JP2006054388A - Workpiece-conveying equipment, spinner-cleaning equipment, grinder, workpiece-conveying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide workpiece-conveying equipment in which a workpiece can be conveyed while being properly sucked, even when the peripheral portion is warped. <P>SOLUTION: The workpiece-conveying equipment comprises a workpiece holding section 22 for supporting the peripheral portion of a workpiece 50 mounted on a table 32 from underside, means 42 and 44 for jetting air against the peripheral portion of the workpiece 50 mounted on a table 32 from upper side, a suction pad 24 provided at the workpiece holding section 22, in order to suction hold the peripheral portion of the workpiece, and a means for moving the workpiece-holding section 22, which is suction holding the workpiece by means of the suction pad 24. Warpages at the peripheral portion of the workpiece 50 is corrected by jetting of air, and the workpiece 50 is brought into tight contact with the workpiece-holding section 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a workpiece conveyance device, a spinner cleaning device, a grinding device, and a workpiece conveyance method, and in particular, a workpiece for suitably holding and conveying a workpiece such as a semiconductor wafer whose outer peripheral portion is warped. The present invention relates to an object conveying apparatus, a spinner cleaning apparatus, a grinding apparatus, and a workpiece conveying method.

  In recent years, in order to realize miniaturization of electronic devices using a semiconductor chip, it is required to make the semiconductor chip thinner. For this reason, before the semiconductor wafer is diced and divided into individual semiconductor chips, the back surface of the semiconductor wafer is ground by a grinding device (grinder) so that the semiconductor wafer has a predetermined thickness (for example, 50 to 100 μm) or less. Thinner.

  As described above, the grinding device for grinding the back surface of the semiconductor wafer includes a cleaning device for cleaning the contamination adhering to the ground processing surface. As this cleaning device, for example, a spinner cleaning device is generally used. This spinner cleaning apparatus sucks, holds, and rotates a semiconductor wafer placed with the processing surface (back surface) facing upward, and supplies a cleaning liquid to the processing surface of the semiconductor wafer held on the spinner table. A cleaning liquid supply means (see Patent Document 1).

  In order to transport the semiconductor wafer cleaned by such a spinner cleaning apparatus from the spinner table to a storage cassette, a transfer means (robot pick or the like) is used. This transport means includes, for example, a C-shaped or U-shaped wafer holding portion provided with a suction pad, and the lower surface of the semiconductor wafer placed on the spinner table (by this wafer holding portion) In this configuration, the outer peripheral portion (on the circuit surface side on which the grinding tape is affixed) is picked up, picked up and transported.

  However, after the semiconductor wafer is ground back, the outer periphery of the semiconductor wafer may be warped depending on the finished thickness and the type of tape. In particular, when a semiconductor wafer is ground to an extremely thin thickness, the occurrence of warpage is remarkable. When such a semiconductor wafer is transported by the transport means, since the outer peripheral portion of the semiconductor wafer is warped, the wafer holder and the semiconductor wafer are not in close contact with each other, and a gap is left between them. For this reason, there is a problem that air leakage (air leak) occurs between the wafer holding part and the semiconductor wafer, and the semiconductor wafer cannot be attracted and held well.

  In addition, for example, as described in Patent Document 2, a suction pad is annularly arranged on the outer peripheral portion, and a semiconductor placed on a spinner table by a “champer type” wafer holder having the same diameter as the semiconductor wafer. A method of attracting and holding a wafer from the upper surface (ground surface to be ground) has been proposed. According to this method, a negative pressure is also generated inside the annularly arranged suction pad, and the semiconductor wafer can be sucked and held by the entire wafer holding portion, so that even a semiconductor wafer having a curved outer peripheral portion can be held. And can be conveyed.

  However, this method has a problem that the processing surface is damaged because the wafer holder is held in contact with the processing surface of the semiconductor wafer.

  Also, when a semiconductor wafer placed on a spinner table with the processing surface (back surface) facing up is transported and inserted into a slot of a cassette, the circuit surface on the side where the grinding tape of the semiconductor wafer is affixed Often stored with the (surface) facing up. Thus, in order to store the semiconductor wafer in the slot of the cassette, it is necessary to invert the semiconductor wafer. However, when the wafer holding unit that holds the processed surface side of the semiconductor wafer by suction is reversed by the above method, the wafer holding unit is positioned below the semiconductor wafer. On the other hand, the cassette slot supports the semiconductor wafer from below. For this reason, when there is a wafer holding part on the lower side as described above, there is a problem that it is very difficult to insert the semiconductor wafer into the slot and place it.

JP 2003-273055 A JP 2003-303847 A

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a case where the outer peripheral portion of a workpiece placed on a table is along the same. A new and improved workpiece transfer device, spinner cleaning device, and grinding device that can be suitably held by suction (for example, the surface opposite to the grinding surface) and can be easily stored in a cassette. , And a method of conveying a workpiece.

  In order to solve the above-described problems, according to an aspect of the present invention, there is provided a workpiece conveyance device that conveys a workpiece placed on a table. The workpiece conveying apparatus includes a workpiece holding unit that supports an outer peripheral portion of the workpiece placed on the table from below; an upper side with respect to the outer peripheral portion of the workpiece placed on the table; Air injection means for injecting air from; a suction pad provided on the work piece holding portion and sucking and holding the outer periphery of the work piece; and moving the work piece holding portion holding the work piece by suction suction And a moving means for making it possible.

  With such a configuration, it is possible to correct the warpage of the outer peripheral portion of the workpiece by injecting air and to bring the outer peripheral portion of the workpiece into close contact with the workpiece holding portion. For this reason, air leakage does not occur between the outer peripheral portion of the workpiece and the workpiece holding portion, so that the outer peripheral portion of the workpiece can be favorably sucked and held by the suction pad.

  The air injection means includes a plurality of air injection nozzles arranged at substantially equal intervals along the outer peripheral portion of the workpiece; a nozzle support portion that supports the plurality of air injection nozzles; Elevating and lowering means to be provided. Thus, only when the workpiece is sucked and held by the workpiece holding portion, the nozzle support portion can be lowered by the elevating means and the injection nozzle can be positioned above the outer peripheral portion of the workpiece.

