Polishing device for creating flat surface

Abstract

A polishing device includes a movable base, a polishing head fixed on the movable base and a flatness detecting unit fixed on the movable base. The polishing head polishes a surface of a workpiece under driving of the movable base to achieve complete flatness. The flatness detecting unit moves along with the polishing head, for detecting the flatness of the surface of the workpiece polished by the polishing head.

What is claimed is: 
     
         1 . A polishing device for polishing a surface of a workpiece, comprising:
 a movable base;   a polishing head fixed on the movable base, the polishing head being configured for polishing the surface of the workpiece under driving of the movable base; and   a flatness detecting unit fixed on the movable base, the flatness detecting unit moving along with the polishing head during a polishing process, for detecting a flatness of the surface of the workpiece polished by the polishing head.   
     
     
         2 . The polishing device of  claim 1 , wherein the flatness detecting unit comprises:
 a coherent light source for generating a first light beam with a single frequency;   a light splitting member positioned on an optical path of the first light beam emitted from the coherent light source for splitting the first light beam into a second light beam and a third light beam, the second light beam projected on the polished surface and reflected to the light splitting member again by the polished surface, the second light beam reflected by the polished surface being split into a fourth coherent light by the light splitting member;   a reflector positioned on an optical path of the third light beam for reflecting the third light beam to the light splitting member again, the third light beam reflected by the reflector is split into a fifth coherent light beam having the same transmitting direction as the fourth coherent light beam;   a receiving member positioned on an optical path of the fourth and fifth coherent light beams for receiving an interference pattern of the fourth and fifth coherent light beams; and   an analyzing member electrically connected to the receiving member for analyzing the interference pattern received by the receiving member and determining a flatness of the polished surface according to the interference pattern.   
     
     
         3 . The polishing device of  claim 2 , wherein the optical path of the first light beam emitted from the coherent light source is substantially parallel to the movement direction of the movable base. 
     
     
         4 . The polishing device of  claim 2 , wherein the optical path of the first light beam emitted from the coherent light source is substantially perpendicular to the movement direction of the movable base. 
     
     
         5 . The polishing device of  claim 2 , wherein the reflector is movable relative to the light splitting member for adjusting a phase difference of the fourth and fifth coherent light beams. 
     
     
         6 . The polishing device of  claim 1 , wherein the receiving member is selected from the group consisting of charge-coupled device and complementary metal oxide semiconductor. 
     
     
         7 . The polishing device of  claim 1 , wherein the analyzing member comprises a storage unit and a processor electrically connected to the storage unit, the storage unit stores a number of interference patterns, each interference pattern represents a flatness of a surface, the processor analyses the interference pattern received by the receiving member, compares the received interference pattern to the interference patterns stored in the storage unit, and then determines the flatness of the polished surface of the workpiece. 
     
     
         8 . The polishing device of  claim 7 , wherein the analyzing member computes an adjusting quantity of the polishing head according to the determined flatness, and the adjusting quantity is fed back to the polishing head. 
     
     
         9 . The polishing device of  claim 1 , wherein the coherent light source is a laser generator.