Piezoresistive pressure sensor chip adopting face down bonding and preparing method thereof

Abstract

The invention relate to a micro electro mechanical system (MEMS) device, and provides a piezoresistive pressure sensor chip adopting face down bonding, which is high in reliability, can avoid inconsistency of varistors and solves the problem that a metal wire for connecting the piezoresistive pressure sensor chip with an external circuit is likely to break, and as well as a preparing method of the piezoresistive pressure sensor chip. The piezoresistive pressure sensor chip adopting face down bonding is provided with a chip main body; the chip main body is provided with a silicon substrate with a square pressure cavity and a silicon membrane; a varistor is arranged on the surface of the silicon membrane; the silicon substrate is combined with the silicon membrane through direct silicon-silicon bonding; the piezoresistive pressure sensor chip is welded on a printed circuit board (PCB) through adopting face down bonding method; and the varistor and three resistors with the resistance values being the same as that of the varistor of the external circuit form an integral comparison bridge. In preparing, the silicon substrate part is prepared at first, and then is assembled and subjected to follow-up process, and is finally is connected with the external circuit of the chip.

Description

technical field [0001] The invention relates to a micro-electromechanical system (MEMS) device, in particular to a piezoresistive pressure sensor chip using flip-chip welding and a preparation method thereof. Background technique [0002] Micro electromechanical system (Micro electro mechanical system, MEMS American idiom), also known as microsystem (European idiom) and micromachine (micromachine, Japanese idiom), is an emerging technology that has developed rapidly in the past 20 years. It refers to Designed in the micron level, integrated with silicon micromachining and precision machining and other micromachining technologies, integrated a variety of components, and suitable for low-cost, mass-produced systems. MEMS is usually composed of sensors, information units, actuators, and communication / interface units. Among them, various sensors obtain information such as light, electricity, sound, pressure, and temperature from objects that need to be observed and controlled, a...

AI Technical Summary

Problems solved by technology

However, although the piezoresistive pressure sensor is already a very mature commercial product, the MEMS piezoresistive pressure sensor chip as its core is poor in consistency due to its piezoresistor and is used to integrate the piezoresistive pressure sensor. The metal wire connecting the chip and the external circuit is easy to break and other problems limit the wide application of MEMS piezoresistive pressure sensors

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