LIQUID CRYSTAL POLYMERS FOR CTE MATCHED PWB'S

THIS PROJECT ADDRESSES THE USE OF LIQUID-CRYSTAL POLYMER (LCP) MATERIALS AND PROCESSES TO FARBICATE LAMINATED PRINTED-CIRCUIT BOARDS (PCB) WITH THE IN-PLANE COEFFICIENT OF THERMAL EXPANSION (CTE) MATCHED TO THE CERAMIC-CHIP CARRIERS (6 TO 7 PPM/DEGREES CENTIGRADE) AND THE OUT-OF-PLANE CTE BELOW 30 PPM/DEGREES CENTIGRADE. THIS APPROACH WILL SOLVE THE PROBLEM OF THERMAL-FATIGUE-RELATED FAILURES OF SOLDER JOINTS, ENABLING THE IMPLEMENTATION OF SURFACE-MOUNT TECHNOLOGY IN SPACE FLIGHT ELECTRONICS. ALSO,THIS APPROACH WILL ENABLE THE USE OF RELIABLE MULTILAYER CIRCUITS BY MINIMIZING THERMALLY INDUCED STRESSES ON PLATED,THROUGH-HOLE VIAS. THE RESULT WILL BE PERFORMANCE GAINS (WEIGHT AND VOLUME REDUCTIONS OVER 50 PERCENT BELOW CURRENT DESIGNS), CLOCK SPEED AND MEMORY-SIZE INCREASES, AND RELIABILITY FOR EXTENDED (UP TO 20 YEAR) MISSIONS. IN PHASEI, A UNIQUE FILM EXTRUSION PROCESS, FOLLOWED BY NOVEL POST- PROCESSING TECHNIQUES TO TAILOR THE CTE OF THE LCP CIRCUIT LAYERS, WILL BE USED TO DEMONSTRATE THAT INNOVATIVE MATERIALS AND PROCESSES CAN ELIMINATE THE PROBLEM OF THERMALFATIGUE IN SOLDER JOINTS. IN PHASE II, TECHNIQUES WILL BE DEVELOPED FOR FABRICATING MULTILAYER BOARDS WITH LCPS. THE SOLDER JOINT'S PERFORMANCE AND RELIABILITY ADVANTAGES, AS WELL AS THE COMMERCIAL VIABILITY OF THESE NEW MATERIALS OVERTHE CURRENT STATE OF THE ART, WILL BE DEMONSTRATED. THIS PROJECT ADDRESSES THE USE OF LIQUID-CRYSTAL POLYMER (LCP) MATERIALS AND PROCESSES TO FARBICATE LAMINATED PRINTED-CIRCUIT BOARDS (PCB) WITH THE IN-PLANE COEFFICIENT OF THERMAL EXPANSION (CTE) MATCHED TO THE CERAMIC-CHIP CARRIERS (6 TO 7 PPM/DEGREES CENTIGRADE) AND THE OUT-OF-PLANE CTE BELOW 30 PPM/DEGREES CENTIGRADE. THIS APPROACH WILL SOLVE THE PROBLEM OF THERMAL-FATIGUE-RELATED FAILURES OF SOLDER JOINTS, ENABLING THE IMPLEMENTATION OF SURFACE-MOUNT TECHNOLOGY IN SPACE FLIGHT ELECTRONICS. ALSO,THIS APPROACH WILL ENABLE THE USE OF RELIABLE MULTILAYER CIRCUITS BY MINIMIZING THERMALLY INDUCED STRESSES ON PLATED,THROUGH-HOLE VIAS. THE RESULT WILL BE PERFORMANCE GAINS (WEIGHT AND VOLUME REDUCTIONS OVER 50 PERCENT BELOW CURRENT DESIGNS), CLOCK SPEED AND MEMORY-SIZE INCREASES, AND RELIABILITY FOR EXTENDED (UP TO 20 YEAR) MISSIONS. IN PHASEI, A UNIQUE FILM EXTRUSION PROCESS, FOLLOWED BY NOVEL POST- PROCESSING TECHNIQUES TO TAILOR THE CTE OF THE LCP CIRCUIT LAYERS, WILL BE USED TO DEMONSTRATE THAT INNOVATIVE MATERIALS AND PROCESSES CAN ELIMINATE THE PROBLEM OF THERMALFATIGUE IN SOLDER JOINTS. IN PHASE II, TECHNIQUES WILL BE DEVELOPED FOR FABRICATING MULTILAYER BOARDS WITH LCPS. THE SOLDER JOINT'S PERFORMANCE AND RELIABILITY ADVANTAGES, AS WELL AS THE COMMERCIAL VIABILITY OF THESE NEW MATERIALS OVERTHE CURRENT STATE OF THE ART, WILL BE DEMONSTRATED.