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Thermal and Mechanical Fatigue Including Vibration: Task Group 2

Task Group 2 is focused on thermal and mechanical fatigue.

Failures of cell interconnects and solder bonds have been identified as a key cause of long-term failure of PV modules. The primary stresses affecting the failure rates have been shown to be thermal and mechanical. This task group studies how to induce and quantify these failures.

Progress Update

There is a consensus that 200 thermal cycles do not adequately stress a module, so discussion has focused on how to increase the amount of stress without extending the test for a prolonged time. Finite Element Modeling (FEM) has been used to quantify the number of thermal cycles in the chamber needed to simulate a lifetime in the field.

Standards Activities

Based on the above mentioned FEM studies, a New Work Item Proposal IEC 62892-2 "Testing of PV modules to Differentiate Performance in Multiple Climates and Applications — Part 2 Test Procedure for Thermal Cycling" was reviewed by IEC and is now being revised based on the initial comments. This draft provides options for reducing the time for the thermal cycling test by increasing the maximum temperature reached by the module during the thermal cycles.

Related Resources

IEC 62892-1 "Testing of PV modules to differentiate performance in multiple climates and applications – Part 1: Requirements for testing" is being developed by IEC Technical Committee 82; the first Committee Draft has been reviewed by the National Committees.

Climate Specific Thermomechanical Fatigue of Flat Plate Photovoltaic Module Solder Joints, Microelectronics Reliability, March 2016

Task Leaders

Nick Bosco — NREL, representing the Americas
Tadanori Tanahashi — AIST, representing Japan
Simon Xiao — Trina Solar, representing China.

Other leaders are welcome.