Keep in mind that not every PCB contains all the layers listed â the need for different layer types depends on the specifics of your design. Single layer boards typically include: a mechanical layer, a keep out layer, a routing layer, an overlay layer, a solder mask layer and a solder paste layer.
An austenitic (300 series) stainless steel will outlast both aluminum and steel exposed to rain or salt spray. Steel without a protective coating will do poorly in both environments but if properly plated or painted, may last a long time. The aluminum alloys likely to be found in many consumer products may develop âlawn chair diseaseâ exposed to at least urban rain and condensation but possibly also in cleaner environments as well (up to you to test).
Corrosion between anodized aluminum and steel. Aluminum is a reactive metal (un-noble), which should have a low corrosion resistance according to thermodynamics. The high corrosion resistance found on aluminum nevertheless, is due to the presence of a thin, compact film of adherent aluminum oxide on the surface.he galvanic series for metals shows that aluminum will be the anode of the galvanic cell in contact with almost all other metals and hence the one which suffer from galvanic corrosion. The galvanic corrosion performance of the different aluminum alloys is quite similar, so that changing alloys cannot solve the problem.