Electrodeposition wire tool
The electroplated wire tool with alternating abrasive grain and diameter zones addresses the issues of kerf loss and workpiece damage in SiC wafer slicing by enabling high cutting performance and reduced damage through controlled concentration and diameter variations.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ASAHI DIAMOND IND
- Filing Date
- 2025-10-27
- Publication Date
- 2026-05-15
AI Technical Summary
Conventional electroplated wire tools for slicing SiC wafers using fixed abrasive grains suffer from large kerf loss, inferior wafer quality, and difficulty in achieving a high cutting edge due to uniform abrasive grain concentration and large grain sizes, which also cause workpiece damage.
An electroplated wire tool with alternating high, low, and intermediate abrasive grain concentration regions, along with varying wire diameters, allowing for a self-sharpening effect and reduced kerf loss, even with small abrasive grains.
The solution achieves high cutting performance, reduces kerf loss, and minimizes workpiece damage by utilizing small abrasive grains and controlled concentration zones, enhancing the self-sharpening action.
Smart Images
Figure JP2025037644_15052026_PF_FP_ABST
Abstract
Description
Electroplated wire tool
[0001] The present disclosure relates to an electroplated wire tool.
[0002] Conventionally, as a slicing process for SiC wafers, there are a free abrasive grain method in which slicing is performed while supplying a cutting fluid containing abrasive grains to a wire row, and a fixed abrasive grain method in which slicing is performed using an electroplated wire tool (for example, see Patent Document 1) in which abrasive grains are electroplated on a wire.
[0003] Japanese Patent Application Laid-Open No. 2020-001116
[0004] The fixed abrasive grain method has the advantage of shorter processing time compared to the free abrasive grain method. However, the electroplated wire tool used in the fixed abrasive grain method is generally one in which abrasive grains larger than those used in the free abrasive grain method are electroplated on the wire. Therefore, the fixed abrasive grain method has the disadvantage of a large kerf loss. In addition, the fixed abrasive grain method is also slightly inferior in terms of wafer quality of the sliced wafer. Moreover, since the conventional electroplated wire tool has a uniform concentration of abrasive grains over the entire length of the wire, there is also a problem that it is difficult to obtain a high cutting edge.
[0005] Therefore, an object of the present disclosure is to provide an electroplated wire tool that can obtain a high cutting edge even when using abrasive grains with a small particle size, can reduce the kerf loss, and can reduce the damage to the workpiece.
[0006] [1] The electroplated wire tool according to the present disclosure is an electroplated wire tool in which abrasive grains are electroplated on a wire, and includes a high concentration region, a low concentration region where the concentration of the abrasive grains is lower than that of the high concentration region, and an intermediate concentration region where the concentration of the abrasive grains is intermediate between the high concentration region and the low concentration region. In the longitudinal direction of the wire, the high concentration region and the low concentration region are alternately repeated, and the intermediate concentration region is disposed between the high concentration region and the low concentration region.
[0007] In this electroplated wire tool, high-concentration and low-concentration regions alternate along the longitudinal direction of the wire. Therefore, each time the point of contact with the workpiece shifts from a low-concentration region to a high-concentration region, the abrasive grains can abut the workpiece over a large area. This allows for an effect similar to the self-sharpening action of the abrasive grains, enabling high cutting performance even when using small-grained abrasive grains. Furthermore, the use of small-grained abrasive grains reduces kerf loss and minimizes damage to the workpiece. Moreover, because the intermediate-concentration region is positioned between the high-concentration and low-concentration regions, damage to the workpiece due to abrupt changes in concentration can be reduced.
[0008] [2] In the electroplated wire tool described in [1], the average particle size of the abrasive grains may be 1 μm or more and 80 μm or less. In this electroplated wire tool, since the average particle size of the abrasive grains is 1 μm or more and 80 μm or less, it is possible to reduce kerf loss while ensuring cutting performance and to reduce damage to the workpiece.
