1274412 九、發明說明： 【發明所屬之技術領域】 •本發明侧於—種銲墊輯，尤指觸球有高結合力的銲塾結構。 【先前技術】 •鲁在電子產品朝向微型化的趨勢下，載板上的電子接點的開口，例如鋒球鮮 墊(baU pad)或結合銲整(bump pad)的開口，以及填入銲墊的鍚球或凸塊， 其尺寸也跟著愈來愈小。例如：BGA的銲墊寬(pitch)已由lmm縮小成 0.4mm’甚至還有〇· 3mm的需求，而SM的銲墊開口則由350“m縮小至22〇 //m以下，FlipChip的銲墊開口也由ioovjjj縮小至8〇/^等的設計需求。 然而，在微型化的趨勢下封裝製程上面臨到了前所未有的問題。由於銲球 與焊墊的結合強度與接觸面積成正比，因此當隨著尺寸越來越小時，銲球 φ 與焊墊的結合強度也隨著接觸面積變小而降低，進而導致容易在封裝製程 完成後發生脫落、拉離及崩裂(crack)現象。若發生上述現象時將使電子接 點失去連結功能而斷路(open)，因此如何能增強結合強度變成是一個重點。 為了確保不至於發生上述脫落、拉離及崩裂現象，銲球與焊墊的結合強度 必須通過的測試方式如 pull strength、chisel test、ball shear test、 鬲溫儲存與Drop Test等，其中又以Nokia的Drop Test最為嚴格。 在綠色產品如RoHS等趨勢下，電子接點面臨需使用無鉛焊料要求，導致回 焊（IR reflow)溫度由約220°C上升至245-260°C，並使得許多針對焊墊所 5 1274412 進行的表面處理方式，由於並沒有大幅增加銲球與焊墊的結合強度而無法 勝任多次回焊。 ， 目如表面處理的主流技術如下：1) 〇SP(〇rganic Solderability : Preservatives)以化學處理方式來保護銅面使銅面能耐多次在封裝製程 • 中的烘烤及回焊熔接。缺點為0SP膜厚監控不易、不耐水、溶劑清洗及不 耐多次無鉛焊料回焊。2)化學鎳金(ENIG/ENAG)以化學反應方式將銅面上還 原或置換上鎳及金。其缺點為製程管控不易，磷(P)含量過多時會影響焊鍚 春 性，過少時會使鎳面易被鍍金液腐蝕而造成人聞色變的黑墊問題(Black Pad) ’因介面結合力量變弱而導致脫落。3)電鍍鎳金，以電鍍方式將銅層 鍍上鎳及金層。其缺點為需要導電線設計，線路設計layout較困難，並因 受限於製程能力關係無法縮少面積；另外影響最大的是金(Au)層較厚 (>0· 5um)在回焊時會擴散至焊鍚中造成IMC變脆(Brittle)，一般而言金在 鍚中佔的體積比愈大其物性就愈差。 【發明内容】 本卷月之主要目的在提供一種對錫球有高結合力的銲墊結構，主要基於現 有技術如 QSP、ENIG、ENAG、Ni/Au plating、Immersion Tin 等的優點下， 藉著接觸面積與結合力成正比的原理，額外增加了銲墊開口壁面上與鲜球 接觸的’進而達到在有限的空間裏增加焊點的接觸面積而提升接合強 度的目的。 本發明之次要目的在提供—種對锡球有高結合力的銲墊結構，藉著在防銲 6 1274412 阻劑層上施作暫時導電層時，由烊球面㈣他)將魏時所需的電流傳 入鲜整面(_ Pad Slde)，進♦在社綱_地方，例如： Bond fmger、capacity pad，而達到無導電線電鑛。 .基於上述目的，本發騎錫球有高結合力的銲墊結構，主要是使原本, 在線路層上的保護層延伸至銲塾開口内（由繞著保護層、線路層之防鲜^劑 層所構成麻銲阻劑層的壁面上。如此—來，在對銲_ ^内的鲜塾填入 錫球時，由於與錫球有直接接觸的保護層除了覆蓋在線路層的部分外，額 _外增加博墊開π壁面上的部分，藉著接觸面積與結合力成正比的原理， 而大幅提高銲墊對錫球的結合力。 關於本發明之優點與精神可以藉㈣下的發明詳述及所關式得到進一步 的瞭解。 【實施方式】 φ 與現有加強並減少介面合金共化物層（IMC)因老化而影響烊點結合力的技 術大多針對焊墊表面處理的方法進行改良，均與本發明朝結構方面來改善 有復大差異。在本發明中除考慮使用不同的表面處理方式外，本專利構想 著重於如何在有限的空間裏增加焊點的接觸面積而達到提升接合強度的目 ν 的。 具體而言，本發明對錫球有高結合力的銲墊結構，主要是使原本覆蓋在線 路層上的保護層延伸至銲塾開口内（由繞著保護層、線路層之防銲阻劑層所 構成）的防銲阻劑層的壁面上。如此’藉著接觸面積與結合力成正比的原 7 1274412 理’提高錫球和銲塾之間的結合力。但為了將〇sp、ENIG、E隊、隐u1274412 IX. Description of the invention: [Technical field to which the invention pertains] The present invention is directed to a type of pad, in particular to a pad structure having a high bonding force of a ball. [Prior Art] • In the trend of miniaturization of electronic products, the opening of the electronic contacts on the carrier board, such as the baU pad or the opening of the bump pad, and the filling welding The size of the cricket or bump of the pad is also getting smaller and smaller. For example, the pad width of the BGA has been reduced from lmm to 0.4mm' and even 〇·3mm, while the SM pad opening has been reduced from 350"m to 22〇//m, FlipChip soldering. The pad opening has also been reduced from ioovjjj to the design requirements of 8〇/^, etc. However, there is an unprecedented problem in the packaging process under the trend of miniaturization. Since the bonding strength between the solder ball and the pad is proportional to the contact area, As the size becomes smaller and smaller, the bonding strength between the solder ball φ and the pad also decreases as the contact area becomes smaller, which leads to easy peeling, pulling off and cracking after the packaging process is completed. When the phenomenon will make the electronic contact lose the connection function and open, so how to strengthen the bonding strength becomes a key point. In order to ensure that the above-mentioned falling off, pulling off and cracking will not occur, the bonding strength between the solder ball and the pad must be Passed