CORRELATION OF SOLDER JOINT MEASUREMENTS TO PROCESS VARIABLES FOR STATISTICAL PROCESS CONTROL

THIS PROGRAM WILL INVESTIGATE THE RELATIONSHIP BETWEEN PRINTED CIRCUIT BOARD ASEMBLY EQUIPMENT PROCESS VARIABLES AND THE GEOMETRIC CHARACTERISTICS OF SOLDER JOINTS TO DEVELOP A BASELINE FOR STATISTICAL PROCESS CONTROL. IT IS GENERALLY ACCEPTED THAT A NUMBER OF UPSTREAM PROCESS VARIABLES IMPACT THE GEOMETRY AND, THEREFORE, THE PERFORMANCE OF CIRCUIT OARD SOLDER JOINTS. A CLEAR DEFINITION OF THIS RELATIONSHIP, HOWEVER, HAS NOT YET BEEN DEVELOPED DUE TO THE UNAVAILABILITY OF ACCURATE DIMENSIONAL MEASUREMENTS OF SOLDER JOINT GEOMETRY. RECENT BREAKTHROUGHS BY RVSI IN THREE-DIMENSIONAL MACHINE VISION TECHNOLOGY HAVE ALLOWED, FOR THE FIRST TIME, HIGH RESOLUTION MEASUREMENTS OF SOLDER GEOMETRY, CREATING THE OPPORTUNITY TO DEVELOP A DEFINITIVE CORRELATION BETWEEN UPSTREAM PROCESS VARIABLES AND DOWNSTREAM SOLDER JOINT CHARACTERISTICS. WITH THIS NEW UNDERSTANDING, A REAL-TIME SOLDER PROCESS CONTROL SYSTEM COULD BE IMPLEMENTED, ALLOWING A REDUCTION IN PRINTED CIRCUIT BOARD DEFECTS. THE PROPOSED PROGRAM WOULD BEGIN THE EFFORT NECESSARY TO CREATE SUCH A CIRCUIT BOARD PROCESS CONTROL SYSTEM BY PROVIDING CIRCUIT BOARD PRODUCTION EQUIPMENT VARIABLES AND THE QUALITY OF THE FINISHED PRODUCT.