TWI781293B - Electroplating grindstone - Google Patents

Abstract

[Problem] To provide a plated grindstone capable of suppressing occurrence of machining defects. [Solution] A grinding stone portion is provided in which abrasive grains are fixed by a plating layer containing nickel, and talc is contained in the grinding stone portion. Moreover, in a grindstone part, you may contain the talc of 2.0 volume% or more and 15.0 volume% or less of a grindstone part. Moreover, the average particle diameter of the talc contained in a grindstone part may be 0.6 micrometer or more and 10.0 micrometer or less. In addition, the plated grindstone may be constituted only by the circular grindstone portion. In addition, the plated grindstone may be composed of an annular base having a holding portion, and a grindstone portion formed on the outer edge of the base.

Description

Electroplated grinding stone

The present invention relates to an electroplated grindstone having a grindstone portion in which abrasive grains are fixed by an electroplated layer.

Cutting devices are widely used in the cutting process of various workpieces. For example, dicing processing when dividing a semiconductor wafer into a plurality of element wafers is performed using a dicing device. In addition, in LED (Light Emitting Diode, light-emitting diode) packages, glass epoxy substrates formed by impregnating glass fibers with epoxy resin, etc. are used, and when the glass epoxy substrates are divided to obtain element packages, by The cutting device performs cutting processing.

Cutting is carried out using a ring-shaped whetstone (cutting blade) attached to the front end of the main shaft of the cutting device. The grindstone is formed, for example, by fixing abrasive grains made of diamond or the like with a plating layer containing nickel or the like. Patent Document 1 discloses a method of immersing a base plate for electroplating in an electrolyte solution such as nickel sulfate mixed with abrasive grains such as diamond, and growing a plated layer containing abrasive grains on the base plate to produce a ring-shaped grinding stone. .

When the main shaft of the cutting device is rotated and the annular whetstone cuts into the workpiece while rotating, the abrasive grains exposed from the plating layer of the whetstone come into contact with the workpiece to cut the workpiece. In addition, if the cutting process is continued, the exposed abrasive grains will fall off due to abrasion of the plating layer, and new abrasive grains will be exposed from the plating layer. This effect is called self-sharpening, and the cutting function of the whetstone is maintained by self-sharpening. [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-87282

[Problems to be Solved by the Invention] In a grindstone having abrasive grains fixed with a nickel-containing plating layer, the abrasive grains are fixed relatively strongly on the plating layer. Therefore, even if the workpiece is cut, the abrasive grains are less likely to fall off from the plating layer, and self-sharpening is less likely to occur. If the self-sharpening is not properly generated, for example, cutting chips will accumulate between the exposed abrasive grains and the cutting resistance will increase (pore clogging), and the exposed abrasive grains will become smooth due to abrasion and the sharpness of the grinding stone will decrease (grinding). Particle passivation) and other phenomena. When cutting is performed with the grindstone in such a state, machining defects such as chipping called chipping may occur on the workpiece.

In addition, it is difficult to produce self-sharpening when cutting difficult-to-cut materials such as glass, ceramics, transparent epoxy resin, or composite materials of resin and electrodes. Therefore, when using a grindstone in which abrasive grains are fixed by a plating layer containing nickel, there is a problem that it becomes more difficult to cut difficult-to-cut materials that are difficult to cut.

This invention was made in view of such a problem, and it makes it a subject to provide the electroplated grindstone which can suppress generation|occurrence|production of a processing defect.

[Technical means to solve the problem] According to one aspect of the present invention, there is provided a plated grindstone including a grindstone portion in which abrasive grains are fixed by a plating layer containing nickel, and including talc in the grindstone portion.

Moreover, in one aspect of this invention, the said grindstone part can contain the talc of 2.0 volume% or more and 15.0 volume% or less of the grindstone part. Moreover, in one aspect of this invention, the average particle diameter of the talc contained in this grindstone part may be 0.6 micrometer or more and 10.0 micrometer or less.

In addition, in one aspect of the present invention, the plated grindstone may be constituted only by the ring-shaped grindstone portion. In addition, in one aspect of the present invention, the electroplating grindstone may be composed of an annular base having a holding portion, and the grindstone portion formed on the outer edge of the base.

