SIGEL 8605 Automotive-Grade High-Temperature Resistant Silicone Gel | Potting and High-Temperature Insulation Protection for Power Modules
Three Major Challenges Faced by High-Temperature Encapsulation Power modules are becoming increasingly compact while operating under heavier loads. For IGBT and SiC power devices as well as new energy vehicle electronic control modules, potting materials are challenged not only by one-off high-temperature shocks, but also by the combined effects of long-term thermal ageing, thermal cycling and electrical stress. Can the potting silicone gel remain soft after continuous ageing at 220°C for 2000 hours? According to ELAPLUS SIGEL 8605 datasheet, after thermal ageing in air at 220°C, the penetration of this material drops from 82 to 72 (1/10 mm), with a change rate of -12.2%, and the weight loss is only 1.6%. These figures provide specific evaluation criteria for material selection for electronic encapsulation in high-temperature zones. Three Major Challenges Faced by High-Temperature Encapsulation 1. Why Should Power Module Potting Not Be Judged Only by Maximum Temperature Rating? Inside the encapsulation cavity of power devices, chips, bond wires, metal terminals and different substrates feature mismatched thermal expansion behaviours. As the module undergoes repeated heating and cooling cycles, the encapsulation material must not only provide electrical insulation and environmental isolation, but also buffer delicate interconnection structures with sufficiently low stress. Ordinary gels may gradually harden, discolour or crack under prolonged high temperatures, losing their original soft buffering capability. Volatiles and material weight loss also deserve attention. Therefore, when evaluating high-temperature silicone gels, penetration, weight loss and electrical performance after ageing should be incorporated into one set of validation logic, instead of making judgements merely based on short-term temperature resistance indicators. 2. Performance of SIGEL 8605 after 2000 Hours of Ageing at 220°C SIGEL 8605 is a transparent two-component addition-curable self-healing silicone gel with a 1:1 mixing ratio by weight. After curing, it forms a soft, transparent gel layer that coats internal chips…
