage in the vicinity of the communication passage for detecting the pressure in the suction passage;
A release path branched between the pressure detecting means of the suction passage and the first electromagnetic on-off valve and released to the atmosphere via the release on-off valve;
Control means for controlling the first electromagnetic on-off valve, the second electromagnetic on-off valve and the release on-off valve based on a detection signal from the pressure detection means,
When releasing the suction holding of the plate-like object sucked and held by the chuck table, the control means controls the opening and closing of the release on-off valve, and when the detection signal from the pressure detecting means rises to a predetermined value, A chuck table mechanism that closes the first electromagnetic on-off valve and opens the second electromagnetic on-off valve. After half-cutting the front side of the semiconductor wafer, a protective tape is attached to the front side, and backside grinding is performed to divide the semiconductor wafer into individual semiconductor chips. A chucking method for transporting a singulated wafer from the chuck table holding surface of the chuck table mechanism according to claim 1,
Contacting the suction holding surface of the transfer pad having a suction holding surface corresponding to the outer diameter of the semiconductor wafer with the upper surface of the singulated wafer;
Release opening and closing that controls the opening and closing of the release on-off valve of the chuck table mechanism to reduce the suction force for sucking and holding the protection tape attached to the singulated wafer and releasing the attachment tension of the protection tape A valve opening step;
After the carrying pad contact step and the release on / off valve opening step, when the detection signal from the pressure detecting means rises to a predetermined value, the first electromagnetic on / off valve is closed and the second electromagnetic on / off valve is closed. A separation step of applying a suction force to the singulated wafer that is in contact with the transfer pad and lifting the transfer pad to detach the singulated wafer from the chuck table;
Conveying method including.

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