Grinding media

Abstract

To provide a polishing body which can reduce disposal of abrasive grains, and can reduce time and cost required for replacement of a fixed abrasive grain grinding stone tool.SOLUTION: A polishing machine includes a surface plate 13 rotating around a shaft center O1, and a carrier 22 for holding a wafer 20 as a polished object so as to be relatively rotatable with respect to the surface plate 13. A polishing body 1 is fixed to a fixed surface 13a of the surface plate 13. The polishing body 1 has a first adhesive layer 3, a substrate 5, a second adhesive layer 7, and a fixed abrasive grain layer 9. The substrate 5 has a first surface 5a, and a second surface 5b which faces a side opposite to the first surface 5a and is separated from the first surface in a thickness direction. The fixed abrasive grain layer 9 has a polished surface 9a, and a fixed surface 9b which faces a side opposite to the polished surface 9a, and is separated from the polished surface 9a in the thickness direction. The first adhesive layer 3 is provided between the fixed surface 13a and the first surface 5a, and the second adhesive layer 7 is provided between the second surface 5b and the fixed surface 9b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an abrasive body. [Background technology]

[0002] A polishing machine is known that includes a platen and a carrier. The platen has a fixed surface extending in a direction perpendicular to its axis and is rotated about the axis. The carrier holds a flat workpiece to be polished so that it can rotate relative to the platen.

[0003] When using this polishing machine to polish wafers made of silicon carbide (SiC), gallium nitride (GaN), or the like, a polishing body is fixed to the fixed surface of a surface plate, and the wafer is held by a carrier so that it can rotate relative to the surface plate. Then, the wafer is rotated relative to the surface plate while the polishing body and the wafer are brought into contact with each other at a predetermined surface pressure in the presence of a polishing liquid.

[0004] In the lapping process for semiconductor wafers, a loose abrasive method using a polishing liquid containing abrasive particles has traditionally been used, but the waste of large amounts of expensive ceramic abrasive grains has been a problem. Meanwhile, there has been a technological shift to fixed abrasive grinding tools, and Patent Documents 1 and 2 disclose fixed abrasive grinding tools in which an abrasive body is fixed to the upper surface of a surface plate. The abrasive body in this fixed abrasive grinding tool consists of multiple segment grinding wheels attached to the upper surface of the surface plate with an adhesive. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Jikko No. 57-60929 [Patent Document 2] Patent No. 3594073 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional fixed-abrasive grinding tools described above, the numerous grinding stone segments that make up the grinding body are directly attached to the surface plate with an adhesive, so when the grinding body is replaced, the grinding body along with the expensive surface plate must be discarded. Alternatively, the grinding body along with the surface plate must be returned to the manufacturer, and the manufacturer must remove and attach the grinding stone segments, which requires a great deal of time and cost.

[0007] The present invention has been made in consideration of the above-mentioned situation, and the problem to be solved is to provide a polishing body that can reduce the waste of abrasive grains and reduce the time and cost required to replace the polishing body. [Means for solving the problem]

[0008] The polishing body of the present invention is used in a polishing machine including a platen having a fixing surface extending in a direction perpendicular to an axis and rotated about the axis, and a carrier that holds a flat plate-shaped object to be polished so that the object can rotate relatively to the platen, a polishing body fixed to the fixing surface and polishing the object to be polished under a predetermined surface pressure, a first adhesive layer, a substrate, a second adhesive layer, and a fixed abrasive layer; the substrate has a first surface and a second surface facing away from the first surface and spaced apart in a thickness direction from the first surface; the fixed abrasive layer has a polishing surface and a fixed surface facing away from the polishing surface and spaced apart from the polishing surface in a thickness direction; the first adhesive layer is provided between the fixing surface and the first surface, The second adhesive layer is provided between the second surface and the fixed surface. 、 the substrate is made of a resin having a critical surface tension of 35 dyne / cm or more; the second surface has an arithmetic mean roughness Ra of 0.1 to 1.0 μm; The second adhesive layer has a hardness of Shore D50 or more when cured. It is characterized by the following.