[0009] [3] In the electroplated wire tool described in [1] or [2], the average wire diameter in the low concentration region is smaller than the average wire diameter in the high concentration region, and the average wire diameter in the intermediate concentration region may be intermediate between the average wire diameter in the high concentration region and the average wire diameter in the low concentration region. In this electroplated wire tool, since the average wire diameter in the low concentration region is smaller than the average wire diameter in the high concentration region, the abrasive grains can be brought into contact with the workpiece over a large area each time the position of contact with the workpiece moves from the low concentration region to the high concentration region. This makes it possible to produce an effect similar to the self-sharpening action of the abrasive grains, so that high cutting performance can be obtained even when using abrasive grains with small particle sizes. Moreover, since the average wire diameter in the intermediate concentration region is intermediate between the average wire diameter in the high concentration region and the average wire diameter in the low concentration region, damage to the workpiece due to abrupt changes in the average wire diameter can be reduced.
[0010] [4] In the electroplated wire tool described in [3], the difference between the average wire diameter in the high concentration region and the average wire diameter in the intermediate concentration region may be 5% or more and 80% or less of the average particle size of the abrasive grains, and the difference between the average wire diameter in the intermediate concentration region and the average wire diameter in the low concentration region may be 5% or more and 80% or less of the average particle size of the abrasive grains. In this electroplated wire tool, since the difference between the average wire diameter in the high concentration region and the average wire diameter in the intermediate concentration region is 5% or more and 80% or less of the average particle size of the abrasive grains, and the difference between the average wire diameter in the intermediate concentration region and the average wire diameter in the low concentration region is 5% or more and 80% or less of the average particle size of the abrasive grains, an effect similar to the self-sharpening action of the abrasive grains can be appropriately expressed, and damage to the workpiece can be appropriately reduced.
[0011] According to this disclosure, high cutting performance can be obtained even when using abrasive grains with small particle sizes, kerf loss can be reduced, and damage to the workpiece can be reduced.
[0012] Figure 1 is a schematic front view showing the electroplated wire tool of this embodiment. Figure 2 is a schematic diagram illustrating the method for measuring the concentration of abrasive grains. Figure 3 is a schematic diagram illustrating the method for measuring the concentration of abrasive grains. Figure 4 is a schematic diagram illustrating the method for measuring the average wire diameter of the electroplated wire tool. Figure 5 is a schematic cross-sectional view of the high concentration region. Figure 6 is a schematic cross-sectional view of the low concentration region. Figure 7 is a schematic cross-sectional view of the intermediate concentration region. Figure 8 is a graph showing the measurement results for Example 1, Comparative Example 1, and Comparative Example 2.
[0013] Embodiments of this disclosure will be described in detail below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.
[0014] Figure 1 is a schematic front view showing the electroplated wire tool of this embodiment. The electroplated wire tool 1 shown in Figure 1 is mounted on a wire saw used for slicing workpieces such as SiC wafers. As shown in Figure 1, the electroplated wire tool 1 of this embodiment comprises a long wire 2 and abrasive grains 3 electroplated on the surface of the wire 2.
[0015] The diameter of wire 2 is, for example, 0.06 mm or more and 0.16 mm or less.
[0016] For example, diamond or CBN can be used as the abrasive grain 3.
[0017] The average particle size of the abrasive grains 3 is, for example, between 1 μm and 80 μm. The average particle size of the abrasive grains 3 is measured as follows: First, the particle size of the abrasive grains 3 before they are electrodeposited onto the wire 2 is measured using a laser diffraction / scattering device, and a particle size distribution (histogram) is obtained. A Microtrac SYNC particle size distribution / particle shape analyzer is used as the laser diffraction / scattering device. Then, D50, which is the median of the obtained particle size distribution (histogram), is taken as the average particle size of the abrasive grains 3.
[0018] The electroplated wire tool 1 has a high-concentration region 4 in which the abrasive grains 3 are highly concentrated, a low-concentration region 5 in which the abrasive grains 3 are less concentrated than in the high-concentration region 4, and an intermediate-concentration region 6 in which the abrasive grains 3 are between the high-concentration region 4 and the low-concentration region 5.
