JP7291320B2 - Method for manufacturing solder joints - Google Patents
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本発明は、はんだ接合部の製造方法に関し、特に錫銅系はんだ合金を用いたはんだ接合部の製造方法に関するものである。 TECHNICAL FIELD The present invention relates to a method for manufacturing a solder joint, and more particularly to a method for manufacturing a solder joint using a tin-copper-based solder alloy.
環境上から、ミクロ電子部品の組み立てに用いる大半のはんだ合金は鉛の含有を減少した組成に変わっている。そして、現在では多くのはんだ合金は、Ｓｎ－Ａｇ－Ｃｕや、Ｓｎ－Ｃｕ－Ｎｉ合金を主成分としている。はんだ界面の接合部では、作業中、及び冷却中にＣｕ６Ｓｎ５金属間化合物（以下、単に「Ｃｕ６Ｓｎ５金属間化合物」又は「Ｃｕ６Ｓｎ５」と標記する場合がある。）が形成され、マイクロ電子回路のはんだ信頼性に大きく影響を及ぼす、はんだと界面の間の連続相を形成することになる。したがって、Ｃｕ６Ｓｎ５の結晶構造を安定した状態に維持することは、電子部品の信頼できる製造とサービスに適用するうえで重要である。電子製品のライフサイクルの間で変化する可能性がある様々な結晶構造中に存在するＣｕ６Ｓｎ５金属間化合物を考えた場合、特にこの金属間化合物の安定化は重要な課題である。 For environmental reasons, most solder alloys used in the assembly of microelectronic components have been modified to contain less lead. At present, many solder alloys are mainly composed of Sn--Ag--Cu and Sn--Cu--Ni alloys. Intermetallic Cu6Sn5 ( hereinafter sometimes simply referred to as "Cu6Sn5 intermetallic compound" or "Cu6Sn5") is formed at the joints of the solder interface during operation and cooling, and is used for microelectronic circuits. A continuous phase is formed between the solder and the interface, which greatly affects the solder reliability of the solder. Therefore, maintaining the crystal structure of Cu6Sn5 in a stable state is important for reliable manufacturing and service applications of electronic components. Stabilization of this intermetallic compound is particularly important when considering the Cu6Sn5 intermetallic compound present in various crystal structures that may change during the life cycle of electronic products.
このＣｕ６Ｓｎ５金属間化合物は、１８６℃以下で六方晶から斜方晶の結晶構造に固相変態する。錫銅系の合金を用いてはんだ接合部を形成する場合、通常２３０℃より高い温度まで昇温した後冷却して凝固させる。冷却の際に六方晶のＣｕ６Ｓｎ５金属間化合物が形成され、電子部品に残存すると、その作動時に固相変態が起こる可能性がある。そして、この変態に伴って体積変化等が発生すると金属間化合物そのものに亀裂が発生することで、接合部の強度が低下したり、電気抵抗が増加したりする場合がある。また、はんだリフロー工程を複数回繰り返すと、その度に結晶構造が変化することとなるため、その繰り返しによりＣｕ６Ｓｎ５金属間化合物に亀裂が発生する可能性が生じる。そこで、本発明者は、溶融状態から凝固までのプロセスにおいて冷却温度を制御することによって、凝固した接合部に生成するＣｕ６Ｓｎ５金属間化合物を、それに伴う体積変化が最小限になる温度領域で積極的に安定した状態の斜方晶に変態させ、作動時あるいは製造時に相変態に伴う体積変化、及び体積変化に起因した歪や亀裂の発生などを抑制する方法を提案している（特許文献１）。 This Cu6Sn5 intermetallic compound undergoes a solid-phase transformation from a hexagonal crystal structure to an orthorhombic crystal structure at 186° C. or lower. When solder joints are formed using tin-copper based alloys, they are usually heated to a temperature higher than 230° C. and then cooled to solidify. If a hexagonal Cu6Sn5 intermetallic compound is formed during cooling and remains in the electronic component, a solid phase transformation can occur during its operation. If a volume change or the like occurs with this transformation, the intermetallic compound itself cracks, which may reduce the strength of the joint and increase the electrical resistance. In addition, when the solder reflow process is repeated multiple times, the crystal structure changes each time, and the repetition may cause cracks in the Cu6Sn5 intermetallic compound. Therefore, the present inventors actively controlled the Cu6Sn5 intermetallic compound formed in the solidified joint in a temperature range in which the accompanying volume change is minimized by controlling the cooling temperature in the process from the molten state to the solidification. We have proposed a method of transforming to a stable orthorhombic crystal to suppress the volume change accompanying the phase transformation during operation or manufacturing, and the generation of strain and cracks due to the volume change (Patent Document 1). .
