201108755 六、發明說明： ， 【發明所屬之技術領域】 [0001] 本發明涉及一種熱致發聲裝置及其製備方法，尤其涉及 一種基於金屬材料之熱致發聲裝置及其製備方法。 【先前技術·】 [0002] 發聲裝置一般由訊號輸入裝置和發聲元件組成，通過訊號 輸入裝置輸入訊號到該發聲元件，進而發出聲音。熱致 發聲裝置為發聲裝置中之一種，其為基於熱聲效應原理 之一種發聲裝置，先前技術中之熱致發聲裝置為採用熱 _ 〇 容較低之金屬材料作為發聲元件。 [0003] H. D. Arnold和 I. B. Crandal 1 在文獻 “The thermophone as a precision source of sound” ，201108755 VI. Description of the Invention: [Technical Field] [0001] The present invention relates to a thermo-acoustic sounding device and a method of fabricating the same, and more particularly to a metal-based thermal sound generating device and a method of fabricating the same. [Prior Art·] [0002] A sounding device generally consists of a signal input device and a sounding element, and a signal is input through the signal input device to the sounding element to emit a sound. The thermo-acoustic device is one of the sound-emitting devices, which is a sound-generating device based on the principle of thermoacoustic effect, and the thermo-acoustic device in the prior art uses a metal material having a lower heat capacity as a sound-emitting element. [0003] H. D. Arnold and I. B. Crandal 1 in the literature "The thermophone as a precision source of sound",
Phys. Rev. 10, p22-38 (1917)中揭示一種簡單之熱 致發聲裝置，其包括一作為發聲元件之鉑片、設置於該 鉑片兩端且用於夾持該鉑片使其懸空設置之夾具及與該 鉑片電連接之訊號輸入裝置。該熱致發聲裝置通過向該A simple thermoacoustic device is disclosed in Phys. Rev. 10, p22-38 (1917), which comprises a platinum sheet as a sounding element, disposed at both ends of the platinum sheet and used to hold the platinum sheet to be suspended. A fixture for setting and a signal input device electrically connected to the platinum sheet. The thermo-acoustic device passes the
鉑片中通入交流電來實現發聲。該鉑片具有較薄之厚度 (J ，其厚度值為0. 7微米，從而使該鉑片具有較小之單位面 積熱容（heat capacity per area)，故，當交流電 通過該銘片時，其内部產生之熱量通過熱交換之方式迅 速傳導給周圍空氣，從而促使周圍空氣分子運動並發出 聲波。 [0004] 然而，先前熱致發聲裝置中，由於受金屬製備工藝之限 制，形成可懸空設置且具有更小厚度之金屬片難度較大 ，故導致金屬片之單位面積熱容值無法達到很小，進而 098127914 表單編號A0101 第4頁/共23頁 0982047886-0 201108755 [0005] [0006] Ο [0007] Ο [0008] 098127914 使先前熱致發聲裝置之發聲強度較低，限制了其在實際 中之應用。 【發明内容】 有鑒於此，提供一種具有較高發聲強度之熱致發聲裝置 及其製備方法實為必要。 一種熱致發聲裝置，其包括：一訊號輸入裝置；及一發 聲元件，該發聲元件包括一金屬膜，且該金屬膜與所述 訊號輸入裝置電連接；其中，該發聲元件進一步包括一 基體及設置於該基體之複數微結構，所述金屬膜設置於 所述複數微結構上並通過該複數微結構支撐，且該金屬 膜相對於所述基體懸空設置，所述訊號輸入裝置輸入電 訊號給該金屬膜，並通過該金屬膜加熱周圍氣體介質發 出聲波。 一種熱致發聲裝置之製備方法，其包括以下步驟：提供 一基體，該基體具有一表面；在所述基體之表面形成複 數微結構；在該基體之表面形成一犧牲層，以填充所述 複數微結構之間之間隙；在所述犧牲層之表面形成一金 屬膜；加熱所述犧牲層，直至所述犧牲層完全分解，從 而形成一發聲元件；提供一訊號輸入裝置，使該訊號輸 入裝置與所述金屬膜電連接，從而形成一熱致發聲裝置 Ο 相較於先前技術，由於所述熱致發聲裝置中，所述金屬 膜通過所述複數微結構與所述基體表面懸空設置，從而 使該金屬膜與周圍空氣或其他氣體介質可進行充分之熱 交換；同時，採用本發明之製備方法可製備獲得具有較 表單編號Α0101 第5頁/共23頁 0982047886-0 201108755 小厚度、較小單位面積熱容之金屬膜，故，本發明之熱 致發聲裝置具有較高之發聲強度。 【實施方式】 [0009] 以下將結合附圖詳細說明本發明實施例之熱致發聲裝置 及其製備方法。 [0010] 請參閱圖1，本發明第一實施例提供一種熱致發聲裝置10 ，該熱致發聲裝置10包括一訊號輸入裝置12、一發聲元 件14及至少兩個電極18。 [0011] 所述發聲元件14包括一基體16、複數微結構17及一金屬 膜15，所述基體16具有一表面162，所述微結構17設置 於該基體16之表面162，所述金屬膜15設置於該複數微結 構17上，且通過該複數微結構17與所述基體16之表面 162懸空設置。所述至少兩個電極18間隔設置且與所述金 屬膜15電連接。所述至少兩個電極18分別通過外接導線 19與所述訊號輸入裝置12之兩端電連接，用於將所述訊 號輸入裝置12中之電訊號輸入到所述發聲元件14中。 [0012] 所述基體16主要起支撐所述微結構17及所述金屬膜15之 作用，其形狀不限，任何具有確定形狀之物體均可作為 本實施例中之基體16。本實施例中，所述複數微結構17 為所述基體16本身所具有之複數微小凸起，所述金屬膜 15直接設置於該複數凸起，且通過該複數凸起與所述基 體16之表面162懸空設置。該基體16之材料不限，本實施 例中，該基體16之材料為一硬性或柔性之絕緣材料，如 金剛石、玻璃、石英塑膠或樹脂等，優選地，該基體16 之材料應具有較好之絕熱性能，從而防止該金屬膜15產 098127914 表單編號A0101 第6頁/共23頁 0982 201108755 生之熱量過度被該基體16吸收，故無法達到加熱周圍氣 體介質進而發聲之目的。 [0013] Ο 所述金屬膜15與每個微結構17之接觸面積應小於1平方微 米，以使該金屬膜15盡可能與周圍空氣或其他外界氣體 或液體介質具有較大之接觸面積，並具有盡可能大之散 熱面積，進而可在一定程度上改善所述發聲裝置10之發 聲效果。同時，所述微結構17與所述金屬膜15之相鄰之 兩個接觸位置之間之最短距離應小於1微米，以確保所述 金屬膜15均勻地被所述微結構17支撐，且不會在重力之 作用下發生變形。由於該金屬膜15通過基體16及微結構 17支撐，故該金屬膜15可承受強度較高之訊號輸入而不 致發生變形，從而具有較高之發聲強度。 [0014] 〇 所述金屬膜15之材料為低熱容或具有良好延展性之材料 ，可為鐵、錄、鈷、銘、銅、銀、金、，把、銘、鈹、銅 或鉛。由於該金屬膜15通過上述基體16及複數微結構17 支撐，故該金屬膜15之厚度可極薄且在工作過程中不易 發生變形，本實施例中該金屬膜15之厚度可小於0. 7微米 。同時，由於單位面積之熱容除與材料本身之種類有關 外，還與該材料之厚度有關，即相同材料形成之金屬膜 15，其厚度越大，單位面積熱容越大，厚度越小，單位 面積熱容越小，故，本實施例中，具有較小厚度之金屬 膜15之單位面積熱容較小，其單位面積熱容可小於2χ10_ 4焦耳每平方厘米開爾文。所述金屬膜15之發聲頻率與其 單位面積熱容密切相關，即金屬膜15之單位面積熱容愈 大，則發聲頻率範圍愈窄，且發聲強度愈低；反之，單 098127914 表單編號Α0101 第7頁/共23頁 0982047886-0 201108755 位面積熱容愈小，則發聲頻率範圍愈寬，且發聲強度愈 高。可見，本實施例發聲裝置10中採用具有較小厚度金 屬膜15之發聲元件14具有較寬之發聲頻率範圍及較高之 發聲強度。 [0015] [0016] 所述至少兩個電極18由導電材料形成，其具體形狀結構 不限。具體地，所述至少兩個電極18可選擇為層狀、棒 狀、塊狀或其他形狀。所述至少兩個電極18之材料可選 擇為金屬、導電膠、金屬性奈米碳管、銦錫氧化物（IT〇 )等。本實施例中，所述電極18為兩個棒狀金屬電極， 所述電極1 8用於實現所述詆號輸入裝置12輿所述發聲元 件14之間之電連接。