Low Pressure and Short-Time Silver-Sintering for Power Modules

dc.contributor.authorChen, Yanchengen
dc.contributor.committeechairLu, Guo Quanen
dc.contributor.committeememberAning, Alexander O.en
dc.contributor.committeememberTao, Chenggangen
dc.contributor.departmentMaterials Science and Engineeringen
dc.date.accessioned2025-06-10T08:02:24Zen
dc.date.available2025-06-10T08:02:24Zen
dc.date.issued2025-06-09en
dc.description.abstractSilver-sintering has become one of the main chip interconnect technologies in wide bandgap (WBG) semiconductor power modules due to its excellent thermal conductivity, high temperature stability and mechanical reliability. However, the traditional silver sintering process generally has the problems of long sintering time and high auxiliary pressure, which not only restricts the industrial production efficiency, but also may cause mechanical damage to the brittle chip. In this study, an innovative low-pressure and short-time silver sintering process, namely the Paste+Film method, was proposed and systematically verified. Through controlled experiments, the results showed that the Paste+Film method can achieve high-quality silver connections with a shear strength of more than 40MPa under the conditions of only applying a mild pressure of 5–10 MPa and shortening the sintering time to 3–5 minutes. In addition, the process was successfully applied to the packaging preparation of double-sided cooled SiC MOSFET half-bridge modules, and the overall sintering time was shortened by about 75% compared with the traditional method. Electrical testing and mechanical performance evaluation further verified the superiority of the Paste+Film process in ensuring chip structural integrity, improving process yield and material utilization, and provided a new path for achieving large-scale manufacturing of next-generation high-power density and high-reliability power modules.en
dc.description.abstractgeneralElectric vehicles, renewable energy systems, and other modern technologies demand high-power, efficient, and thermally reliable power modules. To meet these needs, advanced chip-attachment techniques are required, especially for handling wide band-gap semiconductors like SiC and GaN. This thesis introduces the Paste+Film method, a silver-sintering approach that combines silver paste with a porous silver film. The paste improves surface contact and acts as an adhesive layer, while the film provides structural rigidity and allows solvent to escape during direct sintering. This dual-layer configuration enables strong bonding under low pressure (5-10 MPa) in just 3-5 minutes, significantly faster and gentler than conventional processes. The method was tested on both Ag-Ag and Au-Ag bonding interfaces. For Ag-Ag connections, a shear strength above 40 MPa was achieved using only 5 MPa of assist pressure and a sintering time of 3 minutes at 240. For Au-Ag connections, a bonding strength of 25 MPa was attained with 10 MPa pressure in 5 minutes at 240. These results highlight the adaptability of the method to different metallization types while ensuring robust joint quality. Applied to double-sided cooled SiC MOSFET power modules, the Paste+Film method reduced total process time by approximately 75% compared to traditional approaches. It protects brittle chips from pressure-induced damage and simplifies manufacturing, offering a practical path toward scalable, high-performance power electronics.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.othervt_gsexam:44133en
dc.identifier.urihttps://hdl.handle.net/10919/135436en
dc.language.isoenen
dc.publisherVirginia Techen
dc.rightsCreative Commons Attribution-NonCommercial 4.0 Internationalen
dc.rights.urihttp://creativecommons.org/licenses/by-nc/4.0/en
dc.subjectsilver-sintering die-attachen
dc.subjectpower electronics packagingen
dc.subjectsilver-sintering pasteen
dc.subjectsilver-sintering filmen
dc.titleLow Pressure and Short-Time Silver-Sintering for Power Modulesen
dc.typeThesisen
thesis.degree.disciplineMaterials Science and Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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