BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic view of a polishing device with a conventional sheet disclosed in U.S. Pat. No. 5,781,393;
FIG. 2 shows a local schematic view of the sheet of FIG. 1;
FIG. 3 shows a local schematic view of a sheet for mounting the polishing workpiece according to the present invention; and
FIGS. 4 to 6 show schematic views of each process step of the method for making the sheet for mounting the polishing workpiece according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 3, a local diagram schematic view of a sheet for mounting the polishing workpiece according to the present invention is shown. The sheet 2 of the present invention is of a two-layered structure, which comprises a substrate 21 and a surface layer 22. The substrate 21 has a first surface 211 and a second surface 212, wherein the second surface 212 is used for being adhered on the lower base plate (not shown) of a polishing device. In this embodiment, the material of the substrate 21 is high solid PU, with a plurality of continuous or discontinuous type holes 213 existing in the interior of the substrate 21, and the thickness of the substrate 21 can be larger than 0.5 mm. However, it is to be understood that the material of the substrate 21 may also be acrylic resin or another kind of resin.
The surface layer 22 is located on the first surface 211 of the substrate 21, and has a surface 221 and a plurality of through holes 222. The surface layer 22 has no hole structure in the interior thereof. The material of the surface layer 22 is a polymeric elastomer without foam (for example PU, acrylic resin or another kind of resin), and the surface layer 22 has a uniform thickness which is less than that of the substrate 21. The materials of the surface layer 22 and the substrate 21 may be the same or different. The surface 221 of the surface layer 22 is used for carrying and mounting a polishing workpiece (not shown).
When the polishing workpiece contacts the surface 221, the air therebetween may be vented to the substrate 21 via the through holes 222 and then easily vented out, without causing the phenomenon of air wrapping, which increases the adsorption force between the polishing workpiece and the sheet 2, thereby improving the polishing effect of the polishing workpiece. The through holes 222 penetrate the surface layer 22. Preferably, the through holes 222 further extend to the substrate 21. That is, the substrate 21 has a plurality of recesses 214 disposed on the corresponding position of the through holes 222 to be in communication with the through holes 222.
Additionally, since no hole structure exists in the interior of the surface layer 22, the slurry will not be inhaled during the polishing, which can prolong the lifetime of the sheet 2.
The present invention further relates to a method for making the sheet for mounting a polishing workpiece, which comprises the following steps.
At first, referring to FIG. 4, a surface layer 22 is formed on a release paper 30. The surface layer 22 has no hole structure in the interior thereof. The surface layer 22 has a surface 221. The material of the surface layer 22 is a polymeric elastomer without foam (for example PU, acrylic resin or another kind of resin), and the surface layer 22 has a uniform thickness. Preferably, the surface layer 22 is formed on the release paper 30 in a manner of coating.
Then, referring to FIG. 5, a substrate 21 is formed on the surface layer 22, and the substrate 21 has a first surface 211 and a second surface 212. In this embodiment, the material of the substrate 21 is high solid PU, with a plurality of continuous or discontinuous type holes 213 existing in the interior of the substrate 21, and the thickness of the substrate 21 is larger than 0.5 mm. However, it is to be understood that the material of the substrate 21 may also be acrylic resin or another kind of resin. The materials of the surface layer 22 and the substrate 21 may be the same or different. Preferably, the substrate 21 is formed on the surface layer 22 in a manner of coating. Therefore, compared with the conventional wet process, the substrate 21 of the invention can remain a uniform thickness when the thickness thereof is larger than 0.5 mm.
Then, the substrate 21 and surface layer 22 are dried for one day. After that, the release paper 30 is removed.
At last, referring to FIG. 6, after turning the substrate 21 and the surface layer 22 upside-down for 180 degrees, a plurality of through holes 222 is formed on the surface 221 of the surface layer 22 by using a laser 40 with high energy. Preferably, the laser 40 with high energy further forms a plurality of recesses 214 on the substrate 21, so as to form the sheet 2 (the same as FIG. 3).
Preferably, a water repellent treatment may also be performed for the surface layer 22 to prolong the lifetime of the sheet 2.
While several 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 which maintain the spirit and scope of the present invention are within the scope as defined in the appended claims.