Patent ID: 6352634
Filing Date: 2002-03-05
Classification: B23K,B32B,H01L

Abstract:
A method for the manufacture of a leadfree substrate comprising:electroplating an intermediate layer comprising nickel or nickel alloy onto a basic body made of copper or copper base alloy to form a nickel plated basic body; and electroplating a solder layer comprising at least two uppermost separate layers onto at least one portion of said nickel plated basic body to form the leadfree substrate, wherein said at least two uppermost separate layers are made of different metals selected from the group consisting of silver, silver alloy, palladium, palladium alloy, gold and gold alloy, and wherein one of the uppermost separate layers is made of silver or silver alloy and wherein the other uppermost separate layer is made of gold or gold alloy, wherein the final uppermost separate layer is deposited in a thickness ranging from 0.3 micrometers to 2.5 micrometers.