JP2010056327A - Work holding mechanism - Google Patents

Abstract

A workpiece such as a wafer wet with a grinding fluid is transported to a cleaning means without being dried for easy cleaning.
Three holding members 81 arranged below a disk-like support plate 91 are movably supported along long holes 92 formed radially on the support plate 91, and each holding member 81 is moved. Move by 100. Each holding member 81 is positioned around the work 9 on the chuck table 30 in a state where the holding member 81 is spread to the outer peripheral side. After the work 9 is lifted, each holding member 81 is moved to the inner peripheral side, and the work is moved to the engagement recess 82. The outer peripheral edge of 9 is fitted and held. While supplying water from the tube 130 to the upper surface of the wafer 1, the arm 72 is rotated, and the work 9 is conveyed to the spinner type cleaning device 60.
[Selection] Figure 11

Description

  The present invention relates to a work holding mechanism for holding and transporting a disk-shaped work such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a large number of rectangular areas are defined on the surface of a disk-shaped semiconductor wafer (hereinafter referred to as a wafer) by grid-like division lines, and electronic circuits such as ICs and LSIs are formed on the surface of these rectangular areas. After the formation, all the dividing lines are cut, that is, diced to obtain a large number of semiconductor chips from one wafer. The semiconductor chip thus obtained is packaged by resin sealing and widely used in various electric / electronic devices such as mobile phones and PCs (personal computers).

  In such a manufacturing process, prior to dicing into a large number of semiconductor chips, the back surface opposite to the surface on which the electronic circuit is formed is ground and thinned to a predetermined thickness. Thinning of the wafer is performed for the purpose of further reducing the size and weight of the equipment and improving heat dissipation. For example, the thickness of the wafer is reduced from about 700 μm to about 50 to 100 μm. It is done.

  As a grinding device for grinding the back surface of a wafer, a storage cassette for storing a large number of pre-grinding wafers, a pre-grinding wafer taken out from the storage cassette is temporarily placed, and a transfer system is positioned. Temporary placement table, chuck table for holding the wafer transferred from the temporary placement table in a state where the back surface is exposed, grinding means such as a grinder for grinding the back surface of the wafer held on the chuck table, and the back ground wafer is the chuck table It is known that there are a cleaning section for transferring a wafer and a cassette for storing a wafer cleaned by the cleaning section (see Patent Documents 1 and 2).

  The wafers are transported according to the order of the processes. However, in the grinding apparatus described in Patent Documents 1 and 2, the wafer is transferred from the temporary placement table to the chuck table and the wafer from the chuck table to the cleaning unit. Is transferred by a transfer means equipped with a vacuum suction type wafer holding mechanism. The transfer means transfers a wafer by turning an arm having a wafer holding mechanism at the tip. The wafer holding mechanism performs a vacuum operation in which air is sucked from the suction surface of the suction pad facing downward, sucks and holds the wafer on the suction surface, and stops the vacuum operation to detach the wafer from the suction pad.

JP 2004-91196 A JP 2006-344778 A

  In the vacuum suction type wafer holding mechanism, the suction surface of the suction pad sucks air and holds the wafer while sucking air. For this reason, when there is moisture on the back surface of the wafer, the moisture is sucked and dried. In fact, during backside grinding, the grinding liquid is supplied to the backside of the wafer. Therefore, when the wafer after backside grinding is held by the wafer holding mechanism and taken up, the backside of the wafer is wet with the grinding liquid. However, when being transported to the cleaning section, the grinding liquid is sucked and dried.

  The grinding liquid remaining on the back surface of the wafer is contaminated with powdered grinding dust and the like generated by back surface grinding, and the cleaning unit is to remove the contamination. However, when the back surface of the wafer dries due to the suction pad of the wafer holding mechanism being sucked, there is a problem that even if the back surface is cleaned by the cleaning unit, the dirt is not easily removed and the wafer is not sufficiently cleaned.

  The present invention has been made in view of the above circumstances, and can transport a workpiece such as a wafer wet with a grinding fluid to a target location without drying, thereby sufficiently, for example, supporting the workpiece. An object of the present invention is to provide a work holding mechanism capable of accurately obtaining the effect of not being dried, such as being able to be washed.

  The workpiece holding mechanism of the present invention is positioned to face three or more holding members that hold the outer peripheral edge of a disk-shaped workpiece, and the workpiece that holds the outer peripheral edge by the holding member, and radiates the holding member. A guide plate that guides in the direction, a support plate that movably supports the holding member along the guide portion, a moving means that moves the holding member along the guide portion, and a workpiece held by the holding member. It is characterized by comprising at least water supply means for supplying water to the surface facing the support plate.

