JP2017064861A - Polishing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress peeling between layers constituting a polishing pad and the peeling of the edge of the polishing pad from a polishing surface plate.SOLUTION: A polishing pad formed by laminating a polishing layer and a cushion layer is provided with a rigid member which is joined with the polishing layer in the vicinity of the edge of the polishing pad at least at a polishing surface side from the cushion layer and which has the predetermined value of a bending elastic modulus.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a polishing pad, and more particularly to a polishing pad having a structure in which a polishing layer and a cushion layer are laminated.

  Conventionally, different types of mobile devices such as mobile phones, smartphones, tablet PCs, or various small portable electronic devices such as music players, game devices, or industrial systems are differentiated from other products. In order to achieve this, various shapes are adopted in its appearance and design. In recent years, as a shape of a small portable electronic device, a shape with a change in thickness, such as a shape in which a thickness is reduced toward the outer periphery and a curved surface is formed along the outer periphery, is frequently used. Moreover, by adopting such a shape, in addition to the effect of improving the designability, an information display section or an operation button can be provided on the side surface of the device, thereby improving the degree of freedom of design. be able to.

  And when processing the housing | casing etc. of the small portable electronic device of the shape which gave the change as mentioned above, it is possible to use the technique of cutting and metal mold.

  When machining a shape with a change in thickness by cutting, the workpiece is cut into a predetermined shape using a ball end mill or an R-shaped diamond tool. However, when a ball end mill is used, arc-shaped cutting traces are formed on the processed surface in accordance with the ball diameter of the ball end mill. In addition, when an R-shaped diamond tool is used, it is necessary to form the flat surface and the curved surface by separate cutting processes, so a step is formed at the boundary line between the flat surface and the curved surface, and a uniform surface is processed. I can't. Similarly, when a shape having a change in thickness is formed by a mold, unevenness influenced by the surface quality of the mold is formed on the entire surface that is in contact with the mold.

  Therefore, it is necessary to perform surface polishing of the workpiece using the polishing pad described in Patent Document 1 after the cutting as a means for removing the cutting traces, steps and irregularities generated by the above-described cutting and mold forming.

JP 2014-138974 A

  The polishing pad described in Patent Document 1 is formed as a laminated structure including an elastic pad, a base layer, and an adhesive layer between the two. When the workpiece is pressed against the polishing pad, the polishing pad It is configured to deform following the shape.

  However, when a polishing pad having a laminated structure capable of improving the followability to the shape of the workpiece is used, there is a problem that the polishing pad is peeled off from the polishing surface plate or the layers of the polishing pad are peeled off. That is, when a workpiece is pressed against a polishing pad having a laminated structure, the polishing surface of the polishing pad is deformed according to the shape of the workpiece. In this case, the deformation amount of the polishing pad on the polishing surface side that is in direct contact with the workpiece is significantly larger than the deformation amount on the surface opposite to the polishing surface and other portions including the layer positioned below the polishing surface. Become. Since the workpiece moves on the polishing surface while being pressed against the polishing surface at the time of polishing, the in-plane stress in the in-plane direction or the horizontal direction applied to the polishing is significantly stronger than the stress in the same direction applied to other portions. As the rotational speed of the platen increases and the polishing load increases, the in-plane stress on the polishing surface increases, and the difference in in-plane stress between the polishing surface and the bottom surface on the opposite side increases. A force is generated that lifts the edge on the surface side and warps the polishing pad. Then, when the force that warps the polishing pad becomes larger than the adhesive strength of the adhesive that bonds the layers constituting the polishing pad, the layers that constitute the polishing pad peel off or break, and the adhesive that fixes the polishing pad When it becomes larger than the adhesive strength, the edge of the polishing pad peels off from the surface plate or breaks.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a polishing pad that can suppress the peeling of the polishing pad from the polishing surface plate and the peeling of the interlayer of the polishing pad. And

  In order to solve the above-described problems, the present invention provides a polishing pad formed by laminating a polishing layer and a cushion layer, and at least near the edge of the polishing pad on the polishing surface side of the polishing layer with respect to the cushion layer. And a rigid member bonded to the polishing layer and having a bending elastic modulus of a predetermined value.

  According to the present invention configured as described above, the rigid member is disposed in the vicinity of the edge of the polishing pad and bonded to the polishing layer, whereby in-plane stress is generated on the polishing surface of the polishing layer, and the entire polishing pad and / or Alternatively, even when a force that warps the polishing layer is generated, the polishing pad and / or the polishing layer can be prevented from warping by a rigid member having a predetermined bending elastic modulus.

  In the present invention, preferably, the polishing layer has a disk shape, and the rigid member has a ring shape having the same outer diameter as the outer diameter of the polishing layer, It joins on the said grinding | polishing surface so that a grinding | polishing layer and outer periphery may correspond.

  According to the present invention configured as described above, the rigid member can be formed in a ring shape, and can be joined to a disc-shaped polishing layer having the same diameter so that the outer peripheries thereof coincide with each other. Thereby, a rigid member can be joined to the outer periphery vicinity of the grinding | polishing layer which a warp tends to produce, and it can suppress suitably that a grinding | polishing layer peels.

