The Study And Realization Of Retest Rate Reduction In Semiconductor Industry

The retest for the rejects in semiconductor industry is a very sensitive topic, currently the retest yield is about 15%-45% in semiconductor company world wide. How to reduce the retest rate, improve the first pass yield and improve the tester utilization caused by the test software, hardware and silicon in ATE are highly concerned by all the people working in this industry to reduce the cost of testing, improve the production profit of the related semiconductor company. Based on this situation, to study the retest rate reduction problem is full of meaningful and significance.This paper is derived from the practical test production projects and performed the analysis for the possible reasons causing the retest issues in the Back End semiconductor industry as well as presented the solutions to the retest issues experienced in the actual practice.The study in this paper for the retest rate reduction were focused on five aspects which cover test program, test load board, wafer fab manufacturing and assembly in back end processes as well as the contact issues, for which was associated with the practical production projects especially for the mixed signal devices testing at production site. The paper makes the further analysis and discussion for all of the topics above. The paper attempts to provide the basic solutions and thoughts for the practical problems of retest typically experienced in the semiconductor manufacturing site to prevent the failures from missing judge due to both the test software and hardware.However, as the speciality of the semiconductor device testing, the basic knowledge for the device testing in ATE i.e. the test environment, test hardware and test software are also introduced as a beginning part of this paper.Semiconductor test technology ATE is under the track of rapid development, but the retest issue is existing accompanied with the development of this industry, However, with the upgrade of the test software and hardware in this industry and with the related engineering people's common efforts we are confident that we could solve the retest issue gradually and eliminate it finally. This is just the right purpose of this paper.