JP4787615B2 - Super-abrasive whetstone with shaft and method for manufacturing the same - Google Patents

Description

The present invention relates to a shaft-equipped superabrasive grindstone and a method for producing the same. The present invention can be suitably applied particularly to a superabrasive grindstone with a shaft used for notching or the like of a silicon wafer.

With the recent technological development of the semiconductor industry, the diameter of silicon wafers has increased, the integration density of IC chips and the wiring density have increased, and thereby the importance of positioning accuracy has increased. There is also a demand for improvement in semiconductor manufacturing efficiency, such as obtaining as many IC chips as possible from a single silicon wafer. Conventionally, silicon wafers have been provided with a portion called an oriental flat, which is obtained by positioning a portion of the circular shape linearly for positioning during silicon wafer processing, but from the viewpoint of positioning accuracy and semiconductor manufacturing efficiency, As shown in FIG. 1, a method of providing a small notch called a notch (12) in a part of a wafer (11) is often used. The notch is formed using a superabrasive grindstone with a shaft corresponding to the size.

In FIG. 2, the schematic diagram of a superabrasive grindstone with a shaft is shown. The shaft-equipped superabrasive grindstone (13) is a grindstone with a shaft in which a superabrasive grain layer (grindstone portion) (15) is fixed to one end of a shaft (shank portion) (14) as a general configuration. The other end of the shaft is held by a chuck of a grinding machine, and rotated about the rotating shaft of the machine for grinding. The grindstone portion is provided with a groove (16) for processing the object to be ground.

An example of a superabrasive grindstone with a shaft is a superabrasive grindstone with a shaft in which a superabrasive grindstone portion and a shank portion are joined to each other via a small-diameter rod in Patent Document 1, and one end of the small-diameter rod is a shank portion. Is inserted and fixed in an axial insertion hole provided on the other end, and the other end side is fixed to a superabrasive grindstone. Further, in Patent Document 2, a superabrasive grain layer is a superabrasive grindstone with a shaft fixed to a shaft center portion integrally provided with a shaft (shank portion), and the shaft center portion is formed in a tapered shape. Is disclosed.
JP 2003-25234 A JP-A-2005-14163

From the viewpoint of improving the processing productivity of silicon wafer notches, the improvement of sharpness and the extension of the service life of shaft-type superabrasive grinding wheels are becoming more important than ever.
Further, it is required to form a large number of machining grooves in the grindstone portion so that a large number of machining can be performed with a single superabrasive grindstone with a shaft, and to increase the height of the grindstone portion.

This superabrasive grindstone with a shaft is generally manufactured by hot pressing. Specifically, by placing a grindstone material mixture on the axially upper part of a pre-molded shank, and hot-pressing (hot compressing) the mixture downward in the axial direction with a pressing die, a desired grindstone is used in the grindstone. Density is achieved and the grindstone portion and the shank portion are joined.

On the other hand, as the material of the shank part, generally raw material without baking is used. Since the raw material is low in hardness and soft, finishing after hot pressing is easy, but there is a problem that the shank part is deformed into a drum shape due to high pressing during hot pressing. Further, when the pressing mold is made of raw material, there is a problem that the pressing mold is similarly deformed into a drum shape.

FIG. 3 schematically shows one embodiment of manufacturing a conventional superabrasive grindstone with a shaft. In FIG. 3, the shaft-equipped superabrasive grindstone (21) has a configuration in which the grindstone portion (23) is formed at one end of the shank portion (22). The superabrasive grindstone with a shaft (21) is manufactured by the following procedure. That is, the shank part (22) molded using raw materials in advance is placed in the mold band (24), and the grindstone part material mixture (23) containing superabrasive grains is placed in the upper part of the shank part (22) in the axial direction. To do. Subsequently, this mixture (23) is hot-pressed (hot compression) downward in the axial direction by an upper pressing mold (25) made of raw material. During this hot pressing, stress is applied in the axial direction of the upper pressing mold (25) as the pressing (molding pressure) increases, and in particular, the shank portion (22) and the upper pressing formed from raw materials with low hardness. Stress concentrates at the boundary between the mold (25) and the mold band (24), and as a result, a drum-shaped deformation (26, 27) is formed. When such deformation occurs, the shank part (22) and the upper pressing mold (25) will not fit in the mold band (24), and the force due to pressing will not be transmitted to the grinding wheel part (23), resulting in the grinding stone part ( In 23), a desired density cannot be obtained, and the grindstone becomes softer than the design.

