Dow Corning’s silicone-based, next-generation Electrically Conductive Adhesive (ECA) ‘PV-5802’ will be used in Tianwei New Energy’s Metal Wrap Through (MWT) module production line, developed by ECN of the Netherlands. PV-5802 is said to provide improved electrical properties and stability, which will greatly enhance the electrical performance, reliability and durability of MWT modules.
Conductive adhesives are used to attach and make electrical contact between the current carrying ribbons, busbars and back contact sheets of the cells. Degradation in the interconnect may affect current carrying capacity. Conductive adhesives capable of withstanding stresses in a PV module with minimal degradation over a 20-plus year product life cycle are required.
Dow Corning’s PV-5802 new silicone-based ECA has been developed for the Metal Wrap-Through module technology. It was said to have demonstrated excellent conductivity and production yield in tests on Tianwei’s MWT production line. The MWT modules using PV-5802 had very low cell-to-module power loss, less than 0.4%. The full area module efficiencies reached 16.8 %, for multi-crystalline silicon modules. In accelerated ageing tests, the modules showed very low degradation: 0% loss after 300 thermal cycles (between –40 °C and 85 °C), and 0.2% loss after 1500 hours in damp heat conditions (85 °C, 85 % relative humidity).
Dow Corning’s conductive adhesives can also be used with other PV back contact module manufacturing applications, such as IBC as well as MWT solar cells.
The PV-5802 ECA has an Ag filler content below 60% but maintains a conductivity after curing below 1 mOhmcm. It is flexible over a wide range of temperatures, which enables stress-relief and is beneficial for durability. Also designed to be compatible with Organic Solderability Preservative (OSP)-finished contact backsheet (CBS).