Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Low temperature solid state bonding of Cu-In fine-pitch interconnects

: Bickel, S.; Panchenko, I.; Tachikawa, W.; Wolf, M.J.


Institute of Electrical and Electronics Engineers -IEEE-; International Microelectronics and Packaging Society -IMAPS-:
IEEE 8th Electronics System-Integration Technology Conference, ESTC 2020. Proceedings : September 15th to 18th, 2020, Vestfold, Norway
Piscataway, NJ: IEEE, 2020
ISBN: 978-1-7281-6293-5
ISBN: 978-1-7281-6294-2
ISBN: 978-1-7281-6292-8
Electronics System-Integration Technology Conference (ESTC) <8, 2020, Online>
Conference Paper
Fraunhofer IZM ()

Cu-In fine pitch interconnects are a viable approach for low temperature bonding technologies in 2.5 D and 3D integration. The unique metallurgical phenomena regarding the phase formation and growth of intermetallic compounds (IMCs) in the Cu-In system affect both processing conditions and the resulting interconnection properties. In this work, we investigate the formation Cu-In joints below 150 °C, i.e. in the solid state, under ambient conditions. Dies with Cu interconnects and In caps (25 μm diameter, 55 μm pitch) were bonded in a flip-chip process at moderate pressures and subsequently investigated by means of mechanical testing, cross-sectioning and microstructural analysis. In particular, we reveal the presence of stable interconnects exhibiting a ductile bonding zone. The resulting die shear strengths are in the range of 15-20 MPa.