[Efficacy of the invention] An electroplated grindstone according to one aspect of the present invention includes a grindstone portion containing talc which is a material having lubricity lower in hardness than nickel. By using the plated grindstone for cutting processing, the self-sharpening of the plated grindstone can be promoted, the friction between the plated grindstone and a workpiece can be reduced, and the occurrence of machining defects can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment relates to a grindstone formed by electroplating (electroplated grindstone). FIG. 1(A) and FIG. 1(B) show configuration examples of plated grindstones that can be used in this embodiment.

FIG. 1(A) is a perspective view showing a configuration example of a plated grindstone 1 composed of a grindstone portion 3 . The electroplating whetstone 1 is constituted only by the annular whetstone part 3 having a through-hole 3a in the center, and the whole is a cutting edge formed by electroplating. The grindstone part 3 is formed by fixing abrasive grains, such as diamond, with the electroplating layer containing nickel, for example. The electroplated grindstone 1 constituted by the circular grindstone portion 3 is called a washer type.

FIG. 1(B) is a perspective view showing a configuration example of a plated grindstone 5 including a base 7 and a grindstone portion 9 . The plated grindstone 5 is composed of an annular base 7 having a through hole 7 a in the center and a grindstone portion 9 formed by plating on the outer edge of the base 7 . The grindstone part 9 is formed by fixing abrasive grains, such as diamond, with the electroplating layer containing nickel, for example. The plated grindstone 5 in which the grindstone portion 9 is plated on the outer edge of the base 7 is called a hub type.

In addition, the base 7 has an annular holding portion 7b protruding in the width direction at its central portion. When cutting using a cutting device, a user (operator) of the cutting device can hold the grip portion 7 b to attach the plated grindstone 5 to the cutting device.

The electroplated grinding stones 1 and 5 are installed on the front end of the main shaft arranged on the cutting device. When the main shaft is rotated in this state, the electroplating grindstones 1 and 5 rotate around the axis of the main shaft as a rotation axis. Then, the workpiece is cut by cutting into the workpiece while the plating grindstones 1 and 5 are being rotated.

In addition, there is no limitation on the material of the workpiece cut using the electroplated grindstones 1 and 5 . It can be used in the cutting process of various materials, such as semiconductor materials such as silicon or SiC, glass, ceramics, glass epoxy resin, or composite materials of resin and electrodes, etc.

Cutting of the workpiece is performed by contacting the abrasive grains exposed from the plated layers of the grindstone portions 3 and 9 to the workpiece. In addition, if the cutting process is continued, the exposed abrasive grains will fall off due to abrasion of the plating layer, and new abrasive grains will be exposed from the plating layer. This effect is called self-sharpening, and the cutting function of the whetstone is maintained by self-sharpening.

However, in the grinding stone portions 3 and 9 in which the abrasive grains are fixed by the plating layer containing nickel, the abrasive grains are fixed relatively strongly on the plating layer. Therefore, even if the workpiece is cut, the abrasive grains are less likely to fall off from the plating layer, and self-sharpening is less likely to occur. Especially when cutting glass, ceramics, glass epoxy resin, or composite materials of resin and electrodes, etc., it is difficult to produce self-sharpening when cutting materials that are difficult to process (difficult-to-cut materials). When cutting is performed with the grindstone portions 3 and 9 in such a state, machining defects such as chipping called chipping may occur on the workpiece.

Therefore, in this embodiment, the grindstone portion 3 of the plated grindstone 1 and the grindstone portion 9 of the plated grindstone 5 contain talc (hydrated magnesium silicate (Mg ₃ Si ₄ O ₁₀ (OH) ₂ )). Talc is lower in hardness than nickel (Mohs hardness 1), and if talc is included in the grinding stone portions 3 and 9, the plating layer becomes weak and easily abraded, and self-sharpening can be expected to be promoted. By appropriately generating self-sharpening and maintaining the cutting function of the plated grindstones 1 and 5, it is possible to suppress the occurrence of processing defects during cutting processing.

Furthermore, since talc is a lubricating material, if the grindstone portions 3 and 9 contain talc, the friction between the plated grindstones 1 and 5 and the workpiece can be expected to decrease during cutting. This reduction in friction suppresses the occurrence of cutting failures such as chipping (cracking) of the workpiece during cutting.

