JP2017189793A - Au-Sn-BASED SOLDER ALLOY - Google Patents

Au-Sn-BASED SOLDER ALLOY Download PDF

Info

Publication number
JP2017189793A
JP2017189793A JP2016079970A JP2016079970A JP2017189793A JP 2017189793 A JP2017189793 A JP 2017189793A JP 2016079970 A JP2016079970 A JP 2016079970A JP 2016079970 A JP2016079970 A JP 2016079970A JP 2017189793 A JP2017189793 A JP 2017189793A
Authority
JP
Japan
Prior art keywords
mass
solder
less
solder alloy
alloy
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2016079970A
Other languages
Japanese (ja)
Inventor
井関 隆士
Takashi Izeki
隆士 井関
昌彦 小室
Masahiko Komuro
昌彦 小室
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Metal Mining Co Ltd
Original Assignee
Sumitomo Metal Mining Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Metal Mining Co Ltd filed Critical Sumitomo Metal Mining Co Ltd
Priority to JP2016079970A priority Critical patent/JP2017189793A/en
Publication of JP2017189793A publication Critical patent/JP2017189793A/en
Pending legal-status Critical Current

Links

Images

Abstract

PROBLEM TO BE SOLVED: To provide an Au-Sn-based solder alloy keeping a solder shape when being soldered, increasing the ratio of the solder substantially contributing to soldering and further capable of suppressing the occurrence of voids.SOLUTION: In a first Au-Sn-based solder alloy, the content of Sn is 18.5 mass% or more and 23.5 mass% or less, the content of Bi is 0.01 mass% or more and less than 0.5 mass% when contained and the balance is Au except an element inevitably contained in production. In a second Au-Sn-based solder alloy, the content of Sn is 18.5 mass% or more and 23.5 mass% or less, the content of Bi is 0.01 mass% or more and less than 0.50 mass%, the content of one or more kinds among Mg and Sb is 0.01 mass% or more and 2.00 mass% or less in the case of Mg and more than 1.00 mass% and 5.00 mass% or less in the case of Sb and the balance is Au except an element inevitably contained in production.SELECTED DRAWING: None

Description

本発明は、はんだ接合時に優れた形状維持性を示し、はんだ接合に実質的に寄与するはんだ体積率が高く、かつボイドが発生しにくいAuを主成分とするAu−Snはんだ合金、および該はんだ合金を用いて封止または接合された電子部品等に関する。   The present invention provides an Au—Sn solder alloy mainly composed of Au, which exhibits excellent shape maintaining property during solder bonding, has a high solder volume ratio that contributes substantially to solder bonding, and is less likely to generate voids, and the solder The present invention relates to an electronic component sealed or bonded using an alloy.

近年、環境に有害な化学物質に対する規制がますます厳しくなってきており、この規制は電子部品などを基板に接合する目的で使用されるはんだ材料に対しても例外ではない。はんだ材料には古くから鉛(Pb)が主成分として使われ続けてきたが、すでにRoHS指令などで鉛は規制対象物質になっている。このため、Pbフリーはんだ材料の開発が各種機関で進められており、高温用のPbフリーはんだ材料では、高価なAu−Sn合金やAu−Ge合金などが水晶デバイス、SAWフィルター、MEMS等ですでに実用化されている。   In recent years, regulations on chemical substances harmful to the environment have become stricter, and this regulation is no exception for solder materials used for the purpose of joining electronic components and the like to substrates. Lead (Pb) has been used as a main component for solder materials for a long time, but lead has already become a regulated substance under the RoHS directive and the like. For this reason, development of Pb-free solder materials is being promoted by various organizations, and for high-temperature Pb-free solder materials, expensive Au-Sn alloys and Au-Ge alloys are crystal devices, SAW filters, MEMS, etc. Has been put to practical use.

Au−Sn合金はAu−20質量%Sn(80質量%のAuと20質量%のSnから構成されることを意味しており、以降においても同様)の組成で共晶点となり、その融点は280℃である。一方、Au−Ge合金はAu−12.5質量%Geの組成で共晶点となり、その融点は356℃である。これらAu系はんだ合金は硬くて脆い特性を有しており、特にAu−Sn合金は粘りがないためきれいに破断させることができ、薄くて小さく加工することができるので枠形状として使用されることが多い。一方、Au−Ge合金は比較的加工し易いボール形状で使用されることが多い。   The Au-Sn alloy has a composition of Au-20% by mass Sn (meaning that it is composed of 80% by mass Au and 20% by mass Sn, and so on), and has a eutectic point. 280 ° C. On the other hand, the Au—Ge alloy has an eutectic point with a composition of Au-12.5 mass% Ge, and its melting point is 356 ° C. These Au-based solder alloys have hard and brittle characteristics, and in particular, Au-Sn alloys are not sticky and can be broken cleanly, and can be processed thinly and smallly, so that they can be used as frame shapes. Many. On the other hand, Au—Ge alloys are often used in a ball shape that is relatively easy to process.

このようなAu系はんだに関しては、例えば特許文献1には、Au/Snロウ材の表面粗さを制御して濡れ性を改善する技術が開示されており、具体的にはJISB0601で規定される表面粗さRaで0.01〜5μmの範囲内にすることによって、濡れ性に優れた金錫合金ロウ材を提供する技術が示されている。また、特許文献2には、Au/Snはんだペースト内の酸素濃度の管理および粒径を小さくすることによって、濡れ性を制御する技術が開示されている。   With regard to such an Au-based solder, for example, Patent Document 1 discloses a technique for improving the wettability by controlling the surface roughness of an Au / Sn brazing material, and is specifically defined in JIS B0601. A technique for providing a gold-tin alloy brazing material excellent in wettability by setting the surface roughness Ra within a range of 0.01 to 5 μm is shown. Patent Document 2 discloses a technique for controlling wettability by controlling the oxygen concentration in the Au / Sn solder paste and reducing the particle size.

また、特許文献3には、ボイド発生の少ないAu−Sn合金はんだペーストとして、「Sn:14〜30質量%を含有し、さらにBi:0.5〜5質量%、In:0.1〜5質量%およびSb:0.01〜1質量%の内のいずれかを含有し、残りがAuおよび不可避不純物からなる成分組成を有するAu−Sn合金はんだ粉末とフラックスとの混合体からなり、前記混合体は、フラックス:5〜25質量%含有する」はんだペーストが開示されている。   Patent Document 3 discloses that “Au: Sn alloy containing 14 to 30% by mass, Bi: 0.5 to 5% by mass, In: 0.1 to 5% as an Au—Sn alloy solder paste with less void generation. And a mixture of Au-Sn alloy solder powder having a component composition consisting of Au and inevitable impurities and a flux, containing any one of the mass% and Sb: 0.01 to 1 mass%. The body contains flux: 5-25% by weight "solder paste is disclosed.

特開2001−150182号公報JP 2001-150182 A 特開2003−260588号公報JP 2003-260588 A 特開2008−137018号広報Japanese Laid-Open Patent Publication No. 2008-137018

近年、電子機器の小型化、薄型化に伴い、水晶デバイスやSAWフィルターなどの電子装置においては、外形が小さくて薄型のものが求められている。そのため、これら電子装置に使用するはんだ合金は、はんだ融解時に高い精度で形状を制御可能であることが望ましい。例えば、水晶振動子の封止用などに多用されるAu−Sn合金は、封止用蓋部の周縁部でシールするため枠形状で使用されることが多いが、その融解時に接合面がAu−Sn合金によって均一に濡れなければリーク不良などの不具合が発生するおそれがある。   In recent years, electronic devices such as crystal devices and SAW filters have been required to be small and thin as electronic devices have become smaller and thinner. Therefore, it is desirable that the shape of the solder alloy used in these electronic devices can be controlled with high accuracy when the solder is melted. For example, an Au-Sn alloy that is frequently used for sealing a crystal resonator is often used in a frame shape for sealing at the peripheral edge of the sealing lid, but the bonding surface is Au at the time of melting. -If the Sn alloy is not evenly wetted, there is a risk that problems such as leakage failure may occur.