特許文献１に記載のように、本発明者は、１８６℃以上で溶融するＳｎ－Ｃｕ二元合金、あるいはこれに対して他の元素を含むがＣｕ６Ｓｎ５金属間化合物を生成する合金では、冷却温度履歴によっては、Ｃｕ６Ｓｎ５金属間化合物の全てが六方晶から斜方晶に変態する場合と、六方晶のうちの一部だけが斜方晶に変態し、六方晶と斜方晶が混在する場合があることを知見した。そして、冷却温度と冷却時間との関係から、冷却履歴とＣｕ６Ｓｎ５金属間化合物の結晶構造の関係を実験により導出した（図１参照）。図１に示すように、Ｘ軸に時間（秒）、Ｙ軸に温度（℃）で示した二次元図において、冷却温度と冷却時間の関係から、（１）１００％安定斜方晶Ｃｕ６Ｓｎ５（η’－Ｃｕ６Ｓｎ５）に変態する領域（斜方晶領域）と、（２）η’－Ｃｕ６Ｓｎ５に変態しない状態の六方晶Ｃｕ６Ｓｎ５（η－Ｃｕ６Ｓｎ５）が混在する領域（斜方晶と六方晶の混合領域）と、（３）比較的短時間で冷却した場合の１００％準安定η－Ｃｕ６Ｓｎ５領域（六方晶領域）が存在し、これらが１８６℃以下の温度において、２つの時間－温度－変態曲線（ＴＴＴ曲線）により区画されることを確認した。そして、図１に基づき、Ｃｕ６Ｓｎ５金属間化合物を安定した状態の斜方晶に変態させる方法として、（ｉ）１４０～１６０℃程度で４０００秒程度保持することによって、斜方晶領域を通過させ、全てのＣｕ６Ｓｎ５金属間化合物を六方晶から斜方晶に変態させる方法、（ii）１２０～１７５℃程度で２００秒程度保持することによって、斜方晶と六方晶の混合領域を通過させ、一部のＣｕ６Ｓｎ５金属間化合物を六方晶から斜方晶に変態させる方法を提案した。
As described in US Pat. No. 5,200,400, the inventors have found that in Sn—Cu binary alloys melting above 186° C., or in alloys containing other elements but forming Cu 6 Sn 5 intermetallics, , depending on the cooling temperature history, there are cases where all the Cu 6 Sn 5 intermetallic compounds transform from hexagonal to orthorhombic crystals, and only a part of the hexagonal crystals transforms into orthorhombic crystals, and hexagonal and orthorhombic It was found that crystals may be mixed. Then, from the relationship between the cooling temperature and the cooling time, the relationship between the cooling history and the crystal structure of the Cu 6 Sn 5 intermetallic compound was derived by experiment (see FIG. 1). As shown in FIG. 1, in a two-dimensional diagram with time (seconds) on the X-axis and temperature (° C.) on the Y-axis, from the relationship between the cooling temperature and the cooling time, (1) 100% stable orthorhombic Cu 6 and (2) hexagonal Cu 6 Sn 5 ( η-Cu 6 Sn ) in a state not transformed to η'-Cu 6 Sn 5 ( orthorhombic region). 5 ) mixed region (orthorhombic and hexagonal mixed region) and (3) 100% metastable η-Cu 6 Sn 5 region (hexagonal region) when cooled in a relatively short time. , which are subdivided by two time-temperature-transformation curves (TTT curves) at temperatures below 186°C. Then, based on FIG. 1, as a method for transforming the Cu 6 Sn 5 intermetallic compound into the orthorhombic crystal in a stable state, (i) the orthorhombic region is transformed by holding at about 140 to 160° C. for about 4000 seconds. (ii) a mixed region of orthorhombic and hexagonal by holding at about 120 to 175 ° C. for about 200 seconds proposed a method to transform some Cu 6 Sn 5 intermetallics from hexagonal to orthorhombic by passing through .
