A high temperature pressure sensor packaging structure

Abstract

The invention relates to a package structure of a high-temperature pressure sensor, comprising a silicon carbide sensitive chip, an aluminum nitride base, a stress buffer substrate, a high-temperature sealing glass, a lead post, a Kovar outer cover and a thermocouple, wherein the aluminum nitride base is There is a boss on the surface, a stress buffer substrate is placed on the boss, and a silicon carbide sensitive chip is placed on the stress buffer substrate; the periphery of the boss is a stress isolation groove, and there are two or more through holes on the periphery of the stress isolation groove. The column passes through the through hole and is sintered by high-temperature sealing glass to realize the fixed connection between the lead column and the aluminum nitride base. The thermocouple is installed on the lower surface of the aluminum nitride base, and the aluminum nitride base is placed on the Kovar housing through the positioning steps. In addition, the aluminum nitride base and the Kovar cover are sintered and connected through high-temperature sealing glass. The packaging structure is resistant to high temperature, effectively reduces the influence of process stress and high temperature thermal stress on the sensitive chip of the MEMS pressure sensor, and further improves the high temperature measurement accuracy of the sensor.

Description

Technical field [0001] The invention relates to a miniature electronic mechanical packaging structure, in particular to a high-temperature pressure sensor packaging device. Background technique [0002] High temperature pressure sensors have a wide range of application requirements in the fields of aviation and aerospace engine combustion chamber pressure monitoring, deep space exploration and modern weapon equipment systems. Due to the particularity of the measurement environment, the sensor is required to be able to withstand high-temperature media environments above 500°C. [0003] The high-temperature pressure sensor based on SiC material is a hot research topic at home and abroad. According to reports, the currently successfully developed SiC pressure sensor chips can work at temperatures as high as 600°C, but these chips can only be evaluated and demonstrated in a laboratory environment for short-term, and there is still a certain distance from commercialization. The main r...

AI Technical Summary

Problems solved by technology

For packaging materials, problems such as oxidation, diffusion, and mechanical property degradation are prone to occur in high-temperature environments, which affect the long-term stability of the packaging body; Thermal stress, on the one hand, can affect the performance of sensitive chips, and on the other hand, it can lead to structural cracking affecting air tightness and metal interconnections

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