Influence Factors of Joule Heating in Microbump in Advanced Packaging Technology

Due to the requirement for high power and multiple functions of consumer electronic products, Joule heating in microbumps in advanced packaging technology becomes increasingly serious, which greatly affects the reliability of the device. In this paper, we quantitively investigated the influence factors of Joule heating in microbumps by both experiments and simulation. Except for current density, increasing the environmental temperature can greatly increase the accumulation of Joule heating in test samples. Besides, increasing the number of microbumps under current stress will also lead to higher Joule heating. In addition, due to the higher resistivity of the intermetallic compound (IMC) compared with solder, the power of Joule heating in a pair of full-IMC microbumps is 12.5% higher than that in the as-fabricated sample. Serious Joule heating will cause the void induced by side wall wetting in the microbump, which, however, was proved to have limited influence on the Joule heating in return. We also found thermomigration (TM) in the unpowered microbump under severe Joule heating because of the different heat dissipation abilities of its upper and lower ends. The paper demonstrated the contributing factors of Joule heating in the microbump and analyzed the reliability consequences that severe Joule heating results in. © 2024 IEEE.