无引线封装高温压力传感器

Leadless Packaging High-Temperature Pressure Sensor

研究的压力敏感芯片利用单晶硅的压阻效应原理制成；采用绝缘层上硅（S01）材料取消了敏感电阻之间的pn结，有效减小了漏电，提高了传感器的稳定性；用多层复合电极替代传统的铝电极，并应用高掺杂点电极技术，提高了传感器使用温度。封装时，将硅敏感芯片的正面与硼硅玻璃进行对准气密静电键合；在硼硅玻璃的相应位置加工引线孔，将芯片电极和管壳管脚用烧结的方法实现电连接，形成无引线封装结构。采用无油封装方法，避免了含油封装中硅油耐温能力差的问题。对高温压力敏感芯体结构进行了热应力分析，并对无引线封装方法进行了研究。对研制的无引线封装高温压力传感器进行了性能测试。测试结果与设计相符，其中传感器的测量范围为0—0．7MPa，非线性优于0．2％FS，工作温度上限可达450cC。

Sensor chips was proposed based on the piezoresistive-effect of single crystalline silicon. Silicon on insulator （SOI） was applied to reduced leakage current and improved stability effectively by eliminating of the pn junctions. High doping-point electrode and multi-metal-layer composite electrode technology were used in the senor to fit the high operating temperature. In packaging, a glass cover was attached to the sensor chip hermetically and aligned using electrostatic bonding, through the holes were micromachined at right site in the glass cover to connect electrodes and contact pins of the sensor header, so this is the leadless packaging. The poor heat resistance of silicon oil was avoided with the oil-free package. Thermal stress of high-temperature pressure chip was analyzed and the leadless package method was studied. Performances of the high-temperature pressure sensor with leadless packaging was tested. The results of measurement and acoustic design were close. The measurement range of the sensor is 0-0.7 MPa and the nonlinearity is less than 0.2%FS, and the operating temperature is up to 450 ℃.