JP6985039B2 - Chuck table - Google Patents

Description

The present invention relates to a chuck table for holding a plate-shaped work.

In a plate-shaped work having an electrode on the surface of a disk-shaped substrate, for example, a resin layer covering the electrode is formed by spreading a heated and softened resin on the surface of the substrate, cooling and hardening the resin. Due to the shrinkage action of the resin due to this cooling, the resin layer side may be dented and the plate-shaped work may be warped. In the plate-shaped work in which the warp is generated, for example, the resin layer is ground with a grinding wheel to make the surface a uniform flat surface, and the electrodes are exposed on the surface (see, for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 2007-136636

However, since the portion where the plate-shaped work is warped is the outer peripheral portion of the plate-shaped work, a gap is likely to occur between the outer peripheral portion and the holding surface of the chuck table, and the plate-shaped work is not warped. The suction force is smaller than when the work is sucked and held. Then, when the plate-shaped work in which the warp is generated is sucked and held by the holding surface of the chuck table and the grinding wheel is brought into contact with the resin layer to perform grinding, the plate-shaped work is attempted to be peeled off from the holding surface of the chuck table. There is a problem that a force acts and the plate-shaped work cannot be sucked and held on the chuck table due to the force and the stress of the warped plate-shaped work.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable suction and holding of a warped plate-shaped work on a chuck table.

The present invention is a chuck table having a circular holding surface for holding a disk-shaped plate-shaped work, a porous plate formed in a disk shape and having one surface as a holding surface, and a porous plate thereof. A frame body having a recess for exposing the holding surface of the porous plate and accommodating the porous plate, having a suction groove on the bottom surface of the recess, and having a suction path penetrating the lower surface from the suction groove and communicating with the suction source. The outer peripheral portion of the porous plate is provided with a suction resistance reducing portion formed by a space directly communicating with the suction groove.

The suction resistance reducing portion preferably includes a ring-shaped recessed portion centered on the center of the porous plate, and the recessed portion is preferably directly communicated with the suction groove.

The porous plate is composed of a disk-shaped central porous plate and a ring porous plate surrounding the central porous plate, and the ring porous plate is formed to be thinner than the central porous plate, and the ring porous plate is formed. It is preferable that a cavity is provided between the lower surface of the plate and the bottom surface of the recess, and the suction resistance reducing portion is configured by directly communicating the cavity with the suction groove.

The chuck table according to the present invention has a porous plate formed in a disk shape by a porous member and has one surface as a holding surface, and a recess for exposing the holding surface of the porous plate and accommodating the porous plate on the bottom surface of the recess. A frame body provided with a suction groove and a suction path penetrating the lower surface from the suction groove to communicate with the suction source, and the porous plate is provided with a suction resistance reducing portion on the outer peripheral side of the suction groove, so that the center of the porous plate is provided. The suction force acting on the holding surface on the outer peripheral side of the porous plate can be made larger than the suction force acting on the holding surface on the side through the suction resistance reducing portion, even if the plate-shaped work has a warp on the outer peripheral portion. The plate-shaped work can be reliably sucked and held on the holding surface of the porous plate.

Since the suction resistance reducing portion includes a ring-shaped recessed portion centered on the center of the porous plate, the suction resistance on the outer peripheral side can be made smaller than the suction resistance at the center of the porous plate, and the outer peripheral side of the porous plate can be reduced. The suction action on the holding surface of the can be strengthened.

The porous plate is composed of a disk-shaped central porous plate and a ring porous plate surrounding the central porous plate, and the ring porous plate has a porosity larger than the porosity of the central porous plate and is ring porous. Since the plate is configured as the suction resistance reducing portion, the suction action can be made stronger on the holding surface of the ring porous plate than on the holding surface of the central porous plate, and a plate-shaped work with a warp on the outer peripheral portion can be reliably performed. Can be sucked and held.

It is an exploded perspective view which shows the structure of the 1st example of a chuck table. It is a perspective view which looked at the porous plate from the lower side. It is sectional drawing which shows the structure of the 1st example of a chuck table. It is sectional drawing which shows the structure of the 2nd example of a chuck table. (A) is a plan view of the porous plate of the second example of the chuck table as viewed from above. (B) is a plan view of a modified example of the porous plate of FIG. 4 as viewed from above. It is sectional drawing which shows the structure of the 3rd example of a chuck table. (A) is a plan view of the porous plate of the third example of the chuck table as viewed from above. (B) is a plan view of a modified example of the porous plate of FIG. 6 as viewed from above. It is sectional drawing which shows the structure of the 4th example of a chuck table. It is sectional drawing which shows the structure of the 5th example of a chuck table. It is sectional drawing which shows the structure of the 6th example of a chuck table. It is sectional drawing which shows the structure of the 7th example of a chuck table.

