JP2524692Y2 - Workpiece holder - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used for polishing the surface of the object to be polished, which is a precision machined part such as a flat display glass, a reflector, a crystal oscillator, and a semiconductor wafer. The present invention also relates to an object-to-be-polished holder used by fixing an object to be polished to a polishing pad or a member that slides relatively to a polishing pad holding member that holds the polishing pad.

[Conventional technology]

Glass and lenses used for flat displays,
Alternatively, a semiconductor wafer or the like which is a substrate of an integrated circuit is polished by a polishing machine. The polishing machine usually has an upper surface plate and a lower surface plate, each of which rotates and rotates. A polishing pad is stuck on the lower surface plate, and the object to be polished is held on the upper surface plate by a holder for the object to be polished.

Then, the object to be polished is pressed against the polishing pad, and the two are rotated and slid while interposing an abrasive liquid therebetween, thereby polishing the object to be polished.

As shown in FIGS. 5 and 6, for example, a conventional workpiece holder has a circular or rectangular template 3 provided with a recess hole 31a into which a rectangular workpiece in plan view is fitted.
With one. A backing material 33 is attached to the surface of the template 31 on the side attached to the upper surface plate with an adhesive 32.

The backing material 33 has a recess 31 in the template 31.
A polymer foam suitable for holding the object to be polished fitted in a is used. When the object to be polished is strongly pressed through a liquid such as water, the backing material 33 adsorbs to the object to be polished and fixes the object to be polished.

The backing material 33 is lined with a support material 35 via an adhesive layer 34, and an adhesive layer 36 and a release paper 37 are sequentially laminated on the back surface of the support material 35.

Such a holder for an object to be polished is used by peeling off the release paper 37 and adhering it to the upper surface plate with an adhesive layer 36. At this time, the backing material 33 is impregnated with a liquid such as water,
The polished object is held in the backing material 33 by fitting the polished object into the recess hole 31a of the template 31 and strongly pressing the polished object against the packing material 33 via the liquid. In such a state, a polishing pad such as a cloth or a foam body capable of holding a polishing abrasive liquid is adhered to the lower surface plate, and a predetermined polishing pad is brought into contact with a surface of the object to be polished to be polished. Then, the object to be polished is slid relatively to the polishing pad by rotating the upper surface plate and the lower surface plate, respectively. Then, by flowing the polishing liquid, the polishing liquid is held by the polishing pad, and the surface of the object to be polished is polished.

[Problems to be solved by the invention]

The holder for holding the object to be polished is used by being attached to the upper surface plate. At this time, the object to be polished held by the object to be polished is rotated by the rotation of the upper surface plate, and the object to be polished is placed in the recess hole 31a of the template 31 so that the upper surface plate is Attempts to move in the direction of rotation. Therefore, the reset hole 31a in the template 31
, A portion of the peripheral portion of the object to be polished on the side of the rotational force acting direction, in particular, a corner portion of the rectangular recess hole and the vicinity thereof are strongly in contact with each other, and this portion tends to be selectively damaged. When the object to be polished has a square shape, the corner of the object to be polished is rotated with respect to the corner by rotation of the upper platen (for example, the fifth
The peripheral edge of the recess 31a (indicated by an oblique line A in FIG. 5) is particularly strongly contacted with the peripheral edge of the recess 31a facing in the direction indicated by the arrow B in FIG. Even if the damage of the template 31 is very small, between the recess hole 31a and the object to be polished,
When a gap is generated, the object to be polished can move freely in the recess hole 31a, and there is a problem that polishing accuracy is reduced. In addition, the workpiece and the recess
When the gap increases with the peripheral edge of the 31a, the impact force at the time of contact increases, and the damage is accelerated.

If the damage further progresses, the object to be polished rides on the remaining portion of the template 31 and jumps out of the recess hole 31a, causing an accident such as damage to the object to be polished or damage to the platen of the machine.

Such a problem is such that as the size of the object to be polished increases, the rotational force of the object to be polished and the impact load at which the object to be polished floating in the recess hole repeatedly collides increases. That is, as the size of the object to be polished increases, the length near the corner of the inner peripheral surface of the recess hole increases only one-dimensionally, whereas the rotational force and the impact load of the object to be polished are It is thought that it increases in proportion to the square of the length. Therefore,
When the area of the recess hole increases, the local impact pressure due to the rotation of the workpiece increases at an accelerated rate with respect to the increase in the inner peripheral surface of the recess hole that receives the rotational force and the impact load of the workpiece. The service life of the abrasive holder also decreases at an accelerated rate.

In order to address the above-mentioned conventional problems, it is conceivable to select a material for the template, but for that purpose, there are various difficulties.

