HIGH INTERCONNECT DENSITY SUBSTRATE FOR 3-D PACKAGING

MERIX PROPOSES A NEW METHOD TO MAKE 3-D MULTILAYER COPPER ON KAPTON SUBSTRATES, WHICH CAN PROVIDE A VERY HIGH DENSITY OF INTERCONNECTIONS BETWEEN CLOSELY PACKED CHIPS. THE NEW SUBSTRATE CAN BE USED TO MOUNT CHIPS IN A 2-D ARRAY, AS IN MCM'S, OR IN A 3-D STACKED CHIP ARRAY. CONNECTIONS BETWEEN CHIPS, OR CHIP STACKS, AND SUBSTRATES CAN BE MADE BY SOLDER, BY TAB OR BY WIRE BONDING. THE NEW SUBSTRATES WILL BE MADE BY ADHESIVE BONDING 7 OR MORE CIRCUIT FILMS TO EACH OTHER AND TO A COPPER SUPPORT STRUCTURE. EACH CIRCUIT FILM HAS A 0.8 MIL THICK COPPER CIRCUIT PATTERN FORMED ON A 1 MIL THICK KAPTON SUPPORT FILM. CIRCUIT LINE WIDTHS CAN BE AS SMALL AS 2 MILS ON 4 MIL PITCH. THIS CONSTRUCTION PERMITS THE SAME NUMBER OF INTERCONNECTIONS AS WITH CONVENTIONAL MULTILAYER SUBSTRATES, BUT HAS MAJOR ADVANTAGES IN HEAD TRANSFER, COST, MANUFACTURABILITY, REALIABILITY, RUGGEDNESS AND SIGNAL QUALITY. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS: THIS PROCESS WILL LOWER THE COST OF FASTER, MULTICHIP MODULES.