DEFECTS IN OPTOELECTRONIC MATERIALS DUE TO PHOSPHORUS-CONTAINING UNDERLAYER

We report the new observation that the crack formation mechanism in a laser-welded Au-coated optoelectronic material is due to the existence of P-containing underlayer and is not due to the thickness of the Au plating layer. Therefore, to solve the problem of crack formation in l aser-welded Au-coated optoelectronic materials, it is strongly recomme nded that a Ni underlayer with P-free electroplating instead of P-cont aining electroless plating should be used prior to plating Au on optoe lectronic materials.