  In the present invention, the cushion layer has a disc shape, and the polishing layer has a disc shape having a diameter smaller than that of the cushion layer. The cushion layer and the polishing layer are both And the rigid member has a ring shape having the same outer diameter as the outer diameter of the cushion layer and the same inner diameter as the outer diameter of the polishing layer, and the polishing layer The outer periphery of the polishing layer is bonded to the outer periphery of the polishing layer.

  According to the present invention configured as described above, the ring-shaped rigid member can be joined to the step portion formed by the cushion layer and the polishing layer having different diameters arranged concentrically. Further, by joining the rigid member to the outer periphery of the polishing layer, it is possible to suppress the warp of the polishing layer by the rigid member on the outer periphery of the polishing layer that is most likely to be warped.

  Moreover, in this invention, Preferably, the bending elastic modulus of the said rigid member is 1500 Mpa or more. The flexural modulus is a value when the sample size is 40 mm in length, the width is 10 mm, the fulcrum distance is 22 mm, and measured according to JIS K 7171. The bending elastic modulus of the rigid member is measured using a sample having a thickness of 1 mm made of the same material as the used rigid member. About other conditions, it measures based on JISK7171.

  According to the present invention configured as described above, it is difficult to form a peeling angle at the time of polishing (it is difficult to turn).

  In the present invention, it is preferable that a plurality of grooves are formed on the polishing surface.

  According to the present invention configured as described above, the fluidity of the polishing slurry on the polishing surface can be increased, whereby the object to be polished can be more uniformly polished.

  As described above, according to the present invention, it is possible to prevent the polishing pad from being peeled off from the polishing surface plate and the interlayer of the polishing pad from being peeled off.

1 is a perspective view of a single-side polishing apparatus to which a polishing pad according to an embodiment of the present invention is applied. 1 is a longitudinal sectional view of a polishing pad according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of the polishing pad at the time of grinding | polishing by the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the polishing pad by the 2nd Embodiment of this invention.

  Hereinafter, a polishing pad according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a single-side polishing apparatus to which a polishing pad 3 is applied. First, as shown in FIG. 1, the single-side polishing machine 1 includes a polishing surface plate 5 having a polishing pad 3 fixed on the upper surface. A shaft 7 is provided at the bottom of the polishing surface plate 5, and the polishing surface plate 5 is configured to be able to rotate around the axis of the shaft 7. A polishing head 9 is disposed on the polishing pad 3 at a position eccentric from the axis of the shaft 7. The polishing head 9 has a holding plate 11 for holding an object to be polished, and the object to be polished is bonded and fixed to the holding plate 11 using wax. During polishing, the object to be polished is passed through the holding plate 11. Is pressed against the polishing pad 3 to apply a predetermined polishing pressure to the object to be polished.

  FIG. 2 is a longitudinal sectional view of the polishing pad 3 according to the first embodiment of the present invention. As shown in FIG. 2, the polishing pad 3 includes a polishing layer 13 formed of a polyurethane-impregnated nonwoven fabric and a cushion layer 15 formed of a material softer than the polyurethane-impregnated nonwoven fabric constituting the polishing layer 13 such as a polyethylene foam sheet. Are formed as a whole and have a disk shape as a whole. The polishing layer 13 and the cushion layer 15 are bonded to each other via an adhesive layer 17 such as a double-sided tape or an adhesive having a core material of a flexible film such as polyethylene terephthalate (PET) or polypropylene. The surface of the polishing layer 13 on the side where the adhesive layer 17 is not provided, in other words, the surface on the side not facing the cushion layer 15 constitutes a circular polishing surface 19. And the double-sided tape 21 for affixing the polishing pad 3 to the polishing surface plate 5 is affixed on the surface of the cushion layer 15 that does not face the polishing layer 13.

  The polishing pad 3 includes a rigid member 23 bonded to the polishing surface 19 in addition to the polishing layer 13 and the cushion layer 15 described above. The rigid member 23 has a ring shape having an outer diameter substantially the same as the outer diameter of the circular polishing surface 19. The rigid member 23 can be formed using, for example, glass epoxy resin, polyphenylene sulfide, phenol resin, PET, or the like having a predetermined elastic modulus, for example, 1500 MPa or higher. The thickness of the rigid member 23 is preferably 0.5 to 4.0 mm, and the difference between the outer diameter and the inner diameter of the rigid member 23 having a ring shape, that is, the width of the ring portion is 5 to 50 mm. Preferably there is. Note that the thickness of the rigid member 23 and the width of the ring portion are preferably changed according to the thickness of the object to be polished, the diameter of the polishing pad 3, and the polishing pressure.

  The rigid member 23 is joined to the polishing surface 19 so that the outer diameter thereof matches the outer diameter of the polishing surface 19. As a means for joining the rigid member 23 to the polishing surface 19, for example, an adhesive can be used. When the rigid member 23 is joined onto the polishing surface 19 so as to match the outer diameter of the polishing surface 19, a part of the polishing surface 19 is exposed from the inside of the rigid member 23. At the time of polishing, the object to be polished is pressed against a part of the polishing surface 19 exposed from the inside of the rigid member 23 and polished.

