Work carrier

Abstract

[Project] To provide a work carrier with abrasive retention holes designed considering the flow direction of the abrasive. [Solution] In a work carrier (10) in which a work holding hole (2) and an abrasive holding hole (3) are formed on a carrier substrate (1), a holding hole area (A), an abrasive supply area (C), and a possible area (E) are set on the carrier substrate (1). The ratio of the area of ​​the abrasive supply area (C) along the circumferential direction of the carrier substrate (1) is set as the area ratio of the abrasive supply area (C), and the ratio of the area of ​​the possible area (E) along the circumferential direction of the carrier substrate (1) is set as the area ratio of the possible area (E). Among the area ratio of the abrasive supply area (C) and the area ratio of the possible area (E), the smaller area ratio at the same radial position of the carrier substrate (1) is set as the design ratio. Furthermore, the abrasive holding hole (3) is formed in the possible area (E) at each radial position of the carrier substrate (1), with the area ratio obtained along the circumferential direction of the carrier substrate (1) being set based on the design ratio.

Description

Technology Field

[0001] The present invention relates to a workpiece carrier used for holding a workpiece when the workpiece is polished by a polishing device. Background Technology

[0002] Conventionally, a work carrier is known in which a first opening for holding a workpiece and a second opening for passing an abrasive without holding a workpiece (holding the abrasive) are formed on a carrier substrate, as a work carrier used for holding a workpiece when grinding a workpiece in a grinding device (see, for example, Patent Documents 1 and 2). Prior art literature

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-22542 [Patent Document 2] Japanese Patent Publication No. 2018-47552 The problem to be solved

[0004] However, it has been observed that in work carriers, if the design, such as the size or arrangement of the second opening, differs, the machining precision of the workpiece tends to vary. In other words, it can be assumed that the flow direction of the abrasive supplied between the polishing surface of the polishing device, the work carrier, and the workpiece changes depending on the size or 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 influence of the abrasive flow direction on the machining precision of the workpiece has not been considered.

[0005] The present invention, based on the above problem, aims to provide a work carrier designed with a second opening that takes into account the flow direction of the abrasive. means of solving the problem

[0006] To achieve the above objective, the present invention relates to a work carrier having a first opening for holding a work and a second opening for not holding a work formed in a carrier substrate. In the carrier substrate, a holding hole area in which the first opening is formed, an abrasive supply area in which an abrasive is desired to be supplied as an inner portion of the holding hole area, and a possible area in which the second opening can be formed are provided. Furthermore, for each radial position of the carrier substrate, the ratio of the area of ​​the abrasive supply area obtained according to the circumferential direction of the carrier substrate is defined as the area ratio of the abrasive supply area, and for each radial position of the carrier substrate, the ratio of the area of ​​the possible area obtained according to the circumferential direction of the carrier substrate is defined as the area ratio of the possible area. Moreover, among the area ratio of the abrasive supply area and the area ratio of the possible area, the smaller area ratio at the same radial position of the carrier substrate is defined as the design ratio. In addition, the second opening is characterized by being formed in the possible area, wherein the ratio of the area obtained according to the circumferential direction of the carrier substrate at each radial position of the carrier substrate is set based on the design ratio. Effects of the invention

[0007] Accordingly, a work carrier can be provided with a second opening designed to take into account the flow direction of the abrasive. Brief explanation of the drawing

[0008] [Fig. 1] This is a plan view showing the work carrier of Example 1. [Fig. 2] This is a flowchart showing the flow of the design procedure for the abrasive retaining hole of Example 1. [Fig. 3] This is an explanatory diagram showing the retaining hole area set in the work carrier of Example 1. [Fig. 4] This is an explanatory diagram showing the abrasive suppression area and the abrasive supply area set in the work carrier of Example 1. [Fig. 5] This is a map showing the area ratio of the abrasive supply area of ​​Example 1. [Fig. 6] This is an explanatory diagram showing the restricted area set on the work carrier of Example 1. [Fig. 7] This is an explanatory diagram showing the possible area set on the work carrier of Example 1. [Fig. 8] This is a map showing the area ratio of the possible region of Example 1. [Fig. 9] This is a map showing the design ratio of Example 1. [Fig. 10] This is a map showing the area ratio of the abrasive retention holes in Example 1. [Fig. 11] This is an explanatory diagram showing an example of the design of the abrasive retention hole of Example 1. [Fig. 12] (a) is a plan view showing a work carrier of the first modified example, and (b) is an explanatory diagram showing a retaining hole area, abrasive supply area, a limiting area, and a possible area set in the work carrier of the first modified example. [Fig. 13] (a) 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 first variant example, and (b) is a map showing the area ratio of the abrasive retaining hole of the first variant example. [Fig. 14] (a) is a plan view showing the work carrier of the second modified example, and (b) is an explanatory diagram showing the retaining hole area, abrasive suppression area, abrasive supply area, restriction area, and possibility area set in the work carrier of the second modified example. [Fig. 15] (a) is a plan view showing the work carrier of the third variant example, and (b) is an explanatory diagram showing the retaining hole area, abrasive suppression area, abrasive supply area, restriction area, and possibility area set in the work carrier of the third variant example. [Fig. 16] (a) 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 third variant example, and (b) is a map showing the area ratio of the abrasive retaining hole of the third variant example. [Fig. 17] (a) is a plan view showing the work carrier of the fourth variant example, and (b) is a map showing the area ratio of the abrasive retaining hole of the fourth variant example. [Fig. 18] (a) is a plan view showing the work carrier of the fifth variant example, and (b) is a map showing the area ratio of the abrasive retaining hole of the fifth variant example. [Fig. 19] (a) to (e) are plan views of a work carrier showing examples of deformation of the abrasive retaining hole. [Fig. 20] (a) is a map showing the area ratio of the abrasive supply area of ​​the work carrier of the 6th variant 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 6th variant example. [Fig. 21] This is a plan view showing the work carrier of the 6th variant example. Specific details for implementing the invention

