200927357 九、發明說明： 【發明所屬之技術領域】 本發明係關於Sn-Ag-Cu系之無鉛焊料，其係Ag含量 少之無鉛焊料。 【先前技術】 以電子機器爲首的金靥彼此之接合中，已知相當有用 之硬焊料作爲焊料。以往係使用Sn-Pb之共晶焊料，具有 φ 優異之特性。但是，使用含Pb之焊料而成的製品在廢棄 後，若與pH高之酸性雨接觸，由於Pb會溶出而被視爲牽 涉到環境污染。 1 因此，在世界性規模推廣沒有Pb之無鉛焊料的使用， 在部分區域甚至有地區成立了在電氣製品中不能使用鉛之 法規。 隨之而來，無鉛焊料之開發亦在世界性規模進行著。 例如，Sn-3Ag-3Bi 系、Sn-3.5Ag-2.5Bi-2.5In 系、Sn-58Bi ❹ 系、Sn-9Zn系等合金系。然而，此等合金系焊料係各自在 延展性、成本、高溫強度、抗氧化性等項目仍有實用上之 課題。 爲了能夠支持此種實用性，焊料必須解決許多評價項 目。現在，綜合性地考慮此種評價項目時，向來認爲做爲 標準無鉛焊料者係Sn-3Ag-0.5Cu系的焊料。 但是，Sn-3Ag-0.5Cu系的焊料亦有問題點。尤其是在 熱疲勞特性等可靠性上有許多欲解決之處，因此不能使用 在汽車搭載用及半導體封包用。 200927357 認爲引起Sn-3Ag-0.5Cu系的焊料之可靠性問題的原因 係如下。在Sn-3Ag-0.5Cu系的焊料，Ag的固溶量即使在使 用臨界溫度之125 °C亦爲0.01質量％以下，稱爲分散有 Ag3Sn之分散強化型合金。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Sn-Ag-Cu-based lead-free solder which is a lead-free solder having a small Ag content. [Prior Art] In the joining of gold enamels such as electronic machines, a useful hard solder is known as a solder. In the past, a eutectic solder using Sn-Pb was used, and it has excellent characteristics of φ. However, when a product made of Pb-containing solder is used, it is considered to be involved in environmental pollution because it is dissolved in acidic rain with a high pH. 1 Therefore, the use of lead-free solders without Pb has been promoted on a worldwide scale, and regulations for the inability to use lead in electrical products have been established in some regions and even regions. As a result, the development of lead-free solders has also been carried out on a worldwide scale. For example, an alloy system such as a Sn-3Ag-3Bi system, a Sn-3.5Ag-2.5Bi-2.5In system, a Sn-58Bi system, or a Sn-9Zn system. However, these alloy-based solder systems still have practical problems in terms of ductility, cost, high-temperature strength, and oxidation resistance. In order to support this practicality, solder must address many evaluation items. Now, when considering such an evaluation item comprehensively, it is considered to be a solder of the Sn-3Ag-0.5Cu system as a standard lead-free solder. However, Sn-3Ag-0.5Cu solder is also problematic. In particular, there are many problems to be solved in terms of reliability such as thermal fatigue characteristics, and therefore it cannot be used for automotive mounting and semiconductor packaging. 200927357 The reason for the reliability of the solder causing the Sn-3Ag-0.5Cu system is as follows. In the solder of the Sn-3Ag-0.5Cu type, the solid solution amount of Ag is 0.01% by mass or less even at a critical temperature of 125 ° C, and is called a dispersion-strengthened alloy in which Ag3Sn is dispersed.
Sn-3Ag-0.5Cu系焊料的強度係藉由該已分散之ιμιη以 下的微細Agdn粒子而達成。但是，經分散之Ag3Sn粒子 若粗大化時，會對蠕變強度及熱疲勞特性產生不良影響。 汽車搭載用或半導體封包用之焊料暴露於高溫環境的 情形爲多。在髙溫狀態，原子的擴散速度上升，可說是容 易引起AgsSn粒子之粗大化的環境。假如粗大的Ag3Sn粒 子形成時，從粗大粒子的部分龜裂會優先地產生.蔓延而破 損。認爲此係Sn-3Ag-0.5Cu系的焊料中可靠性問題的原因。 解決該問題而得到高可靠性中，有抑制A g 3 S η粒子之 粗大化的必要。作爲其對策之一，爲減低焊料中Ag的含量。The strength of the Sn-3Ag-0.5Cu-based solder is achieved by the fine Agdn particles below the dispersed ιμιη. However, when the dispersed Ag3Sn particles are coarsened, the creep strength and thermal fatigue characteristics are adversely affected. Solder for automotive mounting or semiconductor packaging is exposed to high temperatures. In the state of enthalpy, the diffusion rate of atoms increases, which is an environment that easily causes coarsening of AgsSn particles. If coarse Ag3Sn particles are formed, part of the cracks from the coarse particles will preferentially occur, spread and break. This is considered to be a cause of reliability problems in the solder of the Sn-3Ag-0.5Cu system. In order to solve this problem and obtain high reliability, it is necessary to suppress the coarsening of the A g 3 S η particles. As one of the countermeasures, the content of Ag in the solder is reduced.
Ag的減低亦與降低焊料的成本相關，爲所期待之方 向。但是，由於亦同時減低Ag3S η之微細粒子，亦與自體 強度的下降相關。因此，考慮添加使強度提升之元素來代 替所減少之Ag。此係Sn-Ag-Cu-X(X爲添加元素）系之4元 系的焊料。 關於4元系的焊料，已有數個報告。例如專利文獻1 揭示爲了抑制在焊料接合後固化之際晶鬚（whisker)的發 生’使用Zn作爲假防蝕部而成的焊料。在其變化中，有 Sn-Ag-Cu-Zn系的焊料之揭示。 在專利文獻2，於Sn-Ag-Cu系的焊料，由於在接合部 200927357 層狀地形成金屬間化合物，爲了解決落下衝撃 弱之課題，而揭示含有從Mg、Y、La、Ce、Pr Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu 之1種元素當作第4元素之4元系焊料。進一 於在Sn-Ag-Cu中添加Mg、Y、La之3種類而成 焊料，添加選自 Ni、Fe、Al、Sb、Bi、P、Zn、 當作第7元素之焊料。 在專利文獻3，爲使Sn-Zn系的焊料之抗拉 探討報告經添加Ag與Cu之組成。其中揭示了 S 組成之焊料。 [專利文獻1]特開2006_28949 3號公報 [專利文獻2]特開2005-254298號公報 [專利文獻3]特開平09-94687號公報 【發明内容】 發明所欲解決之課顆 在專利文獻1、2, Ag的比率爲1.〇質量％〜 Ag的含量仍然爲多，藉由所揭示之組成無法避 子粗大化時強度的降低。 又，在專利文獻3,由於基本上係使Sn-Zn 械強度提升，係含有7〜9質量％之Zn。若Zn才 有多於1質量％，則抗氧化性惡化。亦即，在此 明，在Sn-Ag-Cu系的焊料中，雖然減少了 Ag 並非解決了確保強度及可靠性之課題。 解決課顆之手段 時的強度爲 、Nd、Pm、 之中所選出 步，揭示對 的6元系的 In ' Pt ' Pd 強度提高， n-Zn-Ag-Cu 3.0質量％， 免AgsSn粒 系焊料之機 I對於Sn含 所提議之發 的含量，但 200927357 別是爲了解 缺陷能量來 考慮了藉由 溶原子之強 溫環境下會 可靠性之課 題係期望利 由固溶原子 之焊料的強 層缺陷能量 重Sn-X(X爲 測強度。其 最具強度提 於藉由固溶 以遠小於7 反覆探討硏 及可靠性之 :即，本發明 較佳爲1.1 量％之C u、 L無鉛焊料。 本發明係爲了解決如此課題所想到者，特 決該課題，根據由第一原理計算所預測之積層 進行強度預測。在焊料合金的強度提升方面， Ag3Sn粒子等第二相粒子之強化方法與藉由固 化方法。然而，藉由第二相粒子之強化法在高 有粒子粗大化的危險性，無法適當解決確保 題。於是，確保焊料合金的強度及可靠性之課 用藉由固溶原子之強化方法。發明人等針對藉 之強化的原因反覆調查，結果確認了固溶合金 度係與依照固溶原子的種類及濃度所決定之積 有極大相關。因此藉由第一原理計算，算出數I 添加元素）固溶2元合金的積層缺陷能量，且預 結果，確認使用藉由固溶原子之強化方法時， 升效果之添加元素爲Zn。The reduction in Ag is also related to the cost of reducing solder, which is the desired direction. However, since the fine particles of Ag3S η are also reduced at the same time, it is also associated with a decrease in the self-strength. Therefore, consider adding an element that enhances the strength to replace the reduced Ag. This is a four-component solder of Sn-Ag-Cu-X (X is an additive element). There have been several reports on the solder of the 4-element system. For example, Patent Document 1 discloses a solder in which Zn is used as a pseudo-corrosion portion in order to suppress the occurrence of whiskers during curing after solder bonding. Among them, there is a disclosure of a Sn-Ag-Cu-Zn-based solder. In Patent Document 2, in the Sn-Ag-Cu-based solder, an intermetallic compound is formed in a layered manner at the joint portion 200927357, and in order to solve the problem of falling and weakening, it is revealed that Mg, Y, La, Ce, and Pr Sm are contained. One element of Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu is used as the fourth element of the fourth element. Further, a solder of three types of Mg, Y, and La is added to Sn-Ag-Cu, and a solder selected from the group consisting of Ni, Fe, Al, Sb, Bi, P, and Zn is used as the seventh element. In Patent Document 3, in order to make the tensile analysis of the Sn-Zn-based solder, a composition of Ag and Cu is added. It reveals the solder composed of S. [Patent Document 1] JP-A-2005-254298 [Patent Document 3] JP-A-H09-94687A SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION In Patent Document 1 2, Ag ratio is 1. 