2018 Volume 67 Issue 12 Pages 513-518
We studied a highly accelerated corrosion test method for in-vehicle electronic modules. In the module, a circuit board on which the silver wiring was formed was stored in a casing sealed with silicone. SO2, H2S, S8 gas tests were conducted under the condition of 3300 ppm/90℃/80%RH in SO2 test, 60 ppm/90℃/80%RH in H2S test, and 4 ppm/90℃/<10%RH in S8 test. As a result of examining the corrosion rate of the silver wiring, it was found that the S8 gas test has the highest rate of corrosion acceleration. High corrosion rate is presumed to be due to high permeability of S8 gas through silicone, in addition to its high corrosion ability to silver. Based on this result, we propose S8 gas test as a sulfur corrosion accelerated test method.