The amount of talc contained in the grinding stone parts 3 and 9 can be appropriately set according to the material of the plating layer, the material and particle size of the abrasive grains, the material of the workpiece, etc., but it is preferably set at such a level that the machining defects can be reduced and the plating grinding stone 1 and The strength of 5 can be kept above a certain range.

For example, talc can be contained in the grinding stone parts 3 and 9, and the talc content relative to the grinding stone parts 3 and 9 is 2.0 volume % to 15.0 volume %, preferably 2.2 volume % to 15.0 volume %, more preferably 2.2 volume % % or more and 6.2 volume % or less. The talc content can be measured by, for example, the Archimedes method.

In addition, the particle size of talc can also be appropriately set in the same manner as the content of talc. For example, talc having an average particle diameter of 0.6 μm or more and 10.0 μm or less when measured by a laser diffraction method can be used.

As described above, by including talc in the grindstone portions 3 and 9 in which the abrasive grains are fixed by the electroplating layer containing nickel, it is possible to suppress machining defects during cutting.

Next, an example of a method for producing a plated grindstone containing talc in the grindstone portion will be described. The plated grindstone 1 shown in FIG. 1(A) and the plated grindstone 5 shown in FIG. 1(B) can be manufactured using electrolytic plating or the like, respectively.

FIG. 2 is a cross-sectional view schematically showing a configuration example of a manufacturing apparatus 2 for manufacturing a washer-type plated grindstone 1 . As shown in FIG. 2 , when manufacturing the electroplated grinding stone 1 , first, the electroplating bath 4 containing the nickel electroplating solution 16 mixed with abrasive grains such as diamond is prepared. The material of the nickel plating solution 16 can be selected arbitrarily, for example, an electrolytic solution containing nickel such as nickel sulfate or nickel nitrate can be used.

In addition, talc contained in the grinding stone part 3 of the plating grinding stone 1 is added to the nickel plating solution 16 . Specifically, as shown in FIG. 2 , a mixed solution 18 obtained by mixing talc and a surfactant is added to the nickel plating solution 16 . This surfactant has the function of dispersing talc in the nickel plating solution 16 . In addition, the material of the surfactant can be selected arbitrarily. When the mixed solution 18 is added to the nickel electroplating solution 16 , the talc is roughly uniformly dispersed in the nickel electroplating solution 16 .

Next, the disk-shaped base 20 and the nickel electrode 6 formed of metal materials such as stainless steel and aluminum are immersed in the nickel plating solution 16 in the plating bath 4 . On the surface of the base 20, a mask 22 corresponding to the shape of the required grinding stone part 3 is formed. For example, in the case of forming an annular grinding stone part 3 as shown in FIG. A mask 22 having an annular opening.

In addition, the base 20 is connected to the negative terminal (negative pole) of the DC power supply 10 via the switch 8 , and the nickel electrode 6 is connected to the positive terminal (positive pole) of the DC power supply 10 . In addition, the switch 8 may be arranged between the nickel electrode 6 and the DC power supply 10 .

Next, the switch 8 arranged between the base 20 and the DC power supply 10 is short-circuited while the blade 14 is rotated by the rotational drive source 12 such as a motor to stir the nickel plating solution 16 . Thereby, the base 20 is used as a cathode and the nickel electrode 6 is used as an anode so that a direct current flows through the nickel electroplating solution 16, and an electroplating layer comprising nickel is electroplated in an area not covered by the mask 22 on the surface of the base 20, And the grindstone part 3 containing talc and abrasive grains is formed.

FIG. 3(A) is a cross-sectional view showing a state where the grindstone portion 3 is formed on the surface of the base 20 . As shown in FIG. 3(A), an annular grindstone portion 3 is formed on the surface of the base 20 where the mask 22 does not cover, and the talc and abrasive grains are roughly uniformly dispersed in the nickel-containing plating layer.

Thereafter, the grindstone portion 3 formed on the surface of the base 20 is peeled off from the base 20 . FIG. 3(B) is a cross-sectional view showing how the grindstone portion 3 is peeled off from the base 20 . Thereby, the grindstone part 3 is separated from the base 20, and the plated grindstone 1 of the washer type constituted by the grindstone part 3 is obtained.

