在第一態樣中，本發明係關於一種銀合金銅線，其包含線芯或甚至由線芯組成(下文亦稱簡稱為「芯」)，線芯自身由以下組成： (a)呈0.3重量% (重量% (weight-%)，重量% (% by weight))至0.7重量%、較佳0.5重量%之量的銀， (b)呈在99.25重量%至99.7重量%、較佳地99.45重量%至99.5重量%或甚至更佳地99.49重量%至99.5重量%範圍內之量的銅，以及 (c)0 wt.-ppm (重量-ppm，重量ppm)至500 wt.-ppm、較佳地0 wt.-ppm至100 wt.-ppm之另外組分(除銀及銅以外之組分)， 其中所有以重量%及wt.-ppm為單位之量按芯之總重量計。 下表彙編銀合金銅線芯之組成的各種實施例：
銀合金銅線較佳為用於微電子中之接合的接線。銀合金銅線較佳為單件式物品。眾多形狀為已知的且顯得適用於本發明之銀合金銅線。對於本發明，術語「接線」包含所有形狀之橫截面及所有常見線直徑，但具有圓形橫截面及薄直徑之接線為較佳的。平均橫截面在(例如)50 µm2
至5024 µm2
或較佳地110 µm2
至2400 µm2
之範圍內；因此在較佳圓形橫截面之情況下，平均直徑在(例如)8 µm至80 µm或較佳地12 µm至55 µm之範圍內。 可藉由「定尺寸方法」獲得線或線芯之平均直徑或簡言之直徑。根據此方法測定限定長度的銀合金銅線的物理重量。基於此重量，使用線材料密度計算線或線芯之直徑。直徑經計算為特定線之五個切口上的五個量測值之算術平均值。 與前述一致，線芯以前文所揭示之比例比值包含(a)銀及(b)銅。然而，本發明之銀合金銅線的芯可包含呈0 wt.-ppm至500 wt.-ppm、較佳地0 wt.-ppm至100 wt.-ppm之總量的(c)另外組分。在本上下文中，另外組分，通常亦稱作「不可避免的雜質」，為源自存在於所使用之原材料中的雜質或源自線製作方法的少量化學成分及/或化合物，亦即，(c)類型之另外組分的存在可(例如)源自存在於銀及/或銅中之雜質。該等另外組分之實例為：Au、P、Ni、Pd、Fe、Si、Mn、Cr、Ce、Mg、La、Al、B、Zr、Ti、S等。低總量之0 wt.-ppm至500 wt.-ppm或甚至0 wt.-ppm至100 wt.-ppm的另外組分(c)確保線特性之良好再現性。通常不分開添加存在於芯中之另外組分(c)。 在一實施例中，本發明之銀合金銅線的芯包含少於15 wt.-ppm量之以下每一者的另外組分(c)： Au、P、Ni、Pd、Fe、Si、Mn、Cr、Ce、Mg、La、Al、B、Zr、Ti、S。 本上下文中之銀合金銅線的芯經定義為塊狀材料之均質區域。由於任何塊狀材料始終具有可在一定程度上展現不同性質之表面區域，因此線之芯的特性理解為塊狀材料之均質區域的特性。塊狀材料區域之表面可在形態、組成(例如氯及/或氧含量)及其他特徵方面不同。表面可為線芯之外表面；在該實施例中，本發明之銀合金銅線由線芯組成。在一替代方案中，表面可為介於線芯及疊加於線芯上之塗層之間的界面區域。 在本發明之上下文中的術語「疊加」用於描述第一物品(例如線芯)相對於第二物品(例如塗層)之相對位置。「疊加」表徵為諸如中間層之另外物品可(但不需要)配置於第一物品及第二物品之間。較佳地，第二物品至少部分地疊加於第一物品上，例如達至少30%、50%、70%或達至少90%，各者相對於第一物品之總表面。最佳地，第二物品完全疊加於第一物品上。 在本發明之上下文中的術語「中間層」係指銀合金銅線介於其芯及疊加於其上之塗層之間的區域。在此區域中，存在芯與塗層兩者之材料的組合。 在本發明之上下文中，術語「厚度」用於定義層在垂直於芯之縱向軸線的方向上的尺寸，該層至少部分地疊加於芯之表面上。 在一實施例中，芯具有表面，其中將塗層疊加於芯之表面上。 在一實施例中，塗層之質量不超過5重量%，較佳地2重量%或低於2重量%，各者相對於芯之總質量。當存在塗層時，其通常具有0.1重量%或高於0.1重量%、或0.5重量%或高於0.5重量%之最小質量，各者相對於芯之總質量。將低含量之材料塗覆為塗層保持由線之芯的材料定義的特徵。另一方面，塗層給予線表面特定特徵，諸如相對於環境之惰性、抗腐蝕性、改良的接合性等。舉例而言，對於直徑為18 µm之線，塗層之厚度在20 nm至120 nm之範圍內。對於具有25 µm之直徑的線，塗層可具有(例如)在30 nm至150 nm範圍內之厚度。 在一實施例中，塗層可由貴金屬元素製成。塗層可為該等貴金屬元素中之一者的單層。在另一實施例中，塗層可為由多個疊加鄰近子層組成之多層，其中各子層由不同貴金屬元素製成。用於沈積該等貴金屬元素於芯上之常用技術為鍍覆，諸如電鍍及無電極電鍍；自氣相沈積材料，諸如濺鍍、離子電鍍、真空蒸發及物理氣相沈積；及自熔融物沈積材料。 在一實施例中，本發明之銀合金銅線或其芯之特徵在於以下固有特性中之至少一者(參見如下文所述之「測試方法A」)： (i)以縱向方向(線芯之縱向方向)量測，平均線粒度(平均粒度)低於4.0 µm，例如在2 µm至3 µm之範圍內， (ii)線芯之以縱向方向量測之平均粒度對直徑的比率在0.05至0.25、較佳地0.1至0.20之範圍內， (iii)以縱向方向量測，芯之平均粒度之標準差(RSD)對平均粒度的比率低於0.3，例如在0.1至0.2之範圍內。 在本文中對於線芯使用術語「固有特性」。固有特性意謂線芯自身具有之特性(與其他因素無關)。相對於固有特性之非固有特性視線芯與其他因素(如所採用之量測方法及/或量測條件)之關係而定。 在另一態樣中，本發明亦關於用於製造上文所揭示之其實施例中的任一者中銀合金銅線之方法。該方法包含至少以下步驟： (1)提供前驅體物品，其由以下組成： (a)呈0.3重量%至0.7重量%、較佳地0.5重量%之量的銀， (b)呈在99.25重量%至99.7重量%、較佳地99.45重量%至99.5重量%或甚至更佳地99.49重量%至99.5重量%範圍內之量的銅，以及 (c)0 wt.-ppm至500 wt.-ppm、較佳地0 wt.-ppm至100 wt.-ppm之另外組分， 其中所有以重量%及wt.-ppm為單位之量係按前驅體物品之總重量計， (2)拉長前驅體物品以形成線前驅體，直至獲得線芯之所需最終直徑；以及 (3)最終，在完成方法步驟(2)後，在介於600℃至680℃範圍內之烘箱設定溫度下，對所獲得之線前驅體進行帶材退火持續在0.1秒至3秒範圍內之暴露時間以形成銀合金銅線。 在本文中使用術語「帶材退火(strand annealing)」。其為允許以高再現性快速生產線的連續方法。帶材退火意謂動態地進行退火，此時待退火之伸長線前驅體物品或線前驅體經移動穿過退火烘箱且在已離開退火烘箱後纏繞於卷軸上。 在本文中使用術語「烘箱設定溫度」。其意謂退火烘箱之溫度控制器中所固定之溫度。通常在管狀退火烘箱中進行帶材退火。 本發明區分前驅體物品、線前驅體及銀合金銅線。術語「前驅體物品」用於尚未達到線芯之所需最終直徑之彼等線前階段，而術語「線前驅體」用於在所需最終直徑下之線前階段。在完成方法步驟(3)後，亦即在對在所需最終直徑下之線前驅體進行最終帶材退火後，獲得本發明意義上之銀合金銅線。 可藉由使銅與所需含量之銀合金化/摻雜獲得如方法步驟(1)中提供之前驅體物品。可藉由熟習金屬合金技術者已知之習知方法，例如藉由使銅與銀以所需比率熔融在一起製備銅合金自身。在此情況下，有可能利用母合金。可例如利用感應爐進行熔融方法，且有利的是在真空下或在惰性氣體氛圍下操作。所用材料可具有例如99.99重量%及高於99.99重量%之純度級。可冷卻如此產生之熔融物以形成基於銅之前驅體物品的均質件。通常，該前驅體物品呈具有(例如)2 mm至25 mm之直徑及(例如)5 m至100 m之長度的桿形式。可藉由將該銅合金熔融物澆鑄於室溫之合適模具中，隨後冷卻及固化製造該桿。 若如本發明之第一態樣之部分實施例所揭示，呈單層或多層形式之塗層存在於銀合金銅線之芯上，則較佳將此塗層塗覆至線前驅體物品上，該物品可能尚未經伸長，尚未經最終伸長或甚至充分經伸長至所需最終直徑。技術人員知道如何計算前驅體物品上之該塗層的厚度以獲得呈線之實施例所揭示之厚度的塗層，亦即在伸長具有塗層之前驅體物品以形成線前驅體之後。如上文已揭示，用於在銅合金表面上形成根據實施例之材料的塗層的眾多技術為已知的。較佳技術為鍍覆，諸如電鍍及無電極電鍍；自氣相沈積材料，諸如濺鍍、離子電鍍、真空蒸發及物理氣相沈積；及自熔融物沈積材料。 為使呈單層或多層之金屬塗層疊加至如本發明之第一態樣的部分實施例揭示之線芯上，有利的是當達到前驅體物品之所需直徑時中斷方法步驟(2)。該直徑可在(例如)80 µm至200 µm之範圍內。隨後可(例如)藉由一或多種電鍍方法步驟塗覆單層或多層金屬塗層。其後持續方法步驟(2)直至獲得線芯之所需最終直徑。 在方法步驟(2)中，伸長前驅體物品以形成線前驅體，直至獲得線芯之所需最終直徑。伸長前驅體物品以形成線前驅體之技術為已知的且顯得適用於本發明之情形。較佳技術為輥軋、型鍛、模拉伸或類似者，其中模拉伸尤佳。在後一情況中，在數個方法步驟中拉伸前驅體物品直至達到線芯之所需及最終直徑。 線芯之所需及最終直徑可在8 µm至80 µm之範圍內，或較佳在12 µm至55 µm之範圍內。熟習此項技術者熟知該線模拉伸方法。可採用習知碳化鎢及金剛石拉伸模，且可採用習知拉伸潤滑劑以支持拉伸。 較佳地步驟(2)不包括中間體退火之任何子步驟。 在方法步驟(3)中，最終對完成方法步驟(2)後所獲得之經伸長線前驅體進行帶材退火。在介於(例如)600℃至680℃範圍內之烘箱設定溫度下進行最終帶材退火持續0.1秒至3秒之暴露時間，或在一較佳實施例中，610℃至650℃持續0.1秒至1.5秒。在一例示性實施例中，可在630℃之烘箱設定溫度下持續0.85秒之暴露時間進行最終帶材退火。 通常藉由以指定退火速度將伸長線前驅體拉伸穿過習知退火烘箱(通常呈具有指定長度及限定溫度分佈之圓柱管形式)來進行最終帶材退火，該速度經選擇介於例如10公尺/分鐘至60公尺/分鐘之範圍內。如此做可限定及設定退火時間/烘箱溫度參數。 在一較佳實施例中，在水中淬火最終經帶材退火之銀合金銅線，該水在一實施例中可含有一或多種添加劑，例如0.01體積%至0.07體積%之添加劑。在水中淬火意謂(例如)藉由浸漬或滴注，立即或快速(亦即在0.2秒至0.6秒內)使最終經帶材退火之銀合金銅線自其在方法步驟(3)中經歷之溫度冷卻至室溫。 可在惰性或還原氛圍中進行方法步驟(3)之最終帶材退火。眾多類型之惰性氛圍以及還原氛圍為此項技術中已知的且用於淨化退火烘箱。在已知惰性氛圍中，氮氣或氬氣為較佳的。在已知還原氛圍中，氫氣為較佳實例。另一較佳還原氛圍為氫氣及氮氣之混合物。較佳氫氣及氮氣之混合物為90 vol.-%至98 vol.-%之氮氣及相應地2 vol.-%至10 vol.-%之氫氣，其中總vol.-%為100 vol.-%。較佳氮氣/氫氣之混合物等於93/7、95/5及97/3 vol.-%/vol.-%，各者按混合物之總體積計。若銀合金銅線表面之某些部分對由空氣之氧氣所致之氧化具有敏感性，則尤佳在退火中施加還原氛圍。用該等類型之惰性或還原氣體淨化較佳在處於10 min-1