[0009] In the polishing body of the present invention, a fixed abrasive layer is fixed to the second surface of the substrate by a second adhesive layer. The first surface of the substrate, to which the fixed abrasive layer is fixed, is then fixed to the fixing surface of the surface plate by a first adhesive layer. That is, the polishing body of the present invention can be easily applied to a polishing machine by attaching a substrate, to which the fixed abrasive layer has been previously fixed, to the fixing surface of the surface plate. This polishing machine can reduce the amount of abrasive waste.

[0010] Furthermore, when replacing the polishing body, the substrate with the fixed abrasive layer fixed thereto can be simply removed from the fixing surface of the surface plate or attached to the fixing surface of the surface plate, which saves time and costs compared to the process of removing and attaching many segmented grindstones to the surface plate.

[0011] Therefore, the polishing body of the present invention can reduce the amount of abrasive grains that are discarded, and can also reduce the time and cost required for replacing the polishing body. [Effects of the Invention]

[0012] The polishing body of the present invention can reduce the amount of abrasive grains that are discarded, and can also reduce the time and cost required to replace the polishing body. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an enlarged portion of the polishing body of Example 1. [Figure 2] FIG. 2 is a plan view of the polishing body of Example 1. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an enlarged portion of a tip constituting the fixed abrasive layer of the polishing body of Example 1. FIG. [Figure 4] FIG. 4 is a perspective view of a platen to which the polishing body of Example 1 is fixed. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an enlarged portion of the polishing body of Example 1 fixed to a platen. [Figure 6] FIG. 6 is a schematic cross-sectional view of a wafer polishing machine. DETAILED DESCRIPTION OF THE INVENTION

[0014] The polishing body of the present invention is used in a polishing machine equipped with a platen and a carrier. The platen has a fixing surface extending in a direction perpendicular to its axis and is rotated about its axis. The carrier holds a flat workpiece to be polished so that it can rotate relative to the platen.

[0015] The workpiece to be polished by the polishing body of the present invention can be a semiconductor wafer. In particular, a polishing machine to which this polishing body is attached can be suitably used in a lapping process to roughly process the semiconductor wafer or to subsequently finish it. The lapping process can be either a single-sided lapping process in which only one side of the semiconductor wafer as the workpiece is lapped, or a double-sided lapping process in which both sides of the semiconductor wafer are simultaneously lapped by a pair of polishing bodies.

[0016] This polishing body has a first adhesive layer, a substrate, a second adhesive layer, and a fixed abrasive layer, which are laminated in this order.

[0017] The substrate has a first surface and a second surface facing away from the first surface and spaced apart in the thickness direction from the first surface. A first adhesive layer is provided between the fixing surface of the surface plate and the first surface of the substrate, and the fixing surface of the surface plate and the first surface of the substrate are bonded together by the first adhesive layer.

[0018] The substrate can be made of metal or the like, but is preferably made of a flexible resin. A flexible substrate can contribute to reducing micro-scratches on the polished surface. Furthermore, a resin substrate can contribute to reducing the weight of the polishing body.

[0019] The resin used for the substrate preferably has a critical surface tension of 35 dyne / cm or more. This improves the wettability between the substrate and the adhesive of the second adhesive layer. As a result, the fixed abrasive layer is prevented from peeling off from the substrate during polishing, thereby minimizing damage to the polished surface. Specific examples of resins with a critical surface tension of 35 dyne / cm or more include polyethylene terephthalate, nylon, polyvinylidene chloride, polyvinyl chloride, and polyvinyl alcohol.

[0020] The second surface of the substrate is preferably roughened. If the second surface is appropriately roughened, the contact area between the second surface and the second adhesive layer increases, and an anchor effect at the contact interface is also expected, which can increase the adhesive strength of the second adhesive layer to the second surface. As a result, the bondability of the fixed abrasive layer to the substrate can be improved.

