Pressureless Silver Nanopowder Sintered Bonds for Liquid Cooled IGBT Power Modules

Konferenz: CIPS 2018 - 10th International Conference on Integrated Power Electronics Systems
20.03.2018 - 22.03.2018 in Stuttgart, Deutschland

Tagungsband: ETG-Fb. 156: CIPS 2018

Seiten: 6Sprache: EnglischTyp: PDF

Persönliche VDE-Mitglieder erhalten auf diesen Artikel 10% Rabatt

Autoren:
Kim, Namjee; Li, Rophina; Ng, Wai Tung (The Edward S. Rogers Sr. Electrical and Computer Engineering Department, University of Toronto, Toronto, Ontario, Canada)
Machler, Meinrad; Burgers, John (Electronics/Battery Thermal Management, Dana Canada Corp. Oakville, Ontario, Canada)
Winkler, Sooky (Metallurgy Department, Dana Canada Corp. Oakville, Ontario, Canada)

Inhalt:
An insulated gate bipolar transistor (IGBT) die attachment technique using pressureless silver nanopowder sintering on direct bonded copper (DBC) for liquid cooled heat sink is studied. Henkel (Loctite Ablestik SSP 2020-EN) silver paste is used, and its sintering process is optimized at 200 °C for 60 min with no pressure on the nickel and gold electroplated DBC substrate. A porosity of 29 % is obtained. Irregular shaped particles of micro-meter scale and nano-meter scale sizes are observed via scanning electron microscope (SEM). Differential scanning calorimeter (DSC) / thermogravimetry analysis (TGA) / simultaneous thermal analysis (STA) results indicate that the solvent starts to evaporate at 114 °C and reaches its peak at 133 °C. The temperature for sintering is set at 200 °C to minimize the thermal budget on the fabricated IGBT dies. The isothermal test indicates that a minimum sintering time of 40 min is required to promote sufficient diffusion of atoms. A sintering time of 60 min is found to provide reliable die attachments.