Here is the abstract you requested from the IMAPS_2008 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Study of Suitable Palladium Thickness in ENEPIG Deposits and Comparison of the Deposition Methods for Thick Gold Deposits in ENEPAG Plating|
|Keywords: ENEPIG, Intermetallic, Wirebonding|
|Electroless Ni-P/Pd/Au known by two acronyms: ENEPIG (less than 0.1 µm gold thickness) and ENEPAG (greater than 0.1µm gold thickness) have been used as final finishes in the IC package market. Electroless Ni-P/Pd/Au deposits are known to exhibit excellent solder joint reliability with SAC (SnAgCu) solder alloys and also exhibit stable wire bonding ability. In this paper, it was studied how to maintain thinner intermetallic thicknesses as a function of electroless Pd thickness and solder materials as the purported factors of solder joint reliability. The composition of the intermetallic (IMC) formed was studied by Transmission Electron Microscopy. Additionally, ENEPAG is used for applications requiring gold wire bonding. Two types of electroless gold processes are currently commercially available. The first is a 4 step process including Electroless nickel (EN) + electroless Pd + immersion Au + sulfite-type autocatalytic Au. The other process is contains 3 steps including EN + electroless Pd + cyanide-type autocatalytic Au. The gold surface and gold-stripped Pd surface were examined by Scanning Electron Microscopy. Both thick gold processes were compared for wire bonding ability.|
| Don Gudeczauskas, Technical Director
Uyemura International Corporation