The Impact of a Faster Thermal Cycling Profile on PV Cell Interconnect Cycles to Failure

• Published in: Conference record of the IEEE Photovoltaic Specialists Conference Vol. 2018
• Main Authors: Lippiatt, John, Westerberg, Staffan, Rose, Doug
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.06.2018
• Subjects: interconnects; photovoltaic cells; rapid thermal cycling; reliability; SOLAR ENERGY; thermal cycling; thermal shock
• ISSN: 0160-8371

The thermal cycling tests used in the photovoltaic industry are slow, requiring over a month for 200 cycles and five months for 800 cycles. A faster alternative would reduce the cost of delay for module qualification. This study investigates the correlation between a baseline thermal cycling profile and profiles that are three and six times faster. Interconnect failure data for each profile was gathered across eight splits of varying material combinations. Models were applied to the failure data and factors which impacted interconnect lifetime were identified. Here, the results show that more cycles were required in the faster profiles for equivalency to the baseline profile. Furthermore, the equivalent number of cycles varied by a factor of two across the splits. Despite these limitations, the faster profiles offer substantial qualification time savings if the underlying failure mechanisms are understood.