Abrasive roll

Abstract

The present invention provides a polishing pad that, even when polishing a workpiece with a circuit formed on it, such as a printed circuit board, prevents the generated waste from getting stuck in the irregularities between the wiring, thereby improving the yield in the polishing process of the workpiece with the wiring formed on it. [Solution] The polishing roll according to the present invention is a polishing roll using a nonwoven abrasive material which is fixed to a nonwoven fabric base material that is made by three-dimensionally intertwining synthetic fibers and bonding the intertwining points between the synthetic fibers with a binder resin, using a synthetic resin adhesive in which abrasive particles are dispersed and mixed, and the fiber diameter of the synthetic fibers is 50 μm to 88 μm.

Description

Technical Field

[0001] The present invention relates to a polishing roll using a non-woven abrasive material, which is optimal for polishing an object to be polished having a circuit formed thereon, such as a printed wiring board, and having unevenness between wirings.

Background Art

[0002] Conventionally, for polishing printed wiring boards and plate-like metal materials such as copper and aluminum, polishing rolls as disclosed in Patent Document 1 are used. These polishing rolls are made by arranging a large number of rectangular non-woven abrasive materials in which abrasive grains are fixed to a nylon non-woven fabric radially on the outer peripheral surface of a cylindrical core material and integrating them using an adhesive, or cutting the non-woven abrasive material into a donut shape and piercing a plurality of them through a cylindrical core material and integrating them in a state compressed in the axial direction of the core material, or winding a long non-woven abrasive material around the outer peripheral surface of the core material and integrating them using a binder resin. These polishing rolls are characterized in that as the non-woven abrasive material is consumed, new polishing layers continuously appear and the polishing performance is maintained, and due to the flexibility of the open three-dimensional structure, they have good conformity to the surface of the object to be polished and can obtain a uniform and constant roughness processing surface with few scratches. Also, due to their open three-dimensional structure, they are widely used because they are less clogged with chips from the object to be polished and can release the generated polishing heat.

[0003] However, with these conventional polishing rolls, when polishing an object to be polished having wirings formed thereon, such as a printed wiring board, the chips generated from the polishing roll clog between the wirings, which causes poor solder resist adhesion and poor appearance in subsequent processes and reduces the yield.

[0004] Japanese Patent Application Laid-Open No. 2007-313621 describes clogging of chips generated by polishing into through holes on a printed board. However, with a polishing roll having the same configuration, clogging between wirings has not been reduced.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2003-175471 [Patent Document 2] Japanese Patent Publication No. 2007-313621 [Overview of the project] [Problems that the invention aims to solve]

[0006] This invention was made in view of the above problems, and aims to reduce clogging between wiring caused by consumable debris generated from the polishing roll when polishing an object to be polished that has fine irregularities, such as a printed circuit board on which a circuit is formed. [Means for solving the problem]

[0007] The invention described in claim 1 is a polishing roll using a nonwoven abrasive material, which is formed by three-dimensionally intertwining synthetic fibers and bonding the intertwining points between the synthetic fibers with a binder resin, and then fixing the nonwoven abrasive material to the nonwoven base material using a synthetic resin adhesive in which abrasive particles are dispersed and mixed, characterized in that the fiber diameter of the synthetic fibers is 50 μm to 88 μm, and is a polishing roll for preventing clogging between wiring. [Effects of the Invention]

