JP4808111B2 - Work chuck device - Google Patents

Description

  The present invention relates to a workpiece chuck for chucking various workpieces such as semiconductor wafers, glass wafers, and other ceramic wafers by vacuum suction when performing various processes such as peripheral polishing, surface polishing, or cleaning. It relates to the device.

  As this type of workpiece chuck device, those described in Patent Document 1, Patent Document 2, or Patent Document 3 are conventionally known. These chuck devices attach a work suction pad to a table surface of a chuck table provided with a suction hole leading to a vacuum source at a central position, and have a plurality of annular suction grooves leading to the suction hole on the suction pad. The workpiece is vacuum-sucked by these suction grooves.

  However, since the conventional chuck device has a structure in which a suction pad is directly attached to the table surface of the chuck table, it can be used only for a workpiece chuck that matches the size of the table surface. When these differ, it is necessary to prepare a chuck table having a size suitable for each workpiece. Further, when the table surface is damaged or a part of the chuck table (for example, the outer flange portion on the outer periphery of the main body in Patent Document 3) is broken, the entire chuck table has to be replaced.

  On the other hand, Patent Document 4 discloses a substrate transfer arm in which a planar sheet member (suction pad) is attached to a transfer arm via a spacer. However, since this is a configuration in which the spacer and the planar sheet member are attached to a plurality of locations on one transfer arm, the structure is complicated, the number of parts is increased, and the manufacturing cost is increased. Moreover, in order to cope with workpieces having different diameters, it is necessary to prepare a transfer arm in which the spacer and the planar sheet member are arranged in accordance with the workpiece.

  Therefore, the present applicant has proposed a workpiece chuck device capable of solving the above-described conventional problems in Japanese Patent Application No. 2005-334891. This is because the suction pad is attached to the table surface of the chuck table via the support plate. By using the support plate and the suction pad suitable for the workpiece diameter without changing the chuck table, A workpiece having a large diameter can be held by suction.

JP-A-6-246609 Japanese Patent Laid-Open No. 11-274280 JP 2005-311040 A JP 2000-133694 A

  However, the newly proposed chuck device has no problem when a support plate that is difficult to deform is used, but a relatively thin and elastically deformable support plate is disclosed in, for example, Patent Document 1 and Patent Document 2 described above. As described above, when the work is attached to an existing chuck table in which a work suction groove or a communication groove that communicates the suction groove with the central suction hole is directly formed on the table surface, the above is used. It is conceivable that the support plate is deformed at a portion such as a suction groove or a communication groove, and a suction gap is generated between the workpiece and the suction pad, thereby reducing the suction force.

  Accordingly, an object of the present invention is to further improve the above-mentioned newly proposed chuck device so that the support plate is not deformed even when a chuck table in which irregularities such as suction grooves and communication grooves are formed on the table surface is used. By configuring in this way, it is possible to prevent the formation of a gap between the workpiece and the suction pad due to the unevenness, and to reliably suck and hold the workpiece.

  In order to achieve the above object, according to the present invention, a cover plate for covering the table surface is attached to a table surface of a chuck table having a suction hole leading to a vacuum source in the center, Attach an elastic pad support plate having a size equal to or larger than that of the table surface, attach a work suction pad to the upper surface of the support plate, and center the cover plate and the support plate with the suction hole. A hole is formed, and an annular suction groove surrounding the central hole is formed in the suction pad, and at least one of the suction pad and the support plate is communicated with the suction groove and the central hole. There is provided a workpiece chuck device characterized in that a groove is formed.

In the present invention, the support plate and the suction pad can be configured to have the same outer shape and size.
Preferably, in the present invention, the support plate has a larger diameter than the table surface and the cover plate, and is attached in a state in which the outer peripheral portion protrudes from the table surface and the cover plate. That is, a flexure is formed.

In the present invention, an annular gap may be formed by non-adhering the cover plate and the support plate to each other at the outer periphery of the cover plate.
In this case, it is desirable that an annular and elastic slurry intrusion prevention member for preventing the slurry from entering the gap is provided between the cover plate and the support plate.

  According to the chuck device of the present invention, the cover plate for covering the table surface is attached to the table surface of the chuck table, and the pad support plate is attached through the cover plate. Even when unevenness such as the above is formed, the cover plate prevents the support plate from being deformed at the unevenness portion, and no gap is formed between the workpiece and the suction pad. Therefore, the work can be reliably sucked and held. Further, by selectively using a support plate and a suction pad that match the diameter of the workpiece while keeping the chuck table as it is, workpieces of various diameters can be sucked and held.

