DocumentCode :
2642381
Title :
Electro-thermo-mechanical analyses on silver sintered IGBT-module reliability in power cycling
Author :
Dudek, R. ; Doring, R. ; Rzepka, S. ; Ehrhardt, C. ; Gunther, M. ; Haag, M.
Author_Institution :
Micro Mater. Center Chemnitz, Fraunhofer ENAS, Chemnitz, Germany
fYear :
2015
fDate :
19-22 April 2015
Firstpage :
1
Lastpage :
8
Abstract :
New demands on the thermo-mechanical design of sintered silver interconnections emerge. Development of this inter-connection technology and both experimental and theoretical studies on their reliability were subjects of the project “PROPOWER”. The focus of this paper is on theoretical analysis of thermo-mechanical reliability risks of a project demonstrator, an insulated-gate bipolar transistor (IGBT) module, subjected to power cycling loadings. Coupled electro-thermal-mechanical analyses have been carried out using the finite element method (FEM). Introduction of a new interconnect material means at the same time introduction of a new constitutive behavior and new failure modes. As the material stiffness increases, the decoupling effect of compliant solder layers reduces and intrinsic mechanical stresses increase in the whole power stack. This leads on one hand to less low cycle fatigue in the interconnect, as plastic dissipation is reduced, but on the other hand to higher failure risks like brittle cracking and sub-critical crack growth. However, if early brittle failure can be avoided by appropriate designs, the new interconnection technology allows an increase in fatigue reliability of several hundred percent. Based on the complex theoretical framework simulation results are validated by testing in order to achieve trustworthy thermo-mechanical reliability predictions. Failures like chip metallization damage and the different damage mechanisms of the die bond if either solder or sinter silver is used are related to the different stress situations in the module.
Keywords :
failure analysis; fatigue cracks; finite element analysis; insulated gate bipolar transistors; interconnections; microassembling; semiconductor device metallisation; semiconductor device models; semiconductor device reliability; silver; sintering; solders; thermal analysis; Ag; FEM; IGBT-module reliability; PROPOWER; brittle cracking; brittle failure; chip metallization damage; cycle fatigue; damage mechanisms; decoupling effect; die bond; electrothermomechanical analyses; failure modes; fatigue reliability; finite element method; insulated-gate bipolar transistor module; interconnect material; interconnection technology; intrinsic mechanical stresses; material stiffness; plastic dissipation; power cycling loadings; silver interconnections; sinter silver; solder layers reduces; subcritical crack growth; thermomechanical design; thermomechanical reliability predictions; thermomechanical reliability risks; Bonding; Insulated gate bipolar transistors; Resistance heating; Silver; Stress; Substrates;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE), 2015 16th International Conference on
Conference_Location :
Budapest
Print_ISBN :
978-1-4799-9949-1
Type :
conf
DOI :
10.1109/EuroSimE.2015.7103139
Filename :
7103139
Link To Document :
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