200915524 九、發明說明 【發明所屬之技術領域】 本發明係有關於積體電路封裝的領域。詳言之，本發 明係有關於電路板與積體電路晶粒上的接觸墊（contact pad )之間的線接合包封。 【先前技術】 製造於矽晶圓基材上的積體電路藉由線接合而被電連 接至印刷電路板上。線接合是非常薄的電線一直徑約25 至40微米一其由接觸墊沿著晶圓基材的側邊延伸至印刷 電路板（PCB )上的接點。爲了保護及強化線接合，線接 合被密封在一被稱爲包封劑的環氧樹脂珠粒（bead )內。 從接觸墊到PCB的電線被作成比所需要的更長用以適應 介於PCB與接觸墊之間的間隙因爲熱膨脹，構件的屈曲 等等所產生的改變。這些比所需要的還長的電線很自然地 形成接觸墊與P C B之間的一個弧。該電線弧的頂端通常 是在接觸墊之上約3 00微米，但有些線接合會延伸得更高 。如其名稱讓人聯想到的，包封劑必需將整個電線的長$ 包封起來，所以包封劑珠粒將擴展至接觸墊之上5 00微米 至600微米。 製造於矽晶圓基材上的積體電路通常被稱爲一 ‘晶粒 (die )’。爲了說明書的目的，晶粒一詞將被用來指稱— 使用光刻技術（通常用於半導體製造中之蝕刻與沉積技術 )製造於晶圓基材上的積體電路。如果該晶粒純粹是一胃 -5- 200915524 子的微處理器的話，就不太需要保持包封劑珠粒尺寸的嚴 密控制。然而，如果該晶粒是一具有活性上表面之微機電 系統（MEMS )裝置的話，則讓該晶粒的活性表面與另一 表面緊鄰就是有必要或是所想要的。此情況適用於噴墨列 印頭。列印媒介對噴嘴陣列的接近程度會影響列印品質。 相同地，如果一清潔表面刮掃過噴嘴的話，則包封劑的珠 粒會妨礙該刮掃接觸。 另一個問題是因爲包封劑珠粒的側邊不是筆直的而發 生。一種通常用來沉積該包封劑的技術包含將包封劑從一 針頭直接擠到一排線接合上。包封劑的體積及在晶粒上的 放置並沒有很精確。該幫浦壓力的變化或該針頭的速度上 稍微不一致都會造成該珠粒之與該活性表面相接觸的一側 被相當地彎曲。該珠粒的該側邊不是筆直的時，它必需與 該活性表面上之任何活性部件適當地間隔開，用以寬裕地 容納擾亂（perturbation )。將電接點與該活性表面的活 性部分（例如，噴墨噴嘴）間隔開來會耗盡有價値的晶圓 資源並減少可從一片晶圓上製造出來的晶粒數目。 有鑑於噴墨列印頭的廣泛使用，本發明將特別以在此 領域上的應用爲例來加以描述。然而，一般人將可瞭解的 是’這純粹是舉例性的且本發明可同樣地應用到線接合至 一 PCB或其它支撐結構的積體電路上。 【發明內容】 依據第一態樣’本發明提供一種微處理器裝置，其包 -6- 200915524 含： 一支撐結構，其具有一晶片安裝區及一導體安裝區； 一噴墨列印頭1C，其被支撐在該晶片安裝區上，該 噴墨列印頭1C具有一與該晶片安裝區接觸的背面及一與 該背面相反之活性表面’該活性表面具有電接觸墊及一陣 列的噴墨噴嘴； 多個電導體，其至少部分地被支撐在該導體安裝區上 :及 一系列的線接合，其由該等電接觸墊延伸至多個被支 撐在該導體安裝區上的電導體；其中 該晶片安裝區相對於該導體安裝區被升高。 藉由將該晶片安裝區相對於該PCB的其它部分，或 至少連接至該線接合的PCB端的導體，升高，由該層形 成的弧的頂端更靠近該晶粒之活性表面。這可讓包封劑的 珠粒具有一相對於該活性表面而言較低的剖面。藉此低的 包封劑珠粒，該活性表面可被帶引更加緊鄰另一表面而不 相接觸。例如’在一列印頭1C上的噴嘴陣列可以離該紙 張路徑3 00微米至400微米。 較佳地，該晶片安裝區相對於該導體安裝區被升高超 過1 〇〇微米。較佳地，該支撐結構具有一級階介於該晶片 安裝區與該導體安裝區之間。 較佳地’該等多個導體被一排沿著最靠近該晶粒的邊 緣之接合墊倂入到該可撓曲的印刷電路板（撓性p c B )中 ，該等接合墊離晶粒上的接觸墊超過2公釐。 -7- 200915524 較佳地’該等線接合是用直徑小於40微米的電線形 成的並延伸於該晶粒之活性表面上方小於1 0 0微米處。 較佳地，該等線接合被塑性地變形使得它們延伸於該 晶粒之活性表面上方小於5 0微米處。 較佳地，該活性表面具有功能性元件，其與該晶粒上 的接觸墊相距小於2 6 0微米。在一特佳的形式中，該晶粒 爲一噴墨列印頭1C且該等功能性元件爲噴嘴，墨水經由 噴嘴被噴出。在一些實施例中，該支撐結構爲一液晶聚合 物（LCP )模製物。 較佳地，該等線接合被覆蓋在一包封劑的珠粒中，該 包封劑的珠粒延伸於該晶粒之活性表面上方小於200微米 處。 較佳地，該等線接合被覆蓋在一包封劑的珠粒中’該 包封劑的珠粒具有一經過剖面化的表面，它是平的’平行 於該活性表面且與其相距小於100微米。 較佳地，該等線接合被覆蓋在一包封劑的珠粒中’該 包封劑的珠粒具有一平的且相對於該活性表面傾斜之經過 剖面化的表面。 較佳地，該等線接合被覆蓋在一包封劑的珠粒中’該 包封劑是一環氧樹脂物質’其在未固化時是搖變性的（ thixotropic) 。 較佳地，該等線接合被覆蓋在—包封劑的珠粒中’該 包封劑是一環氧樹脂物質’其在未固化時具有大於700cp 的黏度。 -8- 200915524 在一特定的實施例中’該列印頭IC被安裝在一印表 機內使得在使用期間噴嘴離紙張路徑小於10 0微米。 依據第二態樣，本發明提供一種將介於一晶粒上的接 觸墊與一支撐結構上的導體之間的線接合剖面化作業的方 法，該方法包含的步驟爲： 用一線接合將晶粒上的接觸墊電連接至該支撐結構上 的導體，該線接合延伸成爲一從該接觸墊至該導體的弧； 推擠該線接合用以讓該弧塌陷並將該線接合塑性地變 形；及 釋放該線接合使得該塑性變形將該線接合保持在一較 平的剖面形狀。 該線接合的強度是相當小，在3至5克力的等級。然 而，申請人的硏究顯示該線接合結構堅固到足以承受來自 塑性變形之一定程度的加工硬化。該線接合的弧可在不犧 牲與PCB的電連接下被變形成爲一較平的剖面。 較佳地，該晶粒具有一活性表面其具有功能性元件， 接觸墊其被形成在該活性表面的一個邊緣上，該線接合具 有一小於40微米的直徑且該弧延伸在該晶粒之活性表面 上方大於100微米處。 較佳地，該等線接合被塑性地變形使得它們延伸於該 晶粒之活性表面上方小於5 0微米處。 較佳地’該線接合藉由與一刀片狀物嚙合而被推擠， 該刀片狀物具有一用來接觸該線接合之圓角化的邊緣區。 較佳地，該方法進一步包含的步驟爲： -9- 200915524 施用一包封劑的珠粒於該線接合上；及 移動一剖面化作業表面於該活性表面之上用以將該包 封劑的珠粒平坦化。 較佳地，該包封劑的珠粒具有一經過剖面化的表面， 它是平的，平行於該活性表面且與其相距小於1 00微米。 較佳地，該包封劑的珠粒具有一平的且相對於該活性 表面傾斜之經過剖面化的表面。 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 具有大於700cp的黏度。在一較佳的實施例中’該包封劑 是一環氧樹脂物質，其在未固化時是搖變性的（ thixotropic) 〇 較佳地，該方法進一步包含的步驟爲： 將該剖面化作業表面放置成與該活性表面相鄰並與其 間隔開，用以界定一間隙；及 將包封劑的珠粒施用到該等接觸墊上，使得該珠粒的 一側接觸該剖面化作業表面且該珠粒的一部分延伸至該間 隙內並到達該活性表面。 較佳地，該活性表面具有功能性元件’其與該晶粒上 的接觸墊相距小於260微米。在一特佳的形式中’該晶粒 爲一噴墨列印頭IC且該等功能性元件爲噴嘴，墨水經由 噴嘴被噴出。在一些實施例中’該列印頭1C被安裝在一 印表機內使得在使用期間噴嘴離紙張路徑小於100微米。 較佳地，該支撐結構，其具有一晶片安裝區及一導體 安裝區，該晶粒被支撐在該晶片安裝區上’及多個電導體 -10- 200915524 至少部分地被支撐在該導體安裝區上，其中該晶片安裝區 相對於該導體安裝區被升高。 較佳地，該晶片安裝區相對於該導體安裝區被升高超 過1 0 0微米。較佳地，該支撐結構具有一級階介於該晶片 安裝區與該導體安裝區之間。在一些實施例中，該等多個 導體被一排沿著最靠近該晶粒的邊緣之接合墊倂入到該可 撓曲的印刷電路板（撓性PCB )中，該等接合墊離晶粒上 的接觸墊超過2公釐。 較佳地，該支撐結構爲一液晶聚合物（LCP )模製物 〇 依據第三態樣，本發明提供一種將沿著安裝在一支撐 結構上的晶粒的邊緣延伸之包封劑的珠粒剖面化作業的方 法，該方法包含的步驟爲： 沿著該晶粒的邊緣將包封劑的珠粒沉積在線接合上； 將一剖面化作業表面放置在該晶粒之上離該晶粒一預 定間距處； 在該包封劑的珠粒固化之前將該剖面化作業表面移動 橫過該珠粒，用以重塑該珠粒的剖面；及 固化該包封劑的珠粒。 本發明發現，該包封劑可在不從線接合上剝除該包封 劑之下被被一剖面化作業表面有效地形塑。該包封劑珠粒 之正常的外凸形上表面可被該剖面化作業表面推向一側。 藉由此低的包封劑珠粒，該活性表面可被帶引更加緊鄰另 一表面而不相接觸。例如，在一列印頭IC上的噴嘴陣列 -11 - 200915524 可以離該紙張路徑3 00微米至400微米。藉由在施加一包 封劑並對其剖面化作業之前將線接合弧塌陷或平坦化，在 該列印頭1C上的噴嘴陣列可以離該紙張路徑不到1 00微 米。 較佳地，該等線接合延伸成一從該晶粒之各別的接觸 墊到該支撐結構上之對應的導體之弧且該方法包含的步驟 爲. 推擠該線接合用以將該線接合塑性地變形；及 釋放該線接合使得該塑性變形將該線接合保持在一較 平的剖面形狀。 較佳地，該晶粒具有一活性表面其具有功能性元件， 接觸墊其被形成在該活性表面的一個邊緣上，該線接合具 有一小於40微米的直徑且該弧延伸在該晶粒之活性表面 上方大於1〇〇微米處。 較佳地，該等線接合被塑性地變形使得它們延伸於該 晶粒之活性表面上方小於5 0微米處。 較佳地，該線接合藉由與一刀片狀物嚙合而被推擠， 該刀片狀物具有一用來接觸該線接合之圓角化的邊緣區。 較佳地，該包封劑的珠粒具有一經過剖面化的表面， 它是平的，平行於該活性表面且與其相距小於1 〇〇微米。 較佳地，該包封劑的珠粒具有一平的且相對於該活性 表面傾斜之經過剖面化的表面。 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 具有大於700CP的黏度。 -12- 200915524 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 是搖變性的（t h i X 〇 t r 〇 p i c )。 較佳地，該方法進一步包含的步驟爲： 將該剖面化作業表面放置成與該活性表面相鄰並與其 間隔開，用以界定一間隙；及 將包封劑的珠粒施用到該等接觸墊上，使得該珠粒的 一側接觸該剖面化作業表面且該珠粒的一部分延伸至該間 隙內並到達該活性表面。 較佳地，該活性表面具有功能性元件，其與該晶粒上 的接觸墊相距小於260微米。在一更佳的形式中，該晶粒 爲一噴墨列印頭1C且該等功能性元件爲噴嘴，墨水經由 噴嘴被噴出。在一些實施例中，該列印頭1C被安裝在一 印表機內使得在使用期間噴嘴離紙張路徑小於1 00微米。 較佳地，該支撐結構，其具有一晶片安裝區及一導體 安裝區，該晶粒被支撐在該晶片安裝區上，及多個電導體 至少部分地被支撐在該導體安裝區上，其中該晶片安裝區 相對於該導體安裝區被升高。 較佳地，該晶片安裝區相對於該導體安裝區被升高超 過1 0 〇微米。在一特佳的實施例中，該支撐結構具有一級 階介於該晶片安裝區與該導體安裝區之間。 較佳地，該等多個導體被一排沿著最靠近該晶粒的邊 緣之接合墊倂入到一可撓曲的印刷電路板（撓性PCB )中 ，該等接合墊離晶粒上的接觸墊超過2公釐。 較佳地，該支撐結構爲一液晶聚合物（LCP )模製物 -13- 200915524 依據第四態樣，本發明提供一種將包封劑施用於一安 裝在一支撐基材上的晶粒上的方法，該方法包含的步驟爲 提供一安裝在一支撐基材上的晶粒，該晶粒具有一與 該支撐結構接觸的背面及一與該背面相反之活性表面，該 活性表面具有電接觸墊； 將一阻障物放置在鄰近該等電接觸墊處且與該活性表 面間隔開用以界定一間隙；及 沉積一珠粒的包封劑於該等電接觸墊上使得該等珠粒 的一側接觸該阻障物且該珠粒的一部分延伸至該間隙中並 到達該活性表面上。 將一阻障物放置在該活性表面上使得它界定一窄的間 距讓該包封劑前端（介於該包封劑與該活性表面之間的接 觸線）的形狀能夠被更嚴密地被控制。來自針頭之包封劑 的任何流率上的變化會造成在珠粒及/或珠粒的P C B側 在高度上的壟起或凹陷。介於該阻障物與該活性表面之間 的間隙所產生之流體阻力係指流入該間隙及流到該活性表 面上的的包封劑量幾乎是固定的。減小的流動變化讓該包 封劑前端緊密地對應該阻障物的形狀。更大的包封劑前端 控制讓該晶粒之活性表面上的功能性元件能夠更靠近接觸 墊。 較佳地，該阻障物爲一剖面化作業表面且該方法進一 步包含的步驟爲： -14- 200915524 將該剖面化作業表面移動於該活性表面上方，用以將 包封劑的珠粒平坦化。 較佳地，該方法進一步包含的步驟爲： 在沉積該包封劑的珠粒之前，用線接合將該晶粒上的 接觸墊電連接至該支撐基材上各別的導體，該等線接合每 一者都延伸一從該接觸墊到該導體的弧； 推擠該線接合用以讓該弧塌陷並將該線接合塑性地變 形；及 釋放該線接合使得該塑性變形將該線接合保持在一較 平的剖面形狀。 在一更佳的形式中，該活性表面其具有功能性元件， 接觸墊其被形成在該活性表面的一個邊緣上，該線接合具 有一小於40微米的直徑且該弧延伸在該晶粒之活性表面 上方大於100微米處。 較佳地，該線接合被塑性地變形使得它們延伸於該晶 粒之活性表面上方小於50微米處。在另一較佳的形式中 ，該線接合藉由與一刀片狀物嚙合而被推擠，該刀片狀物 具有一用來接觸該線接合之圓角化的邊緣區。 較佳地，該包封劑的珠粒具有一經過剖面化的表面， 它是平的，平行於該活性表面且與其相距小於1 〇〇微米。 較佳地，該包封劑的珠粒具有一平的且相對於該活性 表面傾斜之經過剖面化的表面。 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 具有大於700cp的黏度。 -15- 200915524 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 是搖變性的（thixotropic)。 較佳地，該活性表面具有功能性元件，其與該晶粒上 的接觸墊相距小於260微米。在一特佳的形式中，該晶粒 爲一噴墨列印頭I C且該等功能性元件爲噴嘴，墨水經由 噴嘴被噴出。較佳地，該列印頭1C被安裝在一印表機內 使得在使用期間噴嘴離紙張路徑小於1 〇〇微米。 較佳地，該支撐結構具有一晶片安裝區及一導體安裝 區，該晶粒被支撐在該晶片安裝區上，及多個電導體至少 部分地被支撐在該導體安裝區上，其中該晶片安裝區相對 於該導體安裝區被升高。在一特佳的形式中，該晶片安裝 區相對於該導體安裝區被升高超過100微米。在較佳的實 施例中，該支撐結構具有一級階介於該晶片安裝區與該導 體安裝區之間。在特佳的實施例中，該等多個導體被一排 沿著最靠近該晶粒的邊緣之接合墊倂入到一可撓曲的印刷 電路板（撓性P C B )中，該等接合墊離晶粒上的接觸墊超 過2公釐。 較佳地，該支撐結構爲一液晶聚合物（L C P )模製物 〇 依據第五態樣，本發明提供一種施用包封劑至介於一 晶粒與一支撐基材上的導體之間的線接合上的方法，該方 法包含的步驟爲： 形成該包封劑的珠粒於一剖面化作業表面上； 放置該剖面化作業表面使得該珠粒接觸該晶粒；及 -16- 200915524 相對於該晶粒移動該剖面化作業表面，用以用該包封 劑覆蓋該等線接合。 