  Further, the workpiece holding portion is formed in a substantially C-shaped flat plate shape having a pair of arcuate portions opposed to each other, a base portion connecting the pair of arcuate portions is coupled to a moving means, and the suction pad is Each arcuate part may be configured to be disposed at a substantially symmetrical position about an axis passing through the middle and base of the pair of arcuate parts at least two at intervals. Thereby, a plurality of suction pads can be arranged in a well-balanced manner on the workpiece holding portion, and the workpiece can be stably held.

  The table includes a main table having a suction holding surface for sucking and holding a central portion of the workpiece; a support table having a support surface for supporting the outer peripheral portion of the workpiece; and a support table for the support table. And a support table positioning means for selectively positioning at a working position substantially flush with or slightly lower than the suction holding surface of the table and a non-working position retracted downward from the working position. May be configured to support the outer peripheral portion of the workpiece placed on the main table from the lower side when the support surface of the support table is in the non-operating position. As a result, the workpiece placed on the main table having a smaller area than the workpiece can be suitably picked up and conveyed while the lower surface side is sucked and held.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a spinner cleaning apparatus including the workpiece transfer device.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, the grinding device provided with the said spinner washing | cleaning apparatus is provided.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, the workpiece conveying method which conveys the workpiece mounted in the table is provided. The workpiece conveying method includes: (1) a supporting step of supporting the outer peripheral portion of the workpiece placed on the table from below by the workpiece holding portion; and (2) the workpiece placed on the table. An air injection step of injecting air from the upper side to the outer periphery of the workpiece and bringing the outer periphery of the workpiece into close contact with the workpiece holding portion; and (3) the workpiece in close contact with the workpiece holding portion. A suction holding step in which the outer peripheral portion of the workpiece is sucked and held by a suction pad provided on the workpiece holding portion; (4) the workpiece holding portion holding the workpiece by suction is moved, and the workpiece is moved And a conveying step for conveying.

  As described above, according to the present invention, even when the outer peripheral portion of the workpiece is warped, the warp of the outer peripheral portion of the workpiece is flattened by the air injection means, and the workpiece holding portion Can be adhered to. For this reason, the workpiece can be suitably held by suction and transported by the suction pad of the workpiece holding portion.

  In addition, the workpiece holding unit can convey the workpiece holding unit while holding the lower surface of the workpiece (for example, the surface opposite to the grinding surface). For this reason, since the workpiece holding part does not contact the processing surface of the workpiece, the processing surface is not damaged. Furthermore, when the conveyed workpiece is stored in the cassette, it can be easily stored with the workpiece inverted and the circuit surface facing upward.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, based on FIG. 1, the whole structure of the grinding device 1 provided with the workpiece conveying apparatus concerning the 1st Embodiment of this invention is demonstrated. FIG. 1 is a perspective view showing the overall configuration of the grinding apparatus 1 according to the present embodiment.

  The grinding device 1 is configured as a device for grinding the back surface of a semiconductor wafer 50 that is an example of a workpiece. The semiconductor wafer 50 is, for example, a substantially disk-shaped silicon wafer such as 8, 12 inches. A gliding tape (hereinafter simply referred to as “tape”), which is an adhesive tape for surface protection, is attached to the surface of the semiconductor wafer 50 (circuit surface on which semiconductor elements are formed). The grinding apparatus 1 grinds the back surface (surface opposite to the circuit surface) of the semiconductor wafer 50 to reduce the thickness to, for example, 50 to 100 μm.

  Each component of the grinding apparatus 1 will be specifically described. As shown in FIG. 1, the grinding apparatus 1 includes, for example, a housing 2, a rough grinding unit 3, a finish grinding unit 4, for example, three chuck tables 6 installed on a turntable 5, and cassettes 11 and 12. The temporary placement table 13, the transfer arms 16 and 17, the transfer means 20, the spinner cleaning device 30, and the air injection means 40 are mainly provided.

  The rough grinding unit 3 performs rough grinding on the back surface of the semiconductor wafer 50 by pressing the back surface of the semiconductor wafer 50 held on the chuck table 6 while rotating the grinding wheel 3b mounted on the lower end of the spindle 3a. . Similarly, the finish grinding unit 4 presses the back surface of the semiconductor wafer 50 after the rough grinding while rotating the grinding wheel 4b mounted on the spindle 4a, thereby causing the back surface of the semiconductor wafer 50 to be pressed. Finish grinding with high accuracy. As described above, the grinding apparatus 1 according to the present embodiment includes the two grinding units 3 and 4. However, the present invention is not limited to this example, and the grinding apparatus includes only one grinding unit or three or more grinding units. It can also be configured to.

  The turntable 5 is a relatively large-diameter disk-shaped table provided on the upper surface of the housing 2 and can be rotated in the horizontal direction. On the turntable 5, for example, three chuck tables 6 are arranged at equal intervals with a phase angle of 120 degrees, for example. The chuck table 6 has a vacuum chuck on the upper surface thereof, and holds the semiconductor wafer 50 placed thereon by vacuum suction. The chuck table 6 can be rotated in the horizontal direction by a rotation drive mechanism (not shown) during grinding. Each chuck table 6 having such a configuration is sequentially moved to the carry-in / carry-out region A, the rough grinding region B, the finish grinding region C, and the carry-in / carry-out region A by the rotation of the turntable 5.

  The cassettes 11 and 12 are semiconductor wafer containers having a plurality of slots, and horizontally store one semiconductor wafer 50 in each slot. The cassette 11 accommodates the semiconductor wafer 50 before grinding, while the cassette 12 accommodates the semiconductor wafer 50 after grinding. When the ground semiconductor wafer 50 is accommodated in the cassette 12, for example, it is accommodated with the circuit surface side to which the tape is attached facing upward (the ground processing surface is directed downward).

  The temporary placement table 13 is a table on which the semiconductor wafer 50 taken out from the cassette 11 is temporarily placed. The temporary placement table 13 includes a center alignment mechanism that aligns the center position of the semiconductor wafer 50 by simultaneously reducing the diameter of, for example, six pins toward the center of the table.

