Planning for Implementation of Positive Liquid Inner Layer Photoresists

摘要

Planning forImplementation of Positive Liquid Inner Layer Photoresists Positive working photoresists have already long been dominant in the manufacture of semiconductor devices, and have replaced negative working resists due to the improved lithographic performance. Motivated by a need to reduce manufacturing costs, positive working liquid resist are now finding increasing use in the manufacture of Printed Wiring Boards, in particular for innerlayers. Proper planning for the implementation of positive liquid photoresist in an innerlayer production process, is an essential condition for success. The complete photo imaging process, i.e. from copper clad quality and cleaning, through resist application and drying, the exposure, development, etching and stripping process, inclusive the necessary production equipment, phototools, and the involved personnel, has to be at optimum performance for best production results. These results are typically expressed by the 'First-Pass-Yields' (FPY). A FPY of 80