また、Au−Snはんだ合金を半導体素子の接合に使用する場合は、接合面が均一に濡れなければ十分な接合強度が得られなかったり、被接合体である半導体素子が傾いて接合信頼性が著しく低下したりするおそれがある。さらに濡れが不均一になって部分的な濡れ広がりや流れ出しが顕著になると、はんだ接合に実質的に寄与するはんだの体積が小さくなり、熱応力等による歪みを十分に緩和できなくなってクラック等が発生しやすくなったり、接合信頼性が低下したりなどの問題が生じることもある。このように、Au−Snはんだ合金においては濡れ性が特に重要な特性と言える。   In addition, when an Au—Sn solder alloy is used for bonding semiconductor elements, sufficient bonding strength cannot be obtained unless the bonding surface is uniformly wetted, or the bonding reliability of the bonded semiconductor element is tilted. There is a risk of a significant decrease. Furthermore, when wetting becomes uneven and partial wetting spread and flow out become prominent, the volume of solder that substantially contributes to solder bonding becomes smaller, and distortion due to thermal stress, etc. cannot be sufficiently relaxed, cracks, etc. There are cases where problems such as easy generation and reduced bonding reliability occur. Thus, it can be said that wettability is a particularly important characteristic in the Au—Sn solder alloy.

上記した種々の問題は、前述した電子機器の小型化、薄型化によって顕在化する傾向にある。すなわち、電子機器の小型化、薄型化に伴ってはんだ合金と水晶振動子等の電子部品との間隔がより狭くなり、上記したはんだの不均一な濡れ広がりや流れ出しにより、はんだ合金と水晶振動子とが接触するリスクが高まっている。また、電子機器の小型化、薄型化に伴い、はんだ合金自体のサイズや厚さも制限されるため、上記した不均一な濡れ広がりや接合面以外への流れ出しが生ずるとはんだ接合部のはんだの体積の減少割合がより著しくなり、はんだ接合の信頼性が損なわれる問題がより一層顕著になってきている。なお、上記した部分的な濡れ広がりの程度は、はんだとの接合面に平行な濡れ広がり前のはんだの断面の全面積に対して25%以下に抑えるのが一般に好ましい。   The various problems described above tend to become apparent as the above-described electronic devices are reduced in size and thickness. In other words, as the electronic equipment becomes smaller and thinner, the distance between the solder alloy and the electronic component such as the crystal resonator becomes narrower. The risk of contact with is increasing. In addition, as electronic devices become smaller and thinner, the size and thickness of the solder alloy itself are also limited. Therefore, if the above-mentioned uneven wetting spreads or flows out of the joint surface, the solder volume of the solder joint is reduced. The rate of decrease of the solder becomes more remarkable, and the problem that the reliability of the solder joint is impaired is becoming more remarkable. The degree of partial wetting and spreading described above is generally preferably 25% or less with respect to the total area of the cross section of the solder before wetting and spreading parallel to the joint surface with the solder.

このような状況の下、特許文献1の技術は表面粗さが粗ければ表面積が大きくなり、成分中のSnの酸化が起こる割合も高くなるため、表面粗さを細かく、すなわち表面積を小さくして成分中のSnの酸化する割合を抑え、これにより濡れ性を向上させるものであると考えられる。しかしながら、特許文献1に示すような表面粗さ0.01〜5μmという広い範囲に亘ってロウ材が同じように優れた濡れ性を示すとは考えにくい。すなわち表面粗さが500倍粗くなると、ロウ材表面に存在する酸化物の割合が桁違いに多くなると考えられるため、濡れ性が大きく悪化することが容易に推測できる。   Under such circumstances, the technique of Patent Document 1 increases the surface area if the surface roughness is rough, and also increases the rate of oxidation of Sn in the component. Therefore, the surface roughness is reduced, that is, the surface area is reduced. Therefore, it is considered that the ratio of oxidation of Sn in the component is suppressed, thereby improving the wettability. However, it is unlikely that the brazing material exhibits the same excellent wettability over a wide range of surface roughness of 0.01 to 5 μm as shown in Patent Document 1. That is, when the surface roughness becomes 500 times rough, it is considered that the ratio of the oxide present on the surface of the brazing material is increased by an order of magnitude, so it can be easily estimated that the wettability is greatly deteriorated.

しかも、表面粗さが粗くなると、Au−Snロウ材とロウ付けする基板との間には空間が生じやすくなるため、表面粗さが500倍粗い方が当然大きな空間が形成され、溶融時にこの空間にボイドが生じてロウ付け後の製品の信頼性が大きく損なわれるおそれがある。逆に、表面粗さが細かくなると上記したように濡れ性が良くなる傾向にあるが、ロウ材としてはそれだけでは不十分である。すなわち、表面粗さよりも基板の金属およびロウ材における組成や組織の均一性が重要であり、これらの組成や組織が均一でなければ接合時に生成される合金は部分部分で異なってしまい、濡れ広がりや接合性にばらつきが生じてしまう。   Moreover, when the surface roughness is increased, a space is likely to be generated between the Au—Sn brazing material and the substrate to be brazed. There is a risk that voids are generated in the space and the reliability of the product after brazing is greatly impaired. On the contrary, when the surface roughness becomes finer, the wettability tends to be improved as described above, but that is not sufficient as a brazing material. In other words, the uniformity of the composition and structure of the metal and brazing material of the substrate is more important than the surface roughness. If these compositions and structures are not uniform, the alloy produced at the time of joining will be different in each part, and wetting and spreading will occur. And variations in bondability.

また、特許文献2に示すように、Au−Snはんだペースト自体の酸素濃度を上げると、はんだ溶融時に表面酸化膜の生成が顕著になり、濡れ性に影響を及ぼす。この場合、過度の濡れ広がりを抑制することができるものの、酸化膜によりボイドが発生したり気密性が維持できなかったりするおそれがある。また、クラック等を誘発するなどの品質上の問題を招くおそれもある。   Moreover, as shown in Patent Document 2, when the oxygen concentration of the Au—Sn solder paste itself is increased, the generation of a surface oxide film becomes remarkable when the solder is melted, which affects wettability. In this case, although excessive wetting and spreading can be suppressed, voids may be generated by the oxide film or airtightness may not be maintained. In addition, there is a risk of incurring quality problems such as inducing cracks.

さらに、平均粒径を50〜100μmから10〜35μmに小さくすると、Sn微粒子の単位質量当たりの表面酸化膜の量が増えることによる問題が生じるおそれがある。すなわち、一般的に表面酸化膜が破れないと溶けた内部の溶融金属が流れ出さないため、一旦表面が酸化した微粒子は融点に達しても溶体が流れ出にくくなる。さらには実質的な溶融温度のばらつきや組成ばらつきが大きくなって、微粒子が均一に溶けにくくなるため、封止不良や接合不良の原因になって製品としての信頼性が低下するおそれがある。従って、特許文献2の技術は高気密性が要求されるSAWフィルターや水晶デバイスなどの封止、あるいは半導体素子などの基板への接合の用途には適さないと考えられる。   Furthermore, if the average particle size is reduced from 50 to 100 μm to 10 to 35 μm, there may be a problem that the amount of the surface oxide film per unit mass of the Sn fine particles increases. That is, generally, if the surface oxide film is not broken, the melted internal molten metal does not flow out. Therefore, even if the fine particles whose surface is once oxidized reach the melting point, the solution does not easily flow out. Further, substantial melting temperature variation and composition variation become large, and the fine particles are difficult to be dissolved uniformly. This may cause sealing failure and bonding failure, thereby reducing the reliability of the product. Therefore, it is considered that the technique of Patent Document 2 is not suitable for use in sealing a SAW filter or a crystal device that requires high airtightness or bonding to a substrate such as a semiconductor element.

