In a semiconductor device which has a base film sheet to support a semiconductor chip in a center region of the base film sheet, a plurality of via holes are formed within a peripheral region of the base film sheet. The via holes may be used to mount a metal plate on the base film sheet or to support...http://www.google.com.au/patents/US5763939?utm_source=gb-gplus-sharePatent US5763939 - Semiconductor device having a perforated base film sheet
