Cambridge Nanotherm of Haverhill, UK launched Nanotherm DMS, a unique direct-metallized single-sided thermal management solution for UV LED modules. The company notes that high-power UV LEDs pose a significant thermal challenge. Often only about 5 percent of the power going to a UV-C LED gets converted to photons. For the die to avoid overheating, the remainder of the energy must be conducted away as heat via the LED’s base to a thermally conductive PCB.
Shorter wavelengths of UV light degrade organic material. Therefore, the choice of PCB is often limited to inorganic materials. Hence, cost-effective metal-clad PCBs (MCPCBs) that rely on an organic epoxy based dielectric layer degrade too soon.
Ceramics Offer Choice Between Alumina and Aluminum Nitride
According to the company, engineers can choose ceramics, but they have to strike a compromise between low-performance but cost-effective alumina (25W/mK), or high-performance but expensive aluminum nitride (140-170W/mK).
Such ceramic materials are also brittle and prone to cracking. Cambridge Nanotherm says it has developed Nanotherm DMS to address these issues.
The company asserts that Nanotherm DMS combines the robustness and manufacturability of aluminum with the superior thermal performance of AIN and as it undergoes thin-film processing, and the new material is entirely inorganic.
Nanotherm’s direct metallized single-sided (DMS) PCB employs an extensively patented electrochemical oxidation (ECO) process to convert the surface of aluminum into an alumina dielectric layer. This nanoceramic alumina has a thermal conductivity of 7.2W/mK which is just tens of microns thick. Using a direct metallization process gives the material a composite thermal performance of 152W/mK.
Cambridge Nanotherm DMS Material Much More Robust
While this heat conductivity is slightly inferior to the very best and most expensive AIN substrates, the firm contends that the mechanical robustness of the Nanotherm metal board enables better mounting approaches that lead to overall measured system performance that exceeds the performance of aluminum nitride.
Cambridge Nanotherm sales and marketing director Mike Edwards commented, “The challenge for module manufacturers remains how to balance thermal requirements with cost and practicality. With Nanotherm DMS there is now an option that brings together the performance of ceramics with the robustness and manufacturability of MCPCBs and being fully inorganic it won’t degrade with use.”
“Nanotherm DMS is designed to meet the extremely challenging requirements of the UV industry and offers the only alternative to ceramics on the market,” Edwards said.