特許文献１に記載の発明では、前記（ｉ）の方法により、全てのＣｕ６Ｓｎ５金属間化合物を斜方晶に変態させることが最善であり、前記（ii）の方法により斜方晶と六方晶との混合状態に変態させることは次善であるという立場であった。これは、作動時のＣｕ６Ｓｎ５金属間化合物の変態をより確実に防止できると考えたためである。
In the invention described in
しかし、（ｉ）の方法では、１４０～１６０℃程度の温度範囲での経過時間（保持時間とも称する。）として４０００秒程度の時間を必要とすることから、はんだ接合部の製造工程の実情に鑑みるとより短時間の冷却工程が求められる。特に、はんだ接合部の製造工程においては、接合が不十分な可能性がある場合は、はんだ合金を溶融、冷却する工程を複数回行うことが多い。そのため、冷却時間が長いことは生産性の低下、製造コストの上昇を招くことになる。 However, the method (i) requires about 4000 seconds as the elapsed time (also referred to as holding time) in the temperature range of about 140 to 160° C. In view of this, a shorter cooling process is required. In particular, in the process of manufacturing a solder joint, when there is a possibility that the joint may be insufficient, the process of melting and cooling the solder alloy is often performed multiple times. Therefore, a long cooling time leads to a decrease in productivity and an increase in manufacturing cost.
また、（ii）の方法に関しては斜方晶と六方晶との混合物であり作動時のＣｕ６Ｓｎ５金属間化合物の変態を避けられず、斜方晶が存在することによる意義は必ずしも十分ではない可能性があると考えられた。そのため、１２０～１７５℃程度の温度範囲での経過時間（保持時間とも称する。）は２００秒程度ではあっても、その効果は必ずしも十分なものとはならないと考えられた。 In addition, regarding the method (ii), it is a mixture of orthorhombic and hexagonal crystals, and transformation of the Cu6Sn5 intermetallic compound during operation cannot be avoided, and the presence of orthorhombic crystals may not necessarily be of sufficient significance. It was thought that there was Therefore, even if the elapsed time (also referred to as holding time) in the temperature range of about 120 to 175° C. is about 200 seconds, the effect is not necessarily sufficient.
そこで、本発明の目的とするところは、はんだ合金の溶融、冷却凝固を複数回行う場合であっても、作動時に相変態に伴う体積変化、及び体積変化に起因した歪や亀裂の発生などを抑制した信頼性の高い接合部を生産性良く形成可能なはんだ接合部の製造方法を提供することにある。 Therefore, the object of the present invention is to prevent the volume change due to phase transformation during operation, and the generation of strain and cracks due to the volume change, even when the solder alloy is melted and cooled and solidified multiple times. It is an object of the present invention to provide a method for manufacturing a solder joint which enables formation of a highly reliable joint with high productivity.
本発明者は、前述の課題解決のために鋭意検討を行った。その結果、意外にも、Ｃｕ６Ｓｎ５金属間化合物の安定斜方晶と六方晶の混在領域を所定の条件で通過させると、はんだ合金の溶融、冷却凝固を複数回行っても、信頼性の高い接合部を生産性良く形成可能であることを見出し、本発明を完成させるに至った。 The inventor of the present invention has made intensive studies to solve the problems described above. As a result, unexpectedly, when the Cu6Sn5 intermetallic compound is passed through a stable mixed region of orthorhombic and hexagonal crystals under predetermined conditions, even if the solder alloy is melted and cooled and solidified multiple times, a highly reliable joint can be obtained. The present inventors have found that the portion can be formed with high productivity, and have completed the present invention.