[0021] The degree of roughening of the second surface is preferably such that the surface roughness Ra (arithmetic mean roughness) value of the second surface is 0.1 to 1.0 μm. If the Ra value is less than 0.1 μm, the effect of roughening the second surface is likely to be insufficient. On the other hand, if the Ra value exceeds 1.0 μm, there is a risk of adversely affecting the processing accuracy of the surface to be polished.

[0022] The thickness of the substrate is not particularly limited, but is preferably about 1 to 10 mm. If the substrate is too thick, the flexibility may decrease, and if the substrate is too thin, the handleability of the polishing body of the present invention may decrease.

[0023] The shape of the substrate can be made to correspond to the shape of the fixing surface of the platen to which the polishing body of the present invention is attached.

[0024] The fixed abrasive layer has a polishing surface and a fixed surface facing away from the polishing surface and spaced apart in the thickness direction from the polishing surface. A second adhesive layer is provided between the second surface of the substrate and the fixed surface of the fixed abrasive layer, and the second surface of the substrate and the fixed surface of the fixed abrasive layer are bonded together by the second adhesive layer.

[0025] The fixed abrasive layer may have a bond layer and numerous abrasive grains held by the bond layer, which makes it easy to adjust the surface density and size of the abrasive grains on the polishing surface.

[0026] The bond layer may be made of metal, resin, or ceramic, but is preferably made of ceramic such as glass. For example, a dense vitreous bond layer may be made of a powder or paste of a glass binder containing frit such as borosilicate glass, which is then formed into chips, sheets, or the like, melted, and solidified. When a vitreous bond layer is used, its composition is not particularly limited, and it may be made of vitreous materials such as borosilicate glass, crystallized glass, or quartz glass.

[0027] As the abrasive grains, diamond, CBN, silicon carbide, boron carbide, alumina, ceria, silica, zirconia, silicon nitride, mullite, yttria-stabilized zirconia, etc. can be used, but among these, it is preferable to include at least one of diamond, CBN, silicon carbide, boron carbide, alumina, ceria, and silica.

[0028] The fixed abrasive layer can be composed of multiple chips spaced apart on the second surface of the substrate. In this case, a second adhesive layer can be provided between the second surface and each chip. If the fixed abrasive layer is composed of multiple chips held on a substrate, the multiple chips can be attached to or removed from the surface plate by adhering or removing the substrate from the fixed surface of the surface plate, facilitating the attachment and detachment of the fixed abrasive layer to or from the surface plate. Furthermore, the spaces between each chip can serve as passages for the polishing liquid.

[0029] When the fixed abrasive layer is composed of a plurality of chips, the shape, size, thickness and number of the chips are not particularly limited and can be set appropriately according to the requirements of the polishing body.

[0030] The type of adhesive used in the first adhesive layer and the second adhesive layer is not particularly limited, and can be appropriately selected from thermoplastic resin-based, thermosetting resin-based, and elastomer-based adhesives.

[0031] The adhesive for the first adhesive layer for adhering the substrate to the fixing surface of the surface plate is preferably an acrylic or silicone adhesive that has high shear strength and peel strength.

[0032] It is preferable that a release paper is provided on the surface of the first adhesive layer that is bonded to the fixing surface. This release paper prevents deterioration of the first adhesive layer when attached to the first adhesive layer, and enables the first adhesive layer to adhere to the fixing surface by peeling it off from the first adhesive layer. It is preferable to use a double-sided tape with release paper as the first adhesive layer that has release paper provided on the surface that is bonded to the fixing surface.

[0033] The adhesive for the second adhesive layer for bonding the fixed abrasive layer to the substrate is preferably an epoxy adhesive with high shear strength.

[0034] From the viewpoint of improving the processing accuracy of the polished surface, the adhesive used in the second adhesive layer preferably has a hardness of Shore D50 or more, and more preferably Shore D70 or more, when hardened.

[0035] The preferred combination of materials for the components constituting the polishing body of the present invention is an acrylic or silicone-based first adhesive layer, a polyethylene terephthalate substrate, an epoxy-based second adhesive layer, and a fixed abrasive layer having countless abrasive grains and a dense glass-containing bond layer that bonds the abrasive grains. This combination prevents the fixed abrasive layer from peeling off from the substrate during polishing, improves the polishing accuracy of the surface to be polished, and makes it easy to attach and detach the polishing body to and from the platen.

