Device and method for testing thermal parameters of micro-bolometer

Abstract

The invention discloses a device for testing thermal parameters of a micro-bolometer. The device comprises a power source, a test circuit, a data acquisition card, a PC (personal computer) and an evacuating device. The test circuit comprises two operational amplifiers, a current-limiting resistor, a four-wire measuring terminal, a standard resistor, a capacitor and a multi-way switch; the constant-voltage power source is connected with input ends of the two operational amplifiers; an output end and a negative output end of the first operational amplifier are connected with each other and then are connected with the current-limiting resistor, the current-limiting resistor is connected with a first high end of the four-wire measuring terminal, a second high end of the four-wire measuring terminal is connected with a first switch, and a second low end and a first low end of the four-wire measuring terminal are connected with a second switch and a third switch; the standard resistor and the capacitor are arranged between a negative input end and an output end of the second operational amplifier in a parallel connection manner, one end of the standard resistor and one end of the capacitor are connected with the first low end, and the other end of the standard resistor and the other end of the capacitor are connected to a fourth switch; the four switches are connected into the data acquisition card in parallel and are connected with the PC by USB (universal serial bus). A method for testing the thermal parameters includes setting corresponding voltages and resistance; evacuating the micro-bolometer; sampling and outputting voltage values to the PC; calculating thermal response parameters by the aid of thermal response curves.

Description

technical field [0001] The invention belongs to the field of optoelectronic technology and test and measurement technology, in particular to a device and method for testing thermal parameters of a microbolometer. Background technique [0002] Infrared imaging technology is a technology that reflects the thermal radiation on the surface of an object and its internal heat dissipation information. It has been widely used in military and civilian fields. It is an extension of people's vision outside the visible light band. world information capabilities. An important research field of infrared imaging technology is the research of uncooled infrared detector (microbolometer). [0003] The microbolometer is mainly responsible for converting the invisible infrared radiation into a visible electrical signal, and the target to be measured can be imaged through the back-end system signal processing. As a key component of the infrared thermal imager, the microbolometer's performance ...

AI Technical Summary

Problems solved by technology

The multimeter measurement method adopts two-wire measurement, and the measured resistance is connected in series with the test wire. When the measured resistance is relatively small, the test wire resistance and contact resistance cannot be ignored, otherwise it will bring a large measurement error; four-wire constant current The method can eliminate the influence of the test lead resistance and contact resistance on the measurement results, but the measurement accuracy depends on the stability of the constant current source, especially the test current required for high resistance measurement is very small, and it is difficult to be affected by ambient temperature changes. Maintain temperature, so this method is only suitable for high-precision measurement of low and medium resistance resistors

The constant voltage test method will generate a large current when measuring a small resistance, which will cause the resistance value to change due to self-heating of the measured resistance and reduce the test accuracy, so it is not suitable for the measurement of low resistance values; the large pulse current measurement method can control the flow through the measured resistance. The average current of the measured resistance can reduce the problem caused by the self-heating of the measured resistance, but due to the pulsating current flowing through the measured device, this method is only suitable for the measurement of pure resistance, not suitable for the test of inductive devices

In addition, resistance is generally measured by applying a DC signal, and there is inevitably an offset in the DC path, and the offset is quite sensitive to the ambient temperature. In order to improve the measurement accuracy, only expensive devices or complex Temperature Compensation Measures

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