JPS5944185B2 - Fixing device for ceramic surface plate for polishing - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fixing device for fixing a ceramic surface plate used in a polysinking process of semiconductor wafers to a surface plate holder, and more specifically, a fixing device for fitting a retaining ring to a ceramic surface plate for polysinking. The present invention relates to a device for fixing the ceramic surface plate for polysink (hereinafter simply referred to as ceramic surface plate) by fixing this presser ring to the surface plate holder.

In polysinking semiconductor wafers, the polished wafer is required to have highly accurate flatness, so a polishing surface plate that can maintain this highly accurate flatness is required. That is, this type of surface plate must satisfy three conditions: first, it should not be corroded by chemical polishing liquid, second, it should be hard, and third, it should be resistant to thermal deformation. For this reason, ceramic surface plates have recently been used instead of the conventional stainless steel to better satisfy these three conditions.
Conventionally, the device usually used to fix a ceramic surface plate to a surface plate holder is to form several recesses 2 (only one is shown) on the bottom surface of a ceramic surface plate 1, as shown in Fig. 1. In this device, tapped metal blocks 3 are respectively embedded in the recesses 2 and bonded together, and the metal blocks 3 are fixed to the surface plate support 4 with bolts 5. However, with this device, the ceramic surface plate 1 is easily chipped or cracked at the joint surface with the metal block 3, and it is difficult to maintain the adhesive state between the ceramic surface plate 1 and the metal block 3. However, there is a drawback that the metal block 1 often peels off. Also, since the size of the ceramic surface plate 1 changes when it is fired, the concave portion 2
It is difficult to achieve dimensional accuracy of metal block 3.
There is a drawback in that it is difficult to tightly embed and bond the material into the recess 2. Furthermore, ceramic surface plate 1
Since the bottom surface of the ceramic surface plate 1 is fixed to the surface plate holder 4 at only a few places, there is a drawback that reliable fixation cannot be expected, especially when the ceramic surface plate 1 is large. An object of the present invention is to provide a fixing device for a ceramic surface plate that eliminates such drawbacks, and its features include a ceramic surface plate having an engaging portion formed on its circumferential surface, and a device that fits into the ceramic surface plate. An elastic ring is attached to the ceramic surface plate, and an inner circumferential surface is formed to follow the circumferential surface of the ceramic surface plate. It consists of a presser ring and a presser ring that is fixed in place. below,
A preferred embodiment of the present invention will be described in detail with reference to FIGS. 2 and 3 of the accompanying drawings.

Reference numeral 10 denotes a ceramic surface plate, which is chamfered over its entire circumference from the top surface to approximately the center in the thickness direction, and a tapered engagement portion 11 is formed.

A rubber ring 12, which is an elastic ring, is fitted onto the circumferential surface of the ceramic plate 10, and the inner circumferential surface is aligned with the circumferential surface of the ceramic surface plate 10 through the rubber ring 12, so that the inner circumferential surface is aligned approximately at the center in the thickness direction. A presser ring 13 is fitted with a presser ring 13 that is formed so as to taper in diameter toward the upper surface. The upper surface of the presser ring 13 is connected to the ceramic ivy surface plate 1.
It is located slightly below the top surface of 0. The presser ring 13 is fixed to the surface plate support 14 at several locations with bolts 15 serving as fixing members. In this embodiment, since the engaging portion 11 is formed into a tapered shape, there is an advantage that centering is easy when fixing the ceramic surface plate 10 to the surface plate support 14.

It should be noted that the engaging portion 11 does not always need to be formed in a tapered shape, and may have any shape, such as a stepped shape, as long as it can prevent the ceramic surface plate 10 from coming off the presser ring 13. In this way, according to the present invention, the following effects can be achieved.

First, there is no need to form a recess for embedding and bonding the metal block in the ceramic surface plate as in the past.
Its manufacture becomes extremely easy. Second, since the ceramic surface plate is held down on its entire circumference by the retaining ring fixed to the surface plate holder, it is possible to protect the periphery of the ceramic surface plate and securely fix it to the surface plate holder. Also,
There is no deformation of the ceramic surface plate due to partial tightening as in the conventional case. Thirdly, since the presser ring is fitted to the ceramic surface plate through the elastic ring, even if there is a slight error between the circumferential surface of the ceramic surface plate and the inner circumferential surface of the presser ring, it is absorbed by the elastic ring. In particular, it is possible to securely fix the ceramic surface plate without requiring high dimensional accuracy in manufacturing it. Although the present invention has been explained in detail by citing preferred embodiments above, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and many modifications can be made without departing from the spirit of the invention. Of course it can be difficult.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the main part showing the fixed state in a conventional example, FIG. 2 is a longitudinal cross-sectional view of the main part showing the fixed state in an embodiment of the present invention, and FIG. 3 is a general plan view of the same state. It is a diagram. 1... Ceramic surface plate, 2... Concavity,
3... Metal block, 4... Surface plate support, 5... Bolt, 10... Ceramic surface plate, 11... Engagement Part, 12... Rubber ring, 13... Presser ring, 14...
・Surface plate support, 15... bolts.

Claims (1)

[Claims] 1. A ceramic surface plate for polysink having an engaging portion formed on its peripheral surface, an elastic ring fitted to this ceramic surface plate for polysink, and an inner peripheral surface formed to follow the peripheral surface of the ceramic surface plate for polysink. and a presser ring that is fitted to the ceramic surface plate for polysink via the elastic ring and fixed to the surface plate holder by an appropriate fixing member. fixation device.