[0009] Hereinafter, a form for implementing the work carrier of the present invention will be described based on Example 1 illustrated in the drawings.

[0010] The work carrier (10) of Example 1 is mounted on a flat grinding device that grinds both sides or one side of a thin plate-shaped work. For example, the flat grinding device that grinds both sides of the work has an upper platen and a lower platen, which are platens, a sun gear positioned at the center of the upper platen and the lower platen, and an internal gear positioned at the outer circumference of the upper platen and the lower platen. The upper platen, the lower platen, the sun gear, and the internal gear are each freely rotatable. In addition, during the grinding of the work, an abrasive is supplied between the upper and lower platens through a hole penetrating the upper platen.

[0011] And, the work carrier (10) shown in FIG. 1 is placed between the upper platen and the lower platen of the flat polishing device.

[0012] The work carrier (10) has a main body formed by a disc-shaped carrier substrate (1). The carrier substrate (1) has a plurality of work retaining holes (2) (four circular holes in FIG. 1) and a plurality of abrasive retaining holes (3) (four holes in FIG. 1) drilled therein.

[0013] The carrier substrate (1) is formed by cutting a plate material, such as a metal plate, a resin plate, or ceramics, into a disc shape. As the metal plate, stainless steel (SUS), high-carbon chromium bearing steel, carbon tool steel (SK steel), high-speed tool steel, alloy tool steel, high-tensile strength steel, titanium, etc., can be used. In addition, as the resin plate, polyamide (PA), polyacetal (POM), polyvinyl chloride (PVC), polycarbonate (PC), polyimide (PI), polyamideimide (PAI), epoxy (EP), and fiber reinforced resin (FRP) in which fibers such as glass fiber, carbon fiber, or aramid fiber are composited with the resin can be used. Additionally, when the carrier substrate (1) is formed as a metal plate, although not illustrated, a resin insert may be installed along the inner surface (21) of the work holding hole (2) as needed.

[0014] The work carrier (10) has a tooth portion installed on the outer edge (11) of the carrier substrate (1) that meshes with the sun gear and internal gear of the flat polishing device. The work carrier (10) rotates and revolves by the rotation of the sun gear and internal gear. Additionally, as the work carrier (10) rotates and revolves, both sides of the work placed within the work holding hole (2) of the work carrier (10) are polished by the polishing surfaces of the upper platen and the lower platen.

[0015] The work holding hole (2) penetrates the carrier substrate (1) in the thickness direction and is a first opening in which a work is placed inside and the work is held. The work holding hole (2) is formed in the holding hole region (A) (see FIG. 3) described later, which is set within the carrier substrate (1), and therein, four work holding holes (2) are arranged in a position that is point-symmetric with the center (O) of the carrier substrate (1) as the center of symmetry.

[0016] The abrasive retaining hole (3) penetrates the carrier substrate (1) in the thickness direction and is a second opening that retains the abrasive. The abrasive retaining hole (3) is an opening of a size capable of retaining the abrasive supplied from the upper platen toward the lower platen during the polishing of the work. The abrasive retained in the abrasive retaining hole (3) flows out from the abrasive retaining hole (3) during the polishing of the work and is supplied to the polishing surfaces of the upper platen and the lower platen. Additionally, the work is not placed inside the abrasive retaining hole (3), and the abrasive retaining hole (3) becomes an opening that does not retain the work formed in the carrier substrate (1).

[0017] The abrasive retaining holes (3) are formed in the possible area (E) described later (see FIG. 7) set within the carrier substrate (1). Here, four abrasive retaining holes (3) are arranged in a position that is point-symmetric with the center (O) of the carrier substrate (1) as the center of symmetry, and are aligned at a constant interval (equal interval) along the circumferential direction of the carrier substrate (1). In addition, the abrasive retaining holes (3) of Example 1 are arranged between adjacent work retaining holes (2) as shown in FIG. 1, and when the work carrier (10) is viewed in a planar view, they exhibit a fan-shaped form that gradually widens as they face outward in the radial direction of the carrier substrate (1).