[0036] In the polishing body of the present invention, the fixed abrasive layer is fixed to the substrate, which reduces the amount of abrasive waste.Furthermore, by simply attaching and detaching the substrate to which the fixed abrasive layer is fixed to the surface plate, the time and cost required for replacing the polishing body can be reduced.

[0037] Example 1 Hereinafter, Examples 1 to 3 embodying the present invention will be described. 3. Reference examples 1~4 Examples 1 to 3 are described below, and comparative examples are also described. 3. Reference examples 1~4 In the examples and comparative examples, Table 1 shows the types of adhesives used in the first adhesive layer and the second adhesive layer, and the types of resins used in the substrate.

[0038] [Table 1]

[0039] Example 1 1, the polishing body 1 of Example 1 has a first adhesive layer 3, a substrate 5, a second adhesive layer 7, a fixed abrasive layer 9, and a release paper 11. The release paper 11 is peeled off from the polishing body 1, and the polishing body 1 is attached to a fixing surface 13a of a platen 13, as shown in FIG.

[0040] The substrate 5 has a first surface 5a and a second surface 5b facing away from the first surface 5a and spaced apart in the thickness direction from the first surface 5a. The substrate 5 is adhered to the base 13 by a first adhesive layer 3 provided between the first surface 5a and the fixing surface 13a.

[0041] The substrate 5 is made of polyethylene terephthalate (PET) with a critical surface tension of 43 dyne / cm. The substrate 5 has a shape corresponding to the fixing surface 13a of the surface plate 13 to which the polishing body 1 is attached. As shown in FIG. 4, the surface plate 13 is a circular plate having a diameter of 300 mm and a central hole 13b formed therethrough. The substrate 5 is also a circular plate having a diameter of 300 mm and a central hole 5c formed therethrough. The substrate 5 is made by cutting a commercially available PET plate into a predetermined shape.

[0042] The thickness of the substrate 5 was 1 mm. The second surface 5b of the substrate 5 was buffed to have a surface roughness Ra value of 0.15 μm. The surface roughness was measured using a surface roughness measuring device (Mitsutoyo's "SURFTEST SJ-210").

[0043] The fixed abrasive layer 9 has a polishing surface 9a and a fixed surface 9b facing away from the polishing surface 9a and spaced apart in the thickness direction from the polishing surface 9a. The fixed abrasive layer 9 is bonded to the substrate 5 by a second adhesive layer 7 provided between the second surface 5b and the fixed surface 9b.

[0044] 1 and 2, the fixed abrasive layer 9 is composed of a plurality of chips 90 each having a disk-like segmented grindstone shape with a diameter of 30 mm and a thickness of 2 mm. The plurality of chips 90 are arranged uniformly over the entire surface of the second surface 5b of the substrate 5 with intervals therebetween. In this embodiment, 54 chips 90 are arranged with intervals between each other.

[0045] 3, each tip 90 has a glassy bond layer 91 and numerous diamond abrasive grains 92 held in the bond layer 91. The bond layer 91 includes pores 93 and has multiple layers of abrasive grains 92.

[0046] A commercially available double-sided tape having a release paper 11 is attached to the first surface 5a of the substrate 5. The first adhesive layer 3 is made of an acrylic adhesive of this double-sided tape. The release paper 11 is provided on the surface of the first adhesive layer 3 that is to be bonded to the fixing surface 13a.

[0047] The adhesive constituting the second adhesive layer 7 is made of a commercially available epoxy adhesive, which has a Shore hardness of D75 when cured.

[0048] The abrasive body 1 was produced as follows.

[0049] First, a known glass binder containing frit such as borosilicate glass and abrasive grains 92 made of diamond (average grain size 15 μm) were prepared.

