Does anyone know of any data on the high frequency magnetic properties of
kovar (or the variety of identical low expansion metals that go by other
trade names). Kovar is ferromagnetic at DC with a large initial
permeability in the 6000 - 13000 range depending on how it is heat treated
and annealed. Since it is commonly used as a leadframe material in
packages, it is important to know how the initial permeability changes as a
function of frequency. I am interested in the range from about 10 kHz to
100 MHz. Any literature references or manufacturer's catalog data would be
appreciated.
Thanks
Eric
Alterra Technology Co.