Multilayer printed circuits

Claim 1

IN THE PROCESS OF MANUFACTURING MULTILAYER PRINTED CIRCUIT BOARDS, EACH BOARD COMPRISING A PLURALITY OF INSULATIVE SHEETS HAVING CONDUCTIVE CIRCUIT PATTERNS THEREON, BONDED TOGETHER TO FORM A PLURALITY OF INSULATED CIRCUIT STRATA BETWEEN EXTERIOR INSULATIVE SURFACES, AND A PLURALITY OF HOLES THERETHROUGH, THE STEPS OF SEEDING SAID EXTERIOR SURFACES AND THE WALLS OF SAID HOLES WITH A THIN FILM OF CONDUCTIVE MATERIAL; COMPLETELY MASKING SAID EXTERIOR SURFACES WITH RIGID INSULATIVE TEMPLATES HAVING RESILIENT SURFACES AND HAVING HOLES CORRESPONDING TO THOSE IN THE BOARD, BY PLACING SAID RESILIENT SURFACES AGAINST SAID SEEDED EXTERIOR SURFACES OF SAID BOARD WITH THE TEMPLATE HOLES DISPOSED IN REGISTRY WITH THE HOLES IN SAID BOARD; MAINTAINING SAID TEMPLATES IN PLACE UNDER PRESSURE TO FORCE SAID RESILIENT SURFACES THEREOF AGAINST SAID SEEDED EXTERIOR SURFACES OF SAID BOARD, THEREBY PREVENTING EXPOSURE OF SAID SEEDED EXTERIOR SURFACES TO PLATING MATERIAL, WHILE ELECTROPLATING THE CONDUCTIVE FILM ON THE WALLS OF SAID HOLES VIA A CONDUCTIVE PATH INCLUDING THE CONDUCTIVE FILM ON SAID SEEDED EXTERIOR SURFACES, TO ELECTRICALLY CONNECTED SAID CIRCUIT STRATA THROUGH A RELATIVELY THICK CONDUCTIVE LAYER; AND REMOVING SAID TEMPLATES AND THE THIN CONDUCTIVE FILM FROM SAID SEEDED EXTERIOR SURFACES TO EXPOSE SAID INSULATIVE EXTERIOR SURFACES WITH PADLESS PLATED THROUGHHOLES THEREBETWEEN.