Extremely Stable 10 kΩ Metal Foil Resistors in n Ω/Ω Level

Ultrastable metal foil 10 k $\Omega $ standard resistors are developed. The resistors showed quite stable behavior and the observed long-term resistance drift was around ±10 n $\Omega $ / $\Omega $ in 2 years from just after the fabrication. They showed almost linear temperature characteristics from $18~{}^{\circ } $ C to $28~{}^{\circ } $ C, and the temperature coefficients were less than 15 (n $\Omega $ / $\Omega $ )/K at around $23~{}^{\circ } $ C. Due to their stress-free structure, the resistance values were quite stable within 5 n $\Omega $ / $\Omega $ after the abrupt temperature change of about $5~{}^{\circ } $ C. The humidity dependence was within ±0.2 (n $\Omega $ / $\Omega $ )/% at $23~{}^{\circ } $ C, and they also showed stable behavior within ±10 n $\Omega $ / $\Omega $ against the pressure from 700 to 1200 hPa. A vibration test along with an MIL standard, MIL-STD-202, was performed, and a 2.5 k $\Omega $ subsection of the 10 k $\Omega $ resistor indicated stability within 10 n $\Omega $ / $\Omega $ after applying vibration for 2 h on each axis (6 h in total).