JPH03208563A - Inner peripheral type thin plate blade for cutting - Google Patents

Abstract

PURPOSE:To perform a highly accurate cutting slice work over a long time without a partial wear nor defect, by using the polycrystal film of a diamond formed by a vapor phase composition on a blade and forming the thickness of the whole body in 20 - 300mum. CONSTITUTION:The polycrystal film of a diamond formed by a vapor phase composition is used for an inner peripheral type thin plate blade for cutting and the thickness of the whole body is determined to 20 - 300mum. Consequently, the performances of a cutting accuracy, wear resistance, defect resistance, cost reduction, etc., can be improved, because of various binders, etc., being not included.

Description

[Detailed Description of the Invention] This invention relates to an inner circumferential thin plate blade used for cutting large-diameter ingots and a method for manufacturing the same, and is particularly useful for cutting single-crystal semiconductor ingots. This provides a blade with a wide range of features.

Conventional technology IC? using semiconductor materials such as Si, Ge, GaAs, InP, etc. When manufacturing an LSI, the cutting process of cutting a synthesized single crystal ingot into wafers is a very important process in determining the cost, quality, and yield of the product.

This cutting process cuts a round bar-shaped ingot with a thickness of 0.3 to 0.
．． It cuts into disc-shaped wafers of 5 μm, and uses a circumferential diamond grindstone, multi-wire, and multi-strip steel.

Conventionally, slicing using an internal grindstone has been most commonly used in terms of slicing efficiency, cutting cost, and cutting performance. Generally, the grinding wheel portion is made of diamond abrasive grains with a grain size of about 50 μm electrodeposited with nickel.

Problems to be Solved by the Invention As mentioned above, conventionally, diamond abrasive grains electrodeposited with nickel are used on the cutting edge, making it difficult to control the thickness of the cutting edge by electrodeposition. There were also problems in terms of accuracy and life, such as wear and falling off. Structure of the Invention The inventors of the present invention have studied in light of the above, and have developed a pure internal thin plate blade for cutting single-crystal semiconductor ingots. If a vapor-phase synthesized diamond film made only of diamond is used for cutting, cutting accuracy and
They discovered that it is possible to improve performance such as wear resistance, chipping resistance, and cost reduction, leading to the present invention.

That is, the present invention provides a thin inner peripheral thin plate blade for cutting, which is characterized by using a polycrystalline diamond film formed by vapor phase synthesis on the blade, and having a total thickness of 20 to 300 μm. This invention provides a new inner circumferential thin plate blade, and the cutting blade is particularly useful for cutting single crystal ingots.

In addition, in the cutting blade of the present invention, a concentric polycrystalline diamond plate formed by vapor phase synthesis is installed only at the cutting edge on the inner peripheral side of the blade, and the overall blade thickness is 20 to 300 μm. The present invention provides an inner peripheral type thin plate blade for cutting, which is characterized by the following.

Furthermore, the present invention provides a method for manufacturing the inner circumferential thin plate blade for cutting, in which a diamond film is formed on a base material by a vapor phase synthesis method, and the base material of the diamond film is dissolved and removed to form a single diamond. The present invention proposes a new method for manufacturing an inner circumferential thin plate blade for cutting, which comprises the steps of obtaining a diamond membrane and installing the single diamond membrane on the inner circumferential side of a concentric base metal blade.

Tomomine carp Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a schematic diagram of a conventional inner circumferential cutting blade, and Fig. 2 is an external view thereof, where l is a base metal, and 2 is a cutting edge with diamond abrasive grains 4 and a nickel electrodeposited layer 5 on the cutting edge. Department.

Figure 2 is an enlarged cross-section of the cutting edge in Figure 1.
As described in the prior art, problems include missing abrasive grains, wear of the electrodeposited layer, non-uniformity of film thickness, etc.

FIG. 3 is a schematic diagram of an inner peripheral cutting blade as a first embodiment of the present invention, in which a concentric vapor-phase synthetic diamond film 4 is installed on the inner peripheral side of a concentric base metal 3. be.

