Heat-type wind-speed and wind-direction sensor with heat insulation structure and preparation method thereof

Abstract

The invention discloses a heat-type wind-speed and wind-direction sensor with a heat insulation structure, comprising a silicon chip and a ceramic substrate, wherein the silicon chip is positioned above the ceramic substrate; four heating elements and four heat-sensing temperature-measuring elements are symmetrically distributed on the four edges of the upper surface of the silicon chip; a heat insulating groove is arranged between each heating element and each heat-sensing temperature-measuring element; heat insulating cavities are arranged below the heat-sensing temperature-measuring elements at the back of the silicon chip; and a ceramic gold-plating layer and a silicon gold-plating layer are arranged between the silicon chip and the ceramic substrate and are connected by adopting a gold-gold bonding process so as to be used for the heat connection between the silicon chip and the ceramic substrate. In the whole preparation process of the sensor, a standard CMOS (complementary metal-oxide-semiconductor) process is used, the after-treatment process is simple, and the prepared heat-insulating groove and the heat insulating cavities can be used for increasing the sensitivity of the chip effectively, reducing the heat conduction loss of the chip and the heat capacity of the sensor, and reducing the response time of the sensor.

Description

technical field [0001] The invention relates to a thermal wind speed and direction sensor with a heat isolation structure and is compatible with a standard CMOS process, in particular to an integrated wind speed and direction sensor with low power consumption and a preparation method thereof. Background technique [0002] In the design of CMOS integrated wind speed and direction sensor, there are two factors that limit its development. On the one hand, there is the problem of packaging. The sensor packaging material requires good thermal conductivity and protection for the sensor, and the design also needs to take into account the impact of the packaging material on sensor sensitivity, reliability, and price. This limits The degree of freedom of the sensor's own packaging design is limited, and the thermal flow sensor requires the sensitive part of the sensor to be exposed to the measurement environment, and at the same time requires the processing circuit to be isolated fro...

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Problems solved by technology

As a result, silicon wafers are easily subject to various contaminations, resulting in unstable performance and even damage.

If a ceramic substrate with high thermal conductivity is used, and the silicon chip of the sensor is packaged by flip-chip packaging or thermally conductive adhesive, the above contradictions can be better avoided, but the heat generated by the sensor after packaging is extremely large. Part of it is dissipated from the silicon-based substrate in the form of heat conduction, and only a small part is heat-exchanged with the outside air through the ceramic, which greatly reduces the amplitude of the output sensitive signal, and the sensitive signal can be improved by increasing the power consumption of the sensor. amplitude, but it causes a large power consumption of the entire sensor system

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