Wiring sheet assemblies, and forming electrical connections thereof.

摘要

A multi-layer wiring assembly comprises a stack (2) of insulating layers (3), e.g. of polyimide, alternating with wiring patterns (4), typically of copper. To establish the circuit pattern, successive wiring patterns (4) are connected to one another through the intervening insulating layers at a plurality of predetermined locations, by metal stud connections (5). The studs (5) are formed during assembly of the stack by wire-bonding a stud onto an underlying wiring pattern through a through-hole (31) of the insulating layer (3) above, and then stamping the exposed end of the wire-bonded stud to spread it into contact with the uppermost wiring pattern (4). The wire-bonded studs (5), e.g. of Au, form strong bonds with the underlying conductor and are quick to apply in an automated process using a wire-bonding machine.