JP3075614U - Polishing work carrier - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure the required rigidity of a work carrier and to improve the durability life and polishing accuracy by increasing the wear resistance of the surface layer. SOLUTION: Adhesive layers 20a, 2 are provided on both upper and lower surfaces of a core material 11.
0b, the core material 11 is a plastic or stainless steel reinforced with an inorganic material such as an epoxy resin impregnated glass cloth, and the surface materials 12a and 12b are made of ultra-high molecular weight polyethylene. That.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a polishing work carrier. More specifically, when polishing a work (material to be polished) such as a semiconductor wafer, a hard disk, and a liquid crystal display glass, the work is held between the upper and lower platens of a lapping apparatus. Related to work carriers arranged in the form.

[0002]

[Prior art]

 In general, a lapping apparatus for a semiconductor wafer or the like arranges a work carrier 100 (hereinafter simply referred to as a carrier) so as to constitute a planetary gear mechanism 3 between an upper surface plate 1 and a lower surface plate 2 as shown in FIG. are doing. In each carrier 100, a work W such as a wafer is accommodated and held in a work hole 101, and the carrier 100 is rotated while supplying the polishing liquid 4 so that a work is performed by an upper platen 1 and a lower platen 2. Polish both sides of W.

Since the work W is generally relatively thin, such as 0.5 to 1.2 mm, the carrier 100 must also be made appropriately thin. However, since the carrier 100 is provided with a gear portion 102 on the outer periphery, rigidity is reduced. is necessary. Therefore, conventionally, an epoxy resin impregnated glass cloth is used as the material of the carrier 100, and a carrier having a three-layer structure is also known. In such a case, an inorganic filler is used in the core material (intermediate layer) in the PET resin. The filled material is used, and the surface material is an epoxy resin impregnated glass cloth.

[0004]

[Problems to be solved by the invention]

 However, in the conventional carriers described above, since the surface layer is made of glass cloth impregnated with epoxy resin, there is a problem that the surface of the carrier is easily worn by the abrasive and the usable life is short, and the glass released by the abrasion is also used. The powder adheres to a relatively soft work, and the work is easily scratched unnecessarily, and there is a problem in polishing accuracy.

[0005] In view of the above-mentioned conventional circumstances, the present invention solves the problems and problems, secures the rigidity required for the carrier, and increases the abrasion resistance of the surface layer to improve the durability life and polishing accuracy. The goal is to improve.

[0006]

[Means for Solving the Problems]

 The present invention relates to a polishing work carrier in which a surface material is adhered to upper and lower surfaces of a core material via adhesive layers, wherein the core material is a plastic reinforced with an inorganic substance, and the surface material is an ultra-high molecular weight polyethylene. It is characterized by the following (claim 1). According to the present invention, the rigidity required for the carrier is secured by the plastic reinforced with the inorganic material as the core material, and the abrasion resistance is secured by the ultra-high molecular weight polyethylene as the surface material.

The plastic reinforced with the inorganic material is not particularly limited in the inorganic material, but it is preferable to use, for example, an epoxy resin impregnated glass cloth from the viewpoint of securing the rigidity of the carrier (Claim 2). If a stainless steel material is used as the core material instead of the plastic reinforced with the inorganic material (claim 3), the adverse effects of the inorganic material such as glass released during polishing can be eliminated.

[0008] The ultra-high molecular weight polyethylene used as the surface material has a structure in which very long molecular chains are intertwined in a complicated manner, so that it has excellent abrasion resistance and impact resistance, and is composed of only carbon and hydrogen. Since the composition only contains about 100 ppm of catalyst residue and about 1000 ppm of stearate, it does not adversely affect the work. On the other hand, ultra-high molecular weight polyethylene is chemically stable and therefore difficult to adhere to.However, modified polyolefin obtained by copolymerizing polyolefin and unsaturated carboxylic acid, or polyolefin and unsaturated carboxylic acid derivative are copolymerized. If a modified polyolefin or a mixture of the two modified polyolefins, an epoxy-based adhesive, a rubber-based adhesive, and an α-cyanoacrylate-based adhesive are used, they can be bonded to the surface layer material with sufficient strength as a carrier. The above-mentioned adhesive can also be bonded to a core material made of an epoxy resin impregnated glass cloth or stainless steel, but an adhesive suitable for bonding to the core material and an adhesive suitable for bonding to the surface material are selected. An adhesive layer having a multilayer structure using different adhesives is optional (claim 4).