所述電極18間隔設置固定在所述金 屬膜15之表面，具體為，該至少兩個電極18可通過導電 枯膠固定於所述金屬膜15並實現電連接’該導電粘膠可 為銀膠。優選之，本實施例中電極18之長度等於金屬膜 15之寬度’從而使音頻電訊號傳導至整個金屬膜15中。 另’所述至少兩個電極18為熱致發聲豉置10之可選元件 ’由於所述金屬膜15導電，故，所述訊號輸入裝置12也 可與所述金屬膜直接電連接，進而將音頻電訊號直接輸 入所述發聲元件14。 所述訊號輸入裝置12可直接通過導線或電極引線等方式 與所述金屬膜15電連接，或者間接地通過電極18與所述 金屬膜15電連接。只需確保所述訊號輸入裝置12能將電 訊號輸入給所述金屬膜15即可。任何可實現所述訊號輸 入裝置12與所述金屬膜15之間電連接之方式都在本發明 之保護範圍之内。 098127914 表單煸號Α0101 第8頁/共23頁 0982047886-0 201108755 [〇〇17]所述訊號輸入裝置12輸入之訊號包括音頻電訊號等。所 述訊號輸入裝置12通過導線19與所述電極18電連接，並 通過所述電極18將訊號輸入到所述發聲元件14中。 [〇〇18]上述發聲裝置1〇在使用時，由於所述金屬膜15具有較小 之厚度、較小之熱容及較大之散熱表面，在輸入訊號後 ’該金屬膜15可迅速升降溫，產生週期性之溫度變化， 並和周圍氣體介質快速進行熱交換，使周圍氣體介質迅 速膨脹和收縮，進而發出人耳可感知之聲音，且所發出 Q 之聲音頻率範圍較寬，可達到20赫蘇至10萬赫茲，發聲 強度可超過60分貝每瓦聲麇級，且發聲效果較好。故本 實施例中，所述發聲裝置丨〇具有廣泛之應用範圍。另， 本實施例中之金屬膜丨5由於受基體16及複數微結構17之 支擇’故不容易發生變形或者損壞，且可承受較高強度 之訊號輸入，使用壽命較長。 [0019]請參閱圖2，本發明提供一雜上述第一實施例發聲装置之 製備方法，其具體包括以下步驟： ◎ [〇〇2〇] 步驟一 ’提供一基體，該纂體具有一表面； [0021] 步驟二’在所述基體之表面形成複數微結構； [0022] 該步驟具體為，通過刻蚀工藝在上述基底之表面刻餘出 複數微小凸起以形成複數橄結構’如光刻蝕、電子束刻 蝕或離子束刻蝕等。 [0023] 步驟三，在該基體之表面形成一犧牲層，以填充該複數 微結構之間之間隙； 098127914 表單編號A0101 第·9頁/共23頁 0982047886-0 201108755 [0024] 所述犧牲層之材料為具有較低分解溫度之有機材料，且 該分解溫度需低於上述基體及所述發聲裝置中金屬膜之 熔點，優選為可在450°C以下完全分解之有機材料，如丙 烯酸樹脂或硝棉。本實施例為丙烯酸樹脂。該犧牲層之 厚度不限。 [0025] 該犧牲層之製備方法具體包括：首先，提供一有機聚合 物溶液，該有機聚合物溶液由按照一定比例配比之聚合 物、增塑劑、溶劑及助溶劑組成。所述聚合物包括聚甲 基丙烯酸異丁酯和丙烯酸B-72樹脂，所述增塑劑可為鄰 苯二甲酸二丁酯，所述溶劑包括醋酸乙酯和醋酸丁酯， 所述助溶劑包括無水乙醇和正丁醇，本實施例中該聚合 物溶液之具體配比如表1所示；其次，將所述聚合物溶液 通過人工塗敷法或旋轉塗敷法均勻塗敷於所述基體之表 面並使其靜置一段時間，從而形成一犧牲層。此外，該 製備方法中為減小固體之表面張力，有利於聚合物溶液 在所述具體表面上擴散鋪展，或使不平整之基體可具有 一個平滑之表面，可進一步在塗敷所述聚合物溶液之前 採用水或水之溶液潤濕基體1分鐘~10分鐘。 [0026] 表1聚合物溶液組分配比 主要成分 化學物質 用量 本實施例 聚合物 聚甲基丙烯酸 2克〜8克 6克 異丁酯 聚合物 丙烯酸B-72 0. 03克〜0. 07 0. 07克 樹脂 克 增塑劑 鄰苯二甲酸二 0. 5毫升〜4毫 1毫升 表單編號A0101 第10頁/共23頁 0982047886-0 098127914 201108755 丁酯 升 溶劑 醋酸乙酯 50毫升〜64毫 64毫升 升 溶劑 醋酸丁酯 15毫升〜30毫 21毫升 升 助溶劑 無水乙醇 1毫升〜3毫升 1毫升 助溶劑 正丁醇 1宅升〜3宅升 1毫升 步驟四，在所述犧牲層之表面形成一金屬膜； [0028] 所述金屬膜之材料為具有低熱容或延展性好之金屬材料 ，如鐵、鎳、钻、銀、銅、金、妃、銘、鈹、銦、銘或 鉛，該金屬膜之具體製備方法為物理氣相沈積法如真空 蒸鍍法或磁控濺射法等。通過該方法可在犧牲層表面形 成一厚度較小之金屬膜，且可使所述金屬膜不致直接形 成在所述基體上並與該基體結合為一體。 [0029] 步驟五，加熱所述犧牲層，直至該犧牲層完全分解，從 而形成所述發聲元件； [0030] 加熱上述在基體與金屬膜之間之犧牲層，直到該犧牲層 完全分解，在該犧牲層分解之過程中，隨著該犧牲層厚 度之變薄，形成在該犧牲層表面之金屬膜便在重力之作 用下逐漸下降，從而使得所述金屬膜與所述基體之微結 構接觸。由於所述犧牲層之分解溫度均低於所述金屬膜 和基體之熔點，故，當犧牲層完全分解之後，所述金屬 膜與所述基體均不會熔融，且不會由於熔融而發生彼此 結合之現象。故，將犧牲層去除之後，所述金屬膜與所 述基體之表面將會通過所述複數微結構懸空設置，使得 098127914 表單編號A0101 第11頁/共23頁 0982047886-0 201108755 金屬膜與空氣或其料界It體或液體介 質具有更大之接 觸面積。 [0031] [0032] [0033] [0034] 進〆步也該步驟還包括提供至少兩個電極通過導電 枯膠將4兩個電極枯結並間隔固定在所述發聲 元件即金 廣麟之表面。 少鱗’ *供°凡號輪入裝置，使該訊號輸入裝置與所 述發聲元件電連接’從而形成_熱致發聲裝置。 該少驟中所述訊號輪人裝置可為Mp3、收音機等音頻輸 入装置或者功率玫梦等，其可通過轉線直接將該訊 號輸入裝置與料金屬《連接，或者遍地將該訊號 输八裝置通過至少兩個電極與所述金>8膜實現電連接， 該訊號輸人装置與電極之間通過導線相連接。 本實施ϋ巾所述製備方法通過在所述基體之表面形成 複^：H再形成—犧牲層以填充所述複數微結構之 間之間隙it在該犧牲層之表面沈積具有較薄厚度之金 屬膜’之後再採用加熱之方輕該犧牲層去除 ，從而獲 得所述發聲元件。可見，整個過程中 ，只需通過加熱之 方义將所述犧牲層去掉即可使所述金屬膜 自支撐地通過 所述複數微結構與所述基體之表面部分懸空設置，所謂 自支撐係指無需通過一支撐體支撐，也可保持自身特定 之形狀而不發生破壞。即，該金屬膜部分受所述複數微 結構支撐，部分自支撐地懸空設置，且該部分懸空設置 之金屬膜可原位形成，所謂原位形成係指該金屬膜在實 現懸空設置之過程中與所述基底和複數微結構之相對位 098127914 表單編號A0101 第12頁/共23頁 0982047886-0 201108755 ❹ [0035] [0036] Ο 移較小，其相對位置近_定。故該形成過程不容易使 該具有較祕叙金屬__述基絲複減結構之 相對位置發生變動而發生損壞’且也可同時實現使該金 属膜懸空設置。可見，本發明之製備方法可使具有較薄 厚度之金屬膜通過複數微結構切而部分懸空設置。而 相同材料之金屬膜，厚度較小之金屬膜比厚度較大之金 廣膜單位面積熱容小，發聲頻率範園寬，發聲強度高。 所述複數微結構為該金輕提供魏切，使該發聲裝 置在使用之過程中不易破壞’同時’該基體表面與該金 屬膜之間懸空設置’從而保證該金屬骐具有盡可能大之 散熱面積，並具有理想之發聲效果β 請參閱圖3，本發明第二實施例提供—種熱致發聲裝置2〇 ，包括一訊號輸入裝置22、一發聲元件24及至少兩個電 極2 8 〇 所述發聲元件24包括一基體26、複數微結構27及一金屬 膜25 ’所述基體26具有一表面262 ’所述微結構27設置 於該基體26之表面262 ’所述金屬膜25設置於該複數微結 構27上，且通過該複數微結構27與所述基體26释空設置 。所述至少兩個電極28間隔設置且與所述金屬膜μ電連 接。所述至少兩個電極28分別通過外接導線29與所述訊 號輸入裝置22之兩端電連接，用於將所述訊號輸入裝置 22中之電訊號輸入到所述發聲元件24中。 本實施例與上述第一實施例之熱致發聲裝置1〇之結構基 本相同，其區別在於’本實施例之微結構27為顆粒，所 述金屬膜25設置於該複數顆粒上。 098127914 表單編號Α0101 第13頁/共23頁 0982047886-0 [0037] 201108755 [0038] 所述顆粒均勻分散於所述基體26之表面262，所述顆粒直 徑小於1微米。該顆粒之材料不限，可為一硬性材料，如 金剛石、玻璃或石英。優選地，該複數顆粒之材料應具 有較好之絕熱性能，從而防止該金屬膜25產生之熱量過 度之被該複數顆粒吸收，無法達到加熱周圍氣體介質進 而發聲之目的。進一步地，所述基體26之表面262可設置 有一粘膠層，用於粘結並固定所述複數顆粒。該粘膠層 所選用之粘膠種類不限，只需確保將本實施例中之複數 顆粒均勻固定於所述基體26之表面262即可。 [0039] 請參閱圖4，本發明提供一種上述第二實施例發聲裝置之 製備方法，其具體包括以下步驟： [0040] 步驟一，提供一基體，該基體具有一表面； [0041] 步驟二，在所述基體之表面形成複數微結構； [0042] 步驟三，在該基體之表面形成一犧牲層，以填充該複數 微結構之間之間隙； [0043] 步驟四，在所述犧牲層之表面形成一金屬膜； [0044] 步驟五，加熱所述犧牲層，直至該犧牲層完全分解，從 而形成所述發聲元件； [0045] 步驟六，提供一訊號輸入裝置，使該訊號輸入裝置與所 述發聲元件電連接，從而形成一熱致發聲裝置。 [0046] 本實施例發聲裝置之製備方法與上述第一實施例發聲裝 置之製備方法基本相同，其區別在於，本實施例發聲裝 置製備方法之步驟二所形成之複數微結構為顆粒。具體 098127914 表單編號A0101 第14頁/共23頁 0982047886-0 201108755 為：首先，在所述基體之表面塗覆一粘膠層；其次，提 供複數顆粒，將所述複數顆粒均勻地分散在所述粘膠層 之表面，使得該複數顆粒固定於所述基體之表面，從而 形成複數微結構。 [0047] Ο ❾ [0048] 本發明實施例提供之熱致發聲裝置及其製備方法具有以 下優點：由於所述熱致發聲裝置中之金屬膜通過基體及 複數微結構支撐，故該金屬膜之厚度即使很小仍可承受 強度較高之訊號輸入而不致發生變形，從而具有較高之 發聲強度；通過本發明製備方法製備之金屬膜，其厚度 可小於0.7微米’而厚度越小，其單位面積熱容越小，本 發明之單位面备熱容可小於2x1 〇_4焦耳每平方厘米開爾 文，而金屬膜之發聲頻率與其單位面積熱容密切相關， 單位面積熱容愈小，發聲頻率範圍愈寬，聲波強度愈高 ，故本發明發聲裝置之發聲頻率範圍較寬，發聲強度較 1¾ ;本發明之製備方法可使所製備之金屬联與所述基體 表面懸空設置，使金屬膜與周圍介質之接觸面積較大， 工作時，該金屬膜可與周圍之介質迅速地進行熱交換並 使周圍介質迅速膨脹和收縮，進而發出人耳可感知之聲 音。 綜上所述，本發明確已符合發明專利之要件，遂依法提 出專利申請。惟，以上所述者僅為本發明之較佳實施方 式’自不能以此限制本案之申请專利範圍。舉凡熟步本 案技藝之人士援依本發明之精神所作之等效修飾或變化 ，皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 098127914 表單編號Α0101 第15頁/共23頁 0982047886-0 201108755 [0049] [0050] [0051] [0052] 圖1為本發明第一實施例熱致發聲裝置之結構示意圖。 圖2為本發明第一實施例熱致發聲裝置製備方法流程圖。 圖3為本發明第二實施例熱致發聲裝置之結構示意圖。 【主要元件符號說明】 熱致發聲裝置 10，20 訊號輸入裝置 12，22 發聲元件 14，24 金屬膜 15，25 基體 16，26 表面 162 ， 262 微結構 17，27 電極 18，28 導線 19，29 098127914 表單編號A0101 第16頁/共23頁 0982047886-0An alternating current is applied to the platinum sheet to achieve sound generation. The platinum sheet has a relatively thin thickness (J, and has a thickness value of 0.7 μm, so that the platinum sheet has a small heat capacity per area, so when alternating current passes through the crystal sheet, The heat generated inside is rapidly transmitted to the surrounding air by heat exchange, thereby causing the surrounding air molecules to move and emit sound waves. [0004] However, in the prior thermal sounding device, due to the limitation of the metal preparation process, a dangling setting is formed. Moreover, it is difficult to have a metal sheet having a smaller thickness, so that the heat capacity per unit area of the metal piece cannot be made small, and further 098127914 Form No. A0101 Page 4 / Total 23 Page 0992047886-0 201108755 [0005] [0006] [0007] 098127914 makes the sound intensity of the previous thermo-acoustic device lower, which limits its application in practice. [Invention] In view of the above, a thermo-acoustic device with higher vocal intensity is provided. The preparation method is really necessary. A thermo-acoustic device comprising: a signal input device; and a sounding element, the sounding element comprising a metal film, and The metal film is electrically connected to the signal input device; wherein the sounding element further comprises a substrate and a plurality of microstructures disposed on the substrate, the metal film being disposed on the plurality of microstructures and supported by the plurality of microstructures And the metal film is suspended relative to the substrate, the signal input device inputs a signal to the metal film, and the surrounding gas medium is heated by the metal film to emit sound waves. A method for preparing a thermal sound generating device, comprising the following steps Providing a substrate having a surface; forming a plurality of microstructures on a surface of the substrate; forming a sacrificial layer on a surface of the substrate to fill a gap between the plurality of microstructures; Forming a metal film on the surface; heating the sacrificial layer until the sacrificial layer is completely decomposed to form a sound emitting element; providing a signal input device to electrically connect the signal input device to the metal film to form a thermal Sounding device Ο compared to the prior art, in the thermal sound generating device, the metal film passes the The plurality of microstructures are suspended from the surface of the substrate, so that the metal film can be sufficiently exchanged with the surrounding air or other gaseous medium; and at the same time, the preparation method of the present invention can be used to obtain a form number Α0101, page 5 / A total of 23 pages 0982047886-0 201108755 small thickness, small unit area heat capacity metal film, therefore, the thermal sound generating device of the present invention has a high sound intensity. [Embodiment] [0009] The following will be described in detail with reference to the accompanying drawings A thermo-acoustic device according to an embodiment of the present invention and a method for fabricating the same. [0010] Referring to FIG. 1, a first embodiment of the present invention provides a thermo-acoustic device 10, which includes a