Corrosion Protection with Parylene
A natural process, corrosion enacts chemical/electrochemical reactions that degrade and gradually destroy materials or components within a functional environment. The outcome can be dangerous and costly to repair.
For printed circuit boards (PCBs) and similar assemblies, corroded electrical contacts can cause potentially life-threatening mechanical malfunction of aerospace/automotive/industrial systems during operation; corroded medical implants may disrupt pacemaker function or lead to blood poisoning. PCBs can suffer electrolytic corrosion, when:
- electrical contacts within the assembly are subject to water or other moisture trapped between them.
- Applied electrical voltage causes development of unintended electrolytic cells, which can decompose chemical compounds, initiating corrosive reactions.
- However, contaminants such as chemical residue, dirt, oil and salt trapped between the substrate surface and the conformal film can also generate corrosion.
- Although corrosion generally starts from underneath a conformal coating, because of liquid/residue on the substrate surface, rapid changes in temperature can also crack or rupture the coating’s external layer, instigating corrosion response.
- Similarly, metal components within a PCB can produce oxides or salts within the operating environment, leading to corrosive dysfunction.
- Other assembly materials, like ceramics or plastics, can also suffer corrosion and subsequent degradation of their useful properties, performance expectations and structural integrity.
Considering the smaller size of PCBs, some corrosion mechanisms are less visible and therefore difficult to predict, but pits and cracks can develop, leading to wider spread physical disruption of assembly surfaces and interiors. Conformally coating PCBswith the non-critical, non-toxic layer material parylene (XY/poly-para-xylylene), can prevent corrosion in most cases.
Conformal Coating Parylene Coating Protective Coatings Rustproofing & Protective Services Design & Decorative Coatings Metal Powder Coating Services Powder Coating Equipment & Supplies Plastics Coating Services Electronic Equipment Manufacturers Electroni