200403123 玖、發明說明： 【發明所屬之技術領域】 發月有關之半導體製造技術之接合工具係使用於以 倒裝片万式將超骨波能施加於半導體元件，接合於基 極者。 【先前技術】 倒裝片緊密裝配方式係於半導體元件背面以2次元配置 入义屯極％子干凸物直接將該焊凸物以金屬接合 於基板側之電極端子之緊密裝配方式。本方式因能以短距 離連接多數輸出入端子數減小緊密裝配面積，故適於高速 工作兀件之南密度緊參卷·两 東*裝配，扭用本方式之緊密裝配數已 急速增加。 以倒裝片方式將半導髀$杜 ^ 令7L件S岔裝配於基板之方法之 一有以超首波振動使電柄端子 π亍<接合面相互摩擦，由界面 原子之擴散進行接合之方法。 * 大夕SAW(表面彈性波）元件 及無線用高頻《元㈣以施加超音波緊密裝配。 接合時，將超音波施加於半導體元件用之接合工具及超 首波放大器使用不銹鋼及泣士細 ^ a 乃N夂汁人鋼、超硬合金等金屬材質。 【發明内容】 發明所欲解決之課題 具前端面之硬度不足， 件之基板材料（si等）破 及表面，或因與半導體 面之形狀精度，有縮短 先前以來使用之金屬工具，因工 故緊密裝配時產生損破半導體元 片’及切斷元件時附著之切層等傷 元件之滑動之磨損等，而損及工具 85867.doc 200403123 接合工具壽命之問題。 又半導體元件之接合強度與施加之超音波強度有密切 之關係，超音波強度愈強接合強度亦愈強，惟超音波強度 過大時有元件受超音波振動而產生錯位之問題。其對策有 謀求加大接合工具之工具面，使半導體元件可内涵於工具 面内，於工具中央部設與半導體元件同尺寸之凹部，以抑 制錯位之方法等（日本專利特開2000-164636)。現今，元件 之緊密裝配於基板上之密度增高，將複數元件以狹窄間隔 緊密裝配之情形增加，惟此種高密度緊密裝配基板，為了 避免緊密裝配於周邊之元件與接合工具干擾，希望接合工 具盡量除接觸元件之部分以外避免超出之部分。 本發明之課題在於提供一種接合工具，其係可解決上述 先前技術之問題，將超音波施加於半導體元件緊密裝配於 基板時，抑制元件錯位，因半導體元件之接合工具之磨損 及破損少，工具壽命長者。 解決課題之方法 依本發明之接合工具，其特徵為由傳遞超音波振子產生 之超音波之放大器部，及接合於放大器部之工具前端部而 成，上述放大器部係由FeCoNi合金、鈿、超硬合金、金屬 陶瓷或不銹鋼中之任一種構成，上述工具前端部係選自鑽 石燒結體、立方晶氮化硼燒結體、超硬合金、陶瓷燒結體、 或金屬陶瓷中至少一種以上之物質構成。本發明人經多方 檢討可適用於超音波接合用接合工具之工具部分前端面 之材料之結果，從接合性能、工具壽命、元件之裝載位置 85867.doc 200403123 精度等觀點，得知氣相合成鑽石、鑽石燒結體、立方晶氮 化硼（以下稱cBN)燒結體較為適合。又得知適用於放大器 部之材料有選自FeCoNi合金、鉬、超硬合金、金屬陶瓷或 不銹鋼中之至少一種以上之物質。此等材質因楊氏係數 高，以高效率傳播超音波，此外，熱膨脹係數較小，故與 上述工具前端部之接合及實際使用溫度下，起因於與工具 前端部之熱膨脹之變形小，接合工具之壽命穩定性佳。 又本發明之接合工具，可構成將上述工具前端部接合於 上述放大器部。本發明之接合工具，使用選自氣相合成鑽 石、鑽石燒結體、立方晶氮化硼燒結體中之至少一種以上 物質，惟此等物質價昂，形成大型立體形狀將增加製造成 本。又此等物質硬度高，複雜之加工困難，將製成簡單形 狀之工具前端部接合於產生超音波之放大器部，即可壓低 接合工具整體之製造成本。 依本發明之接合工具，最好構成工具前端部之物質硬度 為4000kg/mm2以上。物質之耐磨性一般依其硬度而定，硬 度愈高耐磨性亦愈高。本發明之接合工具，引起磨損之原 因物質大多為構成元件之Si等半導體物質，及構成電極之 金屬物質。故使用具有上述物質同程度以下硬度之物質於 工具前端部時，將因磨損而縮短工具壽命。一般，為了使 滑動接觸之物質發揮充分之耐磨性，需要滑動接觸之對方 材料之數倍程度之硬度，接合工具以4000kg/mm2以上為 佳。 又該接合工具，最好構成工具前端部之物質熱傳導率為 85867.doc 200403123 200W/mK以上。先前之緊密裝配1邊至5mm程度之半導體 元件之超音波緊密裝配方式，僅以施加超音波將元件接合 於基板。惟由於半導體元件之大面積化，為了進行充分之 接合，更需加熱，而使用從基板侧補助加熱以超音波接合 之補助加熱超音波緊密裝配方式。此種加熱大多達15(TC 〜3 00 °C範圍。進行此種接合時，工具前端面最好溫度均 勻。本發明之接合工具，因工具前端部使用熱傳導率 200W/mK以上之物質，可將工具前端部之溫度保持均勻， 而適合於接合步驟。 於上述放大器部與工具前端部之接合，可以金屬接合進 行兩者之接合。具體而言，可適用使用活性焊材之直接接 合，及具備金屬中間層之坪接。 依本發明之接合工具之其他狀態，其特徵為放大器部使 用FeCoNi合金；鈿、超硬合金或金屬陶资，以氣相合成鑽 石覆蓋於該放大器部前端面構成。因使用於放大器部之此 等材料楊氏係數高，以高效率傳播超音波，故施加於接合 工具之超音波能以高效率有利於接含，此外，因熱膨脹係 數較小，故起因於與覆蓋在工具前端面之氣相合成鑽石之 熱膨脹之變形小，接合工具之壽命穩定性佳。又由於將氣 相合成鑽石直接以氣相合成法覆蓋於放大器部，即可製造 無如上述接合部之接合工具。氣相合成法可以使用熱燈絲 法、微波電漿CVD法、電弧喷射法、燃燒焰法等鑽石氣相 合成法。 覆蓋於上述放大器部前端面之氣相合成鑽石之平均粒 85867.doc 200403123 徑以0.5 // m以上者為佳。氣相合成鑽石因其結晶粒徑變小 時結晶粒界增加，故可看出熱傳導率及硬度之下降。其結 晶粒徑為0.5微米以上者適用於超音波接合工具之工具前 端面。 同樣，覆蓋於上述放大器部前端面之氣相合成鑽石之膜 厚以l//m以上100//m以下為宜。膜厚為l//m以下時鑽石 層厚度不足，無法充分延長接合工具之壽命。又膜厚超過 100/z m時，覆蓋氣相合成鑽石成本提高，一方面無法發揮 更長壽命之效果。 覆蓋於上述放大器部前端面之氣相合成鑽石之硬度，與 上述狀態焊接於接合工具前端部之工具前端部同樣理 由，以400 Okg/mm2以上為佳。緊密裝配之半導體元件材質 硬度高時，接合工具前端部之材料亦要求更高之硬度。氣 相合成鑽石，因選擇氣相合成之條件可合成硬度更高之鑽 石，故緊密裝配藍寶石等高硬度之半導體元件時，覆蓋於 放大器部前端面之氣相合成鑽石之硬度以6000kg/mm2以 上為更佳。 此外，本發明之接合工具，最好工具前端面之表面粗細 於最大表面粗細（Rt ··將測定曲線以每基準長度區分，於各 基準長度間求平均線至最深谷之深度者之最大值之最大 谷深，與各基準長度間求平均線至最高山之高度者之最大 值之最大山高之和）為〇·1μιη以上10"m以下。工具前端面 之表面粗細為Rt未滿0.1 // m時，接合時接合工具之工具面 與被接合之元件或電極之間容易發生錯位。又工具前端面 85867.doc -10- 200403123 之表面粗細為Rt超過1 0 // m時，以工具前端面傷及被接合 之元件或電極，招致製造上不良之結果。又接合工具之工 具前端面之表面粗細從接合工具對被接合之元件或電極 傳播超音波能之效率有很大之影響。為了有效傳播超音波 能，工具面之表面粗細Rt最好為0.2// m以上5// m以下，更 好為0.5/zm以上3//m以下。 為了避免被接合之元件或電極在接合時發生錯位，最好 採取於接合工具前端面，工具前端面之接觸半導體元件部 分之外緣部分大於其内側部分之表面粗細之結構。此外上 述外緣部分最好為工具前端面之接觸半導體元件部分之 面積之20%以上3 0%以下。表面粗度大之部分，因更牢固 把持被接合之元件或電極，故將此種表面較粗部分設於工 具前端面之周邊部分，在接合時即不易發生元件或電極之 錯位。 【實施方式】 發明之實施形態 以下用實施例說明本發明之超音波接合用接合工具。 實施例1 · 製作工具前端部材料以具有燒結鑽石、覆蓋氣相合成鑽 石之陶瓷成形體、及立方晶氮化硼燒結體之超音波接合工 具。工具前端部係成形為必要之形狀後，進行工具面之表 面粗細之調整。工具面之表面粗細Rt為0.2 // m以下者係研 磨工具面表面者，而Rt大於0 · 2 /z m小於5 /z m者係以平面研 削加工修飾工具面表面者。Rt大於5 /z m者係工具面表面之 85867.doc -11 - 200403123 平面研削加主後，以雷射加工進行加粗面之處理。放大器 部係將FeNiCo合金、鉬、超硬合金、不銹鋼及金屬陶瓷分 別加工成超音波放大器之形狀。 於真空爐内用活性焊材以金屬接合上述工具前端部與 放大器部，做為超音波工具。工具前端部與放大器部之材 質組合，製作表1所示者。接合後，更以鋼絲放電加工、 鑽石磨石之平面研削加工，將形狀整理為必要之尺寸精密 度及角度精密度。經此等加工後，以放電加工及YAG雷射 加工製作吸住半導體元件用之貫穿孔。又使工具前端面之 尺寸與緊密裝配之半導體元件同尺寸。又為比較計，工具 前端部材料使用SiC陶瓷者，及不特別使用工具前端部， 製作將鉬製放大器部延伸至工具前端部之先前型之接合 工具。所製造之各接合工具規格如表1。 使用上述結構準備之超音波接合工具，進行半導體元件 用之接合。圖1係緊密裝配時之模式圖。接合係用以下步 騾實施。以接合工具真空吸住半導體元件背面，搬至配置 在接合載物上之基板上。進行對準半導體元件之電極端子 (焊凸物）與基板電極端子位置，降落工具至電極端子彼此 間接觸處旋加超音波，將半導體元件之全電極端子總括緊 密裝配於基板上之端子。