test methods such as pull strength, chisel test, ball shear test, temperature storage and Drop Test, among which Nokia's Drop Test is the most stringent. Under the trend of green products such as RoHS, The sub-contact faces the need to use lead-free solder, causing the IR reflow temperature to rise from about 220 ° C to 245-260 ° C, and many of the surface treatments for the pad 5 1274412 are not Increasing the bonding strength between the solder balls and the solder pads is not suitable for multiple reflows. The main techniques for surface treatment are as follows: 1) 〇SP (〇rganic Solderability: Preservatives) protects the copper surface by chemical treatment to make the copper surface more resistant. The baking and reflow soldering in the packaging process • The disadvantage is that the 0SP film thickness monitoring is not easy, water resistance, solvent cleaning and resistance to multiple lead-free solder reflow. 2) Chemical nickel gold (ENIG/ENAG) with chemical reaction The method reduces or replaces nickel and gold on the copper surface. The disadvantage is that the process control is not easy, and the excessive content of phosphorus (P) will affect the spring quality of the soldering iron. When too little, the nickel surface is easily corroded by the gold plating liquid and cause human color to be smelled. The black pad problem (Black Pad) is caused by the weakening of the bonding strength of the interface. 3) Electroplating nickel gold, electroplating the copper layer with nickel and gold. The disadvantage is that it requires conductive wire design, circuit design layout More sleepy And because of the limitation of process capability, the area cannot be reduced; the most influential is that the gold (Au) layer is thicker (>0·5um) and will spread to the solder joint during reflow to cause the IMC to become brittle (Brittle). In general, the larger the volume ratio of gold in the crucible, the worse its physical properties. [Invention] The main purpose of this volume is to provide a pad structure with high bonding force to the solder ball, mainly based on the prior art. Under the advantages of QSP, ENIG, ENAG, Ni/Au plating, Immersion Tin, etc., by the principle that the contact area is proportional to the bonding force, the contact opening on the wall of the pad with the fresh ball is additionally increased, thereby achieving a limited space. Increase the joint area of the solder joint to enhance the joint strength. The secondary object of the present invention is to provide a pad structure having a high bonding force to a solder ball. When a temporary conductive layer is applied on the resist layer of the solder resist 6 1274412, the ball surface (4) will be used by Wei Shi. The current required is transmitted to the fresh surface (_ Pad Slde), and the ♦ is in the _ place, such as: Bond fmger, capacity pad, and reaches the non-conductive line. Based on the above purposes, the present invention has a high bonding force pad structure, which mainly causes the protective layer on the circuit layer to extend into the soldering opening (by the protective layer and the circuit layer) The layer formed on the wall of the solder resist layer. Thus, when the solder fillet is filled in the solder paste, the protective layer in direct contact with the solder ball is covered except for the portion of the circuit layer. The amount of _ outside increases the part of the π wall surface, and by the