[0018] FIG. 2 is a flowchart showing the flow of the design procedure for the abrasive retaining hole (3) of Example 1. Each step of the flowchart in FIG. 2 will be described below. Additionally, the design of the abrasive retaining hole (3) may be performed automatically using a computer or the like, or may be performed by a person.

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

[0020] In step (S2), following the setting of the entire 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 an area where a work holding hole (2) is formed in the carrier substrate (1), and in FIG. 3, it is indicated by an upward-facing diagonal line. The holding hole area (A) is arbitrarily set based on the size or shape of the carrier substrate (1), the size or 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 it is necessary to set an abrasive suppression area (B) inside the retaining hole area (A). If YES (setting of the abrasive suppression area (B) is necessary), the process proceeds to step (S4), and if NO (setting of the abrasive suppression area (B) is unnecessary), the process proceeds to step (S6). Here, the "abrasive suppression area (B)" is an area that suppresses the supply of abrasive within the retaining hole area (A). Whether it is necessary to set the abrasive suppression area (B) is determined based on the amount of abrasive supplied to the retaining hole area (A), the distribution of the abrasive supply, the amount of abrasive on the workpiece, etc.

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

[0023] In step (S5), following the setting of the abrasive suppression area (B) in step (S4), the area obtained by subtracting the abrasive suppression area (B) from the retaining hole area (A) is set as the abrasive supply area (C) (indicated by a coarse dot in FIG. 4), and the process proceeds to step (S7). Here, the "abrasive supply area (C)" is an area where the supply of abrasive is desired within the retaining hole area (A). That is, the abrasive supply area (C) is an area within the retaining hole area (A) where the supply of abrasive is required.

[0024] In step (S6), following the determination that the setting of the abrasive suppression area (B) in step (S3) is unnecessary, the entire area of ​​the retaining hole area (A) is set as the abrasive supply area (C), and the process proceeds to step (S7).

[0025] In step (S7), following the setting of the abrasive supply area (C) in step (S5) or step (S6), the area ratio of the abrasive supply area (C) is calculated, and the process proceeds to step (S8). Here, the "area ratio of the abrasive supply area (C)" is the ratio of the area occupied by the abrasive supply area (C) in 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). The area ratio of the abrasive supply area (C) can be displayed on a map in which the radial position of the carrier substrate (1) is taken as the horizontal axis and the area ratio of the abrasive supply area (C) is taken as the vertical axis, as shown in FIG. 5. In the radial position of the carrier substrate (1) on the map, "Zero (0)" represents the position of the center (O), and increases as it moves away from the center (O), and "MAX" represents the position of the outer part (11) of the carrier substrate (1). Additionally, the area ratio of the abrasive supply area (C) becomes "zero (0)%" when the abrasive supply area (C) does not exist on the annular line along the circumferential direction of the carrier substrate (1) at any radial position. Additionally, the area ratio of the abrasive supply area (C) becomes "100%" when the abrasive supply area (C) exists along the entire circumference along the circumferential direction of the carrier substrate (1) at any radial position. Furthermore, FIG. 5 shows the area ratio of the abrasive supply area (C) (the abrasive supply area (C) set in step (S5)) when the abrasive suppression area (B) is set.

[0026] In step (S8), following the calculation of the area ratio of the abrasive supply area (C) in step (S7), it is determined whether the restriction area (D) needs to be set. If YES (the restriction area (D) needs to be set), the process proceeds to step (S9), and if NO (the restriction area (D) does not need to be set), the process proceeds to step (S11). Here, the “restriction area (D)” is an area where the formation of the abrasive retaining hole (3) is restricted in the area obtained by subtracting the retaining hole area (A) from the entire carrier substrate (1) (an area outside the retaining hole area (A)). Whether the restriction area (D) needs to be set is determined based on the strength of the carrier substrate (1), the size or location of the retaining hole area (A), etc.