此時之超音波輸出為20W，頻率 為60KHz施加約1秒鐘。以本條件，1·1〜1·5、1-8及1-9之接 合工具緊密裝配5X5mm之Si晶片，1-6及1-7之接合工具緊 密裝配1 X 1mm之GaAs晶片，確認半導體元件之各焊凸物 之緊密裝配狀態，及接合工具之損傷狀況，進行至最大 85867.doc = 12 - 200403123 200,000個之緊密裝配。又大尺寸之5X 5mm之晶片緊密裝 配，不僅以施加超音波並以内裝於接合載物之加熱器邊從 背面加熱至約200°C邊緊密裝配。 【表1】 放大器 部材質 前端面材質 前端面 之硬度 前端面之 熱傳導率 表面粗度Rt 1-1 不銹鋼 燒結鑽石 7500 300 0.02 1-2 鉬 cBN 4000 80 0.2 1-3 金屬陶瓷 cBN 4500 100 12.0 1-4 FeNiCo 燒結鑽石 7500 300 0.2 1-5 鉬 氣相鑽石 10000 1000 0.1 1-6 超硬合金 氣相鑽石 10000 1000 5.0 1-7 金屬陶瓷； cBN 4500 100 1.0 1-8 FeNiCo SiC 2500 70 0.2 1-9 鉬 —— 160 130 1.0 本發明之接合工具之1-1〜1-7,至進行接合工具之工業上 所企盼之壽命1〇〇,〇〇〇個之2倍之200,000個元件之緊密裝 配時止，幾乎看不出工具表面之劣化損壞，於半導體元件 之緊密裝配亦可得良好之接合狀態。針對此，於1〜8，在 20,000個緊密裝配時，工具面之表面粗度變粗，外周部電 極之接合狀態惡化。認為此乃因於工具外周部與元件滑動 之磨損進展，致工具面之平面度惡化，超音波無法均勻傳 遞至元件之全桿凸物之故。工具前端部繼續使用放大器部 之鉬之1〜8，5,000個緊密裝配，工具前端之磨損進展，外 85867.doc -13 - 200403123 周部電極之無合即無法進行。 用1-1緊密裝配之半導體元件中，連接電極之意並無問 題，惟發現有引起錯位者，可認為此乃因1-1之工具面之表 面粗度小，緊密裝配中接合工具與元件間產生錯位之故。 又緊密裝配200,000個後測定工具前端面之平坦度結果， 1-1中央部變形為約5// m凸狀。1-2〜1-7並未看出有平坦度 之變化。此原因認為因不銹鋼與燒結鑽石之熱膨脹係數差 之熱變形之影響。又緊密裝配約15,000個之途中以紅外線 輻射溫度計測定接合工具前端面之溫度不均之結果，看出 1-2之工具前端面對載物之設定溫度200°C有150°C ±20°C 之溫度之不均，周邊部之溫度特別低。其外之1-1及1-3〜1-7 之工具，工具前端面之溫度之不均同樣對載物之設定溫度 200°C有150°C ±5°C以内之溫度差。觀察緊密裝配後半導體 元件之表面結果，使用1-3之工具進行緊密裝配者，有於元 件表面看出微小擦痕者，惟使用1-1〜1-2及1-4〜1 »7之工 具，進行緊密裝配者，則未看出類似之痕跡。 實施例2 用FeNiC〇合金、鈿、超硬合金、及金屬陶资製作超音波 接合工具之放大器部，於此等放大器部前端面以氣相合成 法覆蓋鑽石膜。氣相合成法使用熱燈絲CVD法。 熱燈絲CVD法之合成條件係將原料氣體流量為H2 : 10〜lOOsccm、CH4 : 1 〜5sccm，將燈絲溫度為 1500〜2200°c， 基板溫度：500〜900°C，壓力：10〜500Torr，因應所需膜厚 改變合成時間予以合成。覆蓋鑽石膜後，鑽石膜厚較厚、 85867.doc -14- 200403123 鑽石面平面度及表面粗細未滿所需精度者，以鑽石磨石研 削、研磨加工成所需要之形狀。又為了比較，以不銹鋼製 作放大器部，以氣相合成法將鑽石膜覆蓋於該工具前端 面，以上述相同之步.驟製作接合工具。 用上述步騾製作之接合工具，以實施例1之1-1〜1-5相同 之方法接合200,000個半導體元件。元件之尺寸係5 X 5mm，並將工具前端面尺寸亦採與此相同者。將被覆之鑽 石膜粒徑、厚度、表面粗細及硬度彙整如表2。又鑽石膜 之熱傳導率及硬度係以同條件加粒徑合成為約100 //m厚度 之試驗樣品測足。 【表2】 放大器部 鑽石膜厚 βΤΆ 粒徑 βτη 表面粗度Rt 硬度 kg/mm2 2-1 鉬 0.8 1 0.5 5000 2-2 超硬合金 5 0.1 0.08 4500 2»3 金屬陶資； 5 0.1 0.1 4000 2-4 FeNiCo 40 20 8 10000 2-5 鉬 1 0.5 3 8000 2-6 超硬合金 60 30 0.1 10000 2-7 金屬陶瓷； 100 50 0.2 10000 2-8 不銹鋼 50 20 10 10000 本發明之接合工具之2-1〜2-7，緊密裝配200,000個後工 具面並無劣化，獲得良好之緊密裝配結果。2-8因放大器部 使用熱膨脹率大之不銹鋼，故合成後多晶鑽石剝落而無法 85867.doc -15- 200403123 達成緊密裝配。2-1於緊密裝配200,000個後於接合工具前 端面之一部分有露出放大器部之鉬之部分。認為覆蓋之鑽 石膜厚度較薄之故，惟尚未妨礙緊密裝配本身。使用2-2 之工具緊密裝配者，並未獲得良好連接半導體元件全面焊 凸物之狀態。此係與1-1同樣，因工具前端面之表面粗度 小，致接合工具與半導體元件產生微小錯開位置之故。2-3 於緊密裝配200,000個後於工具前端面之尤其周邊部看出 因輕度磨損之變形。 實施例3 製作5種以雷射加工將實施例1之1-1試作者同規格之接 合工具前端面改變局部粗度之工具，以實施例1相同之方 法接合5000個半導體元件。製作之接合工具均將工具前端 面之外周部分表面粗細形成大於中央部，改變對表面粗度 大之部分之工具前端面全面面積之比例。並製作未設粗面 之工具，進行同樣之緊密裝配評估。圖2係製作之接合工 具之工具前端面之平面模式圖。表3係接合之結果。 【表3】 粗面比例 詳細狀況 3-1 10% 40W以上發生基板電極與元件焊凸物錯位 3-2 20% 全範圍良好接合 3-3 30% 全範圍良好接合 3-4 40% 60W以上接合良好惟傷及晶片内 3-5 60% 50W以上接合良好惟傷及晶片内 3-6 0% 25W以上發生基板電極與元件焊凸物錯位 85867.doc -16- 200403123 任何一種接合工具均由適當選擇接合條件即可接合，惟 3-1在超音波輸出40W以上時，一部分半導體元件之焊凸物 與基板電極剛接合處，產生元件與工具之錯位，雖能以電 接含，惟元件稍與一定位置錯位接合。3-2及3-3獲得良好 之連接。3-4及3-5加大超音波輸出時，於元件與工具面接 觸部分之一部分有削過痕跡者。無加粗表面粗度部分之3-6 以小於3-1之超音波能即產生元件錯位。由此結果，可知粗 面比例20〜30°/。範圍可適用於最廣之接合條件。 發明之效果 本發明之超音波接合工具，因接觸半導體元件之工具前 端部使用高硬度、熱傳導率良好之材質，故能同時實現接 合工具之長壽命化與接合性能之高度化。又由適度調整工 具前端面之表面粗細，可達成超音波能之有效傳播與元件 錯位之防止。 【圖式簡單說明】 圖1係實施例1之超音波接合工具之概念圖。 圖2係實施例3之超音波接合工具之工具前端面說明圖。 【圖式代表符號說明】 1 * * ·工具前端部 2 · · ·超音波放大器部 3···超音波產生裝置 4 · * · XYZ軸驅動機構 5 · · ·接合工具支持臂 6 · · ·半導體元件 85867.doc ^ 17- 200403123 7 · · •基板 8 ···含加熱機構之載物 11 · · ·粗面部分 12 · · ·中央部分 1 3 ···半導體元件吸件孔 -18- 85867.doc200403123 发明 Description of the invention: [Technical field to which the invention belongs] A bonding tool related to semiconductor manufacturing technology is used to apply super bone wave energy to a semiconductor element in a flip-chip manner, and to bond it to a base. [Previous technology] The flip-chip close-packing method is a close-packing method in which the semiconductor element is arranged in a two-dimensional arrangement on the backside of the semiconductor element, and the solder bumps are directly metal-bonded to the electrode terminals on the substrate side. This method can connect most I / O terminals with a short distance to reduce the tight assembly area, so it is suitable for high-speed work parts with a high density of south and two east * assemblies. The number of tight assemblies that use this method has increased rapidly. One of the