上記したように、はんだ合金の濡れ性ははんだ接合において重要な要素であるが、それ以外にも重要な要求事項としてボイドの低減が挙げられる。すなわちボイド率が高くなると十分な接合強度が得られなかったり、クラックの起点になってクラックが発生し易くなってしまったり、放熱性が低下したりしてしまう。また、封止用途においてはリークが生じ易くなる。   As described above, the wettability of the solder alloy is an important factor in solder joining, but other important requirements include reduction of voids. That is, if the void ratio increases, sufficient bonding strength cannot be obtained, cracks are easily generated at the starting point of cracks, and heat dissipation is reduced. In addition, leakage tends to occur in sealing applications.

ボイド発生が抑えられたAu−Sn合金はんだペーストを開示する特許文献3には、BiやSbなどはAu−Sn合金の溶融時の表面張力を低下させるために添加するとの記載があるが、ボイド発生が少なくなる理由については記載がない。さらにBiは半金属的な性質を有しており比較的脆いため、はんだ中に少量含有させることは問題ないが、含有量が多くなるとはんだが脆くなってしまい、高い応力緩和性や接合信頼性を得るのが困難になる。   Patent Document 3, which discloses an Au—Sn alloy solder paste in which generation of voids is suppressed, describes that Bi, Sb, and the like are added to reduce the surface tension during melting of the Au—Sn alloy. There is no description about the reason why the occurrence is reduced. Furthermore, Bi has semi-metallic properties and is relatively brittle, so it is not a problem to add a small amount in the solder. However, if the content is increased, the solder becomes brittle, and high stress relaxation properties and bonding reliability. It becomes difficult to get.

上記したように、特に高い信頼性が要求される水晶デバイス、SAWフィルター、またはMEMS等で使用する高温用のPbフリーはんだ材料にはボイドの発生や封止不良などがあると安定した使用ができなくなるため、これらに使用するAu系はんだ材料には良好な濡れ性を有することが求められている。特に高い気密性や接合信頼性を必要とする用途では、良好な濡れ性を有することに加えてはんだ接合の際に有効なはんだ体積(ボリューム)が維持されること、すなわち、使用したはんだ合金のほとんどがはんだ接合に寄与することを要求される場合が多い。このように、水晶デバイス等の特に高い信頼性が要求される電子部品に用いるはんだには、はんだ接合時における適切な濡れ性と有効なはんだ体積の維持という一見相反する機能が求められている。   As described above, Pb-free solder materials for high temperatures used in quartz devices, SAW filters, MEMS, etc. that require particularly high reliability can be used stably if there are voids or poor sealing. Therefore, Au-based solder materials used for these are required to have good wettability. Especially in applications that require high airtightness and bonding reliability, in addition to having good wettability, an effective solder volume is maintained during solder bonding, that is, the solder alloy used Most are often required to contribute to solder joints. Thus, a solder used for an electronic component such as a quartz device that requires particularly high reliability is required to have a seemingly contradictory function of maintaining appropriate wettability and effective solder volume during solder joining.

上記した状況の下、本発明者らは特に高い信頼性が要求される水晶デバイス等の電子部品用のAu−Sn系はんだ合金について鋭意研究を重ねた結果、はんだ接合時にはんだが部分的に濡れ広がることや、逆に部分的に濡れずに収縮することなどの現象を抑えて接合面にはんだがほぼ均一に濡れ広がるようにすることによって、高い接合信頼性を有する接合が可能になるとの着想の下、さらに研究を進めたところ、Au−Snはんだ合金にBiを必須元素として含有させ、さらに必要に応じてMgおよびSbのうちの1種以上を含有させることにより、均一な濡れ性が得られることを見出し、本発明を完成するに至った。   Under the circumstances described above, the present inventors have conducted extensive research on Au-Sn solder alloys for electronic components such as quartz devices that require particularly high reliability. As a result, the solder is partially wetted during solder joining. The idea that bonding with high bonding reliability becomes possible by suppressing the phenomenon of spreading and conversely shrinking without partial wetting, and allowing solder to spread almost uniformly on the bonding surface. As a result of further research, uniform wettability was obtained by including Bi as an essential element in an Au—Sn solder alloy and further including at least one of Mg and Sb as required. As a result, the present invention has been completed.

すなわち、本発明に係る第1のAu−Sn系はんだ合金は、Snを18.5質量%以上23.5質量%以下含有し、Biを0.01質量%以上0.5質量%未満含有し、残部が製造上不可避に含まれる元素を除きAuから構成されることを特徴とする。また、本発明に係る第2のAu−Sn系はんだ合金は、Snを18.5質量%以上23.5質量%以下含有し、Biを0.01質量%以上0.50質量%未満含有し、さらにMgおよびSbのうちの1種以上を、Mgの場合は0.01質量%以上2.00質量%以下、Sbの場合は1.00質量%を超え5.00質量%以下含有し、残部が製造上不可避に含まれる元素を除きAuから構成されることを特徴とする。   That is, the first Au—Sn solder alloy according to the present invention contains 18.5% by mass to 23.5% by mass of Sn and Bi of 0.01% by mass to less than 0.5% by mass. The remainder is composed of Au except for elements inevitably included in production. In addition, the second Au—Sn solder alloy according to the present invention contains Sn of 18.5% by mass to 23.5% by mass and Bi of 0.01% by mass to less than 0.50% by mass. Further, at least one of Mg and Sb is contained in the case of Mg, 0.01 mass% or more and 2.00 mass% or less, and in the case of Sb, more than 1.00 mass% and 5.00 mass% or less, The remainder is composed of Au except for elements inevitably included in the production.

本発明によれば、はんだ接合時に従来のAu系はんだよりも優れた形状維持性が得られるうえ、使用するはんだのうち実質的にはんだ接合に寄与するはんだの割合が高いAu−Sn系はんだ合金を提供できる。よって、このはんだ合金を水晶デバイス、SAWフィルター、MEMSなどの極めて高い信頼性を要求される電子部品等の接合や封止に用いることによって、これら電子部品を備えた電子機器の信頼性をより一層高めることが可能になる。   According to the present invention, an Au—Sn solder alloy having a shape retention superior to that of a conventional Au solder at the time of solder joining and a high proportion of solder that contributes substantially to the solder joint among the solders used. Can provide. Therefore, by using this solder alloy for bonding and sealing of electronic parts such as crystal devices, SAW filters, MEMS, etc. that require extremely high reliability, the reliability of electronic equipment equipped with these electronic parts is further increased. It becomes possible to increase.

はんだ合金の試料が接合されたAuめっきCu基板をはんだ試料側から見た模式的な平面図である。It is the typical top view which looked at Au plating Cu substrate to which a sample of solder alloy was joined from the solder sample side. 封止用容器と封止用蓋とをはんだ合金の試料で封止した状態を示す模式的な縦断面図である。It is a typical longitudinal cross-sectional view which shows the state which sealed the container for sealing and the lid | cover for sealing with the sample of the solder alloy.