Generally, the object to be polished is relatively thin,
In addition, if high precision is required for the finished thickness and flatness after polishing, the thickness of the template itself is also required to be high. For this reason, as a template, as a sheet-like material whose thickness can be controlled with high precision,
The material must be industrially available. That is,
When a high-strength, high-hardness material (for example, a thin metal plate) is used as a template to endure the local impact force received by the inner peripheral surface of the recess hole, when the object to be polished is a hard and brittle material such as glass, There is a disadvantage that the edge of the object to be polished is finely crushed, which causes a problem called chipping. In addition, when a resin sheet (for example, a glass epoxy plate or the like) filled with inorganic fibers such as glass fibers is used, the glass fibers and the like are broken and crushed by an impact force when the objects to be polished repeatedly collide, and the polished objects are crushed. Disadvantages such as damage to the edge of Fibrous-filled resinous sheets, such as woven-filled bakelite, have poor dimensional stability against heat of a heating press required during the bonding work when assembling and manufacturing the holder to be polished. There is a problem that abrasion due to abrasion occurs early from the corner portion of the template recess hole contacted by the force. In the case of engineering plastic sheets such as hard vinyl chloride, polysulfone, and polycarbonate,
When the abrasion resistance against repeated impact is excellent, but the dimensional stability against heat of the heating press required at the time of bonding work when assembling and holding the workpiece holder is poor, and the template is thin as described above. In the case where the mechanical strength to maintain the dimensions and shape of the template against the large rotational force generated by the large object to be polished by contact with the polishing pad is insufficient and the shape of the template itself has a narrow portion, The stress caused by the rotational force of the object to be polished concentrates on the narrow portion, so that the mechanical strength of the template material cannot withstand and starts to be destroyed with a small number of uses, furthermore, the rotational force continuously applied and the engineering plastic The template is deformed by the viscoelastic properties of the sheet, etc., and the object to be polished can move freely in the recess hole, and the polishing precision is increased. But there is a problem that decreases.

In general, if the object to be polished is relatively thin, and high precision is required for the finished thickness and flatness after polishing, the thickness of the template itself is equal to or less than the thickness. It is required to be thin and have high thickness accuracy. For this reason, the template must be a material that can be industrially obtained as a sheet-like material whose thickness can be controlled with high precision.

As described above, in these precision workpiece processing operations, even if a part of the template 31 is damaged or deformed, there is a possibility that the polishing accuracy of the workpiece is reduced or the workpiece is popped out. Therefore, it is necessary to frequently replace the entire workpiece holder. However, when replacing the workpiece holder, the work of polishing the workpiece must be interrupted.If the workpiece holder is frequently replaced, the work efficiency is significantly reduced, and the economic efficiency is reduced. There is a problem of spoiling.

This invention solves the above conventional problems,
The purpose is to be able to stably maintain the holding state of the object to be polished in the recess hole of the template for a long time,
A reduction in polishing accuracy can be suppressed, and the usable life of the holder to be polished can be extended and the frequency of replacement can be significantly reduced, so that the polishing operation efficiency can be significantly improved and the economy is excellent. The object to be polished is provided.

[Means for solving the problem]

In order to solve the above problems, the present invention takes the following technical measures.

The polished work holder of the present invention is mainly used for polishing the surface of the polished work such as a glass for flat display, a reflecting mirror, a crystal oscillator, and a semiconductor wafer. It comprises a template having a recessed hole for holding the object to be polished, and an insert removably held in the recessed hole, wherein the insert is detachably attached to the surface of the object to be polished. A backing material made of a polymer foamed elastic material, and a sheet material in which the template and the backing material are integrally adhered or adhered, and an inner peripheral surface of a recess hole of the template. At the corner on the backing material side, a stepped portion corresponding to the thickness of the backing material and having an appropriate width is provided, and the outer periphery of the backing material is fitted to this stepped portion. Characterized in that it is configured to have.

[Action]

The holder for the object to be polished of the present invention can obtain sufficient mechanical strength by increasing the thickness of the template, which is one of the problems of the engineering plastic sheet material. As a result, it is possible to prevent abrasion of the object to be polished and decrease in polishing accuracy due to the looseness of the object to be polished in the recessed hole, thereby preventing the holder of the object to be polished from being extended. It can be extended.

In addition, the template is used by increasing its thickness by a thickness corresponding to the thickness of the backing material, and at the corner on the backing material side on the inner peripheral surface in the recess hole, the template corresponds to the thickness of the backing material and has an appropriate width. It is assumed that the backing material is provided so that the outer periphery of the backing material is fitted to the stepped portion, so that the backing material is uniformly held with respect to the object to be polished, thereby lowering the polishing accuracy. Can be prevented.

〔Example〕

 The present invention will be described below with reference to embodiments.

