Design method of workpiece carrier

Abstract

To provide a design method of a workpiece carrier for forming a workpiece carrier on which a second opening in consideration of a flow of an abrasive is designed.SOLUTION: The design method includes: setting a holding hole region where a first opening is formed; setting an abrasive supply region which needs the supply of an abrasive to the inside of the holding hole region; calculating, by every radial position of a carrier substrate, an area ratio of the abrasive supply region along a circumferential direction of a carrier substrate; setting a region obtained by subtracting the holding hole region from the whole region of the carrier substrate as a possible region where a second opening can be formed; calculating, by every radial position of the carrier substrate, an area ratio of the possible region along the circumferential direction of the carrier substrate; comparing the area ratio of the abrasive supply region with the area ratio of the possible region to set the smaller one as a design ratio; setting, by every radial position of the carrier substrate, a ratio of an area of the second opening along the circumferential direction of the carrier substrate on the basis of the design ratio; and designing the second opening satisfying a ratio of the set area, inside the possible region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for designing a work carrier. [Background technology]

[0002] Conventionally, as a work carrier used to hold a workpiece when polishing the workpiece with a polishing device, a work carrier has been known in which a first opening for holding the workpiece and a second opening for passing an abrasive (holding the abrasive) without holding the workpiece are formed in a carrier substrate (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-22542 [Patent Document 2] Japanese Patent Application Publication No. 2018-47552 Summary of the Invention [Problem to be solved by the invention]

[0004] It has been confirmed that differences in the design of the second opening, such as the size and arrangement of the second opening in the work carrier, tend to result in different workpiece processing accuracy. That is, it is believed that the flow of the abrasive supplied between the polishing surface of the polishing device, the work carrier, and the workpiece differs depending on the size and arrangement of the second opening formed in the carrier substrate. However, in conventional work carriers, the size and arrangement of the second opening are set with the goal of supplying a sufficient amount of abrasive while suppressing deformation of the carrier substrate, and the effect of the flow of the abrasive on the workpiece processing accuracy has not been taken into consideration.

[0005] The present invention has been made with an eye on the above-mentioned problems, and aims to provide a method for designing a work carrier for forming a work carrier in which a second opening is designed taking into account the flow of abrasives. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a method for designing a work carrier for forming a first opening for holding a workpiece and a second opening for not holding the workpiece in a carrier substrate, the method comprising: a first step of setting a holding hole region in which the first opening is to be formed in the carrier substrate; a second step of setting an abrasive supply region that requires the supply of abrasive inside the holding hole region; a third step of calculating the ratio of an area of ​​the abrasive supply region along the circumferential direction of the carrier substrate for each radial position of the carrier substrate; and a third step of calculating an area obtained by subtracting at least the holding hole region from the entire area of ​​the carrier substrate as a possible area in which the second opening can be formed. a fourth step of calculating the area ratio of the possible area along the circumferential direction of the carrier substrate for each radial position of the carrier substrate; a sixth step of comparing the area ratio of the abrasive supply area and the area ratio of the possible area for each radial position of the carrier substrate and setting the smaller one as a design ratio; a seventh step of setting the area ratio of the second opening along the circumferential direction of the carrier substrate for each radial position of the carrier substrate based on the design ratio; and an eighth step of designing the second opening that satisfies the area ratio set in the seventh step inside the possible area. [Effects of the Invention]

[0007] This makes it possible to provide a method for designing a work carrier for forming a work carrier in which the second opening is designed in consideration of the flow of the abrasive. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view showing a work carrier according to a first embodiment. [Figure 2]1 is a flowchart showing the flow of a design procedure for an abrasive holding hole in Example 1. [Figure 3] 4 is an explanatory view showing holding hole regions set in the work carrier of the first embodiment. FIG. [Figure 4] 3 is an explanatory diagram showing an abrasive suppression area and an abrasive supply area set in the work carrier of the first embodiment. FIG. [Figure 5] 1 is a map showing the area ratio of an abrasive supply region in Example 1. [Figure 6] 3 is an explanatory diagram showing a restricted area set in the work carrier of the first embodiment. FIG. [Figure 7] 4 is an explanatory diagram showing a possible area set in the work carrier of the first embodiment. FIG. [Figure 8] 10 is a map showing the area ratio of the possible region in Example 1. [Figure 9] 1 is a map showing design ratios in Example 1. [Figure 10] 1 is a map showing the area ratio of abrasive holding holes in Example 1. [Figure 11] 3A and 3B are explanatory views showing design examples of abrasive holding holes in Example 1. FIG. [Figure 12] FIG. 10(a) is a plan view showing a work carrier of a first modified example, and FIG. 10(b) is an explanatory diagram showing a holding hole area, an abrasive supply area, a restricted area, and a possible area set in the work carrier of the first modified example. [Figure 13] 10(a) is a map showing the area ratio of the abrasive supplying region, the area ratio of the possible region, and the design ratio of the first modified example, and FIG. 10(b) is a map showing the area ratio of the abrasive holding hole of the first modified example. [Figure 14] (a) is a plan view showing a work carrier of a second modified example, and (b) is an explanatory diagram showing the retaining hole area, abrasive suppression area, abrasive supply area, restriction area, and possible area set in the work carrier of the second modified example. [Figure 15] (a) is a plan view showing a work carrier of a third modified example, and (b) is an explanatory diagram showing the retaining hole area, abrasive suppression area, abrasive supply area, restriction area, and possible area set in the work carrier of the third modified example. [Figure 16] 10(a) is a map showing the area ratio of the abrasive supplying region, the area ratio of the possible region, and the design ratio of the third modified example, and FIG. 10(b) is a map showing the area ratio of the abrasive holding hole of the third modified example. [Figure 17] 10(a) is a plan view showing a work carrier of a fourth modified example, and FIG. 10(b) is a map showing the area ratio of the abrasive holding holes of the fourth modified example. [Figure 18] 10(a) is a plan view showing a work carrier of a fifth modified example, and FIG. 10(b) is a map showing the area ratio of the abrasive holding holes of the fifth modified example. [Figure 19] 10(a) to 10(e) are plan views of the work carrier showing modified examples of the abrasive holding holes. [Figure 20] (a) is a map showing the area ratio of the abrasive supply area of ​​the work carrier of the sixth modified example, and (b) is a map showing the area ratio of the abrasive supply area, the area ratio of the possible area, and the design ratio of the sixth modified example. [Figure 21] FIG. 13 is a plan view showing a work carrier of a sixth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a mode for carrying out a method for designing a work carrier of the present invention will be described based on Example 1 shown in the drawings.