  According to the present invention, since the work is held at the outer peripheral edge by the holding member, unlike the conventional work holding mechanism using the suction pad, both surfaces are held in an exposed state. And by supplying water from a water supply means, a workpiece | work can always be conveyed in the state wet with water, and it can prevent drying. Therefore, if the work holding mechanism of the present invention is applied to the transport mechanism that transports the wafer from the chuck table to the cleaning unit in the above-described grinding processing apparatus, it is difficult for the dirt to be removed by drying. The effect that it can wash | clean sufficiently is acquired.

The following forms are mentioned about the concrete structure of this invention.
The guide portion is formed by a long hole formed in the support plate and extending in the radial direction, and the holding member includes an engagement portion having an engagement concave portion that engages with an outer peripheral edge of the workpiece, and the engagement portion. And a guided support portion that is inserted through the long hole.

  The holding member is formed between the work plate and the support plate, which is continuous with the engagement recess and has an outer peripheral edge engaged with the engagement recess, and guides the outer periphery of the work to the engagement recess. It has a tapered workpiece receiving surface.

  Further, the moving means is provided for each holding member and a rotating plate that is rotatably attached to a substantially center of the support plate via a rotating shaft, and has one end portion on the holding member and the other end portion. Is provided with a link rotatably connected to the rotation plate, and a rotation drive means for rotating the rotation plate.

  The work holding mechanism of the present invention includes a usage method in which a work placed on a predetermined placement surface is held by the holding member. In this case, a plurality of spacer pins are provided on the surface of the support plate facing the work held by the holding member so as to ensure a certain distance between the facing surface and the mounting surface. Form is preferred. That is, in this embodiment, the spacer pin abuts on the placement surface, so that the placement surface and the support plate become parallel, and the spacer pin restricts the workpiece from moving in the direction parallel to the placement surface. Therefore, it is easy to guide and hold the workpiece on the holding member. Further, the holding member is prevented from coming into contact with the mounting surface, and the holding member is prevented from being damaged.

  The work referred to in the present invention is not particularly limited, but examples include the above-described semiconductor wafers such as silicon wafers, and various processing materials that require micron-order accuracy such as ceramics, glass, sapphire, and silicon-based substrates. It is done.

  According to the present invention, since the outer peripheral edge of the disk-shaped workpiece can be held by the holding member and water can be supplied to the workpiece by the water supply means, the workpiece such as a wafer can be transported without drying. Thus, for example, it is possible to adequately obtain the effect of not being dried, for example, the work can be sufficiently washed.

Hereinafter, a wafer grinding apparatus to which a workpiece holding mechanism according to the present invention is applied will be described with reference to the drawings.
[1] Semiconductor Wafer First, a semiconductor wafer according to an embodiment shown in FIG. 1 will be described. The semiconductor wafer 1 (hereinafter referred to as wafer 1) is a silicon wafer or the like, and has a thickness before processing of, for example, about 700 μm. A plurality of rectangular chips 3 are partitioned on the front surface of the wafer 1 (in FIG. 1, the back surface side of the wafer 1 is on the upper side) by a grid-like division planned line 2. Electronic circuits (not shown) such as ICs and LSIs are formed on the surfaces of these chips 3. A V-shaped notch 4 indicating a semiconductor crystal orientation is formed at a predetermined location on the peripheral surface of the wafer 1.

  The back surface of the wafer 1 is ground by the wafer grinding apparatus 10 shown in FIG. 2 and thinned to a thickness of about 50 to 100 μm, for example. As shown in FIG. 1, a wafer 1 to be provided to the wafer grinding apparatus 10 is as shown in FIG. 1 in order to be able to reliably hold and transport the thinned wafer 1 with reduced rigidity by the work holding mechanism of this embodiment. The substrate 5 is adhered to the surface (the lower surface in FIG. 1). The substrate 5 is made of, for example, silicon or glass, which is a material of a semiconductor wafer, and is formed in a disk shape having an outer diameter similar to that of the wafer 1 and having a thickness that does not cause bending. And is attached to the surface of the wafer 1 with an appropriate adhesive. By attaching the substrate 5, the wafer 1 is maintained in a flat state without being bent even if the wafer 1 is ground and thinned, and can be transferred in that state. In the following description, what the substrate 5 is bonded to the wafer 1 shown in FIG. 1 is referred to as a workpiece 9 which is a conveyance object in the present embodiment.