用一剖面化作業表面將包封劑刮掃過該等線接合可提 供該包封劑前端的控制以及該包封劑相對於該晶粒的高度 的控制。該剖面化作業表面相對於該晶粒的運動可被嚴密 地控制用以將包封劑形塑成所想要的形式。使用一列印頭 晶粒的例子，該包封劑可被形塑用以呈現一從該噴嘴表面 升高該等線接合之上的一高點之傾斜面。這可被列印頭維 修所利用，藉以便於維持固定的接觸壓力於該刮掃機構上 。這藉由參照圖式在下文中進一步說明。然而，將可被瞭 解的是，該包封劑可藉由使用特定形狀的剖面化作業表面 及詳對於該晶粒的運動來形塑用以具有凸脊，邊溝，溝槽 等等。 較佳地，該方法進一步包含的步驟爲： 將該剖面化作業表面浸泡在該包封劑物質的容器內用 以形成一包封劑的珠粒於該剖面化作業表面上。 選擇上地，該剖面化作業表面爲一具有筆直邊緣的刀 片狀物且該方法進一步包含的步驟爲： 將該刀片狀物定向（orienting )使得該筆直的邊緣是 最低的邊緣及將該筆直的邊緣浸泡在該包封劑物質中用以 沿著該筆直的邊緣形成該包封劑的珠粒。 較佳地，該晶粒具有一帶有功能性元件之活性表面及 多個沿著一邊緣被形成的接觸墊用以與該等線接合接觸， 使得該等線接合延伸成爲一從該等接觸墊分別到達每一導 -17- 200915524 體的弧，該等線接合具有一小於40微米的直徑及該弧延 伸在該晶礪之有足用的表面上方高於100微米處。 較佳地，該方法進一步包含的步驟爲： 在包封2 Μ ’推擠該線接合用以讓該弧塌陷並將該線 接合塑性地變形；及 釋放該線接合使得該塑性變形將該線接合保持在一較 平的剖面形狀。 較佳地’該等線接合被塑性地變形使得它們延伸於該 晶粒之活性表面上方小於5 0微米處。較佳地，該線接合 藉由與一刀片狀物嚙合而被推擠，該刀片狀物具有一用來 接觸該線接合之圓角化的邊緣區。 較佳地，覆蓋該等線接合之包封劑具有一經過剖面化 的表面，它是平的，平行於該活性表面且與其相距小於 100微米。 較佳地，該包封劑的珠粒具有一平的且相對於該活性 表面傾斜之經過剖面化的表面。 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 具有大於700cp的黏度。 較佳地，該包封劑是一環氧樹脂物質，其在未固化時 是搖變性的（thixotropic )。較佳地，該等功能性元件與 該晶粒上的接觸墊相距小於2 6 0微米。在一更佳的形式中 ，該晶粒爲一噴墨列印頭1C且該等功能性元件爲噴嘴， 墨水經由噴嘴被噴出。選擇上地’該列印頭1C被安裝在 一印表機內使得在使用期間噴嘴離紙張路徑小於1 〇〇微米 -18- 200915524 較佳地，該支撐結構具有一晶片安裝區及一導體安裝 區，該晶粒被支撐在該晶片安裝區上，及多個電導體至少 部分地被支撐在該導體安裝區上，其中該晶片安裝區相對 於該導體安裝區被升高。在一特佳的形式中，該晶片安裝 區相對於該導體安裝區被升高超過100微米。在另一較佳 的形式中，該支撐結構具有一級階介於該晶片安裝區與該 導體安裝區之間。在一較佳的實施例中，該等多個導體被 一排沿著最靠近該晶粒的邊緣之接合墊倂入到一可撓曲的 印刷電路板（撓性PCB )中，該等接合墊離晶粒上的接觸 墊超過2公釐。較佳地，該支撐結構爲一液晶聚合物（ LCP )模製物。 【實施方式】 圖1顯示用來施用一包封劑珠粒至線接合上之一般的 技術。一晶粒4被安裝到一支撐結構6上鄰近一撓性PCB 8(可撓曲的印刷電路板）的邊緣處。該晶粒4具有一排 接觸墊10沿著一個邊緣且該撓性PCB 8具有對應的接合 塾12。線接合16從接觸塾10延伸至接合塾12。電力及 資料經由該撓性PCB 8內的導電跡線14被傳送至晶粒4 。這是安裝在許多電子裝內之晶粒的簡化代表。安裝在 LCP (液晶聚合物）模製物上用來接受來自一鄰近的撓性 PCB，如美國專利申請案第…號（我們的文件編號 RRC00 1US，其藉由此參照被倂於本文中）中所描述的， -19- 200915524 該列印頭1C晶粒爲此類晶粒安裝構造的一個例子。一般 的從業人員將可瞭解的是’該晶粒可以被直接安裝在一其 上形成有導線之硬式PCB上。 線接合16被覆蓋在一包封劑2的珠粒內用以保護並 補強該等線接合。該包封劑2從一排出針頭1 8直接施用 至線接合1 6上。通常該包封劑珠粒2是三個分開的珠 粒一兩個被稱爲‘水壩（dam )’的包封劑20，及一個被稱 爲‘裝塡物（fill )’的包封劑22。水壩包封劑20的黏度高 於裝塡物包封劑22的黏度，且水壩包封劑20用來形成一 渠道用來容納該裝塡物包封劑珠粒。在該晶粒4上方的該 珠粒2的高度Η通常約5 00-6 00微米。在大多數的電子裝 置中，這並不會產生問題。然而，如果該晶粒具有一活性 表面而必需與另一表面以極接近的方式工作的話，此珠粒 將會是一個障礙。 將該晶粒相對於該撓性P C Β升高 圖2顯示一級階式支撐結構6其將該晶片安裝區26 相對於該PCB安裝區24(或至少是安裝PCB接合墊12 的區域）升高。藉著晶粒4在該升高的晶片安裝區26上 ’線接合1 6的弧相對於晶粒4之活性表面2 8較低。事實 上’線接合16之附著於接觸墊10的端部可以是該弧的頂 點（應記住的是該線接合弧是用來適應晶粒與PCB的某 些相對運動）。當線接合1 6被包封劑2覆蓋住時，該珠 粒具有一在該晶粒4之活性表面28上方之減小的高度Η -20- 200915524 。如果該包封劑珠粒2使用兩個水壩包封劑2 0及一個裝 塡物包封劑22的話，則這些珠粒的位置，體積及黏度必 需將該級階考慮進去。小於1 0 0微米的珠粒高度是可輕易 地達成，且藉由額外的手段，譬如像是線弧塌陷及珠粒剖 面化作業（將於下文中討論），可達成小於5 0微米的珠 粒高度。 藉著晶粒4被升高至該撓性PCB 8之上4 1 0微米，線 接合16的高度在該晶粒之上約34微米。藉著該晶粒被升 高至該撓性PCB 8之上610微米，線接合約爲20微米。 將該晶粒再升高，則線接合高度的再降低程度很小或未再 降低（710微米之階級具有約20微米的線接合高度）。 用一剖面作業刀片狀物來形塑該包封劑珠粒 圖3Α至3C顯示該包封劑2被用一剖面作業刀片狀 物3 0加以剖面作業。該支撐結構6再次被級階化用以減 小線接合16在該晶粒4之上的高度。在該環氧樹脂包封 劑2固化之前，該剖面作業刀片狀物3 0在一預定的路徑 上移動橫過該晶粒4與線接合。如圖3 Β所示，刀片狀物 30將珠粒的頂部移至其撓曲PCB側用以形成一平坦的頂 面32，其位在該晶粒4之上顯著減小的高度Η處。 該包封劑珠粒2如圖1及2所示地可以多個分開的珠 粒，或可以是一種物質的單一珠粒。然而，爲了要該經過 剖面作業化之包封劑的更嚴密的尺寸控制，所用之包封劑 應是搖變性的（thixotropic )，當從該排出針頭被沉積之 -21 - 200915524 後，或被該刀片狀物3 0剖面化之後’該物質不應因其本 身的重量而流動’而應維持其形狀直到它固化爲止。這需 要該環氧樹脂具有—大於約70 0cP之未固化的黏度。一適 合的包封劑爲由 Dymax公司所製造的DYMAX 900 1 -E-V3.1晶片包封劑’其在未固化時具有約800cp的黏度。該 刀片狀物3 0可以是陶瓷（玻璃）或金屬且較佳地約2 0 0 微米厚。 將可被瞭解的是，該刀片狀物3 0與晶粒4的相對運 動可被精確地控制。這可讓該高度H由線接合處理的公 差來決定。只要H大於在該晶粒之上之線接合弧的標稱 高度加上最大公差，包封劑2將可覆蓋並保護線接合1 6 。藉此技術，高度Η可輕易地從500-600微米被減小至小 於3 0 0微米。如果線接合弧的高度亦被減小的話，該包封 劑珠粒的高度Η可小於100微米。本案申請人使用此技 術來將列印頭晶粒上的包封劑剖面化使其在低點的高度低 至5 0微米。如圖3 C所示，該最低點是位在該包封劑前端 且該刀片狀物3 0在珠粒2的頂部形成一傾斜面3 2。該傾 斜面可在從噴嘴面上清除掉紙張灰塵與乾掉的墨水時被列 印頭維修系統所利用。這顯示出此技術的能力不僅僅可減 小該包封劑珠粒的高度，還可以形成一實施包封線接合之 外的其它功能的表面。該刀片狀物的邊緣剖面及該刀片狀 物相對於該晶粒的路徑可被構建來形成一表面，其具有用 於各種目地的各式形狀。 -22- 200915524 線接合弧的塑性變形 圖4A至4C顯示用於降低線接合的剖面的 術。圖4 A顯示透過線接合1 6連接至撓性P C B 8 。雖然該級階式支撐結構6已相較於平的支撐結 合弧的高度降低，但線接合仍具有一向上彎曲的 ’而不是向下朝向該級階的角落。線接合1 6的 地約32微米且具有約3至5克力的拉力。該拉 斷與接觸墊10或接合墊12的連接所需的拉力負 這些結構的脆弱性（其中的一個原因是施用包封 以傳統上的智慧是避免線接合弧與其它實心表面 如圖4 B所示，線接合1 6的弧可被線推壓 塌。該線推壓件34推移線該接合1 6使其足以將 地及塑性地變形。本案申請人已展示與該線推壓 觸會造成在該電線上之決部化的加工硬化，但只 沒有過大’它就不會斷裂。該線推壓件3 4的端 化用以避免應力集中點。此線推壓件3 4可以是 單一線接合相接觸的尖筆（stylus )或是用來同 個線接合的刀片狀物。 現參照圖4C，該線推壓件34被縮回且該電 原來的形狀回彈用以解除該彈性變形。然而，該 仍繼續存在且在該晶粒4之上的線接合高度被大 。5式驗顯不使用此技術可讓一最初爲200微米的 圈高度被減小至約3 5微米。試驗亦顯示被塑性 線的拉扯強度仍保持在約3至5克力。 另一種技 的晶粒4 構將線接 自然傾向 直徑典型 力爲破弄 荷。由於 劑），所 接觸。 :3 4弄坍 該弧彈性 件34接 要該力量 部被圓角 一用來與 時推壓多 線朝向其 塑性變形 幅地減小 線接合環 變形的電 -23- 200915524 線接合的塌陷是未被控制的且讓線接合有點被隨機地 變形。然而，將線接合推移更靠近該晶粒可提供被更一致 地形塑之坍塌的線接合。本案申請人的硏究顯示對於該晶 粒而言接觸200至300微米的電線可提供最佳的結果。 如圖4D所示，晶粒4與撓性PCB 8被安裝在一平的 支撐結構6上。如上文中討論的，這表示該線接合弧的最 初環圈高度是高出許多的_約在該晶粒4之上約400微米 。因此，在該環圈被該線推壓件推壓坍塌時該電線具有更 多的塑性變形。即便如此，本案申請人的結果顯示，在推 壓之後之剩餘的環圈高度約爲20-50微米。 圖5A及5B顯示被一包封劑珠粒2所覆蓋之坍塌的 線接合1 6。即使是在固化之前沒有珠粒剖面化作業，該 珠粒在該晶粒之上的高度Η仍遠小於該珠粒包封原始之 未變形的電線環圈所需的高度。 用剖面化作業刀片狀物施用包封劑 圖6Α，6Β及6C顯示使用該剖面化作業刀片狀物30 代替一排出針頭（參見圖1及2 )來施用包封劑珠粒。如 先前討論過的，來自該排出針頭的包封劑流率會改變且這 對於包封劑前端在晶粒4之活性表面上的位置會產生大的 變化。因此，在晶粒4之活性表面上的任何功能性元件都 必需與接觸墊1 0充分地間隔開用以容許緩慢而曲折地前 進的包封劑前端。 用剖面化作業刀片狀物施用包封劑可避免來自該排出 -24- 200915524 針頭的流率波動所造成的問題。如圖6A所示，該包封劑 珠粒40可單純地藉由將該剖面化作業刀片狀物30浸泡至 一未固化的包封劑環氧樹脂的容器內而被形成在該剖面化 作業刀片狀物30上。當然，該珠粒40亦可藉由其它的傳 統方式，譬如將該排出針頭沿著該刀片狀物30的一端移 動，來形成。 圖6B顯示該刀片狀物30已被降低用以將該珠粒40 接觸到該晶粒4上。當該包封劑物質接觸該晶粒表面時， 它沿著該表面濕潤，同時保持被該刀片狀物的邊緣壓住。 該刀片狀物30被保持在該晶粒4之上一預定的高度且被 移動橫過該珠粒2用以將該珠粒平坦化及降低其剖面。被 該刀片狀物3 0從該珠粒2的頂端移位的包封劑被散佈在 該珠粒2的PCB側上。該包封劑是否比所必要更散佈於 該PCB上是無關緊要的。只要線接合16與接合墊12被 覆蓋及可，任何額外的包封劑在該PCB 8表面上都不會是 有害的。 在圖6C中，線接合16高度已藉由依據上述的技術將 該電線弧塌陷來加以降低。如之前討論過的，被該排出針 頭所放置的珠粒2不需要大到能夠覆蓋住該線接合1 6坍 塌時的大小。再者，當對該包封劑2實施剖面化作業時， 該刀片狀物3 0可更靠近該晶粒4而不與線接合1 6接觸。 因此，在圖6C中的珠粒剖面比圖6B中的珠粒剖面要來 得低。 -25- 200915524 包封劑前端控制 當該包封劑物質從該排出針頭被施用時，在流率上的 微小變化會造成珠粒在較大流量的位置點處壟起。因此， 該珠粒之與該晶粒之活性表面接觸的一側不是筆直的，而 是有顯著的擾亂（perturbation)。這些擾亂必需要被容 納在接觸墊與該活性表面上之任何功能性元件之間。介於 接觸墊與功能性元件之間的間距會使用掉有價値的‘晶片 不動產（chip real estate) ’。本案申請人之前已開發出在 接觸墊與第一排噴嘴之間有260微米的間距的列印頭晶粒 。更佳的包封劑前端控制可減小接點與作業元件之間的間 距，以及晶粒的整體尺寸。因此，此設計可更加精巧且從 原始的晶圓片上可作出更多的晶片。 如圖7A及7B所示，該剖面化作業刀片狀物30被用 來控制包封劑珠粒2的前端3 6。該刀片狀物3 0被放置在 該晶粒4之上用以在其下緣與該活性表面2 8之間界定一 間隙42。當該排出針頭1 8排出出該包封劑物質44時’ 其流動在該活性表面上，該刀片狀物的一側與該物質帶（ materia 1 filet )延展通過該間隙42。由於該間隙所產生之 流動阻力的關係，所以流量變動對於流經該間隙的物質帶 的尺寸只有很小的影響。因此，該包封劑前端3 6很接近 地符合該刀片狀物3 0的下緣的線。 如圖7 B所示，該剖面化作業刀片狀物3 0在該包封劑 珠粒2從該排出針頭被排出來時就已經在定位上要對該包 封劑珠粒實施剖面化作業。該刀片狀物3 0單純地只是在 -26- 200915524 一遠離噴嘴38的方向上移動於該晶粒4的上方。這可將 該包封劑前端3 6保持在定位並將線接合1 6上放之包封劑 珠粒2的剖面平坦化。 本發明已在本文中以舉例的方式加以描述°熟習此技 藝者將可輕易地認知到許多未偏離本發明之廣意的發明性 槪念的精神與範圍的變化與修改。 【圖式簡單說明】 本發明的實施例現將以舉例的方式參照附圖加以描述 ，其中： 圖1爲用來施用一珠粒的封包劑於線接合上之一般先 前技藝技術的示意代表圖； 圖2爲安裝於一支撐結構上之晶粒的示意代表圖，該 支撐結構具有相對於該撓性PCB安裝區被升高的晶片安 裝區； 圖3A’3B及3C爲該包封劑珠粒藉由使用一活動的 刀片狀物而被剖面化成爲一所想要的形狀之示意代表圖； 圖4A至4D爲被塑性便形剖面化的線接合的示意代 表圖； 圖5 A及5 B顯示被塑性變形之線接合之包封劑珠粒 高度的減小： 圖6A至6C顯示該包封劑珠粒藉由使用該剖面化作 業的刀片狀物而被施加至線接合；及 圖7A及7B顯示被用來控制該晶粒的表面上的包封 -27- 200915524 劑珠粒的剖面化作業刀片狀物。 【主要元件符號說明】 4 :晶粒 6 :支撐結構 8 :撓性P C B 1 〇 :接觸墊 1 2 :接合墊 1 4 :導電跡線 1 6 .