利用PZT圖形定義提升封閉式壓電麥克風感測靈敏度

Improve Sensitivity of MEMS Piezoelectric Clamped Microphone Utilizing Patterned PZT Structure

黃俊隆(Huang, Jun Long)

指導教授 ： 方維倫

國立清華大學/工學院/動力機械工程學系/碩士(2016年)

摘要

本研究主要利用PZT壓電薄膜搭配SOI的製程平台進行壓電麥克風的製作與實現，並提出不同於典型的結構設計以提升微機電壓電麥克風的感測靈敏度，從結構上的設計增加薄膜產生的應力分布，再透過感測電極的配置讀取訊號，透過有限單元法的模擬的方式進行設計，再由LEM得到壓電式麥克風在聲學上受到背腔的頻率響應與輸出量值大小的趨勢，同時自行製作後端感測的放大電路讀取麥克風元件訊號輸出。麥克風量測平坦區的頻寬約落在213~20k Hz，訊雜比達到65.16dB，相比於典型設計有顯著的增加。最後也針對壓電麥克風感測靈敏度對溫度變化的漂移，經由量測在溫度上升60°C，麥克風訊號輸出有約20%的漂移。

關鍵字

微機電技術 ； 壓電材料 ； 麥克風

並列摘要

This study proposes sensitivity improvement for MEMS piezoelectric microphone to increase signal to noise ratio. Using finite element analysis and lumped element modal design the microphone structure. And piezoelectric microphone devices were fabricated on lead zirconate titanate (PZT) material and Silicon-on-Insulator (SOI) process. Additionally, charge amplifier circuit increase output signal to detect. After fabrication, measuring the performance of designed microphone and comparing with typical type microphone to verify the feasibility of design. Measurement results show a flat acoustic response between 213Hz~20kHz. The sensitivity of microphone is -25dB (ref. 1V/1Pa) and signal to noise ratio is 65.16dB at 1 kHz which is higher than typical type microphone. Last, the sensitivity variation is about 20% by temperature increasing at ΔT= 60°C.

並列關鍵字

MEMS ； Piezoelectric material ； Microphone

參考文獻

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