  The transfer arms 16 and 17 are provided with an adsorbing unit that adsorbs the semiconductor wafer 50 from above, an arm unit that supports the adsorbing unit, and a rotation drive unit that rotates the arm unit in the horizontal direction. The transfer arm 16 transfers the pre-grinding semiconductor wafer 50 placed on the temporary placement table 13 and places it on the chuck table 6 located in the loading / unloading area A. Further, the transfer arm 16 transfers the ground semiconductor wafer 50 placed on the chuck table 6 positioned in the carry-in / out area A and places it on the spinner table 32 of the spinner cleaning device 30.

  The conveyance means 20 is a conveyance device (robot pick) provided with a workpiece holding portion 22 (for example, a C-shaped hand) provided with a suction pad (not shown). The transport means 20 sucks and holds the semiconductor wafer 50 by the workpiece holder 22 and transports it. Specifically, the transport unit 20 takes out the semiconductor wafer 50 in the cassette 11 and transports it to the temporary placement table 13. Further, the transfer means 20 picks up and transfers the semiconductor wafer 50 placed on the spinner table 32 of the spinner cleaning device 30 and stores it in the cassette 12. Details of the conveying means 20 will be described later.

  The spinner cleaning device 30 cleans the semiconductor wafer 50 after grinding and removes contamination such as grinding debris and dirt attached to the ground processing surface. Details of the spinner cleaning apparatus 30 will be described later.

  The air ejecting means 40 is provided on the upper portion of the spinner cleaning device 30 so as to be movable up and down, and is installed on a support base 18 provided on the housing 2. The air ejecting means 40 ejects air (air) from above to the outer peripheral portion of the semiconductor wafer 50 placed on the spinner table 32 to correct the warpage of the outer peripheral portion of the semiconductor wafer W. Details of the air ejecting means 40 will be described later. In addition, the conveyance means 20 and the air injection means 40 concerning this embodiment comprise the workpiece conveyance apparatus.

  Next, the operation of the grinding apparatus 1 having the above configuration will be described. The semiconductor wafer 50 before grinding is placed on the cassette 11 with, for example, the circuit surface (front surface) on which the tape is attached facing down (that is, the back surface to be ground is facing up). Therefore, first, the transfer means 20 takes out and transfers one semiconductor wafer 50 in the cassette 11 and places it on the temporary table 13. Next, the temporary placement table 13 aligns the center of the placed semiconductor wafer 50. Further, the transfer arm 16 picks up and transfers the semiconductor wafer 50 aligned with the center, and places it on the chuck table 6 arranged in the carry-in / out area A. The chuck table 6 holds the semiconductor wafer 50 placed thereon by vacuum suction.

  Next, the turntable 5 is rotated so that the chuck table 6 holding the semiconductor wafer 50 is moved to the rough grinding region B and positioned below the rough grinding unit 3. In this state, the back surface of the semiconductor wafer 50 is roughly ground by the rough grinding unit 3. Further, the turntable 5 is rotated so that the chuck table 6 holding the roughly ground semiconductor wafer 50 is moved to the finish grinding region C and positioned below the finish grinding unit 4. In this state, the back surface of the semiconductor wafer 50 is finish ground by the finish grinding unit 4. Simultaneously with this finish grinding, the grinding process can be made more efficient by subjecting another subsequent semiconductor wafer 50 to the rough grinding unit 3 rough grinding.

  Next, the turntable 5 is further rotated to move the chuck table 6 holding the semiconductor wafer 50 subjected to the finish grinding to the carry-in / carry-out area A. Next, the semiconductor wafer 50 subjected to finish grinding is picked up and transferred by the transfer arm 17 and placed on the spinner table 32 of the spinner cleaning device 30. The spinner cleaning device 30 is configured to spray the cleaning liquid onto the back surface (grinded processed surface) of the semiconductor wafer 50 while rotating the semiconductor wafer 50 adsorbed and held by the spinner table 32, thereby cleaning the adhered contamination. Remove and dry further.

  Thereafter, the conveying means 20 picks up the lower surface (circuit surface) side of the cleaned and dried semiconductor wafer 50 by sucking and holding the workpiece holding portion 22 (C-shaped hand). Further, the transport means 20 transports the semiconductor wafer 50 held by suction, and stores the semiconductor wafer 50 in the cassette 12 after turning the semiconductor wafer 50 upside down.

  As described above, in the grinding apparatus 1, after the back surface of the semiconductor wafer 50 is ground, the semiconductor wafer 50 is moved to the spinner cleaning apparatus 30 in order to clean the semiconductor wafer 50. At this time, a tape is attached to the circuit surface of the semiconductor wafer 50 to protect the circuit surface. The semiconductor wafer 50 is placed on the spinner table 32 with the circuit surface facing down (that is, the processing surface facing up). After the semiconductor wafer 50 is cleaned by the spinner cleaning device 30, the semiconductor wafer 50 is transferred from the spinner cleaning device 30 to the cassette 12 by the transfer means 20. At this time, as described above, when the outer peripheral portion of the semiconductor wafer 50 is warped, there is a problem in that the semiconductor wafer 50 cannot be favorably held by the workpiece holder 22.

  More specifically, with the recent increase in size and thickness of the semiconductor wafer 50, if the backside grinding of the semiconductor wafer 50 is performed, the outer peripheral portion of the semiconductor wafer 50 warps to the processing surface side, depending on the type. A phenomenon occurs. In this case, when the semiconductor wafer 50 is vacuum-sucked and held from below by the suction pad of the workpiece holding unit 22, the outer peripheral portion of the semiconductor wafer 50 and the workpiece holding unit 22 are not in close contact with each other. , Air leaked and could not be properly adsorbed.

  In order to cope with such a problem, the grinding apparatus 1 according to the present embodiment includes a workpiece transfer device including the transfer means 20 and the air injection means 40. That is, air is jetted from above onto the outer peripheral portion of the semiconductor wafer 50 by the air jetting means 40, thereby flattening the outer peripheral portion of the semiconductor wafer 50 by the jetting pressure and bringing it into close contact with the workpiece holding portion 22. The holding part 22 is characterized in that the circuit surface side of the semiconductor wafer 50 can be suitably sucked and held from below.

