Effect of Fatigue Crack Network in Die-attach Joints on Thermal Resistance

Konferenz: PCIM Asia 2022 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
26.10.2022 - 27.10.2022 in Shanghai, China

Tagungsband: PCIM Asia 2022

Seiten: 5Sprache: EnglischTyp: PDF

Autoren:
Ochi, Koki; Hanada, Ryuichiro (Power Device Works, Mitsubishi Electric Corporation, Japan)
Yokoyama, Yoshinori; Izuo, Shinichi; Nishikawa, Kazuyasu (Advanced Technology R&D Center, Mitsubishi Electric Corporation, Japan)
Kanai, Hiroki; Abe, Yoshiki (Graduate School of Shibaura Institute of Technology, Japan)
Kariya, Yoshiharu (Department of Materials Science and Engineering, Shibaura Institute of Technology, Japan)

Inhalt:
We evaluated the effect of fatigue crack networks in die-attach joints on the thermal resistance Rth and found singular rise of Rth in the final phase of fatigue crack networks formation. Structure of samples was Si/Solder/Si joints, and Sn-based lead-free solder alloys were used for the die-attach materials. We conducted thermal cycling tests and measured Rth, vertical crack density and thickness of die-attach joints before/after the tests. Then, we calculated rise of Rth due to vertical cracks and found that increase of measured Rth became twice larger than calculated one in the final phase of fatigue crack networks formation. Horizontal cracks were observed in cross-sections of a severely damaged sample in addition to vertical cracks, and this caused remarkable rise of Rth.