線接合 1 8 :排出針頭 2 :包封劑 2 0 :水壩包封劑 2 2 :裝塡包封劑 24: PCB安裝區 26 :晶片安裝區 2 8 :活性表面 3 0 :剖面化作業刀片狀物 3 2 :平坦的頂面 3 4 :線推壓件 4 0 :包封劑珠粒 3 6 :包封劑前端 4 2 ··間隙 4 4 :包封劑物質 -28 200915524 3 8 :噴嘴 -29-200915524 IX. Description of the Invention [Technical Field of the Invention] The present invention relates to the field of integrated circuit packaging. In particular, the present invention relates to wire bond encapsulation between a circuit board and a contact pad on an integrated circuit die. [Prior Art] An integrated circuit fabricated on a germanium wafer substrate is electrically connected to a printed circuit board by wire bonding. Wire bonding is a very thin wire having a diameter of about 25 to 40 microns - a contact that extends from the side of the wafer substrate along the sides of the wafer substrate to the printed circuit board (PCB). To protect and strengthen the wire bonds, the wire bonds are sealed in an epoxy bead called an encapsulant. The wires from the contact pads to the PCB are made longer than needed to accommodate the change in the gap between the PCB and the contact pads due to thermal expansion, buckling of the components, and the like. These wires, which are longer than necessary, naturally form an arc between the contact pads and P C B . The top end of the wire arc is typically about 300 microns above the contact pad, but some wire bonds will extend even higher. As its name is reminiscent of, the encapsulant must enclose the length of the entire wire, so the encapsulant beads will extend from 500 microns to 600 microns above the contact pad. The integrated circuit fabricated on a germanium wafer substrate is commonly referred to as a 'die'. For the purposes of this specification, the term dies will be used to refer to an integrated circuit fabricated on a wafer substrate using photolithographic techniques (usually used in etching and deposition techniques in semiconductor fabrication). If the die is purely a microprocessor of the stomach -5 - 200915524, it is less desirable to maintain tight control of the size of the encapsulant beads. However, if the die is a microelectromechanical system (MEMS) device having an active upper surface, it is necessary or desirable to have the active surface of the die in close proximity to the other surface. This applies to inkjet printheads. The proximity of the print media to the nozzle array can affect print quality. Similarly, if a cleaning surface is swept across the nozzle, the beads of the encapsulant will interfere with the wiping contact. Another problem is that the sides of the encapsulant beads are not straight. One technique commonly used to deposit the encapsulant involves extruding the encapsulant directly from a needle to a row of wire bonds. The volume of the encapsulant and the placement on the grains are not very precise. A slight change in the pressure of the pump or the speed of the needle causes the side of the bead that is in contact with the active surface to be substantially curved. When the side of the bead is not straight, it must be suitably spaced apart from any active component on the active surface to accommodate the perturbation generously. Interscribing the electrical contacts to the active portion of the active surface (e.g., an inkjet nozzle) can deplete the valuable wafer resources and reduce the number of grains that can be fabricated from a wafer. In view of the widespread use of ink jet print heads, the present invention will be described, inter alia, as an application in this field. However, it will be understood by those of ordinary skill that this is purely exemplary and that the invention is equally applicable to integrated circuits that are wire bonded to a PCB or other support structure. SUMMARY OF THE INVENTION According to a first aspect, the present invention provides a microprocessor device, the package -6-200915524 comprising: a support structure having a wafer mounting area and a conductor mounting area; an ink jet print head 1C Supported on the wafer mounting area, the ink jet print head 1C has a back surface in contact with the wafer mounting area and an active surface opposite the back surface. The active surface has electrical contact pads and an array of sprays An ink nozzle; a plurality of electrical conductors at least partially supported on the conductor mounting region: and a series of wire bonds extending from the electrical contact pads to a plurality of electrical conductors supported on the conductor mounting region; Wherein the wafer mounting area is raised relative to the conductor mounting area. By raising the wafer mounting area relative to other portions of the PCB, or at least to the conductors of the wire-bonded PCB ends, the top end of the arc formed by the layer is closer to the active surface of the die. This allows the beads of the encapsulant to have a lower profile relative to the active surface. With this low encapsulant bead, the active surface can be brought closer to the other surface without contact. For example, the array of nozzles on a column of print heads 1C can be from 300 microns to 400 microns from the paper path. Preferably, the wafer mounting area is raised by more than 1 〇〇 micrometer relative to the conductor mounting area. Preferably, the support structure has a first order between the wafer mounting area and the conductor mounting area. Preferably, the plurality of conductors are inserted into the flexible printed circuit board (flexible pc B ) by a row of bond pads closest to the edge of the die, the bond pads being separated from the die The contact pads on the top are over 2 mm. -7- 200915524 Preferably, the wire bonds are formed from wires having a diameter of less than 40 microns and extending less than 100 microns above the active surface of the die. Preferably, the wire bonds are plastically deformed such that they extend less than 50 microns above the active surface of the die. Preferably, the active surface has a functional element that is less than 260 microns from the contact pads on the die. In a particularly preferred form, the die is an ink jet print head 1C and the functional elements are nozzles through which ink is ejected. In some embodiments, the support structure is a liquid crystal polymer (LCP) molding. Preferably, the wire bonds are covered in a bead of an encapsulant which extends less than 200 microns above the active surface of the die. Preferably, the wire bonds are covered in a bead of an encapsulant. The beads of the encapsulant have a profiled surface which is flat 'parallel to the active surface and less than 100 apart Micron. Preferably, the wire bonds are covered in a bead of an encapsulant' the beads of the encapsulant have a flat, profiled surface that is inclined relative to the active surface. Preferably, the wire bonds are covered in a bead of