本発明は、Ｃｕ：０．３～７．６重量％、残部がＳｎ及び不可避不純物である合金を１８６℃以上に昇温した後１８６℃以下に冷却する冷却工程を複数回繰り返し行うはんだ接合部の製造方法であって、各冷却工程において、合金を１８６℃以上に昇温した後、合金の温度の経時変化を示す冷却温度線がＣｕ６Ｓｎ５の１８６℃以上で安定な六方晶と、１８６℃以下で安定な斜方晶の混在領域を通過し、かつ、１６０～１３７℃の温度範囲での保持時間が９６～３０５秒となるように冷却する、はんだ接合部の製造方法に関する。 The present invention is a solder joint in which a cooling process of heating an alloy containing 0.3 to 7.6% by weight of Cu and the balance being Sn and unavoidable impurities to 186 ° C. or higher and then cooling it to 186 ° C. or lower is repeated multiple times. wherein, in each cooling step, after the alloy is heated to 186 ° C. or higher, the cooling temperature line showing the change in the temperature of the alloy over time is a stable hexagonal crystal of Cu 6 Sn 5 at 186 ° C. or higher; The present invention relates to a method for manufacturing a solder joint, which passes through a stable orthorhombic mixed region at 186° C. or lower and is cooled such that the holding time in the temperature range of 160 to 137° C. is 96 to 305 seconds.
本発明の実施形態では、冷却温度線がＣｕ６Ｓｎ５の安定斜方晶と六方晶の前記混在領域を通過し、かつ、１７５～１２０℃の温度範囲での保持時間が４，０００秒以下となるように冷却してもよい。 In an embodiment of the present invention, the cooling temperature line passes through the mixed region of stable orthorhombic and hexagonal Cu 6 Sn 5 , and the holding time in the temperature range of 175 to 120° C. is 4,000 seconds or less. It may be cooled to
本発明の実施形態では、合金が、Ａｇ、Ｂｉ、Ｓｂ、Ｚｎ、Ｇｅ、Ｍｎ、Ｉｎから選択される少なくとも１種の元素を含んでもよい。 In embodiments of the invention, the alloy may contain at least one element selected from Ag, Bi, Sb, Zn, Ge, Mn, In.
本発明の実施形態では、Ｎｉの含量が、０．０３重量％以下であってもよい。 In an embodiment of the present invention, the Ni content may be 0.03 wt% or less.
本発明によれば、はんだ合金の溶融、冷却凝固を複数回行う場合であっても、作動時に相変態に伴う体積変化、及び体積変化に起因した歪や亀裂の発生などを抑制した信頼性の高い接合部を、生産性良く、形成可能なはんだ接合部の製造方法を提供することができる。 According to the present invention, even when the solder alloy is melted and cooled and solidified multiple times, the volume change accompanying the phase transformation during operation, and the occurrence of distortion and cracks due to the volume change are suppressed. It is possible to provide a method for manufacturing a solder joint that can form a high joint with good productivity.
以下、本発明の実施形態について説明する。 Embodiments of the present invention will be described below.
本発明に係るはんだ接合部の製造方法の実施形態では、Ｃｕ：０．３～７．６重量％、残部がＳｎ及び不可避不純物である合金を１８６℃以上に昇温した後１８６℃以下に冷却する冷却工程を複数回繰り返し行う。そして、複数回繰り返し行われる各冷却工程において、合金を１８６℃以上に昇温した後、合金の温度の経時変化を示す冷却温度線が、図１に示す、Ｃｕ６Ｓｎ５金属間化合物の１８６℃以上で安定な六方晶と、１８６℃以下で安定な斜方晶の混在領域を通過し、かつ、１６０～１３７℃の温度範囲の保持時間が９６～３０５秒になるように冷却する。 In an embodiment of the method for manufacturing a solder joint according to the present invention, an alloy containing 0.3 to 7.6% by weight of Cu and the balance being Sn and inevitable impurities is heated to 186° C. or higher and then cooled to 186° C. or lower. This cooling process is repeated several times. After heating the alloy to 186° C. or higher in each cooling step that is repeated multiple times, the cooling temperature line showing the change in the temperature of the alloy over time is shown in FIG. It passes through a mixed region of stable hexagonal crystals and stable orthorhombic crystals at 186° C. or lower, and is cooled so that the holding time in the temperature range of 160 to 137° C. is 96 to 305 seconds.