[0008] In the polishing roll according to the present invention, even when polishing a workpiece on which a circuit has been formed, such as a printed circuit board, the generated waste material is less likely to get stuck in the irregularities between the wiring, and as a result, the yield in the polishing process of the workpiece on which the wiring has been formed is improved. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view illustrating one embodiment of the nonwoven abrasive material used in the present invention. [Figure 2] Figure 1 is an enlarged diagram illustrating a portion of the nonwoven abrasive material shown. [Figure 3]This is a partially enlarged perspective view illustrating one embodiment of the polishing roll according to the present invention. [Figure 4] This diagram illustrates the manufacturing procedure for a polishing roll for removing hole-filling ink according to the present invention, wherein (a) shows a state in which rectangular nonwoven abrasive materials are placed side by side, (b) shows a state in which the side by side nonwoven abrasive materials are compressed in the direction of side by side, and (c) shows a state in which the compressed and fixed nonwoven abrasive materials are wound around a core material. [Figure 5] This is a schematic diagram showing another embodiment of the manufacturing method of the polishing roll according to the present invention (a method of compressing and fixing a donut-shaped nonwoven fabric). [Figure 6] This is a schematic diagram showing yet another embodiment of the manufacturing method of the polishing roll according to the present invention (a method of winding a long nonwoven abrasive material). [Modes for carrying out the invention]

[0010] Figure 1 is a perspective view illustrating one embodiment of the nonwoven abrasive material used in the present invention, and Figure 2 is an enlarged view illustrating a part of the nonwoven abrasive material shown in Figure 1. The nonwoven abrasive material 10 includes a nonwoven base material 12. The nonwoven base material 12 is a nonwoven fabric in which synthetic fibers 14 are three-dimensionally intertwined and the intertwined points of the synthetic fibers 14 are bonded together with a binder resin 16. As the synthetic fibers 14 constituting the nonwoven base material 12, vinylon fibers are preferably used to improve the ability to remove hole-filling ink. Synthetic fibers 14 with a fiber diameter in the range of 10 μm to 100 μm can be used. The synthetic fibers 14 only need to have a fiber diameter within this range, and may be used with a single fiber diameter or a combination of multiple fibers with different fiber diameters.

[0011] The nonwoven fabric base material 12 is manufactured using cross-web, random-web, spunbond, or papermaking methods. Among these, it is preferable to manufacture it using cross-web or random-web methods, as these methods allow for greater web thickness, resulting in less clogging from polishing debris, high heat dissipation, and easy density control during the creation of polishing rolls. Furthermore, it is preferable to apply needle punching to the webs manufactured using these methods in order to control the density of the web.

[0012] As the binder resin 16, SBR resin, NBR resin, acrylic acid ester, melamine resin, phenolic resin, etc., can be used individually or in combination. Furthermore, among these, SBR resin and acrylic acid ester are preferred because they can produce a highly flexible nonwoven fabric base material 12. As for the application method of the binder resin 16, known methods such as spraying and dipping can be used individually or in combination.

[0013] The nonwoven fabric substrate 12 is fixed to the nonwoven fabric substrate 12 by a synthetic resin adhesive 20, with abrasive grains 18 dispersed and mixed inside. The abrasive grains 18 can be any material commonly used as abrasive grains, such as silicon carbide, aluminum oxide, silica, chromium oxide, cerium oxide, synthetic diamond, CBN (cubic boron nitride), or garnet. The particle size of the abrasive grains 18 can be within the range that can be coated onto the nonwoven fabric substrate 12, and abrasive grains of an appropriate particle size can be selected depending on the polishing application.

[0014] As the synthetic resin adhesive 20, synthetic resin adhesives such as phenolic resin, epoxy resin, and urethane resin can be used, but it is preferable to use phenolic resin alone, epoxy resin alone, or a mixture of phenolic resin and epoxy resin so that the abrasive grains 18 can fully exhibit their polishing performance. The synthetic resin adhesive 20 is applied to the nonwoven fabric substrate 12 in a state in which the abrasive grains 18 are dispersed and mixed, and the application is carried out by immersion method, or by a combination of immersion method and spray method.

[0015] The non-woven abrasive material 10 according to the present invention, due to the above-described configuration, even when polishing an object to be polished having unevenness due to wiring, such as a printed wiring board, etc., the waste chips generated from the non-woven abrasive material become large, so it is difficult for the waste chips to clog in the unevenness between the wirings of the object to be polished, and it is less likely to cause clogging of waste chips between the wirings.