[0010] The work carrier 10 of Example 1 is mounted on a surface polishing device that polishes both sides or one side of a thin workpiece. For example, a surface polishing device that polishes both sides of a workpiece includes upper and lower surface plates, sun gears located at the centers of the upper and lower surface plates, and internal gears located on the outer peripheries of the upper and lower surface plates. The upper and lower surface plates, the sun gear, and the internal gear are all rotatable. During polishing of the workpiece, an abrasive is supplied between the upper and lower surface plates through a hole that penetrates the upper surface plate.

[0011] The work carrier 10 shown in FIG. 1 is disposed between an upper surface plate and a lower surface plate of the surface polishing machine.

[0012] The main body of the work carrier 10 is formed by a disk-shaped carrier substrate 1. The carrier substrate 1 is perforated with a plurality of workpiece holding holes 2 (four circular holes in FIG. 1) and a plurality of abrasive holding holes 3 (four holes in FIG. 1).

[0013] The carrier substrate 1 is formed by cutting a metal plate, resin plate, ceramic plate, or other plate material into a disk shape. Examples of suitable metal plates include stainless steel (SUS), high-carbon chromium bearing steel, carbon tool steel (SK steel), high-speed tool steel, alloy tool steel, high-tensile steel, and titanium. Examples of suitable resin plates include polyamide (PA), polyacetal (POM), polyvinyl chloride (PVC), polycarbonate (PC), polyimide (PI), polyamide-imide (PAI), epoxy (EP), and fiber-reinforced plastic (FRP), which is a composite of resin and fibers such as glass fiber, carbon fiber, and aramid fiber. When the carrier substrate 1 is formed from a metal plate, a resin insert (not shown) may be provided along the inner circumferential surface 21 of the workpiece-holding hole 2, if necessary.

[0014] The work carrier 10 has teeth on its outer periphery 11, which is the outer edge of the carrier substrate 1, that mesh with the sun gear and internal gear of the surface polishing machine. The work carrier 10 rotates and revolves around its axis due to the rotation of the sun gear and internal gear. As the work carrier 10 rotates and revolves around its axis, both sides of the work placed in the work holding hole 2 of the work carrier 10 are polished by the polishing surfaces of the upper and lower surface plates.

[0015] The workpiece holding holes 2 are first openings that penetrate the carrier substrate 1 in the thickness direction, and hold the workpieces placed inside. The workpiece holding holes 2 are formed in a holding hole area A (see FIG. 3 ), which will be described later, that is set in the carrier substrate 1, and here, four workpiece holding holes 2 are arranged at positions that are point-symmetric with respect to the center O of the carrier substrate 1.

[0016] The abrasive holding hole 3 is a second opening that penetrates the carrier substrate 1 in the thickness direction and holds an abrasive. The abrasive holding hole 3 is an opening of a size that can hold the abrasive supplied from the upper surface plate to the lower surface plate during polishing of the workpiece. The abrasive held in the abrasive holding hole 3 flows out of the abrasive holding hole 3 during polishing of the workpiece and is supplied to the polishing surfaces of the upper surface plate and the lower surface plate. Note that no workpiece is placed inside the abrasive holding hole 3, and the abrasive holding hole 3 is an opening that does not hold a workpiece formed on the carrier substrate 1.

[0017] The abrasive holding holes 3 are formed in a later-described possible area E (see FIG. 7) set in the carrier substrate 1. Here, four abrasive holding holes 3 are arranged at positions that are point-symmetric with respect to the center O of the carrier substrate 1, and are lined up at regular intervals (equal intervals) along the circumferential direction of the carrier substrate 1. Moreover, as shown in FIG. 1, the abrasive holding holes 3 of Example 1 are arranged between adjacent workpiece holding holes 2, and when the workpiece carrier 10 is viewed from above, they have a fan-like shape that gradually widens as they move radially outward from the carrier substrate 1.