Further, in a carrier in which a surface material is adhered to both upper and lower surfaces of a core material, the surface material may be slightly distorted or warped due to a difference in expansion coefficient between the core material and the surface material. Considering this point, it is preferable to form a large number of through holes vertically penetrating the core material and fill the through holes with ultra-high molecular weight polyethylene as a surface material (claim 5). According to this, both the upper and lower surface materials can be integrated via the ultra-high molecular weight polyethylene in the through-hole, thereby reducing the difference in expansion coefficient between the core material and the surface material to reduce distortion and warpage. The occurrence can be prevented. It is preferable that the through hole is not opened in a portion where a gear portion is formed in order to avoid a decrease in strength (rigidity). The size and number of the through holes depend on the size of the core material, but are generally about 3 to 6 mm in diameter (claim 6).

[0010]

[Embodiment of the invention]

 FIG. 2 shows a partially cutaway front view of a carrier 10 used in a lapping device and a partially enlarged view of the embodiment. The carrier 10 has a disk shape in a plan view, and has a plurality of work holes 13 penetrating vertically, and the work W is fitted and accommodated in each hole 13 and has a gear portion 14 on the outer peripheral edge. This is the same as the above-described conventional carrier 100.

As shown in FIG. 2 (2), the carrier 10 has surface materials 12a, 12b adhered to upper and lower surfaces of a core material 11, which is a central layer, via adhesive layers 20a, 20b, respectively. It's a trivial thing. The core material 11 is an epoxy resin impregnated glass cloth exemplified as a plastic reinforced with an inorganic substance, and the surface materials 12a and 12b are sheets of ultrahigh molecular weight polyethylene.

Next, FIG. 3 is a partially enlarged view of a carrier 30 showing another embodiment. Although not shown, a work hole and a gear portion are the same as in the case of the carrier 10. The carrier 30 has a core material 31 made of a stainless steel disk, and surface materials 32a and 32b made of a sheet of ultra-high molecular weight polyethylene adhered to upper and lower surfaces thereof via adhesive layers 40a and 40b, respectively. is there.

The core material 31 is provided with a number of through holes 33 formed of small holes penetrating up and down in portions other than the work hole and the gear portion, and each through hole 33 has an ultra-high height of the same material as the surface material. Molecular weight Polyethylene 32c is filled. That is, before forming the adhesive layers 40a and 40b and the surface materials 32a and 32b, a through hole 33 is formed in the core material 31 and an ultra-high-powder material is injected into the through hole by a powder or fine pulverization method. After filling with molecular weight polyethylene 32c, adhesive layers 40a and 40b are applied, and surface materials 32a and 32b are adhered. The through-hole 33 is a small hole having a diameter of about 3 to 6 mm, and is appropriately arranged with a regular or irregular pitch.

[0014]

【Example】

 FIGS. 4 and 5 show examples of the carriers 10 and 30 corresponding to FIGS. 2 (2) and 3 respectively. Example 1 FIG. 4 shows Example 1 showing a part of a carrier 10 made of a disk having a diameter of about 600 mm. A core material 11 is an epoxy resin impregnated glass cloth, and surface materials 12a and 12b are ultra-high molecular weight polyethylene. It is. The adhesive layers 20a and 20b each have a two-layer structure, in which the adhesive 21 is a modified polyolefin obtained by copolymerizing a polyolefin and a derivative of an unsaturated carboxylic acid (maleic anhydride), and the adhesive 22 is a polyolefin. It is a modified polyolefin copolymerized with an unsaturated carboxylic acid (methacrylic acid). The thickness relationship of each layer is as shown in the figure (unit: mm), and the surface layer materials 12a and 12b and the core material 11 are about 1: 4. According to the carrier 10 of Example 1, it was confirmed that the abrasion resistance was improved 2.5 times as compared with the conventional carrier of the epoxy resin impregnated glass cloth alone. Although a warp of 0.15 mm was generated, such a degree does not particularly hinder practical use.

