JP2003170351A - Tool plate of polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool plate of a polishing device which plate can lengthen useful life and smoothen dispersion of carrier particulates. <P>SOLUTION: At least a working surface of a disc type tool main body 1 made of fine ceramics of at least 95% purity is formed irregular with roundness having surface roughness Ra of 4-20 μm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool plate of a polishing device which is attached to a polishing surface plate of a polishing device and polishes (polishing, lapping) a workpiece.

[0002]

2. Description of the Related Art A tool plate of a polishing apparatus holds innumerable carrier (medium) fine particles holding abrasive grains instead of a polishing cloth (polishing pad) for polishing a workpiece, and has conventionally been about Ra 4 μm. Those made of frosted glass having a surface roughness are known (see 2000 Proceedings of Academic Conference of the Japan Society for Abrasive Grain Processing, pages 47 to 48).

[0003]

However, since the tool plate of the conventional polishing apparatus is made of glass, it has a problem that it is easily worn and its service life is short. Further, since the unevenness of the work surface is physically (mechanically) formed by sandblasting using silica sand or the like, the concave portion is expanded outward (having a V-shaped cross section), while the convex portion is convex. The part has a pointed shape that faces outward, and there is a problem that the carrier fine particles cannot be diffused smoothly.

Therefore, an object of the present invention is to provide a tool plate of a polishing apparatus which can prolong the service life and can smoothly diffuse carrier fine particles.

[0005]

In order to solve the above problems, the tool plate of the polishing apparatus of the present invention is such that at least the working surface of a disk-shaped tool body made of dense ceramics having a purity of 95% or more has a surface roughness. It is characterized in that it is formed in a rounded unevenness of Ra 4 to 20 μm.

The dense ceramic has a theoretical density of 9
A density of more than 0% is preferred.

The dense ceramics are preferably alumina, yttrium aluminum garnet, yttria, aluminum nitride, silicon nitride or zirconia.

[0008]

In the tool plate of the polishing apparatus of the present invention,
The hardness is higher than that of glass, and the movement of the carrier fine particles between the concave portions is facilitated, while the anchor effect (anchoring effect) on the back surface at the time of adhesion using an adhesive is enhanced.

If the density of the dense ceramics is less than 95%, the workpiece may be contaminated, and
This causes the properties of the work to be remarkably deteriorated. The purity of the dense ceramics is more preferably 99% or more. If the surface roughness Ra of the irregularities is less than 4 μm, the holding power of innumerable carrier fine particles is weakened or flows. on the other hand,
If it exceeds 20 μm, the polishing efficiency becomes extremely low. The surface roughness Ra of the unevenness depends on the diameter of the carrier fine particles,
10 to 20 μm is more preferable.

If the density of the dense ceramics is 90% or less of the theoretical density, the product will be deteriorated due to impurity contamination of the workpiece. The density of dense ceramics is 9 which is the theoretical density.
9% or more is more preferable.

As the dense ceramics, the above-mentioned various types can be cited. One of the particularly effective ones is alumina ceramics. Among the alumina ceramics, those of high purity and large particle size are desirable. It is also preferable to be precise. This is because if the amount of impurities is large, it becomes difficult to perform ideal etching, and the purity is preferably 99% or more, more preferably 99.5% or more. Especially preferably, it is 99.9% or more. or,
The average particle size is preferably as large as possible within the range of 5 to 50 μm. If the particle size is larger than 50 μm, the strength of the ceramic itself tends to be inferior. On the other hand, if the particle size is too small, it becomes difficult to obtain the effects of the present invention. The average particle diameter is more preferably 10 to 50 μm, particularly preferably 10 to 45 μm. As a representative of such alumina ceramics, for example, one having translucency is suitable for the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual sectional view showing an example of an embodiment of a tool plate of a polishing apparatus according to the present invention. The tool plate of this polisher has a purity of 95
% Or more (preferably 99% or more), 90% of the logical density
Working surface (top surface in FIG. 1) and back surface (FIG. 1) of the disk-shaped tool body 1 made of dense ceramics having a density exceeding
Both sides of the lower surface in FIG.
a, 3a and convex portions 2b, 3b, surface roughness Ra4 to 2
It is formed on the unevenness 2 and 3 of 0 μm. Dense ceramics include alumina, yttrium aluminum garnet, yttria, aluminum nitride,
Silicon nitride or zirconia is used.

