Method for determining effective thermal conductance of micro-bolometer

Abstract

An embodiment of the invention discloses a method for determining the effective thermal conductance of a micro-bolometer. The method includes: building a three-dimensional simulation model of the micro-bolometer; importing the parameters of the micro-bolometer into the three-dimensional simulation model; loading simulation constant current on the three-dimensional simulation model, loading a simulation dynamic thermal radiation pulse after simulation temperature is stabilized, and using a thermoelectric coupling finite element simulation method to obtain data of temperature rise change along with time; acquiring an effective thermal time constant according to the data; calculating the effective thermal conductance of the micro-bolometer according to the effective thermal time constant. The method has the advantages that the method is based on the precise three-dimensional simulation model, the actual size and processing line parameters of the micro-bolometer are used, device working states are simulated in real through finite element dynamic thermoelectric coupling analysis so as to calculate the effective thermal conductance of the micro-bolometer, and the calculated effective thermal conductance is more accurate than the effective thermal conductance theoretically calculated.

Description

[0001] technical field [0002] The invention relates to the technical field of infrared detectors, in particular to a method for determining the effective thermal conductivity of a microbolometer. [0003] Background technique [0004] The working principle of the microbolometer is that the light-absorbing layer receives external infrared radiation to cause the temperature of the device to change, and the temperature change causes the resistance of the sensitive film to change. The change in electrical properties is detected by the electrode and transmitted to the readout circuit to complete the signal. processing and imaging. There are many parameters that affect the performance of microbolometers, including heat capacity, thermal conductivity, thermal time constant, infrared effective radiation area received, temperature coefficient of resistance of heat-sensitive film, noise, etc. [0005] From the working principle of the microbolometer, it can be known that under the...

AI Technical Summary

Problems solved by technology

[0016] The disadvantages of this method are: (1) This method requires the device to work in a DC state, that is, f=0HZ, to be more accurate. When the current is in a pulse state, this method will have a huge error; (2) This method There is an approximation for the flat band part of the curve, which will affect the effective thermal conductivity value to a certain extent

[0017] Therefore, the existing methods for determining the effective thermal conductivity of the micro-bridge structure of the microbolometer all affect the accuracy of the thermal parameters of the microbolometer to a large extent, and a more accurate method for determining the effective thermal conductivity is needed

Images