Cambridge Nanotherm recently announced that its Nanotherm LC thermal management solution has solved the unique thermal challenges of chip-scale packaged (CSP) light-emitting diodes (LED) that are caused by the CSP being soldered directly onto a printed circuit board (PCB).
Cambridge Nanotherm has announced a solution to cool CSP LED. (Wikimedia Commons)
The patented Electro-Chemical Oxidation (ECO) process that Cambridge Nanotherm created converts the surface of an aluminum PCB into a “super-thin alumina dielectric layer” with a thermal conductivity of 7.2 W/mK. The layer is only microns thick, so the company claims that the thermal performance is as high as 115 W/mK.
According to the press release, “This means the heat from the CSP LEDs is conducted efficiently through the dielectric and into the aluminum board – ensuring the LED junction temperature is kept at a stable temperature.”
This is an important breakthrough, as CSP LED are expected to become a significant portion of the high-power LED market in the next few years. Without a standard sub-mount, CSP LED reduce the cost and size of the LED package and give designers room for creativity in making smaller, brighter, and more cost-effective lights.
The dielectric layer is the key, according to Cambridge Nanotherm, because metal-clad PCB are typically made of epoxy resin mixed with ceramic but there is a limit to how much ceramic can be introduced before the composite becomes brittle.
As Cambridge Nanotherm Sales and Marketing Director Mike Edwards explained, ““Epoxy-filled MCPCBs struggle to cope with the thermal profile of CSP designs, particularly when they are mounted close together on a module. Nanotherm’s unique Nanoceramic MCPCBs overcome these limitations, enabling designers to build increasingly power dense modules.”
Other companies are also making advances in CSP LED packaging and thermal management. Dow Corning recently announced that it was releasing three new highly reflective coatings that can work under extreme temperatures, as high as 150°C.