Zentrix offers flanges plated with Ni:Co + Au for use in RF packages. The flange material can be pure Cu, Mo or W, or the composites CuW, CuMo, Cu-CuMo-Cu lamination (CPC), or Cu-Mo-Cu lamination (CMC). Like all of Zentrix's Ni: Co + Au electroplated finishes, these flanges are compatible with AuSi eutectic die attach. Plated flanges are used for wide variety of applications, including:
Substrates for gold-plated BeO pill packages. The BeO can be soldered to the plated flange with AuSn solder (also available from Williams).
Substrates for discrete ringframes that are epoxied onto the flange. The ringframes can be made of liquid crystal polymer (LCP), alumina, or some other dielectric.
Substrates for circuit boards with cut-outs. The circuit can be formed on FR-4 , TeflonTM or some other PC board material. The chip is soldered directly onto the flange and is surrounded by the circuit board.
Zentrix's proprietary plating process produces flange surfaces that are free of pits, scratches or other defects that would prevent a good die attach. Scratch-free surfaces are especially important for flanges with outer surfaces made of copper, which is a soft metal.