1312638 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種駐極體電容式麥克風（Electret Condenser Microphone, ECM) ’ 尤其是一種結合 了微機 電技術與機械加工製程，而製作出之駐極體電容式石夕 麥克風（Electret Condenser Silicon Niirophone,或簡稱 為駐極體矽麥克風）’以及相關的製作方法。 【先前技術】 麥克風（Microphone )是一種能將聲音轉換為電訊 號以為傳遞的電子產品或零件，屬於一種電聲轉換元 件（Electro-acoustic Transducer)，而依據其轉換聲音之 原理的不同’主要可以區分為（M〇vingc〇il)動圈式、 電容式（Condenser)與壓電式（Piezoelectric)三種。 其中，電容式麥克風因其製造技術發展歷程的改變， 又可區分為傳統電容式麥克風以及駐極體電容式麥克 風。 第一 A圖係顯示一習知電容式麥克風示意圖，用 以解釋電容式麥克風的工作原理。如圖所示，此電容 式麥克風係由一振膜10與一具有開孔14之背板12所 構成。此振膜10與背板12間係相隔一適當距離g，並 通有一偏壓（bias) V以構成一電容器。當外界聲壓 .(Ac_ic pressure)變化導致振膜1〇振動，振膜1〇 6 1312638 與背板12之距離g係隨之改變，而造成此電容器之電 容值（Capacitance)的改變。又此電容值之改變引發一 與聲壓變化量成正比之電流信號。此電流信號經場效 電晶體（Field Effect Transistor，FET )(未圖示）放大後， 即可供偵測與紀錄外界輸入之聲波。 請參照第一 B圖，其係為一傳統電容式麥克風結 構圖。第一 B圖係取自美國第5,490,220號專利文件之 _ 第七圖（FIG.7)，該專利係關於一固態電容式麥克風 (SOLID STATE CONDENSER AND MICROPHONE DEVICE)，可作為本文中已提及的“傳統電容式麥克 風”之代表。可對照第一 A圖與第一 B圖，於該件習 知專利文件中’ 一振膜720係用以作為第一 A圖之振 膜10，而具有複數個開孔766的背板764的功能即等 同於第一 A圖之背板12。值得注意的是其製作方法， 第一 B圖所示之“傳統電容式麥克風”，其各元件之 製作以及後續的組合係採用傳統之機械加工製程，其 ，中’上述之振膜720與背板764皆可為金屬材質，如 第一 B圖’背板764、一外殼714與一基座792共同 組成一背腔室（back chamber) 794，外殼714與基座792 亦可以機械加工製程進行製作。關於背板764與振膜 720之間的偏壓’則是利用外部電壓以在二者間產生電 位差（約200V或以上）以達成。由於需額外耗電以 “外加”偏壓，因此，此特點通常被指稱為‘‘傳統電容 式麥克風”的一項缺點。 1312638 相較之下駐極體電容 “傳統電容式麥克H祕μ制4 %已改。了 日MS-Ύ^-η 而額外耗電的缺點。‘‘駐極體” =-類可，壓而通人電荷之材料的總稱，通入之電 荷可以水久的存麵極體材料之巾 由額外通入電壓而可提供一葙贪认沾广 』小而厶 祕on 士 供預疋的偏壓。關於“駐極 體電今式麥克風，，的_習知技術之制，可參見我 % =H m ί細Γ轉财餘式麥克風之結構 决JrT r。簡&之’請配合第—Α圖，駐極體電容式 麥克風，係將—駐極體材料塗佈或設置於第- Α圖之 振膜10的下表面’或是背板12的上表面，不需額外 的耗電’即可軸f容式麥克風所需的預定偏壓。“駐 極體電容式麥克風，，通常以微機電財式製作，因此可 以大幅縮小麥克風之尺寸’微機電製程所製出之振膜 10係具有機械加卫製賴無法達觸精度，因此不但 對於所欲偵測之聲音（即空氣振動）訊號有更高的敏 銳性’且因加卫之高精度’甚至可在振膜1G上形成特 殊的結構’例如皺折，贿―步加強其效果，此乃機 械加工所無法達成。此外，“駐極體電容式麥克風，，之 振膜10，因所選用的材料不同，因此可較“傳統電容 式麥克風”的振膜（如第一 B圖之振膜724)更耐高 溫，而可經由 SMT(Surface Μ_ technology，表面著 裝技術)以完成元件的組裝，當振膜1〇製作中採用了矽 材時’“駐極體電容式麥克風”又可稱為“駐極體電容式 矽麥克風(Electret Condenser Silicon Microphone)，，，或 1312638 簡稱為“駐極體梦麥克風”。 然而’完全以微機電技術所製作之“駐極體電容式 石夕麥克風” ’通常需要搭配較機械加工製程更為複雜的 封裝程序’封裝成本因此上升。且，以微機電製程進 行後段封震之“駐極體電容式矽麥克風，，，其雜訊屏 蔽效果反倒不如“傳統電容式麥克風，，，其原因為微機 電製程之封裝無法像“傳統電容式麥克風，，之外殼來 • 得厚實，因此雖然振膜10對聲音的感度提高了，但整 體結構的屏蔽效果卻下降，使得雜訊的比例於是提 高。有鑑於上述“駐極體電容式矽麥克風，，所仍然具 有的缺點而加以改善，是為本發明的發展方向。 【發明内容】 本發明之目的係提供一種結合微機電技術與機械 加工製程所製作之駐極體電容式矽麥克風，以及豆 作方法。 、 丨 本發明之另一目的在於提供一種駐極體電容式矽 麥克風，其具有以微機電技術所製作之高精度振膜， 並具有可耐高溫以SMT技術進行組裝的優點。 本發明之另一目的在於提供一種駐極體電容式矽 麥克風，其在背板、前腔室及背腔室處，具有以機械 加工製程所具有的高雜訊屏蔽效果。 本發明之駐極體電容式轉克風，具有—振膜晶 9 用微機電製程所製作之振膜；金屬背板、電路板與金 屬外殼則由機械加工製程製作。金屬背板設置於振膜 晶片之下方，並與振膜間隔一預定距離，金屬背板具 有至少一開孔’用以使平行板電容中的空氣層可與金 屬背板下方之一後腔室相通。電路板係位於金屬背板 之下方，並且電連至金屬背板。外殼用以裝設並保護 振膜晶片與金屬背板，並提供良好的屏蔽效果。外殼 上具有一導音孔，提供一通氣路徑，以使外界聲壓得 以振動振膜，藉此，平行板電容可依振膜之振動而產1312638 IX. Description of the Invention: [Technical Field] The present invention relates to an electret condenser microphone (ECM)', in particular, a combination of microelectromechanical technology and mechanical processing, and produced Electret Condenser Silicon Niirophone (or simply an electret 矽 microphone) and related manufacturing methods. [Prior Art] A microphone (Microphone) is an electronic product or part that can convert sound into a signal to be transmitted. It belongs to an electro-acoustic transducer (Electro-acoustic Transducer), and the difference can be based on the principle of converting sound. It is divided into three types: (M〇vingc〇il) moving coil type, capacitive type (Condenser) and piezoelectric type (piezoelectric). Among them, the condenser microphone can be divided into a traditional condenser microphone and an electret condenser microphone due to the change of its manufacturing technology. The first A diagram shows a schematic diagram of a conventional condenser microphone to explain the working principle of the condenser microphone. As shown, the condenser microphone is constructed of a diaphragm 10 and a backing plate 12 having apertures 14. The diaphragm 10 and the backing plate 12 are separated by an appropriate distance g, and a bias V is applied to constitute a capacitor. When the change in the external sound pressure (Ac_ic pressure) causes the diaphragm to vibrate, the distance g between the diaphragm 1 〇 6 1312638 and the backing plate 12 changes, causing a change in the capacitance of the capacitor. In addition, the change in the capacitance value causes a current signal proportional to the amount of change in sound pressure. This current signal is amplified by a Field Effect Transistor (FET) (not shown) to detect and record the sound waves input from the outside world. Please refer to the first B diagram, which is a conventional condenser microphone structure diagram. The first B diagram is taken from the seventh figure (FIG. 7) of the US Patent No. 5,490,220, which is related to a solid-state condenser microphone (SOLID STATE CONDENSER AND MICROPHONE DEVICE), which can be mentioned as mentioned herein. Representation of "conventional condenser microphones". In contrast to the first A map and the first B graph, in the conventional patent document, a diaphragm 720 is used as the diaphragm 10 of the first A diagram, and the back plate 764 having a plurality of openings 766 is used. The function is equivalent to the back plate 12 of the first A picture. It is worth noting that the manufacturing method, the "conventional