The shank portion needs to have high hardness that does not deform into a drum shape during hot pressing as described above. On the other hand, since the finishing process is usually performed together with the superabrasive grindstone layer after hot pressing, the hardness is too high so that the finishing process does not take time and effort. desirable.

As a result of diligent research in view of the above-described problems of the prior art, the present inventors are a shaft-equipped superabrasive grindstone in which a grindstone portion using superabrasive grains as an abrasive material is formed at one end of the shank portion, the shank portion Is made of a metal material that has been quenched or quenched and tempered, and the metal material of the shank is selected from the group consisting of high-speed steel, hot die steel, stainless steel, and heat-resistant steel, and nickel strike treatment on the shank Copper plating is applied later, the grindstone part is composed of superabrasive abrasives bonded with a metal bond binder, and the hardness of the shank part after grinding of the grindstone part is 35 to 20 on the HRC scale. The present inventors have found that the deformation of the shank part and the upper pressing mold can be avoided and that the workability after hot pressing can be secured in the shank part.

That is, the present invention is a shaft-equipped superabrasive grindstone in which a grindstone portion using superabrasive grains as an abrasive material is formed at one end of the shank portion, and the shank portion is quenched or quenched / tempered. It is comprised from these, It is characterized by the above-mentioned.

In the shaft-equipped superabrasive grindstone of the present invention, the metal material of the shank portion is preferably selected from the group consisting of high speed steel, hot die steel, stainless steel and heat resistant steel. Moreover, it is preferable that copper plating is performed after nickel strike processing to the shank part, and the hardness of the shank part after grinding of the grindstone part is preferably 35 to 20 on the HRC scale. Furthermore, it is preferable that the grindstone portion is formed by bonding superabrasive abrasives with a metal bond binder.

The present invention is also a method for producing a shaft-equipped superabrasive grindstone, wherein a shank portion is formed from a metal material that has been quenched or quenched and tempered, and the metal material of the shank portion is made of high-speed steel, hot Select from the group consisting of die steel, stainless steel and heat-resistant steel, further copper plating after nickel strike treatment to the shank part, the grindstone part is constituted by bonding superabrasive abrasive with a metal bond binder, By a hot press method in which a grinding wheel part raw material including a superabrasive abrasive and a binding material is disposed on the axial upper part of the shank part, and the grinding wheel part raw material is pressed downward in the axial direction of the shank part by an upper pressing die, Joining the grinding wheel part and the shank part, the hardness of the shank part before grinding of the grinding wheel layer is 45 or more on the HRC scale, and the hardness of the shank part after grinding of the grinding wheel part is 35 to 20 on the HRC scale. ,That , Characterized in that the upper pressing mold is be constructed from a metal material subjected to back quenching or quenching and tempering.

In the method for manufacturing a shaft-equipped superabrasive grindstone of the present invention, the metal material of the upper pressing die is preferably selected from the group consisting of high speed steel, hot die steel, stainless steel, and heat resistant steel.

According to the present invention, a superabrasive grindstone with a shaft having a desired density is provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the superabrasive grindstone with a shaft of the present invention and the manufacturing method thereof will be described.
First, a preferred embodiment of the superabrasive grindstone with a shaft of the present invention will be described.
The superabrasive grindstone with a shaft of the present invention is a superabrasive grindstone with a shaft in which a grindstone portion using superabrasive grains as an abrasive material is formed at one end of the shank portion, and the shank portion is quenched or quenched / tempered. It is comprised from the metal material which gave.

FIG. 4 schematically shows one embodiment of the production of the shaft-equipped superabrasive grindstone of the present invention.
In FIG. 4, a superabrasive grindstone with a shaft (101) has a configuration in which a grindstone portion (103) is formed at one end of a shank portion (102).

In the present invention, the abrasive of the grindstone is assumed to be superabrasive grains. The superabrasive grains are selected from CBN abrasive grains and diamond abrasive grains. It is preferable to use diamond abrasive grains for notching a silicon wafer.