〇 mass% ~ Ag content is still much, by the disclosed composition can not avoid the coarsening of the strength. Further, in Patent Document 3, since the Sn-Zn mechanical strength is basically improved, it contains 7 to 9 mass% of Zn. If Zn is more than 1% by mass, the oxidation resistance is deteriorated. That is to say, in the Sn-Ag-Cu-based solder, the reduction of Ag does not solve the problem of ensuring strength and reliability. The strength of the method of solving the class is Nd, Pm, and the selected step, revealing the In 'Pt ' Pd intensity of the 6-member system, n-Zn-Ag-Cu 3.0% by mass, free of AgsSn granules The solder machine I contains the content of the proposed hair for Sn, but 200927357 is not only for understanding the defect energy, but also the reliability of the solution in the strong temperature environment of the dissolved atom. The layer defect energy weight is Sn-X (X is the measured intensity. The most strength is proposed to discuss the enthalpy and reliability by solid solution at a distance of less than 7: that is, the present invention preferably has 1.1% of C u, L lead-free In order to solve such a problem, the present invention solves the problem and predicts the strength based on the layer predicted by the first principle calculation. The method of strengthening the second phase particles such as Ag3Sn particles in terms of improving the strength of the solder alloy And by the solidification method. However, the reinforcement of the second phase particles has a high risk of coarsening of the particles, and the problem of ensuring the strength and reliability of the solder alloy is solved by solid solution. original The inventors have repeatedly investigated the reasons for the reinforcement, and as a result, it has been confirmed that the solid solution alloy system is highly correlated with the product determined by the type and concentration of the solid solution atom. Therefore, the first principle calculation is used to calculate The number I added element) the layered defect energy of the solid solution of the ternary alloy, and it was confirmed that when the strengthening method by solid solution atoms was used, the additive element of the liter effect was Zn.
Zn對於Sn的最大固溶量爲0.4質量％，由 原子之強化僅已固溶之Zn原子爲有效，Zn係 〜9質量％的量之添加而可確保強度。再者， 究，結果發現減少Ag的含量同時確保強度 Sn-Ag-Cu-Zn之4元合金，而完成了本發明。亦 係提供一種以質量比率計，〇.〇1〜1.5質量％、 質量％、更佳爲1.0質量％之Ag、〇.〇1〜1.0質 0.1〜1.0質量％之Zn及剩餘部分爲Sn所構成λ： 發明效果 由於本發明係在Sn-Ag-Cu系的焊料中’將Ag的含量 200927357 減低至0.01〜1.0質量％，故可避免因AgsSn之粗大化導致 強度可靠性的降低。再者，針對因Ag本身減少所致之強度 降低，使含有Zn而補償。也就是說，本發明之Sn-Ag-Cu.Zn 系的焊料能夠保持Sn-3Ag-0.5Cu組成之焊料的強度，同時 減少Ag而得可靠性優良之焊料。 【實施方式】 實施發明之最佳形態 本發明的焊料基本上爲Sn-Ag-Cu系之組成的焊料，Ag 的含量與Sn-3Ag-0.5Cu之組成相比爲較低。在本發明的焊 料，八2的含量爲0.01〜1.5質量％、較佳爲1.1質量％、更 佳爲 1.0質量％之範圍。如前所述，本發明爲確保 Sn-3Ag-0.5Cu系的焊料之可靠性，係根據減低Ag的含量之 技術性思考。 但是，若完全沒有Ag時，無法基於AgsSn微粒子的存 在而獲得強度。而且，完全沒有Ag存在之組成時，光澤從 焊料之表面狀態消失。經使用焊料之製品的情況下，在能 否接著的檢査上大多以焊料的表面光澤來判斷。因此，完 全沒有Ag的情況爲不佳。本發明人鑽硏探討，結果發現若 Ag存在0.01質量％以上，則可得表面光澤。 又，若含有多於1.5質量％之Ag時，拉伸度係惡化。 此係與可靠性之降低相關。 接著，關於Cu係含有0.01〜1.0質量％。若Cu的含量 超過1.0質量％而存在時，焊料的熔點上升，塗抹焊料時， 有對封裝構件造成熱傷害之問題。 200927357 此外，Cu的含量比0.01質量％低時 即電子電路之銅線的Cu在焊料中擴散。 象，銅線爲數十左右之細銅線時， 銅線消失的情形，與接合不良的發生相 Zn係用以補償減低Ag含量時的 素。Zn係用以補償因Ag的減低所致之 少爲0.1質量％。另一方面，Zn的含量 φ 説明之抗氧化性惡化外，濕潤性亦會惡 接合強度降低。 又，本發明之Sn-Ag-Cu-Zn系的焊 由 Mg、Al、P、Ti、Mn、Fe、Co、Ni、 Au、Bi構成之群組所選出之至少1種元 再者，其中含有In與Bi之總量爲三 降低焊料的熔點。另一方面，若含有比 料會變脆。 Q 此外，亦可含有至多0.5質量％之由 之至少1種元素。此等元素係在熔融焊 氧化物生成自由能比焊料之主構成成分 此，在熔融溫度範圍中，比Sn更優先: 的氧化，具有提升焊料表面之光澤的效 有此數値以上之此等元素時，會導致濕 焊料後表面之粗糙。 此外，亦可含有至多0.5質量％之白 出之至少1種元素。此等元素之添加係 ，塗抹焊料的對象 此係稱爲銅侵餓現 在塗抹焊料時亦有 關。 強度降低所含的元 強度降低，必須至 爲多時，除了如已 化，而封裝構件的 料亦可進一步含有 Ga、Ge、Mo、In' 素。 g多3質量％，能夠 此數値更多時，焊 I P、Ga、Ge所選出 料之溫度範圍中， 即S η小的元素❶因 地氧化，而抑制Sn 果。另一方面，含 潤性之惡化及塗抹 自Fe、Co、Au所選 :具有減低焊勺勺口 -10- 200927357 侵蝕之效果。然而，添加此數値以上之量會成爲濕潤 降低與熔點之上升的原因，因而不佳。 此外，亦可含有至多1.0質量％之由Mg、A卜Ti、 Ni、Mo所選出之至少1種元素》此等元素之添加係右 的提升上具有效果。另一方面，由於此等元素對Sn焉 溶或固溶量極少，故添加此數値以上的量會招致組縛 出物量的增加，而拉伸度顯著減少。 接著，針對本發明之Sn-Ag-Cu-Zn系的焊料就養 實施例加以詳細説明。又，對於實施例之各評價項目 評價項目與判斷基準係如下所示β 關於本發明之Sn-Ag-Cu-Zn系之實施例以及與突 之比較例之組成及各評價項目的評價結果示於表 5。以下根據此等表格說明實施結果。 ❹ 丨性之 Μη ' 三強度 I不固 I中析 f際之 丨，其 〔相對 1〜表 -11- 200927357 [表1] 組成 實測組成 外觀 展開率(％) Ag Cu Zn Ag Cu Zn 判定 判定 結果 實施例1 1.0 0.7 1.0 1.102 0.684 1.071 △ 〇 74 實施例2 1.0 0.7 0.7 0.985 0.725 0.753 〇 〇 75 實施例3 1.0 0.3 1.0 1.011 0.297 1.082 〇 〇 75 實施例4 1.0 0.3 0.7 0.998 0.298 0.692 〇 〇 75 實施例5 1.0 0.1 0.7 0.997 0.105 0.691 〇 〇 76 實施例6 1.0 0.1 0.4 0.991 0.103 0.404 〇 〇 76 實施例7 1.0 0.1 0.1 1.070 0.115 0.113 〇 〇 76 實施例8 0.3 0.5 0.4 0.292 0.512 0.388 Δ 〇 74 實施例9 0.01 1.0 1.0 0.011 1.028 1.023 Δ 〇 75 實施例10 0.01 0.01 0.4 0.009 0.010 0.413 Δ 〇 75 實施例11 0.01 0.01 0.1 0.011 0.009 0.099 〇 〇 76 比較例1 3.0 0.5 0.4 3.040 0.501 0.372 〇 〇 74 比較例2 3.0 0.5 0.0 3.000 0.462 - 〇 〇 76 比較例3 1.0 0.5 0.0 1.018 0.521 - 〇 〇 75 比較例4 0.3 0.7 0.0 0.312 0.693 墨 〇 〇 75 比較例5 0.3 0.5 1.5 0.293 0.490 1.523 Δ X 68 比較例6 0.01 2.0 0.01 0.009 1.987 0.012 〇 〇 75 比較例7 0.005 0.1 0.1 0.006 0.098 0.107 X 〇 76 比較例8 0.0 0.0 0.0 - - X 〇 79The maximum solid solution amount of Zn to Sn is 0.4% by mass, and only Zn atoms which have been solid-solved by atomic strengthening are effective, and the addition of Zn to 9% by mass ensures the strength. Further, as a result, it was found that the content of Ag was reduced while securing a 4-membered alloy of Sn-Ag-Cu-Zn, and the present invention was completed. Also provided is a mass ratio of 〇.〇1 to 1.5% by mass, mass%, more preferably 1.0% by mass of Ag, 〇.