Patent ID: 9125334
Filing Date: 2015-09-01
Classification: H05K,Y10T

Abstract:
1. A method for manufacturing multilayer flexible PCBs, each of the flexible PCBs comprising n circuit layers, n representing an even integer greater than 2, the method comprising the following steps, in the order listed: first, providing a flexible substrate strip wound around two spools, the flexible substrate strip comprising two copper foils and an insulating layer sandwiched between the two copper foils, the flexible substrate strip including a plurality of PCB units connected sequentially along a length direction of the flexible substrate strip, each PCB unit comprising n/2 segments connected along a length direction of the PCB unit, each segment including two copper foil portions; second, forming n−2 copper foil portions of each PCB unit into traces with remaining two copper foil portions of each PCB unit left untreated, in a reel to reel process; third, cutting the flexible substrate strip into pieces along border lines between the PCB units to separate the PCB units from each other; fourth, folding each PCB unit along border lines between the n/2 segments in such a manner that the traces formed from the n−2 copper foil portions are folded and sandwiched between the remaining untreated two copper foil portions; fifth, laminating each folded PCB unit to form a plurality of laminated multilayer substrates; and sixth, forming traces in the remaining untreated two copper foil portions.