[0027] In step (S9), following the determination that the restriction area (D) in step (S8) needs to be set, the restriction area (D) is set in the area obtained by subtracting the retaining hole area (A) from the entire carrier substrate (1), and the process proceeds to step (S10). Here, the restriction area (D) is set based on arbitrary conditions, such as the strength of the carrier substrate (1) being reduced by forming the abrasive retaining hole (3). In the work carrier (10) of Example 1, as shown by fine dots in FIG. 6, it is set as an annular area of ​​a predetermined width along the outer edge of the retaining hole area (A) indicated by the dashed line and an annular area of ​​a predetermined width along the outer shape (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 retaining hole area (A) and the restricted area (D) from the entire carrier substrate (1) is set as the possible area (E) (indicated by an upward-sloping diagonal line in FIG. 7), and the process proceeds to step (S12). Here, the "possible area (E)" is an area where an abrasive retaining hole (3) can be formed in the carrier substrate (1). Furthermore, the possible area (E) is calculated by first calculating the sum of the retaining 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 carrier substrate (1). Additionally, the possible area (E) may be calculated by first subtracting the retaining hole area (A) from the entire 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 that setting the restricted area (D) in step (S8) is unnecessary, the area obtained by subtracting the retaining hole area (A) from the entire 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 possible area (E) in step (S10) or step (S11), the area ratio of the possible area (E) is calculated, and the process proceeds to step (S13). Here, the "area ratio of the possible area (E)" is the ratio of the area occupied by the possible area (E) in 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). The area ratio of the possible area (E) can be displayed on a map in which the radial position of the carrier substrate (1) is taken as the horizontal axis and the area ratio of the possible area (E) is taken as the vertical axis, as shown in FIG. 8. Additionally, regarding the radial position of the carrier substrate (1) in the map, "Zero (0)" represents the position of the center (O), and increases as it moves away from the center (O), and "MAX" represents the position of the outer part (11) of the carrier substrate (1). Additionally, the area ratio of the possible region (E) is "zero (0)%" when the possible region (E) does not exist on the circular line along the circumferential direction of the carrier substrate (1) at any radial position, and "100%" when the possible region (E) exists over the entire circumference along the circumferential direction of the carrier substrate (1). FIG. 8 shows the area ratio of the possible region (E) (the possible region (E) set in step (S10)) when the restricted region (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 value of the smaller area ratio between the area ratio of the abrasive supply area (C) and the area ratio of the possible area (E) at the same radial position of the carrier substrate (1). That is, 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 takes the value of the area ratio of the possible area (E) at the said radial position. Additionally, 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 takes the value of the area ratio of the abrasive supply area (C) at the said radial position. In addition, the design ratio takes the values ​​of the area ratio of the abrasive supply area (C) and the area ratio of the possible area (E) at a certain radial position, where the area ratio of the abrasive supply area (C) equals the area ratio of the possible area (E). In the map shown in FIG. 9, the design ratio is represented by a solid line, the area ratio of the abrasive supply area (C) is represented by a dotted line, and the area ratio of the possible area (E) is represented by a dashed line.

[0032] In step (S14), following the calculation of the design ratio in step (S13), the process proceeds to step (S15). Here, the "area ratio of the abrasive retaining hole (3)" is the ratio of the area occupied by the abrasive retaining hole (3) in 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). Here, it is preferable that the area ratio of the abrasive retaining hole (3) be set to a value approximately equal to the design ratio, and for example, it is set to the area ratio shown in the map illustrated in FIG. 10. Additionally, "approximately equal value" means a state in which the difference between the design ratio at each radial position and the area ratio of the abrasive retaining hole (3) is zero (0), and in addition, the difference falls within a predetermined range.

[0033] In step (S15), following the setting of the area ratio of the abrasive retaining hole (3) in step (S14), the abrasive retaining hole (3) satisfying the area ratio set in step (S14) is designed inside the possible area (E) (indicated by a dashed line), as shown by the upward-facing diagonal line in FIG. 11, and the process proceeds to the end. Additionally, the shape, size, number, position, etc. of the abrasive retaining hole (3) can be arbitrarily set as long as the area ratio at each radial position satisfies the area ratio set in step (S14) and is designed within the possible area (E). For example, the abrasive retaining hole (3) may be formed in multiple places on the carrier substrate (1) and may also be distributed at regular intervals (equal intervals) along the circumferential direction of the carrier substrate (1). As a result, for example, as shown in FIG. 11, a plurality (four in FIG. 11) of abrasive retaining holes (3) are designed in a position that is point-symmetric with the center (O) of the carrier substrate (1) as the center of symmetry.

[0034] The operation of the work carrier (10) of Example 1 is explained below.

[0035] It is known that when polishing a workpiece using a flat polishing device equipped with the workpiece carrier (10) of Example 1, generally, the workpiece is easily polished in areas with a large supply of abrasive, and difficult to polish in areas with a small supply of abrasive. Additionally, roll-off, which is less flat than the center of the workpiece, is likely to occur in the outer periphery of the workpiece.

[0036] Meanwhile, during work polishing, the abrasive is introduced into the abrasive retaining hole (3) formed in the work carrier (10) and then flows out from the abrasive retaining hole (3). At this time, as the work carrier (10) rotates and revolves, the abrasive retaining hole (3) also moves according to the movement of the work carrier (10). That is, the abrasive flows out along the trajectory of the abrasive retaining hole (3). Because of this, it can be assumed that the abrasive is supplied to the polishing surfaces of the upper platen and the lower platen along the trajectory of the abrasive retaining hole (3), and by changing the position in which the abrasive retaining hole (3) is formed, it becomes possible to change the direction of flow of the abrasive.

[0037] In this regard, to design the work carrier (10) of Example 1, in the flowchart shown in FIG. 2, first, proceed to step (S1) to set the entire area of ​​the carrier substrate (1). Next, proceed to step (S2) to set the retaining hole area (A) that forms the work retaining hole (2) within the carrier substrate (1). Here, the retaining hole area (A) is an area where the work is placed during work polishing, and is an area where an abrasive is basically to be supplied to promote the polishing of the work.