〇1 to 1.0 mass 0.1 to 1.0% by mass of Zn and the remainder being Sn In the Sn-Ag-Cu-based solder, the Ag content 200927357 is reduced to 0.01 to 1.0% by mass, so that the reduction in strength reliability due to coarsening of AgsSn can be avoided. Further, the strength due to the decrease in Ag itself is lowered to compensate for the inclusion of Zn. In other words, the Sn-Ag-Cu.Zn-based solder of the present invention can maintain the strength of the solder of the Sn-3Ag-0.5Cu composition and at the same time reduce the Ag to obtain a solder having excellent reliability. [Embodiment] BEST MODE FOR CARRYING OUT THE INVENTION The solder of the present invention is basically a Sn-Ag-Cu-based solder, and the content of Ag is lower than that of Sn-3Ag-0.5Cu. In the solder of the present invention, the content of 八2 is in the range of 0.01 to 1.5% by mass, preferably 1.1% by mass, and more preferably 1.0% by mass. As described above, the present invention is based on the technical consideration of reducing the content of Ag in order to secure the reliability of the Sn-3Ag-0.5Cu-based solder. However, if Ag is not present at all, the strength cannot be obtained based on the presence of AgsSn fine particles. Moreover, when there is no composition in which Ag is present, the gloss disappears from the surface state of the solder. In the case of a product using solder, it is often judged by the surface gloss of the solder in the subsequent inspection. Therefore, the situation in which there is no Ag at all is not good. As a result of investigation by the inventors of the present invention, it has been found that if Ag is present in an amount of 0.01% by mass or more, surface gloss can be obtained. Further, when more than 1.5% by mass of Ag is contained, the degree of stretching is deteriorated. This is related to the reduction in reliability. Next, the Cu system is contained in an amount of 0.01 to 1.0% by mass. When the content of Cu exceeds 1.0% by mass, the melting point of the solder rises, and when the solder is applied, there is a problem of thermal damage to the package member. 200927357 Further, when the content of Cu is lower than 0.01% by mass, Cu of the copper wire of the electronic circuit diffuses in the solder. For example, when the copper wire is a thin copper wire of several tens of degrees, the copper wire disappears, and the Zn is used to compensate for the deterioration of the Ag content. The Zn system is used to compensate for the decrease of Ag by 0.1% by mass. On the other hand, the Zn content φ indicates that the oxidation resistance is deteriorated, and the wettability also deteriorates the joint strength. Further, the Sn-Ag-Cu-Zn system of the present invention is made of at least one selected from the group consisting of Mg, Al, P, Ti, Mn, Fe, Co, Ni, Au, and Bi, wherein The total amount of In and Bi is three to lower the melting point of the solder. On the other hand, if it contains a specific material, it will become brittle. Further, it may contain at least one element of at most 0.5% by mass. These elements are more effective than the main constituents of the solder in the molten solder oxide formation, and are more preferential than Sn in the melting temperature range: the effect of improving the gloss of the solder surface is more than this. When the element is used, it will cause the surface of the wet solder to be rough. Further, it may contain at least one element of up to 0.5% by mass of white. The addition of these elements, the object of soldering This is known as copper intrusion and is also relevant when soldering. The strength of the element contained in the strength reduction is lowered, and it must be for a long time, except that the material of the package member may further contain Ga, Ge, Mo, In'. g is more than 3% by mass, and when the number is more than ,, the temperature range of the selected output of the electrode I P, Ga, and Ge, that is, the element having a small S η is oxidized by the ground, and the Sn is suppressed. On the other hand, the deterioration of the moisture content and the application of Fe, Co, and Au are selected: it has the effect of reducing the erosion of the spoon spoon -10- 200927357. However, the addition of this amount or more will cause a decrease in wetting and an increase in melting point, and thus is not preferable. Further, it may contain at most 1.0% by mass of at least one element selected from Mg, A, Ti, Ni, and Mo. The addition of these elements has an effect on the right lift. On the other hand, since these elements have a very small amount of Sn solute or solid solution, the addition of this amount or more causes an increase in the amount of bound components, and the degree of stretching is remarkably reduced. Next, the Sn-Ag-Cu-Zn-based solder of the present invention will be described in detail with reference to examples. In addition, the evaluation items and the judgment criteria of the respective evaluation items of the examples are as follows. β The composition of the Sn-Ag-Cu-Zn system of the present invention, the composition of the comparative example, and the evaluation results of the respective evaluation items are shown. In Table 5. The results of the implementation are described below in accordance with these tables. ❹ 丨 Μ ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' Results Example 1 1.0 0.7 1.0 1.102 0.684 1.071 △ 〇 74 Example 2 1.0 0.7 0.7 0.985 0.725 0.753 〇〇75 Example 3 1.0 0.3 1.0 1.011 0.297 1.082 〇〇75 Example 4 1.0 0.3 0.7 0.998 0.298 0.692 〇〇75 Implementation Example 5 1.0 0.1 0.7 0.997 0.105 0.691 〇〇76 Example 6 1.0 0.1 0.4 0.991 0.103 0.404 〇〇76 Example 7 1.0 0.1 0.1 1.070 0.115 0.113 〇〇76 Example 8 0.3 0.5 0.4 0.292 0.512 0.388 Δ 〇 74 Example 9 0.01 1.0 1.0 0.011 1.028 1.023 Δ 〇75 Example 10 0.01 0.01 0.4 0.009 0.010 0.413 Δ 〇75 Example 11 0.01 0.01 0.1 0.011 0.009 0.099 〇〇76 Comparative Example 1 3.0 0.5 0.4 3.040 0.501 0.372 〇〇74 Comparative Example 2 3.0 0.5 0.0 3.000 0.462 - 〇〇76 Comparative Example 3 1.0 0.5 0.0 1.018 0.521 - 〇〇75 Comparative Example 4 0.3 0.7 0.0 0.312 0.693 Ink 〇〇 75 Comparative Example 5 0.3 0.5 1.5 0.293 0.490 1.523 Δ X 68 Comparative Example 6 0.01 2.0 0.01 0.009 1.987 0.012 〇 〇 75 Comparative Example 7 0.005 0.1 0.1 0.006 0.098 0.107 X 〇 76 Comparative Example 8 0.0 0.0 0.0 - - X 〇 79