[0019] The concentration of abrasive grains 3 is the number of abrasive grains per unit length observed on the ridge portion of the electroplated wire tool 1. The concentration of abrasive grains 3 is measured as follows. First, a projection image of the electroplated wire tool 1 is taken. The projection image of the wire is taken by using backlight illumination and imaging the electroplated wire tool 1 with a camera, for example, as shown in Figure 2. Figure 2 is a schematic diagram illustrating the method for measuring the concentration of abrasive grains. Next, as shown in Figure 3, the average brightness on the Y axis of the measurement range in the captured image is compared while sliding in the X axis direction, and areas with large changes are detected as edges. Figure 3 is a schematic diagram illustrating the method for measuring the concentration of abrasive grains. The X axis is the direction of extension of the electroplated wire tool 1, and the Y axis is the direction perpendicular to the X axis. Then, the number of detected edges is used as the number of abrasive grains 3 observed on the ridge portion of the electroplated wire tool 1, and the number of abrasive grains per unit length observed on the ridge portion of the electroplated wire tool 1 is calculated. The unit length is 1 mm.
[0020] The concentration of abrasive grains 3 in the high concentration region 4 is, for example, 30 to 50. The concentration of abrasive grains 3 in the low concentration region 5 is, for example, 0 to 30. The concentration of abrasive grains 3 in the intermediate concentration region 6 is, for example, 15 to 40.
[0021] Each of the high-concentration region 4, low-concentration region 5, and intermediate-concentration region 6 is a region of a predetermined length in the longitudinal direction L of the wire 2. In the longitudinal direction L of the wire 2, the high-concentration region 4 and the low-concentration region 5 are alternately repeated, and the intermediate-concentration region 6 is located between the high-concentration region 4 and the low-concentration region 5. Preferably, the intermediate-concentration region 6 is located between all of the high-concentration region 4 and the low-concentration region 5, but it may also be located between some of the high-concentration region 4 and the low-concentration region 5. For example, in a wire saw or the like to which an electroplated wire tool 1 is attached, if the electroplated wire tool 1 moves in only one direction, the intermediate-concentration region 6 may be located only between the high-concentration region 4 and the low-concentration region 5 in the direction in which the electroplated wire tool 1 moves. Alternatively, one intermediate-concentration region 6 may be located for each predetermined repeating unit in which the high-concentration region 4 and the low-concentration region 5 are repeated a predetermined number of times.
[0022] The length of the intermediate concentration region 6 in the longitudinal direction L may be shorter than the length of the high concentration region 4 and the low concentration region 5 in the longitudinal direction L. The length of the high concentration region 4 in the longitudinal direction L is, for example, 1 mm to 300 mm, preferably 5 mm to 150 mm, and more preferably 10 mm to 80 mm. The length of the low concentration region 5 in the longitudinal direction L is, for example, 1 mm to 300 mm, preferably 5 mm to 150 mm, and more preferably 10 mm to 80 mm. The length of the intermediate concentration region 6 in the longitudinal direction L is, for example, 1 mm to 300 mm, preferably 5 mm to 150 mm, and more preferably 10 mm to 80 mm. Also, the length of the intermediate concentration region 6 in the longitudinal direction L is, for example, 10% to 100% of the length of the high concentration region 4 in the longitudinal direction L. The length of the intermediate concentration region 6 in the longitudinal direction L is, for example, 10% to 100% of the length of the low concentration region 5 in the longitudinal direction L.
[0023] The average wire diameter D of the electroplated wire tool 1 is measured as follows. First, as shown in Figure 4, the wire diameter is measured at five locations (1), (2), (3), (4), and (5) of the electroplated wire tool 1 from four directions using a micrometer. Figure 4 is a schematic diagram illustrating the method for measuring the average wire diameter of the electroplated wire tool. The four directions for measurement are 45 degrees apart from each other. This yields 20 wire diameters. The average of these 20 wire diameters is then taken as the average wire diameter D of the electroplated wire tool 1.