[0018] Fig. 2 is a flowchart showing the flow of the design procedure for the abrasive holding holes 3 of Example 1. Each step of the flowchart in Fig. 2 will be described below. Note that the design of the abrasive holding holes 3 may be performed automatically using a computer or the like, or may be performed manually.

[0019] In step S1, the entire area of ​​the carrier substrate 1 is set based on the size and shape of the carrier substrate 1, and the process proceeds to step S2.

[0020] In step S2, following the setting of the entire area of ​​the carrier substrate 1 in step S1, a holding hole area A is set within the carrier substrate 1, and the process proceeds to step S3. Here, the "holding hole area A" is the area in the carrier substrate 1 where the work holding holes 2 are formed, and is indicated by diagonal lines slanting upward to the right in Fig. 3. The holding hole area A is set arbitrarily based on the size and shape of the carrier substrate 1, the size and number of workpieces to be held by the work carrier 10, etc.

[0021] In step S3, following the setting of the retaining hole area A in step S2, it is determined whether or not it is necessary to set an abrasive suppression area B inside the retaining hole area A. If YES (abrasive suppression area B needs to be set), proceed to step S4; if NO (abrasive suppression area B does not need to be set), proceed to step S6. Here, the "abrasive suppression area B" is an area within the retaining hole area A that suppresses the supply of abrasive. Whether or not an abrasive suppression area B needs to be set is determined based on the amount of abrasive supplied to the retaining hole area A, the distribution of the abrasive supply, the amount of workpiece polished, etc.

[0022] In step S4, following the determination in step S3 that it is necessary to set the abrasive suppression area B, the abrasive suppression area B is set inside the holding hole area A, and the process proceeds to step S5. Here, the abrasive suppression area B is set based on the trajectory of the workpiece during polishing, the polishing amount of the workpiece, the target abrasive supply distribution, etc. In the work carrier 10 of Example 1, as shown by fine dots in Fig. 4, the abrasive suppression area B is set as an annular area of ​​a predetermined width along the inside edge of the holding hole area A indicated by the dashed line.

[0023] In step S5, following the setting of the abrasive suppression region B in step S4, the area obtained by subtracting the abrasive suppression region B from the holding hole region A is set as the abrasive supply region C (shown by coarse dots in FIG. 4), and the process proceeds to step S7. Here, the "abrasive supply region C" is the region within the holding hole region A where the supply of abrasive is desired. In other words, the abrasive supply region C is the region within the holding hole region A where the supply of abrasive is required.

[0024] In step S6, following the determination in step S3 that it is not necessary to set the abrasive suppression region B, the entire holding hole region A is set as the abrasive supply region C, and the process proceeds to step S7.

[0025] In step S7, following the setting of the abrasive supply region C in step S5 or step S6, the area ratio of the abrasive supply region C is calculated, and the process proceeds to step S8. Here, the "area ratio of the abrasive supply region C" refers to the ratio of the area of ​​the abrasive supply region C to the area of ​​the carrier substrate 1 along the circumferential direction of the carrier substrate 1, and is calculated for each radial position of the carrier substrate 1. As shown in FIG. 5, the area ratio of the abrasive supply region C can be represented on a map with the radial position of the carrier substrate 1 on the horizontal axis and the area ratio of the abrasive supply region C on the vertical axis. Regarding the radial position of the carrier substrate 1 on the map, "zero" indicates the position of the center O, and the position increases as the distance from the center O increases, while "MAX" indicates the position of the outer periphery 11 of the carrier substrate 1. The area ratio of the abrasive supply region C is "zero%" when no abrasive supply region C exists on a circular line along the circumferential direction of the carrier substrate 1 at a certain radial position. The area ratio of the abrasive supply region C is "100%" when, at a certain radial position, the abrasive supply region C exists over the entire circumferential direction of the carrier substrate 1. Note that Fig. 5 shows the area ratio of the abrasive supply region C (the abrasive supply region C set in step S5) when the abrasive suppression region B is set.

[0026] In step S8, following the calculation of the area ratio of the abrasive supply region C in step S7, it is determined whether or not it is necessary to set a restricted region D. If YES (setting of restricted region D is necessary), proceed to step S9; if NO (setting of restricted region D is not necessary), proceed to step S11. Here, the "restricted region D" is the region in which the formation of the abrasive holding holes 3 is restricted in the region obtained by subtracting the holding hole region A from the entire area of ​​the carrier substrate 1 (the region outside the holding hole region A). Whether or not it is necessary to set a restricted region D is determined based on the strength of the carrier substrate 1, the size and position of the holding hole region A, etc.

[0027] In step S9, following the determination in step S8 that it is necessary to set the restricted area D, the restricted area D is set to an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1, and the process proceeds to step S10. Here, the restricted area D is set based on any condition, such as whether the strength of the carrier substrate 1 will be reduced by forming the abrasive holding holes 3. In the work carrier 10 of Example 1, as shown by fine dots in Fig. 6, the restricted area D is set to an annular area of ​​a predetermined width along the outside of the edge of the holding hole area A indicated by the dashed line, and an annular area of ​​a predetermined width along the outer periphery 11 of the carrier substrate 1.