methods of assembling a semiconducting element by flip chip is to assemble 7L pieces of S on a substrate. The super-first-wave vibration is used to rub the handle terminals π 亍 < the joint surfaces against each other, and the surfaces are bonded by diffusion of interface atoms Method. * Daxi SAW (Surface Elastic Wave) components and wireless high-frequency "Yuanzhang" are tightly assembled by applying ultrasonic waves. At the time of bonding, a bonding tool for applying ultrasonic waves to a semiconductor device and a super wave amplifier are made of stainless steel and oscillating steel. ^ A is made of metal materials such as stainless steel and super-hard alloy. [Summary of the Invention] The problem to be solved by the invention is insufficient hardness of the front end surface, the substrate material (Si, etc.) of the component is broken and the surface, or the shape accuracy of the semiconductor surface is shortened, and the metal tool used previously has been shortened due to work reasons. During close assembly, wear and tear of damaged components such as damage to the semiconductor element wafer and cutting layers attached when the component is cut off, etc., may impair the life of the tool 85867.doc 200403123 bonding tool. In addition, the bonding strength of semiconductor components is closely related to the applied ultrasonic intensity. The stronger the ultrasonic intensity is, the stronger the bonding strength is. However, when the ultrasonic intensity is too large, the component will be distorted by ultrasonic vibration. The countermeasures are to increase the tool surface of the bonding tool so that the semiconductor element can be contained in the tool surface, and a method of setting a concave portion with the same size as the semiconductor element in the center of the tool to suppress misalignment (Japanese Patent Laid-Open No. 2000-164636). . At present, the density of tightly assembled components on a substrate is increased, and the number of tightly assembled components is increased at a narrow interval. However, in order to avoid interference between closely assembled peripheral components and bonding tools, bonding tools are expected Try to avoid the excess except the part that touches the component. The object of the present invention is to provide a bonding tool which can solve the above-mentioned problems of the prior art. When ultrasonic waves are applied to a semiconductor device and tightly mounted on a substrate, the displacement of the device is suppressed. Elderly life. A method for solving the problem The bonding tool according to the present invention is characterized by an amplifier section transmitting ultrasonic waves generated by an ultrasonic transducer, and a tool tip section connected to the amplifier section. The amplifier section is made of FeCoNi alloy, rhenium, It is composed of any one of hard alloy, cermet, or stainless steel, and the tool tip is composed of at least one selected from the group consisting of diamond sintered body, cubic boron nitride sintered body, cemented carbide, ceramic sintered body, or cermet. . The inventors have reviewed the materials that can be applied to the front end surface of the tool part of the bonding tool for ultrasonic bonding through various parties. From the viewpoints of bonding performance, tool life, and component loading position, 85867.doc 200403123 accuracy, they have learned that gas-phase synthetic diamond , Diamond sintered body, cubic boron nitride (hereinafter referred to as cBN) sintered body are more suitable. It was also found that a material suitable for the amplifier section is at least one selected from the group consisting of FeCoNi alloy, molybdenum, superhard alloy, cermet, and stainless steel. These materials have a high Young's coefficient and can propagate ultrasonic waves with high efficiency. In addition, the thermal expansion coefficient is small. Therefore, the joint with the tool tip and the actual use temperature are small due to the thermal expansion with the tool tip. Tool life stability is good. Further, the