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).
Anodized aluminum can replace stainless steel in certain applications. The ways that anodized parts can be used instead of stainless steel are only limited by designers and engineers imaginations. Some of the benefits of using anodized aluminum components in place of stainless steel include: 1  Less weight. 2  Less expensive to produce, handle and ship. 3  Can be machined twice as fast as stainless steel.  Machine components with tight tolerances can be anodized without changing the dimensional requirements of the part.