an encapsulant 'the encapsulant is an epoxy material' which is thixotropic when uncured. Preferably, the wire bonds are covered in the beads of the encapsulant. The encapsulant is an epoxy material which has a viscosity of greater than 700 cp when uncured. -8- 200915524 In a particular embodiment, the printhead IC is mounted in a printer such that the nozzle is less than 10 microns from the paper path during use. According to a second aspect, the present invention provides a method of wire bonding profile work between a contact pad on a die and a conductor on a support structure, the method comprising the steps of: bonding the wire with a wire bond a contact pad on the granule electrically connected to the conductor on the support structure, the wire bond extending into an arc from the contact pad to the conductor; pushing the wire bond to collapse the arc and plastically deform the wire bond And releasing the wire bond such that the plastic deformation maintains the wire bond in a relatively flat cross-sectional shape. The strength of the wire joint is quite small, on the order of 3 to 5 grams force. However, Applicants' investigations have shown that the wire joint structure is strong enough to withstand a certain degree of work hardening from plastic deformation. The wire-engaging arc can be deformed into a flat profile without sacrificing electrical connection to the PCB. Preferably, the die has an active surface having a functional element, the contact pad being formed on an edge of the active surface, the wire bond having a diameter of less than 40 microns and the arc extending over the die Above the active surface is greater than 100 microns. Preferably, the wire bonds are plastically deformed such that they extend less than 50 microns above the active surface of the die. Preferably, the wire bond is pushed by engagement with a blade having a filleted edge region for contacting the wire bond. Preferably, the method further comprises the steps of: -9-200915524 applying an encapsulating bead to the wire bonding; and moving a profiled working surface over the active surface for the encapsulating agent The beads are flattened. Preferably, the beads of the encapsulant have a profiled surface which is flat, parallel to the active surface and spaced less than 100 microns apart. Preferably, the beads of the encapsulant have a flat, profiled surface that is inclined relative to the active surface. Preferably, the encapsulant is an epoxy material having a viscosity greater than 700 cp when uncured. In a preferred embodiment, the encapsulant is an epoxy material that is thixotropic when uncured. Preferably, the method further comprises the steps of: a surface disposed adjacent to and spaced apart from the active surface to define a gap; and applying a bead of the encapsulant to the contact pads such that one side of the bead contacts the profiled work surface and the A portion of the beads extend into the gap and reach the active surface. Preferably, the active surface has a functional element 'which is less than 260 microns from the contact pads on the die. In a particularly preferred form, the die is an ink jet print head IC and the functional elements are nozzles through which ink is ejected. In some embodiments, the printhead 1C is mounted in a printer such that the nozzles are less than 100 microns from the paper path during use. Preferably, the support structure has a wafer mounting area and a conductor mounting area, the die is supported on the wafer mounting area and a plurality of electrical conductors-10-200915524 are at least partially supported on the conductor mounting On the area, wherein the wafer mounting area is raised relative to the conductor mounting area. Preferably, the wafer mounting area is raised by more than 100 microns relative to the conductor mounting area. Preferably, the support structure has a first order between the wafer mounting area and the conductor mounting area. In some embodiments, the plurality of conductors are punctured into the flexible printed circuit board (flexible PCB) by a row of bond pads proximate the edge of the die, the bond pads being detached from the crystal The contact pads on the granules are more than 2 mm. Preferably, the support structure is a liquid crystal polymer (LCP) molding. According to a third aspect, the present invention provides a bead of an encapsulant extending along an edge of a die mounted on a support structure. A method of grain profile operation, the method comprising the steps of: depositing beads of an encapsulant on a wire bond along an edge of the die; placing a profiled work surface on the die from the die At a predetermined spacing; moving the profiled working surface across the beads prior to curing of the encapsulant beads to reshape the cross-section of the beads; and curing the beads of the encapsulant. The present inventors have discovered that the encapsulant can be effectively formed by a profiled work surface without stripping the encapsulant from the wire bond. The normal convex upper surface of the encapsulant bead can be pushed to one side by the profiled work surface. With this low encapsulant bead, the active surface can be brought closer to the other surface without contact. For example, nozzle arrays -11 - 200915524 on a single printhead IC can be from 300 microns to 400 microns from the paper path. The nozzle array on the print head 1C can be less than 100 micrometers from the paper path by collapsing or flattening the wire bond arc prior to applying a sealant and contouring it. Preferably, the wire bonds extend into an arc from respective contact pads of the die to corresponding conductors on the support structure and the method includes the steps of: pushing the wire bond to bond the wire Plastically deforming; and releasing the wire bond such that the plastic deformation maintains the wire bond in a relatively flat cross-sectional shape. Preferably, the die has an active surface having a functional element, the contact pad being formed on an edge of the active surface, the wire bond having a diameter of less than 40 microns and the arc extending over the die Above the active surface is greater than 1 〇〇 micron. Preferably, the wire bonds are plastically deformed such that they extend less than 50 microns above the active surface of the die. Preferably, the wire bond is pushed by engagement with a blade having a filleted edge region for contacting the wire bond. Preferably, the beads of the encapsulant have a profiled surface which is flat, parallel to the active surface and less than 1 〇〇 microns apart. Preferably, the