bonding tool of the present invention may be configured to bond the tip end portion of the tool to the amplifier portion. The bonding tool of the present invention uses at least one material selected from the group consisting of gas-phase synthetic diamond, diamond sintered body, and cubic boron nitride sintered body, but these materials are expensive, and forming a large three-dimensional shape will increase the manufacturing cost. In addition, these materials have high hardness and complex processing difficulties. Joining the tip of a simple tool to the amplifier section that generates ultrasonic waves can reduce the overall manufacturing cost of the bonding tool. According to the joining tool of the present invention, it is preferable that the material hardness of the front end portion of the tool is 4000 kg / mm2 or more. The abrasion resistance of a substance is generally determined by its hardness. The higher the hardness, the higher the abrasion resistance. In the bonding tool of the present invention, most of the causes of abrasion are semiconductor materials such as Si constituting elements and metal materials constituting electrodes. Therefore, the use of a substance with a hardness equal to or less than the aforementioned substance at the tip of the tool will shorten the tool life due to wear. Generally, in order to achieve sufficient abrasion resistance of the material in sliding contact, it is necessary to have a hardness of several times that of the material of the counterpart in sliding contact. The joining tool is preferably at least 4000 kg / mm2. The bonding tool preferably has a material thermal conductivity of 85867.doc 200403123 200W / mK or more. In the previous ultrasonic tight assembly method for semiconductor devices that were tightly assembled from one side to 5 mm, the devices were bonded to the substrate only by applying ultrasonic waves. However, due to the large area of semiconductor devices, in order to achieve sufficient bonding, more heating is required, and supplementary heating from the substrate side is supplemented with ultrasonic bonding. This type of heating is as large as 15 (TC ~ 3 00 ° C. When performing this type of bonding, the temperature of the tip surface of the tool is preferably uniform. The bonding tool of the present invention can use a material with a thermal conductivity of 200 W / mK or more at the tip of the tool. The temperature of the tool tip is kept uniform, which is suitable for the bonding step. For the above-mentioned joining of the amplifier section and the tool tip, metal bonding can be used to bond the two. Specifically, direct bonding using active welding materials can be applied, and A flat interface with a metal intermediate layer. According to other states of the bonding tool of the present invention, the amplifier section is made of FeCoNi alloy; rhenium, cemented carbide or metal ceramics is covered with a vapor-phase synthetic diamond on the front end surface of the amplifier section. Because these materials used in the amplifier section have high Young's coefficients and propagate the ultrasonic waves with high efficiency, the ultrasonic waves applied to the bonding tool are beneficial for inclusion with high efficiency. In addition, due to the small thermal expansion coefficient, they are caused by The thermal expansion deformation is small with the gas-phase synthetic diamond covering the front surface of the tool, and the life stability of the bonding tool is good. The stone is directly covered by the gas phase synthesis method in the amplifier section, and a bonding tool without the above-mentioned joint can be manufactured. The gas phase synthesis method can use diamond gas such as a hot filament method, a microwave plasma CVD method, an arc spray method, and a combustion flame method. Phase synthesis method. The average grain size of the gas-phase synthetic diamond covering the front end surface of the amplifier section is 85867.doc 200403123. The diameter of the gas-phase synthetic diamond is preferably 0.5 // m or more. The gas-phase synthetic