至125 min-1
範圍內、更佳處於15 min-1
至90 min-1
範圍內、最佳處於20 min-1
至50 min-1
範圍內之氣體交換速率(=氣體流動速率[公升/分鐘]:烘箱內體積[公升])下進行。 咸信前驅體物品材料之組成(與成品銀合金銅線芯之組成相同)與在方法步驟(3)期間主要退火參數之獨特組合對獲得呈現上文所揭示固有特性中之至少一者的本發明之線為至關重要的。最終帶材退火步驟之溫度/時間條件允許達成或調節銀合金銅線芯之固有特性。與裸銅線相比本發明之銀合金銅線的較好總體效能為其組成與最終帶材退火條件之結果；兩個特徵一起產生表現為固有特性(i)至(iii)的特定顆粒結構。該特定顆粒結構造成良好效能參數。顆粒結構不同於裸銅線之顆粒結構，尤其在於較小平均粒度及較小粒度分佈。 在完成方法步驟(3)後，本發明之銀合金銅線為成品。為了完全得益於其特性，有利的是或者立刻使其用於線接合應用，亦即不經遲緩，舉例而言，在完成方法步驟(3)後不超過其10天空閒時間內。或者，為了保持銀合金銅線之寬線接合製程窗特性且為了防止其受到氧化或其他化學侵蝕，通常在完成方法步驟(3)之後立即將成品線纏繞及真空密封，亦即不經延遲，舉例而言，在完成方法步驟(3)後之＜ 1至5小時內，且隨後儲存以供進一步用作接線。儲存於真空密封條件下不應超出6個月。在打開真空密封後，應在不超過10天內將銀合金銅線用於線接合。 較佳的是，在無塵室條件(US FED STD 209E無塵室標準，1k標準)下進行所有方法步驟(1)至(3)以及纏繞及真空密封。 本發明之第三態樣為可藉由前文揭示的根據本發明之第二態樣或其一實施例的方法獲得的銀合金銅線。已發現該銀合金銅線相當適合用作線接合應用中之接線。線接合技術為技術人員熟知的。在線接合過程中，典型的是形成球接合(第1接合)及縫合(第2接合，楔形接合)。在形成接合期間施加特定力(通常以公克為單位量測)，其由施加擦洗幅度(通常以µm為單位量測)來支持或由施加超音波能量(通常以mA為單位量測)之來支持。在線接合製程中施加力上限與下限間之差值與施加擦洗幅度上限與下限間之差值的數學乘積或施加力上限與下限間之差值與施加超音波能量上限與下限間之差值的數學乘積定義線接合製程窗：( 施加力上限 - 施加力下限 ) · ( 施加擦洗幅度上限 - 施加擦洗幅度下限 )= 線接合製程窗。
或( 施加力上限 - 施加力下限 ) · ( 施加超音波能量上限 - 施加超音波能量下限 )= 線接合製程窗。
線接合製程窗定義力/擦洗幅度組合或力/超音波能量組合之面積，其允許形成符合規格之線接合，亦即其通過習知測試，僅舉幾例如習知拉伸測試、球剪切測試及球拉伸測試。 換言之，第1接合(球接合)製程窗面積為接合中使用之力的上限與下限間差值與施加擦洗幅度上限與下限間差值的乘積或接合中使用之力的上限與下限間差值與施加超音波能量上限與下限間差值的乘積，其中所得接合必須符合特定球剪切測試規格，例如0.0085公克/平方微米之球剪切力，在接合墊上無不黏等，而第2接合(縫合)製程窗面積為接合中使用之力的上限與下限間差值與施加擦洗幅度上限與下限間差值的乘積或接合中使用之力的上限與下限間差值與施加超音波能量上限與下限間差值的乘積，其中所得接合必須符合特定拉伸測試規格，例如2.5公克之拉力，在導線上無不黏等。 對於工業應用，出於線接合製程穩固性之原因，期望具有寬線接合製程窗(以g為單位之力與以µm為單位之擦洗幅度比較或以g為單位之力與以mA為單位之超音波能量比較)。本發明之線呈現相當寬之線接合製程窗。 以下非限制性實例說明本發明。此等實例用於本發明之例示性闡明，且無論如何並不意欲限制本發明之範疇或申請專利範圍。實例 測試方法 A 至 D
在T = 20℃且相對濕度RH = 50%下進行所有測試及量測。 A. 線性截取方法 首先利用冷鑲嵌環氧樹脂罐封線，且隨後藉由標準金相技術拋光(橫截面)。使用多製備型半自動拋光器用低力及最佳速度研磨及拋光樣品，在樣品表面上具有最小形變應變。最終，使用氯化鐵化學蝕刻經拋光樣品以展現晶界。根據ASTM E112-12標準使用線性截取方法在具有1000放大率之光學顯微鏡下量測粒度。 B. 球形狀 利用EFO (電子滅焰)火焰(EFO電流50 mA，EFO時間120 µs，在95/5 vol.-%/vol.-%之氮氣/氫氣氛圍下)形成FAB (無空氣球)。所形成FAB自預定高度(203.2 µm之頂端)及速度(6.4 µm/sec之接觸速度)下降至接合墊。當接觸接合墊時，實行一組經定義之接合參數(100 g之接合力，95 mA之超音波能量及15 ms之接合時間)以使FAB變形且形成接合球。在形成球後，使毛細管上升至預定高度(152.4 µm之扭接高度及254 µm之迴路高度)以形成迴路。在形成迴路後，使毛細管下降至導線以形成縫合。在形成縫合後，使毛細管上升且線夾閉合以切割線以形成預定尾部長度(254 µm之尾部長度延伸)。對於每一樣品，利用具有1000之放大率的顯微鏡光學檢測五個接合線。評定：+圓形，0可接受，-花哨的 C. 偏心球(OCB) 應用與方法B中所描述之相同的方法，但測定球之歸心性而非檢測球之圓度。對於每一樣品，光學檢測五個接合線。評定：+中心，0可接受地偏心，-偏心 D. 耐腐蝕性： 連續澆鑄8 mm桿分離至10 mm長度且在85℃下浸沒於鹽溶液中持續4天，利用去離子化(DI)水且隨後利用丙酮洗滌。鹽溶液含有20重量% NaCl溶解於DI水中。在較低倍率顯微鏡(立體顯微鏡-SZX16)下以10至100×放大率觀測到桿之表面脫色。自原始銅轉變上升至暗黑色之桿表面指示重度裂隙腐蝕。在暗黑色表面上之SEM-EDX揭示氯、氧及銅之峰值。 評定： -，100%澆鑄桿自原始銅轉變上升至暗黑色，重度裂隙腐蝕之指示 0，＜70%澆鑄桿自原始銅轉變上升至黑色，裂隙腐蝕之指示 +，＜40%澆鑄桿自原始銅轉變上升至黑色，輕度裂隙腐蝕之指示 ++，＜10%澆鑄桿自原始銅轉變上升至暗黑色，極少顯著性或不存在裂隙腐蝕之指示實例
在真空烘箱中在約1200℃下使至少99.99%純度(「4N」)之一定量的銅(Cu)及合金化元素(銀(Ag)或鎳(Ni)或金(Au)或鉑(Pt)或鈀(Pd))在各情況下熔融於坩堝中。隨後自熔融物連續澆鑄呈8 mm桿形式之線芯前驅體物品。隨後在若干拉伸步驟中拉伸線芯前驅體物品以形成具有18 ± 0.5 µm之指定直徑的線芯前驅體。線芯之橫斷面基本上為圓形形狀。 在630℃之烘箱設定溫度下對18 µm線芯前驅體進行最終帶材退火持續0.85秒之暴露時間，隨後在含有0.05 vol.-%界面活性劑之水中淬火如此獲得之線。利用95 vol.-%氮氣:5 vol.-%氫氣淨化氣體混合物進行帶材退火。最後，經退火線纏繞於清潔的陽極化(經鍍覆)鋁線軸上，經真空裝填及儲存。 在一替代程序中，在550℃之烘箱設定溫度下對18 µm線芯前驅體進行最終帶材退火持續0.85秒之暴露時間。所有其他條件保持相同。 在另一替代程序中，在700℃之烘箱設定溫度下對18 µm線芯前驅體進行最終帶材退火持續0.85秒之曝露時間。所有其他條件保持相同。 借助於此等程序，製造合金化銅線之數個樣品1至9 (根據本發明及比較)及4N純度(參考)之參考銅線。 表1展示根據本發明之樣品1至9不同線的組成。
表1：銅合金1至9之化學組成 表2展示藉由接合至Al-0.5重量% Cu接合墊且根據上文所揭示之測試方法測試的線樣品1至9獲得的特定測試結果。所有測試使用18 µm線進行。
表2：藉由線樣品1至9獲得之特定測試結果In a first aspect, the invention relates to a silver alloy copper wire comprising a core or even a core (hereinafter also referred to simply as "core"), the core itself consisting of: (a) 0.3 Silver in an amount of % by weight (% by weight) to 0.7% by weight, preferably 0.5% by weight, (b) is from 99.25% to 99.7% by weight, preferably 99.45 wt% to 99.5% by weight or even more preferably in an amount ranging from 99.49 wt% to 99.5% by weight, and (c) 0 wt.-ppm (weight-ppm, weight ppm) to 500 wt.-ppm, Preferably, from 0 wt.-ppm to 100 wt.-ppm, additional components (components other than silver and copper), all in weight percent and wt.