减小压力变送器漂移的方法

Methods to Reduce Drift of Pressure Transducers

扩散硅压力芯片和硅环基座封接采用金硅共熔工艺,硅环通过引压管和底座封接,整个力敏器件的结构是浮动式,这样大大减小了芯片周围的应力。芯片外面是充满硅油的膜盒腔。扩散硅芯片内引线采用高掺杂浓度导电带,外引线用金丝,热压焊和超声焊相结合,保证接点有良好的导电性能。这些措施减小了压力变送器的时漂,提高了可靠性。变送器的零点和灵敏度热漂移经过外电路补偿后显著降低。通过两种不同的外电路分别组成电压电流输出的压力变送器,在-20～70℃范围内,准确度为±0.5％F.S,输出信号可为0～5V,4～20mA,1～5V。可广泛用于宇航,石油化工等领域测气体、液体介质的压力。

The diffused silicon chip is bonded on the silicon -ring base by gold -silicon fusion technique, and silicon-ring is bonded on the base by the pressure inlet tube. The whole pressure device is of floating construction, which largely reduces the stress around the chip. Outside the chip is a membrane chamber fully filled with silicon oil. The chip is inner - connected with heavily doped conduction belt and external-connected with gold wire by the combination of hot welding and ultrasonic welding which ensures good conducting propertes at contacting dot. These methods reduce the time drift of the device and increases the reliability. Zero drift and sensitivity temperature drift of the transducer are obviously decreased with the external circuits compensating. By two kinds of external circuits, the current and voltage pressure transducers are formed respectively. In the range of -20～70℃ , the accuracy is ±0.5% F. S, output signal are 0- 5V, 4 - 20mA, 1 -5V. The device can be widely applied in the fields such as space navigation, petrochemical industry for measuring the pressure of gas and liquid medium.