Mingxiu Li

Improvement of reliability for high-ohmic Cr–Si thin film resistors in a heat and humid environment: Removing moisture source by electrocatalytic decomposition of water

Abstract The reliability of high-ohmic Cr–Si thin film resistors in a heat and humid (HH) environment is often guaranteed by packaging materials as protection layers. Our previous study shows that Cr–Si–Ni film has a better performance in HH resistance than Cr–Si film in the same experimental conditions, and the proposed hypothesis that the electrocatalytic activity of Ni in the resistive film leads to water decomposition is considered as the reason behind it. In addition, NiMo alloy film is reported to have a better electrocatalytic activity on water decomposition than Ni film. So an issue arises: will the Cr–Si film co-doped by both Ni and Mo have a better performance in HH resistance than Cr–Si film only doped by Ni? In our current full paper, Cr–Si–Ni–Mo and Cr–Si–Ni films with low temperature coefficient of resistance (TCR) were prepared and compared in the same conditions to study their performance in a HH environment, which may address the raised issue from experimental data and further verify the proposed hypothesis. Possible reasons for the experimental results were discussed. If the proposed hypothesis is true, another way may be opened up to improve the reliability of high-ohmic Cr–Si resistors in a HH environment.

Degradation behavior and mechanism of polymer films for high-ohmic resistor protection in a heat and humid environment

Abstract The protection of polymer films is critical to the reliability of high-ohmic resistors working in a heat and humid environment, and temperature is the main factor resulting in failure of coated resistors. However, in this study hydrogen evolution reaction (HER) and corrosion reaction of OH − ions are found to be another two important factors determining the fate of coated resistors. When temperature effects can be neglected, corrosion resulted from OH − ions generated in HER may be the major reason of polymer degradation, the mechanism of which is discussed based on the polymer films mainly formed by phenolic and epoxy resins.