beads of the encapsulant have a flat, profiled surface that is inclined relative to the active surface. Preferably, the encapsulant is an epoxy material having a viscosity greater than 700 CP when uncured. Preferably, the encapsulant is an epoxy material which is thixotropy (t h i X 〇 t r 〇 p i c ) when uncured. Preferably, the method further comprises the steps of: placing the profiled work surface adjacent to and spaced apart from the active surface to define a gap; and applying the beads of the encapsulant to the contacts The pad is such that one side of the bead contacts the profiled working surface and a portion of the bead extends into the gap and reaches the active surface. Preferably, the active surface has a functional element that is less than 260 microns from the contact pads on the die. In a more preferred form, the die is an ink jet print head 1C and the functional elements are nozzles through which ink is ejected. In some embodiments, the printhead 1C is mounted in a printer such that the nozzles are less than 100 microns from the paper path during use. Preferably, the support structure has a wafer mounting area and a conductor mounting area, the die is supported on the wafer mounting area, and a plurality of electrical conductors are at least partially supported on the conductor mounting area, wherein The wafer mounting area is raised relative to the conductor mounting area. Preferably, the wafer mounting area is raised by more than 10 〇 microns relative to the conductor mounting area. In a particularly preferred embodiment, the support structure has a first order between the wafer mounting area and the conductor mounting area. Preferably, the plurality of conductors are inserted into a flexible printed circuit board (flexible PCB) by a row of bond pads closest to the edge of the die, the bond pads being separated from the die The contact pads are over 2 mm. Preferably, the support structure is a liquid crystal polymer (LCP) molding-13-200915524. According to a fourth aspect, the present invention provides an application of an encapsulant to a die mounted on a support substrate. The method comprises the steps of providing a die mounted on a support substrate having a back surface in contact with the support structure and an active surface opposite the back surface, the active surface having electrical contact a pad; a barrier disposed adjacent to the electrical contact pads and spaced apart from the active surface to define a gap; and an encapsulant depositing a bead on the electrical contact pads such that the beads One side contacts the barrier and a portion of the bead extends into the gap and onto the active surface. Placing a barrier on the active surface such that it defines a narrow spacing such that the shape of the front end of the encapsulant (the line of contact between the encapsulant and the active surface) can be more tightly controlled . Any change in flow rate from the encapsulant of the needle can cause ridges or depressions in the height on the P C B side of the beads and/or beads. The fluid resistance created by the gap between the barrier and the active surface means that the encapsulation dose flowing into the gap and flowing to the active surface is almost fixed. The reduced flow variation allows the front end of the encapsulant to closely correspond to the shape of the barrier. A larger encapsulant front end control allows the functional elements on the active surface of the die to be brought closer to the contact pads. Preferably, the barrier is a profiled work surface and the method further comprises the steps of: -14- 200915524 moving the profiled work surface over the active surface to flatten the beads of the encapsulant Chemical. Preferably, the method further comprises the steps of: electrically bonding the contact pads on the die to respective conductors on the support substrate by wire bonding prior to depositing the beads of the encapsulant, the wires Each of the joints extends an arc from the contact pad to the conductor; pushing the wire bond to collapse the arc and plastically deform the wire bond; and releasing the wire bond such that the plastic deformation joins the wire Maintain a flat cross-sectional shape. In a more preferred form, the active surface has a functional element, the contact pad being formed on an edge of the active surface, the wire bond having a diameter of less than 40 microns and the arc extending over the die Above the active surface is greater than 100 microns. Preferably, the wire bonds are plastically deformed such that they extend less than 50 microns above the active surface of the grain. In another preferred form, the wire bond is pushed by engagement with a blade having a filleted edge region for contacting the wire bond. Preferably, the beads of the encapsulant have a profiled surface which is flat, parallel to the active surface and less than 1 〇〇 microns apart. Preferably, the beads of the encapsulant have a flat, profiled surface that is inclined relative to the active surface. Preferably, the encapsulant is an epoxy material having a viscosity greater than 700 cp when uncured. -15- 200915524 Preferably, the encapsulant is an epoxy material which is thixotropic when uncured. Preferably, the active surface has a functional element that is less than 260 microns from the contact pads on the die. In a particularly preferred form, the die is an ink jet print head I C and the functional elements are nozzles through which ink is ejected. Preferably, the print head 1C is mounted in a printer such that the nozzle is less than 1 〇〇 micrometer away from the paper path during use. Preferably, the support structure has a wafer mounting area and a conductor mounting area, the die is supported on the wafer mounting area, and a plurality of electrical conductors are at least partially supported on the conductor mounting area, wherein the wafer The mounting area is raised relative to the conductor mounting area. In a particularly preferred form, the wafer mounting area is raised by more than 100 microns relative to the conductor mounting area. In a preferred embodiment, the support structure has a first order between the wafer mounting area and the conductor mounting area. In a particularly preferred embodiment, the plurality of conductors are punctured into a flexible printed circuit board (flexible PCB) by a row of bond pads proximate the edge of the die, the bond pads The contact pads on the die are more than 2 mm. Preferably, the support structure is a liquid crystal polymer (LCP) molding. According to a fifth aspect, the present