このように、複数回行われる冷却工程において、特許文献１に記載の発明の場合とは異なり、１６０～１３７℃での温度保持時間が、９６～３０５秒であっても、この条件下で、合金の温度の経時変化を示す冷却温度線が、図１に示す、Ｃｕ６Ｓｎ５の安定斜方晶と六方晶の混在領域を通過していれば、信頼性の高い接合部が形成される。これは、（１）１３７～１６０℃の温度で、例えば４０００秒程度保持すると、Ｃｕ６Ｓｎ５の相変態は起こるものの、結晶が成長することで亀裂（クラック）が発生し、かえってクラックの発生量が増加すること、（２）図１に示す各結晶相の境界を表すＴＴＴ曲線のうち、斜方晶と六方晶の混合領域と１００％準安定η－Ｃｕ６Ｓｎ５領域（六方晶領域）との境界を示すＴＴＴ曲線（以下、「混晶ＴＴＴ曲線」と称する場合がある。）を越すと急激に相変態が起こり短時間でも斜方晶の割合が多くなり得ること、等が要因と考えられる。尚、１３７～１６０℃での保持時間を長くすることでクラックの発生量が増加すること、短時間で相変態が起こることは、実験により確認している。
In this way, in the cooling process performed multiple times, unlike the invention described in
冷却工程では、合金を１８６℃以上に昇温した後は、合金の温度の経時変化を示す冷却温度線がＣｕ６Ｓｎ５の安定斜方晶と六方晶の混在領域を通過し、かつ、１６０～１３７℃の温度範囲の保持時間が９６～３０５秒となるように冷却すればよい。信頼性を向上する観点から当該温度範囲での保持時間（経過時間）は、１００秒以上が好ましく、１３０秒以上がより好ましい。この際の温度と時間の関係は、逆進的な昇温をさせない限りは、特に限定はない。漸次降温してもよいし、一定温度に保持する時間を適宜設けてもよい。言い換えると降温速度を一定にしてもよいし、任意に変化させてもよい。また、より効率的な冷却を行う観点から、冷却温度線がＣｕ６Ｓｎ５の安定斜方晶と六方晶の混在領域を通過し、かつ、１７５～１２０℃の温度範囲の保持時間が４，０００秒以下となるように冷却してもよい。 In the cooling step, after heating the alloy to 186 ° C. or higher, the cooling temperature line showing the change in the temperature of the alloy with time passes through the stable orthorhombic and hexagonal stable mixed region of Cu6Sn5, and 160 to 137 ° C. It is sufficient to cool so that the holding time in the temperature range is 96 to 305 seconds. From the viewpoint of improving reliability, the holding time (elapsed time) in the temperature range is preferably 100 seconds or longer, more preferably 130 seconds or longer. The relationship between temperature and time at this time is not particularly limited as long as the temperature is not raised in a regressive manner. The temperature may be gradually lowered, or the time for holding at a constant temperature may be provided as appropriate. In other words, the rate of temperature drop may be constant, or may be changed arbitrarily. In addition, from the viewpoint of more efficient cooling, the cooling temperature line passes through the stable orthorhombic and hexagonal mixed region of Cu6Sn5, and the holding time in the temperature range of 175 to 120 ° C. is 4,000 seconds or less. It may be cooled to
また、１８６℃以上に昇温後１６０℃に至るまで及び１３７℃未満になった後は、効率的に接合部を冷却することができれば降温速度は特に限定はない。１８６℃以上に昇温後１６０℃に至るまではＣｕ６Ｓｎ５の安定斜方晶と六方晶の混在領域を通過させる観点から、１８６℃以上に昇温して冷却を開始した後、１４０～１６０℃で図１に示す混晶ＴＴＴ曲線と効率的に交差するように、逆進的に昇温させることなく合金の冷却温度線を制御するのが好ましい。 Further, after the temperature is raised to 186° C. or higher, the temperature is lowered to 160° C. and after the temperature is lowered to less than 137° C., the cooling rate is not particularly limited as long as the joint can be efficiently cooled. From the viewpoint of allowing Cu6Sn5 to pass through a mixed region of stable orthorhombic and hexagonal crystals until the temperature rises to 186 ° C. or higher and reaches 160 ° C., after the temperature is raised to 186 ° C. or higher and cooling is started, at 140 to 160 ° C. It is preferable to control the alloy cooling temperature line without regressive heating so that it effectively intersects the mixed crystal TTT curve shown in FIG.
