Abstract
Direct-bonded aluminum (DBA) multi-layer substrates have been fabricated using low-pressure silver sintering. These multi-layer substrates can be used to reduce the peak electric field strength inside power modules. This benefit is particularly important for medium-voltage silicon carbide (SiC) MOSFETs due to their higher operating voltages. The voiding content and defect density of the bond used to create the multi-layer substrate stackup is critical to the thermal performance and reliability of the power module. This work two low-pressure-assisted sintering techniques; one using nano-silver preform and the other using nano-silver paste to bond 23 mm by 49 mm DBA substrates. Scanning acoustic microscopy (C-SAM) is used to evaluate the bond quality after sintering. To evaluate the reliability of the sintered multi-layer substrates, passive thermal cycling from –40 °C to 200 °C was performed. Cross-sections were cut at pre-determined intervals and imaged with Scanning Electron Microscopy (SEM). After 1,000 thermal cycles, minor cracking was observed, but no failures have occurred.
Original language | American English |
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Number of pages | 9 |
State | Published - 2021 |
Event | 2021 IEEE Applied Power Electronics Conference (APEC) - Duration: 9 Jun 2021 → 12 Jun 2021 |
Conference
Conference | 2021 IEEE Applied Power Electronics Conference (APEC) |
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Period | 9/06/21 → 12/06/21 |
NREL Publication Number
- NREL/CP-5400-79563
Keywords
- power module
- preform
- reliability
- silicon carbide
- silver sintering
- stacked substrates