  In the following, such features of the workpiece transfer device will be described in detail. As described above, the workpiece transfer apparatus according to this embodiment includes the transfer means 20 and the air injection means 40.

  Therefore, first, the transport unit 20 (robot pick) according to the present embodiment will be described in detail with reference to FIG. FIG. 2 is a perspective view showing the conveying means 20 according to the present embodiment.

  As shown in FIG. 2, the conveying means 20 includes a workpiece holding unit 22 that holds a semiconductor wafer 50, a plurality of suction pads 24 provided on the workpiece holding unit 22, and a workpiece holding unit 22. A moving means 28 for moving in the vertical direction and the horizontal direction, and a connecting shaft 26 for connecting the workpiece holder 22 and the moving means 28 are provided.

  The workpiece holding part 22 is comprised by the C-type hand which has a substantially C-shaped flat plate shape, for example. The workpiece holding portion 22 includes a pair of arcuate portions 222a and 222b facing each other and a base portion 224 that connects the pair of arcuate portions 222a and 222b.

  The arc-shaped portions 222a and 222b (hereinafter sometimes collectively referred to as “arc-shaped portions 222”) are flat plate-like shapes having a radius of curvature and a shape along the outer peripheral portion of the workpiece (semiconductor wafer 50) to be held. It is a member. The arc-shaped portion 222a and the arc-shaped portion 222b are provided in a line-symmetric shape and arrangement with the axis 223 as the center. The axis 223 is an imaginary straight line passing between the middle of the pair of arcuate portions 222 and the base portion 224, and is also a rotation axis of the workpiece holding portion 222 when the held semiconductor wafer 50 is reversed.

  Further, the tip portions of both arc-shaped portions 222 are spaced apart by a predetermined gap, and the support portion of the spinner table 32 can be inserted between the two arc-shaped portions 222 through the gap. The holding surface (upper surface in FIG. 2) of the arc-shaped portion 222 is substantially flat, and the outer peripheral portion of the semiconductor wafer 50 is supported from below by this holding surface.

  Further, for example, six suction pads 24 are provided on the holding surface of the arc-shaped portion 222 of the workpiece holding portion 22. The suction pad 24 communicates with an external vacuum pump (not shown) via an exhaust path (not shown) provided inside the workpiece holding portion 22 and is generated by the vacuum pump. The semiconductor wafer 50 is vacuum-sucked and held by the negative pressure. These six suction pads 24 are disposed, for example, in the arc-shaped portions 222a and 222b at symmetrical positions with the axis 223 as the center, for example, three at intervals. As a result, the semiconductor wafer 50 can be held in a balanced manner by the plurality of suction pads 24.

  The suction pads 24 may be provided in the same number (at least two) in each arcuate portion 222a, 222b at symmetrical positions about the axis 223, and the number and arrangement of the suction pads 24 are not limited to the example of FIG. .

  The moving means 28 is comprised from an arm, a rotating shaft, an electric motor, etc., for example. The moving means 28 moves the workpiece holder 22 in the vertical direction (Z direction) and the horizontal direction (X, Y direction), or rotates the workpiece holder 22 around the axis 223 as a rotation axis. can do.

  Specifically, the moving means 28 includes, for example, a vertical movement means 282 that moves the workpiece holding portion 22 up and down in the vertical direction (Z direction), a turning shaft 283 attached to the vertical movement means 22, A first arm 284 that is attached to the upper end of the H.283 and pivotably moves on the horizontal plane (XY plane), and a first arm 284 that is pivotally moved on the horizontal plane (XY plane) and attached to the end of the first arm 284. 2 arms 285, and a support rotating portion 286 provided at the tip of the second arm 285 and connected to the connecting shaft 26. The support rotation unit 286 supports the workpiece holding unit 22 via the connecting shaft 26. Further, the support rotating unit 286 rotates the supported workpiece holding unit 22 around the connection shaft 26 (axis line 223) as a rotation axis. Thereby, the semiconductor wafer 50 sucked and held by the workpiece holding unit 22 can be reversed.

  The transport means 20 having the above configuration can hold the semiconductor wafer W by sucking the outer peripheral portion of one surface of the semiconductor wafer 50 by the suction pad 24 of the workpiece holding portion 22. Further, the transport unit 20 can transport the held semiconductor wafer 50 by moving the workpiece holding unit 22 by the moving unit 28. However, when the semiconductor wafer 50 whose outer peripheral portion is warped upward is sucked and held from below (for example, when the warped semiconductor wafer 50 placed on the spinner table 32 or the like is sucked and held), the air described later is used. After correcting the warp of the semiconductor wafer 50 by the jetting means 40, it is necessary to suck and hold the workpiece by the workpiece holding means 22.

  Next, based on FIGS. 3 and 4, the spinner cleaning device 30 and the air injection means 40 according to the present embodiment will be described in detail. FIG. 3 is a perspective view showing the spinner cleaning device 30 and the air ejecting means 40 according to the present embodiment. FIG. 4 is a plan view showing the air injection means 40 according to the present embodiment.

  First, the configuration of the spinner cleaning device 30 will be described. As shown in FIG. 3, the spinner cleaning device 30 includes a table housing 31, a spinner table 32, a support table 34, a support table positioning means (not shown), a side spinner cover 37, and an upper spinner cover 38. And a cleaning liquid supply means (not shown) and a high-pressure air supply means (not shown).

  The spinner table 32 is a substantially disk-shaped table with a flat upper surface, and functions as a main table that holds the central portion of the semiconductor wafer 50 by suction. The spinner table 32 includes a vacuum chuck 322 made of a porous ceramic disk on the upper surface, and holds the central portion of the lower surface of the semiconductor wafer 50 by vacuum suction. The upper surface of the spinner table 32 forms a circular flat suction holding surface 321. Further, the outer diameter of the spinner table 32 is smaller than the outer diameter of the semiconductor wafer 50. For this reason, when the semiconductor wafers 50 are placed on the spinner table 32 with their center positions aligned with each other, the outer periphery of the semiconductor wafer 50 protrudes from the outer edge of the spinner table 32 and the outer periphery of the lower surface of the semiconductor wafer 50 is The part will be exposed.

