摘要:
A method of electrolessly gold plating copper on a printed circuit board (PCB). Starting with a copper patterned PCB, steps include: clean with ultrasonic agitation with the PCB initially oriented vertically and gradually moved to a 45° angle; rinse; sulfuric acid bath with ultrasonic and mechanical agitation; rinse; another sulfuric acid bath with ultrasonic and mechanical agitation; plate the copper with palladium with ultrasonic agitation with the PCB initially oriented at a 45° angle and flipped half way through to opposing 45° angle; rinse; post dip in sulfuric acid; rinse; electrolessly nickel plate with mechanical agitation; rinse; nitrogen blow dry; visual inspection for nickel coverage of the copper; hydrochloric acid bath with manual agitation; rinse; if full nickel coverage was not achieved, repeat preceding steps starting with second sulfuric acid bath; gold flash plate to establish a first layer of gold; rinse; autocatalytic gold plate; rinse; and nitrogen blow dry.
摘要:
A semiconductor die adapter assembly includes a semiconductor die cut from a wafer, the die having an active surface including bond pads. A die adapter, also having bond pads, is bonded to the semiconductor die. Die-to-adapter connectors electrically connect the die bond pads to the adapter bond pads. Finally, adapter-to-substrate connectors electrically connect the adapter bond pads to a device substrate. Having bond pads on the die adapter eliminates the need to break and remake the electrical connections to the original bond pads on the die during burn-in testing of the die.