| Polishing pad and method of producing same -> Monitor Keywords |
|
|
  Polishing pad and method of producing sameUSPTO Application #: 20070010175Title: Polishing pad and method of producing same Abstract: The present invention relates to a method of producing a polishing pad, comprising steps of: (a) providing a base material comprising a plurality of fibers; said base material having a surface for polishing a substrate; (b) impregnating the surface of the base material with an elastomer solution; (c) curing the elastomer impregnated in the surface of the base material to form a plurality of first continuous pores embedded in the elastomer and fibers; (d) impregnating the surface of the base material and elastomer obtained in the step (c) with a condition polymer solution; and (e) curing the condition polymer impregnated in the surface of the base material and elastomer and partially filling the condition polymer into the first continuous pores to form a plurality of second continuous pores. (end of abstract) Agent: Sughrue Mion, PLLC - Washington, DC, US Inventors: Chung-Chih Feng, I-Peng Yao, Yung-Chang Hung USPTO Applicaton #: 20070010175 - Class: 451041000 (USPTO) Related Patent Categories: Abrading, Abrading Process, Glass Or Stone Abrading The Patent Description & Claims data below is from USPTO Patent Application 20070010175. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a polishing pad for use in a chemical mechanical polishing, and a method for producing the polishing pad. [0003] 2. Description of the Related Art [0004] Chemical mechanical polishing (CMP) is a procedure for planarizing the surface of a substrate with a polishing pad. CMP is generally applied in polishing lens, mirrors, substrates of liquid crystal displays, silicon wafers, and oxidation and/or metal layers on silicon wafers. [0005] U.S. Pat. No. 6,454,634 discloses a polishing pad produced by a method comprising the steps of pouring thermoplastic foam resin in a circular mold to form a casting, skiving the casting into sheets, and mechanically machining macro-channels into the surface of the sheets. The polishing pad comprises a polymeric matrix made of polyurethane and hollow elastic polymeric micropheres are distributed therein. The cell size and distribution in the polishing pad made of thermoplastic foam resin highly depend on the distribution of each component in a mixture for molding and also depend on the distribution of temperature of the circular mold. It is difficult to even out the distribution of each component in a mixture for molding in a circular mold. Furthermore, because of viscoelastic property of polyurethane, a knife used in a skiving step cannot be located on the edge of the sheet precisely and subsequently influences the flatness, size and distribution of the cells. These factors reduce the batch uniformity when producing the polishing pad, and thus a polishing process involved becomes complicated. In another aspect, the cells of the polishing pad in this patent are discontinuous for each other, so that polishing fluid cannot flow smoothly and polishing particles cannot diffuse evenly. Besides, the residues formed during polishing easily stay on the surface of the polishing pad and their removal is poor; as a result, the residues scrap and damage the substrate to be polished. [0006] U.S. Patent Application Publication No. 2004/0224623 A1 discloses a polishing pad having a plate-like shape. The polishing pad comprises fibers and a resin fixing the fibers to form the plate-like shape. The polishing pad has at least one surface layer that is substantially non-porous and comprises organic fibers and a resin fixing the organic fibers. A surface of the surface layer of the polishing pad is mechanically polished, so that the surface layer has a surface on which the organic fibers are exposed. This application also discloses layering a resin-impregnated sheet-form fiber base material and a resin-unimpregnated sheet-form fiber base material and unifying them by thermocompression molding to form a polishing pad. However, the thermocompression molding step easily leads to uneven space formed between the layers. As a result, hardness, flatness, compression ratio, elasticity, and recovery ratio of the surface of the polishing pad are all affected. The density variation of the layers thermocompression molded occurs during molding. Besides, the method of producing with the condition at high temperature (such as 300.degree. C.) and high pressure (such as 196 kN/m) chars and hardens the surface of the polishing pad, and then the polishing pad scraps and damages the substrate to be polished. Furthermore, when producing the polishing pad, migration easily occurs and the polymers cannot be distributed in the sheet-form fiber base evenly. Heat for laminating also affects the quality, such as hardness, elasticity, compression rate, and density of the polishing pad. The factors all reduce the efficiency of polishing. SUMMARY OF THE INVENTION [0007] One object of the present invention is to provide to a method of producing a polishing pad, comprising the steps of: [0008] (a) providing a base material comprising a plurality of fibers; said base material having a surface for polishing a substrate; [0009] (b) impregnating the surface of the base material with an elastomer solution; [0010] (c) curing the elastomer impregnated in the surface of the base material to form a plurality of first continuous pores embedded in the elastomer and fibers; [0011] (d) impregnating the surface of the base material and elastomer obtained in step (c) with a condition polymer solution; and [0012] (e) curing the condition polymer impregnated in the surface of the based material and elastomer and partially filling the condition polymer into the first continuous pores to form a plurality of second continuous pores. [0013] Another object of the present invention is to provide a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of fibers, at least one elastomer and at least one condition polymer, and a plurality of continuous pores are embedded in the fibers, elastomer and condition polymer. [0014] A further object of the present invention is to provide a method of polishing a substrate comprising using a polishing pad to polish a surface of the substrate, wherein the polishing pad comprises a base material having a surface for polishing the substrate, wherein the surface comprises a plurality of fibers, at least one elastomer and at least one condition polymer, and a plurality of continuous pores are embedded in the fibers, elastomer and condition polymer. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 illustrates views under a transmission electron microscope of a semi-product (1)(a) and a polishing pad (2)(b). DETAILED DESCRIPTION OF THE INVENTION [0016] The present invention provides a method of producing a polishing pad, comprising the steps of: [0017] (a) providing a base material comprising a plurality of fibers; said base material having a surface for polishing a substrate; [0018] (b) impregnating the surface of the base material with an elastomer solution; [0019] (c) curing the elastomer impregnated in the surface of the base material to form a plurality of first continuous pores embedded in the elastomer and fibers; [0020] (d) impregnating the surface of the base material and elastomer obtained in the step (c) with a condition polymer solution; and Continue reading... Full patent description for Polishing pad and method of producing same Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Polishing pad and method of producing same patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Polishing pad and method of producing same or other areas of interest. ### Previous Patent Application: Fixed abrasive pad having different real contact areas and fabrication method thereof Next Patent Application: Stone fabrication scheme Industry Class: Abrading ### FreshPatents.com Support Thank you for viewing the Polishing pad and method of producing same patent info. IP-related news and info Results in 10.33685 seconds Other interesting Feshpatents.com categories: Accenture , Agouron Pharmaceuticals , Amgen , AT&T , Bausch & Lomb , Callaway Golf |
||