In addition, the plating grindstone 5 shown in FIG.1(B) can also be manufactured by the same method as the plating grindstone 1. FIG. 4 is a cross-sectional view schematically showing a configuration example of a manufacturing device 24 used for manufacturing a hub-type plated grindstone 5 . In addition, the description of the manufacturing apparatus 2 ( FIG. 2 ) can be referred to other than the configuration described below.

First, in the same manner as the manufacturing method of the electroplating grindstone 1, the electroplating bath 4 containing the nickel electroplating solution 16 in which abrasive grains such as diamonds are mixed is prepared. Then, a mixed solution 18 obtained by mixing talc and a surfactant is added to the nickel plating solution 16 . The materials that can be used for the nickel plating solution 16 and the mixed solution 18 are the same as those for the production method of the plating grinding stone 1, so the description thereof will be omitted.

Next, the base 26 and the nickel electrode 6 formed of metal materials such as stainless steel and aluminum are immersed in the nickel plating solution 16 in the plating bath 4 . In addition, the base 26 becomes the base 7 supporting the grindstone portion 9 of the electroplating grindstone 5 through subsequent steps (see FIG. 1(B) ), so the shape of the base 26 corresponds to the shape of the base 7 .

Specifically, as shown in FIG. 5(A), the base 26 is formed in an annular shape corresponding to the shape of the base 7 of the electroplating grindstone 5, and a through hole 26a is provided in the center thereof. This through-hole corresponds to the through-hole 7a provided in the center part of the base 7 (refer FIG.1(B)).

On the surface of the base 26, a mask 28 corresponding to the shape of the desired grindstone portion 9 is formed. For example, in the case where the annular grindstone portion 9 is formed along the outer edge of the base 7 as shown in FIG. Formed circular opening. Then, in the same manner as the method of manufacturing the plated grindstone 1 , a plated layer containing nickel is plated on the surface of the base 26 where the mask 28 does not cover, and the grindstone portion 9 containing talc and abrasive grains is formed.

Afterwards, the mask 28 is removed from the submount 26 . Thereby, the base 26 with the grindstone part 9 formed on the surface is obtained. FIG. 5(A) is a cross-sectional view showing a state where the grindstone portion 9 is formed on the surface of the base 26 .

Next, by etching the outer edge of the base 26, a part of the grindstone portion 9 covering the base 26 is exposed. Thereby, as shown in FIG.5(B), the plated grindstone 5 of the hub type which formed the grindstone part 9 in the outer edge part of the base 7 was obtained. In addition, the shape of the gripping portion 7b can also be adjusted by the above-mentioned etching.

By using the above manufacturing method, the plated grindstones 1 and 5 including the grindstone portions 3 and 9 containing talc can be manufactured.

Next, the evaluation results about the plated grindstone provided with the grindstone portion containing talc will be described. Here, the workpiece is cut with a plurality of plated grindstones with different amounts of talc contained in the grindstone portion, and the size of the chipping (crack) on the workpiece generated by cutting is measured to evaluate the processing accuracy. In addition, the elastic coefficients of a plurality of plated grindstones differing in the amount of talc contained in the grindstone portion were measured, and the strength of the plated grindstones was evaluated from the elastic coefficients.

In the evaluation, a plated grindstone of the washer type (see FIG. 1(A) ) containing talc in the grindstone portion manufactured according to the above-mentioned manufacturing method was used. The plated grindstone had an outer diameter of 53.4 mm, an inner diameter of 40 mm, and a thickness of 0.10 mm, and the abrasive grains used were diamond grains with an average particle diameter of 9 μm when classified by a sieve. In addition, the concentration of abrasive grains was 50 (12.5% by volume).

Furthermore, in order to evaluate the influence of the talc content, seven types of plated grindstones containing different amounts of talc in the grindstone portion were produced. In preparation of the plated grindstone, talc having an average particle diameter of 0.8 μm as measured by a laser diffraction method was used. The amount of talc contained in the grinding stone part of the 7 types of plated grinding stones produced was measured using the Archimedes method, and each of the 7 types of grinding stones contained 0.0% by volume relative to the grinding stone part (the plated grinding stone without adding talc), 1.0% by volume, 2.2% by volume, 6.2% by volume, 11.4% by volume, 15.0% by volume and 17.5% by volume.

