Study of Long-term Solder Joint and Board-level Reliability Performance of Thin Nickel Plating ENEPIG Laminate LGA Package

Electroless Ni / Electroless Pd / Immersion Gold (ENEPIG) plating method has been established as one of dominant plating methods for substrates in flip chip and System-In-Package assembly. However, there is a serious discoloration problem and reduced productivity for plating thick Ni layer due to its long plating time. This study highlights the benefits of ENEPIG laminate production with thin Ni layer and includes experimental results of long-term solder joint and board-level reliability performance. In addition, using a functional device including a functional silicon die and assembled with thin Ni ENEPIG substrate, a component level reliability test of high-temperature, high-humidity long-term reliability and bias tests such as HTSL, HTOL, Thermal Cycle and Biased Accelerated Moisture were also performed. All reliability test conditions were satisfied and passed without any performance degradation.