signal input device 12, The sounding element 14 and at least two electrodes 18. [0011] The sounding element 14 includes a substrate 16, a plurality of microstructures 17, and a metal film 15, the substrate 16 has a surface 162, and the microstructures 17 are disposed on the surface 162 of the substrate 16, the metal film 15 is disposed on the plurality of microstructures 17, and is disposed by the plurality of microstructures 17 and the surface 162 of the substrate 16 being suspended. The at least two electrodes 18 are spaced apart and electrically connected to the metal film 15. The at least two electrodes 18 are electrically connected to the two ends of the signal input device 12 via external wires 19 for inputting electrical signals in the signal input device 12 into the sound emitting element 14. [0012] The substrate 16 mainly functions to support the microstructures 17 and the metal film 15, and its shape is not limited. Any object having a certain shape can be used as the substrate 16 in this embodiment. In this embodiment, the plurality of microstructures 17 are a plurality of micro protrusions of the substrate 16 itself, and the metal film 15 is directly disposed on the plurality of protrusions, and the plurality of protrusions and the substrate 16 are The surface 162 is suspended. The material of the substrate 16 is not limited. In this embodiment, the material of the substrate 16 is a rigid or flexible insulating material, such as diamond, glass, quartz plastic or resin. Preferably, the material of the substrate 16 should have better materials. The thermal insulation property prevents the metal film 15 from producing 098127914. Form No. A0101 Page 6 / Total 23 page 0892 201108755 The heat generated is excessively absorbed by the substrate 16, so that the heating of the surrounding gaseous medium cannot be achieved. [0013] 接触 the contact area of the metal film 15 with each of the microstructures 17 should be less than 1 square micrometer, so that the metal film 15 has a large contact area with ambient air or other external gas or liquid medium as much as possible, and The heat dissipation area is as large as possible, and the sounding effect of the sounding device 10 can be improved to some extent. Meanwhile, the shortest distance between the two contact positions of the microstructure 17 and the metal film 15 should be less than 1 micrometer to ensure that the metal film 15 is uniformly supported by the microstructure 17, and Will deform under the influence of gravity. Since the metal film 15 is supported by the substrate 16 and the microstructure 17, the metal film 15 can withstand high-intensity signal input without being deformed, thereby having a high vocal intensity. [0014] 材料 The material of the metal film 15 is a material having low heat capacity or good ductility, and may be iron, recorded, cobalt, inscription, copper, silver, gold, p, m, y, copper or lead. The thickness of the metal film 15 may be less than 0.7 in this embodiment, the thickness of the metal film 15 may be less than 0.7. Micron. At the same time, since the heat capacity per unit area is related to the type of the material itself, it is also related to the thickness of the material, that is, the metal film 15 formed of the same material, the larger the thickness, the larger the heat capacity per unit area, and the smaller the thickness. The smaller the heat capacity per unit area, the smaller the heat capacity per unit area of the metal film 15 having a smaller thickness, the smaller the heat capacity per unit area can be less than 2χ10_4 joules per square centimeter Kelvin. The sounding frequency of the metal film 15 is closely related to the heat capacity per unit area, that is, the larger the heat capacity per unit area of the metal film 15, the narrower the sounding frequency range and the lower the sounding intensity; otherwise, the single 098127914 form number Α0101 7th Page / Total 23 pages 0982047886-0 201108755 The smaller the heat capacity of the area, the wider the range of sound frequencies and the higher the sound intensity. It can be seen that the sound emitting element 14 having the metal film 15 having a small thickness in the sounding device 10 of