[0028] In step S10, following the setting of the restricted area D in step S9, the area obtained by subtracting the holding hole area A and the restricted area D from the entire area of ​​the carrier substrate 1 is set as the possible area E (indicated by a diagonal line slanting upward to the right in FIG. 7), and the process proceeds to step S12. Here, the "possible area E" is the area in the carrier substrate 1 where the abrasive holding holes 3 can be formed. The possible area E is calculated by first calculating the sum of the holding hole area A and the restricted area D (referred to as the "first calculation area"), and then subtracting the first calculation area from the entire area of ​​the carrier substrate 1. Alternatively, the possible area E may be calculated by first calculating the area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1 (referred to as the "second calculation area"), and then subtracting the restricted area D from the second calculation area.

[0029] In step S11, following the determination in step S8 that it is not necessary to set the restricted area D, the area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1 is set as the possible area E, and the process proceeds to step S12.

[0030] In step S12, following the setting of the feasible area E in step S10 or step S11, the area ratio of the feasible area E is calculated, and the process proceeds to step S13. Here, the "area ratio of the feasible area E" refers to the ratio of the area of ​​the feasible area E along the circumferential direction of the carrier substrate 1 to the area of ​​the carrier substrate 1, and is calculated for each radial position of the carrier substrate 1. As shown in FIG. 8, the area ratio of the feasible area E can be represented on a map in which the radial position of the carrier substrate 1 is plotted on the horizontal axis and the area ratio of the feasible area E is plotted on the vertical axis. Note that, regarding the radial position of the carrier substrate 1 on the map, "zero" indicates the position of the center O, and the position increases as the distance from the center O increases, and "MAX" indicates the position of the outer periphery 11 of the carrier substrate 1. The area ratio of the feasible area E is "0%" when the feasible area E does not exist on a ring-shaped line along the circumferential direction of the carrier substrate 1 at a certain radial position, and is "100%" when the feasible area E exists along the entire circumferential direction of the carrier substrate 1. FIG. 8 shows the area ratio of the possible area E (the possible area E set in step S10) when the restricted area D is set.

[0031] In step S13, following the calculation of the area ratio of the possible area E in step S12, a design ratio is calculated based on the area ratio of the abrasive supply area C and the area ratio of the possible area E, and the process proceeds to step S14. Here, the "design ratio" is the smaller area ratio of the area ratio of the abrasive supply area C or the area ratio of the possible area E at the same radial position on the carrier substrate 1. In other words, when the area ratio of the abrasive supply area C is greater than the area ratio of the possible area E at a certain radial position, the design ratio is the value of the area ratio of the possible area E at that radial position. Also, when the area ratio of the abrasive supply area C is less than the area ratio of the possible area E at a certain radial position, the design ratio is the value of the area ratio of the abrasive supply area C at that radial position. Furthermore, when the area ratio of the abrasive supply area C = the area ratio of the possible area E at a certain radial position, the design ratio is the value of the area ratio of the abrasive supply area C and the area ratio of the possible area E at that radial position. In the map shown in FIG. 9, the design ratio is indicated by a solid line, the area ratio of the abrasive supplying region C is indicated by a dashed line, and the area ratio of the possible region E is indicated by a broken line.

[0032] In step S14, following the calculation of the design ratio in step S13, the area ratio of the abrasive holding holes 3 is set based on the calculated design ratio, and the process proceeds to step S15. Here, the "area ratio of the abrasive holding holes 3" refers to the ratio of the area of ​​the abrasive holding holes 3 in the carrier substrate 1 along the circumferential direction of the carrier substrate 1, and is calculated for each radial position on the carrier substrate 1. Here, the area ratio of the abrasive holding holes 3 is desirably set to a value approximately equal to the design ratio, and is set to, for example, an area ratio shown in the map shown in FIG. 10. Note that "approximately the same value" means that the difference between the design ratio and the area ratio of the abrasive holding holes 3 at each radial position is zero, and that this difference is within a predetermined range.

[0033] In step S15, following the setting of the area ratio of the abrasive holding holes 3 in step S14, the abrasive holding holes 3 that satisfy the area ratio set in step S14 are designed inside the possible area E (shown surrounded by a dashed line) as shown by the diagonal lines slanting upward to the right in FIG. 11, and the process proceeds to END. Note that the shape, size, number, position, etc. of the abrasive holding holes 3 can be arbitrarily set as long as the area ratio at each radial position satisfies the area ratio set in step S14 and the abrasive holding holes 3 are designed within the possible area E. For example, a plurality of abrasive holding holes 3 may be formed in the carrier substrate 1 and may be distributed at regular intervals (even intervals) along the circumferential direction of the carrier substrate 1. As a result, for example, as shown in FIG. 11, a plurality of abrasive holding holes 3 (four in FIG. 11) are designed at positions that are point-symmetric with respect to the center O of the carrier substrate 1.

[0034] The operation of the work carrier 10 of the first embodiment will be described below.