-12- 200927357 [表2] 室溜 (M L強度 Pa) 室溫拉伸度 (%) 高溫強度 (MPa) 高溫拉伸度 (%) 熔點(。〇 判定 結果 判定 結果 判定 結果 判定 結果 判定 固相線 液相線 實施例1 〇 34.4 〇 65 〇 20.4 〇 53 〇 216 223 實施例2 〇 39.2 〇 61 〇 19.2 〇 74 〇 215 222 實施例3 〇 42.3 〇 57 〇 19.6 〇 76 〇 216 222 實施例4 〇 37.8 〇 68 〇 18.1 〇 67 〇 216 222 實施例5 〇 38.7 〇 63 〇 17.7 〇 62 〇 216 224 實施例6 〇 33.8 〇 52 〇 17.2 〇 59 〇 216 226 實施例7 〇 33.6 〇 53 〇 16.8 〇 54 〇 217 227 實施例8 〇 35.8 〇 63 〇 17.9 〇 55 〇 215 226 實施例9 〇 40.6 〇 60 〇 20.3 〇 50 〇 226 227 實施例10 〇 34.4 〇 64 〇 17.2 〇 115 〇 229 230 實施例11 〇 30.4 〇 68 〇 15.2 〇 57 〇 230 231 比較例1 〇 47.8 X 49 〇 22.0 X 46 〇 215 218 比較例2 〇 39.4 〇 56 〇 18.3 〇 61 〇 217 220 比較例3 X 18.4 〇 77 X 9.2 〇 65 〇 217 226 比較例4 X 25.3 〇 75 X 6.1 〇 60 〇 217 226 比較例5 〇 43.6 〇 50 〇 21.8 〇 52 〇 220 222 比較例6 - - - - - - - - X 217 287 比較例7 X 27.1 〇 68 X 13.5 〇 59 〇 229 230 比較例8 X 15.2 〇 96 X 4.2 〇 88 X 232' [表3] 高雛置時間 200h 500h 1000h 高溫 (M 強度 Pa) 高溫拉伸度 (%) 高溫 (M 強度 Pa) 高溫拉伸度 (%) 高溫 (M 強度 Pa) 高溫拉伸度 (%) 判定 結果 判定 結果 判定 結果 判定 結果 判定 結果 判定 結果 實施例1 〇 15.4 〇 55 〇 14.3 〇 63 〇 13.7 〇 73 實施例2 〇 18.0 〇 61 〇 17.9 〇 70 〇 16.7 〇 67 實施例3 〇 19.0 〇 64 〇 19.1 〇 66 〇 18.4 〇 61 實施例4 〇 17.5 〇 67 〇 17.1 〇 62 〇 17.0 〇 72 實施例5 〇 16.5 〇 60 〇 17.8 〇 68 〇 18.4 〇 65 實施例6 〇 15.0 〇 56 〇 16.3 〇 66 〇 15.0 〇 59 比較例2 〇 17.2 〇 55 〇 15.4 〇 60 〇 12.8 〇 70 -13- 200927357 [表4] 拉拔強度(N) 破損形態測定 高溫放置時間 高謙置時間 判 定 Oh 200h 500h 1000h 判 定 Oh 200h 500h lOOOh 結 果 結 果 結 果 結果 結果 結果 結果 結果 實 施 例1 〇 11.8 11.2 10.3 7.0 〇 D:12.5% E:87.5% E:100% E:100% E:100% 實 施 例2 〇 12.9 11.5 9.9 7.9 〇 B:100% B:87.5% E:12.5% B:50% E:50% E:100% 實 施 例3 〇 12.1 11.8 11.2 8.1 〇 D:12.5% E:87.5% E:100% E:100% E:100% 實 施 例4 〇 11.1 11.1 11.0 8.5 〇 B:50% E:50% B:50% E:50% B:12.5% E:87.5% E:100% 實 施 例5 〇 11.0 11.5 10.2 7.2 〇 E:100% B:25% E:75% B:12.5% E:87.5% E:100% 實 施 例6 〇 10.5 11.2 9.8 7.5 〇 E:100% B:25% E:75% E:100% E:100% 比 較 例2 〇 11.8 10.5 9.9 6.6 〇 E:100% E:100% E:100% E:100% [表5] 孔隙觀察 濕潤向上率(％) 判定 判定 結果 實施例1 〇 〇 63 實施例2 〇 〇 58 實施例3 〇 〇 58 實施例4 〇 〇 58 實施例5 〇 〇 59 實施例6 〇 〇 68 比較例2 〇 〇 59-12- 200927357 [Table 2] Room slip (ML strength Pa) Room temperature elongation (%) High temperature strength (MPa) High temperature elongation (%) Melting point (. 〇 Judgment result judgment result judgment result judgment result judgment solid phase Line liquidus Example 1 〇34.4 〇65 〇20.4 〇53 〇216 223 Example 2 〇39.2 〇61 〇19.2 〇74 〇215 222 Example 3 〇42.3 〇57 〇19.6 〇76 〇216 222 Example 4 〇 37.8 〇68 〇18.1 〇67 〇216 222 Example 5 〇38.7 〇63 〇17.7 〇62 〇216 224 Example 6 〇33.8 〇52 〇17.2 〇59 〇216 226 Example 7 〇33.6 〇53 〇16.8 〇54 〇 217 227 Example 8 〇35.8 〇63 〇17.9 〇55 〇215 226 Example 9 〇40.6 〇60 〇20.3 〇50 〇226 227 Example 10 〇34.4 〇64 〇17.2 〇115 〇229 230 Example 11 〇30.4 〇 68 〇15.2 〇57 〇230 231 Comparative Example 1 〇47.8 X 49 〇22.0 X 46 〇215 218 Comparative Example 2 〇39.4 〇56 〇18.3 〇61 〇217 220 Comparative Example 3 X 18.4 〇77 X 9.2 〇65 〇217 226 Comparative Example 4 X 25.3 75 X 6.1 〇60 〇217 226 Comparative Example 5 〇43.6 〇50 〇21.8 〇52 〇220 222 Comparative Example 6 - - - - - - - - X 217 287 Comparative Example 7 X 27.1 〇68 X 13.5 〇59 〇229 230 Comparative Example 8 X 15.2 〇96 X 4.2 〇88 X 232' [Table 3] High setting time 200h 500h 1000h High temperature (M intensity Pa) High temperature elongation (%) High temperature (M intensity Pa) High temperature elongation (% High temperature (M intensity Pa) High temperature elongation (%) Judgment result judgment result Judgment result Judgment result Judgment result Judgment result Example 1 〇15.4 〇55 〇14.3 〇63 〇13.7 〇73 Example 2 〇18.0 〇61 〇17.9 〇70 〇16.7 〇67 Example 3 〇19.0 〇64 〇19.1 〇66 〇18.4 〇61 Example 4 〇17.5 〇67 〇17.1 〇62 〇17.0 〇72 Example 5 〇16.5 〇60 〇17.8 〇68 〇18.4 〇 65 Example 6 〇15.0 〇56 〇16.3 〇66 〇15.0 〇59 Comparative Example 2 〇17.2 〇55 〇15.4 〇60 〇12.8 〇70 -13- 200927357 [Table 4] Pulling strength (N) Damage morphology Determination of high temperature placement High time and low time to determine Oh 200 h 500h 1000h Judgment of Oh 200h 500h lOOOh Results Results Results Results Results Example 1 〇11.8 11.2 10.3 7.0 〇D: 12.5% E: 87.5% E:100% E:100% E:100% Example 2 〇12.9 11.5 9.9 7.9 〇B: 100% B: 87.5% E: 12.5% B: 50% E: 50% E: 100% Example 3 〇 12.1 11.8 11.2 8.1 〇D: 12.5% E: 87.5% E: 100% E : 100% E: 100% Example 4 〇 11.1 11.1 11.0 8.5 〇 B: 50% E: 50% B: 50% E: 50% B: 12.5% E: 87.5% E: 100% Example 5 〇 11.0 11.5 10.2 7.2 〇E: 100% B: 25% E: 75% B: 12.5% E: 87.5% E: 100% Example 6 〇 10.5 11.2 9.8 7.5 〇 E: 100% B: 25% E: 75% E: 100% E: 100% Comparative Example 2 〇11.8 10.5 9.9 6.6 〇E: 100% E: 100% E: 100% E: 100% [Table 5] Pore observation wet up rate (%) Judgment determination result Example 1 〇 〇63 Example 2 〇〇58 Example 3 〇〇58 Example 4 〇〇58 Example 5 〇〇59 Example 6 〇〇68 Comparative Example 2 〇〇59
<焊料鑄造> 將焊料鑄造用的鑄鐵製釜以氣體燃燒器加熱，使Sn熔 •14- 200927357 解。在已熔解之Sn，根據表1所示之組成依照Ag、Cu、Zn 的順序添加合金元素。添加後在一定時間內攪拌，用内徑 3 0mm、高度110mm之鑄鐵製鑄模進行水冷鑄造，來製造各 組成之焊料合金。依據Sn、Ag、Cu、Zn之組成做成實施例 1〜Π與比較例1〜8之樣品。加入之組成示於表1。 <組成分析> 用鑽子削切焊料，秤量細切之焊料，以酸使其分解。 0 焊料完全分解後移至量瓶內，以水稀釋至標線作爲分析用 試料。所製得之分析用試料係使用感應偶合電漿分析（ICP) 進行Cu、Zn及Ag之組成分析。惟，僅在Ag之組成超過 0.5 %的情形，Ag的含量係藉由硫氰酸鉀滴定法（根據JIS Z 39 10)予以測定。首先將分析用試料以硝酸分解而除去氧化 氮後，加入硫酸鐵（ΙΠ)銨當作指示藥劑。之後以0.03mol/L 硫氰酸鉀標準溶液進行滴定，把溶液呈現微紅褐色的時點 當作終點。從分析用試料之秤取量與在滴定所使用之硫氰 φ 酸鉀標準溶液量算出Ag的含量。組成分析結果示於表1。 <展開率測定> 展開率係依據ns Z 3198-3來測定。針對由鑄鐵製釜 所鑄造而成之表1的全部樣品的焊料，進行壓延成厚度 1.2mm後，衝壓成φ8ιηπι的小片狀，放置在以酒精洗淨後之 3 0x3 0x0.3mm的Cu板上，進一步使液態熔劑滴下1滴以做 成試驗片。其中，小片係由以電子天秤所測定之質量與藉 由阿基米德法所測定之比重，預先算出體積。將試驗片漂 浮在設定爲270°C之金屬熔化浴（solder bath)中加熱20秒， -15- 200927357 而使試驗片的焊料熔融後，邊保持水平邊拉上來’予以冷 却。從預先測定之體積與利用測微計所測定之凝固後試驗 片的焊料高度而算出展開率。通常若展開率低於70%時， 在實際塗抹焊料作業時，大多會感到濕潤性的不良。因此 展開率在70%以上爲合格（在表1的〇）、小於70%的情形爲 不合格（在表1的X)。 外觀： 在外觀試驗，係藉由相同操作者的目視來判定在展開 率測定試驗後殘留在銅板上之焊料的表面光澤。在塗抹焊 料的品質檢査方面，表面光澤係判斷基準之一’由於在焊 料表面產生「縐折」或「縮孔（shrinkage cavity)」而喪失表 面光澤者爲不佳。因此’將焊料表面之狀態分類爲下述3 種。 (1) 合格且特別良好（在表1的〇）：沒有因凝固收縮所致之 大的縮孔、具有金屬光澤、在品質檢査之判定爲容易。 (2) 合格（在表1的△)··沒有因凝固收縮所致之大的縮孔。 金屬光澤雖少，但在品質檢査之判定爲可能。 (3) 不合格（在表1的X):有因凝固收縮所致之大的縮孔’在 品質檢査之判定爲不可能。 <在高溫與室溫之強度及拉伸度> 針對由鑄鐵製釜所鑄造之表1的全部樣品’將除了比 較例6以外的焊料藉由熱壓出成形爲直徑1 2mm棒狀’進 行150〜18CTC數小時之以金饜組織的均質化爲目的之熱處 理後，利用轉盤加工爲平行部直徑係4mm、平行部長度係 -16- 200927357 12 mm之圓棒拉伸試驗片。以保持均熱性之附有3分割爐之 拉伸試驗機、以應變速度爲固定的方式用電腦控制，同時 在試驗溫度125 °C (高溫）及試驗溫度25 °C (室溫）、應變速度 lxl0_3(l/sec)的條件進行拉伸試驗。根據由安裝在拉伸試驗 機的棒狀單位所測定之荷重，算出在試驗片所負荷之應 力，應變量係將在真實應變成爲0.1時的應力作爲強度。 從在拉伸試驗前以測微計預先測定之試驗片長度、與讀取 0 以顯微鏡所測定之破損後的試驗片長度，來算出變形量。 再者，僅在平行部引起變形者，係從所得之變形量算 出拉伸度。又，拉伸試驗係各進行2次，將其平均値當作 強ά與拉伸度的値。在高溫的強度與拉伸度，能夠清楚判 定比既存合金Sn-3.0Ag-0.5Cu更差之數値分別爲強度係 15MPa及拉伸度係50%，在該數値以上者爲合格（在表2之 〇）。