[2] Wafer Grinding Device The wafer grinding device 10 shown in FIG. 2 sucks and holds the workpiece 9 on a vacuum suction chuck table 30 and holds two grinding units (for rough grinding and for finishing grinding). Rough grinding and finish grinding are sequentially performed on the back surface of the wafer 1 by 40A and 40B. Hereinafter, the configuration and operation of the apparatus 10 will be described.

  Reference numeral 11 in FIG. 2 denotes a processing stage for grinding the wafer 1, and a workpiece 9 having the wafer 1 before grinding is supplied to the processing stage 11 on the front side in the Y direction of the processing stage 11, and A supply / recovery stage 12 for recovering the workpiece 9 including the wafer 1 after grinding is also provided.

  Two elevators 13A and 13B arranged in the X direction are installed at the end of the supply / collection stage 12 on the front side in the Y direction. Among these elevators 13A and 13B, the supply cassette 14A for storing a plurality of workpieces 9 including the wafer 1 before back surface grinding is set in the elevator 13A on the front side in the X direction. Further, in the elevator 13B on the back side in the X direction, a collection cassette 14B for storing a plurality of workpieces 9 including the wafer 1 after back grinding is set. These cassettes 14A and 14B have the same configuration and are provided with trays for storing the workpieces 9 one by one in a stacked state.

  The workpiece 9 accommodated in the supply cassette 14A is positioned at a predetermined removal height position by raising and lowering the elevator 13A. The workpiece 9 is taken out from the supply cassette 14A by the transfer robot 15 and temporarily placed on the temporary placement table 16 provided on the supply / recovery stage 12 with the back surface of the wafer 1 facing upward. The The workpiece 9 placed on the temporary placement table 16 is positioned at a certain transfer start position.

  A turntable 17 that is rotationally driven in the R direction is provided on the processing stage 11. A plurality of (in this case, three) disk-shaped chuck tables 30 are arranged on the outer peripheral portion of the turntable 17 at equal intervals in the circumferential direction. As shown in FIG. 7, the chuck table 30 has a suction portion 32 made of a porous material fitted on the upper surface of a frame 31, and sucks the air above the suction portion 32 when operated in a vacuum. The workpiece 9 is sucked and held on the horizontal upper surface (mounting surface) 32a of the suction portion 32. In contrast to the vacuum operation, the suction unit 32 is also supplied with air and blows air upward from the suction unit 32. Each chuck table 30 is rotatably supported by the turntable 17 and is rotated in one direction or both directions by a rotation driving mechanism (not shown).

  The workpiece 9 positioned on the temporary placement table 16 is picked up from the temporary placement table 16 by the supply means 20 and conveyed to above the one chuck table 30 in the vacuum operation state positioned at the workpiece attachment / detachment position. The workpiece 9 is placed concentrically on the chuck table 30 with the back surface of the wafer 1 facing upward. The workpiece attachment / detachment position in this case is a position where the chuck table 30 is closest to the supply / collection stage 12, and the chuck table 30 is positioned at the workpiece attachment / detachment position by the rotation of the turntable 17. The supply means 20 is provided at a position of the supply / recovery stage 12 close to the workpiece attaching / detaching position.

  The supply means 20 has a horizontally extending arm 22 fixed to a rotary shaft 21 extending in the Z direction that is rotatable and vertically movable, and a vacuum suction type suction pad 23 is attached to the tip of the arm 22. It is provided. According to this supply means 20, the suction shaft 23 is positioned above the work 9 on the temporary placement table 16 by rotating the rotary shaft 21 and turning the arm 22, and then the rotary shaft 21 is lowered and moved downward. By performing a vacuum operation in which air is sucked from the suction surface of the suction pad 23 facing, the work 9 is sucked and held on the suction surface. When the workpiece 9 on the temporary placement table 16 is held by the suction pad 23, the rotary shaft 21 is raised, the arm 22 is turned, and the workpiece 9 is conveyed to the workpiece attaching / detaching position, where the rotary shaft 21 is lowered, The vacuum operation is stopped. As a result, the workpiece 9 is placed on the chuck table 30 that is operated in vacuum.

  The work 9 held on the chuck table 30 is fed to a primary processing position below the rough grinding grinding unit 40A when the turntable 17 rotates by a predetermined angle in the R direction. At this position, the wafer 9 is fed by the grinding unit 40A. The back surface of 1 is roughly ground. Next, the work 9 is again fed to the secondary machining position below the finish grinding grinding unit 40B by rotating the turntable 17 a predetermined angle in the R direction. At this position, the back surface of the wafer 1 is moved by the grinding unit 40B. Finished grinding.