Next, 7 types of electroplated grinding stones were trimmed, sharpened and corrected for a perfect circle. Afterwards, the workpiece is sucked and held by the chuck table of the cutting device, and each of the seven types of plated grindstones is cut while supplying cutting water to the plated grindstone (pure water at a water temperature of 20°C) and the plated grindstone is cut into the workpiece to cut the workpiece. Workpiece processing.

Borosilicate glass having a length of 100 mm, a width of 100 mm, and a thickness of 0.4 mm was used as a workpiece. Then, the electroplated grindstone is rotated at a speed of 30000 revolutions per minute, and the lower end of the electroplated grindstone is arranged below the lower end of the workpiece, and the workpiece and the electroplated grindstone are separated by 5 mm in a direction approximately parallel to the longitudinal direction of the workpiece. /s speed to move relatively to cut the workpiece. By performing this cutting process 19 times at intervals of 5.0 mm in the width direction of the workpiece, the workpiece was divided into 20 small pieces.

Thereafter, the chuck table was rotated 90 degrees in the horizontal direction, and the workpiece was cut in a direction approximately parallel to its width direction under the same conditions to further divide each small piece into 20 pieces. In this way, the workpiece is divided into 400 wafers.

After that, 5 wafers were selected from the obtained 400 wafers, and the lengths in the direction perpendicular to the workpiece thickness direction of the cracks generated on the cut surface due to the dicing process were measured for each of the 5 wafers. Then, the maximum length of the chipping was taken as the chipping size, and the average value (average chipping size) of the chipping sizes of five wafers was calculated.

The calculation of the above-mentioned average chipping size was carried out for each of the wafers obtained by using seven types of plated grindstones with different talc contents. Fig. 6 is a graph showing the relationship between the amount of talc contained in the grinding stone portion of the plated grinding stone and the average chipping size. In addition, in Fig. 6, the average chipping size of the wafer obtained by using a plated grindstone that does not contain talc (a plated grindstone with a talc content of 0.0% by volume) is used as a reference (100%), and it shows that using other plated grindstones The ratio of the average chipping size of the resulting wafers.

As shown in FIG. 6 , when the content of talc is 2.2% by volume or more, the average crack size is significantly reduced. This is presumed to be because when the content of talc is 2.2% by volume or more, the plated layer included in the grinding stone part is weaker than talc and moderately produces self-sharpening, and the lubricating property of talc reduces the distance between the plated grinding stone and the workpiece. The friction between them, and the precision of processing is improved. Therefore, the amount of talc contained in the grindstone portion of the plated grindstone is particularly preferably 2.2% by volume or more.

Furthermore, in order to evaluate the strength of seven kinds of plated grindstones having different talc contents, the modulus of elasticity of each plated grindstone was measured. The modulus of elasticity is calculated from the stress-deflection curve obtained by loading a predetermined load on the tip before cutting the processed plated grindstone. Then, the electroplated grindstone with high elastic modulus is less likely to be deformed and has higher strength, so as to evaluate the strength of the plated grindstone.

7 is a graph showing the relationship between the amount of talc contained in the grindstone portion of the plated grindstone and the elastic coefficient of the plated grindstone. In addition, in FIG. 7 , the ratio of the elastic coefficients of other plated grindstones is shown based on the modulus of elasticity of a plated grindstone not containing talc (plated grindstone with a talc content of 0.0% by volume) as a reference (100%).

According to FIG. 7 , the modulus of elasticity of the plated grindstone having a talc content of 1.0% to 6.2% by volume is higher than that of the plated grindstone not containing talc, and the strength is improved. The reason why the modulus of elasticity of the plated grinding stone increases when such a small amount of talc is added is not clear, but it is presumed that when the amount of talc added is small, the talc particles are uniformly dispersed inside the plating layer, which inhibits the Electroplating layer transfer.

When the content of talc increases from 1.0% by volume, the modulus of elasticity decreases gradually. This is presumed to be because the plating layer included in the grinding stone portion becomes weak due to the increase in the talc content. However, in any of the plated grindstones, it was not observed that the plated grindstone deformed and meandered during cutting, and it was confirmed that each plated grindstone had the strength required for cutting the workpiece.