在室溫的強度與拉伸度，能夠清楚判定比既存合金 Sn-3.0Ag-0.5Cu更差之數値分別爲強度係30MPa及拉伸度 p 係50%，在該數値以上者爲合格（在表2之〇）。 <熔點> 針對由鑄鐵製釜所鑄造之表1的全部樣品的焊料，將 以鑽子所削切之數g切粉塡裝到鋁製盤內，利用示差熱分 析裝置分析吸熱尖峰與發熱尖峰，而測定固相線溫度及液 相線溫度。液相線溫度係完全熔融時的溫度，在成爲塗抹 焊料的對象之構件的耐熱上爲極重要之要素，在構件的耐 熱上較佳爲小於23(TC。因此，液相線溫度小於230°C爲合 格（在表2的〇）。 -17- 200927357 <高溫放置後在高溫的強度與拉伸度> 針對以與上述<在高溫與室溫之強度及拉伸度>説 相同方法所製作之圓棒拉伸試驗片，利甩恆溫器進行 放置。高溫放置係在125°C經過200小時、500小時、 小時後，分別從恆溫器取出圓棒拉伸試驗片。高溫放 之圓棒拉伸試驗片係以與<在高溫與室溫之強度及拉ί 所説明之相同方法，在試驗溫度125 °C (高溫）、應變速 xlO 3(l/sec)的條件進行拉伸試驗，來測定強度與拉伸 又，拉伸試驗係分別進行2次，將其平均値當作強度 伸度的値。高溫放置後在高溫的強度與拉伸度，能夠 判定比既存合金Sn-3.0Ag-0.5Cu更差之數値分別爲強 12MPa及拉伸度爲50%，在該數値以上者爲合格（在表 〇）。 <髙溫放置後之組織> 針對以與上述在高溫與室溫的強度及拉伸度所説 相同方法所製作之圓棒拉伸試驗片，利用恆溫器進行 放置。高溫放置係在125°C經過200小時、500小時、 小時後，分別進行利用掃瞄電子顯微鏡之組織觀察。 在第1圖顯示比較例2之高溫放置500小時後、在第 顯示實施例3之高溫放置500小時後的組織照片。圖 箭頭爲20//m。參照第1圖，確認在比較例2,於高溫 前沒有觀察到粗大化之第2相粒子。另一方面，參照 圖，確認在實施例3，於高溫放置後亦沒有粗大化之 相粒子。在其他實施例1、2、4、5、6中亦相同。因 明之 高溫 1000 置後 声度> 度1 度。 與拉 清楚 度係 3的 明之 高溫 1000 分別 2圖 中的 放置 第2 第2 此可 -18- 200927357 判定實施例1〜6在高溫環境之組織安定性較比 優異。 <基板封裝> 針對從鑄鐵製釜所鑄造之樣品藉由熱壓! 狀，然後加工成數十//m的粉末，進而與熔劑 焊膏。用所得焊膏將四邊形1C封包封裝於印刷 封裝所用之四邊形1C封包係在1邊以0.5mm 1 根引線，引線的材質係以銅在表面實施鏟錫。 環氧玻璃，接合焊料之焊墊材質爲表面未實施 封裝係在印刷焊膏、搭載四邊形1C封包後，用 料熔融。 <孔隙觀察> 針對以在上述基板封裝所説明之方法予以 板，用透射型X射線檢査裝置觀察在四邊形1C 部分產生之孔隙。孔隙係由於因不濕潤所殘存 劑之分解氣體等原因，而形成數十/zm的孔隙 會因所產生之位置而對可靠性造成影響，尤其 成不良影響的位置爲引線下部。在引線下部 隙，係以X射線檢査裝置進行圖像攝影，並從 存在於引線下部之孔隙數。數比較例1〜6及養 全部的孔隙數爲0(zero)。由於確認在引線下部 因此全部判定爲合格（在表5的〇）。 <濕潤向上率測定> 針對以上述基板封裝所説明之方法予以 較例2更爲 ϋ成形爲棒 混合加工爲 基板上。在 0距具有25 基板材質爲 鍍敷的銅。 反射爐使焊 封裝後之基 封包的引線 的氣泡、熔 。已知孔隙 對可靠性造 是否存在孔 該圖像數出 f施例2時， 沒有孔隙， 封裝後的基 -19- 200927357 板，以150倍之實體顯微鏡觀察、攝影引線前端剖面，藉 由覆有焊料之部分相對於銅引線前端剖面之比率，來決定 濕潤向上率。具體而言，引線前端剖面照片中，看到茶色 之部分判斷爲銅引線，看到銀色之部分判斷爲焊料部分， 從焊料部分之面積率來測定。濕潤向上率，能夠清楚判定 比既存合金Sn-3.0Ag-0.5Cu更差之數値爲55%，在該數値 以上者爲合格（在表5的〇）。結果示於表5。 _ <拉拔強度（pull strength)測定〉 〇 以上述 <基板封裝>所説明之方法予以封裝後之基板係 用恆溫器進行髙溫放置。高溫放置係在1 25 °C經過200小 時、500小時、1000小時後，分別將基板從恆溫器取出。 用高溫放置前（放置時間0小時）及高溫放置後之基板，依 照JIS Z 3198-6之無鉛焊料試驗方法進行焊料接合部45度 拉拔試驗，測定拉拔強度。拉拔強度係將四邊形1C封包的 引線部分，以前端加工成勾子形狀的金屬棒往相對於基板 g 爲45度之方向進行拉伸，到破損爲止的最大荷重爲拉拔強 度。拉拔試驗係以拉拔速度10mm/min、在各基板實施8根， 將8根的平均値作爲拉拔強度。拉拔強度，能夠清楚判定 比既存合金Sn-3.0Ag-0.5Cu更差之數値爲6N(牛頓），在該 數値以上者爲合格（在表4的〇）。 <破損形態測定> 評價以上述拉拔強度測定所説明之方法進行拉伸試驗 後的破損形態。破損形態方面，引線本身破損之形態爲A。 引線與焊料的界面破損之形態爲B。焊料本身破損之形態 -20- 200927357 爲C。焊料與焊墊之界面破損的形態爲D。焊墊與環氧玻 璃基板的界面破損之形態爲E。在破損形態測定中，在接 合部分中最具耐久性爲沒有部分破損。破損形態爲A時， 可知引線部分之耐久性比藉由焊料接合所形成之接合部更 低。同樣地，破損形態爲B時，於塗抹焊料時所形成之構 件與焊料界面；C時爲焊料合金；D時爲在塗抹焊料時所 形成之焊料與焊墊界面；E時爲焊墊與基板之接著力係各 自爲最不具耐久性者。因此，破損形態爲C以外時，可判 斷存在於接合部之焊料合金係具有耐久性，因此破損形態 C以外者爲合格（在表4的〇）。 <封裝後之組織觀察> ' 以上述基板封裝所説明之方法予以封裝後之基板係用 恆溫器進行高溫放置，針對實施例1〜6與比較例2中封裝 後的印刷基板與構件之引線界面，進行掃瞄電子顯微鏡之 組織觀察。在封裝後緊接著組織觀察，觀察在引線-焊料問 及焊料-焊墊間之認爲在塗抹焊料時所形成的金屬間化合 物層》在任一合金中，金屬間化合物層的厚度均爲l〇em 以下，因此可確認塗抹焊料係良好地結束。又，針對在125 °C經過200小時、500小時、1000小時後之印刷基板亦同 樣地進行組織觀察，可知實施例1〜6之金屬間化合物層的 成長較比較例2更少。 在第3圖及第4圖係例示實施例3的焊料時之金屬間 化合物層的成長。第3圖係塗抹焊料即後之引線與焊料間 的剖面之掃瞄電子顯微鏡照片，第4圖爲1 000小時後之剖 -21- 200927357 面照片。照片的箭頭爲10/zm。符號10爲引線部分，符號 12爲焊料部分。存在於引線部10與焊料部12之間的是金 屬間化合物層（符號14)。照片中可見到引線1〇與焊料12 中間的色調。關於金屬間化合物層，若比較第3圖與第4 圖來看，幾乎沒有變化。 若參照實施例1〜實施例11，以外觀、展開率、熔點、 室溫強度、室溫拉伸度、高溫強度、高溫拉伸度、高溫放 0 置後之高溫強度、高溫放置後之高溫拉伸度、拉拔強度、 高溫放置後之拉拔強度、拉拔試驗時之破損形態測定、孔 隙觀察、濕潤向上率等評價項目，能夠通過上述判定基準。 其間Ag、Cu、Zn之組成範圍，Ag爲0.01質量％〜1.〇質量 %、（：11爲0.01質量％〜1_0質量％、211爲0.1質量％〜1.〇質 量％。其係本發明的焊料之組成範圍，顯示本發明之無鉛焊 料係具有良好的特性。 比較例7係在含有3.0質量％的Ag之Sn-Ag-Cu的標準 φ 組成中，含〇·4質量％Zn的情形。此時拉伸度的評價項目 爲X的評價。因此，可知由於僅在Sn-Ag-Cu加入Zn，因而 完全破壞了平衡。 比較例3係由Sn-Ag-Cu之標準組成，使Ag的量減少 爲1.0質量％的情形，認爲具有抑制Ag3Sn粒子之粗大化的 效果。但是，室溫強度與高溫強度卻降低。 比較例6係在將Ag的比率進一步減少爲〇.〇1質量％的 情形，使Cu比Sn-Ag-Cu之標準比率（0.5質量％)大（2.0質 量％)的情形。雖然含有0.01質量％之Zn，但液相熔點卻變 -22- 200927357 高。 比較例5係從Sn-Ag-Cu之標準組成’使Ag的含量減 少爲0.3質量％，用Zn以補償在使Ag減少時產生之室溫強 度與高溫強度的降低（參照比較例2)的意圖之組成。但是’ 由於Zn比1.5質量％多，因此展開率反而降低。比較例5 雖然在本發明之規定範圍內含有Ag及Cu，但爲Zn多的情 形。由此可知，即使添加Zn當作使Ag減少之補償，超過 巍 1.0質量％的範圍則係過多。 Ό 比較例4係顯示由Sn-Ag-Cu之標準組成使Ag的含量 減少爲0.3質量％，Cu的含量增加爲0.7質量％的情形。基 本上由於使Ag降低，因此與比較例3相同，室溫強度與高 溫強度降低。. 比較例7係使Ag的含量進一步降低爲0.005質量％， Cu與Zn各含有〇.1質量％者。此時，高溫強度降低，同時 外觀亦變得不良。由此，如實施例1〜6所示之範圍，Ag 0 係至少必須爲0.0 1質量％以上。 比較例8係完全不含Ag、Cu、Zn、僅有Sn的情形。 此時，外觀、展開率、高溫強度、熔點等許多方面均不能 供於實用。 如上所述，本發明爲具有Sn-Ag-Cu-Zn的4元系之組 成’其係由0.01〜1.0質量％之Ag、〇.〇1〜1.0質量％之Cu、 0.1〜1.0質量％之Zn、剩餘部分爲Sfi所構成的無鉛焊料， 與Sn-Ag-Cu系的焊料比較，而Ag的比率變少，不易引起 熱疲勞。一方面，藉由含有預定量之Zn，能夠確保高溫強 -23- 200927357 度、拉伸度不降低。 【產業上之可利用性】 本發明係可利用於無鉛焊料。 【圖式簡單說明】 第1圖在比較例2「高溫放置500小時後」之條件的 情況之組織照片。 第2圖在實施例3「高溫放置500小時後」之條件的 情況之組織照片。 第3圖在實施例3「無高溫放置」之條件的引線-焊料 界面之剖面照片。 第4圖在實施例3「1 000小時後」之條件的引線-焊料 界面之剖面照片。 【主要元件符號說明】 10 引線部 12 焊料部 14 金屬間化合物層 -24-<Solder Casting> A cast iron kettle for solder casting was heated by a gas burner to dissolve Sn. In the melted Sn, an alloying element is added in the order of Ag, Cu, and Zn according to the composition shown in Table 1. After the addition, the mixture was stirred for a predetermined period of time, and water-cooled casting was carried out using a cast iron mold having an inner diameter of 30 mm and a height of 110 mm to produce a solder alloy of each composition. Samples of Examples 1 to Π and Comparative Examples 1 to 8 were prepared in accordance with the compositions of Sn, Ag, Cu, and Zn. The composition of the addition is shown in Table 1. <Composition analysis> The solder was cut with a drill, and the finely-cut solder was weighed and decomposed with an acid. 0 After the solder is completely decomposed, it is transferred to a measuring flask and diluted with water to the marking line for analysis. The analytical samples prepared were analyzed by compositional analysis of Cu, Zn and Ag using inductively coupled plasma analysis (ICP). However, in the case where the composition of Ag exceeds 0.5%, the content of Ag is measured by potassium thiocyanate titration (according to JIS Z 39 10). First, the analytical sample was decomposed with nitric acid to remove nitrogen oxide, and then ammonium ferric sulfate was added as an indicator. Thereafter, titration was carried out with a 0.03 mol/L potassium thiocyanate standard solution, and the time at which the solution appeared reddish brown was regarded as the end point. The content of Ag was calculated from the amount of the analytical sample and the amount of the standard solution of thiocyanate potassium citrate used in the titration. The results of the composition analysis are shown in Table 1. <Expansion rate measurement> The expansion ratio was measured in accordance with ns Z 3198-3. The solder of all the samples of Table 1 cast