The chuck table 1 shown in FIG. 1 is a first example of a chuck table for sucking and holding a disk-shaped plate-shaped work. The chuck table 1 is a frame body having a porous plate 2 formed of a porous member in a disk shape and having one surface as a holding surface 20 and a recess 31 for exposing the holding surface 20 of the porous plate 2 and accommodating the porous plate 2. It is equipped with 3.

The frame body 3 has a ring-shaped convex portion 36 for fitting the outer peripheral surface 21 of the porous plate 2 without a gap. The inner region of the convex portion 36 is a concave portion 31 formed according to the shape of the porous plate 2. That is, the inner diameter of the concave portion 31 of the frame body 3 is formed to be slightly larger than the outer diameter of the porous plate 2, and the porous plate 2 can be fitted into the concave portion 31. The bottom surface 32 of the recess 31 is formed on a flat surface in order to horizontally fix the bottom surface 22 of the porous plate 2.

The frame 3 includes a suction groove 33 formed on the bottom surface 32 of the recess 31, and a suction path 35 that penetrates the suction groove 33 to the lower surface 34 and communicates with the suction source 5 (shown in FIG. 3). The suction groove 33 shown in the present embodiment is formed concentrically with the ring-shaped convex portion 36. By generating a negative pressure in the suction groove 33 through the suction path 35, the suction force can be transmitted to the porous plate 2 fitted in the recess 31 and the suction action can be exerted on the holding surface 20. The number and positions of the suction paths 35 are not limited to the configuration shown in this embodiment.

The holding surface 20 of the porous plate 2 is formed in a shape similar to that of the plate-shaped work, and has substantially the same area as the plate-shaped work. As shown in FIG. 2, the lower surface 22 of the porous plate 2 is provided with a suction resistance reducing portion 4 on the outer peripheral side of the circular suction groove 33. The suction resistance reducing portion 4 is configured to include a ring-shaped recessed portion 40 centered on the center of the porous plate 2. The recessed portion 40 shown in the illustrated example is composed of cavities. The position of the suction resistance reducing portion 4 is outside the suction groove 33 and corresponds to the position of the outer peripheral portion of the plate-shaped work held on the holding surface 20 of the porous plate 2. The suction resistance reducing unit 4 can make the suction resistance of the outer peripheral portion smaller than the suction resistance of the central portion of the porous plate 2 shown in FIG. 1, and can strengthen the suction action on the holding surface 20 on the outer peripheral side of the porous plate 2.

When the porous plate 2 is housed in the frame 3, for example, an adhesive is applied to the bottom surface 32 of the recess 31, the porous plate 2 is fitted into the recess 31, and the bottom surface 22 of the porous plate 2 is adhesively fixed on the bottom surface 32. Let me. As a result, as shown in FIG. 3, a chuck table 1 in which the porous plate 2 and the frame body 3 are integrated is formed. The chuck table 1 is mounted on, for example, a grinding device (not shown).

When the plate-shaped work is sucked and held by the chuck table 1, the suction force of the suction source 5 is transmitted to the porous plate 2 through the suction path 35. At this time, of the suction force transmitted to the porous plate 2 and acting on the holding surface 20, the suction force acting on the holding surface 20 on the center side of the porous plate 2 is larger than the suction force acting on the holding surface 20 on the outer peripheral side of the porous plate 2 through the suction resistance reducing portion 4. The suction force acting on the holding surface 20 becomes large. Therefore, even if the outer peripheral portion of the plate-shaped work to be sucked and held by the chuck table 1 is warped, a suction force larger than the stress due to the warp of the plate-shaped work can be exerted on the holding surface 20 on the outer peripheral side of the porous plate 2. This makes it possible to reliably suck and hold the plate-shaped work on the holding surface 20. As a result, when the plate-shaped work held on the chuck table 1 is ground by, for example, a grinding wheel, there is no possibility that the plate-shaped work will come off from the chuck table 1 and suction holding will not be possible.

The other embodiments will be described below. The same components as those of the chuck table 1 are designated by a common reference numeral and the description thereof will be omitted.