以下、本発明のAu−Sn系はんだ合金の実施形態について説明する。本発明の第1の実施形態のAu−Sn系はんだ合金は、必須元素としてSnを18.5質量%以上23.5質量%以下、およびBiを0.01質量%以上0.5質量%未満含有し、残部が製造上不可避に含まれる元素を除きAuからなる。また、本発明の第2の実施形態のAu−Sn系はんだ合金は、Snを18.5質量%以上23.5質量%以下含有し、Biを0.01質量%以上0.50質量%未満含有し、さらにMgおよびSbのうちの1種以上を、Mgの場合は0.01質量%以上2.00質量%以下、Sbの場合は1.00質量%を超え5.00質量%以下含有し、残部が製造上不可避に含まれる元素を除きAuからなる。   Hereinafter, embodiments of the Au—Sn solder alloy of the present invention will be described. The Au—Sn solder alloy according to the first embodiment of the present invention has Sn as an essential element of 18.5% by mass to 23.5% by mass and Bi of 0.01% by mass to less than 0.5% by mass. It is made of Au except for elements which are contained and the remainder is inevitably included in the production. Further, the Au—Sn based solder alloy of the second embodiment of the present invention contains Sn of 18.5% by mass to 23.5% by mass and Bi of 0.01% by mass to less than 0.50% by mass. Further, one or more of Mg and Sb are contained, and in the case of Mg, 0.01% by mass to 2.00% by mass, and in the case of Sb, more than 1.00% by mass and 5.00% by mass or less The remainder is made of Au except for elements that are inevitably included in production.

上記組成のAu−Sn系はんだ合金であれば、はんだ接合時に優れた形状維持性を示し、使用したはんだのうちはんだ接合に実質的に寄与するはんだの割合(以降、有効はんだ体積率とも称する)が高く、かつボイドが発生しにくいはんだ合金が得られる。すなわち、Au−Sn合金にBiを含有させることによって、はんだ接合部において、特に接合部のうち濡れ広がる際の先端部分において、AuとBiとからなる融点の高い固体の金属間化合物が生成して余分な流れ出しをせき止めたり、はんだを半溶融状態にして実質的な流動性を下げて余分な流れ出しを抑制することができる。   In the case of the Au—Sn solder alloy having the above composition, the ratio of the solder that exhibits excellent shape maintenance at the time of solder joining and substantially contributes to the solder joint among the used solders (hereinafter also referred to as an effective solder volume ratio). A solder alloy that is high and that is less likely to generate voids can be obtained. That is, by adding Bi to the Au—Sn alloy, a solid intermetallic compound having a high melting point composed of Au and Bi is formed at the solder joint, particularly at the tip of the joint when wet and spread. Excessive flow out can be suppressed by damming up the excessive flow out or reducing the substantial fluidity by making the solder into a semi-molten state.

これにより、濡れ広がる前の溶融後のはんだ接合面積がほぼ維持され、よって実質的にはんだ接合に使用するはんだのほぼ100%をはんだ接合に寄与させることが可能になる。その結果、従来に比べて少ないはんだ量を用いても良好に接合を行うことができ、高い接合信頼性を得ることができる。MgおよびSbにも上記のBiの場合と同様の効果が期待できるため、本発明の第2の実施形態のはんだ合金にはこれらのうちの少なくとも一方が含有されている。なお、はんだの形状については特に制約はないが、枠状、シート状、リボン状およびボール状のうちのいずれかの場合に顕著な効果が得られる。次に、本発明のはんだ合金に含まれる各元素について詳しく説明する。   As a result, the solder joint area after melting before wetting and spreading is substantially maintained, so that substantially 100% of the solder used for solder joint can be substantially contributed to the solder joint. As a result, bonding can be performed satisfactorily even when using a smaller amount of solder than in the prior art, and high bonding reliability can be obtained. Since Mg and Sb can be expected to have the same effect as in the case of Bi described above, the solder alloy according to the second embodiment of the present invention contains at least one of them. In addition, although there is no restriction | limiting in particular about the shape of solder, A remarkable effect is acquired in the case of any of frame shape, sheet shape, ribbon shape, and ball shape. Next, each element contained in the solder alloy of the present invention will be described in detail.

<Au>
Auは本発明のはんだ合金の主成分を構成する必須の元素である。Auは非常に酸化されにくい性質を有しているため、高い信頼性が要求される電子部品類の接合用や封止用のはんだに求められる代表的な特性である濡れ性の点において最も優れている。よって、本発明の実施形態のはんだ合金においてはAuを主成分とすることで、水晶デバイスやSAWフィルターの接合用や封止用などの高信頼性を要求される用途に特に適したはんだを提供することができる。このAuを主成分とするはんだ合金に、優れた形状維持性や高い有効はんだ体積率を実現し、さらにボイドの発生を抑えるため、以下の元素を含有させる。
<Au>
Au is an essential element constituting the main component of the solder alloy of the present invention. Au is extremely resistant to oxidation, so it is the most excellent in terms of wettability, which is a typical characteristic required for solder for joining and sealing of electronic parts that require high reliability. ing. Therefore, in the solder alloy of the embodiment of the present invention, by providing Au as a main component, a solder that is particularly suitable for applications requiring high reliability, such as for joining or sealing crystal devices and SAW filters, is provided. can do. In order to achieve excellent shape maintainability and a high effective solder volume ratio in the solder alloy containing Au as a main component, and to suppress generation of voids, the following elements are included.

<Sn>
Snは本発明のはんだ合金においてAuとともに基本をなす必須の元素である。Au−Snはんだ合金は、共晶点であるAu−20質量%Sn付近の組成で通常使用され、これにより固相線温度が280℃で安定し、均一な濡れ性が得られる。本発明の実施形態のはんだ合金も、Au−20質量%Snを基本にすべく、Snの含有量を18.5質量%以上23.5%とし、後述するBi等の少量の添加元素および製造上、不可避的に含まれる元素を除き残部をAuとしている。かかる組成の下、適切な製造条件を選択すれば、好ましいラメラ状の金属組織が得られる。
<Sn>
Sn is an essential element that forms the basis together with Au in the solder alloy of the present invention. The Au—Sn solder alloy is usually used with a composition in the vicinity of Au-20 mass% Sn, which is the eutectic point, whereby the solidus temperature is stabilized at 280 ° C. and uniform wettability is obtained. The solder alloy according to the embodiment of the present invention is also based on Au-20 mass% Sn, so that the Sn content is 18.5 mass% or more and 23.5%, and a small amount of additive elements such as Bi, which will be described later, and production Above, except the elements inevitably included, the remainder is Au. If an appropriate production condition is selected under such a composition, a preferable lamellar metal structure can be obtained.

Snの含有率が18.5質量%未満の場合や23.5質量%を超えた場合は、亜共晶や過共晶になるため、初晶が発生してラメラ組織と混在し、製造条件を調整しても均一な濡れ性等を有するはんだ合金は得られない。従って、はんだ接合時に溶解してから凝固する時、局所的に融点が異なるため溶けが早い部分や遅い部分ができてしまう。このため、濡れ性にばらつきが出たり、個々に濡れ広がる部分や濡れ難くなる部分が存在することになる。例えば、リング状のAu−Snはんだ合金を溶融すると波状にAu−Snはんだが広がることがあるため、有効はんだ体積率を安定化するのが困難になり、はんだ接合した電子部品の品質にばらつきが生じることがある。なお、Snの含有量が19.0質量%以上22.8質量%以下であればより好ましい。   When the Sn content is less than 18.5% by mass or exceeds 23.5% by mass, it becomes hypoeutectic or hypereutectic, so primary crystals are generated and mixed with the lamellar structure. Even if this is adjusted, a solder alloy having uniform wettability cannot be obtained. Therefore, when solidifying after being melted at the time of soldering, the melting point is locally different, so that a part that melts quickly or a part that is slow is formed. For this reason, there are variations in wettability, and there are portions that spread individually and are difficult to wet. For example, when a ring-shaped Au—Sn solder alloy is melted, the Au—Sn solder may spread in a wave shape, which makes it difficult to stabilize the effective solder volume ratio, and the quality of soldered electronic components varies. May occur. In addition, it is more preferable if content of Sn is 19.0 mass% or more and 22.8 mass% or less.