invention provides an application of an encapsulant to a conductor between a die and a support substrate. a method of wire bonding, the method comprising the steps of: forming a bead of the encapsulant on a profiled work surface; placing the profiled work surface such that the bead contacts the die; and -16 - 200915524 relative The profiled work surface is moved to the die to cover the wire bond with the encapsulant. Sweeping the encapsulant through the wire bond with a profiled work surface provides control of the front end of the encapsulant and control of the height of the encapsulant relative to the die. The movement of the profiled work surface relative to the die can be tightly controlled to shape the encapsulant into the desired form. Using an example of a row of die grains, the encapsulant can be shaped to present an inclined surface that raises a high point above the wire bond from the nozzle surface. This can be utilized by the print head maintenance to maintain a constant contact pressure on the sweeping mechanism. This is further explained below by reference to the drawings. However, it will be appreciated that the encapsulant can be shaped to have ridges, sipe, grooves, etc. by using a profiled work surface of a particular shape and detailed movement of the die. Preferably, the method further comprises the step of: immersing the profiled work surface in a container of the encapsulant material to form an encapsulant of beads on the profiled work surface. Selecting the upper surface, the profiled work surface is a blade having a straight edge and the method further comprises the steps of: orienting the blade such that the straight edge is the lowest edge and the straight edge An edge is immersed in the encapsulant material to form beads of the encapsulant along the straight edge. Preferably, the die has an active surface with a functional component and a plurality of contact pads formed along an edge for engaging the wires such that the wire bonds extend from the contact pads The arcs of each of the -17-200915524 bodies are respectively reached, the wire bonds having a diameter of less than 40 microns and the arc extending above the 100 microns above the sufficient surface of the wafer. Preferably, the method further comprises the steps of: pushing the wire bond at the encapsulation 2 用以 to collapse the arc and plastically deforming the wire bond; and releasing the wire bond such that the plastic deformation deforms the wire The joint remains in a relatively flat cross-sectional shape. Preferably, the wire bonds are plastically deformed such that they extend less than 50 microns above the active surface of the die. Preferably, the wire bond is pushed by engagement with a blade having a filleted edge region for contacting the wire bond. Preferably, the encapsulating agent covering the wire bonds has a profiled surface which is flat, parallel to the active surface and spaced less than 100 microns apart therefrom. Preferably, the beads of the encapsulant have a flat, profiled surface that is inclined relative to the active surface. Preferably, the encapsulant is an epoxy material having a viscosity greater than 700 cp when uncured. Preferably, the encapsulant is an epoxy material which is thixotropic when uncured. Preferably, the functional elements are less than 260 microns from the contact pads on the die. In a more preferred form, the die is an ink jet print head 1C and the functional elements are nozzles through which ink is ejected. Selecting the upper land 'the print head 1C is mounted in a printer such that the nozzle is less than 1 〇〇 micrometer -18-200915524 during use. Preferably, the support structure has a wafer mounting area and a conductor mounting The die is supported on the wafer mounting region and a plurality of electrical conductors are at least partially supported on the conductor mounting region, wherein the wafer mounting region is raised relative to the conductor mounting region. In a particularly preferred form, the wafer mounting area is raised by more than 100 microns relative to the conductor mounting area. In another preferred form, the support structure has a first order between the wafer mounting area and the conductor mounting area. In a preferred embodiment, the plurality of conductors are punctured into a flexible printed circuit board (flexible PCB) by a row of bond pads closest to the edge of the die. The pad is spaced apart from the die by more than 2 mm. Preferably, the support structure is a liquid crystal polymer (LCP) molded article. [Embodiment] Figure 1 shows a general technique for applying an encapsulant bead to a wire bond. A die 4 is mounted to a support structure 6 adjacent the edge of a flexible PCB 8 (flexible printed circuit board). The die 4 has a row of contact pads 10 along one edge and the flexible PCB 8 has a corresponding bond pad 12. The wire bond 16 extends from the contact weir 10 to the weir 12 . Power and data are transferred to the die 4 via conductive traces 14 within the flexible PCB 8. This is a simplified representation of the die mounted in many electronic packages. Mounted on an LCP (Liquid Crystal Polymer) molding for receiving from a contiguous flexible PCB, such as U.S. Patent Application Serial No. (US Pat. No. PCT00 1 US, which is incorporated herein by reference) As described in the -19-200915524, the print head 1C die is an example of such a die mounting configuration. What a general practitioner will understand is that the die can be mounted directly onto a rigid PCB on which the wires are formed. Wire bonds 16 are covered in the beads of an encapsulant 2 to protect and reinforce the wire bonds. The encapsulant 2 is applied directly from a discharge needle 18 to the wire bond 16. Typically the encapsulant bead 2 is three separate beads, one or two encapsulants 20 referred to as 'dams', and an encapsulant known as 'fill' twenty two. The dam encapsulant 20 has a higher viscosity than the encapsulant 22 and the dam encapsulant 20 is used to form a channel for containing the encapsulant beads. The height Η of the beads 2 above the grains 4 is typically about 50,000 to 00 microns. This does not cause problems in most electronic devices. However, if the grain has an active surface and must work in close proximity to the other surface, the bead will be an obstacle. Elevating the die relative to the flexible PC 图 Figure 2 shows a first step support structure 6 which raises the wafer mounting region 26 relative to the PCB mounting region 24 (or at least the area where the PCB bond pads 12 are mounted) . The arc of the wire bond 16 