the present embodiment has a wide sounding frequency range and a high sounding intensity. [0016] The at least two electrodes 18 are formed of a conductive material, and the specific shape structure thereof is not limited. In particular, the at least two electrodes 18 may be selected from layers, rods, blocks or other shapes. The material of the at least two electrodes 18 may be selected from the group consisting of a metal, a conductive paste, a metallic carbon nanotube, an indium tin oxide (IT〇), and the like. In this embodiment, the electrode 18 is two rod-shaped metal electrodes, and the electrode 18 is used to realize electrical connection between the nickname input device 12 and the utterance element 14. The electrode 18 is disposed on the surface of the metal film 15 at intervals. Specifically, the at least two electrodes 18 can be fixed to the metal film 15 by conductive glue and electrically connected. The conductive adhesive can be silver glue. . Preferably, the length of the electrode 18 in this embodiment is equal to the width of the metal film 15 so that the audio signal is conducted into the entire metal film 15. In addition, the at least two electrodes 18 are optional elements of the thermal squealing device 10. Since the metal film 15 is electrically conductive, the signal input device 12 can also be directly electrically connected to the metal film, thereby The audio signal is directly input to the sounding element 14. The signal input device 12 can be electrically connected to the metal film 15 directly through a wire or an electrode lead or the like, or can be electrically connected to the metal film 15 through the electrode 18. It is only necessary to ensure that the signal input device 12 can input a signal to the metal film 15. Any manner of achieving electrical connection between the signal input device 12 and the metal film 15 is within the scope of the present invention. 098127914 Form Α Α 0101 Page 8 of 23 0982047886-0 201108755 [〇〇17] The signal input by the signal input device 12 includes an audio signal and the like. The signal input device 12 is electrically connected to the electrode 18 via a wire 19, and a signal is input through the electrode 18 into the sounding element 14. [〇〇18] When the above-mentioned sounding device 1 is in use, since the metal film 15 has a small thickness, a small heat capacity and a large heat dissipation surface, the metal film 15 can be quickly raised and lowered after the input signal Temperature, producing periodic temperature changes, and rapid heat exchange with the surrounding gas medium, so that the surrounding gas medium rapidly expands and contracts, thereby emitting a sound that can be perceived by the human ear, and the sound frequency of the emitted Q is wide. From 20 hes to 100,000 Hz, the sound intensity can exceed 60 decibels per watt sonar level, and the sound effect is better. Therefore, in the embodiment, the sounding device has a wide range of applications. In addition, the metal film defect 5 in this embodiment is not easily deformed or damaged due to the selection of the substrate 16 and the plurality of microstructures 17 and can withstand higher-intensity signal input, and has a long service life. [0019] Please refer to FIG. 2, the present invention provides a method for preparing the sounding device of the first embodiment, which specifically includes the following steps: ◎ [〇〇2〇] Step 1 'provides a substrate having a surface [0021] Step 2: forming a plurality of microstructures on the surface of the substrate; [0022] The step is specifically: engraving a plurality of micro protrusions on the surface of the substrate by an etching process to form a plurality of olive structures such as light Etching, electron beam etching or ion beam etching. [0023] Step 3, forming a sacrificial layer on the surface of the substrate to fill the gap between the plurality of microstructures; 098127914 Form No. A0101 Page 9 of 23, 0982047886-0 201108755 [0024] The material is an organic material having a lower decomposition temperature, and the decomposition temperature is lower than the melting point of the metal film in the substrate and the sounding device, preferably an organic