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Sn/Au eutectic based chip partial vacuum packaging method of resonance type pressure sensor

A pressure sensor and sensor chip technology, which is applied to the measurement of the properties of piezoelectric devices, etc., can solve the problems of reduced sealing vacuum, shortened service life of sensor chips, and unenvironmental protection, so as to improve vacuum and reduce heat. impact effect

Active Publication Date: 2010-09-01
NO 24 RES INST OF CETC
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

This method has two defects: 1) the airtightness after packaging is not good, resulting in low vacuum degree after packaging; 2) due to the high sintering temperature of glass, it has a great impact on the thermal shock of the chip, which leads to the service life of the sensor chip decrease
This method has the following disadvantages: 1) the bonding area of ​​the upper and lower chips is small, and the application of solder paste is inconvenient; 2) tin-lead solder is generally used, and lead is poisonous and not environmentally friendly; 3) organic Solvent decomposition will generate a large amount of impurity atmosphere. As the solder paste melts, the impurity gas is wrapped in the molten solder paste, and the sintering airtightness becomes poor, thereby reducing the vacuum degree of its seal, resulting in low yield of partial vacuum packaging ( Generally only 80%)

Method used

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  • Sn/Au eutectic based chip partial vacuum packaging method of resonance type pressure sensor
  • Sn/Au eutectic based chip partial vacuum packaging method of resonance type pressure sensor
  • Sn/Au eutectic based chip partial vacuum packaging method of resonance type pressure sensor

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Embodiment Construction

[0042] The specific implementation manner of the present invention is not limited to the following description, and the method of the present invention will be further described below in conjunction with the accompanying drawings.

[0043] 1. Form a TiW / Au ring 5 with a thickness of 3-10 μm and a ring width of 100-200 μm on the sensor silicon wafer 3 to be subjected to deep groove etching on the back side and release movable parts on the front side, and perform deep groove etching and release movable parts The steps in part 6 include:

[0044] (1) The sensor silicon wafer 3 to be subjected to deep groove etching on the back and release of movable parts on the front figure 1 as shown, figure 1 1 indicates that silicon is prepared to be etched on both sides of the resonant beam of the sensor to release the area forming the resonant beam, and 2 indicates the area on the back of the silicon chip of the sensor where silicon is prepared to be etched in deep grooves. Use the genera...

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Abstract

The invention relates to a Sn-Au eutectic based chip partial vacuum packaging method of a resonance type pressure sensor. In the method, a Sn / Au layer is deposited by electroplating and sputtering, isothermy solidification and eutectic reaction of gold-tin alloy when heated are used to realize partial vacuum packaging, and the yield of the partial vacuum packaging can be raised to 99%. Compared with conventional tin-lead eutectic sintering and silicon glass partial vacuum packaging methods, the method has the advantages of excellent thickness uniformity of the Sn / Au layer, improved service life of a sensor chip and the like and is a novel chip partial vacuum packaging method. The invention is applicable to the field of a movable part partial vacuum packaging of a microelectro mechanical system (MEMS).

Description

technical field [0001] The present invention relates to a kind of method that carries out vacuum encapsulation method to the partial parts of MEMS chip on microelectromechanical system (MEMS) chip, particularly a kind of resonant type pressure sensor chip local vacuum encapsulation method based on gold-tin eutectic, and it directly applies The most important field is the field of partial vacuum packaging of MEMS movable parts. Background technique [0002] At present, in the vacuum packaging technology of resonant pressure sensors, the main methods of vacuum packaging are: [0003] 1. Silicon glass partial vacuum packaging technology. This technology is to coat a certain thickness of glass paste on one of the two chips, and then heat and melt the glass paste in the silicon-glass bonding equipment to realize the sealing of the two chips. This method has two defects: 1) the airtightness after packaging is not good, resulting in low vacuum degree after packaging; 2) due to th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01L1/16
Inventor 张志红熊化兵何开全朱虹娇赵光辉李茂松胡琼
Owner NO 24 RES INST OF CETC
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