JP2000094340A - Inner peripheral blade grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the service life by improving wear resistance and preventing deterioration of machining quality of a work material. SOLUTION: An electrodeposition abrasive grain layer 12 is formed by fixing super abrasive grains 14 composed of crushed abrasive grains to the whole circumference on the inner peripheral end of a base metal 11 by an electroplating phase 13. The long axis and the short axis of the super abrasive grain 14 differ in length. The abrasive grains 14 are fixed so their long axes may be approximately parallel to the front surface of the base metal 11. The abrasive grains 14 are densely arranged on the electrodeposition abrasive grain layer 12, and the abrasive grain content is in the range of 40% to 50%. If the content is not more than 40%, the wear resistance is not improved, and if the content is more than 50%, characteristics are not further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner peripheral grindstone used for producing a wafer or the like by slicing a semiconductor ingot or the like.

[0002]

2. Description of the Related Art As shown in FIG. 4, this type of inner peripheral blade grindstone has an electrodeposited abrasive layer over the entire inner periphery of a thin metal plate 1 made of SUS or the like. 2 are formed, and a number of mounting holes 3 are formed in the outer peripheral portion of the base metal 1. The electrodeposited abrasive layer 2 is formed by fixing superabrasives such as diamond and CBN to the inner peripheral end surface and both side surfaces of the inner peripheral edge of the base metal 1 by electroplating. The abrasive content in the electrodeposited abrasive layer 2 is usually about 35 to 40 vol%. In order to use such an inner peripheral grindstone, an outer peripheral portion of the base metal 1 is fixed to an annular jig and pulled up, and a workpiece such as a semiconductor ingot is rotated while the jig is rotated at a high speed. The electrodeposited abrasive grain layer 2 is cut into the work material through the center hole of the grindstone. As a result, the work material can be cut thin and a wafer can be cut out.

[0003]

In the meantime, in the inner peripheral grindstone manufactured by the conventional mechanical electroplating method, the superabrasive grains 4 fixed to the base metal 1 are formed as shown in the sectional view of FIG. They are randomly arranged in the radial direction of the base metal 1 and fixed in the metal plating phase 5 in a sparse and dense manner. For this reason, in the electrodeposited abrasive grain layer 2 corresponding to the radial side of the base metal 1, the abundance ratio of the superabrasive grains 4 may partially decrease, and the wear resistance may decrease. In this case, when the work material is cut with the inner peripheral grindstone, the shape of the electrodeposited abrasive grain layer 2 changes due to wear, so that the cutting accuracy of the wafer as the work material is reduced, and the work is not stable. However, there is a problem that the processing quality deteriorates. Further, in recent years, there has been a further demand for more efficient processing of a wafer, improvement in the life of a grinding wheel, reduction in processing cost, and the like when cutting a wafer.

The present invention has been made in view of the above circumstances, and provides an inner peripheral grindstone capable of improving abrasion resistance to prevent deterioration of work material processing quality and prolonging the life of a grindstone. Aim.

[0005]

An inner peripheral grindstone according to the present invention comprises a thin annular plate-shaped base metal and a metal plating layer formed over the entire inner peripheral edge of the base metal. In an inner peripheral grindstone having an electrodeposited abrasive layer to which superabrasive particles are fixed, the abrasive content of the electrodeposited abrasive layer is more than 40% and 50%.
And the longitudinal direction of the superabrasive is substantially parallel to the base metal. The super-abrasive grains are arranged in the electrodeposited abrasive layer in a densely packed arrangement with the longitudinal direction almost parallel to the base metal, so that the layer has the same thickness as the electrodeposited abrasive layer of the conventional inner peripheral grinding wheel. Since the structure can be enlarged and the abrasive content is high, when cutting semiconductor ingots, etc.,
The cutting ability is high, the electrodeposited abrasive layer is not easily worn, and the wear resistance is high. The electrodeposited abrasive layer has a small change in shape due to abrasion during cutting, has high processing accuracy, and has a long grinding wheel life.
Further, contact between the base metal and the work material can be avoided, and contact between the metal plating phase and the work material can be avoided, so that the chip discharge property is high, and also in this respect, the life of the grinding wheel is improved.

