A Computer-aided Mold Design for Transfer Molding Process in Semiconductor Packaging Industry

This article presents a novel method for the development of a computer-aided mold design for transfer molding process in semiconductor packaging industry. The method developed will standardize mold design process and reduce lead time and costs significantly. In this method, highly robust 3D parametric templates for mold shot for different types of packages are created and stored to constitute a library for computer-aided mold design process. Mold design terms and all related design rules are standardized and streamlined for each mold shot. The mold shot is used to cut out mold parts during the next design stage. Leadframe configurations, customer input as well as technical specifications and design inputs are standardized to create the robust mold shot. Some critical features of mold parts like clamping area, location, and gate dimensions are calculated on mold shot. The mold shot is used as a positive cut-out for the top and bottom cavities as well as cull and sleeve strips. After completion of the cut-out process based on mold shot, air venting for packages and runners, clamping areas, shutoff areas, side-rail areas, relief areas, locating pins holes and their relief, misalignment pins holes and their relief are created by the rules and thumbs and mathematical formulae incorporated into the program. Finally ejection pins, support plugs, springs and other parts are created using parametric parts library and database. A prototype system “PMOLD” is developed based on is new method. This research would make a significant contribution in transfer molding and semiconductor packaging industries.