The holder for an object to be polished of this embodiment is used, for example, when polishing an object to be polished having a rectangular shape in plan view. As shown in FIGS. 1 and 2, the holder for the object to be polished has a template 11 in which a rectangular recess hole 11a is opened in the center. The template 11 is made of a material having excellent toughness and abrasion resistance, is adhered to a backing material 14 via an adhesive layer or a pressure-sensitive adhesive layer 13 on the back surface, and an adhesive is provided on the back surface of the supporting material. Release paper 16 is adhered via the layer 15. A backing material 12 is bonded to the support material 14 through an adhesive layer or an adhesive layer 13 in the recess hole, and a release paper 16 is adhered to the back surface of the support material through an adhesive layer 15. I have.

The backing material 12 is made of a polymer that is microporously foamed so as to have fine voids inside.

The recess hole 11a in the template 11 has a stepped portion 19 having an appropriate width corresponding to the thickness of the backing material at a corner of the inner peripheral surface 18 of the recess hole on the backing material side.
The outer periphery of the backing material is fitted to this stepped portion.

Template 11 is made of engineering plastic with excellent toughness and abrasion resistance, and uses semi-rigid materials such as polycarbonate, hard polyurethane, hard vinyl chloride, etc., as well as higher hardness filled resin composite sheets. I can do it.

The number of the recess holes 11a formed in the template 11 is not limited to one, and may be plural. The recess hole 11a is generally square, for example, rectangular (eg, 350 mm × 250 mm)
It is determined according to the size of the object to be polished, such as a square shape (for example, 300 mm × 300 mm). Further, the shape may be a triangular shape, a polygon having five or more angles, a square shape such as a star shape, or the like.

The width of the stepped portion 19 in which the template and the backing material are fitted at the corner on the backing material side of the inner peripheral surface 18 of the template hole is usually smaller than the thickness of the template. 0.3 to 15
It is configured to be doubled. As shown in FIG. 4, the template and the backing material are bonded to the adhesive 17 at the stepped fitting portion.
May be bonded together. Further, the shape of the stepped fitting portion may be square as shown in FIG. 2 or arcuate as shown in FIG. 4, and there is a stepped portion on the template side and the backing material is It is important that the outer periphery is fitted to the stepped portion of the template further outward than the inner periphery of the recess hole. Further, as shown in FIG. 4, the corners of the outer peripheral edge of the template 11 may be chamfered over the entire circumference.

Further, an adhesive layer or an adhesive layer 13 shown in FIG.
14, a sheet material comprising an adhesive layer 15 and a release paper 16 is a double-sided adhesive tape in which a nonwoven fabric is impregnated with an adhesive, or a sheet material comprising an adhesive layer and an adhesive layer, as shown in FIGS. It may be.

The template 11 is made of a material having excellent toughness and abrasion resistance. For example, a fibrous filler and a high-toughness engineering plastic, a thermosetting resin, or a highly functional inorganic fiber such as carbon fiber or a Kepler. Press-forming, extruding, or forming into a sheet using a composite of high-abrasion-resistant fiber such as fiber and plastic, resin, or synthetic rubber, or a matrix substance alone or a filler filler. Are made by calendering or by further machining.

In order to achieve the object of the present invention, the material of the template 11 is selected from materials having appropriate physical properties in consideration of the material and surface dimensions and thickness of the object to be polished and the shape of the template. for use glass, comprising a hardness Rockwell M125 less, R60 or more, more compressive strength, preferably in the range of 400~2500kg / cm ^2, further wear resistance is resistance to so-called micro-vibration repeated impact wear Of particular importance. As for this resistance, a repetitive falling ball impact test was performed at a low energy level using a falling ball impact tester, and a material having a large cumulative impact energy until breaking was given a good result.

The backing material 12, by interposing a liquid such as water on the surface, when the object to be polished is strongly pressed,
Any material can be used as long as it can hold the object to be polished by suction. The backing material 12 is adhered to the support material 14 via the adhesive layer 13. However, the foaming composition may be provided directly on the support material 14 and integrated by a wet solidification method.

In the holder for the object to be polished in this embodiment, first, the backing material 12 is laminated on the support member 14 via the adhesive layer or the adhesive layer 13. Then, as shown in FIG. 2, a template 11 is adhered to such a laminate via an adhesive layer or an adhesive layer 13, and the template 11 and the backing material are connected to the inner peripheral surface of the recess hole 11a. At a corner of the backing material side 18, a stepped portion 19 having an appropriate width corresponding to the thickness of the backing material is provided, and the outer periphery of the backing material is fitted to this stepped portion.

 Next, a specific example of the embodiment of the present invention will be described.

