Multilayer printed circuit board with solder access apertures

Claim 1

IN AN ELECTRONIC CIRUCIT, A SELF-SUPPORTING STACK OF CURCUIT BOARDS OF THERMO-SETTING PLASTIC MATERIAL SECURED TO EACH OTHER, EACH OF THE CIRCUIT BOARDS INCLUDING CONDUCTORS HAVING ENLARGED PORTIONS FORMING TERMINAL PADS EMBEDDED AT DIFFERENT LEVELS OF DEPTH IN THE STACK; AT LEAST SOME OF SAID BOARD HAVING ACCESS APERTURES EACH OF WHICH EXTENDS FROM ONE SURFACE OF THE STACK THROUGH THE NUMBER OF RESPECTIVE INTERMEDIATE BOARDS TO ONE SURFACE OF ONE OF SAID TERMINAL PADS FORMING PORTS DEFINED EXCLUSIVELY BY THE PAD AND THE CIRCUIT BOARD MATERIAL FORMING THE APERTURE SIDE WALLS, SAID APERTURES BYPASSING INTERMEDIATE CONDUCTORS ON INTERMEDIATE BOARDS AT INTERMEDIATE LEVELS OF DEPTH, AT LEAST TWO OF SAID APERTURES EXTENDING TO AT LEAST TWO RESPECTIVELY DIFFERENT TERMINAL PADS LOCATED AT DIFFERENT LEVELS OF DEPTH IN THE STACK, SAID PADS AT LEAST PARTLY EXTENDING BEYOND THE AREA OF THEIR ACCESS APERTURE AND INTO THE AREA BETWEEN TWO OF SAID BOARDS AND HAVING AN EXPOSED SURFACE SUFFICIENTLY LARGE TO PERMIT SECURING LEAD WIRES TO THE TEMRINAL PAD, REGARDLESS OF SAID DEPTH.