A resin bond, a metal bond, or a composite bond thereof can be used as the binding material for the grindstone. In general, it is preferable to use a metal bond.
In this invention, a shank part shall be comprised from the metal material which gave quenching or quenching and tempering.

The hardness of the shank portion decreases as the temperature rises during hot pressing. The degree of hardness reduction varies depending on the material of the shank part, the quenching temperature, the tempering temperature, the sintering temperature at the time of hot pressing, the sintering time, and the like. If the metal material used for the shank part is hardened and its hardness is improved, even if it is hot pressed for joining with the grindstone part, its hardness will not decrease excessively. Maintains a higher hardness than raw materials. As a result, the shank portion does not deform into a drum shape due to the molding pressure during hot pressing as seen in the prior art.

The shank portion needs to have high hardness that does not deform into a drum shape during hot pressing as described above. On the other hand, since the finishing process is usually performed together with the superabrasive grindstone layer after hot pressing, the hardness is too high so that the finishing process does not take time and effort. desirable. Therefore, the hardness of the shank portion is preferably HRC45 or more before grinding of the grinding wheel layer, and preferably HRC35 to 20 after grinding of the grinding stone layer.

The metal material of the shank portion is preferably selected from the group consisting of high speed steel, hot die steel, stainless steel and heat resistant steel, but materials other than those exemplified are also used without departing from the spirit of the present invention. be able to.

Moreover, it is preferable that the shank part has been subjected to nickel strike treatment and copper plating. Thereby, the adhesiveness of a shank part and the grindstone part containing a superabrasive grain is securable.

In another aspect of the present invention, a shaft-equipped superabrasive grindstone has a shank portion and a grindstone portion joined via a small-diameter rod, and one end of the small-diameter rod is inserted into an axial insertion hole provided in the shank portion. The other end may be fixed to the grindstone portion. The small-diameter bar has a diameter smaller than that of the shank portion and the grindstone portion. By having such a structure of the superabrasive grindstone with a shaft, there is an advantage that the strength against the force from the lateral direction with respect to the shaft can be secured and the bending can be strengthened.

In FIG. 5, another aspect of manufacture of the superabrasive grindstone with a shaft of this invention is shown roughly.
In FIG. 5, a shaft-equipped superabrasive grindstone (111) has a shank portion (112) and a grindstone portion (113) joined via a small diameter rod (116), and one end of the small diameter rod (116) is the shank portion. (112) It is inserted and fixed in the axial insertion hole provided in (112), and it has the structure by which the other end of this small diameter rod (116) was axially stopped by this grindstone part (113). Such a configuration is the same as that described in Japanese Patent Laid-Open No. 2003-25234 (Patent Document 1).

The presence of the small-diameter bar (116) at the shaft center of the superabrasive grindstone with a shaft (111) helps to prevent the grindstone from being bent with respect to the side pressure in use conditions in which side pressure is often applied in notching. . Like the shank portion (112), the small-diameter bar (116) is preferably made of a metal material that has been quenched or quenched and tempered. Specifically, high-speed steel, hot die steel, stainless steel It is preferably composed of a metal material selected from the group consisting of steel and heat resistant steel. Further, materials other than those exemplified can be used without departing from the gist of the present invention. It is not always necessary to use the same material as the shank part.

In still another aspect of the present invention, the shaft-equipped superabrasive grindstone may be formed in a tapered shape at one end where the shank portion is in contact with the grindstone portion.
FIG. 6 schematically shows still another aspect of the production of the shaft-equipped superabrasive grindstone of the present invention.

In FIG. 6, the shaft-equipped superabrasive grindstone (121) has a grindstone portion (123) formed at one end of the shank portion (122), and the shank portion (122) tapers at one end in contact with the grindstone portion (123). It has a formed configuration. By processing the shank portion (122) into a taper shape, it is possible to ensure a strong fixing force between the shank portion (122) and the superabrasive grindstone portion (123).

Moreover, the shank part (122) can ensure sufficient adhesiveness with a superabrasive grindstone part, without performing a taper-shaped process.
Next, the suitable embodiment of the manufacturing method of the superabrasive grindstone with a shaft of the present invention is described. Hereinafter, about the manufacturing method of a superabrasive grindstone with a shaft, the description which overlaps with the above-mentioned superabrasive grindstone with a shaft is abbreviate | omitted.