<Bi>
Biは本発明のはんだ合金に含有される必須の元素であり、Biを含有させる目的は、優れた形状維持性や高い有効はんだ体積率を実現し、さらにボイドの発生を抑えるためである。Biを含有させることによって上記の効果が得られるメカニズムは次のとおりである。
<Bi>
Bi is an essential element contained in the solder alloy of the present invention, and the purpose of containing Bi is to achieve excellent shape maintainability and a high effective solder volume ratio, and to suppress the generation of voids. The mechanism by which the above effect can be obtained by including Bi is as follows.

すなわち、BiはAuとAuBi金属間化合物を生成し、この金属間化合物の融点は371℃である。一方、Au系はんだによって接合が行われる接合対象物の接合面は最上層がAuであることが多いが、このAuからなる最上層にBiを含有したAu系はんだ合金を接合させると融点の高いAuBiが生成し、半溶融状態となって実質的な流動性を下げ、且つ接合面に垂直な方向から見たはんだの端部(接合面上で溶けたはんだが乗っている面とはんだが乗っていない面の境界部に位置するはんだ)においてはAuが比較的多く存在するため特にAuBiが生成し易く、固体のAuBiが堰となってはんだの流れ出しを抑える。これにより、はんだの接合や封止の際、はんだ金属が溶融してから冷却して固化した後の接合対象物との接合部分の面積を、溶融前のはんだ合金が対向する面積とほぼ同程度に維持でき、またはんだ合金の形状もほとんど変化のないようにできる。 That is, Bi produces Au and Au 2 Bi intermetallic compound, and the melting point of this intermetallic compound is 371 ° C. On the other hand, the joining surface of the joining object to be joined by the Au-based solder is often the uppermost layer being Au. However, when an Au-based solder alloy containing Bi is joined to the uppermost layer made of Au, the melting point is high. Au 2 Bi is generated, becomes a semi-molten state, lowers the substantial fluidity, and is viewed from the direction perpendicular to the joint surface (the surface on which the molten solder rides on the joint surface and the solder) Since a relatively large amount of Au is present in the solder) located at the boundary portion of the surface where no surface is placed, Au 2 Bi is particularly easily generated, and solid Au 2 Bi acts as a weir to suppress the flow of solder. As a result, at the time of soldering or sealing, the area of the joint portion with the object to be joined after the solder metal is melted and then cooled and solidified is approximately the same as the area facing the solder alloy before melting. The shape of the alloy can be kept almost unchanged.

よって、使用したはんだ合金のほぼ全てをはんだ接合に有効に寄与させることができ、「有効はんだ体積率」をほぼ100%にすることができる。なお、接合対象物の接合面がAuでない場合であっても接合面の温度が低めであったり、レーザーではんだを溶融する場合には前述のようなメカニズムで同様の効果を得ることができる。   Therefore, almost all of the used solder alloy can be effectively contributed to the solder joint, and the “effective solder volume ratio” can be almost 100%. Even when the bonding surface of the object to be bonded is not Au, the same effect can be obtained by the mechanism as described above when the temperature of the bonding surface is low or the solder is melted by laser.

また、Biは前述したようにAuなどと合金化するため、ボイド発生の低減にも繋がる。すなわち、はんだとその接合対象物の接合面とが合金化しづらいと接合が不十分で未接合部分や空隙ができやすくなるが、当該接合面との合金化が進みやすいBiが含まれていることでボイドが発生しにくくなる。   In addition, since Bi is alloyed with Au or the like as described above, it also leads to reduction of void generation. That is, if it is difficult to alloy the solder and the joining surface of the object to be joined, the joining is insufficient, and unjoined portions and voids are likely to be formed, but Bi that is easily alloyed with the joining surface is included. This makes it difficult for voids to occur.

本発明のはんだ合金では、上記のBiの効果を得るためBiを0.01質量%以上0.5質量%未満の範囲内で含有している。Bi含有量が0.01質量%未満では少なすぎて含有させた効果が実質的に現れない。逆に、Bi含有量が0.5質量%以上では多すぎて液相線温度が高くなりすぎたり、金属間化合物が多くなりすぎたりして良好な接合ができなくなってしまう。Bi含有量は0.01質量%以上0.3質量%以下であると上記したBiの含有効果がより顕著に現れるので好ましい。   In the solder alloy of the present invention, Bi is contained in the range of 0.01 mass% or more and less than 0.5 mass% in order to obtain the above Bi effect. If the Bi content is less than 0.01% by mass, it is too small and the effect of inclusion is not substantially exhibited. On the other hand, if the Bi content is 0.5 mass% or more, the liquidus temperature becomes too high, or the intermetallic compound becomes too much, so that good bonding cannot be performed. The Bi content is preferably 0.01% by mass or more and 0.3% by mass or less because the above-described Bi content effect is more prominent.

<Mg>
Mgは本発明のはんだ合金において、MgおよびSbのうちの1種以上を含有するとの条件の下で含有される元素であり、Mgを含有させる目的も上記のBiと同様であって、優れた形状維持性と高い有効はんだ体積率の実現、およびボイド発生の抑制である。Mgを含有させることによってこれらの効果を得るメカニズムは次のとおりである。
<Mg>
Mg is an element that is contained in the solder alloy of the present invention under the condition that it contains one or more of Mg and Sb. The purpose of containing Mg is the same as Bi, and is excellent. Realization of shape maintainability, high effective solder volume ratio, and suppression of void generation. The mechanism for obtaining these effects by including Mg is as follows.

すなわち、MgはAuとAuMg、MgAu、AuMgなどの多くの金属間化合物を生成し、これらの金属間化合物の融点は400℃を超える。MgをAu系はんだに含有させた場合に生成されるこれら金属間化合物は当然Biの場合とは異なるが、はんだ接合時に優れた形状維持性や高い有効はんだ体積率を実現するメカニズムはBiと同様である。また、Mgを含有させることによりボイドの発生が低減する理由は、Mgが酸化されやすいことに起因する。すなわち、MgはAuはもちろんSnよりも酸化され易いためこれら主成分よりも先に酸化されて薄い酸化膜を生成し、これによって濡れ性が向上すると共にボイドの発生が低減する。 That is, Mg produces many intermetallic compounds such as Au and Au 4 Mg, MgAu, AuMg 2 and the melting point of these intermetallic compounds exceeds 400 ° C. These intermetallic compounds produced when Mg is contained in Au-based solder are naturally different from those of Bi, but the mechanism for achieving excellent shape retention and high effective solder volume ratio at the time of soldering is the same as Bi. It is. The reason why the generation of voids is reduced by containing Mg is that Mg is easily oxidized. That is, since Mg is more easily oxidized than Sn as well as Au, it is oxidized before these main components to form a thin oxide film, thereby improving wettability and reducing the generation of voids.

本発明のはんだ合金では、上記のMgの効果を得るためMgを0.01質量%以上2.00質量%以下の範囲内で含有している。Mgの含有量が0.01質量%未満では少なすぎて含有させた効果が実質的に現れない。逆に、2.00質量%を超えるとMg含有量が多すぎて金属間化合物が多くなりすぎたり、酸化膜が厚く生成したりして良好な接合ができなくなってしまう。   In the solder alloy of the present invention, Mg is contained in the range of 0.01% by mass or more and 2.00% by mass or less in order to obtain the above effect of Mg. If the content of Mg is less than 0.01% by mass, the effect of containing it is too small to appear substantially. On the other hand, if it exceeds 2.00% by mass, the Mg content is too high and the amount of intermetallic compounds becomes too large, or the oxide film is formed thick, and good bonding cannot be achieved.

