Electroless Ni-P/Pd/Au plating for semiconductor package substrates

Abstract

Since portable electronic equipment has become popular BGAs (ball grid arrays) are increasingly used for semiconductor packages mounted on high-density printed circuit boards. Semiconductor chips and package substrates are connected by gold wire bonding in most BGAs. These package substrates and motherboards are connected by solder balls. To satisfy the reliability required for these connections, gold plating is applied to the terminals on both sides of the package substrate. Electroless gold plating has an advantage in the higher-density package substrates. However, as the reliability of the conventional electroless Ni-P/Au plating was not sufficient, we have developed a new electroless Ni-P/Pd/Au plated coating which ensures adequate reliability.