JPH09254146A - Cutting or grooving method of hard brittle material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool shape and processing conditions suitable for improving processing efficiency more than in a fixed abrasive grain method whose cutting efficiency has been considered to be excellent conventionally, in a processing method to be adapted to cutting processing and grooving processing of a hard brittle material. SOLUTION: By using a fixed abrasive grain tool having a linear blade shape being held by a plating layer 13 formed by electrodeposition of a fixed abrasive grain 12 on a surface of a thin plate metallic base material 11, processing is performed by supplying, to a processing section, a processing liquid in which a free abrasive grain 32 having a diameter smaller than a protruded height H of the fixed abrasive grain from the plating layer 13 of the fixed abrasive grain tool is mixed. For the fixed abrasive grain 12, a diamond abrasive grain is used. For the plating layer 13, a nickel plating layer is suitable. Also, by performing processing by adding relative vibration in a cutting direction of a blade-like tool to a work, processing efficiency is further improved and cut curving can be prevented. According to the above-mentioned method, processing efficiency at the time of continuous processing of a large number of works can be largely improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method applied to cutting or grooving a hard brittle material such as ceramics or silicon used for manufacturing a semiconductor device, and a blade or wire-shaped base material. The present invention relates to a method for processing a hard brittle material using a fixed abrasive tool having abrasive particles fixed on the surface.

[0002]

2. Description of the Related Art Silicon used as a material for electronic devices is much harder and more brittle than metals. As a processing method for accurately processing such a hard brittle material,
Abrasive processing using diamond abrasive is widely performed. For the abrasive grain processing, use a tool that does not have abrasive grains,
There are a free-abrasive grain method that is performed while supplying a working liquid in which abrasive grains (free abrasive grains) are mixed to a working tool, and a fixed-abrasive method that performs processing by using a tool with the abrasive grains fixed. Conventionally, the free-abrasive grain method, in which tools and devices are inexpensive, has been the mainstream, but recently, the fixed-abrasive grain method, which is excellent in machining efficiency, has been attracting attention. The tool shape is mainly a blade or a wire, and an inner peripheral blade cutting using the inner circumference of a ring-shaped blade, a multi-saw using a plurality of juxtaposed blades or wires, and the like are often used.

On the other hand, in the correction processing (dressing) of the lap surface of the lapping machine, a correction grindstone in which fixed abrasive grains are fixed by a plating layer is used, and dressing is performed while supplying a working fluid in which free abrasive grains are mixed to the surface of the lap. A method of performing the above has been proposed by the inventors of the present invention (Japanese Patent Laid-Open No. 8-
19959). However, what has been conventionally used as an abrasive grain processing method for hard brittle materials is the fixed abrasive grain method and the free abrasive grain method described above. There is no known processing method that uses grains together.

[0004]

SUMMARY OF THE INVENTION The inventors of the present invention have applied a machining method using fixed abrasive grains and free abrasive grains to cutting or grooving a hard brittle material. It has been found that the machining efficiency, especially the machining efficiency when a large number of workpieces are continuously machined, is greatly improved by cutting or grooving.

Therefore, the present invention provides a method for cutting or grooving a hard brittle material which can further improve the processing efficiency as compared with the fixed-abrasive method which was conventionally considered to have better cutting efficiency than the free-abrasive method. The problem is to provide a suitable tool shape and machining conditions for that purpose.

[0006]

A method of cutting or grooving a hard brittle material according to the present invention is a straight blade shape in which fixed abrasive grains 12 are held by a plating layer 13 electrodeposited on the surface of a thin metal base material 11. The fixed abrasive grain tool 1 is used, and the protruding height H of the fixed abrasive grain from the plating layer 13 of the fixed abrasive grain tool in the processing portion is H.
It is characterized in that the processing is performed while supplying the processing liquid in which the loose abrasive grains 32 having a smaller diameter are mixed.

Diamond abrasive grains are used as the fixed abrasive grains 12, and a nickel plating layer is suitable as the plating layer 13 for holding the abrasive grains. Further, by performing cutting or grooving while applying relative vibration in the cutting direction of the blade-shaped tool 1 to the work, the machining efficiency can be further improved and the bending can be prevented.

[0008]

In the first stage of processing, the fixed abrasive grains 12 mainly perform the cutting, and the processing efficiency equivalent to that of the fixed abrasive method is realized. When the cutting edge of the fixed abrasive 12 becomes worn due to the repeated machining, the protruding height of the fixed abrasive 32 from the plating layer 13 becomes low, and the gap between the surface of the plating layer and the work 3 becomes narrow. Since the free abrasive grains 32 in the working liquid are held in the narrowed gap, the free abrasive grains 32 compensate for the reduction in the cutting force of the fixed abrasive grains 12, and the plurality of workpieces The processing efficiency after processing is greatly improved compared to the conventional fixed abrasive grain method. Further, since a blade-shaped tool having a certain width is used, it is possible to continuously and efficiently process a large number of works without cutting the tool early like a wire.