material which can be completely decomposed below 450 ° C, such as acrylic resin or Nitrocellulose. This embodiment is an acrylic resin. The thickness of the sacrificial layer is not limited. [0025] The preparation method of the sacrificial layer specifically comprises: firstly, providing an organic polymer solution composed of a polymer, a plasticizer, a solvent and a co-solvent according to a certain proportion. The polymer comprises polyisobutyl methacrylate and acrylic B-72 resin, the plasticizer may be dibutyl phthalate, the solvent comprises ethyl acetate and butyl acetate, the cosolvent Including anhydrous ethanol and n-butanol, the specific configuration of the polymer solution in this embodiment is shown in Table 1; secondly, the polymer solution is uniformly applied to the substrate by manual coating or spin coating. The surface is allowed to stand for a while to form a sacrificial layer. In addition, in the preparation method, in order to reduce the surface tension of the solid, it is advantageous for the polymer solution to spread and spread on the specific surface, or the uneven substrate may have a smooth surface, and the polymer may be further coated. The substrate is wetted with water or water solution for 1 minute to 10 minutes before the solution.克 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 07克 resin grams plasticizer phthalic acid 20.5 ml ~ 4 ml 1 ml form number A0101 page 10 / total 23 page 0992047886-0 098127914 201108755 Butyl ester solvent ethyl acetate 50 ml ~ 64 mA 64 ML liter solvent butyl acetate 15 ml ~ 30 ml 21 ml liters help solvent absolute ethanol 1 ml ~ 3 ml 1 ml co-solvent n-butanol 1 house liter ~ 3 liters 1 ml step four, formed on the surface of the sacrificial layer a metal film; [0028] the material of the metal film is a metal material having low heat capacity or good ductility, such as iron, nickel, diamond, silver, copper, gold, rhenium, indium, bismuth, indium, indium or lead. The specific preparation method of the metal film is a physical vapor deposition method such as a vacuum evaporation method or a magnetron sputtering method. By this method, a metal film having a small thickness can be formed on the surface of the sacrificial layer, and the metal film can be prevented from being directly formed on the substrate and integrated with the substrate. [0029] Step five, heating the sacrificial layer until the sacrificial layer is completely decomposed to form the sounding element; [0030] heating the sacrificial layer between the substrate and the metal film until the sacrificial layer is completely decomposed, During the decomposition of the sacrificial layer, as the thickness of the sacrificial layer becomes thinner, the metal film formed on the surface of the sacrificial layer gradually decreases under the action of gravity, thereby contacting the metal film with the microstructure of the substrate. . Since the decomposition temperature of the sacrificial layer is lower than the melting points of the metal film and the substrate, after the sacrificial layer is completely decomposed, the metal film and the substrate are not melted, and do not occur each other due to melting. The phenomenon of combining. Therefore, after the sacrificial layer is removed, the surface of the metal film and the substrate will be suspended by the plurality of microstructures, such that 098127914 Form No. A0101 Page 11 / Total 23 Page 0982047886-0 201108755 Metal film and air or Its material body or liquid medium has a larger contact area. [0033] [0034] Further, the step further includes providing at least two electrodes to dry and separate the two electrodes by conductive paste to the surface of the sounding element, namely Jin Guanglin. The small scale '* is for the wheel to enter the device, so that the signal input device is electrically connected to the sounding element' to form a thermo-acoustic device. The signal wheel device may be an audio input device such as an Mp3, a radio, or a power amplifier, etc., and the signal input device may be directly connected to the material metal through a transfer line, or the signal may be transmitted to the device by the device. Electrical connection is made to the gold > 8 film