[0038] Next, proceed to step (S3), and determine whether it is necessary to set an abrasive suppression area (B), which is an area that suppresses the supply of abrasive inside the retaining hole area (A), within the retaining hole area (A). Additionally, whether it is necessary to set an abrasive suppression area (B) is determined based on the amount of abrasive supplied to the retaining hole area (A), the supply distribution of abrasive, the amount of abrasive on the workpiece, etc.

[0039] Here, if it is determined that the setting of the abrasive suppression area (B) is necessary, the process proceeds in the order of step (S4) and step (S5), the abrasive suppression area (B) is set inside the retaining hole area (A), and the area obtained by subtracting the abrasive suppression area (B) from the retaining hole area (A) is set as the abrasive supply area (C). Additionally, if it is determined that the setting of the abrasive suppression area (B) is unnecessary, the process proceeds to step (S6), and the entire area of ​​the retaining hole area (A) is set as the abrasive supply area (C). Furthermore, in the example shown in FIG. 4, it is determined that the setting of the abrasive suppression area (B) is necessary, so the abrasive supply area (C) is the area obtained by subtracting the abrasive suppression area (B) from the retaining hole area (A).

[0040] Then, when the abrasive supply area (C) is set, the process continues to step (S7) to calculate the area ratio of the abrasive supply area (C).

[0041] Next, proceed to step (S8) to determine whether it is necessary to set a limiting area (D), which is an area that limits the formation of the abrasive retaining hole (3), in an area obtained by subtracting the retaining hole area (A) from the entire carrier substrate (1). Additionally, whether it is necessary to set the limiting area (D) is determined based on the strength of the carrier substrate (1), the size or location of the retaining hole area (A), etc.

[0042] Here, if it is determined that setting the restricted area (D) is necessary, the process proceeds in the order of step (S9) and step (S10), so that the restricted area (D) is set in the area obtained by subtracting the retaining hole area (A) from the entire area of ​​the carrier substrate (1), and the area remaining after subtracting the retaining hole area (A) and the restricted area (D) from the entire area of ​​the carrier substrate (1) is set as the available area (E). Additionally, if it is determined that setting the restricted area (D) is unnecessary, the process proceeds to step (S11), so that the area remaining after subtracting the retaining hole area (A) from the entire area of ​​the carrier substrate (1) is set as the available area (E). Furthermore, in the example shown in FIG. 7, it is determined that setting the restricted area (D) is necessary, so the available area (E) is the area remaining after subtracting the retaining hole area (A) and the restricted area (D) from the entire area of ​​the carrier substrate (1).

[0043] Then, when the possible area (E) is set, the process continues to step (S12) to calculate the area ratio of the possible area (E).

[0044] Furthermore, when the area ratios of the abrasive supply area (C) and the possible area (E) are each calculated, the process proceeds to step (S13) to calculate the design ratio. The design ratio is the ratio of the smaller area between the area ratio of the abrasive supply area (C) and the area ratio of the possible area (E) at the same radial position of the carrier substrate (1). Here, the abrasive supply area (C) is an area where the supply of abrasive is desired to promote the polishing of the workpiece. In other words, the abrasive supply area (C) is an area where there is a demand to supply a relatively large amount of abrasive, and the area other than the abrasive supply area (C) is an area where the supply of abrasive is relatively unnecessary. Therefore, by setting the area ratio of the abrasive holding hole (3) according to the area ratio of the abrasive supply area (C), it becomes possible to form the abrasive holding hole (3) at an appropriate location corresponding to the area where the supply of abrasive is desired. However, the abrasive holding hole (3) can only be formed in the possible area (E). For this reason, the area ratio of the abrasive retaining hole (3) is limited to the area ratio of the possible area (E). That is, at a radial position where the area ratio of the possible area (E) is low, the area ratio of the abrasive retaining hole (3) cannot be increased.

[0045] That is, the design ratio represents a sufficient value of the area ratio of the abrasive retaining hole (3) determined by the area ratio of the abrasive supply area (C), or a maximum value of the area ratio of the abrasive retaining hole (3) determined by the area ratio of the possible area (E).

[0046] Once the design ratio is calculated, the process continues in the order of step (S14) and step (S15), and the area ratio of the abrasive retaining hole (3) is set based on the design ratio, and the abrasive retaining hole (3) satisfying the set area ratio is designed within the possible area (E).

[0047] In this way, the area ratio of the abrasive holding hole (3) is set based on a design ratio determined from the area where abrasive supply is desired (abrasive supply area (C)) and the area where abrasive holding hole (3) can be formed (possible area (E)). Accordingly, the abrasive holding hole (3) can be formed according to the area where abrasive supply is desired (abrasive supply area (C)), and the design can be such that abrasive supply is not actively maintained in the area other than the abrasive supply area (C), which is an area where abrasive supply is relatively unnecessary. As a result, an abrasive holding hole (3) can be designed considering the flow direction of the abrasive, making it possible to supply abrasive to the necessary area of ​​the polishing surface of the upper and lower plates.

