| Corrosion and Galvanic Compatibility Knowledge
Corrosion Testing Equipment
The design techniques discussed in this section are a summary of recommended “Don'ts” based on features that have displayed significant impact on the durability and reliability of your product and equipment in service.
“Don’ts”
- Don’t use dissimilar metal (galvanic) couples if it can be avoided.
- Don’t use RTV that contains acetic acid.
- Don’t use heat shrink (non-sealed) electrical connector boots to stop moisture fluid intrusion.
- Don’t mate magnesium to a metal more cathodic than aluminum.
- Don’t use acrylic, RTV or varnish type conformal coatings.
- Don’t use gold over silver or copper.
- Don’t use organic materials that outgas, support fungi, absorb moisture or are degraded by maintenance and operational fluids.
- Don’t use an EMI gasket without a seal on both sides of the conductive element.
- Don’t use top mounted lid fasteners.
- Don’t mount PWBs horizontally.
- Don’t mount electrical connectors (multicontact or coaxial) vertically.
- Don’t place edge connectors on the bottom edge of a vertically PWB.
- Don’t create side loads or cable tension on the rear seal of electrical connectors.
- Don’t use direct air cooling on active electronic components.
- Don’t mount equipment less than 1/2 inch above the compartment floor.
- Don’t use hygroscopic materials.
- Don’t use nickel plated electrical connector shells in salt or high humidity environments. (Use cadmium plated shell).
- Don’t use foam cushioning material that can deteriorate (revert).
- Don’t permit the presence of water trap areas.
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