The tool plate of the polishing apparatus described above is made of dense ceramics having a purity of 95% or more and a density exceeding 90% of the logical density, and the disk-shaped tool body 1 having a smooth surface is heated at 100 to 230 ° C. 18 to 5 concentration maintained at the temperature
The tool body 1 is dipped in a 0% sulfuric acid aqueous solution or a 95% or more concentrated phosphoric acid aqueous solution (etching solution) for 10 to 16 hours.
Is gradually chemical-etched so as to form rounded irregularities 2 and 3 having a surface roughness Ra of 4 to 20 μm.

Here, the purity is 99.7% and the bulk density is 3.97.
g / cm ^2, made from the average grain size 40μm of alumina ceramics, a smooth surface disc shape (diameter 1000 mm, thickness 10 to 30 mm) tool body 1, 230 ° C. 25% strength aqueous sulfuric acid maintained at a temperature of Then, the tool plate was obtained by presenting rounded irregularities 2 and 3 with a surface roughness Ra of 4 μm on both the working surface and the back surface for 16 hours. The obtained tool plate is adhered to the upper surface of the polishing surface plate of the polishing apparatus with an adhesive (epoxy resin) interposed between the tool plate and the back surface of the tool plate, and an aqueous solution of colloidal silica having an average particle diameter of 10 to 20 nm (concentration: 5 wt %, PH 10.3), a mixed solution of 1 wt% of polymer fine particles having an average particle diameter of 2 μm and 3 wt% of polymer fine particles having an average particle diameter of 15 μm was used as a polishing liquid to polish a silicon wafer.
Compared with the case of polishing a silicon wafer under the same conditions by using frosted glass with a surface roughness of 4 μm as a tool plate, the service life can be increased by 2 to 3 times and carrier fine particles can be smoothly diffused to the work surface. It was conducted. or,
The tool plate could be easily bonded to the polishing platen, and the bonding strength was 1.2 to 2.0 times higher.

In the above-described embodiment, the case where the tool body 1 has the concavities and convexities 2 and 3 formed on both sides has been described, but the present invention is not limited to this and only one side serving as a work surface is described. The unevenness 2 may be formed.

[0016]

As described above, according to the tool plate of the polishing apparatus of the present invention, the hardness is higher than that of glass, and the carrier fine particles can be easily moved between the concave portions, so that the useful life is greatly extended. The length can be made very long and the diffusion of carrier fine particles can be made smooth. On the other hand, when unevenness is also formed on the back surface, the anchor effect on the back surface at the time of bonding with an adhesive is increased, so that the tool plate can be easily bonded to the polishing platen and the bonding strength is remarkably high. Can be increased.

[Brief description of drawings]

FIG. 1 is a conceptual sectional view showing an example of an embodiment of a tool plate of a polishing apparatus according to the present invention.

[Explanation of symbols]

1 Tool body 2 unevenness 2a recess 2b convex part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumio Tokutake             30 Soya, Taino City, Kanagawa Prefecture Toshiba Cerami             Kusu Co., Ltd. Development Laboratory (72) Inventor Hideo Uemoto             30 Soya, Taino City, Kanagawa Prefecture Toshiba Cerami             Kusu Co., Ltd. Development Laboratory F-term (reference) 3C058 AA07 AA09 CB05 DA02                 4G030 AA12 AA17 AA36 AA51 AA52                       BA18 CA07 GA32

Claims (3)

[Claims] 1. A polishing apparatus characterized in that at least a working surface of a disk-shaped tool body made of dense ceramics having a purity of 95% or more is formed into rounded irregularities having a surface roughness Ra of 4 to 20 μm. Tool plate. 2. The dense ceramics has a theoretical density of 9
The tool plate of a polishing apparatus according to claim 1, wherein the tool plate has a density of more than 0%. 3. The tool plate of the polishing apparatus according to claim 1, wherein the dense ceramic is alumina, yttrium aluminum garnet, yttria, aluminum nitride, silicon nitride or zirconia.