  Two columns 50A and 50B arranged in the X direction are erected at the end of the processing stage 11 on the back side in the Y direction, and the grinding units 40A and 40B are respectively Z in front of the columns 50A and 50B. It can be moved up and down in the direction (vertical direction). Each grinding unit 40A, 40B is slidably mounted via a slider 52 on a guide 51 extending in the Z direction provided on the front surface of each column 50A, 50B, and is driven by a servo motor 53. The feed mechanism 54 moves up and down in the Z direction via the slider 52.

  Each of the grinding units 40A and 40B has the same configuration, and is distinguished by the fact that the grindstones to be mounted are different for rough grinding and finish grinding. The grinding units 40A and 40B have a cylindrical spindle housing 41 whose axial direction extends in the Z direction, and a spindle shaft (not shown) that is rotationally driven by a spindle motor 42 is supported in the spindle housing 41. ing. A grindstone wheel 44 is attached to the lower end of the spindle shaft via a flange 43.

  On the lower surface of the grindstone wheel 44, a plurality of grindstones 45 are arranged in an annular shape. The grinding surface formed by the lower surfaces of these grinding wheels 45 is set to be horizontal and orthogonal to the axial direction of the spindle shaft. Therefore, the ground surface is parallel to the upper surface of the chuck table 30. As the grindstone 45, for example, a glass-bonded material mixed with diamond abrasive grains, molded, and sintered is used.

  As the grindstone 45 attached to the grinding unit 40A for rough grinding, for example, a grindstone containing relatively coarse abrasive grains of about # 330 to # 400 is used. Further, as the grindstone 45 attached to the grinding unit 40B for finish grinding, for example, a grindstone containing relatively fine abrasive grains of about # 3000 to # 8000 is used. Each of the grinding units 40A and 40B is provided with a grinding water supply mechanism (not shown) for supplying grinding water for cooling and lubrication of the surface to be ground or discharging grinding waste.

  The grindstone wheel 44 rotates integrally with the spindle shaft, and the grinding outer diameter of the rotating grindstone 45 is set larger than the diameter of the wafer 1. Further, the processing position of the wafer 1 determined by rotating the turntable 17 by a predetermined angle is that the cutting edge, which is the lower surface of the grindstone 45, passes through the rotation center of the wafer 1 and the wafer 1 that rotates as the chuck table 30 rotates. It is set at a position where the entire back surface can be ground.

  The back surface of the wafer 1 is ground by each grinding unit 40A, 40B at each processing position of rough grinding and finish grinding. In the backside grinding, the chuck table 30 rotates to rotate the workpiece 9, and the grindstone 45 of the rotating grindstone wheel 44 is exposed on the wafer 1 while the feed unit 54 feeds the grinding unit 40 </ b> A (40 </ b> B) downward. This is done by pressing against the back side.

  The wafer 1 is thinned to a target thickness through rough grinding and finish grinding, and the thickness is measured by a thickness measurement gauge (not shown) provided near each processing position. The back surface grinding of the wafer 1 is performed while measuring the thickness of the wafer 1 with the thickness measurement gauge, and the feed amount of the grinding wheel 44 by the feed mechanism 54 is controlled based on the measured value. In rough grinding, the target thickness after finish grinding is ground to, for example, 30 to 40 μm, and the rest is ground by finish grinding.

  When the wafer 1 has been thinned to the target thickness through rough grinding and finish grinding, the workpiece 9 is collected as follows. First, the finish grinding unit 40B is raised and retracted from the wafer 1, and then the turntable 17 is rotated by a predetermined angle in the R direction, whereby the work 9 is returned to the work attaching / detaching position. Next, the vacuum operation of the chuck table 30 is stopped, and then the workpiece 9 is transferred to the spinner type cleaning device 60 by the recovery means 70 provided in the supply / recovery stage 12.

  In the spinner type cleaning device 60, the cleaning water is supplied to the wafer 1 of the work 9 held and rotated by the vacuum suction type spinner table 61 to clean the wafer 1, and then the cleaning water is kept rotating while the spinner table 61 is rotated. Is stopped and the wafer 1 is dried. The spinner table 61 has the same configuration as that of the chuck table 30 and includes a frame body 62 and a suction portion 63 made of a porous material having an upper surface 63a as the suction surface of the workpiece 9, as shown in FIG. It is rotated at a predetermined speed by a rotation drive mechanism (not shown).

