JPS63127870A - Polishing method - Google Patents

Abstract

PURPOSE:To aim at enhancing the dimensional accuracy and geometrical accuracy of a workpiece in a polishing method of such as a VTR head, by bonding the workpiece on an applying type stool through the intermediary of thermo- softenable adhesive and uniform shape balls or cylinders. CONSTITUTION:A thin layer of thermo-softenable adhesive 3 such as electron wax or the like is coated on an applying type stool 1, and a suitable number of spherical or cylindrical spacers 13 having a uniform size of several mum to several tenth mum and made of resin, are set thereon. Then, the workpiece 2 is stretched by being manually retained, or by, if necessary, being retained with the use of a weight 4 so as to be bonded to the stool so that the adhesive 3 layer has an uniform thickness. Therefore, polishing is made. Thus, it is possible to bond the workpiece onto the stool 1 with the dimensional accuracy of about + or -0.4 mum, and therefore, it is possible to adjust the thickness of the adhesive layer with a high degree of accuracy which is higher than that of conventional methods by one order, thereby it is possible to polish a workpiece with high dimensional accuracy and geometrical accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to polishing of a workpiece, and particularly to a polishing method that provides high dimensional accuracy and shape accuracy.

[Conventional technology]

Many of the recent electronic and optical components require high dimensional and shape accuracy. For example, when polishing a VTR head to increase its thickness, it is required to polish a chip several mm square with a dimensional accuracy of ±3 μm or less. In addition, as the recording density of computer heads continues to increase, the required accuracy also increases, and in some cases, dimensional accuracy of 1 μm or less is now required.

Fig. 2 is a cross-sectional view showing the conventional bonding method for workpieces as disclosed in, for example, JP-A-52-144900, Fig. 3ryI is a plan view of a sizing jig used for polishing, and Fig. 4 is its front view. FIG. 5 is a front view showing the polishing state.

In the figure, (1) is the pasting surface plate, (2) is the workpiece, (
3) is a heat-softening adhesive, (4) is a weight, (5) is a metal bottom plate, (6) is a ceramic ring made of alumina or other material that is generally difficult to polish, (7) is a mounting surface plate fixing screw, (8) ) is the spring, (9) is the attachment surface plate positioning adjustment screw, (10) is the workpiece processing surface, (11) is the end face of the ceramic ring (6), and (12) is the workpiece processing surface (10). This is a step between the ceramic ring (6) and the end surface (11), that is, a polishing margin.

In conventional polishing methods, when high dimensional accuracy is required, workpieces have been bonded using a method as shown in FIG. In other words, the workpiece (2) is pressed onto the pasting surface plate (1) with a heat-softening adhesive (3) such as electron wax by hand so that the adhesive is as thin and uniform as possible. In Part 7, adhesive was applied by applying pressure with a weight (4).

Next, the pasting surface plate (1) to which the previously prepared workpiece (2) is adhered is set on the sizing jig as shown in FIG. 3 as shown in FIG. 4. In this case, use the attachment surface plate fixing screw (
7), set the desired polishing allowance (12) using the adjustment screw (9) and perform polishing. When the polishing allowance (12) becomes zero, Polishing is completed.

[Problem that the invention seeks to solve]

However, in the above case, due to the non-uniformity of the thickness of the adhesive (3) layer at the time of adhering the workpiece (2) in FIG.
An error of about 3 μm always occurs. Further, in polishing using the sizing jig shown in FIGS. 3 to 5, an error of about 1 μm cannot be denied, and therefore, there is a problem that a total dimensional error of about 4 μm occurs.

It is an object of the present invention to provide a polishing method that eliminates the above-mentioned problems and provides high dimensional and shape accuracy.

[Means for solving problems]

The polishing method of the present invention is a method in which a workpiece is adhered to a mounting surface plate via a heat-softening adhesive and a spacer having a uniform shape, and then polished.

[For production]

In the polishing method of the present invention, a workpiece is adhered to a mounting surface plate via a heat-softening adhesive and a spacer having a uniform shape, and then polished. At this time, the workpieces are adhered to the attachment surface plate using a heat-softening adhesive while maintaining a constant distance using spacers, and the thickness of the adhesive layer becomes uniform, thereby increasing the adhesion accuracy of the workpieces. , processing can be performed with high finishing dimensional accuracy and shape accuracy.

〔Example〕

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

FIG. 1 is a cross-sectional view showing the bonding method of the present invention.

In the figure, the same or corresponding parts as in FIG. 2 are given the same reference numerals. (13) is a spacer having a uniform shape and size, such as a sphere or a cylinder.

The bonding method will be explained with reference to FIG. Apply a thin layer of heat-softening adhesive (3) such as electron wax on the attachment surface plate (1), and then attach a ball or cylinder made of resin or the like with uniform dimensions over several micrometers to several 10 micrometers. Place an appropriate number of spacers (13). Thereafter, the workpiece (2) is pressed and stretched by hand so that the thickness of the adhesive (3) layer becomes uniform, or in some cases, it is pressed with a weight (4) for bonding. The subsequent polishing method is the same as the conventional method.

Here, Table 1 shows how specifically the variation in the thickness of the adhesive layer is reduced. Table 1 shows the results of bonding the block gauges several times with electron wax, and the adhesive layer thickness was determined from the difference between the thickness of the block gauges before bonding and the thickness of the block gauges after bonding.

From Table 1, it can be seen that no matter which spacer is used, bonding is possible with a dimensional accuracy of ±0.4 μm.

This value is a standard deviation of 0.35μm for a spherical 5μ layer spacer.
This value is very close to that of the conventional method, and it is possible to control the adhesive layer thickness with an order of magnitude higher precision than before, so it is possible to fully meet the demands for high precision in electronic components, optical components, etc.

Although electron wax was used in the above embodiment, any heat-softening adhesive may be used, and the size and shape of the spacer are not limited. Further, as a bonding method, a spacer may be mixed in advance with an adhesive, and the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, by inserting a spacer into the heat-softening adhesive, the thickness of the adhesive layer can be rolled with high accuracy, and polishing can be performed with high dimensional and shape accuracy. There is.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a method for bonding workpieces according to an embodiment of the present invention, FIG. 2 is a sectional view showing a conventional method for bonding workpieces, and FIG. 3 is a plan view of a sizing jig. FIG. 4 is a front view thereof, and FIG. 5 is a front view showing the polished state. (1)... pasting surface plate, (2)... workpiece, (3)
... Heat softening adhesive, (4) ... Weight, (13)
···Spacer. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A polishing method characterized in that a workpiece is bonded to a mounting surface plate via a heat-softening adhesive and a spacer of a uniform shape, and then polished. (2) The polishing method according to claim 1, wherein the spacer is spherical or cylindrical.