principle that the contact area is proportional to the bonding force, the bonding force of the solder pad to the solder ball is greatly improved. The advantages and spirit of the present invention can be borrowed under (4) The details of the invention and the related formula are further understood. [Embodiment] φ and the existing techniques for strengthening and reducing the interfacial alloy alloy layer (IMC) which affect the adhesion of the joint due to aging are mostly improved for the surface treatment of the soldering pad. Both of them are different from the structural improvement of the present invention. In addition to considering the use of different surface treatment methods in the present invention, the patent concept focuses on how to increase the contact area of the solder joints in a limited space. Specifically, the solder pad structure having high bonding force to the solder ball of the present invention mainly extends the protective layer originally covering the circuit layer into the solder fillet opening (by the protective layer) The surface of the solder resist layer formed by the solder resist layer of the circuit layer. Thus, by the contact area and the bonding force, the original 7 1274412 improves the bonding force between the solder ball and the solder bump. But in order to put 〇sp, ENIG, E team, hidden u
Pl_g、Ι·_如所提供的優點融入至本發明中，，因此本發明鲜整 結構主要是基於上述製程方賴外增加_些步驟，讓上述製程巾所形成的 保護層延伸而提高接觸面積。底下將以兩種保護層（―組為銅、鎳和金，另 一組為銅和抗氧化膜）’分別說明三種本發明對錫球有高結合力的辉塾結 象請參閱第㈣圖’第㈣圖為墓於本發明對錫球有高結合力的銲塾結 '構之第一實施示意圖。如第1Α圖所示，若希望對載板10上的線路層14(亦 即將填入錫球的銲墊)作保護時，一般僅會以如_方法在線路層Μ上依 剌Μ銅層16、鎳層18和金層19(亦即保護層），並以防鮮阻劑層㈣繞 者保遵層、線路層14而構成銲· 口 注意的是，由於載板、保 護層等的製作方法均屬習知技術，在此不加以累述，僅就本發明所提出的 銲墊結構作說明。 春但為了在錫球填入鋒塾開口時，增加錫球、銲塾之間的結合力，因此在本 七明㈣'結構中’會由覆蓋在線路層14的保護層延伸至銲墊開口内的防銲 阻劑層的壁面上，亦即會依序在防銲阻劑層的壁面上形成銅層Μ、錄層Μ 7 S 19(亦即保€層）。如此—來，會與錫球有直接接觸的保護層除了覆 八線路層14的部分外，本發明銲墊結構尚額外增加了銲墊開口壁面上的 ★圖斤不之俯視圖），因此藉著接觸面積與結合力成正比的原 理’而大巾礙高轉觸_結合力。 i閱第㈣圖’第2Α〜2β圖為基於本發明對錫球有高結合力的鲜塾結 8 1274412 構之弟一貫施不意圖。如第？A闰讲士 F1以人 弟2A圖所不，冋樣會在載板1〇上的線路層14上 形成保護層（銅層16、鎳層18和金層19),並以防鮮阻劑層a圍繞著保護 層、線路層14而構成銲墊開口。但是在本發明銲墊結構除了會在銲墊開口 壁面上形成保護層外，此保護層尚會由晴阻劑層12的壁面上延伸至防辉 阻劑層12的上表面，而形成環繞銲· 口的環狀外擴㈣。由㈣圖所 示之俯《，環狀外擴部2〇僅能觀察到金層19，是因為金層⑺遮蔽了銅 ㈣m 賴胁了覆蓋在線路 層14的部分外，本發明銲墊結構尚額外增加了銲师壁面上的部分、環 狀外擴部2Q，因此11著接觸面積與結合力叙_顧，W高鲜塾 對錫球的結合力。 請參閱請，第3嶋於本發賴球椒合蝴墊結構之第三 貫施不意圖。如第3圖所示，在第2β圖所示之環狀外擴部2〇令使其具有 缺口部’且缺口部填入防銲阻劑層12。若此缺口部在數量上達到一定程度 時，便會使環狀外擴部2G形成如花瓣狀或是爪子狀(咖），以更進一步 =球有更高騎合力。此外，若故意造成環狀外擴㈣細的附著力 此顧入錫球後進行轉程序時，焊鍚因内聚力及焊鍚回流炼濕 m H觸兩種糊訂，會將保護層的金屬含在焊射達到嵌 入的效果。 =㈣銅峨靖顿，嶋她晴構蝴上大致 差/、不大，不過仍簡單說明之。 明對錫球有高結合力的銲墊結 請參閱第4A〜4B圖’第4A，為基於本發 構之第四實施示意圖 10上的線Pl_g, Ι·_ as the advantages provided are incorporated in the present invention, and therefore the fresh structure of the present invention is mainly based on the addition of the above-mentioned process steps to allow the protective layer formed by the process towel to be extended to increase the contact area. . Under the two protective layers ("group is copper, nickel and gold, the other group is copper and anti-oxidation film") respectively, three kinds of stibnites with high binding force to the solder balls of the present invention are described. Please refer to the figure (4). The 'fourth figure is a first implementation diagram of the structure of the bead joint having a high bonding force to the solder ball of the present invention. As shown in the first figure, if it is desired to protect the circuit layer 14 on the carrier 10 (that is, the pad to be filled with the solder ball), the copper layer is generally only supported on the circuit layer by the method. 