1 to 3 show a first embodiment of a workpiece chuck device according to the present invention. The chuck device 1A is attached to an outer peripheral polishing device for performing outer peripheral polishing on a thin plate-like workpiece 30 such as a semiconductor wafer, and holds the workpiece 30 being processed by vacuum suction. A disc-shaped chuck table 3 formed of a hard material such as a metal such as stainless steel or a hard synthetic resin is provided at the upper end, and a cover plate 4 is attached to a circular table surface 3 a on the upper surface of the chuck table 3. A pad support plate 5 is attached to the work plate, a work suction pad 6 is attached to the support plate 5, and the work 30 is vacuum sucked through the suction pad 6.
The main shaft 2 and the chuck table 3 may be integrally formed as illustrated, but they may be formed separately and connected to each other with screws.

  The cover plate 4 is a flat disk-shaped plate having substantially the same diameter as the table surface 3a, and is formed to a certain thickness by a material having elasticity, such as synthetic resin or metal, and the table. A double-sided adhesive sheet 8 is attached concentrically on the surface 3a. The cover plate 4 covers the table surface 3a to block irregularities on the table surface 3a. For example, as shown by a chain line in FIG. 3, the cover plate 4 has a workpiece suction groove and the suction surface on the table surface 3a. When a concave groove 3b such as a communication groove that communicates the groove with the suction hole in the center of the table is formed, the concave and convex portions on the table surface 3a are blocked by covering the concave groove 3b, and the concave groove 3b This is to prevent the support plate 5 from being deformed at this portion.

On the other hand, the support plate 5 is a flat disk-shaped plate having a certain thickness formed so as to be elastically deformable by the same material as the cover plate 4, and includes a table surface 3 a and a cover plate 4. It has a large diameter and is concentrically attached on the cover plate 4 by a double-sided adhesive sheet 9. Therefore, the outer peripheral portion of the support plate 5 is in a state of protruding from the table surface 3 a and the cover plate 4. Further, in the outer peripheral portion of the cover plate 4, these plates 4, 5 are not adhered to each other without interposing the adhesive sheet 9 between the cover plate 4 and the support plate 5. An annular gap 10 is interposed between the plates 4 and 5 to cause the support plate 5 to be elastically deformed following the bending of the work 30. With this configuration, the workpiece 30 is formed on the outer peripheral portion of the support plate 5 by the protruding portion 12a that protrudes around the cover plate 4 and the non-adhesive portion 12b that is the portion facing the gap 10 inside. A flexible portion 12 that is elastically deformable following the deformation of the workpiece during polishing is formed.
Although the thickness of the support plate 5 is slightly thicker than the cover plate 4 in the illustrated example, it may be the same as or thinner than the cover plate 4.

  On the upper surface of the support plate 5, the suction pad 6 having the same size as the support plate 5 is entirely attached by an adhesive means such as an adhesive or a double-sided adhesive sheet. The suction pad 6 is preferably attached to the support plate 5 in advance, and then the support plate 5 is attached to the cover plate 4 attached on the table surface 3a with the double-sided adhesive sheet 9.

  Thus, by attaching the support plate 5 to the table surface 3a via the cover plate 4, even if the groove 3b such as a suction groove is formed on the table surface 3a, the cover plate 4 can be used to form the groove 3b. As a result of being covered, the unevenness on the table surface 3a is blocked, and the support plate 5 is prevented from being deformed at the concave groove 3b.

  Inside the main shaft 2 and the chuck table 3, a suction hole 14 leading to a vacuum source (not shown) extends along the central axis L, and the tip of the suction hole 14 opens at the center position of the table surface 3a. . In addition, a center hole 15 communicating with the suction hole 14 is formed in the center of the double-sided adhesive sheets 8 and 9 and the cover plate 4, the support plate 5, and the suction pad 6 so as to penetrate these members. .

  The suction pad 6 is formed with a plurality of annular workpiece suction grooves 16 concentrically about the center hole 15, and the suction grooves 16 and the center hole 15. A plurality of communication grooves 17 are formed in the radial direction.

