高階助聽器晶片及系統---子計畫六：助聽器異質整合技術(I)

Abstract

本計畫我們提出目標在未來3 年開發高效能、低功率之耳道型助聽器。基於我們 先前開發的異質晶片整合技術、相關物理模型及應用於助聽器之微機電式聲學元件的 基礎上，透過本計畫開發之新設計及新技術，將可完全實現一個高效能的耳道型助聽 器系統。在本計畫提出之耳道型助聽器中，聲學元件將被製造在具有兩個具有電氣連 接之矽載具上。其中一組矽載具將被設計為承載信號處理晶片與電源管理系統的平 台，並以覆晶接合技術來整合此些異質晶片，同時，它亦承載著一組擁有不同直徑大 小與不同薄膜材料之的微型喇叭陣列，此陣列設計將使其效能於不頻段之運作達成最 佳化。平台的邊緣會將以電氣與機械方式連接到另一組搭載微機電式麥克風之矽載 具。此連接則是以低溫覆晶接合技術將兩組矽載具與以聚合物基板所製成之電纜線整 合成一個可撓式結構來實現，並使兩個連接的矽載具以形成一個符合耳道形狀的摺疊 結構。此外本計畫提出之仿生式麥克風是基於寄生蠅和四葉草形狀的平衡環設計，具 備全方位聲學反應、小於15度的空間解析度用來降低噪音、10mV/Pa之靈敏度和100dB 動態範圍的能力來達來聲源定位並希冀以CMOSMEMS 晶片製造技術來實現，進而達 成系統單晶片之最終目標；微型喇叭陣列則具有~1V 驅動電將壓，在1kHz 的2c.c.耦 合器產生大於106 dB 級聲壓與功耗小於1mW 的特性；應用於類比電路之設計製作出 在矽載具上之μH 級電感等。在結合先前開發之整合技術，如金-金熱壓式覆晶接合技 術，我們將可以完全實現整合類比感測和驅動電路之聲學組件進而達成一個近乎“單 一”晶片之高效能微型化助聽器系統。本計畫的主要目標研究為：1)開發一種高效能的 聲源定位與具備降噪能力的CMOSMEMS 仿生式麥克風，2)開發低功耗，低失真的微 型喇叭陣列，3)開發應用於異質整合助聽器的可撓式晶片互連結設計架構，與4)用以 最佳化類比電路設計的聲學組件之測試和物理模型。由於最後的助聽系統設計開發是 針對於中文的使用者，我們相信計畫結束時所交付的技術將實現真正鼠屬於台灣的醫 療器材產業。

This proposal presents our goal in the next three-year project regarding the development of high performance, low powered, ITC-typed hearing aids. Based on the unit processes we have developed previously for the heterogeneous chip integration and the characterization and physical model regarding the design and fabrication of MEMS-typed acoustic components for the application of hearing aids, a high performance ITC-typed hearing aid system can be fully realized by implementing new designs and new technologies which will be developed in the project. In the proposed ITC-typed hearing aids, acoustic components will be fabricated on two electrically connected silicon carriers. One of the silicon carriers will be designed as a platform to host signal processing chips and power management system using flip-chip bonding technique and, meanwhile, it also hosts a microspeaker array which are designed with different membrane sizes in diameter with different membrane materials for different frequency response. The edge of the platform will be electrically and mechanically connected to another silicon carrier where MEMS-typed microphones will be directly fabricated. The connection is realized using a flexible cable formed by the technique of low temperature flip-chip bonding to a polymer cable, so that two connected carriers can form a folded-like structure to closely fit with an ear carnal. The proposed biomimetic microphone based on the parasitoid fly and clover-stem-like gimbal design could really have the capabilities of omni-directional sound response, less than 15° spatial resolution for noise reduction, 10mV/Pa sensitivity, and 100 dB dynamic range for sound source localization. The microspeaker array would have the characteristics of ~1Vdriving voltage, >106dB SPL at 1KHz output power at a 2c.c. coupler, <1mW power consumption, μH-order on-carrier inductors for analog circuit applications. Meanwhile via the developed integration technologies, like Au-Au thermal compressive flip chip bonding, we can fully integrate analog sensing and driving circuits with the developed audio components to form a miniaturized hearing aid system onto a “single” chip and make such a system with the performance as well as or even better than the SOC. The primary objectives of the proposed research are: 1) the development of a high performance CMOS MEMS biomimetic microphone with sound source localization and noise reduction abilities, 2) the development of a low power, low distortion microspeaker array, 3) the development of flexible interconnecting scheme for the heterogeneous integration of hearing aids, and 4) testing and physical modeling of the acoustic components for optimum analog circuit design. Since the final hearing aid system is aimed for the users speaking Chinese and will be delivered by the end of this project, it is our belief that the developed technologies will realize a real medical instrumentation industry in Taiwan.