THERMAL CONDUCTIVITY MEASUREMENT OF SOLIDS BY FREESTANDING SENSOR-BASED 3ω TECHNIQUE
The freestanding sensor-based 3-omega technique was realized for the replacement of widely used conventional 3-omega technique. A freestanding sensor made of nickel sensor sandwiched by Kapton protective films was fabricated by flexible MEMS fabrication process. Compared with the conventional 3-omega sensor which is deposited on the measured surface, both the useful life and insulation of the sensor are greatly improved. The new sensor works well for solids with high thermal conductivity. However, for specimens whose thermal conductivity was lower than that of the protective film, the classical temperature curve was distorted and the curve section representing the protective film vanished. Thus, two-dimensional heat conduction in the protective film has to be considered and the classical method for estimating the specimen thermal conductivity is also changed. This article extended the freestanding sensor-based 3-omega technique to characterize solids with lower thermal conductivities, and proved considering the anisotropy of the protective film when fitting the specimen thermal conductivity was proper. Experimental results showed the new technique was suitable for low thermal conductivities characterization, nearly down to 0.2W/m K. We also presented an analysis of the freestanding sensor-based 3-omega technique for different experimental conditions. Effects considered included the heated line-width of the sensor and the protective film thickness. Several experimental results showed the heated line-width of the sensor greatly influenced the fitted accuracy of the specimen’s thermal conductivity but the protective film thickness had little effects on the fitted value of the specimen’s thermal conductivity.
Lin Qiu Dawei Tang Xinghua Zheng Guoping Su
Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing, China, 100190 Institute of Engineering Thermophysics Chinese Academy of Sciences
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
1109-1115
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）