However, when the talc content reaches 17.5% by volume, the ratio of the modulus of elasticity is about 30%, and it can be seen that the modulus of elasticity decreases rapidly. With this plated whetstone, it may become difficult to process especially difficult-to-cut materials. Therefore, in order to reduce the average chipping size without greatly reducing the strength of the plated grindstone, it is particularly preferable to make the content of talc 2.2 vol % or more and 15.0 vol % or less.

In addition, in particular, a plated grindstone having a talc content of 6.2% by volume or less has a higher modulus of elasticity than a plated grindstone not containing talc, and the strength of the plated grindstone increases. Therefore, when the content of talc is 2.2% by volume or more and 6.2% by volume or less, the strength of the plated grindstone can be improved and the occurrence of chipping can be suppressed.

Based on the above evaluation results, by using a plated grindstone in which talc is contained in the grindstone portion, it is possible to reduce chipping during cutting and perform high-precision cutting.

In addition, the structures, methods, etc. of the above-mentioned embodiments can be implemented with appropriate changes without departing from the scope of the purpose of the present invention.

1‧‧‧Electroplated grindstone 3‧‧‧Millstone Department 3a‧‧‧through hole 5‧‧‧Electroplating grindstone 7‧‧‧Abutment 7a‧‧‧through hole 7b‧‧‧Control Department 9‧‧‧Millstone Department 2‧‧‧Manufacturing device 4‧‧‧Electroplating bath 6‧‧‧Nickel electrode 8‧‧‧Switch 10‧‧‧DC power supply 12‧‧‧rotary drive source 14‧‧‧blade 16‧‧‧Nickel plating solution 18‧‧‧Additives 20‧‧‧abutment 22‧‧‧Masking 24‧‧‧Manufacturing device 26‧‧‧Abutment 28‧‧‧Masking

1(A) in FIG. 1 is a perspective view showing a configuration example of an electroplated grindstone composed of a grindstone portion, and FIG. 1(B) is a perspective view showing a configuration example of an electroplated grindstone including a base and a grindstone portion. Fig. 2 is a cross-sectional view schematically showing a configuration example of a manufacturing apparatus used for manufacturing a washer-type plated grindstone. 3(A) in FIG. 3 is a cross-sectional view showing a state where the grindstone portion is formed on the surface of the base, and FIG. 3(B) is a cross-sectional view showing a state where the grindstone portion is peeled off from the base. Fig. 4 is a cross-sectional view schematically showing a configuration example of a manufacturing apparatus for manufacturing a hub-type plated grindstone. 5(A) is a cross-sectional view showing a state where a grindstone portion is formed on the surface of the base, and FIG. 5(B) is a cross-sectional view showing a state where a part of the grindstone portion covering the base is exposed. Fig. 6 is a graph showing the relationship between the ratio of the amount of talc contained in the grinding stone portion of the plated grinding stone and the ratio of the average chipping size. 7 is a graph showing the relationship between the amount of talc contained in the grindstone portion of the plated grindstone and the ratio of the elastic coefficient of the plated grindstone.

1‧‧‧Electroplated grindstone

3‧‧‧Millstone Department

3a‧‧‧through hole

5‧‧‧Electroplating grindstone

7‧‧‧Abutment

7a‧‧‧through hole

7b‧‧‧Control Department

9‧‧‧Millstone Department

Claims (5)

An electroplated grindstone comprising a grindstone portion in which abrasive grains are fixed by a plating layer containing nickel, the grindstone portion containing talc in an amount of 2.2% by volume to 15.0% by volume of the grindstone portion. The electroplated grindstone according to claim 1, wherein the grindstone portion contains talc in an amount of 2.2% by volume to 6.2% by volume of the grindstone portion. The plated grindstone according to claim 1 or 2, wherein the talc contained in the grindstone portion has an average particle diameter of 0.6 μm or more and 10.0 μm or less. The electroplated grindstone according to claim 1 or 2, wherein the electroplated grindstone is constituted only by the annular grindstone portion. The electroplated grindstone according to claim 1 or 2, wherein the electroplated grindstone is composed of an annular base having a holding portion, and the grindstone portion formed on the outer edge of the base.

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