[0006] The superabrasive grains may be crushed abrasive grains having different major and minor axis lengths. By having super-abrasive grains whose major axes are arranged almost in parallel along the surface of the base metal,
The super-abrasive grains can be finely filled and fixed in the electrodeposited abrasive layer.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an enlarged cross-sectional view of a cutting edge portion of an inner peripheral grindstone according to an embodiment, and FIG. 2 is an external view of superabrasive grains. In the inner peripheral grindstone 10 shown in FIG. 1, the thin annular base metal 11 is made of, for example, SUS, and the inner peripheral edge 9 of the base metal 11 has an electrodeposited abrasive layer 12 having a constant width over the entire circumference. Are formed. The electrodeposited abrasive layer 12 is formed on the inner peripheral end face 9 of the base metal 11.
a and the following two side surfaces 9b, 9b.
The electrodeposited abrasive layer 12 is made of a superabrasive 14
Are fixed in multiple layers (or a single layer). Ni, Co, Cu or an alloy thereof is used as the metal plating phase 13, and diamond or CBN is used as the superabrasive grains 14. If necessary, another material may be used. The thickness of the base metal 11 is not particularly limited, but is, for example, about 0.05 to 0.5 mm. The average particle size of the superabrasive grains 14 is, for example, 20 to 100 μm for general semiconductor wafer production.

In this embodiment, crushed abrasive grains as shown in FIG. 2 are used as superabrasive grains 14, and the major axis a and the minor axis b have different lengths (a> b). It has an elongated shape. It should be noted that superabrasive grains 14 not having a longitudinal shape may be mixed. Moreover, the superabrasive grains 14 are arranged along the radial direction of the base metal 11, and are arranged such that the major axis a is substantially parallel to the radial surface of the base metal 11. Super abrasive 14
Are finely packed and arranged along the base metal 11,
The arrangement density of the superabrasive grains 14 per unit area in the medium is high. Therefore, even if the thickness of the electrodeposited abrasive layer 12 is the same as that of the conventional inner peripheral grindstone, the layer structure of the superabrasive particles 14 can be formed in a large multilayer. The abrasive content of the electrodeposited abrasive layer 12 is in the range of more than 40% to 50%. If the abrasive content is 40% or less, improvement in wear resistance cannot be obtained, and the abrasive content is 50% or less.
%, No further improvement in properties is observed.

Since the inner peripheral grindstone 10 according to the present embodiment is configured as described above, the superabrasive grains 14 are formed on the electrodeposited abrasive layer 12 such that the major axis a in the longitudinal direction is substantially parallel to the base metal 11. With such a close-packed arrangement, the layer structure of the superabrasive grains 14 can be increased with the same thickness as that of the conventional inner peripheral grindstone, and the abrasive grain content can be increased. Therefore, when cutting the semiconductor ingot, the cutting capability is high, the shape change of the electrodeposited abrasive layer 12 due to wear during the cutting is small, and the processing accuracy is good and stable. Further, the electrodeposited abrasive layer 12 is hardly worn and has high wear resistance. In addition, since the superabrasive grains 14 are arranged in a densely packed arrangement, the contact between the base metal 11 and the work material can be avoided, and further, the contact between the metal plating phase 13 and the work material can be avoided. , The chip discharge performance is improved, and the whetstone 1
0 life is improved.

