TY - CHAP A1 - Bhogaraju, Sri Krishna A1 - Schmid, Maximilian A1 - Liu, E A1 - Saccon, Rodolfo A1 - Elger, Gordon A1 - Klassen, Holger A1 - Müller, Klaus A1 - Pirzer, Georg T1 - Low cost copper based sintered interconnect material for optoelectronics packaging T2 - 2022 IEEE 72nd Electronic Components and Technology Conference (ECTC) UR - https://doi.org/10.1109/ECTC51906.2022.00270 KW - Cu sintering KW - flakes KW - PEG600 KW - reliability KW - encapsulation KW - oxidation KW - transient thermal analysis KW - Scanning acoustic microscopy KW - μ-Raman spectroscopy Y1 - 2022 UR - https://doi.org/10.1109/ECTC51906.2022.00270 SN - 978-1-6654-7943-1 SP - 1720 EP - 1725 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Schwan, Hannes A1 - Mohan, Nihesh A1 - Schmid, Maximilian A1 - Saha, Rocky Kumar A1 - Klassen, Holger A1 - Müller, Klaus A1 - Elger, Gordon T1 - Sintering for High Power Optoelectronic Devices JF - Micromachines N2 - Residual-free eutectic Au80Sn20 soldering is still the dominant assembly technology for optoelectronic devices such as high-power lasers, LEDs, and photodiodes. Due to the high cost of gold, alternatives are desirable. This paper investigates the thermal performance of copper-based sintering for optoelectronic submodules on first and second level to obtain thermally efficient thin bondlines. Sintered interconnects obtained by a new particle-free copper ink, based on complexed copper salt, are compared with copper flake and silver nanoparticle sintered interconnects and benchmarked against AuSn solder interconnects. The copper ink is dispensed and predried at 130 °C to facilitate in situ generation of Cu nanoparticles by thermal decomposition of the metal salt before sintering. Submounts are then sintered at 275 °C for 15 min under nitrogen with 30 MPa pressure, forming uniform 2–5 µm copper layers achieving shear strengths above 31 MPa. Unpackaged LEDs are bonded on first level using the copper ink but applying only 10 MPa to avoid damaging the semiconductor dies. Thermal performance is evaluated via transient thermal analysis. Results show that copper ink interfaces approach the performance of thin AuSn joints and match silver interconnects at second level. However, at first level, AuSn and sintered interconnects of commercial silver and copper pastes remained superior due to the relative inhomogeneous thickness of the thin Cu copper layer after predrying, requiring higher bonding pressure to equalize surface inhomogeneities. UR - https://doi.org/10.3390/mi16101164 Y1 - 2025 UR - https://doi.org/10.3390/mi16101164 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-64984 SN - 2072-666X VL - 16 IS - 10 PB - MDPI CY - Basel ER -