The chuck table 1A shown in FIG. 4 is a second example of the chuck table, and includes a disk-shaped porous plate 2A, and a suction resistance reducing portion 4a is provided on the holding surface 20 on the outer peripheral side of the porous plate 2A. Like the porous plate 2A shown in FIG. 5A, the suction resistance reducing portion 4a is configured to include a ring-shaped recessed portion 41 (shaded and shown) centered on the center of the porous plate 2A. Similar to the chuck table 1 described above, the suction resistance on the outer peripheral side can be made smaller than the suction resistance at the center of the porous plate 2A, and the suction action on the holding surface 20 on the outer peripheral side of the porous plate 2A can be strengthened.

The suction resistance reducing portion 4a is configured to include a series of ring-shaped recessed portions 41, but is not limited to such a configuration. For example, as in the porous plate 2A shown in FIG. 5B, the suction resistance reducing portion 4a'has a plurality of holes 42 (shaded) arranged so as to form a ring as a whole along the peripheral edge of the porous plate 2A. It may be configured to include (shown in the figure).

The chuck table 1B shown in FIG. 6 is a third example of the chuck table, and includes a disk-shaped porous plate 2B, and a suction resistance reducing portion 4b on the holding surface 20 on the outer peripheral side of the porous plate 2B. As shown in FIG. 7A, the suction resistance reducing portion 4b has a ring-shaped recessed portion 41 centered on the center of the porous plate 2B and a ring-shaped inner recessed portion 43 formed inside the recessed portion 41. It is composed including and. The width of the inner recess 43 in the illustrated example is narrower than the width of the recess 41. Further, the depth of the inner recessed portion 43 is shallower than the depth of the recessed portion 41.

In the chuck table 1B, by forming double large and small cavities on the holding surface 20 on the outer peripheral side of the porous plate 2B, the suction resistance of the holding surface 20 can be gradually reduced from the center to the outer peripheral side. can. That is, the suction resistance of the portion where the inner recessed portion 43 is formed can be made smaller than the center of the holding surface 20, and the suction resistance of the portion where the recessed portion 41 is formed can be made smaller than the portion where the inner recessed portion 43 is formed. It can be made smaller, and the suction action on the holding surface 20 on the outermost peripheral side of the porous plate 2B can be made the strongest.

The suction resistance reducing portion 4b has a configuration including a series of ring-shaped recessed portions 41 and an inner recessed portion 43, but is not limited to such a configuration. For example, as in the porous plate 2B shown in FIG. 7B, the suction resistance reducing portion 4b'is arranged along the peripheral edge of the porous plate 2B so as to form a ring as a whole. The configuration may include a plurality of small holes 45 (shown with shading) arranged in a ring shape as a whole inside the plurality of large holes 44 (shown with shading). In the third example, large and small cavities and large and small holes are formed in a double ring shape on the holding surface 20 on the outer peripheral side of the porous plate 2B, but the configuration is not particularly limited to that of the present embodiment and is triple. It may be formed as described above.

The chuck table 1C shown in FIG. 8 is a fourth example of the chuck table, and includes a disk-shaped porous plate 2C, and a suction resistance reducing portion 4c on the holding surface 20 on the outer peripheral side of the porous plate 2C. The suction resistance reducing portion 4c is configured to include a recessed portion 6 having a substantially L-shaped cross section formed on the lower surface 22 of the porous plate 2C. The recess 6 is composed of a ring-shaped outer recess 6a and a ring-shaped inner recess 6b communicating with the inside of the outer recess 6a. The inner recess 6b has a height lower than that of the outer recess 6a, and one end of the inner recess 6b communicates with the suction groove 33 of the frame body 3. In the chuck table 1C, since the suction resistance reducing portion 4c and the suction groove 33 communicate with each other, the suction resistance can be effectively reduced by the suction resistance reducing portion 4c, and the holding surface 20 on the outer peripheral side of the porous plate 2C can be effectively reduced. It is possible to strengthen the suction action in.

The chuck table 1D shown in FIG. 9 is a fifth example of the chuck table, and includes a porous plate 2D having an inverted conical shape, and a suction resistance reducing portion 4d on a holding surface 20 on the outer peripheral side of the porous plate 2D. The porous plate 2D has an inverted conical surface 23 from its outer peripheral surface 21 to its lower surface 22. The suction resistance reducing portion 4d is configured to include a recessed portion 7 formed between the inverted conical surface 23 and the bottom surface 32 of the recessed portion 31. The recessed portion 7 communicates with the suction groove 33 of the frame body 3. According to this configuration, the suction resistance can be effectively reduced by the suction resistance reducing unit 4d, and the suction action on the holding surface 20 on the outer peripheral side of the porous plate 2D can be strengthened.