from a cast iron kettle was rolled to a thickness of 1.2 mm, and then pressed into a small piece of φ8 ηηπι, and placed in a Cu plate of 3 0×3 0×0.3 mm after being washed with alcohol. Further, one drop of the liquid flux was further dropped to prepare a test piece. Among them, the small piece is calculated in advance from the mass measured by the electronic balance and the specific gravity measured by the Archimedes method. The test piece was floated in a metal melting bath set at 270 ° C for 20 seconds, -15 - 200927357, and the solder of the test piece was melted, and then pulled while being horizontally pulled to be cooled. The development ratio was calculated from the volume measured in advance and the height of the solder of the test piece after solidification measured by a micrometer. In general, when the expansion ratio is less than 70%, the wettability is often felt when the solder is actually applied. Therefore, the development rate of 70% or more is acceptable (in Table 1), and less than 70% is unacceptable (in Table 1 X). Appearance: In the appearance test, the surface gloss of the solder remaining on the copper plate after the development rate measurement test was judged by the same operator's visual observation. In terms of the quality inspection of the applied solder, one of the criteria for determining the surface gloss is that the surface gloss is lost due to the occurrence of "folding" or "shrinkage cavity" on the surface of the solder. Therefore, the state of the solder surface is classified into the following three types. (1) Qualified and particularly good (in Table 1): There is no large shrinkage due to solidification shrinkage, metallic luster, and it is easy to judge quality inspection. (2) Qualified (in Table △) · There is no large shrinkage hole due to solidification shrinkage. Although the metallic luster is small, it is possible to judge the quality inspection. (3) Failure (in Table X): There is a large shrinkage hole due to solidification shrinkage, which is impossible to judge by quality inspection. <Strength and elongation at high temperature and room temperature> For all samples of Table 1 cast from a cast iron kettle, the solder other than Comparative Example 6 was formed by hot extrusion into a rod shape of 1 2 mm in diameter. After heat treatment for the purpose of homogenization of the metal lanthanum structure for a period of 150 to 18 CTC for several hours, a round bar tensile test piece having a parallel portion diameter of 4 mm and a parallel portion length of -16 to 200927357 12 mm was processed by a turntable. It is controlled by computer with a tensile tester with a 3-segment furnace to maintain the soaking temperature. The test temperature is 125 °C (high temperature) and the test temperature is 25 °C (room temperature), strain rate. The tensile test was carried out under the conditions of lxl0_3 (l/sec). The stress applied to the test piece was calculated from the load measured by the rod-shaped unit attached to the tensile tester, and the strain was the intensity at which the true strain became 0.1 as the strength. The amount of deformation was calculated from the length of the test piece measured in advance by the micrometer before the tensile test and the length of the test piece after the damage was measured by the microscope. Further, if the deformation is caused only in the parallel portion, the degree of stretch is calculated from the amount of deformation obtained. Further, the tensile test was carried out twice each, and the average enthalpy was regarded as the enthalpy of stretching and stretching. At the high temperature strength and the degree of elongation, it can be clearly determined that the number 更 which is worse than the existing alloy Sn-3.0Ag-0.5Cu is 15 MPa in strength and 50% in tensile strength, respectively. Table 2). The strength and the degree of elongation at room temperature can be clearly determined to be worse than the existing alloy Sn-3.0Ag-0.5Cu. The strength is 30 MPa and the elongation p is 50%, respectively. (between Table 2). <Melting point> For the solder of all the samples of Table 1 cast from a cast iron kettle, the number of cut chips cut by the drill was placed in an aluminum pan, and the endothermic peak was analyzed by a differential thermal analyzer. The heat peak was measured and the solidus temperature and liquidus temperature were measured. The temperature at which the liquidus temperature is completely melted is an extremely important factor in the heat resistance of the member to be coated with solder, and is preferably less than 23 (TC) in heat resistance of the member. Therefore, the liquidus temperature is less than 230°. C is acceptable (〇 in Table 2). -17- 200927357 <Strength and elongation at high temperature after high temperature placement> For the above <Strength and stretch at high temperature and room temperature> The round bar tensile test piece prepared by the same method was placed in a thermostat, and the high temperature was placed at 125 ° C for 200 hours, 500 hours, and then the round bar tensile test piece was taken out from the thermostat. The round bar tensile test piece is subjected to the same conditions as described in "High-temperature and room-temperature strength and pull-up" at a test temperature of 125 ° C (high temperature) and a variable speed of xlO 3 (l/sec). The tensile test is used to measure the strength and the tensile strength. The tensile test is carried out twice, and the average enthalpy is used as the strength elongation. After the high temperature is placed, the strength and the elongation at high temperature can be determined as compared with the existing alloy. The worse number of Sn-3.0Ag-0.5Cu is 12MPa and The elongation is 50%, and those above the number are acceptable (in the table). <Structure after the temperature is placed> It is produced in the same manner as the above-mentioned strength and elongation at high temperature and room temperature. The round bar tensile test piece was placed by a thermostat, and the high temperature was placed at 125 ° C for 200 hours, 500 hours, and hours, and then observed by a scanning