[0048] In addition, in the work carrier (10) of Example 1, if an abrasive suppression area (B) that suppresses the supply of abrasive is set inside the retaining hole area (A), the area obtained by subtracting the abrasive suppression area (B) from the retaining hole area (A) is set as an abrasive supply area (C). And, if an abrasive suppression area (B) is not set inside the retaining hole area (A), the entire area of ​​the retaining hole area is set as an abrasive supply area (C).

[0049] For this reason, the abrasive retaining hole (3) is designed to take into account the distribution of abrasive supplied to the workpiece held in the workpiece carrier (10). Accordingly, the supply of abrasive to the abrasive suppression area (B) is suppressed, and the workpiece is suppressed from being excessively polished, thereby suppressing the occurrence of roll-off, etc.

[0050] In addition, in the work carrier (10) of Example 1, if a restricted area (D) that limits the formation of an abrasive retaining hole (3) is set in an area (an outer area of ​​the retaining hole area (A)) that subtracts the retaining hole area (A) from the entire area of ​​the carrier substrate (1), then the area subtracted from the retaining hole area (A) and the restricted area (D) is set as a possible area (E). And, if a restricted area (D) is not set in an area subtracted from the retaining hole area (A) from the entire area of ​​the carrier substrate (1), then the area subtracted from the retaining hole area (A) from the entire area of ​​the carrier substrate (1) is set as a possible area (E).

[0051] For this reason, the abrasive retaining hole (3) is designed considering the strength of the work carrier (10) and a realistic design area. Accordingly, the rigidity of the carrier substrate (1) is ensured, and distortion or warping of the carrier substrate (1) is suppressed, thereby improving the processing precision of the work.

[0052] In addition, in the work carrier (10) of Example 1, when the area ratio of the abrasive retaining hole (3) is set to a value approximately equal to the design ratio, the abrasive retaining hole (3) of the size according to the abrasive supply requirement can be designed to match the size of the possible area (E). As a result, it is possible to properly control the flow of the abrasive, thereby improving the processing precision of the work.

[0053] In addition, in the work carrier (10) of Example 1, a plurality of abrasive retaining 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). From this, the rigidity of the carrier substrate (1) and the twisting or bending that occurs in the carrier substrate (1) can be distributed evenly throughout the carrier substrate (1). Because of this, the twisting of the carrier substrate (1) during work polishing can be suppressed, thereby improving the processing precision of the work.

[0054] In addition, in the work carrier (10) of Example 1, the abrasive retaining hole (3) is an opening of a size that allows abrasive supplied from the upper platen toward the lower platen during the polishing of the work, and retains the abrasive. Accordingly, abrasive can be supplied to the polishing surfaces of the upper platen and the lower platen along the trajectory of the abrasive retaining hole (3), thereby allowing abrasive to be supplied to appropriate locations.

[0055] Although the work carrier of the present invention has been described above based on Example 1, the specific configuration is not limited to this example, and changes or additions to the design are permitted within the scope of not departing from the essence of the invention according to each claim of the patent claims.

[0056] In Example 1, an example was shown in which four circular workpiece holding holes (2) and four abrasive holding holes (3) are formed on a carrier substrate (1), but this is not limited thereto. The number, shape, size, etc. of the workpiece holding holes (2) and abrasive holding holes (3) can be arbitrarily set.

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

[0058] Additionally, in the work carrier (10A) of the first modified example, the retaining hole area (A), the abrasive supply area (C), the restriction area (D), and the possibility area (E) are each set as shown in FIG. 12 (b). Additionally, in the work carrier (10A) of the first modified example, the abrasive suppression area (B) is not set, and the entire area of ​​the retaining hole area (A) is set as the abrasive supply area (C). In FIG. 12 (b), the retaining hole area (A) is enclosed by a dashed line, the abrasive supply area (C) is indicated by an upward-left diagonal line, the restriction area (D) is indicated by a dot, and the possibility area (E) is indicated by an upward-right diagonal line.

[0059] In addition, the area ratio of the abrasive supply area (C), the area ratio of the possible area (E), and the design ratio in the work carrier (10A) of the first variation example are calculated as shown in the map illustrated in FIG. 13 (a), respectively. And, the area ratio of the abrasive retaining hole (3) is shown in the map illustrated in FIG. 13 (b).

[0060] In addition, as with the work carrier (10B) of the second modified example shown in FIG. 14 (a), the shape of each of the four work holding holes (2) is set to a square, and four abrasive holding holes (3) are formed on the carrier substrate (1) in two types of shapes, such as kite shape and triangle, in a planar view.

[0061] Additionally, in the work carrier (10B) of the second variant example, the work holding hole (2) is square, so the work cannot rotate within the work holding hole (2). In this case, generally, at a position close to the outer shape (11) of the carrier substrate (1), the travel speed of the work relative to the upper platen and the lower platen tends to increase compared to a position close to the center (O) of the carrier substrate (1). Accordingly, the part of the work close to the center (O) of the carrier substrate (1) is not cut much, and the part close to the outer shape (11) of the carrier substrate (1) is cut significantly, and the flatness deteriorates.