  In the above embodiment, the communication groove 17 is formed in the suction pad 6. However, the communication groove 17 may be formed in the support plate 5, or in both the suction pad 6 and the support plate 5. It may be formed.

  A circular workpiece 30 having a diameter larger than that of the support plate 5 and the suction pad 6 is vacuum-sucked through the suction pad 6 to the chuck device 1A having the above configuration. As shown in FIG. 4, the work 30 has bevel surfaces 30a and 30b and a circumferential end surface 30c on the outer peripheral portion. The bevel surfaces 30a and 30b and the circumferential end surface 30c are shown in FIGS. As shown in FIG. 6, outer periphery polishing is performed by the first to fourth four polishing members 20a, 20b, 20c, and 20d. At this time, the chuck table 3 is driven and rotated around the central axis L at a required speed by a driving source (not shown) connected to the main shaft 2.

  The first polishing member 20a polishes the bevel surface 30a on the front surface side of the workpiece 30, the second polishing member 20b polishes the bevel surface 30b on the back surface side, and the third and fourth polishing members 20c and 20d each have a circumference. The end face 30c is polished. The first polishing member 20a and the second polishing member 20b are disposed at positions facing each other with the chuck table 3 interposed therebetween, and the third polishing member 20c and the fourth polishing member 20d are the first polishing member. In the position between the member 20a and the second polishing member 20b, the chuck table 3 is disposed so as to face each other. However, one of the third polishing member 20c and the fourth polishing member 20d may be omitted.

  Each of the polishing members 20a, 20b, 20c, and 20d has an arc-shaped curved portion 21a formed on a hard base 21 made of metal, synthetic resin, ceramic, or the like, and a flexible polishing pad 22 on the inner surface of the curved portion 21a. A curved work surface 22a made up of the polishing pad 22 is formed by sticking, and the work surface 22a is pressed against the bevel surfaces 30a, 30b and the circumferential end surface 30c for polishing. Accordingly, the first polishing member 20a and the second polishing member 20b are disposed so that the generatrix of the work surface 22a is inclined in the direction along the bevel surfaces 30a and 30b on the front surface side and the back surface side, respectively. The third polishing member 20c and the fourth polishing member 20d are disposed with the generatrix of the work surface 22a directed in the vertical direction parallel to the circumferential end surface 30c.

  The polishing members 20a, 20b, 20c, and 20d are each supported by a support mechanism (not shown) so as to be movable. When the work 30 is carried into and out of the chuck table 3, the chuck table 3 is not disturbed. The work surface 22a is moved back to the retracted position away from the work position, and when the work 30 is polished, the work surface 22a is advanced to the illustrated processing position so as to come into contact with the bevel surfaces 30a, 30b and the circumferential end surface 30c. Further, during polishing, in order to change the position of contact with the workpiece, it moves slowly in a direction along the bevel surfaces 30a and 30b and the circumferential end surface 30c.

  When the outer periphery is polished, a downward processing pressure is applied to the workpiece 30 by the first polishing member 20a, and an upward processing pressure is applied by the second polishing member 20b. And in the part to which the upward process pressure acts on the workpiece | work 30, this workpiece | work 30 will bend upward and it will become easy to peel from the suction pad 6. FIG. On the other hand, in a portion where a downward working pressure is applied to the work 30, the work 30 bends downward, but is pressed against the suction pad 6 thereby, so that peeling is unlikely to occur.

  In order to prevent the peeling due to the bending of the workpiece 30 described above, it is basically sufficient to sufficiently increase the vacuum pressure for suction, but in addition, as described above, the support plate 5 can be elastically deformed. By forming and bending following the bending of the work 30, peeling of the work 30 from the suction pad 6 can be reliably prevented. In the above-described embodiment, the flexible portion 12 including the protruding portion 12 a and the non-adhesive portion 12 b is formed on the outer peripheral portion of the support plate 5, and the flexible portion 12 flexes following the bending of the workpiece 30. This prevents the formation of a gap between the work 30 and the suction pad 6, so that the work 30 does not peel from the suction pad 6. The degree of flexibility of the support plate 5 in this case does not necessarily have to be able to follow the bending of the work 30 completely without resistance, and the work 30 is not peeled in consideration of the suction force due to the vacuum pressure. As long as it can be elastically deformed while resisting the bending.