FIG. 4 is an enlarged cross-section of the cutting edge portion provided with the diamond film 4 shown in FIG.

FIG. 5 is a schematic diagram of an inner circumferential cutting blade 5 as a second embodiment of the present invention, in which the entire cutting blade is made of diamond formed by vapor phase synthesis.

FIG. 6 is an enlarged cross-section of the cutting edge of the diamond shown in FIG.

In order to increase the rigidity of an internal diamond grinding wheel, tensile stress is applied from the outer periphery of the base metal to tension it, but the tensile stress per unit volume is different between the inner and outer periphery, and a large tensile stress is applied to the inner periphery. . For this reason, waviness is likely to occur, and the process-affected layer of the wafer becomes large. In order to reduce this waviness, it is necessary to strongly tension the grindstone section.

The internal cutting blade using a vapor-phase synthetic diamond film as in this invention has a high tensile strength limit because the entire internal cutting blade is made of a diamond film formed by vapor-phase synthesis. , can be stretched more strongly,
This makes it possible to improve the cutting accuracy of wafers and to perform slicing for a long time.

In other words, by using a diamond film formed by vapor phase synthesis on an inner circumferential cutting blade, the cutting blade has the following characteristics compared to a conventional cutting blade in which a diamond abrasive grain-nickel electrodeposition layer is formed. That is, (1) since the outer circumferential portion can be stretched more strongly, the waviness on the inner circumferential side is reduced and the cutting precision of the wafer is improved.

■Since it does not contain a binder (IL adhering layer), there is less wear and long slining work is possible. For this reason,
It becomes possible to reduce the number of times of relining, and it is possible to achieve a significant cost reduction.

■If the base material of the diamond formed on the base material is to be the cutting edge side of the diamond on the base material side that has been dissolved and removed,
It is possible to achieve a cutting edge with a surface roughness of RMAX: approximately 0.05 μm. For this reason, it is possible to significantly improve the finished state of the workpiece after cutting, and it is possible to cut to the final finished state at once without going through the conventional multiple steps of rough finishing and precision finishing. It is also possible to reduce marks and improve cutting accuracy.

■Can handle large-diameter internal blades with high precision.

■Since there is no loss of abrasive grains, it has excellent wear resistance and durability.

(2) The diamond particle size can be freely controlled by changing the vapor phase synthesis conditions, and a diamond film with a thickness of several 10 μm can be formed. Therefore, the number of cuts can be reduced and cutting accuracy can be improved.

■It is possible to increase the thickness of the inner periphery of the cutting edge and reduce the particle size toward the outer periphery by controlling only the diamond film synthesis conditions, improving quality and yield.

The thin plate blade for cutting a single crystal of the present invention is characterized in that a diamond film is formed by vapor phase synthesis, and the total thickness is 20 μm or more and 300 μm or less.

In addition, the thin plate blade for cutting ingots of the present invention has a diamond film formed by vapor phase synthesis on at least the inner peripheral side of the base metal, that is, the cutting edge side, and has a total thickness of 20 μm.
It is characterized in that it is not less than m and not more than 300 μm.

This is because if the total thickness is less than 20 μm, the strength of the base metal and the diamond itself will be insufficient and it will easily break.
This is because if the cutting distance is more than μm, the cutting allowance becomes large, leading to a decrease in the retention.

FIGS. 10 and 11 show schematic diagrams of the manufacturing process of an inner circumferential blade for cutting using diamond formed only at the cutting edge by vapor phase synthesis according to the present invention.

The manufacturing process shown in FIGS. 10 and 11 basically consists of: (i) forming the diamond 4 on the base material 6 by vapor phase synthesis; 11
The figure shows a case where a concentric base material is used. ), 2) A process of dissolving and removing the diamond-coated base material 6 of the diamond-coated base material produced in the step l) above by acid treatment etc. to obtain a single diamond film, 3) A process of fixing the single diamond film 4 to the base metal 3 , consists of.