[0035] When a workpiece is polished using a surface polishing device equipped with the workpiece carrier 10 of Example 1, it is generally known that the workpiece is easily polished in areas where a large amount of abrasive is supplied, and is not easily polished in areas where a small amount of abrasive is supplied. In addition, roll-off, which results in a lower flatness at the periphery of the workpiece compared to the central portion of the workpiece, is likely to occur.

[0036] On the other hand, during workpiece polishing, the abrasive flows into the abrasive holding holes 3 formed in the work carrier 10, and then flows out from the abrasive holding holes 3. At this time, the work carrier 10 rotates and revolves, so the abrasive holding holes 3 also move in accordance with the movement of the work carrier 10. In other words, the abrasive flows out along the trajectory of the abrasive holding holes 3. For this reason, it is thought that the abrasive is supplied to the polishing surfaces of the upper and lower platens along the trajectory of the abrasive holding holes 3, and by changing the positions at which the abrasive holding holes 3 are formed, it is possible to change the way the abrasive flows.

[0037] In contrast to this, to design the work carrier 10 of Example 1, in the flowchart shown in Fig. 2, first, proceed to step S1, where the entire area of ​​the carrier substrate 1 is set. Next, proceed to step S2, where a holding hole area A, in which the work holding holes 2 are formed, is set in the carrier substrate 1. Here, the holding hole area A is the area where the workpiece is placed during workpiece polishing, and is basically the area where it is desired to supply an abrasive to promote polishing of the workpiece.

[0038] Next, the process proceeds to step S3, where it is determined whether or not it is necessary to set an abrasive suppression region B, which is a region inside the holding hole region A that suppresses the supply of abrasive, within the holding hole region A. Whether or not it is necessary to set an abrasive suppression region B is determined based on the amount of abrasive supplied to the holding hole region A, the distribution of the abrasive supply, the amount of workpiece polished, etc.

[0039] If it is determined that the abrasive-suppression region B needs to be set, the process proceeds to step S4 and then step S5, where the abrasive-suppression region B is set inside the retaining hole region A, and the area obtained by subtracting the abrasive-suppression region B from the retaining hole region A is set as the abrasive-supply region C. If it is determined that the abrasive-suppression region B does not need to be set, the process proceeds to step S6, where the entire retaining hole region A is set as the abrasive-supply region C. In the example shown in Fig. 4, it is determined that the abrasive-suppression region B needs to be set, and the abrasive-supply region C is set as the area obtained by subtracting the abrasive-suppression region B from the retaining hole region A.

[0040] Once the abrasive supplying region C is set, the process proceeds to step S7, where the area ratio of the abrasive supplying region C is calculated.

[0041] Next, the process proceeds to step S8, where it is determined whether or not it is necessary to set a restricted area D, which is an area that restricts the formation of the abrasive holding holes 3, to an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1. Whether or not it is necessary to set the restricted area D is determined based on the strength of the carrier substrate 1, the size and position of the holding hole area A, etc.

[0042] Here, if it is determined that setting of the restricted area D is necessary, the process proceeds to step S9 and step S10 in this order, where the restricted area D is set to an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1, and the area remaining after subtracting the holding hole area A and the restricted area D from the entire area of ​​the carrier substrate 1 is set as the possible area E. Also, if it is determined that setting of the restricted area D is unnecessary, the process proceeds to step S11, where the area remaining after subtracting the holding hole area A from the entire area of ​​the carrier substrate 1 is set as the possible area E. Note that in the example shown in Fig. 7, it is determined that setting of the restricted area D is necessary, and the possible area E is set as the area remaining after subtracting the holding hole area A and the restricted area D from the entire area of ​​the carrier substrate 1.

[0043] Once the possible area E is set, the process proceeds to step S12, where the area ratio of the possible area E is calculated.

[0044] After the area ratios of the abrasive supply region C and the available region E are calculated, the process proceeds to step S13, where the design ratio is calculated. The design ratio is the smaller of the area ratios of the abrasive supply region C and the available region E at the same radial position on the carrier substrate 1. Here, the abrasive supply region C is the region where abrasive supply is desired to promote polishing of the workpiece. In other words, the abrasive supply region C is the region where a relatively large amount of abrasive is required to be supplied, while regions other than the abrasive supply region C are regions where abrasive supply is relatively unnecessary. Therefore, by setting the area ratio of the abrasive holding hole 3 according to the area ratio of the abrasive supply region C, it is possible to form the abrasive holding hole 3 at an appropriate position corresponding to the region where abrasive supply is desired. However, the abrasive holding hole 3 can only be formed in the available region E. Therefore, the area ratio of the abrasive holding hole 3 is limited to the area ratio of the available region E. In other words, the area ratio of the abrasive holding hole 3 cannot be increased at radial positions where the area ratio of the available region E is low.

[0045] In other words, the design ratio indicates a sufficient value of the area ratio of the abrasive holding hole 3 determined by the area ratio of the abrasive supply area C, or the maximum value of the area ratio of the abrasive holding hole 3 determined by the area ratio of the possible area E.

[0046] Once the design ratio is calculated, the process proceeds to step S14 and then step S15, where the area ratio of the abrasive holding hole 3 is set based on the design ratio, and an abrasive holding hole 3 that satisfies the set area ratio is designed within the possible area E.