[0062] Accordingly, in the work carrier (10B) of the second modified example, as shown in FIG. 14 (b), an abrasive suppression area (B) (an area marked with fine dots) is set inside the retaining hole area (A) (an area enclosed by dashed lines). As a result, the abrasive supply area (C) where abrasive supply is desired becomes the triangular area (an area marked with an upward-left diagonal line) inside the retaining hole area (A) by subtracting the abrasive suppression area (B) from the retaining hole area (A). Accordingly, the amount of abrasive supplied to a part of the work (in the work carrier (10B) of the second modified example, a part close to the outer shape (11) of the carrier substrate (1)) can be suppressed, and the processing efficiency of the part of the work can be lowered to improve processing precision.

[0063] Additionally, the shape of the abrasive suppression area (B) can be arbitrarily set. Therefore, the abrasive supply area (C) is not limited to the triangular shape shown in Fig. 14 (b), but can be set to any shape such as a diamond shape or a circular shape. Furthermore, it is also possible to set the abrasive suppression area (B) at the center of the retaining hole area (A) and set the abrasive supply area (C) at the inner periphery of the retaining hole area (A).

[0064] In addition, as in the work carrier (10C) of the third modified example shown in FIG. 15 (a), three work 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), the abrasive suppression area (B), the abrasive supply area (C), the restriction area (D), and the possibility area (E) are each set as shown in FIG. 15 (b). Additionally, in FIG. 15 (b), the holding hole area (A) is enclosed by a dashed line, the abrasive suppression area (B) is indicated by a fine dot, the abrasive supply area (C) is indicated by an upward-left diagonal line, the restriction area (D) is indicated by a coarse dot, and the possibility area (E) is indicated by an upward-right diagonal line.

[0065] In addition, the area ratio of the abrasive supply area (C), the area ratio of the possible area (E), and the design ratio in the work carrier (10C) of the third variation example are calculated as shown in the map illustrated in FIG. 16 (a), respectively. And, the area ratio of the abrasive retaining hole (3) is shown in the map illustrated in FIG. 16 (b).

[0066] In addition, in the work carrier (10C) of the third variant example, all three abrasive retaining holes (3) have a fan-shaped form, but this is not limited thereto. Since the abrasive retaining holes (3) can be designed to consider the flow direction of the abrasive by satisfying the area ratio of the design ratio, for example, the abrasive retaining holes (3) may be appropriately modified according to the strength of the carrier substrate (1). Specifically, as in the work carrier (10D) of the fourth variant example shown in FIG. 17 (a), the abrasive retaining holes (3) placed between the work retaining holes (2) may be divided into three. Also, as in the work carrier (10E) of the fifth variant example shown in FIG. 18 (a), the abrasive retaining holes (3) placed between the work retaining holes (2) may be divided into two.

[0067] Here, the area ratio of the abrasive retaining hole (3) in the work carrier (10D) of the fourth variant example is the value shown in the map of FIG. 17 (b), and the area ratio of the abrasive retaining hole (3) in the work carrier (10E) of the fifth variant example is the value shown in the map of FIG. 18 (b). In either case, it is different from the area ratio of the abrasive retaining hole (3) in the work carrier (10C) of the third variant example shown in FIG. 16 (b). However, by setting the area ratio of the abrasive retaining hole (3) based on the design ratio shown in FIG. 16 (a), it becomes possible to supply abrasive to the necessary area of ​​the polishing surface of the upper and lower plates even if the abrasive retaining hole (3) is designed in the same shape as the work carrier (10D) of the fourth variant example or the work carrier (10E) of the fifth variant example.

[0068] Furthermore, the shape of the abrasive retaining hole (3) is not limited to these, and may be, for example, the shape shown in (a) to (e) of FIG. 19.

[0069] In addition, in the work carrier (10) of Example 1, an abrasive suppression area (B) is set inside the retaining hole area (A), and an abrasive supply area (C) is set as the area obtained by subtracting the abrasive suppression area (B) from the retaining hole area (A). However, it is acceptable to set the abrasive supply area (C) as the entire retaining hole area (A) without setting the abrasive suppression area (B). In this case, the area ratio of the abrasive supply area (C) is the value shown in FIG. 20 (a), and the design ratio is the value indicated by the solid line in FIG. 20 (b). Then, the design ratio of the abrasive retaining hole (3) is set based on the design ratio shown in FIG. 20 (b). Furthermore, in this case as well, it is preferable to set the design ratio of the abrasive retaining hole (3) to a value approximately equal to the design ratio shown in FIG. 20 (b).

[0070] In addition, as with the work carrier (10F) of the sixth modified example shown in FIG. 21, four first abrasive retaining holes (3α) in a fan shape and four second abrasive retaining holes (3β) in a triangular shape may be formed on the carrier substrate (1).