by at least two electrodes, the signal input device being connected to the electrodes by wires. The preparation method of the present invention is characterized in that a surface of the substrate is formed by forming a complex::H and then forming a sacrificial layer to fill a gap between the plurality of microstructures. A metal having a thin thickness is deposited on the surface of the sacrificial layer. The film is then removed by heating with the sacrificial layer to obtain the sounding element. It can be seen that, in the whole process, the sacrificial layer can be removed by heating, so that the metal film can be self-supported through the plurality of microstructures and the surface portion of the substrate is suspended. The so-called self-supporting system refers to It does not need to be supported by a support body, and it can maintain its own specific shape without damage. That is, the metal film portion is supported by the plurality of microstructures, partially suspended from the support, and the partially suspended metal film can be formed in situ. The so-called in-situ formation means that the metal film is in the process of achieving a dangling setting. The relative position with the substrate and the complex microstructure 098127914 Form No. A0101 Page 12 of 23 page 0982047886-0 201108755 ❹ [0036] [0036] The Ο shift is smaller, and its relative position is closer. Therefore, the formation process does not easily cause the relative position of the reduced structure of the base metal to be damaged to cause damage, and the metal film can be suspended at the same time. It can be seen that the preparation method of the present invention allows a metal film having a relatively thin thickness to be cut by a plurality of microstructures and partially suspended. The metal film of the same material, the metal film with a smaller thickness than the thicker gold film has a smaller heat capacity per unit area, and the sound frequency is wide and the sound intensity is high. The plurality of microstructures provide a Wei cut for the gold light, so that the sounding device is not easily broken during use; and at the same time, the surface of the substrate is suspended from the metal film to ensure that the metal crucible has as much heat dissipation as possible. The area and the desired sounding effect β. Referring to FIG. 3, a second embodiment of the present invention provides a thermal sound generating device 2, including a signal input device 22, a sound emitting element 24, and at least two electrodes. The sounding element 24 includes a substrate 26, a plurality of microstructures 27, and a metal film 25'. The substrate 26 has a surface 262. The microstructure 27 is disposed on the surface 262 of the substrate 26. The metal film 25 is disposed thereon. The plurality of microstructures 27 are disposed, and are disposed by the complex microstructures 27 and the substrate 26. The at least two electrodes 28 are spaced apart and electrically connected to the metal film μ. The at least two electrodes 28 are electrically connected to the two ends of the signal input device 22 via external wires 29 for inputting the electrical signals in the signal input device 22 into the sound emitting element 24. The structure of the present embodiment is substantially the same as that of the above-described first embodiment of the thermoacoustic device 1A, except that the microstructure 27 of the present embodiment is a particle, and the metal film 25 is disposed on the plurality of particles. 098127914 Form No. 101 0101 Page 13 of 23 0982047886-0 [0037] The particles are uniformly dispersed on the surface 262 of the substrate 26, the particles having a diameter of less than 1 micron. The material of the particles is not limited and may be a hard material such as diamond, glass or quartz. Preferably, the material of the plurality of particles should have better thermal insulation properties, so that the excessive heat generated by the metal film 25 is prevented from being absorbed by the plurality of particles, and the purpose of heating the surrounding gaseous medium is not achieved. Further, the surface 262 of the substrate 26 may be provided with an adhesive