  The above steps are continuously repeated for the workpiece 9 in the supply cassette 14A, and a plurality of workpieces 9 whose back surface is ground and thinned to the target thickness are stored in the recovery cassette 14B. The Thereafter, the workpiece 9 including the thinned wafer 1 is transported to the next step together with the collection cassette 14B, and finally the substrate 5 is peeled off, and then the division planned line 2 of the wafer 1 is cut. Dicing into a plurality of chips 3 is performed.

[3] Recovery means The recovery means 70 includes a work holding mechanism 80 according to the present invention, and the recovery means 70 will be described in detail below.
As shown in FIG. 2, the recovery means 70 is disposed adjacent to the back side in the X direction of the supply means 20, and is similar to the supply means 20. A horizontal arm 72 fixed to the shaft 71 is provided. The distal end of the arm 72 is bent downward at a right angle, and a flange 73 is provided at the distal end. A workpiece holding mechanism 80 is attached to the flange 73.

  As shown in FIGS. 3 to 5, the work holding mechanism 80 supports a plurality of (in this case, three) holding members 81 that hold the outer peripheral edge of the work 9, and these holding members 81 are movable in the radial direction. A support plate 91 is provided. As shown in FIGS. 4 and 5, the holding member 81 has a pulley shape in which an engagement concave portion 82 having a substantially V-shaped cross section is formed on the entire outer peripheral surface of the conical member whose diameter decreases toward the lower side. The engaging portion 83 includes a cylindrical shaft portion (guided support portion) 84 that protrudes from the center of the upper surface of the engaging portion 83 and extends upward.

  As shown in FIG. 5, the outer peripheral surface of the engaging portion 83 has conical tapered surfaces 82 a and 82 b formed above and below the peripheral groove-shaped engaging recess 82, respectively. In this case, the upper tapered surface (work receiving surface) 82a has a larger diameter than the lower tapered surface 82b and protrudes to the outer peripheral side. On the other hand, the shaft portion 84 is formed with a screw hole 84a that opens upward. The holding member 81 is made of a low friction material such as a fluororesin.

  The support plate 91 has a disk shape having an outer diameter larger than that of the work 9, and a plurality of (in this case, three) long holes 92 extending in the radial direction (radial direction) are formed in the outer peripheral portion. The shaft portion 84 of the holding member 81 is inserted into the long holes 92 from below so as to be movable along the long holes 92. Further, a stepped nut (rotating shaft) 93 having a large diameter portion 93a and a small diameter portion 93b at the center of the upper surface of the support plate 91 and having a screw hole 93c formed through the center is fixed concentrically. . The engaging portion 83 of the holding member 81 is disposed on the lower side of the support plate 91, and the upper tapered surface 82a is inclined so as to approach the upper support plate 91 toward the outer peripheral side.

  The holding member 81 is reciprocated along the long hole 92 by the moving means 100 provided on the support plate 91. The moving unit 100 includes a rotating plate 101, a link 110, and an air cylinder (rotating driving unit) 120. The rotating plate 101 is mainly composed of a disc portion 102, and a plurality of (in this case, three) arm portions 103 extending in the radial direction are arranged at equal intervals in the circumferential direction on the outer peripheral edge of the disc portion 102. Formed. In addition, an arc hole 104 is formed along the circumferential direction at a portion of the outer peripheral portion of the disc portion 102 that hits between the arm portions 103. A hole 105 is formed in the center of the disc portion 102, and this hole 105 is rotatably fitted in the small diameter portion 93 b of the stepped nut 93. The stepped nut 93 is screwed with a screw 94 that prevents the rotation plate 101 from coming off.

  The link 110 is a straight plate-like member, and normally extends along the radial direction of the support plate 91. Holes 111 and 112 are provided at one end on the outer peripheral side and the other end on the inner peripheral side, respectively. Is formed. The hole 111 on the outer peripheral side is rotatably fitted into the shaft portion 84 of the holding member 81 that is inserted through the long hole 92 and protrudes upward, and the screw 113 is screwed into the screw hole 84a of the shaft portion 84. It is. Before the hole 111 is fitted into the shaft portion 84, the washer 114 is fitted into the shaft portion 84. On the other hand, the hole 112 on the inner peripheral side of the link 110 is rotatably fitted into a pin 115 inserted through a hole 103 a formed at the tip of the arm portion 103 of the rotating plate 101. That is, the link 110 has an outer peripheral end rotatably connected to the holding member 81 via the shaft portion 84, and an inner peripheral end connected to the tip of the arm portion 103 of the rotary plate 101 via the pin 115. Is pivotally connected to the motor.