[0016] FIG. 3 is a partially enlarged perspective explanatory view showing an embodiment of the polishing roll according to the present invention. The polishing roll 50 is formed by juxtaposing a plurality of rectangular non-woven abrasive materials 10, compressing and fixing them in the juxtaposed direction, winding the compressed and fixed non-woven abrasive material 10a around a cylindrical core material 52, impregnating the non-woven abrasive material 10a compressed and fixed during winding with a synthetic resin, and further fixing and integrating the non-woven abrasive material 10. The non-woven abrasive material 10 is used with an appropriate number of sheets changed according to the intended use.

[0017] For the core material 52, a cylindrical one formed using a hard resin such as a phenolic resin is used.

[0018] As the synthetic resin for adhering the non-woven abrasive materials 10 to each other, a phenolic resin, an epoxy resin, a urethane resin, a foamed urethane resin, etc. can be used. However, since the urethane resin is more elastic than the phenolic resin and the epoxy resin and has good followability to the object to be polished of the polishing roll 50, it is preferable to use the urethane resin, and more preferably the foamed urethane resin. In addition, resins other than the foamed urethane resin that exhibit the same characteristics as the foamed urethane resin described above can also be used in the same manner.

[0019] In the polishing roll 50 according to the present invention, in addition to the effect exhibited by the non-woven abrasive material 10, a new polishing layer appears during polishing and the polishing performance is maintained, and it is possible to polish with few scratches, uniformly and with a certain roughness. Furthermore, since there is little clogging due to the chips shaved from the object to be polished and it has the effect of releasing the generated polishing heat, it is possible to efficiently polish an object to be polished such as a printed wiring board.

[0020] The manufacturing method of the polishing roll according to the present invention is to cut the non-woven abrasive 10 described in paragraphs 0010 to 0015 into a rectangular shape as shown in Fig. 4(a), juxtapose a plurality of sheets, and compress and fix them in the juxtaposed direction by 95 to 20% (assuming the dimension before compression is 100%) as shown in Fig. 4(b). Then, as shown in Fig. 4(c), the compression-fixed non-woven abrasive 10a is wound around a cylindrical core material 52, and at that time, it is impregnated with a synthetic resin. Specifically, it is impregnated until the synthetic resin such as the urethane resin used in the above-described embodiment uniformly penetrates. The impregnation operation may be performed either after the non-woven abrasive 10 cut into a rectangular shape is compression-fixed or after the compression-fixed non-woven abrasive 10 is wound around the core material 52. Examples of the impregnation method include immersing the non-woven abrasive 10 in a resin solution in a state where it is compression-fixed or dropping the resin solution from above the impregnated object in a state where the non-woven abrasive 10 is wound around the core material 52. This operation only needs to uniformly impregnate the compression-fixed non-woven abrasive with the resin. Even if it is other than the above-described operation procedure or method, as long as the impregnated object is uniformly impregnated with the resin for the purpose of this operation, other operation procedures or methods can be applied. Furthermore, the non-woven abrasive 10 impregnated with the synthetic resin is formed by leaving it at room temperature to 60°C for 3 to 24 hours for fixation and integration. By manufacturing in such a procedure, it is possible to fix and integrate the non-woven abrasive 10 on the outer periphery of the core material 52 with less density unevenness, eliminate the polishing unevenness of the polished object, and furthermore, the synthetic resin penetrated into the non-woven abrasive 10 described above (specifically, the foamed urethane resin used in the above-described embodiment, etc.) uniformly penetrates into the non-woven abrasive, improving the followability of the polished object and making it possible to further bring out the effect of the polishing roll using the non-woven abrasive 10 of the present invention.