electron microscope. Fig. 1 shows Comparative Example 2 The photograph of the structure after standing at a high temperature for 500 hours and after standing at the high temperature of the display example 3 for 500 hours, the arrow is 20/m. Referring to Fig. 1, it was confirmed that in Comparative Example 2, no coarsening was observed before the high temperature. On the other hand, referring to the figure, it was confirmed that the phase particles were not coarsened after being placed at a high temperature in Example 3. The same applies to the other examples 1, 2, 4, 5, and 6. High temperature 1000 after setting sound degree > degree 1 degree. With the brightness of the system 3, the high temperature of 1000 is respectively 2 placed in the figure 2nd second can be -18- 200927357 It is determined that the stability of the embodiment 1 to 6 in a high temperature environment Excellent in comparison. <Substrate packaging ≫ The sample cast from the cast iron kettle is hot-pressed, then processed into tens of / / m powder, and then with the flux solder paste. The resulting solder paste is used to encapsulate the quadrilateral 1C package in the quadrilateral used in the printing package. The 1C package is made of 0.5mm and 1 lead on one side, and the material of the lead is made of copper on the surface. The epoxy glass is soldered to the surface of the solder. The surface is not packaged in the printed solder paste, and the quadrilateral 1C package is mounted. Thereafter, the material was melted. <Pore observation> The pores generated in the square 1C portion were observed by a transmission type X-ray inspection apparatus in accordance with the method described in the above substrate package. The pores are formed by the decomposition gas of the residual agent which is not wetted, and the formation of tens/zm pores affects the reliability due to the position generated, and particularly the position of the lead is the lower portion of the lead. In the lower gap of the lead, an image is taken by an X-ray inspection apparatus and the number of pores existing in the lower portion of the lead. The number of pores of Comparative Examples 1 to 6 and the total number of the cells was 0 (zero). Since it was confirmed at the lower portion of the lead wire, it was all judged as pass (in Table 5). <Measurement of Wetting Up Rate> For the method described in the above substrate package, Comparative Example 2 was further formed into a rod and mixed into a substrate. At a distance of 0, there are 25 substrates made of plated copper. The reverberatory furnace causes the bubbles of the lead of the base package after soldering to be melted. It is known that there is a hole in the reliability of the hole. When the image is counted as Example 2, there is no void, and the packaged base-19-200927357 plate is observed by a solid microscope at 150 times, and the front end section of the photographing lead is covered. The ratio of the solder portion to the front end profile of the copper lead determines the wet up rate. Specifically, in the cross-sectional photograph of the front end of the lead, the portion in which the brown color was observed was judged to be a copper lead, and the portion in which the silver was observed was judged to be a solder portion, and was measured from the area ratio of the solder portion. The wet up rate can clearly determine that the number 値 which is worse than the existing alloy Sn-3.0Ag-0.5Cu is 55%, and those above the number 値 are acceptable (in Table 5). The results are shown in Table 5. _ <Pull strength measurement> 基板 The substrate packaged by the method described in the above <Substrate Package> was placed in a thermostat using a thermostat. The high temperature was placed at 125 ° C for 200 hours, 500 hours, and 1000 hours, and the substrate was taken out from the thermostat. The substrate was subjected to a 45-degree pull-out test of the solder joint portion in accordance with the lead-free solder test method of JIS Z 3198-6 before the high-temperature standing (position time of 0 hours) and the substrate after the high temperature was placed, and the drawing strength was measured. The drawing strength is such that the lead portion of the rectangular 1C package is stretched in a direction of 45 degrees with respect to the substrate g by a metal bar having a hook shape at the front end, and the maximum load until breakage is the drawing strength. The drawing test was performed on each of the substrates at a drawing speed of 10 mm/min, and the average enthalpy of the eight pieces was taken as the drawing strength. The drawing strength can clearly determine that the number 値 which is worse than the existing alloy Sn-3.0Ag-0.5Cu is 6N (Newton), and those above the number of 値 are acceptable (in Table 4). <Measurement of damage form> The damage pattern after the tensile test was carried out by the method described in the above-described drawing strength measurement. In terms of the damage form, the shape of the lead itself is broken. The interface between the lead and the solder is broken in the form of B. The shape of the solder itself is broken -20- 200927357 is C. The interface between the solder and the pad is broken in the form of D. The interface between the pad and the epoxy glass substrate is broken in the form of E. In the damage morphology measurement, the most durable in the joint portion was not partially broken. When the damage pattern is A, it is understood that the durability of the lead portion is lower than that of the joint portion formed by solder bonding. Similarly, when the damage form is B, the interface formed between the solder and the solder is formed; when C is a solder alloy; D is the interface between the solder and the pad formed when the solder is applied; and when E is the pad and the substrate The force is then the least durable. Therefore, when the damage pattern is other than C, it is judged that the solder alloy existing in the joint portion has durability, and therefore, the damage pattern C is acceptable (see Table 4). <Structure observation after encapsulation> 'The substrate packaged by the method described in