JPH0234736B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wafer holding chuck assembly used in positioning a wafer workpiece on a mounting plate of a finishing device, and more particularly to a wafer holding chuck assembly for batch polishing. Concerning solids.

[Conventional technology]

In conventional finishing equipment for wafer-type workpieces, which are usually held in a relatively stationary position relative to a rotating finishing lap plate, the wafer workpiece is rotated by a workpiece holding device or, in the case of batch polishing, It was held in place by a template with a plurality of wafer receiving recesses or punch areas. For example, a resilient support or support pad was required that was adapted to accommodate the backside conditions of a lightly etched, ground, or sawed wafer. The elastic support required a composition with a thickness of 20-40 mils and was adhered to the wafer holding chuck or template of the finishing equipment.

[Problem that the invention seeks to solve]

The thickness of the elastic support, and therefore its inherent elasticity, resulted in a loss of precision in the flatness of the surface of the wafer being polished. This resulted in the workpiece being unacceptable and much of it being discarded.

On the other hand, in the prior art, when the elastic pad was damaged, the elastic pad had to be removed and the entire wafer holding chuck replaced.

It is an object of the present invention to provide a support for wafer-type workpieces, which is particularly applicable to wafer holding chuck assemblies for batch polishing, and which has inherent hardness and elasticity. The object is therefore to be able to hold the workpiece in the correct position for finishing without losing the flatness and/or tolerances necessary to obtain an acceptable finished product.

[Means for solving problems]

A wafer holding chuck assembly constructed in accordance with the present invention is a wafer holding chuck assembly used in positioning a thin wafer workpiece onto a mounting plate of a finishing equipment, the wafer holding chuck assembly being constructed in accordance with the present invention. a removable circular support member on which a removable circular support member is placed, and a spray is applied to said support member to coat the opposite surface of the thin wafer workpiece while the surface to be finished is being finished by the finishing device. a wafer support surface of rubber-like plastic material for resilient and resilient contact; a plurality of wafer support surfaces supported by said support member and for receiving and holding a thin wafer workpiece to be finished; a plastic template with a circular punching area;
a double-sided adhesive sheet interposed between the template and the support surface of the support member for removably attaching them to each other; a plurality of circular die-cut areas corresponding to and aligned with the circular die-cut area and not in contact with the wafer workpiece held within the circular die-cut area; It is characterized in that it is smaller than the thickness of the wafer to be finished, such that the surface to be finished of the workpiece lies in a high plane with respect to said template.

〔Effect of the invention〕

In the wafer holding chuck assembly of the present invention having the above configuration, the unpolished surface of the wafer is firmly and elastically supported by the wafer support surface of the support member, and a plurality of wafers are held in the circular shape of the template corresponding to the non-polished surface of the wafer. The wafer can be held within the punching area, thereby eliminating the need for the use of prior art elastic pads.
The desired flatness of the wafer can then be achieved.

〔Example〕

Referring to FIG. 1, a finishing or polishing device utilizing the wafer retaining chuck assembly of the present invention is indicated at 10. The polishing device 10 has a base 11 supporting a horizontally arranged apron 12. The polishing device is also an apron 12
It has a rotatable or immovable mounting plate 13 surrounded by. A wafer retaining chuck assembly 35 according to the present invention is securely and removably disposed on the mounting plate 13. The structure of this wafer holding chuck assembly 35 will be explained in detail later with reference to FIG.

With continued reference to FIG.
is supported by and extends vertically from the apron 12, with side arms 15 attached to this post.
One end of the is attached. At the other end of the side arm 15, a disc-shaped polishing lapping plate 17, preferably having a diameter approximately the same as that of the mounting plate 13, is rotatably mounted above the mounting plate 13 via a rotating shaft 16. In the case of a mounting board, it is mounted so as to be freely rotatable in the direction opposite to the rotational direction of the mounting board.

