Material Considerations
Selection of the correct choice of coating material (lacquer) is one of the process engineer's most critical decisions. Criteria for selection must be based on answering many questions, which will include:
- What is being protected against? (e.g., moisture, chemicals)
- What temperature range will the electrical device encounter?
- What are the physical, electrical, and chemical requirements for the coating material itself?
- Electrical, chemical, and mechanical compatibility with the parts and substances to be coated (for instance, does it need to match the coefficient of expansion of chip components?)
Answers will determine the suitability of a particular material, be it acrylic, polyurethane, silicone, epoxy, etc. Process, production and commercial issues will then enter the equation:
- How easily can the material be reworked once applied?
- How fast does the material dry (cure)?
- How fast can the material be applied and dried (throughput time)?
- What type of process and equipment is necessary to achieve the required coating quality (uniformity and repeatability)?
- Price of the material per litre.
- Quality of the material supplier (two acrylic material manufacturers will not make equal quality of material).
Read more about this topic: Conformal Coating
Famous quotes containing the word material:
“The only happy talkers are dandies who extract pleasure from the very perishability of their material and who would not be able to tolerate the isolation of all other forms of composition; for most good talkers, when they have run down, are miserable; they know that they have betrayed themselves, that they have taken material which should have a life of its own, to dispense it in noises upon the air.”
—Cyril Connolly (1903–1974)