  The air cylinder 120 is configured such that the piston rod 122 expands and contracts by the air supply / discharge action with respect to the cylinder body 121, and a ring 123 is formed at the tip of the piston rod 122. In the air cylinder 120, the cylinder main body 121 is fixed on the support plate 91, and the ring 123 of the piston rod 122 is rotatable on a pin 106 formed in the middle portion of one arm portion 103 of the rotation plate 101. It is inserted in.

  As shown in FIG. 6A, when the holding member 81 is at the outer peripheral end of the long hole 92, the link 110 and the arm portion 103 of the rotating plate 101 are in a straight line with the long hole 92. . At this time, the piston rod 122 is in a contracted state and is orthogonal to the arm portion 103. When the piston rod 122 extends from this state, as shown in FIG. 6B, the arm portion 103 is pushed and the rotation plate 101 rotates. Then, the link 110 is pulled to the inner peripheral side, and the holding member 81 moves through the long hole 92 to the end portion on the inner peripheral side. In addition, when the piston rod 122 contracts from this state, the piston rod 122 operates in reverse, and the holding member 81 moves to the outer peripheral end of the long hole 92 as shown in FIG.

  As the rotation plate 101 rotates in this way, the holding members 81 are reciprocated along the long holes 92 in synchronization. That is, when the piston rod 122 of the air cylinder 120 extends, the holding members 81 move toward the inner peripheral side so as to approach each other, and when the piston rod 122 contracts, the holding members 81 expand toward the outer side so as to spread apart from each other. Moving. Note that the washer 114 interposed between the support plate 91 and the arm portion 103 is preferably made of a low friction member from the viewpoint of making the reciprocating movement of the holding member 81 smoother.

  A plurality of spacer pins 95 projecting downward are formed at equal intervals in the circumferential direction on the outer peripheral portion of the lower surface of the support plate 91. In this case, a total of three spacer pins 95 are formed, one each at a position between the long holes 92. The spacer pin 95 protrudes perpendicularly to the lower surface of the support plate 91, and its length is set such that the lower end is located below the lower surface of the holding member 81. In the work holding mechanism 80, the support plate 91 is positioned immediately above the chuck table 30 and holds the work 9 by the holding member 81. At this time, the spacer pins 95 abut against the upper surface of the chuck table 30, This prevents the holding member 81 from coming into contact with the chuck table 30. Note that the length of the spacer pin 95 is set so as to protrude from the lower end of the holding member 81 by, for example, about 0.5 mm.

  On the upper surface of the support plate 91, around the stepped nut 93, three support pillars 96 extending upward are erected at equal intervals in the circumferential direction. Each support column 96 is inserted through each arc hole 104 of the rotating plate 101 and a hole 73 a formed in the flange 73 at the tip of the arm 72. Screw holes 96 a are formed in the upper end surface of the support column 96, and screws 97 are screwed into the screw holes 96 a from above the flange 73. The support column 96 is inserted into the hole 73 a of the flange 73 in a loosely fitted state. The support column 96 is covered with a coil spring 98 that is sandwiched between the flange 73 and the support plate 91 and is in a compressed state. The coil spring 98 is loosely fitted into the arc hole 104. It is inserted through.

  With such a configuration, the support plate 91 to which the holding member 81 is attached is always elastically biased downward by the coil spring 98 in a normal state, and the fall is prevented by the screw 97. When a stress for moving upward is applied to the support plate 91 (greater than the biasing force of the coil spring 98), the coil spring 98 is contracted and displaced upward so that the support plate 91 approaches the flange 73. It is possible to do.

  As shown in FIG. 5, a tube (water supply means) 130 made of an elastic material is passed through the center of the arm 72. The tube 130 has a distal end protruding from the distal end of the arm 72, a hole 73 b formed in the center of the flange 73, a hole 94 a formed in the screw 94 screwed into the stepped nut 93, and the center of the support plate 91. Is disposed through the hole 91a. The tube 130 is connected to a water supply source, is passed through the rotary shaft 71 into the arm 72, and water is discharged from a tip opening below the support plate 91.

[4] Operation of Recovery Unit The recovery unit 70 having the above configuration transfers the workpiece 9 including the wafer 1 subjected to back grinding from the chuck table 30 to the spinner type cleaning device 60. Hereinafter, the operation will be described with reference to FIGS. 7 to 13 (these figures are schematic diagrams in which some components are omitted).