layer for bonding and fixing the plurality of particles. The type of the adhesive to be selected for the adhesive layer is not limited, and it is only necessary to ensure that the plurality of particles in the embodiment are uniformly fixed to the surface 262 of the base 26. [0039] Please refer to FIG. 4, the present invention provides a method for fabricating the sounding device of the second embodiment, which specifically includes the following steps: [0040] Step 1 provides a substrate having a surface; [0041] Step 2 Forming a plurality of microstructures on a surface of the substrate; [0042] Step 3, forming a sacrificial layer on the surface of the substrate to fill a gap between the plurality of microstructures; [0043] Step 4, at the sacrificial layer Forming a metal film on the surface; [0044] step five, heating the sacrificial layer until the sacrificial layer is completely decomposed to form the sound emitting element; [0045] step six, providing a signal input device to enable the signal input device Electrically coupled to the sound emitting element to form a thermal sounding device. The method for preparing the sound generating device of the present embodiment is basically the same as the method for preparing the sound generating device of the first embodiment, and the difference is that the plurality of microstructures formed by the second step of the method for preparing the sound generating device of the embodiment are particles. Specific 098127914 Form No. A0101, page 14 / 23 pages 0982047886-0 201108755 is: first, an adhesive layer is coated on the surface of the substrate; secondly, a plurality of particles are provided, and the plurality of particles are uniformly dispersed in the The surface of the adhesive layer is such that the plurality of particles are fixed to the surface of the substrate to form a plurality of microstructures. [0048] The thermal sound generating device and the method for fabricating the same according to the embodiments of the present invention have the following advantages: since the metal film in the thermal sound generating device is supported by the substrate and the plurality of microstructures, the metal film is Even if the thickness is small, it can withstand high-intensity signal input without deformation, and thus has higher vocal intensity; the metal film prepared by the preparation method of the invention can have a thickness of less than 0.7 μm and the smaller the thickness, the unit The smaller the area heat capacity, the unit heat capacity of the unit surface can be less than 2x1 〇 _ 4 joules per square centimeter Kelvin, and the sound frequency of the metal film is closely related to the heat capacity per unit area, the smaller the heat capacity per unit area, the sound frequency range The wider the sound wave is, the higher the sound intensity is. Therefore, the sounding device of the present invention has a wide range of sounding frequencies and a sound intensity of 13⁄4. The preparation method of the present invention can make the prepared metal joint and the surface of the substrate be suspended to make the metal film and the surrounding area. The medium has a large contact area. During operation, the metal film can rapidly exchange heat with the surrounding medium and rapidly expand the surrounding medium. Shrink, and then emit sound the human ear can perceive it. In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, which is not intended to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art will be encompassed by the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of a thermo-acoustic device according to a first embodiment of the present invention. [0052] FIG. 2 is a flow chart of a method for preparing a thermoacoustic device according to a first embodiment of the present invention. 3 is a schematic structural view of a thermo-acoustic device according to a second embodiment of the present invention. [Main component symbol description] Thermal sounding device 10, 20 Signal input device 12, 22 Sounding element 14, 24 Metal film 15, 25 Base 16, 26 Surface 162, 262 Microstructure 17, 27 Electrode 18, 28 Conductor 19, 29 098127914 Form No. A0101 Page 16 / Total 23 Page 0992047886-0