diamond has a larger crystal grain boundary because the crystal grain size becomes smaller. Therefore, it can be seen that the thermal conductivity and hardness decrease. The crystal particle size of 0.5 micrometers or more is suitable for the tool front surface of the ultrasonic bonding tool. Similarly, the film thickness of the gas-phase synthetic diamond covering the front surface of the amplifier section is l The thickness of // m is more than 100 // m. The thickness of the diamond layer is insufficient when the film thickness is 1 // m or less, and the life of the bonding tool cannot be sufficiently extended. When the film thickness exceeds 100 / zm, the cost of covering gas-phase synthetic diamond increases. On the one hand, the effect of longer life cannot be exerted. The hardness of the gas-phase synthetic diamond covering the front end surface of the amplifier section is welded to the tool front end section of the joint tool front end as described above. For the same reason, it is better to be above 400 Okg / mm2. When the material of the tightly assembled semiconductor element is high in hardness, the material of the front end of the bonding tool also requires higher hardness. Gas-phase synthetic diamond can be synthesized due to the choice of gas-phase synthesis conditions Higher diamonds, so when tightly mounting high-hardness semiconductor components such as sapphire, the hardness of the gas-phase synthetic diamond covering the front end surface of the amplifier is preferably 6000 kg / mm2 or more. In addition, the bonding tool of the present invention is the best tool The surface thickness of the front end surface is greater than the maximum surface thickness (Rt ····································································· The sum of the maximum heights of the maximums from the average line to the height of the highest mountain) is above 0.1 μm and below 10 " m. When the surface thickness of the front end surface of the tool is less than 0.1 // m, misalignment easily occurs between the tool surface of the bonding tool and the component or electrode to be bonded during bonding. When the surface thickness of the front end of the tool 85867.doc -10- 200403123 is Rt exceeding 1 0 // m, the front end of the tool hurts the component or electrode to be joined, resulting in poor manufacturing results. The thickness of the surface of the front end surface of the tool of the bonding tool has a great influence on the efficiency of transmitting ultrasonic energy from the bonding device or electrode. In order to effectively propagate the ultrasonic energy, the surface thickness Rt of the tool surface is preferably 0.2 // m to 5 // m, and more preferably 0.5 / zm to 3 // m. In order to avoid misalignment of the bonded component or electrode during bonding, it is preferable to adopt a structure in which the outer edge portion of the front end surface of the tool contacting the semiconductor element portion is larger than the surface thickness of the inner portion thereof. In addition, the above-mentioned outer edge portion is preferably 20% or more and 30% or less of the area of the front end surface of the tool that contacts the semiconductor element. For the part with a large surface roughness, the bonded component or electrode is more firmly held. Therefore, if such a rougher surface is provided on the peripheral part of the front end surface of the tool, the component or electrode will not be easily displaced during bonding. [Embodiment] Embodiments of the invention The following describes the bonding tool for ultrasonic bonding of the present invention using examples. Example 1 The material of the front end of the tool was an ultrasonic bonding tool having a sintered diamond, a ceramic formed body covering a vapor-phase synthetic diamond, and a cubic boron nitride sintered body. After the tool tip is formed into a necessary shape, the surface thickness of the tool surface is adjusted. The tool surface thickness Rt is less than 0.2 // m is for grinding the tool surface, and Rt is greater than 0 · 2 / z