JPS58149168A - Grinding method - Google Patents

Abstract

PURPOSE:To simultaneously grind both sides of a work, by interposing a sheet- shaped holder having work holding holes between upper and bottom rotary grinding surface plates and supporting said holder with a holder supporting bed. CONSTITUTION:A holder 22 is interposed between upper and bottom grinding surface plates 20, 21, and its external edge part or external and internal edge parts are fixed to holder supporters 25 by tightening tools 25. A work 23 is held to work holding holes 24 of the holder. The upper and bottom grinding surface plates and the holder supporter can be independently rotated respectively on the same rotary shaft. While a holder supporting bed is capable of adjusting upper and bottom positions to always horizontally hold the holder. In this way, both sides of a very into work can be simultaneously ground.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a new and improved polishing method, which is particularly advantageous for simultaneously polishing both surfaces of a workpiece having a thickness of 300 μm or less. Research! This relates to the structure of the equipment.

Usually, in order to polish both sides of a wafer made of single crystal such as quartz, LiTaO3, GGG, ceramic lag, or gold, there is a method of polishing two types of C on each side of the wafer, or a method of polishing both sides of the wafer. One of the methods of simultaneously polishing is adopted.

Conventionally, to polish the sea urchin one side at a time.

For example, as shown in Figure M1: I:, one or more wafers to be polished are firmly placed on the lower surface of the same-shaped holder 2, the wafer is brought into contact with the polishing surface of the polishing foot gI3, and the contact boundary is Supply polishing liquid to the surface 1. t, the above holder and the grinding Ml! All the foot plates must be rotated and polished, or 1!
2 Figure I: As shown I: Fixed instep foot 4 through suitable HV-) shaped papudo 5! - Holes 6 for holding multiple wafers?
Does it have a retaining plate? f? 1 stare at the wafer 11 in the 60
Polishing 11 of the wafer and polishing process 118 in the stored state!
1' There is a known method of polishing in the presence of a polishing solution.

-If you want to polish both sides of the wafer at the same time,
Figure I: As shown, the doughnut-shaped top and bottom polishing IIM9.
10 g=1 to a plurality of carriers 111-f, and each of these carriers is engaged between the additional gear 12 and the internal gear 13 so that 11 star movements can be performed, and the carrier I: Each of the holes 14 accommodates all of the sea urchins 8-1 to be polished.
, 10. A method is known in which both sides of the 529 Ever are polished in the same manner in the presence of a polishing liquid while rotating the chin gear 12 and the internal gear 13 at the same time.

However, when polishing both sides of the square using the conventionally known polishing process twice for each side, there are two problems.

The polishing process is complicated, the main verticality is poor, and during the complicated polishing process, there are scratches on the polished surface, especially when bonding and fixing the polished surface to the lower rM of the holder after polishing one side. Because of the contact, the basic FJ42 requires precision polishing on both sides ≦
: has disadvantages and drawbacks such as being unsuitable, -10, In the case of double-sided simultaneous polishing accompanied by uneven movement of the play housing, the carrier is engaged with both the number gear and the internal gear to make the 'aM movement. Because of this, there is an RI limit to the thinning of this carrier, and therefore the thickness of a wafer that can be polished on both sides with this method is at most 3 (10μWL), and workpieces with a thickness smaller than that can be polished. The problem was that it was impossible.

The present invention provides a new and improved polishing method capable of simultaneously polishing both sides of an ultra-thin wafer having a thickness of 300 wL or less, and is provided with a rotating upper and lower polishing surface plate. In between, there are holes for holding the workpiece.
A plurality of thin plate-like holders are interposed, and the outer radius of the holder is
A preferred embodiment of the present invention is characterized in that both sides of a workpiece held in and held in a hole of the holder are simultaneously polished by being fixedly supported on a holder support base. At 52, the upper and lower polishing plates and the holder are each rotated.

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

Figures 4 and 5 respectively show different embodiments of the apparatus for carrying out the present invention, and Embodiment #1 shown in Figure 4C2. It consists of a top and bottom polisher 920° 21 and a thin plate-like holder 22 placed between these surface plates. Multiple holes 24 for housing and holding? In the evening, the outer peripheral edge of the shell is fixedly held on the holder support base 25, and the upper and lower surfaces are polished l112.
0.21 and the holder support base 25 are each rotatable independently on the same rotation axis. Note that the tightening jig used for fixing the #1 holder 22 to the holder support base (26 in Figure 1) is normally tightened using a large number of bolts.

11. The embodiment shown in the Yusho S figure is a donut-shaped top and bottom polishing process! Il! 20.21, and a donut-shaped thin plate holder 22 placed between these surface plates. , these holder support stands are connected at their j&to, and the upper and lower polishing surface plates 20, 21 and the holder support stand 25 are configured to be able to rotate independently on the same rotating glaze.

In the polishing apparatus used in the present invention, the above-mentioned 411i2V
The holder 22 is fixed to the holder support base 25 at its peripheral edge by the tightening jig 26, so there is no damage.

