The massive development of Hybrid and Electrical Vehicles (HEV) is strongly impacting the semiconductor industry demanding for highly reliable Power Electronic components. Within the engine compartment installation space is of major concern, therefore small size and high integration level of the modules are needed. Conventionally devices are typically soldered to ceramics substrates that are vacuum soldered to water-cooled base plates. The known reliability limitations of traditional solder joints are significantly limiting the power density increase, limiting the maximum operative temperature and representing a strong constrain for using high performances devices such as wide bandgap compound like Silicon Carbide (SiC). Silver sintering today has started to replace the solder joint from chips to carrier substrates, leaving one major reliability bottleneck. Combining properly temperature, time and pressure, a strong, highly electrically and thermally conductive bond is formed. The aim of this work is to develop an integrated methodology, numerical and experimental, to assess the Ag sintering die attach process for a SiC power MOSFET. Different process parameters have been benchmarked by means of physical analyses, performed at time zero and also after liquid-to-liquid thermal shock aging test. The sintering flakes densification process has been reproduced by Finite Element Analysis and the obtained morphological texture has been used for extracting the mechanical properties of the layer as a function of the thermo-compression process itself. A simulation method, based on the evaluation of the inelastic strain accounted per cycle has been used for matching the experimental results according to an aging model.

Design and Process Optimization of a Sintered Joint for Power Electronics Automotive Applications

Sitta, Alessandro;Sequenzia, Gaetano
2020-01-01

Abstract

The massive development of Hybrid and Electrical Vehicles (HEV) is strongly impacting the semiconductor industry demanding for highly reliable Power Electronic components. Within the engine compartment installation space is of major concern, therefore small size and high integration level of the modules are needed. Conventionally devices are typically soldered to ceramics substrates that are vacuum soldered to water-cooled base plates. The known reliability limitations of traditional solder joints are significantly limiting the power density increase, limiting the maximum operative temperature and representing a strong constrain for using high performances devices such as wide bandgap compound like Silicon Carbide (SiC). Silver sintering today has started to replace the solder joint from chips to carrier substrates, leaving one major reliability bottleneck. Combining properly temperature, time and pressure, a strong, highly electrically and thermally conductive bond is formed. The aim of this work is to develop an integrated methodology, numerical and experimental, to assess the Ag sintering die attach process for a SiC power MOSFET. Different process parameters have been benchmarked by means of physical analyses, performed at time zero and also after liquid-to-liquid thermal shock aging test. The sintering flakes densification process has been reproduced by Finite Element Analysis and the obtained morphological texture has been used for extracting the mechanical properties of the layer as a function of the thermo-compression process itself. A simulation method, based on the evaluation of the inelastic strain accounted per cycle has been used for matching the experimental results according to an aging model.
2020
978-3-030-31153-7
978-3-030-31154-4
Die attach, Thermal shocks, Finite Element Model, Silicon Carbide, Reliability
File in questo prodotto:
File Dimensione Formato  
Calabretta et al_2020_Sintered_Joint.pdf

solo gestori archivio

Descrizione: Paper
Tipologia: Versione Editoriale (PDF)
Dimensione 1.61 MB
Formato Adobe PDF
1.61 MB Adobe PDF   Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/381657
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 12
social impact