[0050] A dispersant, vehicle, and pore-forming agent were added to the glass binder and diamond abrasive grains 92 and stirred. The stirred paste was dried at 80°C for 12 hours, and the dried powder was mixed in a mortar. The powder was then press-molded into numerous chip-shaped bodies. These bodies were fired at a predetermined temperature to evaporate the pore-forming agent and melt the glass binder. After a certain period of time, the bodies were slowly cooled to room temperature, solidifying the glass binder and forming a bond layer 91. In this way, a chip 90 was manufactured, which had a dense glass bond layer 91, diamond abrasive grains 92 held in this bond layer 91, and pores 93 formed in the bond layer.

[0051] The obtained chip 90 was attached uniformly to the entire second surface 5b of the substrate 5 using the epoxy adhesive. Finally, the double-sided tape was attached to the first surface 5a of the substrate 5, and the polishing body 1 was completed.

[0052] The polishing body 1 thus obtained is attached to the fixing surface 13a of the surface plate 13 by the first adhesive layer 3 from which the release paper 11 has been peeled off, and is used as a fixed abrasive grindstone tool.

[0053] Example 2 Polyvinyl chloride (PVC) having a critical surface tension of 39 dyne / cm was used as the resin forming the substrate 5. The Ra value of the second surface 5b of this substrate 5 was set to 0.15 μm.

[0054] As the adhesive constituting the first adhesive layer 3, a silicone adhesive from a commercially available double-sided tape was used.

[0055] The other configurations are the same as those in the first embodiment.

[0056] Example 3 The Ra value of the second surface 5b of the substrate 5 was set to 0.80 μm.

[0057] The other configurations are the same as those in the first embodiment.

[0058] ( Reference example 1 ) Polyethylene (PE) having a critical surface tension of 31 dyne / cm was used as the resin forming the substrate 5. The Ra value of the second surface 5b of this substrate 5 was set to 0.15 μm.

[0059] As in Example 2, the adhesive constituting the first adhesive layer 3 was a silicone adhesive.

[0060] The other configurations are the same as those in the first embodiment.

[0061] ( Reference example 2 ) The Ra value of the second surface 5b of the substrate 5 was set to 0.01 μm.

[0062] As in Example 2, the adhesive constituting the first adhesive layer 3 was a silicone adhesive.

[0063] The other configurations are the same as those in the first embodiment.

[0064] ( Reference example 3 ) The Ra value of the second surface 5b of the substrate 5 was set to 1.20 μm.

[0065] As in Example 2, the adhesive constituting the first adhesive layer 3 was a silicone adhesive.

[0066] The other configurations are the same as those in the first embodiment.

[0067] ( Reference example 4 ) The Ra value of the second surface 5b of the substrate 5 was set to 0.15 μm.

[0068] As in Example 2, the adhesive constituting the first adhesive layer 3 was a silicone adhesive.

[0069] Furthermore, as the adhesive constituting the second adhesive layer 7, a commercially available epoxy adhesive having a hardness of Shore D40 when cured was used.

[0070] The other configurations are the same as those in the first embodiment.

[0071] (Comparative Example) A plurality of chips 90 were manufactured in the same manner as in Example 1.

[0072] The obtained chips 90 were directly attached to the entire fixed surface 13a of the surface plate 13 using the same epoxy adhesive (hardness when hardened: Shore D75) as in Example 1 to form a fixed grindstone abrasive tool for the comparative example.

[0073] (Processing test) A wafer polishing machine (Engis EJW-380) shown in FIG. 6 was prepared, and the wafers in Examples 1 to 6 were polished. 3. Reference examples 1~4 A lapping test was carried out to polish a wafer 20 using a fixed abrasive tool in which the polishing body 1 was attached to a surface plate 13 and a comparative fixed abrasive tool.

[0074] This wafer polishing machine is equipped with multiple carriers 22, a surface plate 13, a drive unit 24, and a polishing liquid supply unit 26. Although only a single carrier 22 is shown in FIG. 6, the wafer polishing machine actually has multiple carriers 22. Each carrier 22 is shaped like a horizontal disk. A wafer fixing surface 22a is recessed in the underside of each carrier 22, and a wafer 20 is fixed to the wafer fixing surface 22a. A carrier rotation shaft 28 protrudes vertically from the upper surface of each carrier 22. The polished surface 20a, which is the Si surface of each wafer 20, faces downward.