-ppm, based on the total weight of the core. The following table summarizes various embodiments of the composition of a silver alloy copper core: The silver alloy copper wire is preferably a wire for bonding in microelectronics. The silver alloy copper wire is preferably a one-piece article. Numerous shapes are known and appear to be suitable for use in the silver alloy copper wire of the present invention. For the purposes of the present invention, the term "wiring" encompasses cross-sections of all shapes and all common wire diameters, but wires having a circular cross-section and a thin diameter are preferred. The average cross section is in the range of, for example, 50 μm 2 to 5024 μm 2 or preferably 110 μm 2 to 2400 μm 2 ; therefore, in the case of a preferred circular cross section, the average diameter is, for example, 8 μm to 80 μm or preferably 12 μm to 55 μm. The average diameter or the diameter of the wire or core can be obtained by "sizing method". The physical weight of the silver alloy copper wire of defined length is determined according to this method. Based on this weight, the diameter of the wire or core is calculated using the line material density. The diameter is calculated as the arithmetic mean of the five measurements on the five cuts of a particular line. Consistent with the foregoing, the ratio of the cores previously disclosed includes (a) silver and (b) copper. However, the core of the silver alloy copper wire of the present invention may comprise (c) additional components in a total amount of from 0 wt.-ppm to 500 wt.-ppm, preferably from 0 wt.-ppm to 100 wt.-ppm. . In this context, additional components, also commonly referred to as "inevitable impurities", are derived from impurities present in the raw materials used or from small amounts of chemical constituents and/or compounds derived from the wire making process, ie, The presence of additional components of the type (c) may, for example, be derived from impurities present in silver and/or copper. Examples of such additional components are: Au, P, Ni, Pd, Fe, Si, Mn, Cr, Ce, Mg, La, Al, B, Zr, Ti, S, and the like. A low total amount of 0 wt.-ppm to 500 wt.-ppm or even 0 wt.-ppm to 100 wt.-ppm of the additional component (c) ensures good reproducibility of the line characteristics. The additional component (c) present in the core is usually not added separately. In one embodiment, the core of the silver alloy copper wire of the present invention comprises an additional component (c) of less than 15 wt.-ppm in an amount of each of: Au, P, Ni, Pd, Fe, Si, Mn , Cr, Ce, Mg, La, Al, B, Zr, Ti, S. The core of a silver alloy copper wire in this context is defined as a homogeneous region of the bulk material. Since any bulk material always has a surface area that exhibits different properties to some extent, the characteristics of the core of the wire are understood to be the characteristics of the homogeneous region of the bulk material. The surface of the bulk material region may differ in morphology, composition (e.g., chlorine and/or oxygen content), and other characteristics. The surface may be the outer surface of the core; in this embodiment, the silver alloy copper wire of the present invention is composed of a core. In an alternative, the surface can be an interfacial region between the core and the coating superimposed on the core. The term "superposition" in the context of the present invention is used to describe the relative position of a first article (e.g., a core) relative to a second article (e.g., a coating). "Overlay" is characterized by an additional item such as an intermediate layer that may (but need not) be disposed between the first item and the second item. Preferably, the second article is at least partially superimposed on the first article, for example up to at least 30%, 50%, 70% or at least 90%, each relative to the total surface of the first article. Optimally, the second item is completely superimposed on the first item. The term "intermediate layer" in the context of the present invention refers to the region of the silver alloy copper wire between its core and the coating superimposed thereon. In this region, there is a combination of materials for both the core and the coating. In the context of the present invention, the term "thickness" is used to define the dimension of a layer in a direction perpendicular to the longitudinal axis of the core which is at least partially superimposed on the surface of the core. In an embodiment, the core has a surface in which the coating is superimposed on the