  The support portion 324 that supports the spinner table 32 is coupled to a rotation drive mechanism (not shown) disposed in the table housing 31. Thus, during cleaning, the spinner table 32 holding the semiconductor wafer 50 by suction can be rotated in the horizontal direction.

  The support table 34 supports the outer peripheral portion of the lower surface of the semiconductor wafer 50 held by suction on the spinner table 32. The support table 34 is formed in a ring shape using a metal material such as an aluminum alloy, and has a through hole 342 into which the spinner table 32 can be inserted. The upper surface of the support table 34 forms an annular flat support surface 341. The support table 34 supports the outer peripheral portion of the lower surface of the semiconductor wafer 50 sucked and held on the spinner table 32 by the support surface 341.

  The support table positioning means (not shown) raises and lowers the support table 34 in the vertical direction so that the support surface 341 of the support table 34 is flush or slightly flush with the suction holding surface 321 of the spinner table 32. It is selectively positioned at a low action position and a non-action position retracted downward from this action position.

  More specifically, the support table positioning means is constituted by a drive mechanism such as an air cylinder provided below the support table 34. This support table positioning means raises the support table 34 by the operation of the air cylinder at the time of cleaning and positions the support surface 341 at the working position. On the other hand, the support table positioning means supports the operation by the operation of the air cylinder at the time of transporting the semiconductor wafer 50. The table 34 is lowered to position the support surface 341 at the non-operating position.

  The support table 34 is set so that the support surface 341 is slightly lower (for example, 1 to 3 mm) than the suction holding surface 321 of the spinner table 32 when the support table 34 is positioned at the above-described operation position. The non-operating position of the support table 34 is set to a sufficiently low position so as not to be an obstacle when the workpiece holding portion 22 is inserted below the semiconductor wafer 50.

  The side surface spinner cover 37 is a movable cover that covers the side of the cleaning region of the spinner cleaning device 30. The upper spinner cover 38 is a flat cover that covers the upper portion of the cleaning region of the spinner cleaning device 30. For example, a piston rod 372 of an air cylinder 371 fixed to the housing 31 is connected to the side surface spinner cover 37. At the time of cleaning, the side spinner cover 37 is raised by the driving force of the air cylinder 371 and abuts on the upper spinner cover 38. Thus, the cleaning area of the spinner cleaning device 30 can be covered by the side surface and upper surface spinner covers 37 and 38 to prevent the cleaning liquid from splashing. On the other hand, when the semiconductor wafer 50 is loaded / unloaded, the side surface spinner cover 37 is lowered to open the cleaning region, so that the transfer means 20 can access the spinner table 34.

  The cleaning liquid supply means includes, for example, a cleaning water jet nozzle disposed above the spinner table 32, and a cleaning liquid delivery means including a tank and a pump (both not shown). This cleaning liquid supply means supplies a cleaning liquid such as cleaning water to the semiconductor wafer 50 held on the spinner table 32.

  The high-pressure air supply means includes air delivery means such as an air compressor or an air tank, and an air nozzle (not shown) disposed above the spinner table 32. This high-pressure air supply means dries the cleaned semiconductor wafer 50 by jetting air.

  The spinner cleaning apparatus 30 having the above-described configuration is cleaned by spraying cleaning water onto the semiconductor wafer W while rotating the semiconductor wafer 50 after grinding to remove contamination and cleaning the semiconductor wafer 50. Dry. The semiconductor wafer 50 thus cleaned and dried is sucked and held from below by the workpiece holder 222 of the transfer means 20 and picked up from the spinner table 32. Injects air from the upper side to the outer peripheral portion of the semiconductor wafer 50 to correct the warp.

  Here, the air injection means 40 shown in FIGS. 3 and 4 will be described in detail with reference to FIG. FIG. 5 is a cross-sectional view for explaining operations of the air ejecting means 40 and the conveying means 20 according to the present embodiment.

  As described above, the air ejecting means 40 constitutes the workpiece transport device according to the present embodiment together with the transport means 20, and the semiconductor wafer 50 is preferably attracted and held by the workpiece holding portion 22 of the transport means 20. Help you to do it.

  As shown in FIG. 3, the air ejecting means 40 is disposed on the spinner table 32 as a part of the spinner cleaning device 30, for example. As shown in FIGS. 3 and 4, the air injection means 40 includes a plurality of (for example, eight) air injection nozzles 42 arranged at substantially equal intervals along the outer peripheral portion of the semiconductor wafer 50, and the plurality of these air injection nozzles 42. A nozzle support portion 44 for supporting the air injection nozzle 42; an elevating means 46 for raising and lowering the nozzle support portion 44; an air delivery means 48 for supplying high-pressure air to the air injection nozzle 42, comprising an air compressor and an air tank; , Provided.

  For example, eight air injection nozzles 42 (hereinafter simply referred to as “nozzles 42”) are arranged on the outer periphery of the nozzle support portion 44. Each nozzle 42 is attached to the nozzle support portion 44 with the injection port facing downward in the vertical direction. The nozzle 42 injects, for example, high-pressure air supplied from the air delivery means 48 via the air supply pipes 45 and 43 downward. The air injection pressure by the nozzles 42 is, for example, 200 L / s in flow rate (for example, about 0.5 MPa at the pump portion of the air delivery means 48), and the injection pressures are approximately the same in each nozzle 42. It has been adjusted. Moreover, although the air injection time by the nozzle 42 is about 2-3 seconds, for example, it is not limited to this example.

  As shown in FIG. 5, the nozzle 42 warps upward toward the outer peripheral portion of the semiconductor wafer 50 placed on the spinner table 32 as shown in FIG. It is possible to correct and flatten the outer peripheral portion.