condenser microphone" shown in Figure B, the fabrication of the various components and the subsequent combination are carried out by a conventional machining process, in which the above-mentioned diaphragm 720 and back The plate 764 can be made of a metal material. For example, the first B-shaped back plate 764, a casing 714 and a base 792 together form a back chamber 794, and the outer casing 714 and the base 792 can also be processed by a machining process. Production. The bias ' between the back plate 764 and the diaphragm 720' is achieved by using an external voltage to generate a potential difference (about 200 V or more) therebetween. This feature is often referred to as a ''conventional condenser microphone'' because of the extra power consumption required to be "added". 1312638 In contrast to the electret capacitor "conventional capacitive microphone H secret system 4% has been changed. The disadvantage of extra power consumption is MS-Ύ^-η. ''Electret') =----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- "Small and secretive on the pre-biased bias. About the "electret electric microphone", the system of _ conventional technology, see me % = H m ί fine turn to the structure of the microphone JrT r. Jane & 'Please cooperate with the first - diagram, electret condenser microphone, coating or setting the electret material on the lower surface of the diaphragm 10 of the first - or the back plate 12 The surface, without the need for additional power consumption, can be a predetermined bias voltage required for the shaft f-capacitor microphone. "Electret condenser microphones, usually made in MEMS, so the size of the microphone can be greatly reduced." The diaphragm 10 made by the micro-electromechanical process has mechanical reinforcement and can't reach the touch precision, so it is not only for The sound to be detected (ie, the air vibration) signal has a higher sensitivity 'and the high precision of the edifice' can even form a special structure on the diaphragm 1G, such as wrinkles, bribes to enhance its effect, This is not possible with mechanical processing. In addition, the "electret condenser microphone, the diaphragm 10, because of the choice of materials, can be compared to the "conventional condenser microphone" diaphragm (such as Figure B The diaphragm 724) is more resistant to high temperatures, and can be assembled by SMT (Surface Μ_technology, surface dressing technology). When the diaphragm is used in the production of the diaphragm, the 'electret condenser microphone' can be used. It is called "Electret Condenser Silicon Microphone", or 1312638 is referred to as "Electret Mice Microphone". However, "Electrets made entirely by MEMS technology" "Capacitive Capacitor Shixi Microphone" 'usually requires a more complicated packaging process than the machining process' package cost is increased. Moreover, the "electret capacitive 矽 microphone", which is back-sealed by MEMS process, The noise shielding effect is not as good as the traditional condenser microphone. The reason is that the package of the MEMS process cannot be like the “conventional condenser microphone. The outer casing is thicker, so although the sensitivity of the diaphragm 10 to the sound is improved, However, the shielding effect of the overall structure is reduced, so that the proportion of noise is increased. In view of the above-mentioned "electret capacitive 矽 microphone, the improvement still has the disadvantages of the present invention. [Invention] The object of the present invention is to provide a combination of MEMS technology and machining process. The invention relates to an electret condenser microphone and a bean processing method. Another object of the present invention is to provide an electret condenser microphone, which has a high precision diaphragm made by microelectromechanical technology and has The invention is capable of high temperature resistance and assembly by SMT technology. Another object of the present invention is to provide an electret condenser microphone, which has a mechanical processing process at the back plate, the front chamber and the back chamber. High noise shielding effect. The electret capacitive type of the invention has a diaphragm made of a micro-electromechanical process for the diaphragm crystal 9; the metal back plate, the circuit board and the metal casing are made by a mechanical processing process. The metal back plate is disposed under the diaphragm wafer and spaced apart from the diaphragm by a predetermined distance, and the metal back plate has at least one opening 'for making the parallel plate capacitor The air layer can communicate with one of the back chambers below the metal back plate. The circuit board is located below the metal back plate and is electrically connected to the metal back plate. The outer casing is used to mount and protect the diaphragm wafer and the metal back plate, and provide Good shielding effect. The housing has a sound guiding hole to provide a ventilation path, so that the external sound pressure can vibrate the diaphragm, whereby the parallel plate capacitor can be produced according to the vibration of the diaphragm.
