Patent Application
20080188168
1. Field of the Invention
The present invention relates to a polishing material and a method for making the same, and more particularly to a polishing material having polishing particles and a method for making the same.
2. Description of the Related Art
Generally, polishing refers to grinding a rough surface through a chemical mechanical polishing (CMP) process. Particularly, a polishing slurry having polishing particles is uniformly distributed on a surface of a polishing pad, and meanwhile, a workpiece to be polished bears against the polishing pad, then, a repeated and regular rubbing operations are performed. The workpiece to be polished includes, for example, a semiconductor, a storage medium substrate, an integrated circuit, an LCD flat glass, an optical glass, or a photoelectric panel, etc.
Similarly, when polishing a workpiece to be polished (not shown), a polishing slurry containing polishing particles is applied between the workpiece to be polished and the polishing pad 2, so as to enhance the polishing effect. Although the polishing pad 2 has the polishing particles 233, the main body of the polishing structure 232 is a PU material with independent foam, and the polishing particles 233 exist in the individual holes of the polishing structure 232, and thus the polishing particles 233 have no fluidity. During the polishing process, the polishing particles 233 on the surface of the polishing structure 232 directly contact the surface of the workpiece to be polished, or after the polishing structure 232 has been polished for a period of time, the polishing particles 233 within the polishing structure 232 are exposed and directly contact the surface of the workpiece to be polished, thus causing the surface of the polished workpiece to be scratched.
Consequently, there is an existing need for providing a polishing material having polishing particles and a method for making the same to solve the above-mentioned problems.
One objective of the present invention is to provide a polishing material having polishing particles. The polishing material having polishing particles comprises a base material, a plurality of polishing particles, and a high polymer elastic body. The base material has a plurality of fibers for defining a plurality of grid-spaces. The polishing particles are distributed in the grid-spaces. The high polymer elastic body covers the base material and the polishing particles.
Another objective of the present invention is to provide a method for making a polishing material having polishing particles, which comprises: (a) providing a base material having a plurality of fibers for defining a plurality of grid-spaces; (b) immersing the base material in a high polymer solution containing a plurality of polishing particles, such that the polishing particles are distributed in the grid-spaces; and (c) solidifying the high polymer solution attached to the base material to form a high polymer elastic body that covers the base material and the polishing particles.
By using the polishing material having polishing particles and the method for making the same of the present invention, the polishing particles are uniformly distributed on the surface of the workpiece for being polished during the polishing process. Therefore, the polishing material having polishing particles and the method for making the same of the present invention is capable of solving the problem of the reduced polishing effect and the pollution of the used polishing slurry caused by the conventional polishing material without containing polishing particles that the polishing particles in the polishing slurry are not uniformly distributed during the polishing process.
Moreover, the base material of the present invention prevents the polishing particles from directly contacting the polished workpiece, thus solving the problem of the surface of the polished workpiece to be scratched caused by the conventional polishing material as an independent foam material that the polishing particles are existed in the independent holes and have no fluidity. Moreover, the base material of the present invention also provides an effect for sweeping the small grinded pieces.
The present invention provides a polishing material having polishing particles. The polishing material is applied in a chemical mechanical polishing (CMP) process for grinding or polishing a workpiece to be polished. The workpiece to be polished includes, but not limited to, a semiconductor, a storage medium substrate, an integrated circuit, an LCD flat glass, an optical glass, and a photoelectric panel, etc.
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After the polishing material 3 having polishing particles is formed, the first surface 301 is first polished to obtain a relatively even surface, which ensures that the successively trimmed second surface 302 has a more preferred evenness, i.e., the polishing material 3 having polishing particles has a consistent thickness, and thus, the stress applied on the surface of the workpiece to be polished by the polishing material 3 having polishing particles during the polishing process is relatively uniform, so that a more even polished surface is produced. Moreover, since the high polymer elastic body 34 is a harder material compared with the fibers 311 of the base material 31, when the second surface 302 is trimmed, a part of the high polymer elastic body 34 of the second surface 302 is removed first, such that part of the fibers 311 is exposed on the second surface 302 of the polishing material 3 having polishing particles.
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The polishing material 3 having polishing particles has a first surface 301 and a second surface 302 corresponding to the first surface 301, and part of the fibers 311 is exposed on the second surface 302 of the polishing material 3 having polishing particles. Therefore, the exposed fibers 311 prevent the polishing particles 32 from directly contacting the polished workpiece (not shown), and thus solving the conventional problem of the surface of the polished workpiece to be scratched caused by that the polishing particles of the polishing material with independent foam are existed in the independent holes and have no fluidity.
Moreover, according to the present invention, the fibers 311 exposed on the second surface 301 also provides an effect of sweeping the small grinded pieces, and solves the problem of the pollution caused by the used polishing slurry. In the embodiment, the polishing material 3 having polishing particles further comprises a plurality of grooves 303 formed on the second surface 302, and depending upon various applications, the grooves 303 may have a geometrical shape of triangle, square, or rectangle. The grooves 303 are formed to make the particles in the polishing slurry be more uniformly distributed, and by using the polishing particles 32 of the polishing material 3 together, a more preferred polishing effect can be achieved.
The polishing particles 32 are distributed in the grid-spaces 312. In the embodiment, the polishing particles 32 are selected from a group consisting of ceria, silicon dioxide, aluminum oxide, yttria, ferric oxide, or a combination thereof. Preferably, the diameter of the polishing particles 32 falls between 0.01 μm and 10 μm, such that the polishing particles 32 are uniformly distributed in the grid-spaces 312 defined by the fibers 311, and a preferred polishing efficiency is achieved during the polishing process.
The high polymer elastic body 34 covers the base material 31 and the polishing particles 32, so as to form the polishing material 3 having polishing particles. In the embodiment, the high polymer elastic body 34 is selected from polypropylene (PP), polyester (PET), or polyurethane resin, and the high polymer elastic body 34 is a continuous foam body.
The polishing particles 32 of the present invention are uniformly distributed within and on the polishing material 3, thus a preferred effect of uniformly covering the polished surface is achieved during the polishing process. Furthermore, the base material 31 prevents the polishing particles 32 from directly contacting the polishing workpiece, so as to prvent the polishing workpiece from being scratched, and also provides an effect of sweeping the small grinded pieces.
While the embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by those skilled in the art. The embodiments of the present invention are therefore described in an illustrative but not restrictive sense. It is intended that the present invention may not be limited to the particular forms as illustrated, and that all modifications that maintain the spirit and scope of the present invention are within the scope as defined in the appended claims.