[0021] The polishing roll according to the present invention is not limited to the manufacturing method described above, but may be manufactured by other methods. For example, as shown in Figure 5, multiple pieces of nonwoven abrasive material 10 cut into a donut shape are inserted into a core material 52, and compressed and fixed by 95-20% in the axial direction of the core material 52 (with the dimensions before compression being 100%) to form a roll. At that time, a synthetic resin is impregnated. Specifically, the synthetic resin, such as the urethane resin used in the above embodiment, is impregnated until it penetrates uniformly. The impregnation work may be performed either after inserting the multiple pieces of nonwoven abrasive material 10 cut into a donut shape into the core material 52, or after compressing and fixing by 95-20% in the axial direction (with the dimensions before compression being 100%) to form a roll. The impregnation method involves inserting multiple pieces of nonwoven abrasive material 10, cut into a donut shape, through the core material 52, or immersing them in a resin solution while they are compressed and fixed to 95-20% in the axial direction of the core material 52, or dripping the resin solution from the top of the object to be impregnated. This process is sufficient if the resin is uniformly impregnated into the compressed and fixed nonwoven abrasive material. Any other work procedure or method can be applied as long as the resin is uniformly impregnated into the object to be impregnated, which is the purpose of the process. Furthermore, the nonwoven abrasive material is formed by leaving it at room temperature to 60°C for 3 to 24 hours to fix and integrate it. Another specific example is to wrap a long piece of nonwoven abrasive material around the outer surface of the core material 52, compress and fix it to 95-20% (with the dimensions before compression as 100%), and form it into a roll shape. At that time, it is impregnated with a synthetic resin, specifically urethane resin in one specific embodiment, until the resin penetrates uniformly. The impregnation process may be performed either after the long nonwoven abrasive material has been wrapped around the outer surface of the core material 52, or after it has been compressed and fixed by 95-20% (with the dimensions before compression being 100%) to form a roll. The impregnation method may involve immersing the long nonwoven abrasive material in a resin solution while it is wrapped around the outer surface of the core material 52, or while it has been compressed and fixed by 95-20% (with the dimensions before compression being 100%) to form a roll, or by dripping the resin solution from the top of the object to be impregnated.This process only requires uniform impregnation of the compressed and fixed nonwoven abrasive material with resin. Any work procedure or method other than those mentioned above can be applied as long as the resin is uniformly impregnated into the object to be impregnated, which is the purpose of this process.

[0022] Furthermore, the nonwoven abrasive material is fixed and integrated by leaving it at room temperature to 60°C for 3 to 24 hours (see Figure 6). [Examples]

[0023] A cross web was prepared using nylon 66 fibers with a single filament fineness of 44 dtex (thickness of 70 μm) and a fiber basis weight of 136 g / m2. SBR resin was sprayed onto this cross web from both sides using a spray method as a binder resin. At this time, the SBR resin was sprayed so that the dry solid content was 40 g / m2. After that, the cross web was dried to prepare a nonwoven fabric base material 12. Next, the nonwoven fabric base material 12 was immersed in a slurry prepared by adjusting the solid ratio of phenol resin (a synthetic resin adhesive 20) and #1000 silicon carbide (abrasive grains 18) to 100 / 300 so that the dry solid content was 324 g / m2, thereby obtaining a nonwoven abrasive material 10. Next, 150 pieces of the nonwoven abrasive material 10, cut into 40 x 640 mm rectangular shapes, were compressed by 24% and fixed. The compressed and fixed nonwoven abrasive material 10a was then impregnated with foamed urethane resin, a synthetic resin, and wrapped around the outer surface of the core material 52. By leaving it at room temperature for 12 hours, the nonwoven abrasive materials 10 were fixed and integrated together to produce a polishing roll 50 measuring 150 x 610 x 76.2 mm.

