Silicone Silicone conformal coatings offer high humidity, corrosion, and thermal resistance, which make them the preferred choice for high temperature applications.
Thermal Silicones claim to fame is for high temperature applications. The soldering iron technique is also a high temperature application. Use caution and watch the fumes. Consult with the manufacturer before using this technique.
Mechanical Because silicones are normally more elastic than other types of coatings, this technique can be used with some success. Just remember, cutting and scraping can damage the board.
Chemical Over the past several years, chemical companies have developed solvents that are somewhat effective in removing silicone conformal coatings. Of these, the fastest and most popular is a methylene chloride based system. Several hydrocarbon-based solvents are alternatives to the methylene chloride based solvent. If dissolving just a small spot is a concern, you can use the slower but far more selective hydrocarbon-based solvents. These slower solvents will not attack epoxy-glass PC boards, their components, metals or other plastics. While not as fast as the methylene chloride, the hydrocarbon based solvents are more selective, and when not contaminated by water, will not attack epoxy-glass PCBs, their components, metals and most plastics. As in the case of the polyurethane’s, the coated board is immersed in the solvent at room temperature and allowed to stand until the silicone has dissolved or can be easily brushed off. The time required will vary with the solvent used, the type of silicone coating, the coating thickness, and the amount of surface area exposed. Typically, most coatings of 0.010 inch or less will be removed in 15 minutes to one hour. Certain chemically-resistant silicones may require extended immersion for several hours. The use of ultrasonics or agitation will reduce dissolving time.