  FIG. 3 is a longitudinal sectional view of the polishing pad 3 during polishing. When polishing pressure is applied to the workpiece W during polishing, the workpiece W is pressed against the polishing pad 3. When the workpiece W is pressed against the polishing pad 3, the polishing pad 3 deforms following the shape of the workpiece W. When the polishing pad 3 deforms following the shape of the workpiece W, the amount of deformation of the polishing surface 19 that directly contacts the workpiece W is, for example, the surface of the polishing pad 3 opposite to the polishing surface 19, And the deformation amount of the other part of the polishing pad 3 including both surfaces of the cushion layer 15 is larger. Therefore, at the time of polishing, the in-plane stress applied to the polishing surface 19 is larger than that of other portions, and due to the difference in in-plane stress, the peripheral portion of the polishing surface 19 to which no pressure is applied from the workpiece W, A force for moving in a direction away from the polishing platen 5 is generated. If the polishing pad 3 is warped by this force, the polishing pad 3 may be peeled off from the polishing surface plate 5 or the polishing layer 13 may be peeled off from the cushion layer 15, thereby making the polishing pad 3 unusable. Therefore, in the present embodiment, the rigid member 23 is joined to the peripheral portion of the polishing surface 19 where the in-plane stress difference is the largest, and the warpage of the peripheral portion of the polishing pad 3 can be suppressed. By joining the rigid member 23 to the peripheral portion of the polishing pad 3, it is possible to suppress the peripheral portion of the polishing pad 3 from being lifted by the rigid member 23 having a predetermined rigidity and a small amount of deformation during polishing. . In addition, by making the rigid member 23 into a ring shape whose outer periphery forms a circle, lifting of the peripheral edge can be suppressed uniformly. Thereby, even when the polishing pad 3 as a whole and / or the polishing layer 13 is warped, it is possible to prevent the polishing pad 3 and / or the polishing layer 13 from being warped by the rigid member 23.

  FIG. 4 is a longitudinal sectional view of the polishing pad 3 according to the second embodiment. As shown in FIG. 4, in the polishing pad 3 according to the second embodiment, the upper surface of the rigid member 25 is formed to be flush with the polishing surface 19.

  More specifically, in the polishing pad 3 according to the second embodiment, the polishing layer 13 has an outer diameter smaller than that of the cushion layer 15, and both are laminated concentrically. A step is formed between the polishing layer 13 and the cushion layer 15. The rigid member 23 is disposed in a step between the polishing layer 13 and the cushion layer 15, the inner periphery of the rigid member 25 is joined to the outer periphery of the polishing layer 13, and the bottom surface of the rigid member 25 is the cushion layer 15. It is joined to the upper surface of. In this way, by forming a step between the polishing layer 13 and the cushion layer 15 and joining the rigid member 25 to this step, the peripheral portion of the polishing pad 3 is polished during polishing as in the first embodiment. Lifting can be suppressed. Thereby, it is possible to prevent the polishing layer 13 from being warped by the rigid member 25 on the outer periphery of the polishing layer 13 which is most likely to be warped.

  In addition, this invention is not restricted to the above-mentioned embodiment, Each structure in embodiment can be changed suitably in the range which does not deviate from the meaning of this invention.

  For example, in the above-described embodiment, the polishing surface is illustrated as being flat, but a plurality of grooves for improving the fluidity of the slurry may be formed on the polishing surface. Further, in the polishing pad 3 according to the first embodiment, a groove extending from the inner periphery to the outer periphery may be formed on the surface that contacts the polishing surface 19 of the rigid member 23 so as to improve the slurry discharge performance.

3 Polishing pad 13 Polishing layer 15 Cushion layer 23, 25 Rigid member

Claims (5)

A polishing pad formed by laminating a polishing layer and a cushion layer,
A polishing pad comprising a rigid member bonded to the polishing layer in the vicinity of an edge of the polishing pad at least on the polishing surface side of the polishing layer with respect to the cushion layer and having a flexural modulus equal to or greater than a predetermined value. The polishing layer has a disc shape,
The rigid member has a ring shape having an outer diameter that is the same as the outer diameter of the polishing layer, and is joined on the polishing surface so that the outer periphery coincides with the polishing layer. The polishing pad described in 1. The cushion layer has a disk shape, and the polishing layer has a disk shape having a smaller diameter than the cushion layer, and the centers of the cushion layer and the polishing layer are aligned with each other. Are stacked,
The rigid member has a ring shape having the same outer diameter as the outer diameter of the cushion layer and the same inner diameter as the outer diameter of the polishing layer, and surrounds the outer periphery of the polishing layer so as to surround the outer periphery of the polishing layer. The polishing pad according to claim 1, which is bonded to the outer periphery.   The polishing pad according to claim 1, wherein the rigid member has a flexural modulus of 1500 MPa or more.   The polishing pad according to claim 1, wherein a plurality of grooves are formed on the polishing surface.

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