Aerosol jet printing of nickel oxide nanoparticle ink with ultraviolet radiation curing for thin-film temperature sensors

Yi-Tse Chang,Hong-Tsu Young,Kuan-Yi Hung,Roland K Chen,Kuan-Ming Li

doi:10.1007/s00170-021-08046-7

Abstract

In this study, the ultraviolet (UV) radiation curing process and furnace curing process for curing aerosol jet printed nickel oxide (NiO) nanoparticle thin films were investigated. NiO has a negative temperature coefficient and can be used to fabricate temperature sensors. Four UV power settings (for 10 min) and four furnace temperatures (for 1 h) were used to cure the aerosol jet printed sensors. The resultant sensor resistance at 100 °C and 180 °C was measured, and the sensor’s sensitivity was characterized by a B value. Confocal microscopy was performed to characterize the sensor surface. The 60% UV power setting yields the lowest resistance and the highest B value among all sensors. The analysis of variations shows that the UV power setting is not a significant factor in the resistance and B value, while the furnace temperature is a significant factor. This indicates that UV curing is a more robust method and does not need to be optimized to achieve good results. The UV curing process not only reduces the required curing time but also improves the performance of the temperature sensor.

Highlights

Temperature sensors are used in many research and industrial applications, such as integrated circuit chips [1], micro-resistance temperature detector arrays [2], and measuring metal cutting temperature [3]
The goal of this study is to develop an optimized UV curing process for fabrication of thermistors using Aerosol jet printing (AJP)
This indicates that UV curing is a more robust curing process than furnace curing, as the B value, a performance measure of temperature sensors, is less sensitive to the UV power setting

Summary

Introduction

Temperature sensors are used in many research and industrial applications, such as integrated circuit chips [1], micro-resistance temperature detector arrays [2], and measuring metal cutting temperature [3]. NTC thermistors are mostly composed of transition metal oxides made of nickel (Ni) and combined with manganese, cobalt, and copper [4]–[7] Alternate materials, such as samarium (Sm) and terbium (Tb), for NTC thermistors are used in order to expand the measurable temperature range have been reported up to 1000°C in comparison to the typical maxima temperature up to 500°C [8][9]. Commercial NTC thermistors usually have a B value above 3500K [12].The required facilities to fabricate temperature sensors using conventional processes are expensive and time consuming. These processes consist of at least four steps including raw precursor molding, pre-sintering precursor, sintering precursor at 1000°C for several hours, and thermistor packaging [10].

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Conclusion