Customers today increasingly demand for high levels of performance from electronic equipment. It becomes increasingly challenging for manufacturers to ensure the electronics operate for a prolonged period of time. Delicate components, densely populated printed circuit boards, confining packaging and highly demanding service environments usually result into increased failure rates because of excessive heat buildup and electrical interferences. Electronic equipment is often subjected to one or more stresses that impair performance. During manufacturing and assembly components are exposed to heat, cleaning agents and other chemicals that interfere with circuit operation. Through the use of electrical potting compound, the highest level of protection is provided from environmental, thermal, chemical, mechanical and electrical conditions.
Making a choice for electrical potting compound
Epoxies and silicones are the most commonly used electrical potting compounds. Epoxy resins are very stable materials before and after hardening with temperature resistance of up to 400oF (200oC). Aside from excellent strength provided, epoxies have excellent adhesion to metals and porous surfaces. These properties of epoxies can be applied to PCBs, capacitors, power electronics, LED lighting and sensors. A critical part in the selection of the proper electrical potting compound is developing a balance between the final properties with handling and processing issues such as open time, viscosity, cure schedule and other factors.
Epoxies as the best choice for electrical potting compound
Epoxies are clearly the best choice when chemical resistance, good physical strength and first-rate electrical insulation is required because epoxies can withstand repeated temperature excursions above the glass transition temperatures, a particular grade which should not be ruled out for applications involving shorter dwell times at higher temperature. Epoxies are typically used with fillers to lower shrinkage, enhance dimensional stability and thermal conductivity while retaining electrical resistance. The unparalleled versatility of epoxies is exemplified with their wide service temperature range. Some grades that are developed are able to withstand cryogenic conditions while others are resistant to extremely high temperatures. Since electronics are becoming highly popular, the use of pre-mixed and frozen epoxies is normally used for small potting applications.
Silicone as an electrical potting compound
Silicones also offer unparalleled combination of high temperature resistance as an electrical potting compound with superb electrical properties and flexibility. Silicones are softer than epoxies and they exert less stress on sensitive electronics and make it possible to retrieve components that require removal or repair. The properties of silicone can be adjusted through the use of fillers such as those that achieve thermal conductivity and flame retardancy.
UV curable potting compounds
This electrical potting compound has a unique chemistry that allows for ultra-fast curing usually under a minute. These materials cure through exposure to a UV light source where the thinner the layer the faster will be the curing rate. If the area that requires potting contains shadowed out portions, a secondary curing mechanism that utilizes heat is required. Both UV and its dual core counterparts can cure rigid and flexible but fillers cannot be added to these systems and their usage is limited by depth of cure. This electrical potting compound is used selectively for special encapsulating applications.
Making a choice for electrical potting compound
Epoxies and silicones are the most commonly used electrical potting compounds. Epoxy resins are very stable materials before and after hardening with temperature resistance of up to 400oF (200oC). Aside from excellent strength provided, epoxies have excellent adhesion to metals and porous surfaces. These properties of epoxies can be applied to PCBs, capacitors, power electronics, LED lighting and sensors. A critical part in the selection of the proper electrical potting compound is developing a balance between the final properties with handling and processing issues such as open time, viscosity, cure schedule and other factors.
Epoxies as the best choice for electrical potting compound
Epoxies are clearly the best choice when chemical resistance, good physical strength and first-rate electrical insulation is required because epoxies can withstand repeated temperature excursions above the glass transition temperatures, a particular grade which should not be ruled out for applications involving shorter dwell times at higher temperature. Epoxies are typically used with fillers to lower shrinkage, enhance dimensional stability and thermal conductivity while retaining electrical resistance. The unparalleled versatility of epoxies is exemplified with their wide service temperature range. Some grades that are developed are able to withstand cryogenic conditions while others are resistant to extremely high temperatures. Since electronics are becoming highly popular, the use of pre-mixed and frozen epoxies is normally used for small potting applications.
Silicone as an electrical potting compound
Silicones also offer unparalleled combination of high temperature resistance as an electrical potting compound with superb electrical properties and flexibility. Silicones are softer than epoxies and they exert less stress on sensitive electronics and make it possible to retrieve components that require removal or repair. The properties of silicone can be adjusted through the use of fillers such as those that achieve thermal conductivity and flame retardancy.
UV curable potting compounds
This electrical potting compound has a unique chemistry that allows for ultra-fast curing usually under a minute. These materials cure through exposure to a UV light source where the thinner the layer the faster will be the curing rate. If the area that requires potting contains shadowed out portions, a secondary curing mechanism that utilizes heat is required. Both UV and its dual core counterparts can cure rigid and flexible but fillers cannot be added to these systems and their usage is limited by depth of cure. This electrical potting compound is used selectively for special encapsulating applications.
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