Wafer-level packaging method based on silicon molecular sieve and polytetrafluoroethylene composite film

Abstract

The invention discloses a wafer-level packaging method based on a silicon molecular sieve and polytetrafluoroethylene composite film. By using a silicon-on-insulator wafer as a carrier, the method integrates the vacuum packaging of a temperature sensor chip on a wafer, and the dustproof and chemical adhesion-proof open-type packaging of a humidity sensor chip and a pressure sensor chip on the wafer into one set of technology via technologies such as dual-surface photolithography, deep-hole etching, surface spin-coating, eutectic bonding, and so on. Top silicon of the silicon-on-insulator wafer is used as an etching carrier to prepare the molecular sieve used as a packaging window of the humidity sensor and the pressure sensor to block impurity particles with large size in the air. Through a surface modification technique, the polytetrafluoroethylene film covers the surface of the silicon molecular sieve to perform hydrophobic treatment to effectively improve anti-adhesion performance of the surface. A micro electro mechanical gas sensor adopting the packaging technique not only could be applied to a complex chemical impurity environment to achieve accurate industrial process monitoring, but also has remarkable price and volume advantages and is suitable for industrialized mass production simultaneously.

Description

technical field [0001] The invention belongs to the technical field of micro-electromechanical systems (MEMS) manufacturing, and in particular relates to a wafer-level packaging technology for dust-proof and chemical-impurity-proof multi-parameter microsensors of temperature, humidity and pressure. Background technique [0002] As modern industry moves towards the 4.0 era, process control plays an increasingly important role in production. Usually, in order to ensure that the production process is in a controlled state, the parameters that directly or indirectly affect product quality, such as temperature, humidity, pressure, flow, liquid level, composition, concentration, etc., are detected and controlled in real time to make them close to a given value or maintain within the given range. Through the control of process parameters, production efficiency can be improved, energy consumption can be reduced, pollution can be reduced, etc. However, for chemical, petroleum, meta...

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Problems solved by technology

In view of the fact that there is no relevant report on the dust-proof and chemical-contaminated wafer-level packaging of MEMS devices, the present invention proposes a temperature,

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