冷却工程の繰り返し回数は、はんだ接合を行う基材等の特性等により適宜決定することができるが、繰り返し回数が多くなると、接合強度が低下する傾向にあるため、極端に回数を多くするのは望ましくない。また、繰り返し時の冷却条件は、同じでもよいし、異なってもよい。 The number of repetitions of the cooling process can be appropriately determined according to the properties of the base material to be soldered. Undesirable. Also, the cooling conditions during the repetition may be the same or different.
合金の成分組成は、Ｃｕ０．３～７．６重量％、残部がＳｎ及び不可避不純物であってよい。つまり、残部は実質的にＳｎが９９．７～９２．４重量％で微量の不可避不純部を含み得る。Ｃｕの含量が０．３重量％未満である場合、良好なはんだ接合部を形成することができなくなる傾向にある。７．６重量％を超えると、Ｃｕ３Ｓｎ金属間化合物も形成され、Ｃｕ６Ｓｎ５の生成量が相対的に低下する。そのため、本発明を適用する意義が低下する。 The composition of the alloy may be 0.3 to 7.6% by weight of Cu, with the balance being Sn and unavoidable impurities. In other words, the balance is substantially 99.7 to 92.4% by weight of Sn and may contain a small amount of unavoidable impurities. If the Cu content is less than 0.3% by weight, it tends to be difficult to form good solder joints. Above 7.6% by weight, a Cu3Sn intermetallic compound is also formed and the amount of Cu6Sn5 produced is relatively reduced. Therefore, the significance of applying the present invention is reduced.
合金には、Ｃｕ６Ｓｎ５の生成を大きく阻害しなければ、ＳｎとＣｕ以外に他の金属を含んでもよい。このような金属元素としては、例えば、Ａｇ、Ｂｉ、Ｓｂ、Ｚｎ、Ｇｅ、Ｍｎ、Ｉｎ等が挙げられる。これらは、１種含んでもよいし、２種以上含んでもよい。なお、Ｎｉを０．０３重量％より多く含むと前述のような冷却工程を経ることなく良好な接合部を形成可能である。そのため、前述の冷却工程を意義あらしめる観点からは、Ｎｉの含量は、０．０３重量％以下が望ましく、０．０２重量％以下がより好ましい。 The alloy may contain other metals besides Sn and Cu as long as they do not significantly inhibit the formation of Cu6Sn5. Examples of such metal elements include Ag, Bi, Sb, Zn, Ge, Mn, and In. These may contain 1 type, and may contain 2 or more types. In addition, when the Ni content is more than 0.03% by weight, it is possible to form a good joint without going through the cooling process as described above. Therefore, from the viewpoint of making the above-described cooling step meaningful, the Ni content is preferably 0.03 wt % or less, more preferably 0.02 wt % or less.
