JPH0735016B2 - Wrapping method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lapping method for glass, ceramics, etc., which uses granite, which has a high effect of holding abrasive grains during processing, on a surface plate and has a high processing efficiency. Regarding

BACKGROUND ART Lapping is a lapping liquid containing abrasive grains having a required property as a free abrasive material, which is interposed between a processing surface plate (lap) serving as a polishing reference surface of a workpiece and the workpiece, It is processed by the relative movement of the two.
It is possible to machine the surface to a smooth finished surface with the correct dimensional accuracy, and it is possible to obtain the highest processing accuracy among the current mass-production processing methods.

For example, lapping is used for high precision processing of gauges such as block gauges, balls, lenses, optical products such as optical flats, or semiconductor electronic materials and ceramic electronic materials such as ferrites.

Problems of the prior art Since such lapping requires high polishing efficiency and good size and shape of the work material, the ability to hold the abrasive grains during polishing is required, and the properties and processing of the lapping liquid It was considered important to select a surface plate.

The characteristics of the material used for the lapping platen are that it is homogeneous and dense, that there are no scratches or inclusions, that it is difficult to wear unevenly to maintain the correct size and shape of the workpiece, It is required to have the ability to hold abrasive grains.

Conventionally, a metal material such as soft iron, copper, tin, or aluminum, or a non-metal wrap material such as raw glass or soda glass has been used as the material of the surface plate.

For example, the processing of ferrite material for magnetic heads requires precision laps such as mirror surface laps, and the sanding (WA, GC, etc.) polishing process is required as the pre-processing. Conventionally, raw glass containing SiO ₂ as a main component has been used as the material of the board.

However, lapping using a raw glass surface plate has a low polishing efficiency.

2. High consumption of abrasive grains (GC, WA, etc.).

3. The platen has a short life.

4. The platen material had drawbacks such as being expensive and difficult to obtain.

Object of the Invention This invention eliminates the drawbacks of conventional processing surface plates, glass, ceramics, precision processing of ferrite, etc., during sanding, the size of the workpiece, good shape, can be processed with high polishing efficiency, Further, another object of the present invention is to provide a lapping method for extending the service life of the processing surface plate.

SUMMARY OF THE INVENTION The present invention is a lapping method in which a lapping liquid containing abrasive grains is interposed between a processing surface plate, which serves as a polishing reference surface of a work piece, and the work piece, and the work is performed by relative motion of the two. The lapping method is characterized by using a surface plate composed of granite having a surface roughness of 2 μm or more.

Structure of the Invention In this invention, granite used for the processing surface plate is a general term for granite or a stone material similar thereto, and is roughly classified into white granite and black granite.

Granite is known as granular plutonic rock and includes potassium feldspar, albite, syenite feldspar, quartz, biotite, muscovite, etc. Depending on the content of quartz, potassium feldspar, and mica, the stones are gray, white, black, etc. The apparent color is decided.

Strictly speaking, black granite is a dioritic to gabbroic rock, which is different from granite, and is dark green to grayish black.

Diorite is a neutral plutonic rock from grey-green to dark green, with neutral plagioclase, amphibolite, and pyroxene as the most common main components.
Gabbro is composed of plagioclase with high calcium content and pyroxene as the most common main component ore, and may also contain olivine and amphibolite as main components.

Such granite is abundant in nature, and granite has many other uses, but when used in the present invention, if a diameter of several hundred mm and a thickness of several tens of mm can be taken. Since it is sufficient, it can be easily obtained. The granite used in the present invention may be white granite or black granite, but black granite is not so hard and is preferable as a material for the surface plate.

For the surface plate according to the present invention, granite is cut into, for example, several hundreds of mmφ and several tens of mm in thickness, and the surface is polished by a master lap or the like to have a surface roughness of 2 to 20 μm.

In the present invention, granite, since the particles that make up the stone are non-uniform, the portion vulnerable to abrasion during processing is worn or dropped first, and this portion becomes an abrasive grain pool during polishing. Therefore, it is considered that it has a remarkable effect on the retention of the abrasive grains during processing.

Therefore, when the surface roughness is less than 2 μm, there is no effect of accumulating abrasive grains during processing, and when it exceeds 20 μm, chipping or the like is generated at the edge of the workpiece, which is not preferable. It is preferable that the surface roughness of the surface plate is 3 μm to 10 μm in order to obtain a processed surface with high accuracy.

The work piece can be applied to glass, various ceramics, alloys by powder metallurgy, etc., but ceramics such as ferrite and Ti—Ba porcelain are particularly suitable.

Further, as the lapping agent, GC # 1500 to 6000 abrasive grains are preferable.

EFFECTS OF THE INVENTION In the lapping according to the present invention, since the material of the surface plate is not harder than that of the conventional material, the processing is easy and the surface plate having a stable flat surface can be easily prepared.

Furthermore, regardless of the type of the lapping liquid, scratches and the like are unlikely to occur on the finished surface of the processed surface, and the processing efficiency is good.

Further, the consumption of abrasive grains such as WA and GC used during polishing is drastically reduced, and the cost required for processing is reduced.

Examples Hereinafter, the present invention will be described in detail with reference to Examples.

A 380 mmφ × 25 mmt surface plate was made using raw glass and black granite. Using this surface plate, 9 × 34 × 1.2t Mn-Zn ferrite as a work was radially attached to the work attachment disk of 180 mmφ, and 31 pieces were radially attached to the attachment disk.

GC # 3000 was used as the abrasive grains, and processing was performed under the processing pressure of 50 g / cm ² . Table 1 shows the results of processing the lapping allowance of 15 μm.

As is clear from Table 1, by the lapping of the present invention, the grindstone supply amount was 72% of the conventional amount, the processing time was shortened to 61%, and the processing efficiency was increased to 165% accordingly.

Claims (1)

[Claims] 1. A lapping method in which a lapping liquid containing abrasive grains is interposed between a work surface plate serving as a polishing reference surface of a work piece and the work piece, and the work is performed by relative movement of the two. A lapping method characterized by using a surface plate composed of granite having a roughness of 2 μm or more.