  Further, as shown in FIG. 4, the eight nozzles 42 are arranged at predetermined intervals in the circumferential direction of the nozzle support portion 44 along the outer peripheral portion of the semiconductor wafer 50. As a result, air can be evenly jetted by the eight nozzles 42 to the outer peripheral portion of the upper surface of the semiconductor wafer 50 placed on the spinner table 32, and the warpage of the semiconductor wafer 50 can be corrected evenly. However, the number and arrangement of the nozzles 42 are not limited to the illustrated example. For example, the number of nozzles 42 may be increased by narrowing the installation interval of the nozzles 42. This is considered to be more effective in terms of correcting the warp of the semiconductor wafer 50, but it is not always efficient in terms of cost and the like, so it cannot be said that it is generally good. Further, as described above, the arrangement of the nozzles 42 is preferably provided symmetrically at a predetermined interval in the circumferential direction on the outer peripheral portion of the nozzle support portion 44, but is not limited to this example.

  The nozzle support portion 44 includes a disk-shaped support plate 441 having substantially the same diameter as the semiconductor wafer 50, and a plurality of nozzles 42 for fixing each nozzle 42 to a U-shaped notch 441a formed on the support plate 441. Nozzle mounting member 42. The outer diameter of the support plate 441 is slightly smaller than the diameter of the circular through hole 38 a formed in the upper spinner cover 38. Therefore, the nozzle support portion 44 can move up and down through the through hole 38 a of the upper spinner cover 38.

  The elevating means 46 elevates and lowers the nozzle support portion 44 between a retracted position located near the through hole 38 a of the upper spinner cover 38 and an injection position located near the spinner table 32. The lifting means 46 includes, for example, an air cylinder 461, a piston rod 462 extending downward from the air cylinder 461, and a support member 463 that supports the air cylinder 461 and is fixed to the support base 18. The tip of the piston rod 462 is connected to the central portion of the support plate 441 of the nozzle support portion 44.

  As shown in FIG. 5, the lifting / lowering means 46 having such a configuration normally moves the nozzle support portion 44 up by the operation of the air cylinder 461 and positions it at the retracted position where it is retracted from the periphery of the spinner table 32. Thereby, for example, at the time of spinner cleaning, the nozzle support portion 44 can be retracted so as not to interfere with the cleaning operation, and the nozzle 42 can be prevented from being contaminated by droplets or the like due to spinner cleaning.

  On the other hand, when the semiconductor wafer 50 is to be sucked and held by the workpiece holding portion 22 of the transfer means 20, the lifting means 46 lowers the nozzle support portion 44 by the operation of the air cylinder 461 as shown in FIG. Thus, it is positioned at an ejection position directly above the semiconductor wafer 50 placed on the spinner table 32. The center of the through hole 38 a of the upper spinner cover 38, the center of the support plate 441 of the nozzle support portion 44, and the center of the piston rod 462 of the elevating means 46 are on the rotation axis of the spinner table 32. For this reason, by positioning the nozzle support portion 44 at the spray position, each nozzle 42 can be accurately placed directly above the outer peripheral portion of the semiconductor wafer 50 placed on the spinner table 32.

  In this way, the lifting means 46 lowers the nozzle support portion 44 and places it at the injection position only when the semiconductor wafer 50 is picked up from the spinner table 32, and at other times the nozzle support portion 44 is moved upward. Retreat to the retreat position.

  The air ejecting means 40 having the above-described structure allows the nozzle support part 44 to be moved by the lifting / lowering means 46 when the work piece holding part 22 sucks and holds the semiconductor wafer 50 placed on the spinner table 32 from below. It arrange | positions at the injection position shown in FIG. And when the nozzle support part 44 exists in this injection position, as shown in the partial enlarged view of FIG. 5, air is injected from the upper side to the outer peripheral part of the semiconductor wafer 50 by predetermined time by each nozzle 42. FIG. As a result, the warpage of the outer peripheral portion of the semiconductor wafer 50 is corrected, and the lower surface of the outer peripheral portion of the semiconductor wafer 50 is brought into close contact with the upper surface of the workpiece holder 22 that supports the semiconductor wafer 50 from below. Can do. For this reason, the outer periphery of the semiconductor wafer 50 can be favorably sucked and held without causing air leakage by the suction pad 24 disposed on the upper surface of the workpiece holding portion 22.

  Next, the semiconductor wafer placed on the spinner table 32 using the workpiece transfer device (the transfer means 20 and the air injection means 40) of the grinding apparatus 1 configured as described above with reference to FIG. A method of conveying 50 to the cassette 12 will be described with reference to FIG. In addition, FIG. 6 is a flowchart which shows the workpiece conveyance method using the workpiece conveyance apparatus of the grinding apparatus 1 concerning this embodiment.

  As shown in FIG. 6, first, in step S12, the outer peripheral portion of the semiconductor wafer 50 placed on the spinner table 32 is supported from below by the workpiece holding unit 22 of the transport means 20 (step S12; support). Process).

  Specifically, first, after the semiconductor wafer 50 is cleaned by the spinner cleaning device 30, the support table 34 is lowered and positioned at the non-operating position, and the vacuum suction of the spinner table 32 by the vacuum chuck is released. In this state, the cleaned semiconductor wafer 50 is placed on the spinner table 32 with the ground processing surface facing upward. Next, the workpiece holding part 22 (C-shaped hand) of the conveying means 20 is horizontally moved at the height of the support part 324 of the spinner table 32 and is disposed below the semiconductor wafer 50 (two-dot line in FIG. 5). State shown by). Thereafter, the workpiece holder 22 is raised to a height at which the upper surface of the workpiece holder 22 contacts the lower surface of the semiconductor wafer 50. Thereby, the outer peripheral part of the semiconductor wafer 50 is supported from the lower side by the workpiece holding part 22 (state shown by a solid line in FIG. 5). However, since the outer peripheral portion of the semiconductor wafer 50 extends upward, a part or all of the lower surface of the outer peripheral portion of the semiconductor wafer 50 is not in close contact with the upper surface of the workpiece holder 22.

  Next, in step S14, the nozzle support 42 to which the plurality of nozzles 42 are attached is lowered (step S14; nozzle lowering step). Specifically, the nozzle support member 42 is lowered from the retracted position around the upper spinner cover 38 (position indicated by the two-dot chain line in FIG. 5) by the lifting / lowering means 46 of the air ejecting means 40, and directly above the semiconductor wafer 50. It is positioned at the injection position (the position indicated by the solid line in FIG. 5). In addition, this step S14 may be performed before the said step S12.