In cutting or grooving a hard brittle material using fixed abrasive grains, by performing the cutting while applying vibration in the cutting direction to the work, it is possible to improve the processing accuracy and the processing efficiency and It is also known to be effective in prevention. This technique can also be applied to the method of the present invention, and in particular, a machining apparatus having a simple structure can be used by performing machining while applying vibration to the workpiece in the cutting direction of the blade-shaped tool (vertical direction in FIGS. 1 to 3). It is possible to further improve the processing efficiency and processing accuracy.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The tool 1 used for machining is shown in FIGS.
As shown in FIG. 3, a cutting edge 14 in which diamond abrasive grains 12 are fixed by a nickel plating layer 13 is provided on the lower side of a base material 11 made of a thin and long strip (thickness 0.5 mm, vertical width of 50 mm in the figure) strip steel plate. It is provided.

FIG. 4 shows an apparatus for electrodepositing diamond abrasive grains on the base material 11. The abrasive grain case 22 filled with the diamond abrasive grains 23 is immersed in the plating solution in the plating tank 21. The diamond abrasive grains 23 are fixed to the lower side of the base material 11 by nickel-plating the base material 11 held in the case with the lower side buried in the abrasive grains 23. An opening 24 is provided on the side surface of the abrasive grain case 22,
A cloth 25 is stretched over this opening to allow the plating solution to pass through and prevent the abrasive grains 23 from flowing out. Opening 2
On both sides of No. 4, nickel plates 26 serving as electrodes are arranged.

The tool blade 1 manufactured in this way
2 is a side view and FIG. 3 is an enlarged end view. The diamond abrasive grains 12 are in a state in which the portion on the base material 11 side is embedded and fixed in the nickel plating layer 13. Fixed diamond abrasive grains are 140-170 (particle size 8
8 to 105 μm).

The blade 1 is pre-plated and post-plated before and after the abrasive grains are electrodeposited by the apparatus shown in FIG. The post-plating is effective for burying the base of the abrasive grains fixed to the blade deeply in the plating layer to ensure the fixation of the abrasive grains.

The blade 1 manufactured in this manner is stretched on a tool table which reciprocates by a rotary sliding mechanism, and has a width of 25.
FIG. 5 shows the result of repeatedly processing (grooving) soda glass of mm. Processing load is 7.35 per blade
N, the stroke of the blade is 110 mm, the number of reciprocating revolutions is 100 rpm, and the machining efficiency (mm / mi) is calculated from the machining amount (cutting depth, unit mm) after machining for 8 minutes.
n) was calculated. The working fluid supplied to the cutting part was a working fluid (slurry) containing 30% by weight of free abrasive grains, and tap water was used as the working fluid in the conventional method for comparing the difference in working efficiency. . As the working liquid containing loose abrasive grains, the roughness of the loose abrasive grains is No. 1500 (particle diameter of about 10 μ, as shown in FIG.
No.), No. 1000 (about 15μ, black circle), 800
No. (about 18μ, half black and white circle) and No. 600 (about 25μ,
Four types of white triangle mark) were used. The results of the conventional method using tap water are indicated by black triangles in the figure.

From FIG. 5, a comparison will be made between a processing method using both fixed abrasive particles and free abrasive particles (hereinafter referred to as “mixing method”) and a processing method using only fixed abrasive particles (hereinafter referred to as “fixed abrasive particle method”). And the processing efficiency of the first processing is 3.75 mm
Although there is not much difference before and after / min, the machining efficiency of the fixed abrasive method sharply decreases as compared with the mixed method as the number of machining increases, and the machining efficiency becomes 0.125 mm / min or less after about 40 times. There is. On the other hand, the mixing method has a gradual decrease in the processing efficiency and has a substantially constant value after about 80 times of processing, and thereafter keeps the value. In the mixed method, since the free abrasive particles are present in the processing part, the fixed abrasive particles do not become clogged, and the fixed abrasive particles act as a holder for the free abrasive particles. It is considered that the reduction in processing efficiency is reduced compared to the above.

Further, in the mixing method, even if the particle size of the loose abrasive grains mixed in the working fluid is different, there is not much difference in the first time, but thereafter, the larger the free abrasive grain size, the more gradual the reduction of the working efficiency. Is. As the particle size of the loose abrasive grains increases, the processing amount per abrasive grain increases. When the fixed abrasive is worn, as shown in FIGS. 1A to 1C, a gap 31 between the plating layer 13 of the tool and the workpiece 3 (the protruding height of the fixed abrasive from the plating layer) A) Abrasive grains 32 present in
Is easily held by the fixed abrasive grains 12,
It is considered that the loose abrasive grains 32 held in the gap greatly contribute to the processing.

