Constant-temperature structure for high-performance gas detection device and preparation method

Abstract

The invention discloses a constant-temperature structure for a high-performance gas detection device and a preparation method. The structure comprises a top layer Al3N4 substrate unit, and a TEC unitis integrated on the lower surface of the top layer Al3N4 substrate unit. The top layer Al3N4 substrate unit is formed by stacking more than one layer of perforated Al3N4 substrate in the vertical direction, a thin film gas sensitive resistor is integrated on each layer of perforated Al3N4 substrate, and a via hole of each layer of perforated Al3N4 substrate is filled with a filler. Thick-film thermistors are further embedded in the second layer of punched Al3N4 substrate which is located on the top layer of the top layer Al3N4 substrate unit and faces inwards. The N-type semiconductor and theP-type semiconductor are respectively arranged at two ends of the TEC unit and are connected to the surface bonding region through a channel structure formed by via holes. The thick film thermistor is connected with a controllable bidirectional switch circuit for controlling the current direction of the TEC unit. The temperature drift range of related performance parameter indexes of all components in the gas sensitive device can be reduced, and miniaturization of assembly is facilitated.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a constant temperature structure and a preparation method for a high-performance gas detection device. Background technique [0002] The structure of traditional gas detection devices is mainly to directly mount and paste discrete components such as sensing signal processing chips, gas sensitive resistors, and other active / passive components on aluminum nitride ceramic substrates (Al 3 N 4 ), and then perform circuit welding to complete the circuit connection. Its structure is as follows figure 1 shown. However, the gas detection device with this structure has the following problems: the gas-sensitive resistor is only a single-layer surface, and the sensing area for gas is very small, which affects the sensitivity and the sensitivity of the sensing signal; at the same time, the entire device works in a natural environment. As the temperature changes, the electrical and physica...

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Problems solved by technology

However, the gas detection device with this structure has the following problems: the gas sensitive resistor is only a single-layer surface, and the sensing area for the gas is very small, which affects the sensitivity and the sensitivity of the sensing signal; at the same time, the entire device works in a natural environment. As the temperature changes, the electrical and physical properties of each component will change to a certain extent, which will affect the detection accuracy

At the same time, when some limiting devices are used in high-reliability environments or in some special fields such as aerospace, aviation, ships, precision instruments, geological exploration, oil exploration, other field operations, communications, industrial control and other environments with complex temperature changes, in order to To ensure the accuracy of detection, it is necessary to add some bulky and expensive ambient temperature control devices for use

On the other hand, due to the strong temperature selectivity of gas sensitive resistors for different gases, it is necessary to set different working environment temperatures for different detection gases, which brings great inconvenience to the use of the device.

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