Method for predicting the polishing characteristics and life-span of a soft polishing pad

Abstract

A method for predicting the polishing characteristics and life-span of a soft polishing pad includes the steps of: (a) establishing a matching database by means of performing a series of dynamic analysis tests on a new soft polishing pad by a contact probe at different frequencies and under different loads and detecting the surface reaction of the new soft polishing pad, (b) performing a dynamic analysis test on a to-be-tested soft polishing pad by a contact probe at a predetermined frequency and under a predetermined load and detecting the surface reaction of the to-be-tested soft polishing pad, and (c) comparing the surface reaction data of the to-be-tested soft polishing pad with the matching database and predicting the polishing characteristics and life-span of the to-be-tested soft polishing pad subject to the comparison result. Subject to the aforesaid steps, the polishing characteristics and life-span of the to-be-tested soft polishing pad can be predicted without making an actual polishing test, thereby saving a large amount of time and cost.

1 . A method for predicting the polishing characteristics and life-span of a soft polishing pad, comprising the steps of:
 (A) preparing a new soft polishing pad having polishing characteristics that are known, and then performing a series of dynamic analysis tests to oscillate said new soft polishing pad with contact probe at different oscillation frequencies and under different loads, and then detecting the surface reaction of said new soft polishing pad during every dynamic analysis test, and then using the tested data and the known polishing characteristics of said new soft polishing pad to establish a matching database;   (B) preparing a to-be-tested soft polishing pad for polishing a predetermined workpiece and then performing a dynamic analysis test to oscillate said to-be-tested soft polishing pad at a predetermined oscillation frequency and under a predetermined load and then detecting the surface reaction of said to-be-tested soft polishing pad during the dynamic analysis test; and   (C) comparing the surface reaction of said to-be-tested soft polishing pad with the data of said matching database to predict the polishing characteristics and life-span of said to-be-tested soft polishing pad.   
     
     
         2 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 1 , wherein the dynamic analysis tests performed in step (A) and step (B) are to apply a cyclic stress to the surface of said new soft polishing pad or said to-be-tested soft polishing pad perpendicularly when said new soft polishing pad or said to-be-tested soft polishing pad is being oscillated. 
     
     
         3 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 2 , wherein said cyclic stress is applied to the surface of said new soft polishing pad or said to-be-tested soft polishing pad through a contact probe, said contact probe having a geometric shape predetermined subject to the configuration of the surface asperities of said predetermined workpiece. 
     
     
         4 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 1 , wherein detecting the surface reaction of said new soft polishing pad during step (A) and detecting the surface reaction of said to-be-tested soft polishing pad during step (B) are done by means of using a pressure sensor to measure the surface reaction force of said new soft polishing pad and said to-be-tested soft polishing pad. 
     
     
         5 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 1 , wherein the predetermined loads during step (A) and step (B) include static loads and dynamic loads. 
     
     
         6 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 5 , wherein the value of the static load applied during step (B) is determined subject to the pressure to be applied to said to-be-tested soft polishing pad during an actual polishing process. 
     
     
         7 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 5 , wherein the value of the dynamic load applied during step (B) is determined subject to the pressure to the average height of the surface asperities of said predetermined workpiece. 
     
     
         8 . The method for predicting the polishing characteristics and life-span of a soft polishing pad as claimed in  claim 1 , wherein the value of the oscillation frequency set during step (B) is determined subject to the distribution density of the surface asperities of said predetermined workpiece.