JP6630528B2 - Polishing pad - Google Patents

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 stacked.

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

  In the case of processing a housing or the like of a small portable electronic device having a shape with a change in thickness as described above, it is possible to use a technique of cutting and molding.

  When processing a shape having a change in thickness by cutting, the work 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, an arc-shaped cutting mark is formed on a processing surface according to the ball diameter of the ball end mill. When an R-shaped diamond tool is used, since a plane and a curved surface need to be formed in separate cutting steps, a step is formed at the boundary between the plane and the curved surface, and a uniform surface is machined. I can't. Similarly, when a mold whose thickness is changed by a mold is molded, unevenness which is affected by the surface quality of the mold is formed on the entire surface in contact with the mold.

  Therefore, it is necessary to polish the surface of the work using a polishing pad described in Patent Literature 1 after the cutting as a means for removing cutting marks, steps, and irregularities generated by the cutting or the die molding.

JP 2014-138974 A

  The polishing pad described in Patent Literature 1 is formed as a laminated structure including an elastic pad, a base layer, and an adhesive layer therebetween, and when the work is pressed against the polishing pad, the polishing pad It is configured to deform according to the shape.

  However, when a polishing pad having a laminated structure capable of improving the followability to the shape of the work is used, there has been a problem that the polishing pad is peeled off from the polishing platen or the interlayer of the polishing pad is peeled off. That is, when the work is pressed against the polishing pad having the laminated structure, the polishing surface side of the polishing pad is deformed according to the shape of the work. In this case, the amount of deformation of the polishing pad on the polishing surface side in direct contact with the workpiece is significantly larger than the amount of deformation on the surface opposite to the polishing surface and other portions including the layer located thereunder. Become. Since the workpiece moves on the polishing surface while being pressed against the polishing surface during polishing, as a result, the in-plane or horizontal in-plane stress applied to the polishing becomes significantly stronger than the same-direction stress applied to other portions. Then, the in-plane stress on the polished surface increases with an increase in the rotation speed of the platen and the polishing load, and when the in-plane stress difference between the polished surface and the bottom surface on the opposite side increases, polishing occurs. A force is generated that lifts the edge on the surface side and warps the polishing pad. Then, when the force to deflect the polishing pad is larger than the adhesive strength of the adhesive bonding the layers constituting the polishing pad, the layers constituting the polishing pad are peeled or broken, and the adhesive fixing the polishing pad is formed. If the bonding strength is larger than the edge of the polishing pad, the edge of the polishing pad is peeled off from the surface plate or broken.

  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 prevent the polishing pad from being peeled off from the polishing platen and the interlayer of the polishing pad being peeled off. 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, at least near the edge of the polishing pad on the polishing surface side of the polishing layer more than the cushion layer. And a rigid member having a flexural modulus of a predetermined value joined to the polishing layer.

  According to the present invention thus configured, the rigid member is arranged near the edge of the polishing pad and joined to the polishing layer, so that an in-plane stress is generated on the polishing surface of the polishing layer, and the entire polishing pad and / or Alternatively, even when a warping force is generated in the polishing layer, the warping of the polishing pad and / or the polishing layer can be suppressed by the rigid member having a predetermined value of the bending elastic modulus.

  In the present invention, preferably, the polishing layer has a disk shape, the rigid member has a ring shape having the same outer diameter as the outer diameter of the polishing layer, It is joined on the polishing surface so that the outer periphery of the polishing layer coincides with the outer periphery.

  According to the present invention thus configured, the rigid member can be formed into a ring shape and joined to a disk-shaped polishing layer having the same diameter so that the outer circumferences of the two become the same. Thereby, the rigid member can be joined to the vicinity of the outer periphery of the polishing layer where warpage is likely to occur, and the removal of the polishing layer can be suitably suppressed.

  In the present invention, the cushion layer has a disc shape, and the polishing layer has a disc shape having a smaller diameter than the cushion layer, and the cushion layer and the polishing layer are 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. Is bonded to the outer periphery of the polishing layer so as to surround the outer periphery of the polishing layer.

  According to the present invention thus configured, a ring-shaped rigid member can be joined to a step formed by a cushion layer and a polishing layer having different diameters arranged concentrically. Then, by bonding the rigid member to the outer periphery of the polishing layer, it is possible to suppress the occurrence of warpage of the polishing layer by the rigid member on the outer periphery of the polishing layer where warpage is most likely to occur.

  Further, in the present invention, preferably, the bending elastic modulus of the rigid member is 1500 MPa or more. The flexural modulus is a value measured according to JIS K7171 with a sample size of 40 mm in length, 10 mm in width, and a fulcrum distance of 22 mm. The flexural modulus of the rigid member is measured using a 1 mm thick sample made of the same material as the rigid member used. Other conditions are measured according to JIS K7171.

  According to the present invention having such a configuration, a peeling angle is hardly formed (hard to be turned up) at the time of polishing, so that peeling is less likely to occur during polishing.

  In the present invention, preferably, 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, and thereby the object to be polished can be polished more uniformly.