surface of the core. In one embodiment, the mass of the coating does not exceed 5% by weight, preferably 2% by weight or less, and the total mass of each of the coatings relative to the core. When a coating is present, it typically has a minimum mass of 0.1% by weight or greater, or 0.5% by weight or greater than 0.5% by weight, with respect to the total mass of the core. Applying a low level of material to the coating maintains the characteristics defined by the material of the core of the wire. On the other hand, the coating imparts specific features to the surface of the wire, such as inertness to the environment, corrosion resistance, improved bondability, and the like. For example, for a wire having a diameter of 18 μm, the thickness of the coating is in the range of 20 nm to 120 nm. For wires having a diameter of 25 μm, the coating can have a thickness, for example, in the range of 30 nm to 150 nm. In an embodiment, the coating may be made of a precious metal element. The coating can be a single layer of one of the precious metal elements. In another embodiment, the coating can be a plurality of layers consisting of a plurality of superposed adjacent sub-layers, wherein each sub-layer is made of a different precious metal element. Common techniques for depositing such precious metal elements on the core are plating, such as electroplating and electroless plating; self-vapor deposition materials such as sputtering, ion plating, vacuum evaporation, and physical vapor deposition; and deposition from the melt. material. In one embodiment, the silver alloy copper wire of the present invention or its core is characterized by at least one of the following inherent characteristics (see "Test Method A" as described below): (i) in the longitudinal direction (core) Measurement in the longitudinal direction), the average line size (average particle size) is less than 4.0 μm, for example in the range of 2 μm to 3 μm, and (ii) the ratio of the average particle size to the diameter of the core measured in the longitudinal direction is 0.05. To a range of 0.25, preferably 0.1 to 0.20, (iii) measured in the machine direction, the ratio of the standard deviation of the average particle size (RSD) of the core to the average particle size is less than 0.3, for example in the range of 0.1 to 0.2. The term "inherent property" is used herein for the core. Inherent characteristics mean the characteristics of the core itself (regardless of other factors). The relationship between the line of sight core and other factors (such as the measurement method and/or measurement conditions employed) relative to the intrinsic characteristics of the inherent characteristics. In another aspect, the invention is also directed to a method for making a silver alloy copper wire in any of the embodiments disclosed above. The method comprises at least the following steps: (1) providing a precursor article consisting of: (a) silver in an amount of from 0.3% by weight to 0.7% by weight, preferably 0.5% by weight, (b) in a weight of 99.25 Copper in an amount ranging from % to 99.7% by weight, preferably from 99.45% to 99.5% by weight or even more preferably from 99.49% to 99.5% by weight, and (c) from 0 wt.-ppm to 500 wt.-ppm , preferably from 0 wt.-ppm to 100 wt.-ppm, wherein all amounts in wt% and wt.-ppm are based on the total weight of the precursor article, (2) elongated precursor Body article to form a wire precursor until the desired final diameter of the core is obtained; and (3) finally, after completing method step (2), at an oven set temperature in the range of 600 ° C to 680 ° C, The obtained line precursor was subjected to strip annealing for an exposure time in the range of 0.1 second to 3 seconds to form a silver alloy copper wire. The term "strand annealing" is used herein. It is a continuous method that allows rapid production lines with high reproducibility. Strip annealing means that the annealing is performed dynamically, at which point the elongated wire precursor article or wire precursor to be annealed is moved through the annealing oven and wrapped around the reel after leaving the annealing oven. The term "oven set temperature" is used herein. It means the temperature fixed in the temperature controller of the annealing oven. Strip annealing is typically performed in a tubular annealing oven. The invention distinguishes