New Industry Products

IRC Offers Thick Film Copper Substrates with Low Resistivity

August 30, 2007 by Jeff Shepard

TT electronics and its IRC Advanced Film Division has announced that its solderable thick film copper substrate is now being specified for high-current and power module applications. Designated the TFC Series, the patented copper formulation utilizes a screen-printing process where the copper traces are printed on an alumina ceramic substrate and fired at temperatures up to 1000°C.

According to Tom Morris, Applications Engineering Manager for IRC Advanced Film Division, the thick film copper substrates provide a number of advantages over direct bonded copper (DBC) substrates. "Because the thick film copper substrates utilize an additive process as opposed to the etching process required by DBC substrates, the copper substrates are cost effective, and high-current, current sense resistors can be integrated into the conductors on the substrate. Additionally, the thick film copper formulation provides the substrates with high current carrying capability and excellent thermal management characteristics."

The TFC Series copper substrates are suitable for a variety of power applications where a significant amount of current is required, such as thermo-electric coolers and power modules.

The TFC Series substrates feature an adhesive copper strength of >20N/mm², thermal expansion of 7.3ppm/°C, very low thermal impedance, and sheet resistivity of 0.2mΩ/@ (180µ thick). Conductor thickness ranges from 20 to 250µ, with a minimum conductor width and space between conductors of 0.5mm.

When integrated onto the substrate, the resistors feature an ohmic range down to 0.001Ω, with tolerances to ±1%, suitable for current sensing or high power dissipation.

The substrates are available in thicknesses ranging from 0.25 to 1.0mm, and sizes up to 4.5 in. x 6.25 in. They can be laser-scribed or green-scored.