FIG. 1 shows that as the diamond abrasive grains 12 fixed to the tool 1 are worn, the loose abrasive grains 32 in the working fluid are more likely to be held between the nickel plating layer 13 of the tool and the workpiece 3. As shown, in the state of (a) where the number of cuttings is small, the gap 31 between the surface of the plating layer 13 and the surface of the workpiece 3 is large, and the loose abrasive grains 32 float with the machining liquid, resulting in much machining. While it does not contribute to the efficiency, in the state shown in FIG. 3C in which the fixed abrasive grains 12 are worn, the gap 31 between the surface of the plating layer 13 and the surface of the workpiece 3 becomes narrow, and the machining liquid enters this gap. It is understood that the free abrasive grains 32 therein are retained and contribute to the machining efficiency. The action of such free abrasive grains 32 is more effective as the particle size of the free abrasive grains 32 is larger, but the particle size of the free abrasive grains 32 is larger than the protruding height H of the fixed abrasive grains 12 from the nickel plating layer 13. If it is large, the cutting action of the fixed abrasive 12 is hindered, so that the machining efficiency is rather reduced.

As described above, when the cutting or grooving process of the conventional fixed abrasive method is compared with the cutting or grooving process of the method of the present invention (the above mixing method), there is no significant difference in the working efficiency at the initial cutting stage. However, there is a remarkable difference in the degree of reduction of the working efficiency when one tool is repeatedly used, and the working efficiency when continuously cutting a large number of hard and brittle materials is the same as that of the conventional fixing method. It is much more efficient than the abrasive grain method.

FIG. 6 shows that in the processing using a processing liquid containing loose abrasive grains having a grain size of 1500, the above-mentioned post-plating of the tool is performed for 30 minutes (white circles in FIG. 6), 40 minutes (black circles) and 50 minutes ( The relationship between the number of times of machining (horizontal axis) and the machining efficiency (vertical axis) was measured for the three types of tools that were used. As is clear from FIG. 6, the processing efficiency is generally improved in the case where the post-plating is performed longer, that is, the case where the plating layer is thicker. This means that a tool which has a large thickness of the plating layer, and therefore has a narrow gap between the surface of the plating layer and the surface of the workpiece, has been subjected to a large amount of post-plating. Similar to the explanation given in 1., the retention of loose abrasive grains between the surface of the plating layer and the workpiece is good, and it is considered that the machining efficiency is improved, which is consistent with the consideration of the action of the loose abrasive grains described above.

[0020]

As shown in the above test results, in cutting or grooving a hard brittle material, a fixed blade-shaped fixed abrasive tool in which fixed abrasive particles are fixed to the cutting edge portion by a plating layer is used. , The machining efficiency of the tool after multiple machining is conventionally achieved by supplying machining fluid containing free abrasive grains with a grain size smaller than the protruding height of the abrasive grains fixed to the tool to the machining section. This is far higher than the machining efficiency of the fixed abrasive grain method, and the number of workpieces that can be machined efficiently with one tool is increased. It should be noted that the one using a wire as a base material has a short tool life and causes wire breakage before cutting a large number of works, and therefore is not suitable for the tool of the method of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the action of loose abrasive grains in the method of the present invention.

[Fig. 2] Side view of a fixed-abrasive tool

FIG. 3 is an enlarged sectional view of a fixed abrasive tool.

FIG. 4 is an explanatory view of an electrodeposition device for abrasive grains on a tool.

FIG. 5 is a graph showing processing test results.

FIG. 6 is a graph showing the relationship between post-plating time and processing efficiency.

[Explanation of symbols]

 1 Tool 11 Base Material 12 Tire Mond Abrasive Grain 13 Nickel Plating Layer 32 Free Abrasive Grain

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B24D 3/06 B24D 3/06 B B28D 7/02 B28D 7/02

Claims (3)

[Claims] 1. A method of cutting or grooving a hard brittle material, wherein a fixed abrasive grain (12) is held by a plating layer (13) electrodeposited on the surface of a thin metal base material (11) and fixed in a straight blade shape. Using the abrasive grain tool (1), add a machining fluid that mixes free abrasive grains (32) with a diameter smaller than the protruding height (H) of the fixed abrasive grains from the plating layer (13) of the fixed abrasive grain tool to the machining part. A method for cutting or grooving a hard brittle material, characterized by performing processing while supplying. 2. The cutting or grooving of a hard brittle material according to claim 1, wherein the fixed abrasive grains (12) are diamond abrasive grains, and the plating layer (13) holding the fixed abrasive grains is a nickel plating layer. Processing method. 3. The method for cutting or grooving a hard brittle material according to claim 1, wherein the work is carried out while applying relative vibration in the cutting direction of the blade-shaped tool (1).