[0024] Figure 5 is a schematic cross-sectional view of the high-concentration region. Figure 6 is a schematic cross-sectional view of the low-concentration region. Figure 7 is a schematic cross-sectional view of the intermediate-concentration region. As shown in Figures 5 to 7, as the concentration of abrasive grains 3 decreases, the area on the wire 2 where abrasive grains 3 are not present increases, and the average wire diameter D of the electroplated wire tool 1 decreases. For this reason, the average wire diameter D2 of the electroplated wire tool 1 in the low-concentration region 5 is smaller than the average wire diameter D1 of the electroplated wire tool 1 in the high-concentration region 4. Also, the average wire diameter D3 of the electroplated wire tool 1 in the intermediate-concentration region 6 is intermediate between the average wire diameter D1 of the electroplated wire tool 1 in the high-concentration region 4 and the average wire diameter D2 of the electroplated wire tool 1 in the low-concentration region 5.
[0025] The average wire diameter D3 of the electroplated wire tool 1 in the intermediate concentration region 6 is, for example, 90% to 99% of the average wire diameter D1 of the electroplated wire tool 1 in the high concentration region 4. The average wire diameter D2 of the electroplated wire tool 1 in the low concentration region 5 is, for example, 90% to 99% of the average wire diameter D3 of the electroplated wire tool 1 in the intermediate concentration region 6.
[0026] The difference between the average wire diameter D1 of the electroplated wire tool 1 in the high-concentration region 4 and the average wire diameter D3 of the electroplated wire tool 1 in the intermediate-concentration region 6 is, for example, 5% to 80% of the average particle size of the abrasive grains 3, preferably 10% to 60%, and more preferably 20% to 40%. The difference between the average wire diameter D3 of the electroplated wire tool 1 in the intermediate-concentration region 6 and the average wire diameter D2 of the electroplated wire tool 1 in the low-concentration region 5 is, for example, 5% to 80% of the average particle size of the abrasive grains 3, preferably 10% to 60%, and more preferably 20% to 40%.
[0027] As described above, in the electroplated wire tool 1 according to this embodiment, high-concentration regions 4 and low-concentration regions 5 are alternately repeated in the longitudinal direction L of the wire 2. Therefore, each time the position in contact with the workpiece moves from the low-concentration region 5 to the high-concentration region 4, the abrasive grains 3 can abut the workpiece over a large area. This makes it possible to produce an effect similar to the self-sharpening action of the abrasive grains 3, so that high cutting performance can be obtained even when using abrasive grains 3 with small particle sizes. Furthermore, because small-particle abrasive grains 3 can be used, kerf loss can be reduced and damage to the workpiece can be reduced. Moreover, since the intermediate concentration region 6 is located between the high-concentration region 4 and the low-concentration region 5, damage to the workpiece due to abrupt changes in concentration can be reduced.
[0028] Furthermore, in this electroplated wire tool 1, since the average particle size of the abrasive grains 3 is between 1 μm and 80 μm, it is possible to reduce kerf loss while ensuring cutting performance, and to reduce damage to the workpiece.
[0029] Furthermore, in this electroplated wire tool 1, the average wire diameter D2 in the low-concentration region 5 is smaller than the average wire diameter D1 in the high-concentration region 4. Therefore, each time the position of contact with the workpiece moves from the low-concentration region 5 to the high-concentration region 4, the abrasive grains 3 can abut the workpiece over a large area. This allows the abrasive grains 3 to exhibit an effect similar to self-sharpening, so that high cutting performance can be obtained even when using abrasive grains 3 with small particle sizes. Moreover, since the average wire diameter D3 in the intermediate-concentration region 6 is intermediate between the average wire diameter D1 in the high-concentration region 4 and the average wire diameter D2 in the low-concentration region 5, damage to the workpiece due to abrupt changes in the average wire diameter can be reduced.
[0030] Furthermore, in this electroplated wire tool 1, the difference between the average wire diameter D1 in the high-concentration region 4 and the average wire diameter D3 in the intermediate-concentration region 6 is 5% to 80% of the average particle size of the abrasive grains 3, preferably 10% to 60%, and more preferably 20% to 40%. The difference between the average wire diameter D3 in the intermediate-concentration region 6 and the average wire diameter D2 in the low-concentration region 5 is 5% to 80% of the average particle size of the abrasive grains 3, preferably 10% to 60%, and more preferably 20% to 40%. As a result, an effect similar to the self-sharpening action of the abrasive grains 3 can be appropriately expressed, and damage to the workpiece can be appropriately reduced.