1312638 月、一金屬背板、一電路板與一金屬外殼，振膜晶片 與背板組成一平行板電容，平行板電容中利用駐極體 材料而具有一内建之偏壓。其中，振膜晶片具有一利 生相對應之電訊號’藉由電路板將電訊號處理並輸出。 本發明所提供之駐極體電容式石夕麥克風的製作方 法，係首先利用微機電製程製作一振膜晶片。此振膜 晶片之製作步驟包括：（a)製作一振膜材料層於一矽 基板之上表面；⑻去除部分⑪級，轉露振膜材 料層之下表面，（e)製作—振臈電極層於振膜材料層 表面；（d)製作一間隔層圖案於砍基板上。 當分別以微機電餘與機械加卫餘得到本發明 片與金屬背板後’須先行於振膜晶片或金屬 ^表面崎職佈錢合的方式形成駐極體材料 就麟顺二相得辦行板電容。 並於後、，、錄電路板以及金屬核，叹成本發明之 1312638 駐極體電容式矽麥克風。本發明之發展過程係同時著 重於麥克風效能表現的改良、製程成本與製程步驟的 考量，依據本發明，一種極具產業競爭力之駐極體電 容式矽麥克風係被提供。 關於本發明之優點與精神，以及更詳細的實施方 式可以藉由以下的發名詳述及所附圖式得到進一步的 瞭勞。 【實施方式】 請參照第二A與B圖所示，係本發明駐極體電容 式矽麥克風第一較佳實施例之俯視圖與剖面圖。如圖 中所示’本發明所提供之駐極體電容式梦麥克風 具有一平行板電容110、一電路板160與一金屬外殼 180。平行板電容110包括一振膜晶片12〇與一金屬背 板140。其中，振膜晶片120係以微機電（MgMs)製 程所製作’其中包含一振膜122。金屬背板140以機械 加工製程製作’其係設置於振膜122下方一預定距離 處’透過一間隔層圖案124使金屬背板140與振膜122 間保持該預定距離。一駐極體材料層146被利用來形 成平行板電容110内部之一偏壓，駐極體材料層146 可設置於振膜晶片120下表面或金屬背板140上表面。 金屬外殼180用以裝設並容納平行板電容n〇於 其中，如圖所示，金屬外殼180的内部空間主要可因 11 1312638 平行板電谷110而區分為一前腔室s，一空氣層si以 及一後腔室S2。金屬外殼丨⑻具有一通氣路徑，主要 係指圖二B所示之導音孔186，使前腔室s可與外界 之空氣相通，以使外界聲壓得以振動振膜122。電路板 160可設置於金屬背板14〇之下方，並且電連至平行板 電容11〇。平行板電容110可因振膜122受空氣振動 而產生電訊號，電路板160用以將此電訊號放大並輸 出至駐極體電容式石夕麥克風100外部之其它應用裝置。 以上係首先介紹本發明之整體架構，以下則分段 介紹由機械加工製程以製作之本發明金屬背板14〇、電 路板160與金屬外殼18〇,以及，由微機電製程以製作 之本發明振膜晶片120。 金屬背板140具有至少一開孔M4連通空氣層si 與後腔室S2 ’以加強振膜122之振動效果。就一較佳 實施例而言，金屬背板140之開孔率最好係介於5%至 30%。此外，如圖二B所示之實施例，駐極體材料層 146係設置於金屬背板140上表面，設置的方式可為旋 轉塗佈或壓合。此駐極體層材料層146可以係由鐵氟 龍（Teflon)、乙烯丙烯氟化物（FEP)、聚四氟乙烯 (PTFE)與二氧化梦’經電暈充電（corona 所構成。此駐極體材料層146係可内建需要之電位， 而不需要外加電流或電壓’即可在振膜晶片120與金 屬背板140間產生一偏壓（在此情況下，振膜可以係 12 1312638 接地）。又，依此原理，振膜晶月120之下表面亦可以 製作駐極體材料層（未圖示），以内建不同之電位。 本發明關於金屬背板140與駐極體材料層146之 一製作實施例係提供如下：可取一片厚度約0.4毫米之 不錄鋼板’於表面熱壓或旋轉塗一層厚度約1.5微米之 鐵弗龍(Teflon)或12微米之聚四氟乙烯(PTFE)，利用沖 孔方式使不鏽鋼板有16%之開孔率（以形成該些開孔 144)，經電暈充電後，可於不鏽鋼材質表面形成一層永 久帶電之駐極體材料。之後，可另取一壁厚約為0.2毫 米之不鏽鋼環’高度裁切成1毫米，以形成第二B圖 所示之背板導電環142 ’可電連金屬背板140與電路板 160 ’並可架構出後腔室S2之空間。 電路板160具有至少一訊號處理元件162與複數 個接腳164。其中’訊號處理元件162係可設置於電路 板160之上表面’用以放大來自背板140之電訊號（電 流訊號或電壓訊號）’並提供適當之阻抗匹配。接腳 164係位於電路板160之下表面’並且透過至少一導通 孔（未圖示）電連至訊號處理元件丨62，以輸出訊號。 本發明一電路板160詳細實施例係介紹如下： 電路板160之厚度在一實施例中係為〇 3毫米，於 其上表面部份’ §Ηι说處理元件162包含ic或FET以作 為訊號放大用，並包含電容或電阻以作為濾、波或調整 13 Ϊ312638 增益用。1C或FET之一接腳與背板導電環142相連接， 以作為平行板電容110將外部聲音信號產生相對應之 電亂號之電訊號輸入端；另一接腳藉由一外側導電封 膠187連接至金屬侧邊外殼184以及振膜晶片12〇之 電極以形成一完整金屬屏蔽，可阻絕外部電磁干擾。 電路板160之下表面之接腳164,其係由金屬接聊 或錫球構成。電路板160上下兩面之間以貫穿兩面之 金屬層導通，使得聲音訊號所造成的電訊號能經IC或 FET及電阻放大後，藉由接腳164輸出至駐極體電容 式矽麥克風100外部之其它應用裝置。 金屬外殼180係包括一上蓋182、一侧壁ι84、絕 緣内襯188以及外側導電封膠187。上蓋182之中央位 置係具有一導音孔186,以使外界聲壓得通過導音孔 186以振動振膜晶片120。侧壁184由壁厚0.4毫米之 不鑛鋼金屬套桶所構成，側壁184之内緣係設置了絕 緣内襯188，以避免金屬背板14〇與金屬外殼18〇相接 觸’絕緣内襯188可利用例如厚度〇15毫米之塑膠環 套以實施。而外侧導電封膠187則可由銀膠或銲錫組 成。 金屬外殼180除了可以保護振膜晶片12〇、金屬背 板140與電路板160上的訊號處理元件162外。同時， 可使金屬外殼18G以導電金屬材料製作，並接地，以 14 1312638 提供更好的電磁屏蔽效果，降低外界雜訊之干擾。 缠就二触實細㈣’ _微機電製程之限制與 振動效果之要求，振膜晶片m之厚度最好 至5微米之間。同時’金屬背板⑽之厚度 =係介於0.2至2毫米之間，駐極體材料層146之厚 介於0·5至25微米之間。此外’為了使振膜 =片120與金屬背板Η0維持適當之間隔，間隔層圖 ν、124之尽度最好係介於2至1〇〇微米之間，以使振 ，曰曰片120與金屬背板140所構成之平行板電容11〇 能對於振膜晶片120之振動有足夠之靈敏度。 凊參照第三Α與Β圖所示，係本發明振膜晶片12〇 之側視圆與底視圖。如圖所示，振膜122係形成於一 矽基板121之中央位置。此振膜122係可區分為一平 坦區122a與一皺折區i22b，其中，皺折區i22b係位 於平坦區122a之周圍’以提升振膜122受聲壓之變形 能力。一間隔層圖案124係位於此矽基板121之底面， 並且環繞於皺折區122b之外側。值得注意的是，如第 三B圖所示’雖然本實施例之振膜122係採方形設計， 而平坦區122a係呈圓形，但是並不限於此^如有需要， 振膜122亦可以採圓形或是矩形設計，而平坦區122a 與皺折區122b也可以採用不同之配置方式。 此外，請參照第三A圖所示，振膜122由下而上 15 1312638 依序包括一二氧化矽層Ll、一氮化矽層L2與一振膜 電極層L3。其中，二氧化石夕層L1與氮化石夕層L2係構 成此振膜122之本體。振膜電極層L3係由高導電係數 之金屬材料所構成，並且，此振膜電極層L3係與金屬 背板140構成平行板電容no之二個導電端。 请參照第四A與B圖所示’係本發明電容式麥克 風第一較佳實施例之俯視圖與剖面圖。相較於第一實 % 施例，本實施例省略了背板導電環（第二B圖標號 142)。如弟四B圖所不’振膜晶片120藉由内侧^_電 封膠189而固定於金屬外殼180之側壁184，藉由内侧 導電封膠189、侧壁184與外侧導電封膠187，則可使 得振膜晶片120與電路板160上之訊號處理元件162 電性連接。 至於金屬背板140,則是固定於振膜晶片120的下 側，如第四B圖所示，為了對組金屬背板14〇與振膜 鲁晶片120，因此本實施例係將隔離層圖案124製作成於 雙邊皆具有一缺口的構形，以利於振膜晶片12〇與金 屬背板140組成平行板電容110，其中，振膜晶片120 或金屬背板140的表面係設置有駐極體材料層，以形 成平行板電容110之一内建偏壓。 、實施上’可在第三A圖所示之振膜晶片120已完 成隔離層圖案124的製作之後，繼續在隔離層圖案124 16 1312638 ί約為10微米之PI或BCB等光阻材 M ^ ^人烤、曝光、顯影與硬烤的步驟，以定 於^如第四B圖所示之隔離圖案124實施例。而 ^本f施财_背婦電二B _號142)， ，.”、了電連金屬背板14G與電路6 背板刚與電路板_係另外製作有-導線ϋ ’平行板電容110因雜122 ★空氣振動而產1312638 month, a metal backplane, a circuit board and a metal casing, the diaphragm wafer and the backplane form a parallel plate capacitor, and the parallel plate capacitor uses an electret bias material in the electret material. Wherein, the diaphragm has a corresponding electrical signal' to process and output the electrical signal by the circuit board. The method for fabricating the electret capacitive type Shixi microphone provided by the present invention is to first fabricate a diaphragm wafer by using a microelectromechanical process. The manufacturing process of the diaphragm wafer comprises: (a) fabricating a layer of a diaphragm material on a surface of a substrate; (8) removing a portion of the 