  Further, in step S16, air is injected from the nozzle 42 to the outer peripheral portion of the semiconductor wafer 50 (step S16; air injection step). By this air injection, the outer peripheral portion of the semiconductor wafer 50 that is warped upward is pressed and flattened by the pressure of the air. As a result, the lower surface of the outer peripheral portion of the semiconductor wafer 50 is brought into close contact with the upper surface of the workpiece holding unit 22. The air injection is continued for a predetermined time (for example, several seconds) until the suction holding by the suction pad 24 in the next step S18 is completed.

  Thereafter, in step S18, the outer peripheral portion of the semiconductor wafer 50 brought into close contact with the workpiece holding unit 22 is sucked and held by the suction pad 24 of the workpiece holding unit 22 (step S18; suction holding step). Specifically, the outer peripheral portion of the semiconductor wafer 50 is sucked and held by a plurality of suction pads 24 provided on the workpiece holding portion 22 by negative pressure. At this time, since the lower surface of the outer peripheral portion of the semiconductor wafer 50 is in close contact with the upper surface of the workpiece holding portion 22 in step S16, the outer peripheral portion of the semiconductor wafer 50 can be reliably sucked and held without causing air leakage. . Furthermore, since the workpiece holding unit 22 holds the circuit surface side of the semiconductor wafer 50 to which the tape is attached and does not contact the ground processing surface, the processing surface is not damaged. It should be noted that the evacuation of the suction pad 24 may be continuously performed before the air injection in step S18, or may be started at the same timing as the air injection.

  Furthermore, in step S20, the nozzle support part 42 is raised (step S14; nozzle raising step). Specifically, the nozzle support member 42 is raised from the injection position by the elevating means 46 of the air injection means 40 and is positioned at the retracted position. As a result, the nozzle support member 42 is retracted upward, so that the nozzle support member 42 does not interfere with the transfer in the subsequent pick-up and transfer process of the semiconductor wafer 50.

  Next, in step S22, the semiconductor wafer 50 is picked up by the workpiece holding unit 22 that holds the semiconductor wafer 50 by suction (step S22; pickup process). Specifically, the workpiece holding unit 22 in a state where the semiconductor wafer 50 is held by suction is raised by the moving unit 28 of the transfer unit 20. As a result, the workpiece holding unit 22 can pick up the semiconductor wafer 50 held by suction from the spinner table 32.

  Further, in step S24, the workpiece holder 22 holding the semiconductor wafer 50 by suction is moved, and the semiconductor wafer 50 is transferred to the vicinity of the cassette 12 (step S24; transfer process). Specifically, the workpiece holding unit 22 that holds the semiconductor wafer 50 by suction is moved in the horizontal and vertical directions by the moving means 28. Thereby, the semiconductor wafer 50 can be conveyed from the spinner cleaning apparatus 30 to the vicinity of the cassette 12.

  After that, in step S26, the workpiece holding unit 22 is inverted about the connecting shaft 26 by the support rotating unit 286 of the moving unit 28, and the suctioned and held semiconductor wafer 50 is inverted (step S26; inversion step). ). As a result, the workpiece holding portion 22 is positioned on the upper side of the semiconductor wafer 50, and the semiconductor wafer 50 is held with the circuit surface facing upward (the ground processing surface facing downward).

  Next, in step S28, the semiconductor wafer 50 is accommodated in the cassette 12 with the circuit surface of the semiconductor wafer 50 facing upward (step S28; accommodation process). At this time, since the workpiece holder 22 holds the semiconductor wafer 50 on the lower side, the semiconductor wafer 50 can be easily placed in the slot of the cassette 12 with the circuit surface facing upward. The workpiece conveying method according to the present embodiment is completed through the steps described above.

  In the above, the workpiece conveyance apparatus of the grinding apparatus 1 concerning this embodiment and the workpiece conveyance method using the same were demonstrated. As described above, the workpiece transfer apparatus and the workpiece transfer method according to the present embodiment do not permanently flatten the warpage of the outer peripheral portion of the semiconductor wafer 50 by the air injection means 40. Only when the outer peripheral portion of the semiconductor wafer 50 is sucked and held from below by the workpiece holding portion 22 (C-shaped hand) of the transport means 20 (robot pick), the warpage of the outer peripheral portion of the semiconductor wafer 50 is corrected. Flatten.

  In other words, in this embodiment, the nozzle 42 is brought close to the outer peripheral portion of the semiconductor wafer 50 by the time the workpiece holding portion 22 is inserted below the semiconductor wafer 50 and the outer peripheral portion of the semiconductor wafer 50 is sucked. It is moved to the position, and air is jetted from the nozzle 42 slightly before or at the same timing as the workpiece holding portion 22 sucks the outer peripheral portion of the semiconductor wafer 50. By this air injection, the outer peripheral portion of the semiconductor wafer 50 is flattened, and the outer peripheral portion of the semiconductor wafer 50 can be suitably sucked and held by the workpiece holding portion 22.

  In order to confirm whether or not the outer peripheral portion of the semiconductor wafer 50 has been reliably sucked by the workpiece holder 22, the grinding apparatus 1 is a sensor (not shown) that measures the negative pressure acting on the suction pad 24. And an adsorption state determination unit (not shown) that determines whether the adsorption state of the semiconductor wafer 50 is appropriate based on whether or not the absolute value of the measured negative pressure is larger than a predetermined threshold value set in advance. It has. When the absolute value of the measured negative pressure is equal to or greater than the threshold value, the suction state determination unit determines that the semiconductor wafer 50 is normally sucked and permits the semiconductor wafer 50 to be picked up and transferred. On the other hand, when the absolute value of the negative pressure is less than the threshold value, the suction state determination unit determines that the semiconductor wafer 50 is not normally sucked and has an error, and outputs an error display to the monitor of the grinding apparatus 1. Then, picking up and transporting the semiconductor wafer 50 is prohibited.