  As shown in FIG. 7, the work 9 including the wafer 1 ground on the back surface is attracted and held on the chuck table 30 at the work attachment / detachment position. The arm 72 is turned in a state where the rotation shaft 71 of the collecting means 70 is raised, and the work holding mechanism 80 is positioned above the work 9. The work holding mechanism 80 is positioned so that the support plate 91 is substantially concentric with the work 9. Each holding member 81 of the work holding mechanism 80 is moved to the outer peripheral side. In the illustrated example, the arm 72 is slightly tilted and the flange 73 is also tilted. Therefore, the work holding mechanism 80 is also tilted. This is based on, for example, an assembly error of the rotating shaft 71 to the supply / collection stage 12 or an assembly error of the arm 72 to the rotating shaft 71.

  Next, the rotating shaft 71 is lowered, and the work holding mechanism 80 is lowered until all the spacer pins 95 come into contact with the upper surface of the chuck table 30 as shown in FIG. Even if the work holding mechanism 80 is in an oblique posture together with the arm 72, the coil spring 98 is contracted by being lowered as it is, and the tips of all the spacer pins 95 are brought into contact with the upper surface of the chuck table 30, thereby supporting it. The plate 91 is parallel to the chuck table 30. In this state, the holding member 81 is located immediately above the chuck table 30 and is surrounded by the surrounding spacer pins 95.

  Next, the vacuum operation of the chuck table 30 is switched to the blow operation. Then, the workpiece 9 floats as shown in FIG. 9, and the outer peripheral edge comes into contact with the upper tapered surface 82a of the engaging portion 83 of each holding member 81 or stops at a height just below the upper tapered surface 82a. It becomes. Subsequently, the blow operation of the chuck table 30 is stopped, and at the same time, the piston rod 122 of the air cylinder 120 is extended to rotate the rotating plate 101 and each holding member 81 is moved to the inner peripheral side as shown in FIG. Let As a result, the engaging recess 82 of the engaging portion 83 is fitted into the outer peripheral edge of the work 9, and the work 9 is engaged with and held by the engaging portions 83 of the three holding members 81. Since the wafer 1 is adhered to the substrate 5 and the rigidity is ensured, the wafer 1 is held by the holding members 81 in a substantially horizontal state without being bent.

  When the workpiece 9 is held by each holding member 81, the rotary shaft 71 is raised to lift the workpiece 9 as shown in FIG. 11, and water W is discharged from the tube 130. The water W is supplied to the upper surface which is the surface of the work 9 facing the support plate 91, that is, the rear surface of the ground wafer 1. In this way, the arm 72 is turned while supplying water, and the work 9 held by the work holding mechanism 80 is transferred to the spinner type cleaning device 60. After the workpiece 9 is positioned concentrically above the spinner table 61, the rotary shaft 71 descends.

  Next, as shown in FIG. 12, the work holding mechanism 80 is lowered until all the spacer pins 95 come into contact with the upper surface of the spinner table 61, and then the piston rod 122 of the air cylinder 120 is contracted. Then, as shown in FIG. 13, the holding member 81 moves to the outer peripheral side, and the workpiece 9 slides down the lower tapered surface 82 b of the engaging portion 83 and is placed on the spinner table 61. The spinner table 61 is previously operated in vacuum, and the workpiece 9 is attracted and held on the spinner table 61. Thereafter, the supply of water from the tube 130 is stopped, and the collecting means 70 is returned from the chuck table 30 to the workpiece attaching / detaching position where the workpiece 9 is picked up. On the other hand, the wafer 1 of the workpiece 9 on the spinner table 61 is cleaned and dried.

[5] Effects of Work Holding Mechanism The work holding mechanism 80 according to the present embodiment holds the outer peripheral edge of the work 9 and keeps the back surface, which is the surface to be ground, of the wafer 1 exposed upward, while maintaining the wafer. The workpiece 9 is transferred from the chuck table 30 to the spinner type cleaning device 60 while supplying water from the tube 130 to the back surface of 1. Since the wafer 1 is conveyed to the spinner type cleaning device 60 with the back surface always wet with water, drying is prevented. That is, the back surface of the wafer 1 is maintained in a state in which dirt is easily removed by washing with water. For this reason, the wafer 1 is sufficiently cleaned by the spinner cleaning device 60.

  In addition, the support plate 91 can be made parallel to the chuck table 30 by bringing the tip of the spacer pin 95 projecting from the lower surface of the support plate 91 into contact with the upper surface of the chuck table 30. Further, the movement of the workpiece 9 in the horizontal direction can be restricted by the spacer pin 95. For this reason, it becomes easy to guide and hold the workpiece 9 on the holding member 81, and the holding member 81 is prevented from coming into contact with the chuck table 30 to prevent the holding member 81 from being damaged.