11th layer, revealing a surface below the layer of the diaphragm material, and (e) fabricating the vibrating electrode Layered on the surface of the diaphragm material layer; (d) a spacer layer pattern is formed on the chopped substrate. When the MEMS and the metal backing plate are respectively obtained by using the MEMS and the mechanical reinforced, respectively, the electret material must be formed in the manner of the diaphragm film or the metal surface. Board capacitors. And later, the recording circuit board and the metal core, sighed by the invention of the 1312638 electret condenser microphone. The development process of the present invention focuses on the improvement of the performance of the microphone, the process cost and the process steps. According to the present invention, an industrially competitive electret-capacitor microphone system is provided. The advantages and spirit of the present invention, as well as the more detailed embodiments, can be further illustrated by the following detailed description and the accompanying drawings. [Embodiment] Referring to Figures 2A and B, there is shown a plan view and a cross-sectional view of a first preferred embodiment of the electret condenser microphone of the present invention. As shown in the figure, the electret condenser dream microphone provided by the present invention has a parallel plate capacitor 110, a circuit board 160 and a metal casing 180. The parallel plate capacitor 110 includes a diaphragm wafer 12 and a metal back plate 140. Among them, the diaphragm wafer 120 is fabricated by a micro-electromechanical (MgMs) process, in which a diaphragm 122 is included. The metal backing plate 140 is fabricated by a mechanical process 'which is disposed at a predetermined distance below the diaphragm 122' to maintain the predetermined distance between the metal backing plate 140 and the diaphragm 122 through a spacer pattern 124. An electret material layer 146 is utilized to form a bias within the parallel plate capacitor 110, and an electret material layer 146 may be disposed on the lower surface of the diaphragm wafer 120 or the upper surface of the metal backplane 140. The metal casing 180 is used to mount and accommodate the parallel plate capacitors. As shown, the internal space of the metal casing 180 can be mainly divided into a front chamber s, an air layer, by the 11 1312638 parallel plate electric valley 110. Si and a rear chamber S2. The metal casing 丨 (8) has a venting path, mainly referring to the sound guiding hole 186 shown in Fig. 2B, so that the front chamber s can communicate with the outside air, so that the external sound pressure can vibrate the diaphragm 122. The circuit board 160 can be disposed under the metal back plate 14A and electrically connected to the parallel plate capacitor 11A. The parallel plate capacitor 110 can generate an electrical signal due to the vibration of the diaphragm 122 by the air. The circuit board 160 is used to amplify and output the electrical signal to other applications external to the electret condenser type X-ray microphone 100. The above is first to introduce the overall architecture of the present invention, and the following describes the metal backing plate 14 of the present invention fabricated by a machining process, the circuit board 160 and the metal casing 18〇, and the invention made by the microelectromechanical process. Diaphragm wafer 120. The metal back plate 140 has at least one opening M4 communicating with the air layer si and the rear chamber S2' to enhance the vibration effect of the diaphragm 122. In a preferred embodiment, the metal backsheet 140 preferably has an open cell ratio of between 5% and 30%. Further, as shown in the embodiment shown in Fig. 2B, the electret material layer 146 is disposed on the upper surface of the metal back plate 140, and may be provided by spin coating or press bonding. The electret layer material layer 146 may be composed of Teflon, ethylene propylene fluoride (FEP), polytetrafluoroethylene (PTFE) and oxidized dreams by corona charging (corona). The material layer 146 can be built in the required potential without the need for an applied current or voltage 'to generate a bias between the diaphragm wafer 120 and the metal back plate 140 (in this case, the diaphragm can be grounded 12 1312638) Moreover, according to this principle, an electret material layer (not shown) can be formed on the lower surface of the diaphragm lens 120 to build different potentials. The present invention