  The thickness of the support plate 5 meeting such conditions is, for example, about 0.1 to 10 mm, although it varies depending on the material, the size of the processing pressure, the type of the workpiece 30, and the like. Further, when the thickness of the support plate 5 is large to some extent, the support plate 5 is further bent in the flexible portion 12 by forming the thickness of the flexible portion 12 on the outer periphery of the support plate 5 thin. It can also be made easier.

  Thus, according to the chuck device having the above-described configuration, the support plate 5 is attached to the table surface 3a of the chuck table 3 via the cover plate 4, and the suction pad 6 is attached to the support plate 5, whereby the table surface 3a is attached to the table surface 3a. Even if the concave groove 3b such as the suction groove is formed, the concave plate 3b is covered by the cover plate 4 and the unevenness on the table surface 3a is blocked. Therefore, the support plate 5 is formed at the concave groove 3b. Therefore, the formation of a gap between the work 30 and the suction pad 6 by the concave groove 3b is surely prevented. In addition, since the flexible portion 12 of the support plate 5 is elastically deformed following the bending of the work 30 during polishing, formation of a gap due to the bending of the work 30 is also reliably prevented. In addition, by selectively using the support plate 5 and the suction pad 6 that match the diameter of the workpiece 30 while keeping the chuck table 3 as it is, workpieces of various diameters can be sucked and held.

FIG. 7 shows a second embodiment of the chuck device according to the present invention. The chuck device 1B of the second embodiment is different from the chuck device 1A of the first embodiment in that the cover plate 4 and the support plate 5 are different. In order to prevent the slurry from entering the gap 10 formed between the two plates 4 and 5, an annular slurry intrusion preventing member 23 is provided between the plates 4 and 5. The slurry intrusion prevention member 23 is made of an elastic material, and is disposed concentrically with the plates 4 and 5 in the annular gap 10 and is bonded by an adhesive means such as an adhesive or a double-sided adhesive sheet. At least one of these plates 4 and 5 is attached. Thereby, since the penetration | invasion of the slurry into the said gap 10 is prevented, peeling of the double-sided adhesive sheet 9 by contact with this slurry becomes difficult to occur. Further, it is possible to adjust the amount of bending of the support plate 5 in the direction of the cover plate 4 by using the elastic force of the slurry intrusion preventing member 23.
Since the configuration and operation other than those described above in the chuck device 1B of the second embodiment are substantially the same as those of the chuck device 1A of the first embodiment, the first embodiment is applied to the main same components. The same reference numerals as those in the embodiment are attached, and the description thereof is omitted.

  FIG. 8 shows a chuck device according to a third embodiment of the present invention. The chuck device 1C of the third embodiment is different from the chuck device 1A of the first embodiment in that the support plate 5 has a table surface 3a. And the cover plate 4 has substantially the same diameter, and the outer peripheral portion has no protruding portion 12a protruding around the table surface 3a and the cover plate 4. Therefore, the flexible portion 12 on the outer periphery of the support plate 5 is formed only by the non-adhesive portion 12 b facing the gap 10.

In the gap 10, a slurry intrusion preventing member for preventing the slurry from entering can be disposed as in the chuck device of the second embodiment.
Since the configuration and operation other than those described above in the chuck device 1C according to the third embodiment are substantially the same as those of the chuck device 1A according to the first embodiment, the main identical components are the same as those in the first embodiment. The same reference numerals are given and description thereof is omitted.

FIG. 9 shows a chuck device according to a fourth embodiment of the present invention. The chuck device 1D of the fourth embodiment is different from the chuck device 1A of the first embodiment in that the support plate 5 is a cover plate 4. By attaching the adhesive sheet 9 to the entire surface, the gap 10 as in the first to third embodiments is not formed between the plates 4 and 5. Therefore, the flexible portion 12 on the outer periphery of the support plate 5 is formed only by the protruding portion 12 a protruding from the table surface 3 a and the cover plate 4.
Since the configuration and operation of the chuck device 1D of the fourth embodiment other than those described above are substantially the same as those of the chuck device 1A of the first embodiment, the main same components are the same as those of the first embodiment. The same reference numerals are given and description thereof is omitted.