the above substrate package was placed at a high temperature with a thermostat, and the printed circuit boards and members after the packages of Examples 1 to 6 and Comparative Example 2 were placed. The lead interface was observed by a scanning electron microscope. Immediately after the encapsulation, the structure is observed, and the intermetallic compound layer formed between the solder and the solder pad is considered to be formed when the solder is applied. In any alloy, the thickness of the intermetallic compound layer is l〇. Since em is the following, it can be confirmed that the application solder is well finished. Further, the structure of the printed circuit board after 200 hours, 500 hours, and 1000 hours at 125 °C was observed in the same manner, and it was found that the growth of the intermetallic compound layers of Examples 1 to 6 was less than that of Comparative Example 2. The growth of the intermetallic compound layer in the case of the solder of Example 3 is shown in Figs. 3 and 4 . Fig. 3 is a scanning electron micrograph of a cross section between a lead and a solder after soldering, and Fig. 4 is a cross-sectional view taken after 1 000 hours - 21 - 200927357. The arrow for the photo is 10/zm. Symbol 10 is a lead portion, and symbol 12 is a solder portion. Present between the lead portion 10 and the solder portion 12 is an intermetallic compound layer (symbol 14). The hue between the lead 1 turns and the solder 12 can be seen in the photo. Regarding the intermetallic compound layer, when comparing FIGS. 3 and 4, there is almost no change. Referring to Examples 1 to 11, the appearance, development ratio, melting point, room temperature strength, room temperature tensile strength, high temperature strength, high temperature tensile strength, high temperature strength after high temperature release, and high temperature after high temperature placement The evaluation criteria such as the degree of stretching, the drawing strength, the drawing strength after standing at a high temperature, the measurement of the damage form during the drawing test, the observation of the pores, and the rate of wetting up can be passed. In the composition range of Ag, Cu, and Zn, Ag is 0.01% by mass to 1. 〇% by mass, (: 11 is 0.01% by mass to 1% by mass, and 211 is 0.1% by mass to 1. 〇% by mass). The composition range of the solder shows that the lead-free solder of the present invention has good characteristics. Comparative Example 7 is a case where Zn·4% by mass of Zn is contained in the standard φ composition of Sn-Ag-Cu containing 3.0% by mass of Ag. The evaluation item of the degree of stretching at this time was the evaluation of X. Therefore, it was found that the balance was completely broken by adding Zn only to Sn-Ag-Cu. Comparative Example 3 was composed of a standard of Sn-Ag-Cu, and Ag was made. When the amount is reduced to 1.0% by mass, it is considered to have an effect of suppressing coarsening of Ag3Sn particles. However, room temperature strength and high temperature strength are lowered. Comparative Example 6 is to further reduce the ratio of Ag to 〇.〇1 mass. In the case of %, the ratio of Cu to the standard ratio (0.5 mass%) of Sn-Ag-Cu is large (2.0% by mass). Although 0.01% by mass of Zn is contained, the liquidus melting point becomes -22-200927357. Example 5 is based on the standard composition of Sn-Ag-Cu' to reduce the content of Ag to 0.3% by mass, using Zn The composition of the intention of reducing the room temperature strength and the high temperature strength (refer to Comparative Example 2) when Ag is decreased is compensated for. However, since the Zn ratio is more than 1.5% by mass, the development ratio is rather lowered. Comparative Example 5 Although the present invention is In the case where Ag and Cu are contained in the predetermined range, the amount of Zn is large. Therefore, even if Zn is added as compensation for reducing Ag, the range exceeding 巍1.0% by mass is excessive. Ό Comparative Example 4 shows that Sn is obtained by Sn. The standard composition of Ag-Cu is such that the content of Ag is reduced to 0.3% by mass and the content of Cu is increased to 0.7% by mass. Basically, since Ag is lowered, the room temperature strength and the high-temperature strength are lowered as in Comparative Example 3. In Comparative Example 7, the content of Ag was further reduced to 0.005% by mass, and each of Cu and Zn contained 0.1% by mass. At this time, the high-temperature strength was lowered and the appearance was also poor. Thus, as in Example 1 In the range indicated by 6, the Ag 0 must be at least 0.01% by mass or more. Comparative Example 8 is completely free of Ag, Cu, Zn, and only Sn. In this case, appearance, development ratio, high temperature strength, melting point, and the like. Many aspects are not available for practical use As described above, the present invention is a composition of a quaternary system having Sn-Ag-Cu-Zn, which is 0.01 to 1.0% by mass of Ag, 〇.〇1 to 1.0% by mass of Cu, 0.1 to 1.0% by mass. The Zn and the remaining portion are lead-free solders composed of Sfi, and the ratio of Ag is smaller than that of Sn-Ag-Cu solder, which is less likely to cause thermal fatigue. On the other hand, high temperature can be ensured by containing a predetermined amount of Zn. Strong -23- 200927357 degrees, the degree of stretch does not decrease. [Industrial Applicability] The present invention can be utilized for lead-free solder. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a photograph of a structure in the case of the condition of "After 500 hours at a high temperature" in Comparative Example 2. Fig. 2 is a photograph of the organization in the case of the condition of "after 500 hours at a high temperature" in Example 3. Fig. 3 is a cross-sectional photograph of the lead-solder interface under the condition of "no high temperature placement" in the third embodiment. Fig. 4 is a cross-sectional photograph of the lead-solder interface of the condition of "after 1 000 hours" in Example 3. [Main component symbol description] 10 Lead portion 12 Solder portion 14 Intermetallic compound layer -24-