16. The nickel layer 18 and the gold layer 19 (i.e., the protective layer) are formed by the anti-friction agent layer (4) around the layer and the circuit layer 14 to form a solder joint. Note that due to the carrier layer, the protective layer, etc. The manufacturing method is a conventional technique, and will not be described here. Only the structure of the pad proposed by the present invention will be described. In spring, in order to fill the front edge of the solder ball, the bonding force between the solder ball and the soldering iron is increased. Therefore, in the structure of the seventh (four) 'structure, the protective layer covering the circuit layer 14 extends to the opening of the pad. On the wall surface of the solder resist layer, a copper layer Μ and a recording layer S 7 S 19 (that is, a layer) are formed on the wall surface of the solder resist layer. In this way, in addition to the portion of the protective layer provided in direct contact with the solder ball, the pad structure of the present invention additionally adds a top view of the wall surface of the pad opening, so The contact area is proportional to the binding force' and the large towel hinders the high-touch _ binding force. i read the (fourth) map '2nd ~ 2β figure is based on the present invention for the high binding force of the solder ball of the fresh knot 8 1274412 structure of the brother has not been intended. As the first? A 闰 士 F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F F The layer a surrounds the protective layer and the wiring layer 14 to form a pad opening. However, in addition to forming a protective layer on the opening wall surface of the pad, the protective layer of the present invention extends from the wall surface of the resist layer 12 to the upper surface of the anti-grein resist layer 12 to form a surrounding solder. The ring of the mouth is expanded (4). According to the figure shown in (4), the gold layer 19 can only be observed in the annular outer portion 2, because the gold layer (7) shields the copper (four) m and covers the portion of the circuit layer 14, the pad structure of the present invention. The part of the welder's wall and the annular expansion part 2Q are additionally added. Therefore, the contact area and the combined force are used to describe the bonding force of the high fresh enamel to the solder ball. Please refer to the third section of the structure of the ball and the butterfly pad. As shown in Fig. 3, the annular expanded portion 2 shown in Fig. 2 has a notch portion and the notched portion is filled with the solder resist layer 12. If the number of the notches is reached to a certain extent, the annular flared portion 2G is formed like a petal shape or a claw shape, so that the ball has a higher riding force. In addition, if the adhesion of the ring is deliberately caused by the (4) fine adhesion, the weld bead is transferred to the solder ball after the solder ball is transferred, and the weld metal will be covered by the cohesive force and the solder reflow methane. The soldering shot achieves the embedded effect. = (4) The copper 峨 峨 顿 嶋 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , A solder pad having a high bonding force to the solder ball, see FIG. 4A to FIG. 4B, FIG. 4A, which is a line on the fourth embodiment based on the fourth embodiment of the present invention.