on the raised wafer mounting region 26 by the die 4 is lower relative to the active surface 28 of the die 4. In fact, the end of the wire bond 16 attached to the contact pad 10 can be the apex of the arc (it should be remembered that the wire bond arc is used to accommodate some relative movement of the die and the PCB). When the wire bond 16 is covered by the encapsulant 2, the bead has a reduced height Η-20-200915524 above the active surface 28 of the die 4. If the encapsulant bead 2 uses two dam encapsulants 20 and one enamel encapsulant 22, the position, volume and viscosity of the beads must take this order into account. Bead heights of less than 100 microns can be easily achieved, and by additional means such as line arc collapse and bead profiling (discussed below), beads of less than 50 microns can be achieved. Grain height. By the die 4 being raised above the flexible PCB 8 by 41 microns, the height of the wire bond 16 is about 34 microns above the die. By the die being raised to 610 microns above the flexible PCB 8, the wire bond is about 20 microns. When the crystal grains are raised again, the degree of further reduction in the wire bonding height is small or not lowered (the class of 710 μm has a wire bonding height of about 20 μm). The encapsulant bead is shaped by a cross-sectional working blade. Figures 3A through 3C show that the encapsulant 2 is profiled with a cross-sectional working blade 30. The support structure 6 is again graded to reduce the height of the wire bond 16 above the die 4. Prior to curing of the epoxy encapsulant 2, the cross-sectional working blade 30 is moved over a predetermined path across the die 4 to engage the wire. As shown in FIG. 3A, the blade 30 moves the top of the bead to its flex PCB side to form a flat top surface 32 that is positioned at a substantially reduced height 之上 above the die 4. The encapsulant bead 2 may have a plurality of separate beads as shown in Figures 1 and 2, or may be a single bead of one substance. However, in order to achieve tighter dimensional control of the cross-sectional working encapsulant, the encapsulant used should be thixotropic, after being deposited from the discharge needle - 21 - 200915524, or After the blade 30 is profiled, 'the substance should not flow by its own weight' and its shape should be maintained until it solidifies. This requires the epoxy to have an uncured viscosity of greater than about 70 °c. A suitable encapsulant is the DYMAX 900 1 -E-V3.1 wafer encapsulant manufactured by Dymax Corporation, which has a viscosity of about 800 cp when uncured. The blade 30 can be ceramic (glass) or metal and is preferably about 200 microns thick. It will be appreciated that the relative motion of the blade 30 to the die 4 can be precisely controlled. This allows the height H to be determined by the tolerance of the wire bonding process. As long as H is greater than the nominal height of the wire bond arc above the die plus the maximum tolerance, the encapsulant 2 will cover and protect the wire bond 16 . With this technique, the height Η can be easily reduced from 500-600 microns to less than 300 microns. If the height of the wire bond arc is also reduced, the height of the encapsulant beads can be less than 100 microns. Applicants have used this technique to profile the encapsulant on the printhead die to a low point height of up to 50 microns. As shown in Fig. 3C, the lowest point is at the front end of the encapsulant and the blade 30 forms an inclined surface 32 at the top of the bead 2. The bevel is used by the printhead service system to remove paper dust and dry ink from the nozzle face. This shows that the ability of this technique not only reduces the height of the encapsulant beads, but also forms a surface that performs other functions than the encapsulation of the wire. The edge profile of the blade and the path of the blade relative to the die can be constructed to form a surface having various shapes for various purposes. -22- 200915524 Plastic deformation of wire engagement arcs Figs. 4A to 4C show a technique for reducing the profile of wire bonding. Figure 4A shows the connection to flexible P C B 8 via wire bond 16 . Although the stepped support structure 6 has been lowered in height compared to the flat support arch, the wire bond still has an upwardly curved ' rather than a downward facing corner of the step. The wire bonds 16 are about 32 microns in ground and have a pulling force of about 3 to 5 grams of force. The pulling force required to break the connection to the contact pad 10 or the bond pad 12 negatives the fragility of these structures (one of the reasons is that applying the encapsulation with conventional wisdom is to avoid wire bonding arcs and other solid surfaces as shown in Figure 4B) As shown, the arc of the wire bond 16 can be collapsed by the wire. The wire pusher 34 pushes the wire 16 to make it sufficiently deformable to plastically and plastically. The applicant has shown that the wire will be pressed against the wire. Causes the work hardening on the wire, but it is not too large 'it will not break. The end of the wire pusher 34 is used to avoid the stress concentration point. The wire pusher 34 can be a stylus that is in contact with a single wire or a blade that is engaged with the same wire. Referring now to Figure 4C, the wire urging member 34 is retracted and the shape of the electrical body is rebounded to release the stylus. Elastic deformation. However, this continues to exist and the wire bond height above the die 4 is large. Equation 5 shows that without this technique, a ring height of initially 200 microns can be reduced to about 35 microns. The test also showed that the pull strength of the plastic line was still maintained at about 3 to 5 gram force. One technique of grain structure is to connect the wire to a natural tendency. The typical force of the diameter is the breaking load. Because of the agent, it is contacted. : 3 4 坍 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧 弧Uncontrolled and the wire joints are somewhat randomly deformed. However, moving the wire bond closer to the die can provide a wire bond that is collapsed by a more consistent topography. The study by the applicant of the present application showed that contacting the 200 to 300 micron wire for the crystal grain provided the best results. As shown in Fig. 4D, the die 4 and the flexible PCB 8 are mounted on a flat support structure 6. As discussed above, this means that the initial loop height of the wire bond arc is much higher - about 400 microns above the die 4. Therefore, the wire