The method for producing a shaft-equipped superabrasive grindstone of the present invention includes forming a shank portion from a metal material that has been quenched or quenched and tempered, and applying copper plating after nickel strike treatment to the shank portion, A grindstone part raw material including a superabrasive abrasive and a binding material is disposed at an upper part in the direction, and the grindstone part and the grindstone part are formed by a hot pressing method in which the grindstone part raw material is pressed downward in the axial direction of the shank part by an upper pressing mold. Including joining the shank portion, wherein the upper pressing die is made of a metal material that has been quenched or quenched and tempered.

In the present invention, by forming a shank portion from a metal material subjected to quenching or quenching / tempering, high pressure is applied during hot pressing, and the shank portion is deformed into a drum shape, and a grindstone portion containing superabrasive grains It is possible to overcome the problem of the prior art that the desired density cannot be obtained. The conditions (quenching temperature, tempering temperature, time, etc.) for quenching or quenching / tempering of the metal material of the shank part are that the desired hardness is obtained in the shank part after quenching or quenching / tempering. It can be determined as appropriate depending on the material of the metal material, the sintering temperature during hot pressing, the sintering time, and the like. The hardness of the shank part is preferably HRC45 or more before grinding the grinding wheel layer, and preferably HRC35 to 20 after grinding the grinding wheel layer.

Similarly, by using an upper pressing mold made of a metal material that has been quenched or quenched / tempered during hot pressing, the molding pressure during hot pressing as seen in the prior art. Therefore, the upper pressing mold is not deformed into a drum shape. Conditions for quenching or quenching / tempering of the upper pressing mold (quenching temperature, tempering temperature, time, etc.) depend on the material, sintering temperature at the time of hot pressing, sintering time, etc. Can be determined.

In this invention, the adhesiveness of a shank part and the grindstone part containing a superabrasive grain is securable by giving a copper plating after nickel strike processing to a shank part.
The metal material used for the upper pressing mold does not need to be subjected to nickel strike treatment or copper plating. In the first place, it is not necessary to join the superabrasive grindstone part, but rather it is desirable that it can be easily released after hot pressing.

In the method of manufacturing a superabrasive grindstone with a shaft of the present invention, the metal material of the upper pressing mold is a group consisting of quenching or quenching / tempering high speed steel, hot die steel, stainless steel, and heat resistant steel. Although preferably selected, materials other than those exemplified may be used without departing from the spirit of the present invention. It is not always necessary to use the same material as the shank part.

FIG. 4 schematically shows one embodiment of the production of the shaft-equipped superabrasive grindstone of the present invention.
In FIG. 4, a superabrasive grindstone with a shaft (101) has a configuration in which a grindstone portion (103) is formed at one end of a shank portion (102). The superabrasive grindstone with a shaft (101) is manufactured by the following procedure. That is, the shank portion (102) is formed from a metal material that has been quenched or quenched and tempered, and is disposed on the mold band (104). Next, after the nickel strike treatment, copper plating is performed on the upper portion in the axial direction of the shank portion (102), and a grindstone material mixture (103) containing superabrasive grains is disposed. Subsequently, this mixture (103) is hot-pressed (hot compression) downward in the axial direction by an upper pressing die (105) made of a heat-treated metal material. During this hot pressing, stress is applied in the axial direction of the upper pressing mold (105) as the pressing (molding pressure) increases, and in particular, the shank portion (102), the upper pressing mold (105) and the mold band (104). However, in the present invention, both the shank part (102) and the upper pressing mold (105) are harder than the conventional technique, so that a drum-shaped deformation occurs. There is nothing. Therefore, further pressurization is possible, and the shank part (102) and the upper pressing mold (105) are inserted into the mold band (104) as intended, and the pressing force is transmitted to the grindstone part (103). The After hot pressing, a superabrasive grindstone portion having a desired density is formed, and the disadvantage of the prior art that the life of the grindstone during grinding is reduced is eliminated.