relates to the metal back plate 140 and the electret material layer 146. A production example is provided as follows: a sheet of uncoated steel having a thickness of about 0.4 mm can be taken on the surface by hot pressing or spin coating with a layer of about 1.5 micron thick Teflon or 12 micron polytetrafluoroethylene (PTFE). The punching method is used to make the stainless steel plate have an opening ratio of 16% (to form the openings 144), and after corona charging, a permanent electret electret material can be formed on the surface of the stainless steel material. a stainless steel ring with a wall thickness of about 0.2 mm The height is cut into 1 mm to form a backplane conductive ring 142' shown in FIG. B. The metal backplane 140 and the circuit board 160' can be electrically connected and the space of the rear chamber S2 can be constructed. The circuit board 160 has at least A signal processing component 162 and a plurality of pins 164. The 'signal processing component 162 can be disposed on the upper surface of the circuit board 160 to amplify the electrical signal (current signal or voltage signal) from the backplane 140 and provide appropriate The impedance is matched. The pin 164 is located on the lower surface of the circuit board 160 and is electrically connected to the signal processing component 62 through at least one via (not shown) to output a signal. The detailed embodiment of a circuit board 160 of the present invention is The following is a description: The thickness of the circuit board 160 is 〇3 mm in one embodiment, and the upper surface portion § Η 说 says that the processing element 162 includes an ic or FET for signal amplification, and includes a capacitor or a resistor for filtering. , wave or adjust 13 Ϊ 312638 gain. One of the 1C or FET pins is connected to the backplane conductive ring 142, as a parallel plate capacitor 110 to generate an electrical signal input corresponding to the external sound signal. The other pin is connected to the metal side case 184 and the electrode of the diaphragm wafer 12 by an outer conductive seal 187 to form a complete metal shield to block external electromagnetic interference. The pin 164 on the lower surface of the circuit board 160 The metal board is composed of a metal chatter or a solder ball. The upper and lower sides of the circuit board 160 are electrically connected through the metal layers of the two sides, so that the electrical signal caused by the sound signal can be amplified by the IC or the FET and the resistor, and the pin 164 is used. The output is output to other applications outside the electret condenser microphone 100. The metal housing 180 includes an upper cover 182, a side wall 184, an insulating liner 188, and an outer conductive seal 187. The central position of the upper cover 182 has a sound guiding hole 186 for external sound pressure to pass through the sound guiding hole 186 to vibrate the diaphragm wafer 120. The side wall 184 is composed of a non-mineral metal sleeve having a wall thickness of 0.4 mm. The inner edge of the side wall 184 is provided with an insulating lining 188 to prevent the metal back plate 14 接触 from contacting the metal casing 18 ' 'insulating lining 188 It can be implemented using, for example, a plastic collar having a thickness of 15 mm. The outer conductive sealant 187 may be composed of silver glue or solder. The metal casing 180 can protect the diaphragm wafer 12, the metal back plate 140, and the signal processing component 162 on the circuit board 160. At the same time, the metal casing 18G can be made of a conductive metal material and grounded to provide better electromagnetic shielding effect with 14 1312638, and reduce the interference of external noise. The thickness of the diaphragm m is preferably between 5 μm and the requirement of the vibration and the effect of the vibrating effect of the two-touch thin (four)' _ micro-electromechanical process. At the same time, the thickness of the metal backing plate (10) is between 0.2 and 2 mm, and the thickness of the electret material layer 146 is between 0.5 and 25 microns. In addition, in order to maintain the proper interval between the diaphragm = sheet 120 and the metal back sheet , 0, the thickness of the spacer layers ν, 124 is preferably between 2 and 1 〇〇 micrometer to make the vibration, the cymbal 120 The parallel plate capacitor 11 formed with the metal back plate 140 can have sufficient sensitivity to the vibration of the diaphragm wafer 120. Referring to the