has more plastic deformation when the loop is pushed and collapsed by the wire pressing member. Even so, the applicant's results show that the remaining loop height after pushing is about 20-50 microns. Figures 5A and 5B show collapsed wire bonds 16 covered by an encapsulant bead 2. Even without bead profiling prior to curing, the bead height of the bead above the die is still much less than the height required for the bead to encapsulate the original undeformed wire loop. Applying Encapsulant with Profiled Work Blades Figures 6A, 6A and 6C show the use of the profiled work blade 30 instead of a discharge needle (see Figures 1 and 2) to apply the encapsulant beads. As previously discussed, the flow rate of the encapsulant from the discharge needle changes and this produces a large change in the position of the front end of the encapsulant on the active surface of the die 4. Therefore, any functional component on the active surface of the die 4 must be sufficiently spaced apart from the contact pad 10 to permit a slow and tortuous advancement of the encapsulant front end. Application of the encapsulant with a profiled working blade avoids problems caused by fluctuations in flow rate from the discharge-24-200915524 needle. As shown in FIG. 6A, the encapsulant bead 40 can be formed in the profiled work simply by dipping the profiled working blade 30 into a container of an uncured encapsulant epoxy resin. On the blade 30. Of course, the bead 40 can also be formed by other conventional means, such as moving the discharge needle along one end of the blade 30. Figure 6B shows that the blade 30 has been lowered to contact the bead 40 onto the die 4. As the encapsulant material contacts the surface of the die, it wets along the surface while remaining pressed by the edge of the blade. The blade 30 is held a predetermined height above the die 4 and moved across the bead 2 to planarize the bead and reduce its profile. An encapsulant displaced by the blade 30 from the tip end of the bead 2 is spread on the PCB side of the bead 2. Whether or not the encapsulant is more dispersed on the PCB than necessary is irrelevant. Any additional encapsulant will not be detrimental on the surface of the PCB 8 as long as the wire bond 16 and the bond pad 12 are covered and available. In Figure 6C, the wire bond 16 height has been lowered by collapsing the wire arc in accordance with the techniques described above. As previously discussed, the beads 2 placed by the discharge needle need not be large enough to cover the size of the wire joint 16 collapse. Further, when the encapsulant 2 is subjected to a profile operation, the blade 30 may be closer to the die 4 without being in contact with the wire bond 16. Therefore, the bead profile in Fig. 6C is lower than the bead profile in Fig. 6B. -25- 200915524 Encapsulant front end control When the encapsulant material is applied from the discharge needle, a small change in flow rate causes the beads to ridge at a point where the flow rate is large. Therefore, the side of the bead that is in contact with the active surface of the die is not straight, but has significant perturbation. These disturbances must be accommodated between the contact pads and any functional elements on the active surface. The spacing between the contact pads and the functional components uses the price of 'chip real estate'. The applicant of the present application has previously developed a printhead die having a pitch of 260 microns between the contact pad and the first row of nozzles. Better encapsulant front end control reduces the spacing between the contacts and the working elements, as well as the overall size of the die. As a result, this design is more compact and allows more wafers to be made from the original wafer. As shown in Figures 7A and 7B, the profiled working blade 30 is used to control the front end 36 of the encapsulant bead 2. The blade 30 is placed over the die 4 to define a gap 42 between its lower edge and the active surface 28. When the discharge needle 18 discharges the encapsulant material 44, it flows on the active surface, and one side of the blade and the material band (materia 1 filet) extend through the gap 42. Due to the relationship of the flow resistance generated by the gap, the flow rate variation has only a small effect on the size of the material strip flowing through the gap. Thus, the encapsulant front end 36 closely follows the line of the lower edge of the blade 30. As shown in Fig. 7B, the profiled working blade 30 is already positioned to profile the encapsulant beads as the encapsulant beads 2 are discharged from the discharge needle. The blade 30 simply moves over the die 4 in a direction away from the nozzle 38 in -26-200915524. This maintains the front end of the encapsulant 36 in position and flattens the cross-section of the encapsulant bead 2 placed on the wire bond 16. The present invention has been described by way of example only, and it is obvious that those skilled in the art can readily recognize the changes and modifications of the spirit and scope without departing from the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0007] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: FIG. 1 is a schematic representation of a general prior art technique for applying a bead of a bead to a wire bond. Figure 2 is a schematic representation of a die mounted on a support structure having a wafer mounting area raised relative to the flexible PCB mounting area; Figures 3A'3B and 3C are the encapsulant beads The granules are profiled into a schematic representation of a desired shape by using a movable blade; Figures 4A through 4D are schematic representations of wire bonds profiled by plastic profiles; Figures 5A and 5 B shows a reduction in the height of the encapsulant beads joined by the plastically deformed wire: Figures 6A to 6C show that the encapsulant beads are applied to the wire bond by using the blade of the profiled operation; 7A and 7B show the profiled working blades used to control the encapsulated -27-200915524 agent beads on the surface of the die. [Main component symbol description] 4: Die 6: Support structure 8: Flexible PCB 1 〇: Contact pad 1 2: Bonding pad 1 4 : Conductive trace 1 6 . Wire bonding 1 8 : Discharge needle 2 : Encapsulant 2 0 : Dam encapsulant 2 2 : Mounting encapsulant 24 : PCB mounting area 26 : Wafer mounting area 2 8 : Active surface 3 0 : Profiled working blade 3 2 : Flat top surface 3 4 : Line Pushing member 40: encapsulant beads 3 6 : encapsulant front end 4 2 · gap 4 4 : encapsulant material -28 200915524 3 8 : nozzle -29-