應用於血壓量測之線性化電容式觸壓感測器

本研究開發出一種應用於血壓量測的線性響應電容式觸壓感測器。研究首先使用有限元素法模擬得到結構最佳化的三組懸臂設計，並採用一組傳統平板電容結構以作對照。製程採用TSMC 0.35μm CMOS-MEMS製程，結合自行開發的金屬溼蝕刻後製程完成元件開發。量測採用阻抗分析儀(Impedance analyzer)進行理論驗證，再配合RC鬆弛振盪器(RC relaxation oscillator)、電容-電壓轉換器(Capacitance-Voltage converter)兩應用電路量測。量測結果顯示本研究的三組線性響應設計，均具有較高的線性度，此感測器性能可達到0.990的線性度(非線性度4.91% )，消除傳統式平板電容62.97%的非線性度(從13.26%至4.91%)，同時提高36.36%的感測範圍(從165mmHg至225mmHg)，並有效降低因多層結構內部殘餘應力造成的翹曲現象。本研究並採用覆晶封裝(flip-chip packaging)對元件結構進行封裝，初步功能性測試結果顯示封裝電性正常。

關鍵字

電容式觸壓感測器； CMOS-MEMS製程；線性度；覆晶封裝

並列摘要

A linear-response capacitive tactile sensor for blood pressure measurement was developed in this work. FEM (Finite Element Method) simulation was utilized to obtain three optimized structure designs, with one conventional parallel plate capacitor design for comparison. The TSMC 0.35μm CMOS-MEMS process along with the self-developed metal wet-etching process was employed to realize the structure. The sensor was measured by the impedance analyzer for theoretical verification. Two discrete electronic circuits, the RC relaxation oscillator and the capacitance-voltage converter were used to measure the response. Measurement results showed that the three linear-response designs demonstrated higher linearity than the conventional one. The linearity was improved to 0.990 (nonlinearity 4.91%), which eliminated 62.97% of the nonlinearity in the conventional design (from 13.26% to 4.91%). In the meantime, the dynamic range was enhanced 36.36% (from 165 mmHg to 225mmHg). The buckling of the membrane due to the residual stress in the multi-layer structure was also alleviated. The packaging of the sensor was realized by the flip-chip packaging, and was proved to be successful by the preliminary functional test.

並列關鍵字

Capacitive tactile sensor ； CMOS-MEMS process ； Linearity ； Flip-chip packaging

參考文獻

[1] G. Subcommittee, "1999 World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension," Journal of Hypertension, vol. 17, pp. 151-183, 1999.

[2] World Health Organization (WHO), "World Health Statistics," 2012.

[3] F. P. Cappuccio, S. M. Kerry, L. Forbes, and A. Donald, "Blood Pressure Control By Home Monitoring: Meta-Analysis Of Randomised Trials," BMJ: British Medical Journal, vol. 329, pp. 145-148, 2004.

[4] R. Agarwal, J. E. Bills, T. J. W. Hecht, and R. P. Light, "Role of Home Blood Pressure Monitoring in Overcoming Therapeutic Inertia and Improving Hypertension Control," Hypertension, vol. 57, pp. 29-38, 2011.

[5] B. Gupta, "Invasive Blood Pressure Monitoring," World Federation of Societies of Anaesthesiologists, 2007.

國際替代計量

應用於血壓量測之線性化電容式觸壓感測器

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