  The driving mechanism for reciprocating the plurality (three) of the holding members 81 is not limited to the configuration in which the rotating plate 101 of the above embodiment is rotated by one air cylinder 120, and each holding member 81 is individually moved. It does not matter even if it is driven independently. However, according to the above-described embodiment, the number of parts does not increase and the structure can be simplified as compared with the case where each holding member 81 is reciprocated individually, so that an increase in cost can be suppressed. .

  In the above-described embodiment, the workpiece holding mechanism of the present invention is applied to the collecting means 70 of the wafer grinding apparatus 10, but the present invention is not limited to this embodiment, and in other processing apparatuses. The present invention can be applied to a workpiece transfer means.

It is a perspective view of the semiconductor wafer ground back by the wafer grinding processing device concerning one embodiment of the present invention. 1 is a perspective view of a wafer grinding apparatus according to an embodiment of the present invention. It is a perspective view of the collection | recovery means with which the wafer grinding processing apparatus is provided. It is a disassembled perspective view of the collection | recovery means. It is sectional drawing of the collection | recovery means. It is a top view which shows the effect | action of the moving means with which the collection | recovery means is provided, Comprising: (a) The state which is moving the holding member to the outer peripheral side, (b) The state which is moving the holding member to the inner peripheral side. It is a partial cross section side view which shows the workpiece conveyance process by the collection | recovery means, Comprising: It is an initial state (positioning above a chuck table). It is a partial cross section side view which shows the same conveyance process, Comprising: It is the state which contacted the spacer pin of the support plate to the chuck table. It is a partial cross section side view which shows the conveyance process, Comprising: It is the state which floated the workpiece | work. It is a partial cross section side view which shows the conveyance process, Comprising: It is the state which hold | maintained the workpiece | work with the holding member. It is a partial cross section side view which shows the conveyance process, Comprising: It is the state which is conveying the workpiece | work, supplying water to the wafer upper surface. It is a partial cross section side view which shows the conveyance process, Comprising: It is the state which conveyed the workpiece | work on the spinner table of a spinner type cleaning apparatus. It is a partial cross section side view which shows the last step of the conveyance process, Comprising: It is the state which hold | maintained the workpiece | work on the spinner table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wafer 9 ... Workpiece 10 ... Wafer grinding processing apparatus 30 ... Chuck table 32a ... Upper surface (mounting surface) of chuck table
80 ... Work holding mechanism 81 ... Holding member 82 ... Engaging recess 82a ... Upper taper surface (work receiving surface)
83 ... engaging portion 84 ... shaft portion (guide supported portion)
91 ... support plate 92 ... long hole (guide part)
93 ... Stepped nut (rotating shaft)
95 ... Spacer pin 100 ... Moving means 101 ... Turning plate 110 ... Link 120 ... Air cylinder (turning drive means)
130 ... Tube (water supply means)
W ... water

Claims (5)

Three or more holding members for holding the outer peripheral edge of the disk-shaped workpiece;
The support member is positioned to face the workpiece whose outer peripheral edge is held by the holding member, and has a guide portion that guides the holding member in the radial direction, and supports the holding member movably along the guide portion. Plates,
Moving means for moving the holding member along the guide;
A work holding mechanism comprising at least water supply means for supplying water to a surface of the work held by the holding member facing the support plate. The guide part is composed of a long hole formed in the support plate and extending in the radial direction,
The holding member includes an engaging portion having an engaging recess that engages with an outer peripheral edge of the workpiece;
The work holding mechanism according to claim 1, further comprising a guided support portion provided in the engaging portion and inserted through the elongated hole.   The holding member is formed between the work plate and the support plate, which is continuous with the engaging recess and has an outer peripheral edge engaged with the engaging recess, and the outer peripheral edge of the work is formed into the engaging recess. The work holding mechanism according to claim 2, further comprising a tapered work receiving surface for guiding. The moving means is
A rotating plate that is pivotally attached to a substantially center of the support plate via a rotating shaft;
A link provided for each of the holding members, one end of which is connected to the holding member and the other end of the link is rotatably connected to the rotating plate;
The work holding mechanism according to claim 1, further comprising a rotation driving unit that rotates the rotation plate. The workpiece is placed on a predetermined placement surface,
A plurality of spacer pins are provided on the surface of the support plate facing the workpiece held by the holding member so as to ensure a certain distance between the facing surface and the mounting surface. The workpiece holding mechanism according to any one of claims 1 to 4, wherein the workpiece holding mechanism is provided.

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