A method of manufacturing such an inner peripheral blade grindstone 10 will be described. As shown in FIG. 3, an annular first spacer S1 having an inner diameter substantially equal to that of the base metal 11 is alternately provided with a plurality of base metal 11. And then set in a plating apparatus (not shown) to form an airtight space on the inner peripheral side of the base metal 11. At the center in the width direction of the inner peripheral surface 16 of the first spacer S1, a protruding ridge 17 projecting inward over the entire circumference of the inner peripheral surface 16 is formed. A predetermined distance d is provided between the side surface 9b and the side surface 9b. When the distance d is reduced, the amount of the metal plating phase 13 tends to be reduced toward the depth of the distance d.
It is possible to control the cross-sectional shape of the metal plating phase 13 by adjusting. In addition, an ultrasonic generator (not shown) is disposed in an airtight space formed inside the base metal 11 and the first spacer S1.

Then, an electrolytic plating solution containing superabrasive grains 14 is injected into an airtight space formed inside the base metal 11 and the first spacer S1, and an anode (shown in the figure) is disposed at the center of this space. ) Is connected to a power supply anode, and each base metal 11 is connected to a power supply cathode. Then, the base metal 11 and the first spacer S1
While rotating at low speed, ultrasonic waves are generated by an ultrasonic generator to vibrate the electrolytic plating solution. Then, the superabrasive grains 14 are fixed to the inner peripheral end face 9a and the side face 9b of the base metal 11 according to the dimension of the interval d. Moreover, the super-abrasive grains 1 fixed to the base metal 11 by the vibration of the electrolytic plating solution caused by ultrasonic waves.
An alignment phenomenon occurs in which the superabrasive grains 14 are aligned so that the longitudinal direction (the major axis a direction) of the superabrasive grains 14 is substantially parallel to the base metal 11 while vibrating. Therefore, superabrasive grains 14 are closely arranged and fixed almost in parallel between electroplating phases 13 to be electroplated on the surface of base metal 11. Thus, the inner peripheral grindstone 10 is manufactured. In order to arrange the superabrasive grains 14 in the electrolytic plating solution along the surface of the base metal 11, the electrolytic plating solution was vibrated by ultrasonic waves in the above description. May vibrate the electrolytic plating solution. Alternatively, instead of the electrolytic plating solution, the base metal 11 is vibrated by a vibrator or the like so that
May be aligned. Prior to the electroplating step, the superabrasive grains 14 are shaken by vibrating the electrolytic plating solution, the base metal 11 or the like.
It may be arranged on top and then electroplated.

As described above, according to the present embodiment, the superabrasive grains 14 can be densely arranged in the same thickness as the electrodeposited abrasive grain layer of the conventional inner peripheral grinding wheel, so that the layer structure can be enlarged. High grain content. Therefore, when cutting a semiconductor ingot or the like, the cutting ability is high and the electrodeposited abrasive layer 12 is hard to be worn,
High wear resistance. In addition, the change in shape due to abrasion during cutting of the electrodeposited abrasive layer 12 is small, the processing accuracy is high, and
0 life is improved. The contact between the base metal 11 and the work material can be avoided, and the contact between the metal plating phase 13 and the work material can be avoided, so that the chip discharge property is high, and also in this respect, the life of the grinding wheel 10 is improved. .

Next, an embodiment of the present invention will be described. An inner peripheral grindstone 10 (hereinafter, referred to as an example) and a conventional inner peripheral grindstone (hereinafter, a conventional example) according to the embodiment are similar to the inner peripheral grindstone for cutting a general silicon ingot. Outer diameter φ27 inch, inner diameter 240mm, blade thickness 0.3
mm and a base metal thickness of about 0.13 mm, and the thickness of one side of the side surface 9b in the electrodeposited abrasive layers 2 and 12 of the inner peripheral edge 9 of the base metals 1 and 11 was set to 0.085 mm. And
In the inner peripheral grindstone 10 according to the embodiment, the ultrasonic vibration is performed by the above-described method for manufacturing the inner peripheral grindstone using the diamond abrasive having an average particle diameter of 50 μm and an aspect ratio of 1.4 in the electrodeposited abrasive layer 12. The inner peripheral grindstone is manufactured by electroplating while vibrating the electroplating solution with an apparatus. In this case, the longitudinal direction a of the diamond abrasive grains is the inner peripheral end face 9 of the base metal 11.
a, arranged substantially parallel to the side surface 9b, and the ratio of abrasive grains present on the outer surface side (second layer) of the side surface 9b is 70 vol.
% And high. On the other hand, in the conventional example, in the electrodeposited abrasive grain layer 2, an inner peripheral edge grindstone is manufactured by ordinary electroplating using diamond abrasive grains having an average particle diameter of 50 μm and an aspect ratio of 1.4. The obtained inner peripheral blade grindstone has two layers in the thickness direction of the abrasive grains, but the ratio of the abrasive grains present in the abrasive layer array of the second layer on the outer surface side is the same as that of the first layer on the base metal 1 side. Only about 20 vol% of the grains.