Prepare a 1.0 mm thick polycarbonate template with a 300.1 mm x 300.1 mm hole in the center and a 0.5 mm deep and 5 mm wide square cutout on the periphery of the hole in the template. A backing material having a fine foam structure on the surface constituting the insert (Rodel Nitta Co., Ltd., trade name "DF-2
00 ") was cut into 304 mm x 304 mm. The cut backing material is bonded to a double-sided adhesive tape using a polyester sheet as a core material by using a heat roller, and then the template is formed on the double-sided adhesive tape at the stepped portion provided at the corner of the inner periphery of the recess hole of the template. FIGS. 1 and 2 show a holder for the object to be polished shown in FIGS. 1 and 2 which was bonded using a heat roller so that the outer periphery of the backing material was fitted.

Square glass (0.8 m thick) for liquid crystal display is inserted into the recessed hole of the template in the obtained holder.
m, size 300.0 × 300.0 mm), and the square glass was polished with a cerium oxide-mixed abrasive. The polishing rate at this time is 0.6 μm / min, and the temperature of the polishing cloth is 53 ° C.
Met. Under these conditions, square glass, which is the object to be polished, was sequentially fitted into the recess hole and polished.
Each square glass could be polished without reducing the finishing accuracy (plane accuracy). At this time, the periphery of the recess hole was worn by about 0.2 mm, so the polishing operation was stopped and the holder for the object to be polished was replaced. The finished planar accuracy of the polished square glass was within 0.2 μm per 25 mm × 25 mm.

Another specific example of the present invention will be described. Prepare a template made of polysulfone resin with a thickness of 1.5 mm and an arc-shaped notch with a depth of 0.6 mm and a width of 10 mm at the periphery of a template hole with a rectangular recess hole of 350.1 mm × 250.1 mm at the center. Then, it was adhered in the same manner as in the previous example to produce a holder for the object to be polished. A rectangular glass (thickness: 1.1 mm × 350.0 mm × 250.0 mm) for a liquid crystal display is fitted into the recessed hole of the template in the obtained holder for the object to be polished, and the rectangular glass is mixed with a cerium oxide mixed abrasive liquid. Polished. The polishing rate at this time was 0.7 μm / min, and the temperature of the polishing pad was 55 ° C. Under these conditions, the square glass to be polished was sequentially fitted into the recess hole and polished.
Was able to be polished without lowering. The finished flatness of polished square glass is 25mm x 25mm,
It was within 0.2 μm, which was high precision.

The holder for the object to be polished of this embodiment can use an industrially easily available engineering plastic sheet material having excellent toughness and abrasion resistance as a material of the template. This can solve the problem that the wear due to abrasion occurs early from the corner of the template recess hole that comes into contact with the impact force at the time of repeated collision. That is, the holder for the object to be polished of this embodiment is made of a template material having excellent toughness and abrasion resistance, and has the ability to receive the abrasion action caused by contact with the object to be polished. There is no risk of adversely affecting chipping and the like.

As a result, the life of the workpiece holder can be prolonged, and the play-fit state of the workpiece in the recess hole can be suppressed as much as possible during the life of the workpiece holder. However, high productivity can be achieved.

Thereby, the processing accuracy can be stabilized, and the quality of the object to be polished can be stably improved.
The productivity and economy of the polishing operation can be significantly improved.

[Effect of the invention]

The holder for the object to be polished of the present invention has the ability to receive the stress caused by contact with the object to be polished because the template is thicker by an amount corresponding to the thickness of the backing material. It is possible to greatly extend the life of the holder for the object to be polished.

In addition, at the corner of the inner peripheral surface of the recess hole of the template on the backing material side, there is a stepped portion on the template side, and the outer periphery of the backing material fits further outward from the inner periphery of the recess hole to the stepped portion of the template. As a result, the backing material is uniformly held with respect to the object to be polished, so that a reduction in polishing accuracy can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of the holder for a polished work of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing still another example of the polished work holder of the present invention, FIG. 5 is a plan view of a conventional polished work holder, and FIG. It is sectional drawing in IX-IX of a figure. 11 ... template, 11a ... recess hole, 12 ... backing material, 14 ... support material, 18 ... inner peripheral surface of template recess, 19 ... stepped fitting part.

Claims (1)

(57) [Scope of request for utility model registration] An object holder mainly used for polishing the surface of an object to be polished such as a glass for flat display, a reflector, a crystal oscillator, a semiconductor wafer, etc., wherein the object to be polished is A template having a recess hole to be fitted therein; a backing material made of a polymer foamed elastic body which can be detachably attached to the surface of the object to be polished in the recess hole; A sheet material integrally adhered or adhered to a backing material, wherein the template has a thickness increased by a thickness corresponding to the thickness of the backing material, and a backing material on an inner peripheral surface of the recess hole. A stepped portion corresponding to the thickness of the backing material and having an appropriate width is provided at the side corner, and the outer periphery of the backing material is fitted to this stepped portion. A holder for an object to be polished, characterized in that it is configured as follows.