以上のような実施形態に係るはんだ接合部の製造方法は、Ｓｎ－Ｃｕはんだ合金やＣｕ６Ｓｎ５の生成を大きく阻害しない他の金属を含むＳｎ－Ｃｕ系はんだ合金を用いて行われる各種のはんだ付けにおいて好適に適用可能である。 The method for manufacturing a solder joint according to the embodiment as described above can be used in various soldering processes using Sn--Cu solder alloys and Sn--Cu solder alloys containing other metals that do not greatly hinder the formation of Cu6Sn5. Applicability is preferable.
実施例により、本願発明の実施形態をより詳細に説明する。 EXAMPLES Embodiments of the present invention will be described in more detail by means of examples.
（試験例１ａ～４ｃ）
＜はんだ接合部の製造＞
Ｃｕが０．７重量％、残部がＳｎと不可避不純物であるＳｎ－０．７Ｃｕ合金（株式会社日本スペリア社製、ＳＣ０７）を用い、粒子径５００μｍのはんだボールを作製した。銅箔基板の実装箇所に「フラックスＲＭ－５」（株式会社日本スぺリア製）を塗布した後、はんだボールを搭載した。リフロー装置（Ｍａｎｎｃｏｒｐ社製、ＢＴ３００）を用いて、窒素雰囲気下で、以下の温度履歴となるようにはんだ接合部の製造を行った。
(Test Examples 1a to 4c)
<Manufacturing of solder joints>
A solder ball with a particle diameter of 500 μm was produced using a Sn-0.7Cu alloy (manufactured by Nihon Superior Co., Ltd., SC07) containing 0.7% by weight of Cu and the balance being Sn and inevitable impurities. After applying “Flux RM-5” (manufactured by Nihon Speria Co., Ltd.) to the mounting locations of the copper foil substrate, solder balls were mounted. Using a reflow apparatus (manufactured by Manncorp, BT300), solder joints were manufactured in a nitrogen atmosphere so as to have the following temperature history.
その後、室温から約５分間で約２４０℃まで昇温した後、表１のような条件で冷却した。リフローを繰り返す場合は、常温まで冷却後、同様の操作を繰り返した。常温に冷却後、ＩＰＡ（イソプロピルアルコール）にて洗浄して、フラックスを除去後、後述する評価を行った。尚、各条件において、はんだボールは２０箇所に実装し、それぞれ下記の評価を行った。また、表１より、試験例１～４の１６０～１３７℃の経過時間はそれぞれ、９５ｓ、１５５ｓ、１７４ｓ、３０５ｓである。 Thereafter, the temperature was raised from room temperature to about 240° C. in about 5 minutes, and then cooled under the conditions shown in Table 1. When reflow was repeated, the same operation was repeated after cooling to room temperature. After cooling to normal temperature, it was washed with IPA (isopropyl alcohol) to remove the flux, and then evaluated as described later. In each condition, 20 solder balls were mounted, and the following evaluations were performed. Further, from Table 1, the elapsed times of 160 to 137° C. in Test Examples 1 to 4 are 95 s, 155 s, 174 s and 305 s, respectively.
＜評価＞
各試験例１ａ～４ｃで得られたはんだ接合部２０箇所をインパクトシェア試験機（ＤＡＧＥ社製 ４０００ＨＳ）にセットし、２，０００ｍｍ／秒でのせん断負荷応力を測定した。せん断負荷応力の最大値の平均値を接合強度とした。評価結果を図２に示す。図２には、接合強度の結果（図２ａ）と、冷却工程を１回行った時の接合強度に対する変化率の算出結果（図２ｂ）を示した。
<Evaluation>
Twenty solder joints obtained in each of Test Examples 1a to 4c were set in an impact shear tester (4000HS manufactured by DAGE) to measure shear load stress at 2,000 mm/sec. The average value of the maximum values of the shear load stress was taken as the bonding strength. The evaluation results are shown in FIG. FIG. 2 shows the result of bonding strength (FIG. 2a) and the calculation result of the rate of change with respect to the bonding strength when the cooling process was performed once (FIG. 2b).