At this time, it is preferable for the holder 22 to be as close to horizontal as possible, and at this time, it is desirable to apply an appropriate tension to the holder C2, so that the workpiece can be held in a good manner 111', and the polishing precision can be improved. Improvement can be achieved. In addition, it is desirable that the lower surface plate 21 and the holder support stand 25 have a structure in which the upper and lower sides can be adjusted, and that the upper and lower positions can be adjusted so that the holder is kept horizontal throughout the entire surface during polishing work. Furthermore, the upper and lower legs a can be moved in the same direction or in the opposite direction 10,000 times!
It is recommended to use L5g, which allows you to select and adopt any rotation method depending on the rotation method required when polishing. is rotatable in any direction i2, and is rotated in the preferred direction during polishing, thereby rotating the workpiece l together with the holder.
: It is desirable to give orbital motion. Of course,
It is possible to have both the upper and lower polishing surface plates and the holder support stand in a stopped state, and their rotation speed is also variable, and the upper and lower polishing surface plates and the holder support stand are stopped individually.

By selecting conditions such as the direction of one rotation and the rotation speed, the mutual interlocking of the wafer to be polished and the upper and lower surface plates during polishing can be widely selected.

However, 1) the features of the present invention and 2) are as follows.

@Figure 4 section = As shown, the outer circumferential edge of the thin plate-like holder 22 is fixedly held on the holder support base 251, or as shown in FIG. There is a mini part that polishes the wafer by holding it fixedly, and this C2 determines the thickness of the holder 22.
Conventionally known planetary motion? Compared to the thickness of the carrier in the accompanying grinder *5iitt=, it can be made much thinner because it is much η, and for example, if this holder 22 is made of a material such as stainless steel, 1! Since kl: can be made to have a density of 300 μm or less, as a result, 300μI, which was previously considered to be unusable, can be
Simultaneous polishing of both sides of a wafer with a thickness of II or less cannot easily be achieved.

As mentioned above, the method of invention
The workpiece is held in a plate-shaped holder, sandwiched between the upper and lower polishing plates from above, and the workpiece and the polishing plates are moved relative fFJ≦2 while supplying an abrasive material tube. This j &
Book 1: Based on Kyoto theory (2: structure of the equipment used for this,
The operating conditions are not limited to 2. For example, the rotation method of the holder and the upper and lower polishing plates can be selected from #1, Free C2, and the processing @ lapping the surface.
Both methods can be applied to box finishing, and in extreme cases, chemical I: polishing with only liquid acting on the workpiece and electrolytic polishing I: can also be applied, and furthermore, the abrasive material is free. Of course, it can also be applied to the case where it is fixed to the surface of the foot.

Also, regarding the structure of the device, if there are two sections in Fig. 4 and the upper and lower surface plates have different sizes, for example, the diameter of the upper surface plate is small,
While rotating the upper surface plate, the entire surface of the holder is straight.The structure is such that the entire surface of the holder is moved evenly, and the surface plate is composed of a disk with a small diameter and revolves around the holder while rotating on its axis. Depending on the polishing conditions, the upper and lower surface plates 1 may have a concave or convex curved surface instead of being flat. Sarakoji: We have described the case where #1 holder is held horizontally and the workpiece is therefore finished flat (two-dimensional).
The method of the present invention can also be applied to the finishing of workpieces with curved surfaces; in this case, upper and lower surface plates, preferably t L < i
The lower leg i11 should have a curved surface exactly as shown in pJ'r, and the holder support stand and the holder should be devised so as to hold the holder along this surface.

[Brief explanation of the drawing]

1111-iM3 Figure t; All are for explaining the basic grooves of conventionally known polishing methods, and Figure 11,
Figure 2 is a schematic view of the main parts, showing a single-sided polishing method, and Figure 3 is a double-sided polishing method. Figures 4 and 5 show different examples of polishing equipment for carrying out the method of the present invention. (at kt important cross-sectional view, +bitX
FIG. 3 is a plan view showing the upper part of the holder with the upper surface plate removed. (Isamu 1 to 3) 1...Wafer to be polished, 2...Holder. 3.8. Q, 10... Polishing surface plate, 4... Demand for fixed feet. 5... Pad, 6... Wafer holding hole. 7...Number of possessions, 11...Career. 12... Ching gear, 1a... Internal gear. (Figure 4, Figure 5) 20.21... Polishing surface plate, 22... Holder. 23... Wafer to be polished, 24... Hole for holding the wafer to be polished. 25...Holder support base, 26...Tightening jig. Figure 1 Song 1 Figure 3 Figure 4 (a) (b) Figure 5 (a) (b)

Claims (1)

[Claims] 1. Rotation↑ゐC between upper and lower grinding banks: A holder having one or more holes for holding the workpiece is interposed, and the outer peripheral edge of the holder and /l A polishing method characterized by simultaneously polishing both surfaces of a workpiece housed or held in the holder by fixedly supporting the holder or the inner peripheral edge of the holder. 2. The polishing method as set forth in claim 1, characterized in that the upper and lower polishing surface plates and the holder are each rotationally driven.