Electroless Nickel Resistors Formed on IMST Substrate

Ni-P alloy resistors electrolessly plated on a unique insulated metal substrate technology (IMST) substrate are described. The construction of the IMST substrate with electroless nickel resistors is presented. The resistor fabrication processes are shown. The obtained practical sheet resistivity of electroless nickel resistors was 0.5-20
Omega
/
box
. Laser trimming was utilized to produce resistors with a tolerance of ±0.1 percent; and a resistance range from 0.1
Omega
to 100 k
Omega
. The thermal coefficient of resistance (TCR) was closely related to the phosphorus content. A TCR of +80 ppm/°C minimum was obtained. The eleetroless nickel resistors exhibited excellent stability in various life and high power dissipation tests. Applications to audio power hybrid integrated circuits(IC's) and resistor arrays are shown.