Proposal of an Accelerated Test Method in Sulfur Corrosion of the Housing Structure Electronic Components Mounted in Engine Rooms

Abstract

The purpose of this investigation is to find a highly accelerated corrosion evaluation method which shorten the evaluate time of the corrosion resistance of electronic components having housing structures in which silver conductor formed circuit substrates are contained and are sealed with silicone. We applied three test conditions using three gaseous species such as SO₂, H₂S, and S₈, respectively. We adopted in SO₂ test(3300ppm/40℃/100%RH), H₂S test(60ppm/40℃/100%RH) and S₈ test(4ppm/90℃/<10%RH), respectively. As a results of the observations and analyses of the tested samples, it was found that the test using S₈ showed the highest corrosion rate among those using three kind of gases. This high corrosion rate of S₈ was estimated in conjunction with the higher permeability of S₈ through silicone and corrosivity of S₈ itself.