JPH0829497B2 - Inner edge diamond whetstone - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a new inner peripheral edge diamond grindstone, and more specifically, to suppress the attachment of cutting chips and reduce warpage, chipping, work-affected layer, etc. of a workpiece such as a wafer. In addition, the present invention relates to a long-life inner-diameter diamond grindstone that does not require a lubricant such as molybdenum disulfide, which is necessary for the outer peripheral portion of the grindstone when the inner-diameter diamond grindstone is mounted on a machine.

[0002]

2. Description of the Related Art Generally, an inner peripheral edge diamond grindstone is often used for slicing silicon, gallium arsenide, ceramics or quartz to make a wafer. Conventionally, as shown in FIG.
And the one shown in FIG. 2 is commonly used. FIG.
2 and FIG. 2 are respectively a plan view and a cross-sectional view of an example of an inner peripheral edge diamond grindstone that has been generally used conventionally,
A diamond abrasive grain having a grain size of about 40 to 60 μm is fixed to the inner periphery of the hole 2 formed in the central portion of the base metal 1 and its vicinity by nickel plating to form the abrasive grain layer 3. There is. However, in such a conventional inner peripheral edge diamond grindstone, when the silicon or the like is cut, chips are attached to the base metal and the base metal is scratched, resulting in fatigue of the base metal. For this reason, the constant tension (tensile stress) applied to the base metal is relaxed, the cutting blade is loosened and a constant cutting trajectory cannot be drawn, and vibration starts up and down. Due to this, there is a problem that warpage of a processed product such as a wafer, an increase in a process-affected layer, defective thickness accuracy, chipping, and chipping occur. Further, when installing the inner peripheral edge diamond grindstone on the machine, a lubricant such as molybdenum disulfide is required for several cm of the outer peripheral part of the grindstone. The grindstone becomes complicated to install, and it also results in soiling the work piece. Furthermore, the base metal may be damaged when cutting silicon, etc., which may reduce the strength of the base metal and lead to a life out of the base metal. There was also a problem that the sharpness was deteriorated due to the falling of the grains.

[0003]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of such a conventional inner peripheral edge diamond grindstone,
Prevents chips from adhering and prevents damage to the base metal,
In addition to reducing warpage, chipping, and work-affected layers of workpieces such as wafers and improving the thickness accuracy of workpieces, lubricants such as molybdenum disulfide are not required on both sides of the base metal of the grindstone outer peripheral clamp part, Moreover, the purpose of the present invention is to provide an inner peripheral edge diamond grindstone that has a long life and little scratches or wear of the base metal or the plating layer to which the abrasive grains are fixed.

[0004]

Means for Solving the Problems As a result of intensive studies to develop an inner peripheral edge diamond grinding stone having the above-mentioned preferable properties, the present inventors have found that the inner periphery of a ring plate-shaped base metal and the vicinity thereof. In the inner edge grindstone in which diamond abrasive grains are fixed by nickel plating, etc., the purpose is achieved by coating the entire front and back surfaces of the base metal and the portion where the abrasive grains are fixed with a diamond-like carbon film. Therefore, the present invention has been completed based on this finding. That is, the present invention has a thickness of 0.5 to 10 on the substrate.
The present invention provides an inner peripheral edge diamond grindstone formed by coating a diamond-like carbon film having a thickness of μm. Hereinafter, the present invention will be described in detail. The diamond grindstone of the present invention is a conventionally known inner peripheral edge grindstone, that is, an inner peripheral edge diamond grindstone in which diamond abrasive grains are fixed by nickel plating or the like on the inner periphery of a ring plate-shaped base metal made of stainless steel or the like. In the above, the entire front and back surfaces except for the outer peripheral portion of the base metal by several cm and the portion to which the abrasive grains are fixed are coated with a diamond-like carbon film.

The diamond-like carbon film has a thickness of 0.
It is preferably in the range of 5 to 10 μm. If this film thickness is less than 0.5 μm, pinholes are likely to occur during film formation, and the film wears quickly, resulting in poor reliability. On the other hand, if the film thickness exceeds 10 μm, the film tends to peel off from the substrate due to internal stress of the film itself, and sufficient adhesion cannot be obtained. In the inner peripheral edge diamond grindstone of the present invention, the method for forming the diamond-like carbon film on the substrate is not particularly limited, and a conventionally known method, for example, a chemical vapor deposition method (CVD) is preferably used.

In this CVD method, the source gas is activated by, for example, (1) applying a high frequency to the introduction portion of the source gas and forming plasma by the high frequency by means of guiding the source gas to an activated state. High-frequency plasma CVD method for introducing a state, (2) microwave plasma CVD method using microwaves instead of the high-frequency wave, (3)
A direct current plasma CVD method of applying a direct current to form plasma, (4) an ion beam CVD method of bringing a source gas into an activated state by an ion beam, and the like can be used. In this CVD method, a mixed gas composed of a carbon source gas and hydrogen used as needed and an inert gas such as argon as a carrier gas is used.
Examples of the carbon source gas include carbon monoxide, carbon dioxide, alkanes, alkenes, alkynes, aromatic hydrocarbons, cycloparaffins, cycloolefins, oxygen-containing carbon compounds and nitrogen-containing carbon compounds. One kind or a mixture of two or more kinds selected from is used.