<Sb>
Sbは本発明のはんだ合金において、前述したようにMgおよびSbのうちの1種以上を含有するとの条件の下で含有される元素であり、Sbを含有させる目的もBiやMgと同様であり、優れた形状維持性と高い有効はんだ体積率の実現、およびボイド発生の抑制である。Sbを含有させることによってこれらの効果を得るメカニズムは次のとおりである。
<Sb>
Sb is an element contained in the solder alloy of the present invention under the condition that it contains one or more of Mg and Sb as described above, and the purpose of containing Sb is the same as that of Bi and Mg. In other words, excellent shape retention and high effective solder volume ratio are achieved, and void generation is suppressed. The mechanism for obtaining these effects by incorporating Sb is as follows.

すなわち、SbはAuとAuSb金属間化合物を生成し、この金属間化合物の融点は460℃を超える。SbをAu系はんだに含有させた場合に生成されるこの金属間化合物は当然BiやMgとは異なるが、はんだ接合時に優れた形状維持性や高い有効はんだ体積率を実現するメカニズムは、BiやMgと同様である。また、SbはBiと同様のメカニズムでボイドの発生を低減する効果があり、接合強度の向上などにも寄与する。 That is, Sb produces Au and AuSb 2 intermetallic compound, and the melting point of this intermetallic compound exceeds 460 ° C. This intermetallic compound produced when Sb is contained in the Au-based solder is naturally different from Bi and Mg, but the mechanism for realizing excellent shape maintainability and a high effective solder volume ratio at the time of soldering is Bi or It is the same as Mg. In addition, Sb has an effect of reducing the generation of voids by the same mechanism as Bi, and contributes to improvement in bonding strength.

本発明のはんだ合金では、上記のSbの効果を得るためSbを0.01質量%以上5.00質量%以下の範囲内で含有している。Sb含有量が0.01質量%未満では少なすぎて含有させた効果が実質的に現れない。逆に、5.00質量%を超えるとSb含有量が多すぎて液相線温度が高くなりすぎたり、金属間化合物が多くなりすぎたりして良好な接合ができなくなってしまう。Sbの含有量は好ましくは1.00質量%を超え5.00質量%以下であり、さらに好ましくは1.20質量%を超え5.00質量%以下である。Sb含有量をこの範囲にすれば含有させた効果がより一層顕著に現れるので好ましい。   In the solder alloy of the present invention, Sb is contained in the range of 0.01 mass% or more and 5.00 mass% or less in order to obtain the effect of Sb described above. If the Sb content is less than 0.01% by mass, it is too small and the effect of inclusion is not substantially exhibited. On the other hand, if it exceeds 5.00% by mass, the Sb content is too high, the liquidus temperature becomes too high, or the intermetallic compound becomes too much, so that good bonding cannot be performed. The Sb content is preferably more than 1.00% by mass and not more than 5.00% by mass, more preferably more than 1.20% by mass and not more than 5.00% by mass. If the Sb content is within this range, the effect of inclusion is more prominent, which is preferable.

組成が異なる複数のAu−Snはんだ合金試料を作製して、それらの濡れ広がり性や接合信頼性について評価を行った。具体的には、まず原料としてそれぞれ純度99.999質量%以上のAu、Sn、Bi、MgおよびSbを準備した。大きな薄片やバルク状の原料については、溶解後の合金においてサンプリング場所による組成のバラツキがなく均一になるように留意しながら切断、粉砕等を行い、3mm以下の大きさに細かくした。次に、これら原料から所定量を秤量して、高周波溶解炉用グラファイト坩堝に入れた。   A plurality of Au—Sn solder alloy samples having different compositions were prepared, and their wet spreadability and bonding reliability were evaluated. Specifically, Au, Sn, Bi, Mg and Sb having a purity of 99.999% by mass or more were prepared as raw materials. Large flakes and bulk-shaped raw materials were cut and pulverized, etc. so as to be uniform with no variation in composition depending on the sampling location in the alloy after melting, and were reduced to a size of 3 mm or less. Next, a predetermined amount of these raw materials was weighed and put into a graphite crucible for a high-frequency melting furnace.

上記原料の入った坩堝を高周波溶解炉に入れ、酸化を抑制するために窒素を原料1kg当たり0.7L/分以上の流量で流した。この状態で溶解炉の電源を入れ、原料を加熱溶融させた。金属が溶融しはじめたら混合棒でよく攪拌し、局所的な組成のばらつきが起きないように均一に混ぜた。十分溶融したことを確認した後、高周波電源を切り、速やかにるつぼを取り出し、坩堝内の溶湯をはんだ母合金の鋳型に流し込んだ。鋳型には、圧延用として厚さ3mm×幅40mm×長さ150mmの板状の合金が得られるものを使用した。このようにして組成の異なる試料1〜24のはんだ母合金を作製した。これらの試料1〜24のはんだ母合金に対して、ICP発光分光分析器(SHIMADZU S−8100)を用いて組成分析を行った。得られた組成分析の結果を下記表1に示す。   The crucible containing the raw material was placed in a high-frequency melting furnace, and nitrogen was flowed at a flow rate of 0.7 L / min or more per kg of the raw material in order to suppress oxidation. In this state, the melting furnace was turned on to heat and melt the raw material. When the metal began to melt, it was stirred well with a mixing rod and mixed uniformly so as not to cause local compositional variations. After confirming sufficient melting, the high frequency power supply was turned off, the crucible was quickly taken out, and the molten metal in the crucible was poured into the mold of the solder mother alloy. As the mold, one that can obtain a plate-like alloy having a thickness of 3 mm, a width of 40 mm, and a length of 150 mm was used for rolling. In this way, solder mother alloys of Samples 1 to 24 having different compositions were produced. The solder mother alloys of Samples 1 to 24 were subjected to composition analysis using an ICP emission spectroscopic analyzer (SHIMADZU S-8100). The results of composition analysis obtained are shown in Table 1 below.

Figure 2017189793
Figure 2017189793

次に、温間圧延機を用いて各はんだ母合金をリボン状に加工した。その際、溶解鋳造工程に加えて、温間圧延工程でも金属組織の調整を行った。具体的には、準備した厚さ3mm×幅40mm×長さ150mmの板状母合金試料を温間圧延機を用いて、それぞれの試料を30.0±1.5μmの厚さになるように圧延した。得られたリボン状の試料に対して、プレス機でプレス用オイルを供給しながら打抜いて1.0mm×1.0mmの四角形状のプリフォーム材(打抜き品)を作製し、これら四角形状のプリフォーム材を用いて下記の濡れ広がり性の評価を行った。また、金型だけを変えて同様のプレス打抜きを行って外寸1.5mm×2.0mm、枠幅150μmの枠形状の打抜き品を作製し、これら枠形状のプリフォーム材を用いて下記の封止性および信頼性の評価を行った。   Next, each solder mother alloy was processed into a ribbon shape using a warm rolling mill. At that time, in addition to the melt casting process, the metal structure was also adjusted in the warm rolling process. Specifically, using a warm rolling mill, the prepared plate-shaped master alloy sample having a thickness of 3 mm, a width of 40 mm, and a length of 150 mm is set so that each sample has a thickness of 30.0 ± 1.5 μm. Rolled. The obtained ribbon-shaped sample is punched while supplying pressing oil with a press machine to produce a rectangular preform material (punched product) of 1.0 mm × 1.0 mm. Using the preform material, the following wet spreadability was evaluated. Also, by changing the mold only, the same press punching is performed to produce a punched article having an outer size of 1.5 mm × 2.0 mm and a frame width of 150 μm. Using these frame-shaped preforms, the following Sealability and reliability were evaluated.