  As described above, according to the workpiece transfer apparatus and the workpiece transfer method of the present embodiment, even when the outer peripheral portion of the semiconductor wafer 50 that is the workpiece is warped, the air injection means 40 Since the warpage of the outer peripheral portion of the semiconductor wafer 50 can be flattened, the semiconductor wafer 50 can be reliably sucked and held by the workpiece holding portion 22.

  Furthermore, since the workpiece holding unit 22 holds and conveys the circuit surface side of the semiconductor wafer 50 to which the tape is attached, the processed surface of the ground semiconductor wafer 50 is not damaged. In addition, when the semiconductor wafer 50 is accommodated in the cassette 12 by the workpiece holder 22, the semiconductor wafer 50 can be easily placed in the slot with the circuit surface of the semiconductor wafer 50 facing upward.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are of course within the technical scope of the present invention. Understood.

  For example, in the above-described embodiment, the example of the semiconductor wafer 50 is described as a specific example of the workpiece, but the present invention is not limited to such an example. Workpieces include, for example, various semiconductor substrates, sapphire substrates, glass materials, ceramic materials, metal materials, synthetic resin materials such as plastics, or electronic material substrates for forming magnetic heads, laser diode heads, etc. It may be. Further, the shape of the workpiece may be an arbitrary shape such as a substantially elliptical plate or a substantially rectangular plate shape other than the substantially disk shape. Furthermore, according to the shape of the workpiece, the shapes of the workpiece holding portion 22, the nozzle support portion 44 of the air injection means 40, the table 32, and the like can be changed.

  Moreover, although the said embodiment demonstrated the workpiece conveying apparatus (conveying means 20 and the air injection means 40) provided in the grinding apparatus 1, this invention is not limited to this example. For example, the workpiece transfer device may be provided in a polishing device that polishes (for example, CMP) the workpiece with a polishing pad and a polishing liquid.

  Moreover, in the said embodiment, although the workpiece conveyance apparatus was used in order to convey the workpiece mounted on the spinner table 32 of the spinner cleaning apparatus 30, this invention is not limited to this example. For example, the workpiece conveying device can be applied to a case where a workpiece placed on various tables is picked up and conveyed to another place in a grinding device, a polishing device, a cutting device, or the like.

  Moreover, in the said embodiment, although the workpiece holding part 22 of the conveyance means 20 was comprised by the C-shaped hand, it is not limited to this example. The workpiece holding part 22 may have an arbitrary shape corresponding to the shape of the workpiece to be conveyed, such as a U shape, a V shape, or a ring shape.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a workpiece transfer device that can suitably hold and transfer a workpiece such as a semiconductor wafer whose outer peripheral portion is warped, and a grinding device equipped with the workpiece transfer device.

It is a perspective view showing the whole grinding device composition concerning a 1st embodiment of the present invention. It is a perspective view which shows the conveyance means concerning the embodiment. It is a perspective view which shows the spinner washing | cleaning apparatus and air injection means concerning the embodiment. It is a top view which shows the air injection means concerning the embodiment. It is sectional drawing for demonstrating operation | movement of the air injection means and conveyance means concerning the embodiment. It is a flowchart which shows the workpiece conveyance method using the workpiece conveyance apparatus of the grinding device concerning the embodiment.

Explanation of symbols

1 Grinding machine 12 Cassette 20 Transport means (robot pick)
22 Workpiece holding part (C-shaped hand)
24 suction pad 28 moving means 30 spinner cleaning device 32 spinner table 34 support table 40 air injection means 42 air injection nozzle 44 nozzle support member 46 elevating means 50 semiconductor wafer 222 arcuate portion

Claims (7)

A workpiece transfer device for transferring a workpiece placed on a table;
A workpiece holding portion for supporting an outer peripheral portion of the workpiece placed on the table from below;
Air injection means for injecting air from above to the outer peripheral portion of the workpiece placed on the table;
A suction pad provided on the workpiece holding portion and holding the outer periphery of the workpiece by suction;
Moving means for moving the workpiece holding portion that holds the workpiece by suction with the suction pad;
A workpiece conveying device comprising: The air injection means includes
A plurality of air injection nozzles arranged at substantially equal intervals along the outer periphery of the workpiece;
A nozzle support for supporting the plurality of air injection nozzles;
Elevating means for elevating and lowering the nozzle support;
The workpiece conveyance device according to claim 1, comprising: The workpiece holding portion is formed in a substantially C-shaped flat plate shape having a pair of opposing arc-shaped portions, and a base portion that connects the pair of arc-shaped portions is connected to the moving means,
The suction pad is disposed in each of the arc-shaped portions at a position approximately symmetrical about an axis passing between the middle of the pair of arc-shaped portions and the base portion, at least two spaced apart from each other. The workpiece conveying apparatus according to claim 1, wherein The table is
A main table having an adsorption holding surface for adsorbing and holding a central portion of the workpiece;
A support table having a support surface for supporting the outer periphery of the workpiece;
Support table positioning means for selectively positioning the support surface of the support table at a working position substantially flush with or slightly lower than the suction holding surface of the main table and a non-working position retracted downward from the working position. When;
With
The workpiece holding portion supports an outer peripheral portion of the workpiece placed on the main table from below when a support surface of the support table is in the non-operation position. A workpiece transfer apparatus according to any one of claims 1, 2, and 3.   A spinner cleaning apparatus comprising the workpiece transfer apparatus according to any one of claims 1, 2, 3, and 4.   A grinding apparatus comprising the spinner cleaning apparatus according to claim 5. A workpiece transfer method for transferring a workpiece placed on a table;
A supporting step of supporting an outer peripheral portion of the workpiece placed on the table from below by a workpiece holding portion;
An air injection step of injecting air from the upper side to the outer peripheral portion of the workpiece placed on the table and bringing the outer peripheral portion of the workpiece into close contact with the workpiece holding portion;
An adsorption holding step of adsorbing and holding an outer peripheral portion of the workpiece closely attached to the workpiece holding portion by an adsorption pad provided on the workpiece holding portion;
A transporting step of transporting the workpiece by moving the workpiece holding portion that holds the workpiece by suction;
A method of conveying a workpiece, comprising:

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