Global Circuit Assembly & Semiconductor supplier, MacDermid Alpha Electronics Solutions has teamed up with its electro-chemicals brand, Electrolube and a tier 1 automotive supplier to provide the best solution for protecting supplier’s on-board charger.
The automotive customer found an ideal production partner in Electrolube, whose UR5608 tough polyurethane potting and encapsulation compound proved the best solution for protecting their on-board charger.
Bethan Massey, Global Product Manager for Encapsulation Resins at Electrolube, part of MacDermid Alpha Electronics Solutions, comments, “Our automotive customer was very pleased with the solution that we offered them, and we are confident that our problem-solving capabilities and commitment to providing innovative and reliable solutions, will ultimately secure our position as the leading provider of electro-chemical products to the automotive industry.”
The automotive supplier was originally looking for a thermal management material to fill air gaps, and dissipate heat, between the PCB and cooling channels in their on-board charger. They believed that they needed a material with thermal conductivity in the region of 4-6 W/m.K.
After further discussion to understand the application in more detail, Electrolube determined that the automotive customer had hot spots on their PCB when a thermal management material was used.
This was caused by the high viscosity of these products and the very small gaps in the on-board charger that the material needed to flow into, which left air pockets remaining after filling. Air is a poor conductor of heat, approx. 0.025 W/m.K, and therefore the remaining air pockets reduced the efficiency of heat transfer.
Electrolube proposed looking at a thermally conductive resin with lower viscosity and better flow properties, to be able to fill even the smallest gaps in the unit more effectively.
Furthermore, the customer also needed high dielectric strength, excellent protection to automotive fluids and support against vibration, whilst also offering flexibility for fragile components during thermal shock.
These specific requirements led Electrolube to suggest the versatile UR5608 polyurethane resin that provides excellent flow even in small (~0.5mm) spacings, with a good mixture of support and flexibility.
Electrolube resin, UR5608 delivers a dielectric strength of 18 kV/mm and is UL94 V-0 approved. Despite the resin having a lower thermal conductivity of 0.78 W/m.K than the original specification, the low viscosity UR5608 proved to be highly successful at eliminating any air gaps in the system, which dramatically reduced the thermal resistance.
The automotive customer tested Electrolube resin, UR5608 and Electrolube also worked with them to achieve the most efficient production processes by recommending gently heating the material and potting the unit at a slight angle to further improve flow and flush out all air pockets from the unit.
When tested, UR5608 flowed well through the customer’s unit, and they achieved the heat dissipation that was required.
UR5608 was subsequently approved for the application after demonstrating effective heat transfer between certain hot components, inductors and capacitors, and the liquid cooling channels within their aluminum metal casing.