FIG. 3 is a schematic view showing an example of an apparatus for forming a diamond-like carbon film on a substrate by the CVD method. To carry out the CVD method, first, two reactors in a reaction vessel are used. An inner peripheral grinding wheel (also serving as a cathode) 6 is installed between the anode plates 5 and 7, and the inside of the reactor is evacuated by a vacuum pump connected to the exhaust port 8. A carbon source gas and a mixed gas composed of hydrogen and an inert gas used as needed were introduced from an inlet 4, and the pressure in the reactor was adjusted to 5 by a vacuum pump connected to an outlet 8.
The voltage is adjusted to about 0 to 100 mTorr, and then a voltage of about 750 to 1000 V is applied between the anode plates 5 and 7 and the inner peripheral edge grinding wheel (which becomes the cathode) 6 via the current introduction terminal 10 by the DC power supply 9. To generate plasma. In this way, the carbon source gas is decomposed into a diamond-like carbon film, which is simultaneously formed on the front and back surfaces with a desired thickness on the substrate. 4 and 5 are a plan view and a cross-sectional view of an example of an inner peripheral edge diamond grindstone of the present invention, showing the inner periphery of a ring plate-shaped base metal 1 having an opening 2 in the center and the vicinity thereof. It has a diamond abrasive grain layer 3 and the number of outer peripheral parts of the base metal 1 is several.
A structure in which the diamond-like carbon film 11 is coated on the entire front and back surfaces excluding cm and the abrasive grain layer 3 portion is shown.

[0008]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Example 1 As a base, an Asahi Diamond Industrial Co., Ltd. inner diameter diamond grindstone (outer diameter 690 mm, inner diameter 240 mm, plate thickness 150)
μm, blade thickness 300 μm, blade width 3 mm, abrasive grain size 40-60 μm
m) was used to coat a diamond-like carbon film on the entire surface excluding a few cm of the outer peripheral portions on both the front and back sides by the CVD method shown below. That is, the inner peripheral edge diamond grindstone is first placed in the center of both anode plates as shown in FIG. Next, after the inside of the reaction vessel was evacuated, methane gas was introduced, the pressure in the reactor was kept at 100 mTorr, the voltage between the electrode plates was kept at 1000 V, plasma was generated, and a diamond-like carbon film was formed for 80 minutes. In this way, about 1μ on both sides
An inner peripheral edge diamond grindstone having a diamond-like carbon film layer of m was obtained. As a result of Raman spectroscopic analysis of the film obtained at this time, it was confirmed that the film was a diamond-like carbon film having a broad peak at 1550 cm ^-1 . Using this inner edge diamond grindstone, a 6-inch silicon ingot is fed at a feed rate of 60 mm / min, a peripheral speed of 1100 m / min,
It was cut under the condition of the coolant pure water. As a result, the adhesion of cutting chips to the base metal when cutting silicon was reduced. Further, due to this fact and the lubricity of the diamond-like carbon film itself, the cutting resistance was lowered. Furthermore, due to the protective effect of the high-hardness diamond-like carbon film, the scratches on the base metal and the wear of the nickel layer to which the abrasive grains are fixed are also greatly reduced. As a result of these, the life of the inner peripheral edge diamond grinding wheel was improved.

[0009]

According to the present invention, due to the water repellency of the DLC film, there is almost no water splash of the coolant and the adhesion of cutting chips is suppressed. As a result, scratches and metal fatigue on the base metal are reduced, and the tension of the base metal is kept low.
Therefore, the cutting blade draws a constant trajectory without swinging up and down, and from these things, the warpage of the workpiece such as wafer,
In addition to reducing the work-affected layer and improving the thickness viscosity of the work piece, when installing the grindstone on the machine, a lubricant such as molybdenum disulfide is not required on the outer periphery of the grindstone, and the base metal and the grindstone are used. It is possible to obtain an inner cutting edge diamond grindstone with a long life and less scratches and wear of the plating layer that fixes the grains.

[Brief description of drawings]

FIG. 1 is a plan view of an example of a conventional inner peripheral edge diamond grindstone.

FIG. 2 is a cross-sectional view of an example of a conventional inner peripheral edge diamond grindstone.

FIG. 3 is a schematic view of an example of a chemical vapor deposition apparatus for producing an inner peripheral edge diamond grinding stone of the present invention.

FIG. 4 is a diagram of an inner peripheral edge diamond grindstone of the present invention.
It is a top view of an example.

FIG. 5 is a diagram of an inner peripheral edge diamond grindstone of the present invention.
It is sectional drawing of an example.

[Explanation of symbols]

 1 base metal 2 opening part 3 diamond abrasive grain layer 4 reaction gas introduction port 5 anode plate 6 inner peripheral edge grindstone 7 anode plate 8 exhaust port 9 DC power supply 10 current introduction terminal 11 diamond-like carbon film

Claims (1)

[Claims] 1. An inner peripheral edge diamond grindstone comprising a substrate coated with a diamond-like carbon film having a thickness of 0.5 to 10 μm.