SOLDER PLATE REFLOW METHOD FOR FORMING A SOLDER BUMP ON A CIRCUIT TRACE

摘要

A solder bump (30, 124) is formed on a circuit trace by a method that includes depositing onto the trace a uniform thin plate (26, 124) of solder alloy and reflowing the solder alloy to form the bump. In one aspect of this invention, the trace comprises first and second linear sections (18, 20) that intersect at an intersection (22) whereat the bump is formed. In another aspect of this invention, the trace includes a terminal (116) having an enlarged terminal pad (118) connected to a runner section (120), whereupon the bump forms at the pad. The solder plate is deposited, preferably by electroplating, at a thickness between about 10 and 25 microns. Thereafter, when the trace is heated to melt the solder layer, the solder coalesces to form the bump having a height preferably greater than 40 microns.