[0047] In this way, the area ratio of the abrasive holding holes 3 is set based on a design ratio determined from the region where abrasive supply is desired (abrasive supply region C) and the region where abrasive holding holes 3 can be formed (possible region E). This allows the abrasive holding holes 3 to be formed according to the region where abrasive supply is desired (abrasive supply region C), and a design can be made in which abrasive is not actively supplied to regions other than the abrasive supply region C where abrasive supply is relatively unnecessary. As a result, the abrasive holding holes 3 can be designed taking into account the flow of the abrasive, making it possible to supply the abrasive to the required regions of the polishing surfaces of the upper and lower surface plates.

[0048] Furthermore, in the work carrier 10 of Example 1, when an abrasive suppression region B that suppresses the supply of abrasive is set inside the holding hole region A, the region obtained by subtracting the abrasive suppression region B from the holding hole region A is set as the abrasive supply region C. When the abrasive suppression region B is not set inside the holding hole region A, the entire holding hole region is set as the abrasive supply region C.

[0049] For this reason, the abrasive holding holes 3 are designed taking into consideration the distribution of the abrasive supplied to the workpieces held in the workpiece carrier 10. This prevents the abrasive from being unnecessarily supplied to the abrasive suppression area B, prevents the workpieces from being excessively polished, and suppresses the occurrence of roll-off and the like.

[0050] Furthermore, in the work carrier 10 of Example 1, when a restricted area D that restricts the formation of the abrasive holding holes 3 is set in an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1 (an area outside the holding hole area A), the area obtained by subtracting the holding hole area A and the restricted area D from the entire area of ​​the carrier substrate 1 is set as the possible area E. When the restricted area D is not set in the area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1, the area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1 is set as the possible area E.

[0051] For this reason, the abrasive holding holes 3 are designed taking into consideration the strength and realistic design range of the work carrier 10. This ensures the rigidity of the carrier substrate 1 and suppresses bending and distortion of the carrier substrate 1, thereby improving the machining accuracy of the workpiece.

[0052] Furthermore, in the work carrier 10 of Example 1, when the area ratio of the abrasive holding holes 3 is set to a value substantially equal to the design ratio, the abrasive holding holes 3 having a size according to the abrasive supply requirements can be designed to match the size of the available area E. As a result, it becomes possible to appropriately control the flow of the abrasive, and the machining accuracy of the workpiece can be improved.

[0053] Furthermore, in the workpiece carrier 10 of Example 1, a plurality of abrasive holding holes 3 are formed in the carrier substrate 1, and are further distributed at regular intervals (even intervals) along the circumferential direction of the carrier substrate 1. This allows the rigidity of the carrier substrate 1 and distortion and bending that occur in the carrier substrate 1 to be distributed in a balanced manner over the entire carrier substrate 1. This makes it possible to suppress distortion of the carrier substrate 1 during workpiece polishing, and improve the processing accuracy of the workpiece.

[0054] Furthermore, in the workpiece carrier 10 of Example 1, the abrasive holding holes 3 are openings of a size that allow the abrasive supplied from the upper surface plate to the lower surface plate to flow in and hold the abrasive. This allows the abrasive to be supplied to the polishing surfaces of the upper and lower surface plates along the trajectory of the abrasive holding holes 3, and the abrasive can be supplied to the appropriate position.

[0055] The work carrier of the present invention has been described above based on Example 1, but the specific configuration is not limited to this example, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the claims.

[0056] In Example 1, four circular workpiece holding holes 2 and four abrasive holding holes 3 are formed in the carrier substrate 1, but this is not limiting. The number, shape, size, etc. of the workpiece holding holes 2 and abrasive holding holes 3 can be set as desired.

[0057] That is, for example, as in a work carrier 10A of a first modified example shown in Fig. 12(a), one workpiece holding hole 2 and one abrasive holding hole 3 may be formed in a carrier substrate 1. In the example shown in Fig. 12(a), the center O' of the workpiece holding hole 2 is eccentric with respect to the center O of the carrier substrate 1, but the center O' of the workpiece holding hole 2 and the center O of the carrier substrate 1 may also coincide.

[0058] In the work carrier 10A of the first modified example, the holding hole area A, abrasive supply area C, restricted area D, and possible area E are set as shown in Fig. 12(b). In the work carrier 10A of the first modified example, the abrasive suppression area B is not set, and the entire holding hole area A is set as the abrasive supply area C. In Fig. 12(b), the holding hole area A is shown surrounded by a dashed line, the abrasive supply area C is shown with diagonal lines slanting upward to the left, the restricted area D is shown with dots, and the possible area E is shown with diagonal lines slanting upward to the right.

[0059] The area ratio of the abrasive supplying region C, the area ratio of the available region E, and the design ratio in the work carrier 10A of the first modified example are calculated as shown in the map in Fig. 13(a). The area ratio of the abrasive holding holes 3 is shown in the map in Fig. 13(b).

[0060] Furthermore, as in the second modified work carrier 10B shown in Figure 14(a), the shape of each of the four work holding holes 2 may be set to a square, and four abrasive holding holes 3 may be formed in each of the carrier substrates 1, each of which may be set to two different shapes, kite-shaped and triangular, when viewed in a plane.