The chuck table 1E shown in FIG. 10 is a sixth example of the chuck table, and includes a disk-shaped porous plate E, and a suction resistance reducing portion 4e is provided on the holding surface 20 on the outer peripheral side of the porous plate 2E. The suction resistance reducing portion 4e has an outer through hole 8a that penetrates the upper and lower surfaces in the thickness direction in a ring shape centered on the center of the porous plate 2E, and an inner penetration that penetrates the upper and lower surfaces in the thickness direction inside the outer through hole 8a. It is configured to include the hole 8b. The width of the inner through hole 8b in the illustrated example is narrower than the width of the outer through hole 8a. In the chuck table 1E, the suction resistance can be effectively reduced by the suction resistance reducing portion 4e, and the suction action on the holding surface 20 on the outer peripheral side of the porous plate 2E can be strengthened. In the illustrated example, large and small ring-shaped through holes are formed twice on the holding surface 20 on the outer peripheral side of the porous plate 2E, but the configuration is not limited to the configuration shown in the present embodiment, and the number is triple or more. It may be formed.

The chuck table 1F shown in FIG. 11 is a seventh example of a chuck table, and includes a porous plate 9 composed of two types of porous members. The porous plate 9 is composed of a disk-shaped central porous plate 90 and a ring porous plate 91 surrounding the central porous plate 90. The holding surface 90a of the central porous plate 90 and the holding surface 91a of the ring porous plate 91 are configured to be flush with each other. The ring porous plate 91 has a porosity (porosity) larger than the porosity (porosity) of the central porous plate 90. That is, the ring porous plate 91 has a coarser porous structure and better air permeability than the central porous plate 90. In the illustrated example, the thickness of the ring porous plate 91 is set to about ½ of the thickness of the central porous plate 90, and a ring shape is formed between the lower surface 91b of the ring porous plate 91 and the bottom surface 32 of the recess 31. The recessed portion 10 is formed, and the ring porous plate 91 is configured as a suction resistance reducing portion. The recess 10 communicates with the suction groove 33 of the recess 31. As described above, in the chuck table 1F, the suction action can be made stronger on the holding surface 91a of the ring porous plate 91 than on the holding surface 90a of the central porous plate 90, and the plate-like work having a warp on the outer peripheral portion can be surely made. Can be sucked and held. In the present embodiment, the ring-shaped recessed portion 10 is formed on the lower side of the ring porous plate 91 of the porous plate 9, but the recessed portion 10 may be omitted and the entire outer peripheral portion may be configured by the ring porous plate 91.

The embodiment of the present invention is not limited to the above embodiment, and may be appropriately modified as long as it does not deviate from the purpose of the technical idea of the present invention.

1,1A, 1B, 1C, 1D, 1E, 1F: Chuck table 2,2A, 2B, 2C, 2D, 2E: Porous plate 20: Holding surface 21: Outer peripheral surface 22: Bottom surface 23: Inverted conical surface 3: Frame 31: Concave 32: Bottom 33: Suction groove 34: Bottom 35: Suction path 36: Convex 4, 4a, 4b, 4c, 4d, 4e: Suction resistance reduction part 40, 41: Recess 42: Hole 43: Inner dent Part 44: Large hole 45: Small hole 5: Suction source 6: Recessed part 6a: Outer concave part 6b: Inner concave part 7: Recessed part 8a: Outer through hole 8b: Outer through hole 9: Porous plate 90: Central porous plate 91: Ring porous Plate 10: Recessed part

Claims (3)

A chuck table having a circular holding surface for holding a disk-shaped work piece.
A porous plate formed in a disk shape with a porous member and having one surface as a holding surface,
A frame body having a recess for exposing the holding surface of the porous plate and accommodating the porous plate, having a suction groove on the bottom surface of the recess, and having a suction path penetrating the lower surface from the suction groove and communicating with a suction source. And with
A chuck table provided with a suction resistance reducing portion formed by a space directly communicating with the suction groove on the outer peripheral portion of the porous plate. The suction resistance reducing unit, the saw including a porous plate ring-like recess portion around the center of the chuck table of claim 1, wherein configured to recess viewed portion communicated directly to the suction groove. The porous plate is composed of a disk-shaped central porous plate and a ring porous plate surrounding the central porous plate.
The ring porous plate is formed to be thinner than the central porous plate, and has a cavity between the lower surface of the ring porous plate and the bottom surface of the recess.
The chuck table according to claim 1 , wherein the suction resistance reducing unit is configured by directly communicating the cavity with the suction groove.

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