Referring to FIG. 2, the batch polishing wafer retaining chuck assembly 35 of the present invention includes a circular support member 33 adapted to be securely and removably placed on the mounting plate 13 of the finishing equipment, and a wafer retaining chuck assembly 35 of the present invention. a plastic template 29 formed with a plurality of wafer-receiving recesses or circular punched areas 30 adapted to receive and retain the same, and for supporting said template and the unpolished side of the wafer. A double-sided adhesive sheet 31 is provided between the support member 33 and one wafer support surface 34 for removably attaching them to each other.

Adhesive sheet 31 conforms to the shape of template 29 and is provided with a plurality of wafer receiving recesses or circular punched areas 32 similar to the circular punched areas of the template. As shown in FIG. 2, the circular punched areas 32 of the adhesive sheet 31 are configured and arranged to correspond to and align with the circular punched areas of the template 29, but preferably within the circular punched areas 30 of the template 29. The diameter of the wafer is such that it does not come into contact with the wafer workpiece held by the wafer. The sum of the thicknesses of template 29 and adhesive sheet 31 is less than the thickness of the wafer to be finished so that the surface of the wafer workpiece to be polished lies in a higher plane than the template.

The wafer support surface 34 of the support member 33 is spray coated with a rubber-like plastic material to provide a firm yet resilient wafer support surface to the unpolished side of the workpiece.
The thickness of the coating layer may range from 25.4 to 127.0 microns (1 to 5 mils) depending on the wafer to be polished. Depending on its formulation and coating thickness, the spray coating constitutes a firm yet resilient support element that supports and protects the unpolished side of the silicon wafer during finishing operations. Support element 34 of this rubbery plastic material
This eliminates the need for a separate elastic pad as used in the prior art. The spray coating is applied uniformly, and if there is a risk that the spray coating support element will be scratched or broken by facing a chipped or cracked wafer, the spray coating support element should be aligned in the desired plane. It is best to finish it once. The rubbery plastic spray coating provides a more uniform and planar support element that allows the wafer to be polished to maintain proper flatness, thus producing an acceptable wafer.

In some cases, it has the form of a support member 33,
and a mylar sheet that is removably attached to the support member 33 with double-sided adhesive tape,
It is desirable to apply a rubbery plastic spray coating to the exposed surfaces of the Mylar sheet. By this,
The rubber-like plastic support element can be easily removed and replaced when required.

Although preferred embodiments of the invention have been described, modifications may be made thereto without departing from the scope of the invention. Therefore, various modifications can be made within the technical scope of the claims without being limited to the configuration described above.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a polishing device in which a batch polishing wafer holding chuck assembly of the present invention is arranged, with the thickness of the components of the wafer holding chuck assembly exaggerated for clarity. FIG. FIG. 2 is an exploded perspective view of the wafer holding chuck assembly for batch polishing of the present invention. [Explanation of main reference numbers], 10...polishing device,
29...Template, 30, 32...Circular punching area, 31...Adhesive sheet, 33...Support member, 34...Support surface, 35...Wafer holding chuck assembly.

Claims (1)

[Claims] 1. A removable circular support member for use in positioning thin wafer workpieces on the mounting plate of a finishing apparatus, the wafer holding chuck assembly being adapted to rest on the mounting plate 13 of the finishing apparatus 10. 33, while the support member is being sprayed and the surface of the thin wafer workpiece to be finished is being finished by a finishing device;
a wafer support surface 34 of a rubber-like plastic material for firm and resilient contact with the opposite surface; a plastic template 29 with a plurality of circular die-cut areas 30 for holding the wafer, and a double-sided adhesive sheet 31 interposed between said template and said wafer support surface for removably attaching them to each other.
and the adhesive sheet 31 has the circular punched area 3 formed in the template 29.
0 and aligned with the circular die-cut areas and not in contact with the wafer workpiece held within the circular die-cut areas, the thickness of the template 29 and the adhesive sheet 31 is less than the thickness of the wafer to be finished such that the surface of the wafer workpiece to be finished lies in a high plane with respect to said template.