[0061] In the work carrier 10B of the second modified example, the work holding hole 2 is square, and therefore the work cannot rotate within the work holding hole 2. In this case, the travel speed of the work relative to the upper and lower surface plates generally tends to be higher at positions closer to the outer periphery 11 of the carrier substrate 1 than at positions closer to the center O of the carrier substrate 1. As a result, the part of the work closer to the center O of the carrier substrate 1 is not cut much, and the part closer to the outer periphery 11 of the carrier substrate 1 is cut more, resulting in a deterioration in flatness.

[0062] Therefore, in the work carrier 10B of the second modification, as shown in Fig. 14(b), an abrasive suppression area B (area marked with fine dots) is set inside the holding hole area A (area surrounded by a dashed line). As a result, the abrasive supply area C, where the supply of abrasive is desired, becomes the triangular area (area marked with diagonal lines slanting upward to the left) inside the holding hole area A, which is obtained by subtracting the abrasive suppression area B from the holding hole area A. This makes it possible to suppress the amount of abrasive supplied to a portion of the work (in the work carrier 10B of the second modification, the portion close to the outer portion 11 of the carrier substrate 1), thereby reducing the processing efficiency of a portion of the work and improving the processing accuracy.

[0063] The shape of the abrasive-suppressing region B can be set arbitrarily. Therefore, the abrasive-supplying region C is not limited to the triangular shape shown in FIG. 14(b), but can be set arbitrarily, such as a diamond or a circle. Furthermore, it is also possible to set the abrasive-suppressing region B in the center of the holding hole region A, and set the abrasive-supplying region C on the inner periphery of the holding hole region A.

[0064] Furthermore, as in a work carrier 10C of a third modified example shown in Fig. 15(a), three workpiece holding holes 2 and three abrasive holding holes 3 may be formed in the carrier substrate 1. In the work carrier 10C of the third modified example, the holding hole area A, abrasive-suppression area B, abrasive supply area C, restricted area D, and possible area E are set as shown in Fig. 15(b). In Fig. 15(b), the holding hole area A is shown surrounded by a dashed line, the abrasive-suppression area B is shown with fine dots, the abrasive supply area C is shown with diagonal lines slanting downwards to the left, the restricted area D is shown with coarse dots, and the possible area E is shown with diagonal lines slanting upwards to the right.

[0065] The area ratio of the abrasive supplying region C, the area ratio of the available region E, and the design ratio in the work carrier 10C of the third modified example are calculated as shown in the map in Fig. 16(a). The area ratio of the abrasive holding holes 3 is shown in the map in Fig. 16(b).

[0066] Furthermore, in the work carrier 10C of the third modified example, all three abrasive holding holes 3 are fan-shaped, but this is not limited to this. Since the abrasive holding holes 3 can be designed taking into account the flow of the abrasive by satisfying the design area ratio, the abrasive holding holes 3 may be appropriately modified depending on, for example, the strength of the carrier substrate 1. Specifically, as in the work carrier 10D of the fourth modified example shown in FIG. 17(a), the abrasive holding holes 3 arranged between the workpiece holding holes 2 may be divided into three. Furthermore, as in the work carrier 10E of the fifth modified example shown in FIG. 18(a), the abrasive holding holes 3 arranged between the workpiece holding holes 2 may be divided into two.

[0067] Here, the area ratio of the abrasive holding holes 3 in the work carrier 10D of the fourth modified example is the value shown in the map of Fig. 17(b), and the area ratio of the abrasive holding holes 3 in the work carrier 10E of the fifth modified example is the value shown in the map of Fig. 18(b). Both are different from the area ratio of the abrasive holding holes 3 in the work carrier 10C of the third modified example shown in Fig. 16(b). However, by setting the area ratio of the abrasive holding holes 3 based on the design ratio shown in Fig. 16(a), it becomes possible to supply abrasives to the required areas of the polishing surfaces of the upper and lower surface plates even if the abrasive holding holes 3 are designed to have a shape like the work carrier 10D of the fourth modified example or the work carrier 10E of the fifth modified example.

[0068] Furthermore, the shape of the abrasive holding hole 3 is not limited to these. For example, the shapes shown in Figs. 19(a) to 19(e) may be used. It may have such a shape.

[0069] Furthermore, in the work carrier 10 of Example 1, an abrasive suppression region B is set inside the holding hole region A, and the abrasive supply region C is the region obtained by subtracting the abrasive suppression region B from the holding hole region A. However, it is also possible to set the abrasive supply region C over the entire holding hole region A without setting the abrasive suppression region B. In this case, the area ratio of the abrasive supply region C becomes the value shown in FIG. 20(a), and the design ratio becomes the value shown by the solid line in FIG. 20(b). Then, the design ratio of the abrasive holding hole 3 is set based on the design ratio shown in FIG. 20(b). Even in this case, it is desirable to set the design ratio of the abrasive holding hole 3 to a value approximately the same as the design ratio shown in FIG. 20(b).

[0070] In addition, as in the sixth modified work carrier 10F shown in Figure 21, four fan-shaped first abrasive holding holes 3α and four triangular-shaped second abrasive holding holes 3β may be formed in the carrier substrate 1.