[0071] In addition, in the work carrier (10) of Example 1, a restricted area (D) is set in the area obtained by subtracting the retaining hole area (A) from the entire area of ​​the carrier substrate (1), and a possible area (E) is set in the area obtained by subtracting the retaining hole area (A) and the restricted area (D) from the entire area of ​​the carrier substrate (1). However, it is acceptable to set the possible area (E) in the area obtained by subtracting the retaining hole area (A) from the entire area of ​​the carrier substrate (1) without setting the restricted area (D).

[0072] In addition, the work carrier (10) of Example 1 shows an example in which the area ratio of the abrasive retaining hole (3) is set to a value approximately equal to the design ratio. However, it is not necessary to set the area ratio of the abrasive retaining hole (3) to a value approximately equal to the design ratio, and it is acceptable for the difference between the area ratio of the abrasive retaining hole (3) and the design ratio to deviate from a predetermined range.

[0073] In addition, in Example 1, as shown in the flowchart illustrated in FIG. 2, an example was presented in which an abrasive supply area (C) is set (step (S5) or step (S6)), the area ratio of the abrasive supply area (C) is calculated (step (S7)), then a possible area (E) is set (step (S10) or step (S11)), and the area ratio of the possible area (E) is calculated (step (S12)). However, the design procedure for the abrasive retaining hole (3) is not limited to the procedure shown in FIG. 2. For example, after setting the entire area of ​​the carrier substrate (1), the possible area (E) is set, and the area ratio of the possible area (E) is calculated. Next, after setting the retaining hole area (A), the abrasive supply area (C) is set, and the area ratio of the abrasive supply area (C) is calculated. After that, the design ratio is calculated, and the area ratio of the abrasive retaining hole (3) is calculated, and the abrasive retaining hole (3) is designed. Furthermore, it is acceptable to subdivide elements within each step or replace processing procedures.

[0074] In the work carrier (10) of Example 1, an example is shown in which an abrasive holding hole (3) of a size capable of holding an abrasive is formed in the carrier substrate (1) as a second opening that does not hold a work. However, the second opening that does not hold a work does not necessarily have to have a size capable of holding an abrasive. For example, the second opening may be formed by a plurality of mesh-shaped holes.

[0075] Furthermore, in Example 1, by setting an abrasive supply area (C) on the inner circumference of the retaining hole area (A) that contacts the outer circumference of the workpiece, it becomes possible to intentionally cause roll-off of the workpiece. That is, the workpiece carrier (10) of Example 1 can control the machining precision of the workpiece by the carrier design (design of the workpiece carrier (10)).

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

[0077] 10: Work Carrier 1: Carrier substrate 2: Workpiece retention hole (first opening) 3: Abrasive retention hole (second opening) A: Retention hole area B: Abrasive inhibition zone C: Abrasive supply area D: Restricted area E: Possible area

Claims

Claim 1 In a work carrier having a first opening for holding a work and a second opening for holding an abrasive formed on a carrier substrate, the carrier substrate is provided with a region (A) where the first opening is formed, a region (C) inside the region (A) where the supply of an abrasive is required, and a region (E) capable of forming the second opening. At each radial position of the carrier substrate, the ratio of the area occupied by the region (C) along the periphery of the carrier substrate is calculated as the area ratio of the region (C). At each radial position of the carrier substrate, the ratio of the area occupied by the region (E) along the periphery of the carrier substrate is calculated as the area ratio of the region (E). At a radial position where 'area ratio of region (C) > area ratio of region (E)', the value of the area ratio of the region (E) is taken, and at a radial position where 'area ratio of region (C) < area ratio of region (E)', the value of the area ratio of the region (C) is taken, and 'area ratio of region (C) = (E) A work carrier characterized by the fact that, at a radial position that is the 'area ratio of the region', the value of the area ratio of region (C) or the area ratio of region (E) is taken to calculate the design ratio, and the second opening is formed in region (E) at each radial position of the carrier substrate, and the ratio of the area obtained according to the periphery direction of the carrier substrate is set based on the design ratio. Claim 2 A work carrier according to claim 1, wherein the above-mentioned (C) region becomes the region obtained by subtracting the above-mentioned (B) region from the above-mentioned (A) region when the (B) region that suppresses the supply of abrasive material is set inside the above-mentioned (A) region, and becomes the entire region of the above-mentioned (A) region when the above-mentioned (B) region is not set. Claim 3 A work carrier according to claim 1 or 2, wherein the (E) region is the region obtained by subtracting the (A) region and the (D) region from the entire carrier substrate when the (D) region is set to limit the formation of the second opening in the region obtained by subtracting the (A) region from the entire carrier substrate, and when the (D) region is not set, the (E) region is the region obtained by subtracting the (A) region from the entire carrier substrate. Claim 4 A work carrier characterized in that, in claim 1 or 2, the area ratio of the second opening is set such that the difference from the design ratio is zero (0) or the difference from the design ratio falls within a selected range. Claim 5 A work carrier characterized in that, in paragraph 3, the area ratio of the second opening is set such that the difference from the design ratio is zero (0) or the difference from the design ratio falls within a selected range.

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