METHOD FOR PRODUCING MULTILAYER PRINTED-CIRCUIT BOARDS Russian patent published in 1997 - IPC

FIELD: radio electronics. SUBSTANCE: external layers with pattern of conductors of internal metallization levels and holes in insulation are made of polyamide foiled on one side. Holes are obtained by etching on side of polyamide. Internal layers with pattern of conductors are made. Stack of external and internal layers, and bonding gaskets is assembled, compressed by heating, and through holes are formed. Then holes are metallized simultaneously in external layers and in stack, and pattern of externally-layer conductors is formed as follows. Stack is cleaned, metal coat is deposited on both surfaces of stack and in holes in vacuum. Using photolithography method, pattern of conductor circuit is formed in photoresist layer on either side of stack. Metal coat is deposited by electrochemical method according to pattern in photoresist to desired thickness. Photoresist is removed, blanks are cleaned of metal coating. EFFECT: facilitated procedure. 6 dwg