Here is the abstract you requested from the IMAPS_2013 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.
|Copper wirebond compatibility with organic and inorganic ions present in mold compounds|
|Keywords: Molding compounds, Copper Wirebonding, CuWB Corrosion|
|Abstract: Copper wirebonded (CuWB) packaging is emerging as a replacement to gold wire technology with continuously increasing gold price. As copper is more susceptible to corrosion than inert gold there are several reliability concerns especially the integrity of Cu-Al interface. Copper wirebond compatibility with surrounding encapsulating mold compound is of critical importance as this matrix can produce a corrosive environment in the presence of moisture and ionic impurities. Mold compounds consist of different chemical components which can yield several ionic species of organic and inorganic nature in presence of absorbed moisture. Even though the effect of chloride on CuWB reliability is presented in various publications, the impact of other ions typically present in mold compound matrix is not widely discussed. It is important to understand the role of these ions on the CuWB reliability to design appropriate mold compounds for product encapsulation as some of the ions are corrosive while others are of benign or beneficial in nature. This paper examines the impact of organic anions such as formate, acetate and oxalate and inorganic anions phosphate and nitrites on CuWB reliability, especially the integrity of the vulnerable Cu-Al interface. As corrosion depends on the pH conditions of the mold compound matrix in presence of moisture, Cu-Al integrity under various pH conditions and ionic concentrations will be presented. Effect of these ions on the corrosive behavior of chloride will be examined. Combined influences of different anions on the Cu-Al integrity will be discussed. A relatively simple method to examine the integrity of the Cu-Al interface will also be described.|
Freescale Semiconductor, Inc.