JPH05285812A - Grinding method - Google Patents

Abstract

PURPOSE:To provide a grinding method capable of acquiring finished surfaces high in precision and quality and of improving grinding work efficiency. CONSTITUTION:Under a method to flatly grind a workpiece by using a straight type grinding wheel or a cup type grinding wheel, the workpiece is ground by supplying a grinding liquid suspending polishing abrasive grains smaller than grinding abrasive grains in grain diameter or polishing abrasive grains which are crushed smaller than the grinding abrasive grains during the time of grinding. The fine polishing abrasive grains work on a microscopic area of a ground surface and remove a material a microscopic amount each. Consequently, a streak and a processed distorted layer made by grinding process are removed without damaging surface quality. Additionally, the grinding liquid dissolves and removes grinding dusts attached to the grinding surface of the grinding wheel during the time of grinding work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding method, and more particularly to a surface grinding method.

[0002]

2. Description of the Related Art Generally, in grinding, in order to grind a workpiece with high efficiency and high precision, the grinding is performed while supplying a grinding liquid to a contact portion between a grinding wheel and the workpiece.
The grinding liquid is required to have corrosion resistance, cooling property, lubricity and the like. Such a grinding fluid contains mineral oil, animal or vegetable oil, ester oil, or a surfactant as a main component, and may include an extreme pressure additive or the like.

[0003]

Generally, in the grinding process,
The workpiece surface is machined by the mechanical cutting action of the abrasive cutting edge. For this reason, in the grinding process using the conventional grinding fluid as described above, residual scratches and machining strains cannot be avoided. Therefore, the surface roughness of the ground surface is large, and the relaxation of residual strain causes secular change in shape and dimension.
The quality of the finished surface deteriorated.

Further, in the conventional grinding work using a grinding liquid, clogging is likely to occur. Therefore, the grinding wheel has to be dressed frequently, which has been a cause of a reduction in the efficiency of the grinding work.

The present invention is intended to provide a grinding method capable of obtaining a high-precision and high-quality finished surface and improving the grinding work efficiency.

[0006]

The grinding method of the present invention comprises:
In a method of surface grinding a workpiece using a straight grindstone or a cup grindstone, a grinding grain having a grain size smaller than that of the grinding grain or grinding that is crushed smaller than the grinding grain during grinding is suspended. Liquid is supplied to grind the workpiece.

As the abrasive grains of the grinding wheel, conventional abrasive grains such as diamond, CBN, WA, and GC are used. Further, as the bonding material, a usual bonding material such as vitrified, resinoid, metal or the like is used.

As the above-mentioned polishing abrasive grains, there are an abrasive used for polishing a workpiece, fine abrasive grains close to polishing, or abrasive grains having a hardness similar to that of the workpiece or a soft abrasive grain. In the case of abrasive grains that have the same hardness or softness as the work piece, even if some of these abrasive grains have a larger grain size than the abrasive grains, they will be crushed into fine grains during grinding. .. The particle diameter of the abrasive grains or the crushed abrasive grains is preferably about 0.01 to 10 μm. As these abrasive grains, for example, SiO
₂ powder, BaCO ₃ powder, Cr ₂ O ₃ powder and Fe ₂ O ₃
There are powders. As a working fluid that suspends abrasive grains,
Water or an alkaline solution such as KOH aqueous solution is used. Further, the working fluid may be one that exhibits a chemical action such as etching.

The temperature of the polishing agent is preferably 20 to 50 ° C.

The grinding method may be a rotary grinding method using a cup type grindstone or a reciprocating grinding method using a straight type grindstone.

[0011]

The released fine abrasive grains roll or slide on the ground surface. The protrusion on the ground surface caused by the grinding is destroyed by the collision of the polishing abrasive grains. The fine abrasive grains act on a very small area of the ground surface and remove the material in minute amounts. As a result, the scratches and processing strain layer generated by the grinding process are removed without impairing the surface quality.

Further, the grinding liquid having a chemical action dissolves away the grinding dust attached to the grinding surface of the grindstone during the grinding operation.

[0013]

Example A silicon wafer was ground with a diamond grinding wheel. The average diameter of diamond abrasive grains is 5 μm
And the volume ratio is 30%. The grinding liquid is a suspension of fine silica powder in a KOH aqueous solution. The average particle size of the silicon fine powder is 0.05 μm. Wheel peripheral speed is 1700 m / min, depth of cut is 0.002 mm / pass
Met. As a result of grinding under the above conditions, the surface roughness Ra was 0.
The residual strain was 003 μm and the residual strain was 0. Also, 2
It was possible to continuously grind for 0 hours without dressing.

As a comparative example, a silicon wafer was ground using a conventional grinding fluid, mineral oil, under the same grinding conditions as described above. As a result, the surface roughness Ra was 0.009 μm and the residual strain was up to a depth of 0.3 μm. Also,
I had to dress every 1.5 hours.

[0015]

EFFECTS OF THE INVENTION In the present invention, since fine abrasive grains act on a very small area of the ground surface to remove the material in minute amounts,
The streaks and work strain layers generated by the grinding process are removed without impairing the surface quality. As a result, high precision,
High quality finished surface is obtained. In addition, since the grinding fluid dissolves away the grinding debris adhering to the grinding wheel grinding surface during grinding work, it is possible to perform stable and long-term grinding work without frequent dressing. It is possible to improve efficiency.

Claims (1)

[Claims] 1. A method of surface grinding a workpiece using a straight grindstone or a cup grindstone, wherein the abrasive grains have a grain size smaller than that of the abrasive grains or are crushed smaller than the abrasive grains during grinding. A grinding method, characterized in that a grinding liquid is suspended to grind a workpiece.