JPH0413094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to, for example, silicon wafers used in semiconductor devices, GGG (Gadri gallium garnet) wafers used in bubble memory devices, digital magnetic heads, or MIC (microwave integrated circuit) elements. The present invention relates to a method for efficiently bonding a wafer or substrate, such as a ferrite substrate or a piezoelectric ceramic substrate used in a SAW (surface wave) filter, to a metal jig when double-sided polishing is performed.

Generally, this kind of wafer/substrate wrapping,
The polishing technique is an important point because it influences the characteristics and quality of the element or device obtained by subsequent processing. Furthermore, when mirror polishing a wafer/substrate, in addition to the flatness of the surface, the parallelism of both surfaces is also important.

Therefore, in order to achieve high quality workpieces of this type, the cut wafer/substrate is polished and then mirror-finished using diamond paste or the like as an abrasive. Specifically, as shown in FIG. 1, a metal rigid body 2 to which a work 1 such as a wafer or a substrate is bonded with adhesive is placed on a polishing surface plate 3 with the work surface facing, and This is often done by injecting diamond paste between the disk 3 and the rotating rigid body 2.

By the way, to polish both sides of workpiece 1,
The roughly polished workpiece is bonded to a heated rigid metal body using thermoplastic adhesive, one side is first polished, the rigid body is then heated, the workpiece is removed, and the workpiece is cleaned to remove any residue that has adhered to it. Next, the process from above is repeated with the side of the workpiece reversed.

However, when adhering workpieces by such a method, many man-hours are required for adhesion and peeling, and workability is extremely poor.

In view of the above, the present invention has been developed by rationally adhering and peeling a work to be polished to first and second rigid metal bodies coated with first and second adhesives having different softening points, respectively. The main purpose of this paper is to propose a workpiece bonding method that significantly reduces the number of man-hours required for this type of method.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a process diagram showing an example of the method of the present invention. 5 and 6 indicate first and second metal rigid bodies;
First and second adhesives 7 and 8 are applied to the surfaces to which the work is attached, respectively, and are heated in advance by a heating device 9 such as a hot plate. In this case, the first and second rigid bodies 5, 6 are heated by the heating device 9.
When the workpiece 10 is placed on the first adhesive 7 of the first rigid body 5 by setting the temperature of
0 becomes one with the first rigid body 5.

Next, as shown in Figure B, the second rigid body 6 is placed on the adhesive guide 11, and the first rigid body 5 is positioned and stacked so that the attachment surfaces face each other.
Therefore, the first rigid body 5 is integrated with the upper surface of the workpiece 10, and the second rigid body 6 is integrated with the lower surface.

Next, as shown in FIG. C, in order to cool only the second rigid body 6, by making it come in contact with the cooling water 14 filled in the water tank 13, the second adhesive 8 will quickly soften and bond to the workpiece 10. The workpiece 10 is separated from the first rigid body 5 by being firmly integrated with the second rigid body 6 and being pulled up above the first rigid body 5 together with the first adhesive 7 which is still in a softened state. (See figure D). Therefore, the opposite surface of the workpiece 10, which has been previously polished on one side, can be mirror-polished while being integrated with the second rigid body 6.

In this case, the softening points of the first adhesive 7 and the second adhesive 8 are set to be different. That is, the first
Adhesive 7 has a softening point of 50℃ pine resin wax (Nikka Seiko)
By using a similar resin (Stetuki Wax manufactured by Nikka Seiko Co., Ltd.) with a softening point of 60°C as the second adhesive 8, heating and cooling can be easily managed. It can be processed in a short time. Note that the above adhesive is an example, and other thermoplastic/thermosetting adhesives may be used.

In the above example, the moving direction of the first and second metal rigid bodies 5 and 6 was set up and down, but it is also possible to set it up and down, but also in the front-back or left-right direction.

As described above, according to the present invention, the workpiece is
A first rigid metal body bonded with an adhesive, and a second rigid metal body whose adhesive surface is coated with a second adhesive set higher than the softening point of the first adhesive and a step of heating the second adhesive to a temperature above the softening point, a step of stacking the work on a second adhesive surface of the second rigid metal body at a temperature above the softening point, and a step of stacking the workpiece on the second bonding surface of the second metal rigid body, and When the metal rigid body is cooled and the metal rigid body described above and the workpiece are bonded, the first
By removing the rigid metal bodies, the process can be completed in an extremely short time of approximately 8 minutes, compared to approximately 45 minutes using the conventional method, resulting in a significant increase in productivity. This is a significant improvement. Moreover, when transferring the workpiece from the first rigid body to the second rigid body, in the past, chipping and scratches of the abrasive product often occurred, resulting in a deterioration of the yield, but according to the present invention, such drawbacks can be eliminated. It has the effect of improving the yield with almost no generation.

[Brief explanation of drawings]

Figure 1 is a diagram used to explain the workpiece polishing method.
FIGS. 2A, B, C, and D are process charts showing an example of the present invention. 5... First metal rigid body, 6... Second metal rigid body, 7... First adhesive, 8... Second adhesive, 9... Heating device, 10... Work, 14 ……
Cooling water.

Claims (1)

[Claims] 1. A first rigid metal body to which a workpiece is adhered with a first adhesive, and a second adhesive set higher than the softening point of the first adhesive is applied to the adhesive surface. heating the second rigid metal body to a temperature above the softening point of the first and second adhesives; A workpiece comprising: a step of stacking the workpieces; and cooling the second rigid metal body and removing the first rigid metal body when the second rigid metal body and the workpiece are bonded to each other. Adhesion method.