precursor articles, wire precursors and silver alloy copper wires. The term "precursor article" is used in the pre-line phase of the desired final diameter of the core, and the term "line precursor" is used in the pre-line phase at the desired final diameter. After completion of method step (3), i.e., after final strip annealing of the line precursor at the desired final diameter, a silver alloy copper wire in the sense of the present invention is obtained. The precursor article provided in method step (1) can be obtained by alloying/doping copper with a desired amount of silver. The copper alloy itself can be prepared by conventional methods known to those skilled in the art of metal alloys, for example by melting copper and silver together at a desired ratio. In this case, it is possible to utilize the master alloy. The melting process can be carried out, for example, using an induction furnace, and is advantageously operated under vacuum or under an inert gas atmosphere. The material used may have a purity level of, for example, 99.99% by weight and more than 99.99% by weight. The melt thus produced can be cooled to form a homogeneous piece based on the copper precursor article. Typically, the precursor article is in the form of a rod having a diameter of, for example, 2 mm to 25 mm and a length of, for example, 5 m to 100 m. The rod can be made by casting the copper alloy melt in a suitable mold at room temperature, followed by cooling and solidification. If, as disclosed in some embodiments of the first aspect of the present invention, a coating in the form of a single layer or a plurality of layers is present on the core of a silver alloy copper wire, it is preferred to apply the coating to the wire precursor article. The article may not have been stretched, has not been finally stretched or even fully elongated to the desired final diameter. The skilled person knows how to calculate the thickness of the coating on the precursor article to obtain a coating of the thickness disclosed in the embodiment of the wire, i.e., after elongating the body article prior to coating to form a wire precursor. As has been disclosed above, numerous techniques for forming a coating of a material according to an embodiment on a surface of a copper alloy are known. Preferred techniques are plating, such as electroplating and electroless plating; materials deposited from vapor phase, such as sputtering, ion plating, vacuum evaporation, and physical vapor deposition; and materials deposited from the melt. In order to superimpose a single or multiple layer metal coating onto a core as disclosed in the partial embodiment of the first aspect of the invention, it is advantageous to interrupt the method step (2) when the desired diameter of the precursor article is reached. . This diameter can be in the range of, for example, 80 μm to 200 μm. The single or multiple layer metal coating can then be applied, for example, by one or more plating process steps. Thereafter, method step (2) is continued until the desired final diameter of the core is obtained. In method step (2), the precursor article is elongated to form a wire precursor until the desired final diameter of the core is obtained. The technique of elongating the precursor article to form a wire precursor is known and appears to be suitable for use in the context of the present invention. The preferred technique is roll, swage, die drawing or the like, with die stretching being preferred. In the latter case, the precursor article is stretched in several method steps until the desired and final diameter of the core is reached. The desired and final diameter of the core may range from 8 μm to 80 μm, or preferably from 12 μm to 55 μm. The wire drawing stretching method is well known to those skilled in the art. Conventional tungsten carbide and diamond tensile dies can be used, and conventional stretching lubricants can be used to support stretching. Preferably step (2) does not include any substeps of the intermediate annealing. In method step (3), the stretched-line precursor obtained after completion of method step (2) is finally subjected to strip annealing. Final strip annealing is performed at an oven set temperature in the range of, for example, 600 ° C to 680 ° C for an exposure time of 0.1 second to 3 seconds, or in a preferred embodiment, 610 ° C to 650 ° C for 