FIG. 10 shows a fifth embodiment of the chuck device according to the present invention. The chuck device 1E of the fifth embodiment is different from the chuck device 1A of the first embodiment in that the support plate 5 is a table surface 3a. And the cover plate 4 has substantially the same diameter and is attached to the cover plate 4 with a double-sided adhesive sheet 9 over the entire surface. Therefore, the flexible portion 12 as in the first to fourth embodiments is not formed on the outer periphery of the support plate 5. This embodiment is used under processing conditions that do not require the support plate 5 to be elastically deformed according to the bending of the work 30, and the work 30 is prevented from being peeled off by the suction force of the suction pad 6.
Since the configuration and operation of the chuck device 1E of the fifth embodiment other than those described above are substantially the same as those of the chuck device 1A of the first embodiment, the main identical components are the same as those of the first embodiment. The same reference numerals are given and description thereof is omitted.

In each of the above embodiments, the case of chucking a completely circular workpiece has been described. However, a V-shaped or U-shaped notch may be formed on a part of the outer periphery of the workpiece.
Further, as in the sixth embodiment shown in FIG. 11, when the linear orientation flat 30 d is formed on a part of the outer periphery of the work 30, the support plate 5 and the suction pad 6 are connected to the work 30. What is necessary is just to form it in a similar shape and smaller diameter than this workpiece | work 30. FIG. That is, it may be formed in a shape having the linear portion 25 at a part of the outer periphery. In this case, since the table surface 3a of the chuck table 3 and the cover plate 4 may remain circular, it is easy to cope with the workpiece 30 having such a special shape.

In each of the above embodiments, the double-sided adhesive sheets 8 and 9 are used to attach the cover plate 4 and the support plate 5, but instead of these double-sided adhesive sheets 8 and 9, an adhesive or other Adhesive means can also be used as appropriate.
Further, the chuck device of each of the above embodiments is installed in an outer peripheral polishing apparatus for performing outer peripheral polishing on a workpiece. However, the technique of the present invention is for performing various processes such as surface polishing or cleaning on a workpiece. The present invention can be similarly applied to a chuck device used in the above apparatus, a chuck device for conveying a workpiece, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view schematically showing a first embodiment of a chuck device according to the present invention, showing a state in which a workpiece is vacuum-adsorbed. FIG. 2 is a plan view of FIG. 1 in a state in which a workpiece is not vacuum-sucked. It is a partial expanded sectional view of FIG. It is the elements on larger scale which show an example of a workpiece | work. It is a principal part side view which shows notionally the state which performs outer periphery grinding | polishing to a workpiece | work. FIG. 6 is a plan view of FIG. 5. It is a fragmentary sectional view showing a chuck device of a 2nd embodiment. It is a fragmentary sectional view showing the chuck device of a 3rd embodiment. It is a fragmentary sectional view showing the chuck device of a 4th embodiment. It is a fragmentary sectional view showing the chuck device of a 5th embodiment. It is a top view which shows the chuck device of 6th Embodiment.

Explanation of symbols

1A, 1B, 1C, 1D, 1E Chuck device 3 Chuck table 3a Table surface 4 Cover plate 5 Support plate 6 Suction pad 10 Gap 12 Flexible portion 14 Suction hole 15 Center hole 16 Suction groove 17 Communication groove 23 Slurry intrusion prevention member 30 work

Claims (5)

  A cover plate for covering the table surface is attached to the table surface of the chuck table having a suction hole leading to a vacuum source in the center, and an elastic having a size equal to or larger than the table surface on the cover plate A support plate for a pad is attached, a work suction pad is attached to the upper surface of the support plate, a center hole leading to the suction hole is formed in the center of the cover plate and the support plate, and the center hole is formed in the suction pad. An chucking device for a work, wherein a ring-shaped suction groove is formed, and a communication groove is formed in at least one of the suction pad and the support plate to allow the suction groove and the center hole to communicate with each other. .   The chuck device according to claim 1, wherein the support plate and the suction pad have the same outer shape and size.   The support plate has a larger diameter than the table surface and the cover plate, and the outer peripheral portion protrudes from the table surface and the cover plate. The protruding outer peripheral portion forms a flexible portion. The chuck device according to claim 1, wherein the chuck device is provided.   4. The chuck device according to claim 1, wherein an annular gap is formed by non-bonding the cover plate and the support plate to each other at an outer peripheral portion of the cover plate. .   5. The annular and elastic slurry intrusion prevention member is provided between the cover plate and the support plate to prevent the slurry from entering the gap. Chuck device.

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