EFFECTIVE MULTILAYER TESTING.

The importance of a comprehensive test of a computer base printed circuit (PC) board is considered for its increased reliability brought about by-wide-use of LSI and VLSI circuit modules. It is found that comprehensive test approach for short testing a signal core level can reduce the number of shorts defects that will be found in the completed bare cards (after lamination, drilling and plating processes). A signal core test strategy is designed to identify all defects having risk to create shorts at a point in the card manufacturing process where repair is easier and less costly to implement than at bare card. Furthermore, in the case of many defects where repair is not economical, the cost of signal core scrap is less than bare card.