Second Embodiment FIG. 5 shows a second embodiment showing a part of a carrier 30 composed of a disk of the same size as the carrier 10 of the first embodiment, wherein a core material 31 is a stainless steel plate and a surface material 12a. , 12b are ultra high molecular weight polyethylenes. The adhesive layers 40a and 40b have a two-layer structure in which the adhesive 41 is an epoxy-based adhesive and the adhesive 42 is an ethylene-propylene-terpolymer (EPDM), and the core material 31, the surface materials 12a and 12b, etc. The thickness relationship of each layer is the same as in Example 1 (unit: mm) as shown in the figure. In the case of this carrier 30 as well, it was confirmed that the abrasion resistance was improved by a factor of 2.5 as compared with the conventional carrier made of a single piece of glass cloth impregnated with epoxy resin, and no warpage occurred unlike in Example 1.

In the above embodiments and examples, the case where the through hole 33 is formed in the carrier 30 made of stainless steel as a core material and the through hole is filled with ultra-high molecular weight polyethylene has been described. The same configuration may be adopted in the case of the carrier 10 using glass cloth as a core material, and even in the case of the carrier 30, it is optional that the through holes 33 filled with ultra-high molecular weight polyethylene are not included. is there. Further, in the above embodiment, a two-layer adhesive layer using two types of adhesives on each of the upper and lower surfaces has been exemplified. However, a three-layer or more multilayer structure, or a single-layer adhesive layer on each surface may be used. Good.

[0017]

[Effect of the invention]

 According to the present invention, the core material is made of plastic or stainless steel reinforced with an inorganic material such as an epoxy resin impregnated glass cloth, so that the required rigidity as a carrier is secured. Wear and impact resistance are ensured. Therefore, the surface structure of the carrier, which is hard to be worn, can be used to extend the durable life, and the inorganic substance such as glass powder is not exposed to the surface layer, so that the inorganic substance may be released during the polishing operation. Polishing accuracy can be increased without damaging the work such as a semiconductor wafer (claims 1 to 3).

According to the fourth aspect of the present invention, the surface layer material can be firmly and integrally adhered to the core material, and a more rigid carrier can be provided. Further, according to claims 5 and 6, the upper and lower surface materials are integrally connected to each other, so that the difference in expansion coefficient between the core material and the surface material is reduced, so that there is no carrier structure in which distortion and warpage do not occur. obtain.

[Brief description of the drawings]

FIG. 1 exemplifies a general lapping apparatus, in which (1) is a plan view omitting a surface plate, and (2) is a front view thereof.

FIG. 2 shows the work carrier of the present invention, (1)
Is a partially cutaway front view, and (2) is a partially enlarged view.

FIG. 3 is a partially enlarged view of a work carrier according to another embodiment.

FIG. 4 is a partially enlarged view showing a work carrier according to the first embodiment.

FIG. 5 is a partially enlarged view showing a work carrier according to a second embodiment.

[Explanation of symbols]

10: Work carrier 11: Core material 12
a, 12b: Surface material 13: Work hole 14: Gear part 20
a, 20b: adhesive layer 30: work carrier 31: core material 32
a, 32b: Surface layer material 33: Through hole 32c: Ultra high molecular weight polyethylene 40a, 40b: Adhesive layer

Claims (6)

[Utility model registration claims] 1. A polishing work carrier in which a surface material is adhered to upper and lower surfaces of a core material via adhesive layers, wherein the core material is a plastic reinforced with an inorganic substance, and the surface material is ultra-high molecular weight polyethylene. A polishing work carrier characterized by the following: 2. The plastic reinforced with an inorganic substance,
A work carrier for polishing characterized by being an epoxy resin impregnated glass cloth. 3. The polishing work carrier according to claim 1, wherein said core material is stainless steel. 4. The method according to claim 1, wherein the adhesive layer has a multilayer structure using different adhesives.
The work carrier for polishing according to the above item. 5. The core material according to claim 1, wherein a number of through holes vertically penetrating the core material are formed, and the through holes are filled with ultra high molecular weight polyethylene as a surface material. The work carrier for polishing according to the above item. 6. The polishing work carrier according to claim 5, wherein the through holes have a diameter of 3 mm to 6 mm.