  As described above, according to the present invention, it is possible to prevent the polishing pad from peeling off from the polishing platen and the interlayer of the polishing pad from peeling 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. It is a longitudinal section of a polish pad by a 1st embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the polishing pad during polishing according to the first embodiment of the present invention. It is a longitudinal section of a polish pad by a 2nd embodiment of the present 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 the polishing pad 3 is applied. First, as shown in FIG. 1, the single-side polishing machine 1 includes a polishing platen 5 on which a polishing pad 3 is fixed on an upper surface. A shaft 7 is provided at the bottom of the polishing platen 5, and the polishing platen 5 is configured to be able to rotate around the axis of the shaft 7. A polishing head 9 is arranged 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 the object to be polished, and the object to be polished is bonded and fixed to the holding plate 11 using wax. 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. And has 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 having a core material of a flexible film such as polyethylene terephthalate (PET) or polypropylene or an adhesive. Then, a surface of the polishing layer 13 on which the adhesive layer 17 is not provided, in other words, a surface of the polishing layer 13 not facing the cushion layer 15 forms a circular polishing surface 19. A double-sided tape 21 for attaching the polishing pad 3 to the polishing platen 5 is attached to the surface of the cushion layer 15 on the side not facing the polishing layer 13.

  The polishing pad 3 includes a rigid member 23 joined 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 equal to 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 value of bending elastic modulus, for example, 1500 MPa or more. 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. Preferably, the thickness of the rigid member 23 and the width of the ring portion are 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 such that its outer diameter 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. Then, when the rigid member 23 is joined to 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 a polishing pressure is applied to the workpiece W during polishing, the workpiece W is pressed against the polishing pad 3. When the work W is pressed against the polishing pad 3, the polishing pad 3 is deformed following the shape of the work W. When the polishing pad 3 is deformed following the shape of the object W to be polished, the amount of deformation of the polishing surface 19 in direct contact with the object W to be polished is, for example, the surface of the polishing pad 3 on the side opposite to the polishing surface 19, In addition, the deformation amount is larger than the deformation amount of the other portion of the polishing pad 3 including both surfaces of the cushion layer 15. Therefore, at the time of polishing, the in-plane stress applied to the polished surface 19 becomes larger than that of other portions, and the difference in the in-plane stress causes the peripheral portion of the polished surface 19 to which no pressure is applied from the workpiece W to be polished. A force for moving the polishing table 5 away from the polishing table 5 is generated. If the polishing pad 3 is warped by this force, the polishing pad 3 may be peeled off from the polishing platen 5 or the polishing layer 13 may be peeled off from the cushion layer 15, so that the polishing pad 3 cannot be used. 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 largest, so that the peripheral portion of the polishing pad 3 can be prevented from warping. By joining the rigid member 23 to the peripheral edge of the polishing pad 3, it is possible to suppress the peripheral edge of the polishing pad 3 from rising during polishing by the rigid member 23 having a predetermined rigidity and a small deformation amount. . Further, by forming the rigid member 23 in a ring shape having a circular outer periphery, it is possible to uniformly suppress the lifting of the peripheral portion. Thus, even when the entire polishing pad 3 and / or the polishing layer 13 warp, the rigid member 23 can prevent the polishing pad 3 and / or the polishing layer 13 from warping.

  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 so as 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 stacked concentrically. A step is formed between the polishing layer 13 and the cushion layer 15. The rigid member 23 is disposed at 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 It is joined to the upper surface of. Thus, 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 at the time of polishing, as in the first embodiment. Lifting can be suppressed. Thus, it is possible to suppress the occurrence of warpage of the polishing layer 13 due to the rigid member 25 on the outer periphery of the polishing layer 13 where warpage is most likely to occur.

  The present invention is not limited to the above-described embodiment, and each configuration in the embodiment can be appropriately changed without departing from the gist of the present invention.

  For example, in the above 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 of the rigid member 23 that contacts the polishing surface 19, so as to enhance the discharge property of the slurry.

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

Claims (3)

A polishing pad formed by laminating a polishing layer and a cushion layer,
A rigid member having a flexural modulus of at least a predetermined value, which is joined to the polishing layer near the edge of the polishing pad on the polishing surface side of the polishing layer at least than the cushion layer,
Flexural modulus of the rigid member state, and are more 1500 MPa,
The polishing layer has a disk shape,
The rigid member has a ring shape having the same outer diameter as the outer diameter of the polishing layer, and is joined to the polishing surface so that the outer periphery of the polishing layer coincides with the outer periphery of the polishing layer. A polishing pad. A polishing pad formed by laminating a polishing layer and a cushion layer,
A rigid member having a flexural modulus of at least a predetermined value, which is joined to the polishing layer near the edge of the polishing pad on the polishing surface side of the polishing layer at least than the cushion layer,
The flexural modulus of the rigid member is 1500 MPa or more,
The cushion layer has a disc shape, and the polishing layer has a disc shape with a smaller diameter than the cushion layer, and the cushion layer and the polishing layer are aligned so that the centers of the both are coincident. Laminated,
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. A polishing pad , which is bonded to an outer periphery. Wherein the polishing surface, a plurality of grooves are formed, a polishing pad according to claim 1 or 2.

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