JPS62255059A - Back damage device - Google Patents

Abstract

PURPOSE:To prevent environmental contamination and unnecessary abrasion and to obtain an N1 type simple structure in a back damage device for a silicon wafer, etc. by providing a rotatable chuck, grinding tape carrying means, pressu rizing means and swinging means. CONSTITUTION:A grinding tape 9 which is wound between winding reels 11, 12 and guided by guide rollers 13, 13 travels when a work 2 held by a chuck 3 is rotated by a motor 5. While a holder 17 descends through a guide 18 by a rod 16a of a pressurizing cylinder 16. Then the tape 9 is pressed against the work 2 by the action of a spring 20 of a pressurizing roller 19. The width of the tape 9 is somewhat wider than the radius of the work 2. The tape 9 is positioned eccentrically at one side of the work 2 and grinds the work 2, swinging horizontally along rails 22 by a driving source 23. Water is supplied from a water feeding pipe to the machined portion. There is no scattering of the particles and abrasion of unnecessary portions as separating grinding particles are not used. Thus, it is possible to make the structure of the present device simple and compact.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a back damage device for damaging the back surface of a workpiece such as a silicon wafer for the purpose of controlling crystal dislocations in a device active layer of the workpiece. be.

[Prior Art] In order to control crystal dislocations in a device active layer in a workpiece such as a silicon wafer, damage is caused to a certain depth on the surface opposite to the mirror surface of the workpiece, that is, on the back surface side.
It is well known that crystal dislocations on the device surface side can be reduced, and back damage treatment is applied to almost all workpieces by various methods such as shot blasting and lapping.

However, since the above-mentioned shot blasting method is a method in which abrasives are sprayed onto the workpiece together with high-pressure water, the abrasives often scatter to the surroundings, causing environmental pollution and unnecessary wear of parts. If such a configuration were to prevent such problems, the entire device would have to be large-scale.

Similarly, the lapping method uses loose abrasive grains, which causes scattering of the abrasive grains, resulting in contamination and abrasion of unnecessary parts.

[Problems to be Solved by the Invention] An object of the present invention is to provide a back damage device that does not cause scattering of abrasives, has a simple structure, and is small.

[Means for Solving the Problems] In order to solve the above problems, the back damage device of the present invention includes a rotatable chuck that holds a workpiece to be machined, a chuck whose width is larger than the radius of the workpiece, and a single-sided chuck. a polishing tape coated with abrasive grains; a transfer means for continuously transporting the polishing tape; and a pressure means for pressing the polishing tape against a radius of a workpiece held by a chuck. , and a swinging means for swinging the workpiece and the polishing tape relative to each other in the radial direction of the workpiece.

[Operation] When the co-work is held in the chuck with the side opposite to the mirror surface, that is, the back side facing out, the rotation of the chuck and the transfer of the polishing tape are started, and at the same time, the polishing is performed by the pressure means. tape is pressed against the workpiece. Furthermore, the polishing tape and the workpiece are relatively oscillatedly displaced in the radial direction of the workpiece by the driving means.

In this way, the workpiece comes into sliding contact with the abrasive tape while rotating, and the entire surface of the workpiece is uniformly processed, thereby receiving a predetermined back damage treatment.

At this time, since polishing is performed using fixed abrasive grains, there is no scattering of abrasive grains, and no environmental pollution or wear of unnecessary parts occurs.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, l is a machine body, and a rotatable chuck 3 that holds a workpiece 2 such as a silicon wafer by suitable means such as suction is disposed inside the machine body 1, and the chuck 3 is It is connected via a drive shaft 4 to a drive source 5 such as a motor.

A support frame 8 disposed on the machine body 1 includes a take-up reel 11, 12 around which both ends of the polishing tape 9 are wound, and a plurality of guide rollers 1 for guiding the transport of the polishing tape 9.
3,13. A transfer means 10 consisting of... is attached, and a pressure means 14 for pressing the polishing tape 9 against the work 2 is arranged at a position corresponding to the work 2 held by the chuck 3. It is set up.

As can be seen from FIG. 2, the polishing tape 9 has a width W
is formed to be slightly larger than the radius of the workpiece 2, one side of which is coated with abrasive grains, and placed at a position biased toward one side of the workpiece 2.

Further, the pressure means 14 for pressing the polishing tape 9 against the workpiece 2 is a pressure cylinder 1 fixed to the support frame 8.
The holder 1 is attached to the rod 1llia of No. 6 through the guide 18.
7 is attached to be movable up and down, and a pressure roller 19 having approximately the same length as the width of the polishing tape 9 is attached to this holder 17 in a rotary position, and the holder 17 is biased in the pressure direction by a spring 20. The abrasive tape 9 is pressed against the radius portion of the workpiece 2 by the biasing force.

The support frame 8 is a rail 2 fixed on the aircraft body.
2 in the width direction of the polishing tape 9, and is oscillated by a drive source 23 consisting of a cylinder or a motor. That is, the rail 22 and the drive source 23 constitute a swinging means 21 for the support frame 8.

Next, the operation of the back damage device having the above configuration will be explained.

First, the workpiece 2 is held by the chuck 3 with the surface opposite to the mirror surface, that is, the back surface thereof, facing outward.

At this time, the pressure roller 19 and the polishing tape 9 are on standby to be raised by the pressure cylinder 16.

Next, while rotating the chuck 3, the take-up reel 12
is rotated to transfer the polishing tape 9, and the pressure roller 19 is moved downward by the pressure cylinder 16 to press the polishing tape 9 against the workpiece 2. Furthermore, the support frame 8 is oscillated by the driving means 23, and the workpiece 2 and the polishing tape 9 are oscillated relative to each other in the radial direction of the workpiece 2. At this time.

For the part of the workpiece 2 to be processed by the polishing tape 9.

Water is supplied through a water supply pipe (not shown).

In this way, the workpiece 2 comes into sliding contact with the polishing tape 9 while rotating, and the entire surface of the workpiece 2 is uniformly processed, thereby being subjected to a predetermined back damage treatment.

The operation of the device described above can be automatically controlled by a control means such as a microcomputer.

[Effects of the Invention] As described above, according to the back damage device of the present invention, since the workpiece is polished with the polishing tape coated with abrasive grains, the abrasive grains are not used in the case where free abrasive grains are used. Processing can be carried out without causing any scattering of particles, environmental pollution, or abrasion of unnecessary parts.

In addition, since the polishing tape is simply pressed onto the workpiece, the structure of the device is simpler than the shot blasting method, in which high-pressure water is ejected from a nozzle, or the lapping method, in which a heavy surface plate is rotated. Can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a plan view of the main part thereof. 2 Lower work, 3... Chuck, 9... Polishing tape, 10... Transfer means, 14... Pressure means,
21... Swinging means.

Claims (1)

[Scope of Claims] 1. A rotatable chuck that holds a workpiece to be processed; an abrasive tape having a width larger than the radius of the workpiece and coated with abrasive grains on one side; and the above-mentioned abrasive tape. a pressure means for pressing the polishing tape against a radial portion of the workpiece held by the chuck; and a pressure means for relatively swinging the workpiece and the polishing tape in the radial direction of the workpiece. A back damage device comprising: a swinging means;