Copper pillar attach substrate

An electronic assembly includes a copper pillar attach substrate (210) that has a dielectric layer (212) and a solder resist layer (230) overlying the dielectric layer (212). The solder resist layer (230) has a plurality of solder resist openings (232). A plurality of parallel traces (214, 220, 222) are formed on the dielectric layer (212). Each trace (214, 220, 222) has a first end portion (262), a second end portion (264) and an intermediate portion (266). The first and second end portions (262, 264) of each trace (214, 220, 222) are covered by the solder resist layer (230), and the intermediate portions (266) are positioned in the solder resist openings (232). Each of the intermediate portions (266) has at least one conductive coating layer (216, 218) on it and has a height measured from the dielectric layer (212) to a topmost one of the at least one conductive coating layer (216, 218) that is at least as great as the solder resist layer (230) thickness.