With respect to the thus obtained embodiment and the conventional example, a φ6 ″ silicon ingot was mounted at a peripheral speed of 1100 m / mi.
n, and cut at a cutting speed of 50 mm. In the example, the cutting was stable even after the cutting of 500 silicon ingots was completed. On the other hand, in the conventional inner peripheral grindstone, the second abrasive layer, which is the outer surface of the base metal side, is easily worn, and when the number of cut silicon ingots reaches 100 to 200, Cutting work became unstable because the clearance decreased due to the reduced blade thickness. From the results of the cutting test described above, the inner peripheral grindstone according to the example has a higher cutting ability of the silicon ingot and a smaller change in shape of the electrodeposited abrasive layer due to abrasion as compared with the conventional example, and has abrasion resistance. High processing accuracy. The life of the whetstone was long.

[0015]

As described above, in the inner peripheral grindstone according to the present invention, the abrasive content of the electrodeposited abrasive layer is in the range of more than 40% to 50%, and the superabrasives have a long longitudinal axis. Since the direction is almost parallel to the base metal, super-abrasive grains are densely packed and arranged in the electrodeposited abrasive layer, and the layer structure is enlarged with the same thickness as the electrodeposited abrasive layer of the conventional inner peripheral grinding wheel. Because of the high abrasive grain content, when cutting semiconductor ingots, etc., the cutting ability is high and the shape change of the electrodeposited abrasive layer due to wear is small, the processing accuracy is good and the processing quality of the work material is deteriorated Can be prevented. In addition, the electrodeposited abrasive layer is hard to wear and has high abrasion resistance, which can avoid the contact between the base metal and the work material and the contact between the metal plating phase and the work material. Because of high chip discharge,
The life of the grinding wheel is improved.

Further, since the superabrasive grains are crushed abrasive grains having different major axis and minor axis lengths, the superabrasive grains are arranged with their major axes substantially parallel to the surface of the base metal. This means that the superabrasive grains can be finely filled and fixed in the electrodeposited abrasive layer.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a cutting edge portion of an inner peripheral grindstone according to an embodiment of the present invention.

FIG. 2 is an external view of crushed abrasive grains used in FIG.

FIG. 3 is a partially enlarged sectional view showing a method of manufacturing the inner peripheral grindstone shown in FIG.

FIG. 4 is a front view of a general inner peripheral blade whetstone.

FIG. 5 is an enlarged sectional view of a conventional inner peripheral grindstone.

[Explanation of symbols]

 Reference Signs List 10 inner peripheral grinding wheel 11 base metal 12 electrodeposited abrasive layer 13 metal plating phase 14 super abrasive

Claims (2)

[Claims] 1. A base metal having a thin annular plate shape, and an electrodeposited abrasive layer formed over the entire inner peripheral edge of the base metal and having superabrasive particles fixed by a metal plating layer. In the provided inner peripheral grindstone, the abrasive content of the electrodeposited abrasive layer is in a range of more than 40% to 50%, and the superabrasives are arranged so that the longitudinal direction thereof is substantially parallel to the base metal. An inner peripheral grindstone that is characterized in that: 2. An inner peripheral grinding wheel, wherein the superabrasive grains are crushed abrasive grains having different major axis and minor axis lengths.