IRC Intro’s Anotherm Isolated Aluminum Substrates
TT Electronics IRC Advanced Film Division (Corpus Christi, TX) has developed a new substrate technology that can offer significant benefits over conventional polymer-based insulated metal substrates (IMS). Designated Anotherm™, IRC’s new material consists of a thermally-conductive aluminum alloy substrate insulated by a thin, chemically grown, anodized dielectric layer, with solderable screen printed conductors applied to the anodized layer.
“The Anotherm process utilizes low cost manufacturing methods which result in a product that is compatible with traditional surface mount technology assembly methods,” said Tom Morris, applications engineering manager for IRC’s Advanced Film Division. “Because of the high thermal conductivity that the base aluminum substrate offers, in many cases the Anotherm board eliminates the need for additional heatsinks.”
Traditional insulated metal substrate technology (IMS) often relies on a polymer or epoxy material that is mechanically applied to a bare aluminum substrate, which requires extensive surface preparation, as well as a minimum thickness of approximately 75 microns. In addition, traditional IMS technology is subject to delamination at high temperatures.
By contrast, IRC's Anotherm process chemically converts the surface of the base aluminum itself to a rugged anodized insulating layer with a uniform thickness of only 35 microns, giving the Anotherm substrate its superior thermal properties, as well as eliminating the potential for delamination or peeling.
IRC’s Anotherm substrates utilize an additive process that has fewer process steps than the subtractive process typically used for IMS board manufacturing, Morris continued. As a result, the Anotherm substrates allow much more flexibility and thermal efficiency, as well as cost savings in many applications. Typical applications for the Anotherm substrate include high brightness LED assemblies, LED packages, and power resistors for automotive applications.
Maximum operating voltage for the Anotherm substrates is 250VAC, with thermal impedance at 0.2°C per watt. Maximum continuous operating temperature is 400°C without a solder maskant and 175°C with a solder maskant.
