MY100402A - Injection molded multi - layer circuit board and method of making same. - Google Patents

Abstract

A MULTI-LAYER CIRCUIT BOARD COMPRISED OF TWO OR MORE CIRCUIT BOARD SUBSTRATES (10, 12) SHAPED BY INJECTION MOLDING WITH MATING INTERCONNECTING PINS (22) AND HOLES (26) AND BANDED TOGETHER WITH AN ELECTRICALLY INSULATED ADHESIVE MATERIAL (28). CIRCUIT LEADS (14-20) ARE PROVIDED ON BOTH SIDES OF EACH SUBSTRATE RECESSED INTO CHANNELS FORMED IN THE SURFACE OF THE SUBSTRATE DURING THE MOLDING PROCESS.ELECTRICAL INTERCONNECTION OF THE LAYERS OF CIRCUITRY OCCURS WHERE THE CONDUCTIVE MATERIALS OF THE CIRCUIT LEADS PASSES DOWN THROUGH COMPONENT LEAD HOLE (26) AXIALLY LOCATED IN THE INTERCONNECTING PINS AND AROUND THE EXTERIOR OF THE INTERCONNECTING PINS WHERE CONTACT IS MADE WITH THE CONDUCTIVE MATERIAL COATING ON THE INTERIOR OF THE INTERCONNECTING HOLES.A METHOD OF MAKING THE MULTI-LAYER BOARD INCLUDES INJECTION MOLDING THE SUBSTRATES IN THE SUITABLE SHAPED MOLD (74, 76), PLATING SUBSTANTIALLY ALL OF THE SURFACE OF THE SUBSTRATES WITH THE CONDUCTIVE MATERIAL (82), MASKING WITH A PLATING RESIST (84), PLATING AGAIN WITH CONDUCTIVE MATERIAL (86), PLATING WITH AN ETCH RESISTANT CONTACT MATERIAL (88), REMOVING THE PLATING RESIST AND FLASH-ETCHING TO REMOVE THE CONDUCTIVE MATERIAL INITIALLY PLATED AND MASKED BY THE PLATING RESIST SO AS TO DEFINE THE CIRCUIT LEADS (14-20). THE PREFERRED METHOD USES A ROLLER TO APPLY THE PLATING RESIST TO SOME SURFACES OF THE SUBSTRATES. (FIG.1)