[0024] (Comparative Example 1) A cross web with a fiber basis weight of 136 g / m2 was prepared by blending 50% by weight of nylon 6 fibers with a single filament fineness of 16 dtex (thickness of 42 μm) and 50% by weight of nylon 6 fibers with a single filament fineness of 11 dtex (thickness of 35 μm). SBR resin was sprayed onto this cross web as a binder resin from both sides by a spray method. At this time, the SBR resin was sprayed so that the dry solids content was 40 g / m2. After that, the cross web was dried to prepare a nonwoven fabric base material 12. Next, the nonwoven fabric base material 12 was immersed in a slurry of phenolic resin, which is a synthetic resin adhesive 20, and silicon carbide, which is an abrasive grain 18, adjusted to a solid ratio of 100 / 130, so that the dry solids content was 248 g / m2, to obtain a nonwoven abrasive material 10. Next, 130 pieces of the nonwoven abrasive material 10, cut into 40 x 640 mm rectangular shapes, were compressed by 24% and fixed. The compressed and fixed nonwoven abrasive material 10a was then impregnated with foamed urethane resin, a synthetic resin, and wrapped around the outer surface of the core material 52. By leaving it at room temperature for 12 hours, the nonwoven abrasive materials 10 were fixed and integrated together to produce a polishing roll 50 measuring 150 x 610 x 76.2 mm.

[0025] (Comparative Example 2) A cross web with a fiber basis weight of 100 g / m2 was prepared by blending 80% by weight of nylon 6 fibers with a single filament fineness of 6.6 dtex (thickness of 27 μm) and 20% by weight of nylon 6 fibers with a single filament fineness of 3.3 dtex (thickness of 19 μm). SBR resin was sprayed onto this cross web from both sides using a spray method as a binder resin. At this time, the SBR resin was sprayed so that the dry solids content was 30 g / m2. After that, the cross web was dried to prepare a nonwoven fabric base material 12. Next, the nonwoven fabric base material 12 was immersed in a slurry of phenolic resin, which is a synthetic resin adhesive 20, and silicon carbide, which is an abrasive grain 18, adjusted to a solid ratio of 100 / 230, so that the dry solids content was 173 g / m2, to obtain a nonwoven abrasive material 10. Next, 180 pieces of the nonwoven abrasive material 10, cut into 40 x 640 mm rectangular shapes, were compressed by 24% and fixed. The compressed and fixed nonwoven abrasive material 10a was then impregnated with foamed urethane resin, a synthetic resin, and wrapped around the outer surface of the core material 52. By leaving it at room temperature for 12 hours, the nonwoven abrasive materials 10 were fixed and integrated together to produce a polishing roll 50 measuring 150 x 610 x 76.2 mm.

[0026] Using Example 1, Comparative Examples 1 and 2, printed circuit boards were polished under the following conditions, and the congestion between the wiring on the printed circuit boards was checked.

[0027] <Polishing conditions> Object to be polished: Copper foil board: Width 410 x Depth 510 x Board thickness 1.5 mm A test board with a circuit formed on it, where the wiring width / inter-wiring distance is 150 μm / 150 μm. Polishing machine: Surface polishing machine Polishing roll rotation speed: 1800 rpm Feed rate: 3.5 m / min Polishing pressure: 1.5A Cutting direction: Down cut Oscillation: 470 cpm To check for wiring blockage due to worn-out debris, the polishing roll was passed twice under the same conditions as described above, and then wiring blockage was visually inspected. Table 1 shows the results of wiring blockage.

[0028] [Table 1]

[0029] As is clear from Table 1, the number of wiring blockages in Example 1 was reduced by more than 96% compared to Comparative Example 1, and by more than 71% compared to Comparative Example 2. [Explanation of Symbols]

[0030] 10 Non-woven abrasive material 10a Compressed and fixed nonwoven abrasive material 12 Nonwoven fabric base material 14 Synthetic Fibers 16 Binder resin 18 abrasive grains 20 Synthetic resin adhesives 50 abrasive rolls 52 Core material

Claims

[Claim 1] Synthetic fibers are intertwined in three dimensions, and the intertwining points of the synthetic fibers are bonded together with a binder resin. A polishing roll using a nonwoven abrasive material, wherein abrasive particles are dispersed and mixed into a nonwoven base material and fixed using a synthetic resin adhesive, characterized in that the fiber diameter of the synthetic fibers is 50 μm to 88 μm.

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