[0031] This disclosure is not limited to the embodiments described above and may be modified as appropriate without departing from the spirit of this disclosure.
[0032] Next, embodiments of the present disclosure will be described. However, the present disclosure is not limited to the embodiments shown below.
[0033] (Example 1) In Example 1, an electroplated wire tool was fabricated in which high-concentration regions and low-concentration regions were alternately repeated, with intermediate-concentration regions positioned between the high-concentration and low-concentration regions. The wire diameter was 0.14 mm. Diamond was used as the abrasive grain. The average particle size of the abrasive grain was 9 μm. The concentration of abrasive grains in the high-concentration region was set to 50, in the low-concentration region to 30, and in the intermediate-concentration region to 40. Then, a SiC wafer was cut using the fabricated electroplated wire tool.
[0034] Subsequently, the amount of curvature of the cut cross-section of the SiC wafer was measured. The amount of curvature was defined as the displacement relative to a reference plane, with the plane extending in the direction of the cut from the cut start position being used as the reference plane. The measurement results are shown in Figure 8. In Figure 8, the horizontal axis represents the cut depth (mm), and the vertical axis represents the amount of curvature (μm).
[0035] (Comparative Example 1) An electroplated wire tool was fabricated in the same manner as in Example 1, except that the entire area of the electroplated wire tool was made into a low-concentration region. Then, a SiC wafer was cut using the fabricated electroplated wire tool, and the amount of bending of the cut cross-section of the SiC wafer was measured. The measurement results are shown in Figure 8.
[0036] (Comparative Example 2) An electroplated wire tool was fabricated in the same manner as in Example 1, except that the entire area of the electroplated wire tool was made into a high-concentration region. Then, a SiC wafer was cut using the fabricated electroplated wire tool, and the amount of bending of the cut cross-section of the SiC wafer was measured. The measurement results are shown in Figure 8.
[0037] (Evaluation) As shown in Figure 8, Example 1 showed a significantly smaller amount of curvature in the cut cross-section of the SiC wafer compared to Comparative Examples 1 and 2. This means that Example 1 showed a significantly improved straightness of the electroplated wire tool compared to Comparative Examples 1 and 2. From this result, it is presumed that in Example 1, a high level of cutting performance was achieved by exhibiting an effect similar to the self-sharpening action of the abrasive grains 3.
[0038] 1... Electroplated wire tool, 2... Wire, 3... Abrasive grain, 4... High concentration region, 5... Low concentration region, 6... Intermediate concentration region, D... Average wire diameter, D1... Average wire diameter in the high concentration region, D2... Average wire diameter in the low concentration region, D3... Average wire diameter in the intermediate concentration region, L... Longitudinal direction.
Claims
1. An electroplated wire tool in which abrasive grains are electroplated onto a wire, comprising: a high-concentration region; a low-concentration region in which the concentration of abrasive grains is lower than that of the high-concentration region; and an intermediate-concentration region in which the concentration of abrasive grains is intermediate between that of the high-concentration region and the low-concentration region, wherein the high-concentration region and the low-concentration region are alternately repeated in the longitudinal direction of the wire, and the intermediate-concentration region is located between the high-concentration region and the low-concentration region.
2. The electroplated wire tool according to claim 1, wherein the average particle size of the abrasive grains is 1 μm or more and 80 μm or less.
3. The electroplated wire tool according to claim 1 or 2, wherein the average wire diameter in the low concentration region is smaller than the average wire diameter in the high concentration region, and the average wire diameter in the intermediate concentration region is intermediate between the average wire diameter in the high concentration region and the average wire diameter in the low concentration region.
4. The difference between the average wire diameter in the high concentration region and the average wire diameter in the intermediate concentration region is 5% to 80% of the average particle size of the abrasive grains, and the difference between the average wire diameter in the intermediate concentration region and the average wire diameter in the low concentration region is 5% to 80% of the average particle size of the abrasive grains, as described in claim 3.