[0071] Furthermore, in the work carrier 10 of Example 1, an example has been shown in which the restricted area D is set to an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1, and the possible area E is set to an area obtained by subtracting the holding hole area A and the restricted area D from the entire area of ​​the carrier substrate 1. However, the restricted area D may not be set, and the possible area E may be set to an area obtained by subtracting the holding hole area A from the entire area of ​​the carrier substrate 1.

[0072] In addition, in the work carrier 10 of Example 1, an example was shown in which the area ratio of the abrasive holding holes 3 was set to a value approximately equal to the design ratio. However, the area ratio of the abrasive holding holes 3 does not necessarily have to be set to a value approximately equal to the design ratio, and the difference between the area ratio of the abrasive holding holes 3 and the design ratio may deviate from a predetermined range.

[0073] In addition, in Example 1, as shown in the flowchart in FIG. 2, an example was given in which the abrasive supply region C is set (step S5 or step S6), the area ratio of the abrasive supply region C is calculated (step S7), the usable region E is set (step S10 or step S11), and the area ratio of the usable region E is calculated (step S12). However, the design procedure for the abrasive holding hole 3 is not limited to the procedure shown in FIG. 2. For example, after the entire area of ​​the carrier substrate 1 is set, the usable region E is set and the area ratio of the usable region E is calculated. Next, after the holding hole region A is set, the abrasive supply region C is set and the area ratio of the abrasive supply region C is calculated. Then, the design ratio is calculated, and the area ratio of the abrasive holding hole 3 is calculated, and the abrasive holding hole 3 is designed. Furthermore, elements within each step may be subdivided or the processing procedures may be interchanged.

[0074] In the work carrier 10 of Example 1, an example was shown in which abrasive holding holes 3 large enough to hold an abrasive were formed in the carrier substrate 1 as second openings, which are openings that do not hold a workpiece. However, the second openings that do not hold a workpiece do not necessarily have to be large enough to hold an abrasive. For example, the second openings may be formed of a large number of mesh-like holes.

[0075] Furthermore, in Example 1, by setting the abrasive supply area C on the inner peripheral edge of the holding hole area A that contacts the outer periphery of the workpiece, it becomes possible to intentionally cause the workpiece to roll off. That is, the workpiece carrier 10 of Example 1 can control the processing accuracy of the workpiece by the carrier design (design of the workpiece carrier 10).

[0076] The work carrier of the present invention can be applied to polishing processes using a polishing pad as well as other polishing and grinding processes such as lapping processes that do not use a polishing pad. [Explanation of symbols]

[0077] 10 Work Career 1 Carrier Board 2 Workpiece holding hole (first opening) 3 Abrasive holding hole (second opening) A Holding hole area B. Abrasive-inhibiting region C. Abrasive supply area D Restricted area E Possible area

Claims

1. A method for designing a work carrier for forming a first opening for holding a workpiece and a second opening for not holding the workpiece in a carrier substrate, comprising: a first step of setting a holding hole region in the carrier substrate where the first opening will be formed; a second step of setting an abrasive supply region, which requires the supply of an abrasive, inside the holding hole region; a third step of calculating an area ratio of the abrasive supply region along the circumferential direction of the carrier substrate for each radial position of the carrier substrate; a fourth step of setting an area obtained by subtracting at least the holding hole area from the entire area of ​​the carrier substrate as a possible area in which the second opening can be formed; a fifth step of calculating a ratio of an area of ​​the available region along a circumferential direction of the carrier substrate for each radial position of the carrier substrate; a sixth step of comparing the area ratio of the abrasive supply region and the area ratio of the available region for each radial position of the carrier substrate, and setting the smaller one as a design ratio; a seventh step of setting an area ratio of the second opening along the circumferential direction of the carrier substrate for each radial position of the carrier substrate based on the design ratio; an eighth step of designing the second opening portion, which satisfies the area ratio set in the seventh step, inside the possible area; A method for designing a work carrier, comprising:

2. In the method for designing a work carrier according to claim 1, In the seventh step, a value substantially equal to the design ratio is set as a ratio of the area of ​​the second opening along the circumferential direction of the carrier substrate. A method for designing a work carrier characterized by the above.

3. In the method for designing a work carrier according to claim 1 or 2, In the second step, it is determined whether or not an abrasive suppression region for suppressing the supply of the abrasive is required to be set inside the holding hole region; If it is determined that the setting of the abrasive-suppressing region is necessary, the abrasive-suppressing region is set inside the holding hole region, and the region obtained by subtracting the abrasive-suppressing region from the holding hole region is set as the abrasive-supplying region; If it is determined that the abrasive suppression region does not need to be set, the entire holding hole region is set as the abrasive supply region. A method for designing a work carrier.

4. In the method for designing a work carrier according to claim 1 or 2, In the fourth step, it is determined whether or not a restriction region that restricts formation of the second opening in the carrier substrate needs to be set; When it is determined that the setting of the restricted area is necessary, the area obtained by subtracting the holding hole area and the restricted area from the entire area of ​​the carrier substrate is set as the possible area; If it is determined that the setting of the restricted area is unnecessary, the area obtained by subtracting the holding hole area from the entire area of ​​the carrier substrate is set as the possible area. A method for designing a work carrier.

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