As a base material for diamond formation, a cylindrical base material 6 is used as shown in FIG. 10 (1). A diamond film 4 is formed on the side surface of 6. In FIG. 7, 9 is the main body of the apparatus, IO is a cooling support for the base material 1, 11 is a filament, 12 is an electrode, 13 is an inlet for gas, etc., 14 is a cooling water inlet/outlet, and 15 is an exhaust port.

Further, using the concentric cylindrical base material 6 shown in FIG. 11(1), the inner periphery of the concentric cylindrical base material 3 is formed by a filament CVD apparatus using, for example, a diamond synthesis apparatus shown in FIG. A diamond film 4 is formed on the side surfaces.

Next, as shown in Figure 10 (2) or Figure 11 (2),
Then, the base material 6 is dissolved and removed by, for example, acid treatment to form a concentric diamond single film 4.

After this, as shown in FIG. 10 (3) or FIG.
Glue and fix to the inner circumferential side.

In this case, the thickness of the side surface of the cylindrical base material 6 for diamond coating is made larger than the desired width A of the diamond film, and after the diamond film is coated, the material is cut to the desired thickness A width using a laser or the like. It is also possible to use The base material 6 to be used may be a regular base material for diamond formation, but for example, MoS
w, S i-, T aSN b- Cu, A I
1B 1B eN A us P t- P esTi
, C%Si deposited, SiC. AIN, SiN,
WC, MoC, BN, BC, NbC, TaC
etc. are possible.

The material of the base metal is usually SK material, stainless steel material, etc. Although it is possible to fix the diamond 4 and the base metal 3 using an adhesive or the like, it is preferable to use brazing from the viewpoint of heat resistance and durability.

There are two methods for producing concentric diamond single-layer films, as shown in Figure 1O and Figure 11. In the case of Figure 10, when diamond is deposited on the base material, the base material surface side is the cutting edge, The uneven growth surface side will be the adhesive surface. In this case, by improving the surface treatment roughness of the side surface of the base material, it is possible to improve the surface roughness of the diamond at the cutting edge. Therefore, it is possible to improve the surface roughness of the work material after cutting, and it can also be used for finishing purposes.

On the other hand, in the case of Fig. II, the structure of the cutting edge portion and the bonding portion is exactly opposite to that of Fig. 1O, and the surface roughness of the workpiece is somewhat deteriorated, so it is useful for rough finishing.

The process for manufacturing the entire inner circumferential cutting blade using vapor-phase synthetic diamond is similar to the process for the adhesive type described above. As an example of an apparatus for diamond synthesis in this case, FIG. 9 shows a schematic diagram of a filament CVD apparatus.

As mentioned above, FIGS. 7, 8, and 9 show an example of a diamond coating CVD apparatus used to form a vapor-phase synthetic diamond film on a substrate in an embodiment of the present invention. FIG. 2 is a cross-sectional view of a filament CVD apparatus. These devices are designed to operate under vacuum. In addition, in the case of such an apparatus, several to several tens of filaments 11, which are gas activation sources, are installed, and the substrate cooling support stand 10 may be rotated.

Further, the symbol D in the figure is the distance between the filament and the diamond coating substrate.

(Experiment example l) An experimental example in which this invention was actually implemented is shown below.

Using the apparatus shown in Fig. 7, the diamond coating base material 6
A cylindrical disk having an outer diameter of 1840 mm+ as shown in Table 1 was prepared.

Then, under the synthesis conditions shown in Table 1, a diamond film 4 was deposited on the cylindrical side surface of the round board base material 6. After this, Figure IO (
A single diamond film was obtained according to the manufacturing steps shown in 1) and (2), and the precipitation state was observed in parts (A) and (B) of FIG. 10 (1), and the results shown in Table 2 were obtained.

In addition, the comparative example in Table 2 is Ni
An electrodeposited layer is formed.

(Left below) Table 2 Using the inner circumferential blade thus obtained, the blade circumferential speed 1
0 0 0 m/win, machining feed speed 4 0 am/
Diameter 1800mm under IIlin slicing conditions
A processing and slicing test was conducted on silicon single crystal ingots. The results are shown in Table 3.