third drawing and the drawing, a side view of the diaphragm wafer 12 of the present invention is shown in a side view and a bottom view. As shown, the diaphragm 122 is formed at a central position of a substrate 121. The diaphragm 122 can be divided into a flat area 122a and a crease area i22b, wherein the crease area i22b is located around the flat area 122a to enhance the deformation capability of the diaphragm 122 by sound pressure. A spacer layer pattern 124 is located on the bottom surface of the germanium substrate 121 and surrounds the outer side of the wrinkle region 122b. It should be noted that, as shown in FIG. 3B, although the diaphragm 122 of the embodiment has a square design and the flat area 122a is circular, it is not limited thereto. The diaphragm 122 can also be used if necessary. The circular or rectangular design is adopted, and the flat region 122a and the crease region 122b may also be configured differently. In addition, as shown in FIG. 3A, the diaphragm 122 sequentially includes a ruthenium dioxide layer L1, a tantalum nitride layer L2, and a diaphragm electrode layer L3 from bottom to top 15 1312638. Among them, the corrugated layer L1 and the nitride layer L2 form the body of the diaphragm 122. The diaphragm electrode layer L3 is composed of a metal material having a high conductivity, and the diaphragm electrode layer L3 and the metal back plate 140 constitute two conductive ends of the parallel plate capacitor no. Referring to Figures 4A and B, there are shown top and cross-sectional views of a first preferred embodiment of the capacitive microphone of the present invention. Compared to the first embodiment, the present embodiment omits the backplane conductive ring (second B icon number 142). As shown in FIG. 4B, the diaphragm wafer 120 is fixed to the side wall 184 of the metal casing 180 by the inner side sealant 189, and the inner conductive sealant 189, the side wall 184 and the outer conductive sealant 187 are The diaphragm wafer 120 can be electrically connected to the signal processing component 162 on the circuit board 160. As for the metal back plate 140, it is fixed on the lower side of the diaphragm wafer 120. As shown in FIG. 4B, in order to align the group metal back plate 14 with the diaphragm film 120, the present embodiment will be a spacer layer pattern. 124 is formed in a configuration having a notch on both sides, so that the diaphragm wafer 12 and the metal back plate 140 form a parallel plate capacitor 110, wherein the surface of the diaphragm wafer 120 or the metal back plate 140 is provided with an electret. The material layer is formed to form a bias voltage for one of the parallel plate capacitors 110. After the fabrication of the isolation layer pattern 124 has been completed in the diaphragm wafer 120 shown in FIG. 3A, the photoresist pattern M 4 such as PI or BCB in the isolation layer pattern 124 16 1312638 ί is about 10 μm. The steps of baking, exposing, developing, and hard-baking are performed in an embodiment of the isolation pattern 124 as shown in FIG. And ^本f施财_背妇电二B _号 142), ,.", the electrical metal back plate 14G and the circuit 6 back plate just with the circuit board _ series made with - wire ϋ 'parallel plate capacitor 110 Due to miscellaneous 122 ★ air vibration
=訊號可由電路板1⑼放大並輸出外部之其它應 用裝置。 以下，由第五A圖至第五1圖，並配合第二B圖， 以介紹本發，_體f容式轉克風_實施例製法流 ，。其中’帛五A圖至第五〇圖係關於以微機電製程 製作之振膜晶片12〇之製作流程。 凊參照第五A至(3圖。圖中係以振膜晶片一半的 剖面結構進行說明。首先，如第五A圖所示，在一矽 基板200上製作二氧化石夕圖案層21〇，此二氧化石夕圖案 層210具有複數個開口，定義振膜122上皺折之位置 (請同時參照第三A圖）’以作為製作皺折圖案之罩 幕。隨後，如第五B圖所示，利用反應式離子蝕剡 (Reactive Ion Etch，RIE)在矽基板2〇〇,之上表面形成 凹槽220 ’並除去殘留之二氧化矽圖案層21〇。接下來， 如第五C圖所示，利用熱氧化或是化學氣相沉積 (Chemical Vapor Deposition，CVD )全面形成二氧化矽 17 1312638 層=30於；δ夕基板2〇〇’上以作為振膜材料層。值得注意 的是，此二氧化矽層230係同時覆蓋凹槽22()之内表 面。隨後，如第五D，利用低壓化學氣相沉積（L〇wThe signal can be amplified by board 1 (9) and output to other external applications. Hereinafter, from the fifth A figure to the fifth one figure, and in conjunction with the second B picture, to introduce the present invention, the _ body f capacitive gram wind _ the embodiment method flow. Among them, 帛5A to 〇5 are related to the production process of the diaphragm wafer 12 manufactured by the microelectromechanical process. 5A to (3), the cross-sectional structure of the diaphragm wafer half is described. First, as shown in FIG. 5A, the SiO 2 pattern layer 21 is formed on a substrate 200, The dioxide pattern layer 210 has a plurality of openings defining the position of the wrinkles on the diaphragm 122 (please refer to FIG. 3A at the same time) as a mask for making the wrinkle pattern. Subsequently, as shown in FIG. It is shown that, by means of reactive ion etch (Reactive Ion Etch, RIE), a recess 220' is formed on the upper surface of the crucible substrate 2, and the residual ceria pattern layer 21 is removed. Next, as shown in the fifth C-picture As shown, the thermal oxidation or chemical vapor deposition (CVD) is used to form the ruthenium oxide 17 1312638 layer = 30 on the δ 夕 substrate 2 〇〇 ' as a diaphragm material layer. The ruthenium dioxide layer 230 simultaneously covers the inner surface of the recess 22 (). Subsequently, as in the fifth D, low pressure chemical vapor deposition (L〇w)
