A device and method for measuring thermal conductivity of thin films based on mems technology

Abstract

The invention discloses an MEMS technology based film strain thermal conductivity test device and method. The device includes a heating stand arranged under an external shielding cover; an objective table is arranged in the external shielding cover; a piezoelectric testing device is arranged on the objective table; a testing sheet is placed on the piezoelectric testing device; a temperature sensorand a vent hole are arranged on the inner wall of the external shielding cover; displacement can be applied to drive a connecting sheet through a piezoelectric driving member of the piezoelectric testing device; the displacement can be applied to the connecting sheet to make a film on the testing sheet plated with the film generate strain; and the magnitude of the strain is the ratio of the applied displacement to the design size of a strain gauge. The thermal conductivity of a to-be-tested film can be obtained by controlling the magnitude of film strain to control the feeding of the displacement, inletting alternating current to a testing electrode and reading the magnitude of the component of 3 omega harmonic collected by the testing electrode through derivation formula calculation. Themethod is simple, and completely meets the requirements of detecting the thermal conductivity of films under different strain and temperatures.

Description

technical field [0001] The invention relates to a micro-electromechanical system (MEMS) device, in particular to a device and method for measuring thermal conductivity of a nano-film under strain and temperature fields. Background technique [0002] With the continuous development and advancement of micromachining technology, as an important development field for the miniaturization of instruments and equipment, MEMS devices have received more and more attention. When the scale of the device / material is miniaturized, due to quantum effects, size effects, and surface and interface effects, many of its physical laws will change compared with those at the conventional scale, that is, micro-scale effects appear. For example, various thin-film materials in MEMS devices are widely used. Due to factors such as technology, microstructure, boundary effects and defects, their physical properties are often different from those of bulk materials, showing obvious micro-scale effects. Th...

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Problems solved by technology

For example, in the patent (publication number CN102053100A) "Automatic measuring instrument for thermoelectric material parameters" (Lin Guocong, Liu Hui, Ding Xidong, Zhang Jinxiu), an instrument was invented that can automatically measure thermoelectric materials within the temperature range of -30° to 800° The electrical conductivity, Seebeck coefficient, and thermal conductivity at each temperature point can be used to obtain the quality factor ZT of thermoelectric materials. However, this type of system is complex and expensive to build, and does not involve the measurement of mechanical and thermal coupling parameters, which still cannot meet the needs.

[0004] For example, the document Mechanical Strain Dependence of Thermal Transport in Amorphous Silicon Thin Films (Nanoscale & Microscale Thermophysical Engineering, 2015) proposed a MEMS-based nanostructure stretching device, and derived thermal conductivity through theoretical derivation, but did not consider thermal conductivity at different temperatures Measurement

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