In a comparative example, a similar test was conducted using an inner peripheral type blade in which a Ni electrodeposited portion was formed on the cutting edge according to the prior art shown in FIG.

(The following is a blank space) From Table 3 above, it is recognized that the inner circumferential thin plate cutting blade of the present invention, in which a vapor-phase synthetic diamond film is formed on the cutting edge, greatly improves cutting accuracy and service life. It was done.

(Experiment Example 2) Diamond coating filament CV shown in Fig. 9
Using the D device, the diamond coating base material 6 was made of polycrystalline Si material with an inner diameter of 840 mm as shown in FIG. 11 (1).
, an outer diameter of 4930 mm and a thickness of 0.1 mm to deposit diamond. When the same slicing test as in Experimental Example 1 was conducted using the single diamond blade 5 after the base material 6 had been melted and removed, 2,000 pieces could be sliced in Experimental Example 2.

As explained above, the thin plate blade for cutting single crystals of this invention has a diamond film formed by vapor phase synthesis on the cutting edge, and there is no binder such as Ni or Go or an electrodeposited layer as in the past. Therefore, there is no local wear or damage, and high-precision cutting and slicing work can be performed for a long time. For this reason, it reduces the work required to replace the blade, improves the retention of the blade, and greatly contributes to cost reduction.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional internal circumferential cutting blade;
The figure shows an enlarged cross-sectional view of the cutting edge of a conventional internal cutting blade.
FIG. 3 is a schematic diagram of an internal cutting blade using vapor-phase synthetic diamond only at the cutting edge according to the present invention, FIG. 4 is an enlarged sectional view of the cutting edge of the cutting blade according to the present invention in FIG. 3, and FIG. 5 6 is a schematic diagram of an inner peripheral cutting blade according to the present invention in which the entire cutting blade is made of vapor-phase synthetic diamond; FIG. 6 is an enlarged cross-sectional view of the cutting edge of the cutting blade of the present invention shown in FIG. 5; FIG.
FIGS. 8 and 9 are explanatory diagrams of a filament CVD apparatus which is an example of diamond cost equipment used in the present invention. Figure 10 (1). (2), (3) and Figure 11 (
1). (2) and (3) are schematic diagrams showing two embodiments of the manufacturing process of the cutting blade of the present invention. 3... Base metal, 4... Vapor phase synthetic diamond film,
6...Base material, 10...Cooling support stand, II...
・Filament, l2...electrode.

Claims (1)

[Claims] 1. A cutting blade characterized in that the blade uses a polycrystalline diamond film formed by vapor phase synthesis, and has a total thickness of 20 to 300 μm. Circumferential thin plate blade. 2. The inner peripheral thin plate blade for cutting according to claim 1, wherein the cutting blade is for cutting a single crystal ingot. (Product patent: Type using vapor-phase synthetic diamond only at the cutting edge) 3. In the cutting blade, a concentric polycrystalline diamond plate formed by vapor-phase synthesis is installed only at the cutting edge on the inner peripheral side of the blade. and the overall blade thickness is 2.
An inner circumferential thin plate blade for cutting, characterized in that the diameter is 0 to 300 μm. 4. The inner peripheral type thin plate cutting blade according to claim 3, wherein the diamond is installed on the cutting blade by brazing. 5. The inner peripheral thin plate blade for cutting according to claim 3 or 4, wherein the cutting blade is for cutting a single crystal ingot. 6. Form a diamond film on a base material by vapor phase synthesis, dissolve and remove the base material of the diamond film to obtain a single diamond film, and apply the single diamond film to the inner periphery of a concentric base metal blade. A method for manufacturing an inner peripheral type thin plate blade for cutting, characterized in that it is installed on the side. 7. The method of manufacturing an inner circumferential thin plate blade for cutting according to claim 6, wherein the vapor-phase synthesized single diamond film and the base metal blade are installed by brazing.