Next, FIG. 5 schematically shows another aspect of the production of the shaft-equipped superabrasive grindstone of the present invention.
In FIG. 5, a shaft-equipped superabrasive grindstone (111) has a shank portion (112) and a grindstone portion (113) joined via a small diameter rod (116), and one end of the small diameter rod (116) is the shank portion. (112) It is inserted and fixed in the axial insertion hole provided in (112), and it has the structure by which the other end of this small diameter rod (116) was axially stopped by this grindstone part (113). The superabrasive grindstone with a shaft (111) is manufactured by the following procedure. That is, the shank portion (112) is formed from a metal material that has been quenched or quenched and tempered, and is disposed on the mold band (114). A small-diameter hole for the small-diameter rod (116) is provided at the shaft center of the shank portion (112), and a small amount of metal powder is put into the small-diameter hole to help the shank portion (112) and the small-diameter rod (116) to be fixed. Insert the small diameter rod (116). The metal powder should just have a melting | fusing point lower than a shank part metal material. Next, after the nickel strike treatment, copper plating is applied to the upper part of the shank part (112) in the axial direction, and a grindstone material mixture (113) containing superabrasive grains is placed thereon. Next, the mixture (113) is made of a metal material that has been quenched or quenched and tempered, and is axially moved by an upper pressing die (115) provided with a through hole for a small-diameter rod (116) in the center. Hot press downward (hot compression). Similar to the embodiment shown in FIG. 4, stress is concentrated at the boundary between the shank portion (112) and the upper pressing mold (115) and the mold band (114) during hot pressing. Both the shank portion (112) and the upper pressing die (115) are harder than the prior art, so that no drum-shaped deformation occurs. Therefore, further pressurization is possible, and the shank part (112) and the upper pressing mold (115) are inserted into the mold band (114) as intended, and the pressing force is transmitted to the grindstone part (113). The The small diameter rod (116) is fixed to the shank portion (112) by pressurization. After hot pressing, a superabrasive grindstone portion having a desired density is formed, and the disadvantage of the prior art that the life of the grindstone during grinding is reduced is eliminated.

Next, FIG. 6 schematically shows still another aspect of the production of the shaft-equipped superabrasive grindstone of the present invention.
In FIG. 6, the shaft-equipped superabrasive grindstone (121) has a grindstone portion (123) formed at one end of the shank portion (122), and the shank portion (122) tapers at one end in contact with the grindstone portion (123). It has a formed configuration. The superabrasive grindstone with a shaft (121) is manufactured in the same manner as the procedure described with reference to FIG. 4 except that the shank portion (122) is formed in a tapered shape.

Hereinafter, examples of the present invention will be described together with comparative examples. However, these examples illustrate the feasibility and usefulness of the present invention, and do not limit the configuration of the present invention.

1. Whetstone manufacturing test (Example)
(A) Grinding wheel material mixing ratio abrasive: Diamond # 800 0.175 g
Binder: Metal bond 1.126g
(Co = 60 wt%, Cu = 28 wt%, Sn = 12 wt%)
Concentration = 125
(B) Dimension of superabrasive grinding wheel with shaft Grinding wheel outer diameter: 3.8 mm
Groove outer diameter for processing: 1.6mm
Wheel thickness: 7.0mm
Shank part (grinding machine holding part) outer diameter: 3.0mm
Shank length: 25mm
(C) Grinding stone manufacturing procedure The shank part was formed using the SKD61 hardened material which gave the copper plating after nickel strike processing. Next, a predetermined amount of each grinding wheel material was weighed and mixed uniformly. Next, as shown in FIG. 4, the shank part is placed on the mold band, and the upper part is filled with the grindstone part material mixture, and then the upper pressing mold composed of the SKD61 quenching material is set and hot pressing is performed. It was. It was held for 60 minutes at a maximum holding temperature of 700 ° C. under a pressure of 0.2 T.
(Comparative example)
A superabrasive grindstone with a shaft was manufactured in the same manner as in the above example except that SKD61 raw material was used as the material for the shank part and the upper pressing mold.
2. Evaluation of grinding wheel physical properties (a) In the appearance examples, no particular abnormality was observed in the shank part and the upper pressing mold. On the other hand, in the comparative example, a drum-shaped deformation was observed at the boundary between the shank material and the upper pressing mold and the mold band.
(B) Hardness

As a result of using the material having the same composition, in the example using the quenching material for the shank part and the upper pressing mold, the grindstone hardness was higher than in the comparative example using the raw material, and a high density was obtained in the grindstone part. I understand that. In addition, in the shank part, the hardness decreased by hot pressing in both the example and the comparative example. However, in the comparative example, the hardness decreased so as to be deformed, whereas in the example, the workability was ensured. However, it was only reduced to a desired hardness value so that no deformation was observed.
(C) Relationship between mold temperature and hot shank hardness during hot pressing In the above examples, the relationship between hot press mold temperature and shank hardness was examined. The results are shown in the following table.