m is less than 5 / z m is for the surface modification of the tool surface. Those with Rt greater than 5 / z m are 85867.doc -11-200403123 of the surface of the tool. After plane grinding and adding, laser processing is used to make the rough surface. The amplifier unit processes FeNiCo alloy, molybdenum, cemented carbide, stainless steel, and cermet into the shape of an ultrasonic amplifier, respectively. The front end portion of the tool and the amplifier portion were metal-bonded with an active welding material in a vacuum furnace as an ultrasonic tool. The materials of the tool tip part and the amplifier part were combined to produce the one shown in Table 1. After joining, the wire is further processed by electric discharge machining of the wire and diamond grinding stone, and the shape is adjusted to the necessary dimensional accuracy and angular accuracy. After these processes, through-holes for absorbing semiconductor elements are produced by electric discharge machining and YAG laser machining. In addition, the dimensions of the front surface of the tool are the same as those of the closely-assembled semiconductor components. For comparison purposes, those who use SiC ceramics as the material for the front end of the tool, and who do not particularly use the front end of the tool, make a conventional type of joining tool that extends the molybdenum amplifier section to the front end of the tool. Table 1 shows the specifications of each bonding tool manufactured. The ultrasonic bonding tool prepared as described above was used for bonding semiconductor devices. Figure 1 is a schematic diagram of a close assembly. The joining system is performed by the following steps. The back surface of the semiconductor element is vacuum-sucked with a bonding tool and transferred to a substrate placed on a bonding carrier. Align the positions of the electrode terminals (soldering bumps) of the semiconductor element and the substrate electrode terminals, and apply ultrasonic waves to the contact points between the electrode and the landing tool. The all-electrode terminals of the semiconductor element are tightly assembled to the terminals on the substrate. At this time, the ultrasonic output is 20W, and the frequency is 60KHz and applied for about 1 second. Under these conditions, 5x5mm Si wafers are tightly assembled with the bonding tools of 1 · 1 ~ 1 · 5, 1-8, and 1-9, and 1x1mm GaAs wafers are tightly assembled with the bonding tools of 1-6 and 1-7 to confirm the semiconductor. The tight assembly state of each solder bump of the component and the damage status of the bonding tool are up to a maximum of 85867.doc = 12-200403123 200,000. The large-sized 5X 5mm wafers are tightly packed, not only by applying ultrasonic waves and heating them from the back to about 200 ° C by a heater built into the joint carrier. [Table 1] Material of the front-end surface of the amplifier section Hardness of the front-end surface Material Thermal conductivity of the front-end surface Rt 1-1 Stainless steel sintered diamond 7500 300 0.02 1-2 Molybdenum cBN 4000 80 0.2 1-3 Cermet cBN 4500 100 12.0 1 -4 FeNiCo sintered diamond 7500 300 0.2 1-5 molybdenum vapor phase diamond 10000 1000 0.1 1-6 cemented carbide gas phase diamond 10000 1000 5.0 1-7 cermet; cBN 4500 100 1.0 1-8 FeNiCo SiC 2500 70 0.2 1- 9 Molybdenum-160 130 1.0 Tight assembly of 1-1 to 1-7 of the joining tool of the present invention to 200,000 components twice the life expectancy of 100,000 in the industry of joining tools From time to time, the deterioration of the tool surface can hardly be seen, and a good bonding state can also be obtained when the semiconductor device is tightly assembled. In view of this, from 1 to 8, when the 20,000 pieces are tightly assembled, the surface roughness of the tool surface becomes coarse, and the joining state of the outer electrode is deteriorated. It is thought that this is because the wear of the tool peripheral part and the sliding of the component deteriorates the flatness of the tool surface, and the ultrasonic wave cannot be uniformly