0.1 second Up to 1.5 seconds. In an exemplary embodiment, the final strip anneal can be performed at an oven set temperature of 630 ° C for an exposure time of 0.85 seconds. The final strip annealing is typically performed by stretching the elongated wire precursor through a conventional annealing oven (typically in the form of a cylindrical tube having a specified length and a defined temperature profile) at a specified annealing rate, which is selected, for example, between 10 Within the range of meters/minute to 60 meters/minute. This can be done to define and set the annealing time/oven temperature parameters. In a preferred embodiment, the strip-annealed silver alloy copper wire is quenched in water, which in one embodiment may contain one or more additives, such as from 0.01% to 0.07% by volume of the additive. Quenching in water means that, for example, by impregnation or dripping, the final strip annealed silver alloy copper wire is subjected to the method step (3) either immediately or quickly (ie within 0.2 seconds to 0.6 seconds). The temperature was cooled to room temperature. The final strip annealing of method step (3) can be carried out in an inert or reducing atmosphere. Numerous types of inert atmospheres and reducing atmospheres are known in the art and are used in purification annealing ovens. Nitrogen or argon is preferred in known inert atmospheres. Hydrogen is a preferred example in a known reducing atmosphere. Another preferred reducing atmosphere is a mixture of hydrogen and nitrogen. Preferably, the mixture of hydrogen and nitrogen is from 90 vol.-% to 98 vol.-% of nitrogen and correspondingly from 2 vol.-% to 10 vol.-% of hydrogen, wherein the total vol.-% is 100 vol.-% . Preferably, the nitrogen/hydrogen mixture is equal to 93/7, 95/5 and 97/3 vol.-%/vol.-%, each based on the total volume of the mixture. If some portion of the surface of the silver alloy copper wire is sensitive to oxidation by oxygen of the air, it is preferred to apply a reducing atmosphere during annealing. Purification with these types of inert or reducing gases is preferably in the range of 10 min -1 to 125 min -1 , more preferably in the range of 15 min -1 to 90 min -1 , optimally in the range of 20 min -1 to 50 The gas exchange rate in the range of min -1 (= gas flow rate [liters per minute]: volume in the oven [liters]). The unique combination of the composition of the precursor material material (same composition of the finished silver alloy copper wire core) and the primary annealing parameter during method step (3) is obtained to obtain at least one of the inherent characteristics disclosed above. The line of invention is crucial. The temperature/time conditions of the final strip annealing step allow for the achievement or adjustment of the inherent properties of the silver alloy copper core. The better overall performance of the silver alloy copper wire of the present invention compared to the bare copper wire is the result of its composition and the final strip annealing conditions; the two features together produce a specific particle structure that exhibits intrinsic properties (i) through (iii) . This particular particle structure results in good performance parameters. The particle structure is different from the grain structure of the bare copper wire, especially in the smaller average particle size and smaller particle size distribution. After completion of method step (3), the silver alloy copper wire of the present invention is a finished product. In order to fully benefit from its characteristics, it is advantageous or immediately to use it for wire bonding applications, ie without delay, for example, no more than 10 days of idle time after completion of method step (3). Alternatively, in order to maintain the wide wire bonding process window characteristics of the silver alloy copper wire and to prevent oxidation or other chemical attack, the finished wire is usually wound and vacuum sealed immediately after the completion of the method step (3), that is, without delay. For example, within <1 to 5 hours after completion of method step (3), and then stored for further use as a wire. Store under vacuum tight conditions should not exceed 6 months. After the vacuum seal is opened, the silver alloy copper wire should be used for wire bonding in less than 10 days. Preferably, all process steps (1) through (3) and winding and vacuum sealing are carried out in clean room conditions (US FED STD 209E clean room standard, 1k standard). A third aspect of the invention is a silver alloy copper wire obtainable by the method according to the second aspect of the invention or an embodiment thereof as disclosed hereinbefore. This silver alloy copper wire has been found to be quite suitable for use in wire bonding applications. Wire bonding techniques are well known to the skilled person. In the wire bonding process, ball bonding (first bonding) and stitching (second bonding, wedge bonding) are typically formed. Applying a specific force (usually measured in grams) during the formation of the joint, which is supported by the application of the scrubbing amplitude (usually measured in μm) or by the application of ultrasonic energy (usually measured in mA) stand by. The difference between the difference between the upper and lower limits of the applied force in the in-line bonding process and the difference between the upper and lower limits of the upper and lower limits of the applied scrubbing amplitude and the difference between the upper and lower limits of the applied ultrasonic energy The mathematical product defines the wire bonding process window: ( Upper force application - Lower force applied ) · ( Applied scrubbing upper limit - Applied scrubbing amplitude lower limit ) = Wire bonding process window. Or (force limit is applied - the lower limit of force is applied) · (applying ultrasonic energy limit - applying ultrasonic energy limit) = wire bonding process window. The wire bonding process window defines the area of force/scouring amplitude combination or force/ultrasonic energy combination that allows for the formation of wire bonds that conform to specifications, ie, by conventional testing, such as conventional tensile testing, ball shearing Test and ball tensile test. In other words, the first joint (ball joint) process window area is the product of the difference between the upper limit and the lower limit of the force used in the joint and the difference between the upper limit and the lower limit of the applied scrub range or the difference between the upper and lower limits of the force used in the joint. The product of the difference between the upper and lower limits of the applied ultrasonic energy, where the resulting joint must conform to a specific ball shear test specification, such as a ball shear force of 0.0085 gram per square micrometer, without sticking on the bond pad, etc., and the second bond The (sewed) process window area is the product of the difference between the upper and lower limits of the force used in the joint and the difference between the upper and lower limits of the applied scrubbing amplitude or the difference between the upper and lower limits of the force used in the joint and the upper limit of the applied ultrasonic energy. The product of the difference from the lower limit, where the resulting joint must conform to a specific tensile test specification, such as a pull force of 2.5 grams, and no stickiness on the wire. For industrial applications, for reasons of wire bonding process stability, it is desirable to have a wide wire bonding process window (force in g versus scrub rate in μm or force in g and in mA Ultrasonic energy comparison). The wire of the present invention presents a relatively wide line of bonding process windows. The following non-limiting examples illustrate the invention. The examples are intended to be illustrative of the invention and are not intended to limit the scope of the invention or the scope of the invention. Example Test Methods A to D All tests and measurements were performed at T = 20 ° C and relative humidity RH = 50%. A. The linear intercept method first seals the wire with a cold inlaid epoxy resin tank and is then polished (cross section) by standard metallographic techniques. The multi-prepared semi-automatic polisher is used to grind and polish the sample with low force and optimum speed with minimal strain on the sample surface. Finally, the polished sample was chemically etched using ferric chloride to reveal grain boundaries. The particle size was measured under an optical microscope with a magnification of 1000 using a linear intercept method according to the ASTM E112-12 standard. B. Ball shape Using an EFO (Electron Flame Extinguishing) flame (EFO current 50 mA, EFO time 120 μs, under a 95/5 vol.