1274412 如第4A圖所示，以如0Sp等方法在載板 路層14上形成保護層（銅層4()和抗氧化膜42)，並以防鲜阻劑層η圍繞著 保護層、線路層14而構成鋒墊開口。但是在本發明鲜塾結構除曰了會如第^ 圖所示在銲_ 口壁面上形成練層外，聽麟尚會由防銲喃声㈣ 壁面上延伸至防銲阻劑層12的上表面，而形成環繞銲墊開口的環狀外擴部 44 ’如第4Β圖所示。環狀外擴部44也可如2β圖所示之環狀外擴部卻令 使其具有缺口部，也擁有同樣的效果。 此外，若同時考慮暫時導電層（temperate conduct —π，卿與外 擴部20時，亦即在防銲阻劑層12上施作暫時導電層時，可由焊球面(_ side)將電鑛—所需的電流傳入銲塾面(匕卿㈣^如），進而傳入在辞塾 面上需要電錄的地方，例如：Bond finger、capacity _，而達到無導電 線電鍍的目的。與以往無導電線電鍍的不同之處，本發明可在以成線路 層14、防銲阻劑層12之後才進行電鍍保護層，因此在防銲阻劑層U之下 不會有如金層19的存在。由於在防銲阻劑層12下沒有金層19，就不會因 防銲阻劑層12對金層19 _著力不佳所衍生出的問題。 藉由以上較佳具體實施例之詳述，係希望能更加清楚描述本發明之特徵與 精神，而並非以上述所揭露的較佳具體實施例來對本發明之範疇加以限 制。相反地，其目的是希望能涵蓋各種改變及具相等性的安排於本發明所 欲申請之專利範圍的範疇内。 1274412 【圊式簡單說明】 第 的銲墊結構之第 1A〜1B圖為基於本發明鈸 ΐ踢球有rsj結合力 一實施示意圖。1274412 As shown in FIG. 4A, a protective layer (copper layer 4() and an anti-oxidation film 42) is formed on the carrier layer 14 by a method such as 0Sp, and the protective layer and the line are surrounded by the anti-friction agent layer η. Layer 14 constitutes a front pad opening. However, in addition to the formation of the layer of the fresh enamel structure of the present invention, as shown in Fig. 2, the lining of the enamel layer will be extended from the wall of the solder mask (4) to the solder resist layer 12. The surface is formed to form an annular flared portion 44' surrounding the opening of the pad as shown in Fig. 4. The annular outer expansion portion 44 may have a notch portion as in the annular outer expansion portion shown in Fig. 2β, and has the same effect. In addition, if a temporary conductive layer (temporate conduct — π, and the outer expanded portion 20 is also considered, that is, when the temporary conductive layer is applied on the solder resist layer 12, the electric ore may be transferred from the solder ball surface (_side). The required current is transmitted to the soldering surface (匕卿(四)^如), and then it is transmitted to the place where the transcript is needed, such as Bond finger and capacity _, to achieve the purpose of non-conductive plating. The difference between the electroless plating and the plating can be performed after the wiring layer 14 and the solder resist layer 12 are formed, so that there is no existence of the gold layer 19 under the solder resist layer U. Since there is no gold layer 19 under the solder resist layer 12, there is no problem arising from the poor resistance of the solder resist layer 12 to the gold layer 19. By the above detailed description of the preferred embodiment It is intended that the present invention be limited and not limited by the preferred embodiments disclosed herein. Instead, the invention is intended to cover various modifications and equivalents. The scope of the patent scope to be applied for by the present invention 1274412 [Simple description of the 圊] The 1A to 1B of the first pad structure is a schematic diagram of the rsj binding force based on the 钹 ΐ kicking ball according to the present invention.
之第二實施示意圖。 二實施示意圖。 之第四實施示意圖。A second implementation schematic. Second implementation diagram. A fourth implementation schematic.
第2㈣圖絲於本翻對錫财高結合力的鲜塾結構 D圖為胁本發_财有高結合力的料結構之第 第4A〜4B _基於本發日靖锡球有高結合力觸塾結構 【主要元件符號說明】 10载板 12防銲阻劑層 U線路層 16、40銅層 18鎳層 W金層 20、44環狀外擴部 42抗氧化膜The 2nd (4) Figure in this pair of 财 财 高 高 高 结合 塾 塾 为 胁 胁 胁 胁 胁 胁 胁 胁 胁 胁 胁 _ _ _ _ _ _ _ _ _ _ _ _ _ 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖 靖Contact structure [main component symbol description] 10 carrier 12 solder resist layer U circuit layer 16, 40 copper layer 18 nickel layer W gold layer 20, 44 annular expansion portion 42 anti-oxidation film