In the above table, “in-furnace time” is the accumulated time from the point when hot pressing is started.
From the above table, the hardness of the shank portion decreased, but the final hardness was 32.4 at a maximum holding temperature of 700 ° C. In the examples, deformation did not occur during hot pressing, and processing such as scraping the outer diameter of the shank portion after hot pressing could be performed without any trouble.

FIG. 1 is a schematic view of a superabrasive grindstone with a shaft. FIG. 2 is a schematic view of a silicon wafer in which a notch is formed. FIG. 3 is a diagram schematically showing one embodiment of manufacturing a conventional superabrasive grindstone with a shaft. FIG. 4 is a diagram schematically showing one embodiment of the production of a superabrasive grindstone with a shaft according to the present invention. FIG. 5 is a diagram schematically showing another aspect of manufacturing the shaft-equipped superabrasive grindstone of the present invention in which the shank portion and the grindstone portion are joined via a small-diameter bar. FIG. 6 is a diagram schematically showing still another aspect of manufacturing the shaft-equipped superabrasive grindstone of the present invention in which the shank portion is formed in a tapered shape.

11 silicon wafer; 12 notch; 13-axis superabrasive grindstone; 14-axis (shank part); 15 superabrasive layer (grindstone part); 16 processing groove; 21-axis superabrasive grindstone; 22 shank part (raw) 23 grinding wheel part; 24 mold band; 25 upper pressing mold (raw material); 26 shank part drum type deformation; 27 upper pressing mold drum type deformation; 101-shaft superabrasive grindstone; 102 shank part; 103 104 Mold band; 105 Upper pressing mold; 111 Axis superabrasive grindstone; 112 Shank part; 113 Grinding stone part; 114 Mold band; 115 Upper pressing mold; 116 Small-diameter bar; 121 Axis superabrasive grindstone 122 Shank part (tapered); 123 grinding wheel part; 124 mold band; 125 upper pressing mold

Claims (3)

  A superabrasive grindstone with a shaft in which a grindstone portion using superabrasive grains as an abrasive material is formed at one end of the shank portion, wherein the shank portion is composed of a metal material subjected to quenching or quenching / tempering, and the shank portion The metal material is selected from the group consisting of high-speed steel, hot die steel, stainless steel, and heat-resistant steel, and after the nickel strike treatment is applied to the shank portion, further copper plating is applied, and the grindstone portion is metalized with superabrasive abrasives. The above-mentioned superabrasive grindstone with a shaft, which is constituted by bonding with a bond binder, and the hardness of the shank portion after grinding of the grindstone portion is 35 to 20 on the HRC scale.   It is a manufacturing method of the superabrasive grindstone with a shaft of Claim 1, Comprising: A shank part is formed from the metal material which hardened or hardened and tempered, and the metal material of a shank part is high speed steel, hot Select from the group consisting of die steel, stainless steel and heat-resistant steel, further copper plating after nickel strike treatment to the shank part, the grindstone part is constituted by bonding superabrasive abrasive with a metal bond binder, By a hot press method in which a grinding wheel part raw material including a superabrasive abrasive and a binding material is disposed on the axial upper part of the shank part, and the grinding wheel part raw material is pressed downward in the axial direction of the shank part by an upper pressing die, Joining the grinding wheel part and the shank part, the hardness of the shank part before grinding of the grinding wheel layer is 45 or more on the HRC scale, and the hardness of the shank part after grinding of the grinding wheel part is 35 to 20 on the HRC scale. ,That , Characterized in that the upper pressing mold is be constructed from a metal material subjected to back quenching or quenching and tempering, the production method.   The method for producing a shaft-equipped superabrasive grindstone according to claim 2, wherein the metal material of the upper pressing die is selected from the group consisting of high speed steel, hot die steel, stainless steel, and heat resistant steel.

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