（試験例５ａ～８ｃ）
はんだ合金を、Ｃｕが０．５重量％、Ａｇが３．０重量％、残部がＳｎと不可避不純物であるＳｎ－３Ａｇ－０．５Ｃｕ合金（株式会社日本スペリア社製、ＳＡＣ３０５）を用いた以外は、それぞれ試験例１ａ～４ｃと同様にしてはんだ接合部を製造し、評価を行った。評価結果を図３ａ、ｂに示す。
(Test Examples 5a to 8c)
The solder alloy is 0.5% by weight of Cu, 3.0% by weight of Ag, and the balance is Sn and Sn-3Ag-0.5Cu alloy (manufactured by Nihon Superior Co., Ltd., SAC305), which is an inevitable impurity. produced and evaluated solder joints in the same manner as in Test Examples 1a to 4c. The evaluation results are shown in Figures 3a,b.
図２、３から分かるように、所定の条件を満たす冷却工程（試験例２～４）を行うことで、冷却工程を１回のみを行った場合に比べて、複数回行った場合の接合強度の低下を抑制することが可能であることが分かる。
As can be seen from FIGS. 2 and 3, by performing the cooling process (test examples 2 to 4) that satisfies the predetermined conditions, the bonding strength in the case of performing the cooling process multiple times is higher than in the case of performing the cooling process only once. It can be seen that it is possible to suppress the decrease in
Claims (3)
各冷却工程において、合金を１８６℃以上に昇温した後、合金の温度の経時変化を示す冷却温度線がＣｕ６Ｓｎ５の１８６℃以上で安定な六方晶と、１８６℃以下で安定な斜方晶の混在領域を通過し、かつ、１６０～１３７℃の温度範囲での保持時間が１５５～３０５秒となるように冷却する、はんだ接合部の製造方法。 Cu: 0.3 to 7.6% by weight, the balance being Sn and unavoidable impurities A method for manufacturing a solder joint in which the cooling process of heating the alloy to 186 ° C. or higher and then cooling it to 186 ° C. or lower is repeated multiple times. There is
In each cooling step, after heating the alloy to 186 ° C. or higher, the cooling temperature line showing the change in the temperature of the alloy over time is a hexagonal crystal that is stable at 186 ° C. or higher and an oblique crystal that is stable at 186 ° C. or lower. A method for producing a solder joint, which passes through a cubic mixed region and is cooled in a temperature range of 160 to 137° C. for a holding time of 155 to 305 seconds.
3. The method for producing a solder joint according to claim 1, comprising at least one element selected from Ag, Bi, Sb, Zn, Ge, Mn and In.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005150655A (en) | 2003-11-20 | 2005-06-09 | Matsushita Electric Ind Co Ltd | Lead frame, semiconductor device using the same, and method for packaging semiconductor device |
| WO2009051255A1 (en) | 2007-10-19 | 2009-04-23 | Nihon Superior Sha Co., Ltd. | Solder joint |
| WO2013002112A1 (en) | 2011-06-29 | 2013-01-03 | 株式会社日本スペリア社 | Process for producing solder joint with improved reliability |
| WO2018096917A1 (en) | 2016-11-22 | 2018-05-31 | 千住金属工業株式会社 | Soldering method |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005150655A (en) | 2003-11-20 | 2005-06-09 | Matsushita Electric Ind Co Ltd | Lead frame, semiconductor device using the same, and method for packaging semiconductor device |
| WO2009051255A1 (en) | 2007-10-19 | 2009-04-23 | Nihon Superior Sha Co., Ltd. | Solder joint |
| WO2009051181A1 (en) | 2007-10-19 | 2009-04-23 | Nihon Superior Sha Co., Ltd. | Lead-free solder alloy |
| WO2013002112A1 (en) | 2011-06-29 | 2013-01-03 | 株式会社日本スペリア社 | Process for producing solder joint with improved reliability |
| WO2018096917A1 (en) | 2016-11-22 | 2018-05-31 | 千住金属工業株式会社 | Soldering method |
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