氣膠沉積法應用於堆疊多層微型壓電揚聲器之研製

The Design and Fabrication of Multilayer Piezoelectric Micro Speakers Based on Stacked Film Aerosol Deposition Method

鄒萬新(Wan-Hsin Tsou)

指導教授 ： 吳文中

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202202680

摘要

隨著聲學產業的發展，揚聲器被廣泛使用於日常生活中，包括電腦、手機和耳機等，為了增加使用上的便利性，許多電子產品也走向微型化，倘若微型揚聲器能在結構調整和元件幾何設計，使得以較低電壓驅動並補足低頻聲壓不足之缺陷，對於往後的應用上會有更大的突破性。
本研究以開發壓電致動微型揚聲器為目的，分別為雙壓電單層揚聲器和雙壓電多層堆疊揚聲器，探究兩者結構的差別其輸出表現的結果。元件設計則是透過COMSOL進行致動器結構設計和聲學模擬，找出一個最佳化的尺寸規格；實作方面利用本團隊所開發的氣膠沉積法和金屬微機電製程，並將所有壓電揚聲器元件作組裝。
密閉音場實際量測結果顯示，在1 kHz內，雙壓電單層揚聲器聲壓位準皆可達97.4 dB (30 Vpp)以上，最高為98.4 dB (30 Vpp)；雙壓電多層堆疊揚聲器聲壓位準皆可達97.2 dB (15 Vpp)以上，最高為102.2 dB (15 Vpp)，驗證透過調整結構並保持在相同的總壓電層厚度下，多層堆疊結構(15 Vpp)可以有效降低驅動電壓，即可達到和單層結構(30 Vpp)相似的聲壓位準。

關鍵字

壓電揚聲器 ； 致動器 ； 氣膠沉積法 ； 多層堆疊 ； 聲壓位準

並列摘要

With the progressive development of acoustic technology, speakers are widely used in daily life like computers, smartphones and headphones, etc. In order to increase the convenience of using, a lot of electronic products are gradually miniaturized. If the micro-speaker can be adjusted in the structure and the geometric design to make up the sound pressure level by lower applied voltage in the low-frequency region, it will bring outstanding prospects for application.
The purpose of this research is to develop forward-looking piezoelectric actuated micro-speakers, and to carry out the bimorph of the piezoelectric single speaker and bimorph of the multilayer speaker, exploring the difference between the two structures in their output performance. In terms of the design of components, we use COMSOL to find the optimized specification, including actuator geometry and acoustic simulation. As part of device implementation, we use the aerosol deposition method and metal MEMS process developed in the past by our laboratory, and assembling all piezoelectric speaker components.
The experimental measurement results of the enclosed field reveal that the sound pressure level of bimorph of the piezoelectric single speaker can reach more than 97.4 dB, and the highest is 98.4 dB by 30 Vpp applied voltage； bimorph of the piezoelectric multilayer speaker can reach more than 97.2 dB, and the highest is 102.2 dB by 15 Vpp applied voltage. Thus, it is verified that the sound pressure level of the multilayer by 30 Vpp applied voltage is similar to the single by 15 Vpp applied voltage with adjusting the structure and maintaining the total piezoelectric layer thickness.

並列關鍵字

piezoelectric micro speaker ； actuator ； aerosol deposition method ； multilayer ； sound pressure level

參考文獻

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