transmitted to the full-rod protrusion of the component. The front end of the tool continues to use 1 to 8,5,000 pieces of molybdenum in the amplifier section. The wear of the front end of the tool has progressed, and the outer electrode of the peripheral section cannot be performed without the combination of 85867.doc -13-200403123. In a 1-1 close-packed semiconductor component, there is no problem in connecting the electrodes, but if it is found that it causes misalignment, it can be considered that this is because the surface roughness of the tool surface of 1-1 is small, and the tools and components are joined in close-packing Dislocation occurs. The flatness of the front end surface of the tool was measured after 200,000 pieces were tightly assembled. As a result, the center portion of 1-1 was deformed into a convex shape of about 5 / m. No change in flatness was seen from 1-2 to 1-7. This is considered to be due to the influence of thermal deformation due to the difference in thermal expansion coefficient between stainless steel and sintered diamond. In the course of close assembly of about 15,000, an infrared radiation thermometer was used to measure the temperature unevenness of the front end surface of the bonding tool. It was found that the set temperature of the front end of the tool facing the load at 1-2 was 150 ° C ± 20 ° C. The temperature is uneven, and the temperature in the peripheral portion is extremely low. For tools other than 1-1 and 1-3 ~ 1-7, the temperature unevenness on the front surface of the tool is the same as the set temperature of the load. 200 ° C has a temperature difference within 150 ° C ± 5 ° C. Observe the results of the surface of the semiconductor component after close assembly. Those who use 1-3 for close assembly will see tiny scratches on the surface of the component, but use 1-1 ~ 1-2 and 1-4 ~ 1 »7. The tool, the close assembler, did not see similar traces. Example 2 An amplifier section of an ultrasonic bonding tool was made of FeNiC0 alloy, rhenium, cemented carbide, and metallic ceramics, and a diamond film was covered on the front end surface of these amplifier sections by a vapor phase synthesis method. The gas phase synthesis method uses a hot filament CVD method. The synthesis conditions of the hot filament CVD method are as follows: the flow rate of the raw material gas is H2: 10 to 100 sccm, CH4: 1 to 5 sccm, the filament temperature is 1500 to 2200 ° c, the substrate temperature is 500 to 900 ° C, and the pressure is 10 to 500 Torr. The synthesis time is changed according to the required film thickness. After the diamond film is covered, the diamond film thickness is thicker. 85867.doc -14- 200403123 The surface of the diamond and the thickness of the surface are less than the required accuracy. The diamond grinding stone is used to grind and grind the diamond to the required shape. For comparison, a stainless steel amplifier was used, a diamond film was covered on the front end surface of the tool by a vapor phase synthesis method, and a bonding tool was manufactured in the same steps as described above. Using the bonding tool prepared in the above steps, 200,000 semiconductor elements were bonded in the same manner as in 1-1 to 1-5 of Example 1. The size of the component is 5 X 5mm, and the size of the tool front surface is also the same. The diameter, thickness, surface thickness and hardness of the coated diamond film are summarized in Table 2. The thermal conductivity and hardness of the diamond film were measured on a test sample with a particle size of about 100 // m synthesized under the same conditions and particle size. [Table 2] Diamond film thickness βΤΆ Particle size βτη Surface roughness Rt Hardness kg / mm2 2-1 Molybdenum 0.8 1 0.5 5000 2-2 Cemented carbide 5 0.1 0.08 4500 2 »3 Metal ceramics; 5 0.1 0.1 4000 2-4 FeNiCo 40 20 8 10000 2-5 Molybdenum 1 0.5 3 8000 2-6 Cemented carbide 60 30 0.1 10000 2-7 Cermet; 100 50 0.2 10000 2-8 Stainless steel 50 20 10 10000 From 2-1 to 2-7, 200,000 back tool faces have not been deteriorated, and good tight assembly results have been obtained. 