Pressure Chemical Vapor Deposition, LPCVD )或是電漿 辅助化學氣相沉積（Plasma_Enhaneed ehemiealPressure Chemical Vapor Deposition, LPCVD) or plasma-assisted chemical vapor deposition (Plasma_Enhaneed ehemieal)
Deposition，PECVD)全面沉積氮化石夕層240於石夕基板 200’上。同時’在矽基板2〇〇，之下表面製作一氮化石夕 圖案層241 ’以作為银刻去除石夕基板2〇〇,之罩幕。 接下來，如第五E圖所示，透過氮化石夕圖案241， 蝕刻去除裸露於外之矽基材，而形咸剩下環繞於振膜 晶片周圍之矽基板200”，以完全暴露二氧化矽層23〇 之下表面。隨後，如第五F圖所示，在氮化石夕層24〇 之上表面製作振膜電極圖案層250。振膜電極圖案層 250與第二B圖所示的金屬背板14〇共同形成平行板 電容110。接下來，如第五G圖所示，製作隔離層圖 案124於剩餘之石夕基板200“的上表面，並且環繞於皺 折區A之外圍，以完成此振膜晶片120之製作。最後， 則可在振膜晶片120的表面，利用旋轉塗佈或是壓合 的方式來設置一駐極體材料層，駐極體材料可選自鐵 氟Jl (Teflon)、乙烯丙烯氟化物（fep)、聚四氟乙烯 (PTFE )、二氧化石夕或其組合，並經電暈充電（c〇r〇na charge)而使其永久帶電。Deposition, PECVD) Fully deposits a layer of nitride layer 240 on the stone substrate 200'. At the same time, a nitriding layer pattern 241' is formed on the lower surface of the ruthenium substrate 2' to form a mask for the silver etched substrate. Next, as shown in FIG. E, through the nitride pattern 241, the bare substrate is removed by etching, and the salty substrate 200" surrounding the diaphragm wafer is left to completely expose the dioxide. The lower surface of the ruthenium layer 23 。. Subsequently, as shown in the fifth F diagram, the diaphragm electrode pattern layer 250 is formed on the surface of the nitriding layer 24 。. The diaphragm electrode pattern layer 250 and the second B diagram The metal back plates 14A collectively form a parallel plate capacitor 110. Next, as shown in the fifth G diagram, an isolation layer pattern 124 is formed on the upper surface of the remaining slab substrate 200" and surrounds the periphery of the crease area A, To complete the fabrication of the diaphragm wafer 120. Finally, an electret material layer may be disposed on the surface of the diaphragm wafer 120 by spin coating or pressing. The electret material may be selected from the group consisting of iron fluoride J1 (Teflon) and ethylene propylene fluoride ( Fep), polytetrafluoroethylene (PTFE), silica dioxide or a combination thereof, and is permanently charged by corona charging (c〇r〇na charge).
當振膜晶片120已製作完成（第五a圖至第五G 1312638 圖）’隨後的本發明步驟則完全脫離習知微機電製程以 製作駐極體電谷式石夕麥風的方法’而將以微機電製程 製作之振膜晶片與由機械加工製程製作之金屬背板 140、電路板160與金屬外殼18〇進行後段組装與封裝 的步驟，請繼續依序參照第五Η圖、第五〖圖^及第 二Β圖。 % 如第五Η ®所不’係將第五G圖步驟所得到的振 膜晶片120倒置，並放置於金屬背板M〇上，進而將 二者組合而成平行板電容携。值得一提的是，無論是 設置在金屬背板U0上表面的駐極禮材料層或是設置 在振膜晶片120下表面的駐極體材料層，都必需在將 振膜晶片12G與金屬背板⑽進行對組之前已設置完 成。如第五Η圖所示，隔離層圖案124係夹合於背板 140與振膜晶片120之間，以使背板14〇與振膜122間 樹圭地，由於本發明所提供之振膜晶 的材料皆耐高溫，因此，在對植金屬背 板，振，請時，可利用贿(== 術)的方式，在攝氏250度的環 例，溫度與時間可;著程序（此為其中一實施 裝置^极圖所示，在金屬背板140之下表面 ^上之金屬北^ 142 ’並將此背板導電環142連同位 ”、金屬月板140與振膜晶月120, 一併設置於電 19 1312638 路板160上。藉此’電路板16〇係得以電連至金屬背 板140,以接收來自金屬背板14〇之電流或電壓信號。 隨後，則可回到第二B圖，裝置金屬外殼180於 電路板160上’此金屬外殼180係套合於背板140與 振膜晶片120之外圍，完成本發明駐極體石夕麥克風1〇〇 之製作，並可以提供電磁屏蔽之效果。When the diaphragm wafer 120 has been completed (figure a to fifth G 1312638), the subsequent steps of the present invention are completely detached from the conventional microelectromechanical process to produce an electret electric valley type Shiyima wind. The steps of assembling and encapsulating the diaphragm wafer made by the microelectromechanical process with the metal back plate 140, the circuit board 160 and the metal casing 18 manufactured by the machining process, please continue to refer to the fifth figure and the Five 〖Figure ^ and the second map. %, for example, the fifth wafer is not inverted, and the diaphragm wafer 120 obtained in the fifth G step is inverted and placed on the metal back plate M, and then the two are combined to form a parallel plate capacitor. It is worth mentioning that whether the layer of the standing material placed on the upper surface of the metal back plate U0 or the layer of the electret material disposed on the lower surface of the diaphragm wafer 120 is required to be on the back of the diaphragm wafer 12G and the metal The board (10) is set to