Patent ID: 7429400

Claim:
A method of reducing solder mask interface attack in a process of fabricating printed circuit boards comprising the steps of: a) providing a printed circuit board comprising a layer of copper or copper alloy and a layer of solder mask on said layer of copper or copper alloy such that there is an interface between said layer of copper or copper alloy and said layer of soldermask; b) treating the printed circuit board with an immersion plating solution, wherein the printed circuit board is treated by immersing the printed circuit board in an immersion plating solution, while simultaneously applying ultrasonic vibrations to the printed circuit board such that the amount of galvanic attack at said interface is reduced, when compared with the same process but without applying ultrasonic vibrations; wherein the immersion plating solution comprises a silver immersion plating solution and wherein the ultrasonic vibrations are applied at a frequency of between about 40 and 80 kHz.