2-8 Because the amplifier section uses stainless steel with a large thermal expansion coefficient, the polycrystalline diamond is peeled off after synthesis, and it is not possible to achieve a tight assembly 85867.doc -15- 200403123. 2-1 After the 200,000 pieces are tightly assembled, a part of the front end face of the bonding tool has a molybdenum portion exposing the amplifier portion. It is considered that the thickness of the covered diamond film is thin, but it has not prevented the tight assembly itself. A close assembler using a tool of 2-2 did not obtain a fully soldered state of the semiconductor device with a good connection. This is the same as 1-1, because the surface roughness of the tip surface of the tool is small, so that the bonding tool and the semiconductor element are slightly staggered. 2-3 Deformation due to slight abrasion can be seen on the front end surface of the tool, especially the peripheral portion after 200,000 pieces are tightly assembled. Example 3 Five kinds of tools were manufactured by laser processing to change the local roughness of the front end face of the bonding tool of the test author of Example 1-1 of the same specification, and 5,000 semiconductor elements were bonded in the same manner as in Example 1. All the joining tools produced have a thickness of the outer surface of the front end surface of the tool larger than that of the center portion, and the ratio of the total area of the front end surface of the tool with a large surface roughness is changed. A tool with no rough surface was made and evaluated for the same close assembly. Fig. 2 is a schematic plan view of a tool front surface of a jointing tool produced. Table 3 shows the results of joining. [Table 3] Detailed condition of rough surface ratio 3-1 10% 40W or more Dislocation of substrate electrode and component solder bump 3-2 20% Full range good joint 3-3 30% Full range good joint 3-4 40% 60W or more Good bonding but damage to the wafer 3-5 60% 50W or more, but good bonding but damage to the wafer 3-6 0% 25W or more occurs between the substrate electrode and the component solder bumps 85867.doc -16- 200403123 The bonding conditions can be selected properly. However, when the ultrasonic output is more than 40W, a part of the semiconductor element's solder bumps and the substrate electrode are just joined, which causes the component and tool to be misaligned. Although it can be electrically connected, the component Slightly misaligned with a certain position. 3-2 and 3-3 get good connections. When 3-4 and 3-5 increase the ultrasonic output, there are traces on a part of the contact part between the component and the tool surface. 3-6 without roughened surface roughness will produce component misalignment with ultrasonic energy less than 3-1. From this result, it was found that the rough ratio was 20 to 30 ° /. The range can be applied to the widest range of joining conditions. Effects of the Invention The ultrasonic bonding tool of the present invention uses a material with high hardness and good thermal conductivity at the front end of the tool that contacts the semiconductor element, so that it can achieve a longer life of the bonding tool and a higher bonding performance. By appropriately adjusting the surface thickness of the front surface of the tool, the effective propagation of ultrasonic energy and the prevention of component misalignment can be achieved. [Brief Description of the Drawings] FIG. 1 is a conceptual diagram of the ultrasonic bonding tool of the first embodiment. FIG. 2 is an explanatory view of a tool front end surface of an ultrasonic bonding tool of Embodiment 3. FIG. [Illustration of Symbols in the Drawings] 1 * * · Tool tip 2 · · · Ultrasonic amplifier section 3 · · Ultrasonic generator 4 · * · XYZ axis drive mechanism 5 · · · Joint tool support arm 6 · · · Semiconductor device 85867.doc ^ 17- 200403123 7 · · · Substrate 8 ··· Load with heating mechanism 11 · · · Rough surface 12 · · · Central portion 1 3 · · Semiconductor element suction hole -18- 85867.doc