complete before the group is set. As shown in the fifth figure, the isolation layer pattern 124 is sandwiched between the back plate 140 and the diaphragm wafer 120, so that the back plate 14 is separated from the diaphragm 122, due to the diaphragm provided by the present invention. The crystal material is resistant to high temperature. Therefore, in the case of the metal backing plate, the vibration can be used. The method of bribe (== surgery) can be used in the case of 250 degrees Celsius, the temperature and time can be used; One of the implementation devices is shown in the pole figure, the metal north 142 ' on the lower surface of the metal back plate 140 and the back plate conductive ring 142 together with the bit", the metal moon plate 140 and the diaphragm film 120, one And disposed on the circuit board 130 160. The circuit board 16 is electrically connected to the metal back plate 140 to receive a current or voltage signal from the metal back plate 14 随后. Subsequently, it can be returned to the second In the figure B, the device metal casing 180 is mounted on the circuit board 160. The metal casing 180 is sleeved on the periphery of the back plate 140 and the diaphragm wafer 120 to complete the fabrication of the electret magnet microphone of the present invention. The effect of electromagnetic shielding.
相較於習知技術’本發明所提供之駐極體電容式 石夕麥克風係细職電技齡謂作麵以，因此， 高精度之振賴提供了極高的聲錢測敏感度 ;除此 ^夕’因振膜晶片可耐高溫，因此具有可利用SMT技 術進行組裝的伽。其它部份的元件—金屬背板、電 路板與金屬外殼射细機械加工餘以製備，不但 J降，製程成本，並且可使得組裝完成的駐極體電容Compared with the prior art, the electret capacitor type Shixi microphone provided by the present invention is used for the purpose of the technique, so that the high-precision excitation provides extremely high sensitivity of sound and sound; Since this diaphragm film can withstand high temperatures, it has a gamma that can be assembled using SMT technology. Other parts—metal backplanes, circuit boards, and metal casings are finely machined to prepare, not only J drop, process cost, but also the assembled electret capacitors.
:了麥克風具有較習知技術優良的屏蔽效果，可大幅 減>、電磁干擾，而降低雜訊的比率。 非二2述係，佳實施例詳細說明本發明，而 、|本發明之範圍，而且熟知此 瞭，適當而作些微•變及調整，仍將=明 要義所在，亦不脫離本發明之精神和範圍。，之 【圖式簡單說明】 20 1312638 第_ =圖_示電容式麥克風之運作原理。 第二A —傳統電容式麥克風之結構。 佳圖係本發明駐極體電容切麥克風第-較 二圭實施例之俯圖與剖面圖。 曰A f B囷係本發明利用微機電技術所製作之振膜 ^曰一較佳實施例之剖面圖與底視圖。 =與B _本發明駐極體電容切麥克風第二較 /圭實施例之俯視圖與剖面圖。: The microphone has a better shielding effect than the conventional technology, which can greatly reduce > electromagnetic interference and reduce the ratio of noise. The present invention is described in detail, and the scope of the present invention is well known, and appropriate modifications and adjustments will still be made without departing from the spirit of the present invention. And scope. [Simplified description of the diagram] 20 1312638 The first _ = diagram _ shows the operation principle of the condenser microphone. Second A—The structure of a conventional condenser microphone. The picture is a top view and a cross-sectional view of the electret condenser-cut microphone of the present invention.曰A f B囷 is a cross-sectional view and a bottom view of a preferred embodiment of the present invention using microelectromechanical technology. = and B - The top view and cross-sectional view of the second embodiment of the electret condenser-cut microphone of the present invention.
卓A至I圖係顯示本發明駐極體電容式石夕麥克風之勢 作方法一較佳實施例。 、 【主要元件符號說明】 振膜1〇，122 背板12 開孔14, 144 電容式麥克風100 平行板電容110 振膜晶片120 砍基板 121,200,200，,200” 平坦區122a 皺折區122b 間隔層圖案124 _金屬背板140 背板導電環142 導線143 駐極體材料層146 電路板160 訊號處理元件162 接腳164 金屬外殼180 上蓋182 側壁184 導音孔186 外側導電封膠187 1 *- 21 1312638 絕緣内襯188 内側導電封膠189 二氧化矽圖案層210 皺折220 二氧化矽層230 氮化矽層240 振膜電極圖案層250 氮化矽圖案層241 % 22The diagrams of the A to I diagrams show the preferred embodiment of the method of the electret condenser type magnetic microphone of the present invention. [Major component symbol description] Diaphragm 1〇, 122 Back plate 12 Opening 14, 144 Capacitive microphone 100 Parallel plate capacitor 110 Diaphragm wafer 120 Cut substrate 121, 200, 200, 200" Flat area 122a Wrinkle area 122b Spacer pattern 124 _ metal back plate 140 back plate conductive ring 142 wire 143 electret material layer 146 circuit board 160 signal processing element 162 pin 164 metal case 180 upper cover 182 side wall 184 sound hole 186 outer conductive sealant 187 1 *- 21 1312638 Insulation lining 188 inner conductive sealant 189 ruthenium dioxide pattern layer 210 wrinkle 220 ruthenium dioxide layer 230 tantalum nitride layer 240 diaphragm electrode pattern layer 250 tantalum nitride pattern layer 241 % 22