Printed Circuit Board (PCB) and Flexible Printed Circuit (FPC) Conformal Coating
Conformal coatings are often applied to PCB/FPC assemblies for the purpose of providing electrical insulation, supplying protection against environmental elements, and enhancing resistance to mechanical vibration. These coatings “conform” to the various component geometries on the populated circuit board. While they are intended to be impermeable barriers, conformal coatings must be breathable to allow trapped moisture on the PCB surface to migrate away from active conductive paths. To minimize the risk of trapped moisture, it is recommended that manufacturers properly clean and dry their boards prior to coating. Coating adhesion can also be significantly improved when they are applied to clean, dry boards and films.
Tangent Industries’ solvent-free conformal coating products consist of light curable acrylated urethanes and cationic epoxies. The acrylated urethanes include products that possess high flexibility after cure. This makes them ideal candidates for flex circuits and PCB’s with delicate components and thin gage wire leads. Curing in seconds under moderate intensity UV/Visible light, these coatings yield dry, tack-free surfaces. They are highly moisture resistant, and their low Shore A-scale hardness makes them easier to remove for localized repair.
As their exclusive distributor for the Americas, Tangent offers Vitralit® brand light curable cationic epoxies from Panacol-Elosol. Panacol-Elosol GmbH is part of the Hönle Group headquartered in Germany, and has been formulating and manufacturing adhesives for over 30 years. Cationic epoxy coatings are typically more durable by nature, offering higher resistance to extremely harsh operating environments and chemicals. They cure with UV light, and produce dry, tack-free surfaces. In the event that UV exposure is prematurely terminated, the initiated cationic curing process will continue to completion in the areas previously illuminated. This provides an added degree of assurance that full cure is consistently attained in the established bonding process.
View the conformal coating selections listed below for a possible candidate for your application. Please contact Tangent to confirm your product selection and to secure additional application assistance, including samples and process recommendations. In the event that these standard products do not satisfactorily address your performance requirements, Tangent will investigate other solutions that include development of adhesive specifically tailored to the complexity of your application.
|Product Number||Suitable Applications||Viscosity cP mPa||Shore Durometer||24 Hour Water Absorbtion||LEDcure||Bondable Substrates||Comments/Features||Request
|conformal coating||200-400||D75-85||< 1.0%||yes||FR4 epoxy board, glass, metal,ceramic,plastics||multicure: UV/Visible light / thermal / activator|
|conformal coating||70-150||D75-85||< 1.0%||yes||FR4 epoxy board, glass, metal,ceramic,plastics||multicure: UV/Visible light / thermal / activator|
|conformal coating||100-200||D 80-85||< 1.0%||No||FR4 epoxy board, glass, metal,ceramic,plastics||UV cure, developed for use as a conformal coating in PCB assembly, very bright fluorescing additive to permit inspection of coverage using automated vision systems|
|conformal coating||60-100||D15-25||< 1.0%||no||FR4 epoxy board, glass, metal,ceramic,plastics||UV cure, secondary thermal cure, soft/flexible cationic epoxy, clear, chemical resistant, fluorescing, ideal for spray dispense|
|conformal coating||200-300||D40-50||< 0.5%||no||FR4 epoxy board, glass, metal,ceramic,plastics||UV cure, secondary thermal cure, flexible cationic epoxy, clear, chemical resistant, fluorescing|
|conformal coating||200-300||D40-50||< 0.5%||no||FR4 epoxy board, glass, metal,ceramic,plastics||UV cure, secondary thermal cure, flexible cationic epoxy, clear, chemical resistant, low flow characteristics for better containment after dispensing|
|conformal coating||100-200||D40-50||< 0.5%||no||FR4 epoxy board, glass, metal,ceramic,plastics||UV cure, secondary thermal cure, flexible cationic epoxy, clear, chemical resistant, fluorescing|
*Note: viscosity variations are typically available, or can be formulated, for all listed products. Please inquire with Tangent Applications Engineering for viscosity ranges not shown in the table.
Contact Tangent Industries for more info.