<打抜き品(四角形状)の濡れ広がり性評価>
四角形状の各打抜き品の試料を基板に接合し、部分的な濡れ広がりの有無に基づいて濡れ広がり性を評価した。具体的には、濡れ性試験機(装置名:雰囲気制御式濡れ性試験機)を起動し、加熱するヒーター部分に2重のカバーをしてヒーター部の周囲4箇所から窒素ガスを12L/分の流量で流した。その後、ヒーター設定温度を融点より50℃高い温度にして加熱した。
<Evaluation of wettability of punched product (square shape)>
Each rectangular punched sample was bonded to a substrate, and the wet spreading property was evaluated based on the presence or absence of partial wet spreading. Specifically, a wettability tester (apparatus name: atmosphere control type wettability tester) is started, a double cover is applied to the heater part to be heated, and nitrogen gas is supplied from four locations around the heater part at 12 L / min. The flow rate was. Thereafter, the heater was set to a temperature higher than the melting point by 50 ° C. and heated.

ヒーター温度が設定値で安定した後、上面にAuめっき(膜厚:2.0μm)を有するCu基板(板厚:0.3mm)をヒーター部にセッティングして25秒加熱し、次に四角形状のはんだ試料を該Cu基板上に載せて25秒加熱した。はんだ試料の加熱が完了した後、Cu基板をヒーター部から取り上げ、その横の窒素雰囲気が保たれている場所に一旦置いて十分に冷却させてから大気中に取り出した。   After the heater temperature has stabilized at the set value, a Cu substrate (plate thickness: 0.3 mm) with Au plating (film thickness: 2.0 μm) on the upper surface is set in the heater part and heated for 25 seconds, and then in a square shape The solder sample was placed on the Cu substrate and heated for 25 seconds. After the heating of the solder sample was completed, the Cu substrate was picked up from the heater part, placed in a place where the nitrogen atmosphere next to the Cu substrate was kept, allowed to cool sufficiently, and then taken out into the atmosphere.

このようにして接合した接合体について、図1(a)に示すようにはんだ試料2が四角形状を保ったままAuめっきCu基板1に良好に接合していた場合を「○」、図1(b)に示すようにはんだ試料が接合前の四角形状を留めずにAuめっきCu基板1上で部分的に濡れ広がってはみ出し部2aが生じていた場合、または基板1がはんだをはじいて部分的もしくは全体的に接合できていなかった場合を「×」と評価した。   As for the joined body joined in this manner, as shown in FIG. 1 (a), the case where the solder sample 2 was satisfactorily joined to the Au-plated Cu substrate 1 while maintaining the square shape was indicated with “◯”, FIG. As shown in b), when the solder sample partially wets and spreads on the Au plated Cu substrate 1 without retaining the square shape before joining, the protruding portion 2a occurs, or the substrate 1 partially repels the solder. Or the case where it was not able to join as a whole was evaluated as "x".

<打抜き品(枠形状)の接合信頼性評価1(封止性)>
枠形状の各打抜き品の試料による封止性を確認するため、図2に示す形状の封止用容器3と封止用蓋4とを枠形状の各はんだ合金試料5で封止した。封止には簡易ダイボンダー(ウェストボンド社製、MODEL:7327C)を用い、窒素フロー中(8L/分)、融点より50℃高い温度で30秒保持し、その後、窒素フローされたサイドボックスで室温まで十分に冷却し、その後、封止体を大気中に取り出した。このようにして準備した各封止体を水中に2時間浸漬し、その後、水中から封止体を取り出し、解体してリーク状態を確認した。解体した封止体内部に水が入っていた場合はリークがあったと判断し、封止性を「×」と評価した。一方、このようなリークがなかった場合は「○」と評価した。
<Joint reliability evaluation 1 (sealing property) of punched product (frame shape)>
In order to confirm the sealing performance of each frame-shaped punched product sample, the sealing container 3 having the shape shown in FIG. 2 and the sealing lid 4 were sealed with each frame-shaped solder alloy sample 5. A simple die bonder (made by West Bond, MODEL: 7327C) is used for sealing, and is kept in a nitrogen flow (8 L / min) for 30 seconds at a temperature 50 ° C. higher than the melting point. Then, the sealing body was taken out into the atmosphere. Each sealing body prepared in this way was immersed in water for 2 hours, and then the sealing body was taken out from the water and disassembled to confirm a leak state. When water was contained in the disassembled sealed body, it was judged that there was a leak, and the sealing performance was evaluated as “x”. On the other hand, when there was no such leak, it was evaluated as “◯”.

<打抜き品(枠形状)の接合信頼性評価2(ヒートサイクル試験)>
枠形状の打抜き品に対して、はんだ接合の信頼性を評価するためヒートサイクル試験を行った。なお、この試験は上記接合信頼性評価1と同様にして得たはんだ合金で封止した封止体を用いて行った。まず、各封止体に対して、−40℃の冷却と+250℃の加熱とを1サイクルとして、これを所定のサイクル繰り返した。
<Joint Reliability Evaluation 2 (Heat Cycle Test) for Stamped Products (Frame Shape)>
A heat cycle test was performed on the frame-shaped punched product in order to evaluate the reliability of solder bonding. In addition, this test was done using the sealing body sealed with the solder alloy obtained similarly to the said joint reliability evaluation 1. FIG. First, for each sealing body, cooling at −40 ° C. and heating at + 250 ° C. were taken as one cycle, and this was repeated for a predetermined cycle.

その後、ヒートサイクル試験を行った各封止体を水中に2時間浸漬し、その後、水中から封止体を取り出し、解体してリーク状態を確認した。解体した封止体内部に水が入っていた場合はリークがあったと判断し、封止性を「×」と評価した。一方、このようなリークがなかった場合は「○」と評価した。これら接合信頼性評価1および2の結果を上記の濡れ広がり性評価とともに下記表2に示す。   Then, each sealing body which performed the heat cycle test was immersed in water for 2 hours, then, the sealing body was taken out from the water, disassembled, and the leak state was confirmed. When water was contained in the disassembled sealed body, it was judged that there was a leak, and the sealing performance was evaluated as “x”. On the other hand, when there was no such leak, it was evaluated as “◯”. The results of these joint reliability evaluations 1 and 2 are shown in Table 2 below together with the above-described wettability evaluation.

Figure 2017189793
Figure 2017189793

上記表2から分かるように、本発明の要件を満たしている試料1〜18のはんだ合金は、いずれも濡れ広がり性、接合信頼性評価1、および接合信頼性評価2の全ての評価項目において良好な特性を示している。即ち、濡れ広がり性の評価でははんだ試料がはみ出さず四角形状を保って接合でき、接合信頼性評価1ではリークが発生せず、さらに接合信頼性評価2では500回のヒートサイクルを繰り返してもリークは一切発生しなかった。   As can be seen from Table 2 above, all of the solder alloys of Samples 1 to 18 satisfying the requirements of the present invention are good in all the evaluation items of wet spreadability, bonding reliability evaluation 1, and bonding reliability evaluation 2. The characteristic is shown. That is, in the evaluation of wetting and spreading properties, the solder sample does not protrude and can be joined while maintaining a rectangular shape. In the joining reliability evaluation 1, no leakage occurs, and in the joining reliability evaluation 2, even after 500 heat cycles are repeated. No leaks occurred.

