表面聲波元件理論模擬以及溫濕度與紫外光波段感測器研發

Theoretical Analysis of SAW Device and Application as Temperature, Humidity and UV Sensors

蔡奇儒(Chi-Ju Tsai)

指導教授 ： 馬劍清

國立臺灣大學/工學院/機械工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.00918

摘要

表面聲波元件具有靈敏、體積小、製程簡單等優勢，在感測器領域有相當廣
泛的應用，在溫度、氣壓、濕度、小分子感測等等皆有相當多的商用產品開發以
及研究成果。除了感測器外，由於表面聲波元件有較高的Q-factor，其中心頻率的
能量相當明顯，在通訊方面應用為相當重要的濾波器，因此也對生活帶來更多便
利性。
表面聲波元件由壓電基板、指叉電極、感測區所構成，在本文中首先建立表
面波基本理論模型，並且選擇不同壓電基板製作表面聲波元件，探討各種元件之
頻率響應對於溫度變化的敏感度，另外在溼度感測方面，本研究探討液體負載對
於壓電基板的影響，並且利用致冷晶片將表面聲波元件降溫至露點溫度以量測環
境濕度。
除了溫度與濕度外，本研究也探討表面聲波元件於紫外光感測的應用，在表
面聲波元件之延遲線上濺鍍上一層約6000

關鍵字

表面聲波元件 ； 紫外光感測 ； 斜指叉電極 ； 溫溼度 ； 氧化鋅

並列摘要

In this research, IDT is developed on piezoelectric substrate LiNbO3, Quartz and
LiTaO3. The insertion loss of the device is measured and is compared with the
impulse-function model. In the temperature experimental result, the center frequency
of SAW device is shifted from temperature perturbation.Tthe sensitivity of the SAW
device for temperature is in the order of 10-2°C.
In general, the velocity or insertion loss of SAW device is affected by
acoustoelectric interaction and mass loading. Consequently, Zinc-Oxide is developed on
LiNbO3 substrate in order to generate photoelectric effect with UV light. In this research,
a SAW device with UV detecting area is fabricated, the light wave length between
330nm and 400nm is analyzed, and a sensitivity in the order of W / cm2 is found. It
is note that the dynamic response of SAW light sensor is excellent for 400nm light
length. By combing slanted finger interdigital transducers and plural optically active
areas, an array photodetector can be achieved. This array photodetetor can obtain
multiple UV light intensities within a single measurement.
Finally, we discuss the effect of liquid loading and the vapor in the air condense
into dew on the SAW device surface, A humidity sensor is developed by using cooling
chip to cool down the SAW device to the dew point temperature. By measuring the dew
point temperature and room temperature, the humidity is obtained from SAW humidity
sensor with high accuracy.

並列關鍵字

SAW device ； UV sensor ； Slanted IDT ； Temperature-humidity ； Zinc-Oxide

參考文獻

黃采如，馬劍清,”表面聲波元件應用於光感測器之設計、分析與量測,”博士論文,

余志明，馬劍清,”寬頻表面聲波元件於陣列式光感測器之應用,”碩士論文,機械工程

何亞倫，吳政忠,”表面聲波式微液珠控制系統之研製及其於核酸增幅反應之應用,”

王偉姍，吳政忠,”結合聲電效應之版波與表面聲波感測器研製,”博士論文,應用力學

Wang, W, S., Wu, T. T., Chou, T. H., and Chen, Y. Y., "A ZnO nanorod-based SAW