[0075] The surface plate 13 has a central hole 13b and is a horizontal disk shape that contains all the carriers 22. A surface plate rotation shaft 30 is inserted into and fixed to the central hole 13b of the surface plate 13. The upper surface of the surface plate 13 is a fixing surface 13a. The fixing surface 13a is provided with the wafers 20 facing each other. 3. Reference examples 1~4 The polishing body 1 and the plurality of chips 90 of the comparative example are fixed by adhesive.

[0076] The drive device 24 has a main drive device 24a, an auxiliary drive device 24b, and a pressure device 24c. The main drive device 24a drives the surface plate rotation shaft 30 to rotate at a predetermined speed around the first axis O1. The auxiliary drive device 24b drives each carrier rotation shaft 28 to rotate at a predetermined speed around the second axis O2. The pressure device 24c applies pressure to each carrier rotation shaft 28 and the auxiliary drive device 24b toward the surface plate 13 with a predetermined load.

[0077] The polishing liquid supply device 26 is provided above the surface plate 13. The polishing liquid supply device 26 provides a polishing liquid 26a between each wafer 20 and the polishing body 1. The polishing liquid 26a is made of water and does not contain abrasive particles.

[0078] Using this wafer polishing machine, a processing test was carried out to polish the wafer 20 under the following conditions. Wafer 20 as the workpiece: 4-inch diameter 4H-SiC single crystal Flow rate of polishing liquid 26a: 10 mL / min Load: 30kPa Rotation speed of surface plate 13: 60 rpm Carrier 22 rotation speed: 60 rpm Processing time: 10 minutes

[0079] (Evaluation of adhesive strength) After the above processing test, the adhesive strength of the chips 90 was evaluated on the fixed abrasive layer 9. The adhesive strength was evaluated as ◯ if no chips 90 peeled off at all, and △ if five or fewer chips 90 peeled off. The results are shown in Table 2.

[0080] Examples 1 to 3 in which the resin constituting the substrate 5 is polyethylene terephthalate or polyvinyl chloride having a critical surface tension of 35 dyne / cm or more, and the Ra value of the second surface 5b of the substrate 5 is 0.1 μm or more; Reference examples 3 and 4 In all the abrasive bodies 1, no chips 90 peeled off.

[0081] The resin constituting the substrate 5 is polyethylene with a critical surface tension of less than 35 dyne / cm. Reference example 1In the case of the second adhesive layer 7, the bonding strength of the chip 90 was slightly reduced. This is thought to be because the wettability at the interface between the second surface 5b of the substrate 5 and the second adhesive layer 7 was reduced.

[0082] The Ra value of the second surface 5b of the substrate 5 is less than 0.1 μm. Reference example 2 In the case of the second adhesive layer 7, the bonding strength of the chip 90 was slightly reduced. This is thought to be because the contact area and anchor effect at the interface between the second surface 5b of the substrate 5 and the second adhesive layer 7 were reduced.

[0083] (Evaluation of the flatness of the polished surface) After the above processing test, the processed flatness was evaluated for the polished surface 20a of the wafer 20. That is, for the polished surface 20a after the processing test, a five-point measurement was performed on the wafer surface, measuring the wafer thickness at the center point within the wafer surface and four points on the wafer periphery, and the difference between the maximum and minimum values ​​of the measured thickness was taken as the measured value of TV5.

[0084] The evaluation of the processing flatness was as follows: if the TV5 value was 2.0 μm or less, ⊚; if the TV5 value was more than 2.0 μm and 4 μm or less, ○; if the TV5 value was more than 4 μm, △. The results are shown in Table 2.

[0085] In Examples 1 to 5, the Ra value of the second surface 5b of the substrate 5 is set to 1.0 μm or less and the hardness of the second adhesive layer 7 is set to Shore D50 or more. 3, Reference examples 1 and 2 In all cases, the TV5 value was 2.0 μm or less, and the processing flatness was extremely good.