一方、本発明の比較例である試料19〜24のはんだ合金は、本発明の要件を満たしていないため、少なくともいずれかの評価項目で好ましくない結果となった。即ち、濡れ広がり性の評価でははんだ試料のはみ出し等が発生し、接合信頼性評価1では試料24を除いてリークが発生した。また接合信頼性評価2では試料24を除く全ての試料で300回までのヒートサイクルでリークが発生した。従来一般的に使用されているAu−20Sn質量%である試料24においては、はんだ組成が好ましい範囲に制御された本発明の要件を満たす試料1〜18に比べて濡れ広がり性および接合信頼性評価2において劣る結果となった。   On the other hand, since the solder alloys of Samples 19 to 24, which are comparative examples of the present invention, do not satisfy the requirements of the present invention, at least one of the evaluation items was not preferable. That is, in the evaluation of the wet spreading property, the solder sample protruded and the leakage occurred in the bonding reliability evaluation 1 except for the sample 24. Further, in the joint reliability evaluation 2, all samples except the sample 24 leaked up to 300 heat cycles. In the sample 24 which is Au-20Sn mass% generally used conventionally, the wet spreadability and the bonding reliability evaluation are compared with the samples 1 to 18 which satisfy the requirements of the present invention in which the solder composition is controlled within a preferable range. 2 was inferior.

1 AuめっきされたCu基板
2 四角形状のはんだ合金試料
2a はみ出し部
3 封止用容器
4 封止用蓋
5 枠形状のはんだ合金試料

DESCRIPTION OF SYMBOLS 1 Cu board | substrate plated with Au 2 Square shape solder alloy sample 2a Overhang | projection part 3 Sealing container 4 Sealing lid 5 Frame shape solder alloy sample

Claims (7)

Snを18.5質量%以上23.5質量%以下含有し、Biを0.01質量%以上0.5質量%未満含有し、残部が製造上不可避に含まれる元素を除きAuから構成されることを特徴とするAu−Sn系はんだ合金。   Sn is contained in an amount of 18.5% by mass or more and 23.5% by mass or less, Bi is contained in an amount of 0.01% by mass or more and less than 0.5% by mass, and the remainder is composed of Au except for elements inevitably included in production. An Au—Sn solder alloy characterized by the above. Snを18.5質量%以上23.5質量%以下含有し、Biを0.01質量%以上0.50質量%未満含有し、さらにMgおよびSbのうちの1種以上を、Mgの場合は0.01質量%以上2.00質量%以下、Sbの場合は1.00質量%を超え5.00質量%以下含有し、残部が製造上不可避に含まれる元素を除きAuから構成されることを特徴とするAu−Sn系はんだ合金。   In the case where Sn is contained in an amount of 18.5% by mass or more and 23.5% by mass or less, Bi is contained in an amount of 0.01% by mass or more and less than 0.50% by mass, and at least one of Mg and Sb is contained. 0.01 mass% or more and 2.00 mass% or less, and in the case of Sb, it contains more than 1.00 mass% and 5.00 mass% or less, and the balance is composed of Au except for elements inevitably included in production. An Au—Sn solder alloy characterized by 前記Biが0.01質量%以上0.3質量%以下含有していることを特徴とする、請求項1または2に記載のAu−Sn系はんだ合金。   The Au-Sn solder alloy according to claim 1 or 2, wherein the Bi is contained in an amount of 0.01 mass% or more and 0.3 mass% or less. 前記Snが19.0質量%以上22.8質量%以下含有することを特徴とする、請求項1〜3のいずれか1項に記載のAu−Sn系はんだ合金。   The Au-Sn based solder alloy according to any one of claims 1 to 3, wherein the Sn is contained in an amount of 19.0 mass% or more and 22.8 mass% or less. 前記はんだ合金の形状が枠状、シート状、リボン状、およびボール状のうちのいずれかであることを特徴とする、請求項1〜4のいずれか1項に記載のAu−Sn系はんだ合金。   5. The Au—Sn solder alloy according to claim 1, wherein the shape of the solder alloy is any one of a frame shape, a sheet shape, a ribbon shape, and a ball shape. . 請求項1〜5のいずれか1項に記載のAu−Sn系はんだ合金を用いて封止したことを特徴とする電子部品。   An electronic component, wherein the electronic component is sealed with the Au-Sn solder alloy according to any one of claims 1 to 5. 請求項6に記載の電子部品を搭載していることを特徴とする電子機器。

An electronic device comprising the electronic component according to claim 6.

JP2016079970A 2016-04-13 2016-04-13 Au-Sn-BASED SOLDER ALLOY Pending JP2017189793A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016079970A JP2017189793A (en) 2016-04-13 2016-04-13 Au-Sn-BASED SOLDER ALLOY

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016079970A JP2017189793A (en) 2016-04-13 2016-04-13 Au-Sn-BASED SOLDER ALLOY

Publications (1)

Publication Number Publication Date
JP2017189793A true JP2017189793A (en) 2017-10-19

Family

ID=60086402

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016079970A Pending JP2017189793A (en) 2016-04-13 2016-04-13 Au-Sn-BASED SOLDER ALLOY

Country Status (1)

Country Link
JP (1) JP2017189793A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020217833A1 (en) * 2019-04-22 2020-10-29 日鉄ケミカル&マテリアル株式会社 Junction structure, method for manufacturing junction structure, and solder ball

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020217833A1 (en) * 2019-04-22 2020-10-29 日鉄ケミカル&マテリアル株式会社 Junction structure, method for manufacturing junction structure, and solder ball

Similar Documents

Publication Publication Date Title
Hu et al. Effects of rare earth element Nd on the solderability and microstructure of Sn–Zn lead-free solder
JP6811798B2 (en) Molded solder and manufacturing method of molded solder
WO2015083661A1 (en) Solder material and joining structure
JP4560830B2 (en) Au-Sn alloy powder for solder paste
JP5187465B1 (en) High temperature lead-free solder alloy
JP2012200789A (en) Au-Sn ALLOY SOLDER
JP5461125B2 (en) Lead-free high-temperature bonding material
TW202126827A (en) High reliability lead-free solder alloys for harsh environment electronics applications
JP2016026884A (en) Bi-Sn-Al BASED SOLDER ALLOY FOR MEDIUM TO LOW TEMPERATURES AND SOLDER PASTE
JP5093373B2 (en) Pb-free solder paste
JP2017189793A (en) Au-Sn-BASED SOLDER ALLOY
CN115139009B (en) Preformed solder and preparation method thereof, and preparation method of welded joint
JP6413668B2 (en) Au-Sn-Ag solder alloy, solder material, electronic component sealed using this solder alloy or solder material, and electronic component mounting apparatus
JP2017196647A (en) Au-Sn-Ag-α-TYPE SOLDER ALLOY, ITS SOLDER MATERIAL, AND MOUNTING SUBSTRATE BONDED OR SEALED BY USING SOLDER MATERIAL
JP5765109B2 (en) Lead-free In-based solder alloy for CPU for server and its manufacturing method
JP2016016453A (en) Au-Ge-Sn-based solder alloy
JP2016026883A (en) Bi-Sn-Zn BASED SOLDER ALLOY FOR MEDIUM TO LOW TEMPERATURES AND SOLDER PASTE
US11618108B2 (en) Molded solder and molded solder production method
JP2017070959A (en) Au-Sb-Sn SOLDER PASTE
JP2016052662A (en) Au-Sn SOLDER ALLOY HAVING CONTROLLED METALLOGRAPHIC STRUCTURE
JP2012200788A (en) Au-Sn ALLOY SOLDER
JP2017035708A (en) Sb-Cu SOLDER ALLOY CONTAINING NO Pb
JP2016087641A (en) Pb-FREE Al-Cu-BASED SOLDER ALLOY
JP2016097444A (en) Pb-FREE Sb-In-BASED SOLDER ALLOY
JP2015139776A (en) Au-In TYPE SOLDER ALLOY