Dielectric/Electrical Insulation 

A dielectric material is a substance that is a poor conductor of electricity but an efficient supporter of electrostatic fields. In practice, most dielectric materials are solid. Examples include porcelain (ceramic), mica, glass, plastics, and the oxides of various metals. Some liquids and gases can serve as good dielectric materials. A vacuum is an exceptionally efficient dielectric. An important property of a dielectric is its ability to support an electrostatic field while dissipating minimal energy in the form of heat. The lower the dielectric loss (the proportion of energy lost as heat), the more effective the dielectric material. Another consideration is the dielectric constant, the extent to which a substance concentrates the electrostatic lines of flux. Substances with a low dielectric constant include a perfect vacuum, dry air, and most pure, dry gases such as helium and nitrogen. Materials with moderate dielectric constants include ceramics, distilled water, paper, mica, polyethylene, and glass. Metal oxides, in general, have high dielectric constants. If the voltage across a dielectric material becomes too great -- that is, if the electrostatic field becomes too intense -- the material will suddenly begin to conduct current. This phenomenon is called dielectric breakdown. In components containing solid dielectrics, dielectric breakdown usually results in permanent damage.

MCI H-501****

Thermally conductive, conformal epoxy coating is a new concept in dielectric coating. It combines high electrical insulation (.003”= 1,000-2,000 volts/mil) with exceptionally good heat transfer. It has good physical properties, and a service temperature of (-65°C-+150°C [300°F]), resistance to water and a wide range of chemicals. It is particularly recommended for coating printed circuit boards, semiconductors, and heat sink assemblies. Circuit boards can be coated by spraying the entire circuitry, after masking the solder pads. The coating efficiently distributes the heat of the circuits throughout the surface of the board. This coating system requires post heat curing in a range from 150°F - 275°F, depending on service requirements, from 1 to 4 hours. 

PTFE Teflonâ*****
(Polytetrafluoroethylene) coatings have the lowest coefficient of friction and highest temperature resistance (260°C [500°] on a continuous basis) of any of the Teflon^® coating systems. PTFE coatings are very good electrical insulators and are extremely non-wetting. They are inert to almost all chemicals but are somewhat porous, and thus permeable to water vapor and other gases. The substrate must be able to withstand a cure temperature of at least (370°C [700°F]) to consider PTFE-based coating.  

Halar^® *****

Manufactured from ECTFE, is a melt processable fluoropolymer. Because of its chemical structure, a 1:1 alternating copolymer of ethylene and chlorotriflouroethylene, Halar offers a unique combination of properties especially as a coating and a liner. Halar fluoropolymer coatings provide outstanding chemical resistance, good electrical properties, a broad-use temperature range from cryogenic to (150°C [300°F]), and meet the requirements of UL-94 V-O vertical flame test in thicknesses as low as .007 (7mils). Halar is resistant to strong mineral and oxidizing acids, alkalis, metal etchants, liquid oxygen, and essentially all organic solvents except hot amines. The substrate must be able to withstand a cure temperature of at least (250°C [650°F]) to consider ECTFE-based coating. 
 

Lastly, we maintain a wide selection of Dielectric products in stock eliminating costly delays waiting for products to arrive, some as long as 2 weeks, in order for a project to begin. Each project is unique and specifications too numerous to list here, so please contact us to discuss your specific requirements.