[0086] The Ra value of the second surface 5b of the substrate 5 was set to 1.20 μm. Reference example 3 In the case of the second surface 5b of the substrate 5, the processing flatness of the surface 20a to be polished was slightly reduced. This is thought to be due to the influence of the high surface roughness of the second surface 5b of the substrate 5.

[0087] The hardness of the second adhesive layer 7 is Shore D40. Reference example 4 In the case of the polished surface 20a, the processed flatness of the polished surface 20a was slightly reduced. This is thought to be due to the softness of the second adhesive layer 7.

[0088] (Tool change time evaluation) Example 1 3. Reference examples 1~4 The tool replacement time was evaluated for a fixed abrasive grinding tool in which the polishing body 1 was attached to the surface plate 13, and a comparative fixed abrasive grinding tool in which a plurality of chips 90 were directly attached to the surface plate 13. The results are shown in Table 2.

[0089] Example 1 3. Reference examples 1~4 The replacement time for the polishing body 1 was 10 minutes, which was significantly shorter than the 300 minutes required for the comparative example.

[0090] [Table 2]

[0091] As described above, the present invention is described in Examples 1 to 3 However, the present invention has been described in accordance with the above-mentioned Examples 1 to 3 It goes without saying that the present invention is not limited to the above and can be appropriately modified and applied within the scope of the present invention. [Industrial Applicability]

[0092] The present invention can be used, for example, in lapping semiconductor wafers. [Explanation of symbols]

[0093] 1...Abrasive body 3...First adhesive layer 5...Substrate 5a...Side 1 5b…Second side 7…Second adhesive layer 9...Fixed abrasive layer 9a…Polished surface 9b…Fixed surface 11...Release paper 13...Surface plate 13a…Fixed surface 90…chip 91...Bond layer 92...Abrasive grain

Claims

1. The present invention is used in a polishing machine including a surface plate having a fixing surface extending in a direction perpendicular to an axis and rotated around the axis, and a carrier that holds a flat workpiece to be polished so that the workpiece can rotate relatively to the surface plate, a polishing body fixed to the fixing surface and polishing the object to be polished under a predetermined surface pressure, a first adhesive layer, a substrate, a second adhesive layer, and a fixed abrasive layer; the substrate has a first surface and a second surface facing away from the first surface and spaced apart in a thickness direction from the first surface; the fixed abrasive layer has a polishing surface and a fixed surface facing away from the polishing surface and spaced apart from the polishing surface in a thickness direction; the first adhesive layer is provided between the fixing surface and the first surface, the second adhesive layer is provided between the second surface and the fixed surface, the substrate is made of a resin having a critical surface tension of 35 dyne / cm or more; the second surface has an arithmetic mean roughness Ra of 0.1 to 1.0 μm; The polishing body is characterized in that the second adhesive layer has a hardness of Shore D50 or more when hardened.

2. The critical surface tension is 39 dyne / cm or more, the second surface has an arithmetic mean roughness Ra of 0.15 to 0.8 μm; 2. The abrasive body according to claim 1, wherein the second adhesive layer has a hardness of Shore D75 or more when cured.

3. 3. The polishing body according to claim 1, wherein the substrate is flexible.

4. An abrasive body as described in any one of claims 1 to 3, wherein the surface of the first adhesive layer that is adhered to the fixing surface is provided with a release paper that suppresses deterioration of the first adhesive layer when attached and enables adhesion to the fixing surface by peeling it off.

5. the first adhesive layer is acrylic or silicone-based; the substrate is polyethylene terephthalate; 5. The polishing body according to claim 1, wherein the fixed abrasive layer comprises a number of abrasive grains and a bond layer containing a dense glassy substance that bonds the abrasive grains together.

6. the fixed abrasive layer is made of a plurality of chips arranged at intervals on the second surface, 6. The polishing body according to claim 1, wherein the second adhesive layer is provided between the second surface and each of the chips.

7. the object to be polished is a semiconductor wafer, 7. The polishing body according to claim 1, which is used for lapping the object to be polished.

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