Studies on Integration and Packaging Technologies for Health Information Monitoring Microsystems

为了实现人体健康和疾病预防的无线生物监测微系统，近两年来人们一直在研究传感器和电路的集成和封装技术。构建由三个心电检测电极、一个放大器和发射器组成的心电监测微系统是该项目的最终目标之一，该系统可以安装在胸部。利用日本电气工程研究所的多芯片集成电路维修项目，设计并制作了两种定制的脉宽调制和调频发射机和功放。用分立电路设计并制作了腕部继电器发射机的锁相环解调电路。FM型系统具有较好的心电信号质量，而PWM型系统抗噪声能力较差。为实现消化道监测的微胶囊，研制了压力、温度和pH传感的多微传感器芯片。微芯片的设计考虑到了封装。利用定制集成电路设计并制作了pH传感器的检测和脉宽调制传输电路。为了实现系统的微封装，开发了稀释HF溶液的低温SiO_2-SiO_2键合技术。键合是在室温下完成的，但在完成键合之前需要24小时。将键合温度提高到60ﾟC或80ﾟC可有效地缩短键合时间。研究表明，通过高频键合可以实现密封封装。

Integration and packaging technologies of sensors and circuits to realize wire-less bio-monitoring microsystems for human health care and sick prevention have been studied these two years.Fabrication of the ECG monitoring microsystem consists of three ECG detecting electrodes, an amplifierand transmitter, which can be set at the chest is one of the final goals of the project. Two types custom IC of transmitter of PWM and FM, and amplifier were designed and fabricated using the multi-chip IC service project of the Institute of Electric Engineering of Japan. The demodulation circuit using PLL for the relay transmitter set at the wrist was also designed and fabricated with the discrete circuits. It is going to be fabricated with custom IC.The FM type system showed better ECG signal quality but the PWM type system stands up the noise. The muiti-microsensor chip of pressure, temperature and pH sensing was fabricated for realizing micro capsule for the monitoring of the digestive tract. The micro chip was designed considering the packaging. The detection and PWM transmission circuit of pH sensor was also designed and fabricated with custom IC.In order to realize the micropackaging of the systems, low temperature SiO2-SiO2 bonding technology using diluted HF solution have been developed. The bonding was achieved at the room temperature but 24 hours is necessary before the bonding completed. Elevating the bonding temperature to 60ﾟC or 80ﾟC is effective to reduce the bonding time. It is investigated that the hermetic seal packaging can be realized by the HF bonding.