This paper presents an accurate thermal characterization of thin-film heaters manufactured on glass substrates. The characterization has been performed on Cr/Al/Cr meandered heaters. Techniques commonly adopted for measuring the temperature coefficient of resistance, the thermal resistance and thermal capacitance in the case of Si-based microheaters have been conveniently modified to consider the fundamentally different thermal parameters of a heater manufactured on glass. To reduce power consumption and thermal capacitance, a grating of 250-µm wide trenches, stopped at 80 µm from the opposite metalized front surface, was manufactured on the back side of the heaters, obtaining an increase of the thermal resistance of about 110% and a decrease of the thermal capacitance of about 65% when the glass is in good thermal contact with a heat sink. The measured values of thermal resistance and time constants on a heat sink and in air have been justified starting from realistic physical considerations. Finally, a novel thermal model suitable for microheaters on glass immersed in air was presented and validated by comparing its predictions with the experimental cooling behavior of the microheater and with the predictions of an exponential model.
This paper describes a novel and easily manufacturable method for increasing the thermal resistance of microheaters fabricated on glass substrates, thus decreasing the thermal dissipation of the devices. An automatic sawing machine was exploited to dig 240 μm wide trenches in order to thermally isolate the heater from the glass substrate and four different layouts of the trenches have been investigated. An improvement of the thermal resistance up to 217% on a heat sink and 30% in air has been obtained. The thermal capacitance was also considerably decreased, thus improving the dynamic thermal behavior
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.