-%/vol.-% nitrogen/hydrogen atmosphere) to form FAB (no air ball) . The formed FAB was lowered from the predetermined height (top of 203.2 μm) and the speed (contact speed of 6.4 μm/sec) to the bonding pad. When contacting the bond pads, a defined set of bonding parameters (100 g of bonding force, 95 mA of ultrasonic energy and 15 ms of bonding time) were performed to deform the FAB and form a splice ball. After the ball is formed, the capillary is raised to a predetermined height (a twist height of 152.4 μm and a loop height of 254 μm) to form a loop. After the loop is formed, the capillary is lowered to the wire to form a stitch. After the stitching is formed, the capillary is raised and the clip is closed to cut the line to form a predetermined tail length (a tail length extension of 254 μm). For each sample, five bonding wires were optically detected using a microscope having a magnification of 1000. Evaluation: + circle, 0 acceptable, - fancy C. Eccentric ball (OCB) The same method as described in Method B was applied, but the ball centering was determined instead of the roundness of the ball. Five bond wires were optically detected for each sample. Evaluation: + center, 0 acceptable eccentricity, - eccentricity D. Corrosion resistance: Continuous casting 8 mm rod separated to 10 mm length and immersed in salt solution at 85 ° C for 4 days, using deionization (DI) The water was then washed with acetone. The salt solution contained 20% by weight of NaCl dissolved in DI water. Decolorization of the surface of the rod was observed at a magnification of 10 to 100 x under a low magnification microscope (stereo microscope - SZX16). The rise from the original copper transition to the dark black rod surface indicates severe crevice corrosion. SEM-EDX on a dark black surface reveals peaks of chlorine, oxygen and copper. Rating: -, 100% cast rods rise from raw copper to dark black, indication of severe crevice corrosion 0, <70% cast rods rise from original copper to black, indication of crevice corrosion +, <40% cast rods from original The copper transition rises to black, the indication of mild crevice corrosion ++, <10% of the cast rod rises from the original copper transition to dark black, with little or no crevice corrosion indication example in a vacuum oven at about 1200 ° C Quantitative copper (Cu) and alloying elements (silver (Ag) or nickel (Ni) or gold (Au) or platinum (Pt) or palladium (Pd)) in at least 99.99% purity ("4N") in each case Melt in the sputum. A core precursor article in the form of a rod of 8 mm is then continuously cast from the melt. The core precursor article is then stretched in several stretching steps to form a core precursor having a specified diameter of 18 ± 0.5 μm. The cross section of the core is substantially circular in shape. The final strip annealing of the 18 μm core precursor was carried out at an oven set temperature of 630 ° C for an exposure time of 0.85 seconds, followed by quenching the line thus obtained in water containing 0.05 vol.-% of the surfactant. Strip annealing was performed using 95 vol.-% nitrogen: 5 vol.-% hydrogen purge gas mixture. Finally, the annealed wire is wound onto a clean anodized (plated) aluminum spool and vacuum filled and stored. In an alternative procedure, a final strip anneal of the 18 μm core precursor was performed at an oven set temperature of 550 ° C for an exposure time of 0.85 seconds. All other conditions remain the same. In another alternative procedure, the 18 μm core precursor was subjected to final strip annealing at an oven set temperature of 700 ° C for an exposure time of 0.85 seconds. All other conditions remain the same. By means of these procedures, a number of samples 1 to 9 of the alloyed copper wire (according to the invention and comparison) and a reference copper wire of 4N purity (reference) were produced. Table 1 shows the composition of the different lines of samples 1 to 9 according to the present invention. Table 1: Chemical Composition of Copper Alloys 1 to 9 Table 2 shows the specific test results obtained by wire samples 1 to 9 tested by the test methods disclosed above by bonding to Al-0.5 wt% Cu bond pads. All tests were performed using a 18 μm line. Table 2: Specific test results obtained by line samples 1 to 9