JP3926355B2 - Conductive material for connecting parts and method for manufacturing the same - Google Patents

Conductive material for connecting parts and method for manufacturing the same Download PDF

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JP3926355B2
JP3926355B2 JP2004264749A JP2004264749A JP3926355B2 JP 3926355 B2 JP3926355 B2 JP 3926355B2 JP 2004264749 A JP2004264749 A JP 2004264749A JP 2004264749 A JP2004264749 A JP 2004264749A JP 3926355 B2 JP3926355 B2 JP 3926355B2
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浩 坂本
幸男 杉下
理一 津野
基彦 鈴木
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株式会社神戸製鋼所
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本発明は、主として自動車・民生機器等の電気配線に使用されるコネクタ用端子やバスバー等の接続部品用導電材料に関し、特にオス端子とメス端子の挿抜に際しての摩擦や摩耗の低減及び使用に際しての電気的接続の信頼性の兼備が求められる嵌合型接続部品用導電材料に関するものである。   The present invention relates to conductive materials for connecting parts such as connector terminals and bus bars used mainly in electrical wiring of automobiles and consumer devices, and in particular, friction and wear during insertion and extraction of male terminals and female terminals and in use. The present invention relates to a conductive material for a fitting-type connecting part that is required to have a reliable electrical connection.

自動車・民生機器等の電気配線の接続に使用されるコネクタ用端子やバスバー等の接続部品用導電材料には、低レベルの信号電圧及び電流に対して高い電気的接続の信頼性が求められる重要な電気回路の場合などを除き、Snめっき(はんだめっき等のSn合金めっきを含む)施したCu又はCu合金が用いられている。SnめっきはAuめっきや他の表面処理に比べて低コストであることなどの理由により多用されているが、その中でも、近年の環境負荷物質規制への対応からPbを含まないSnめっき、特にウィスカの発生による回路短絡障害の報告例がほとんどないリフローSnめっきや溶融Snめっきが主流となってきている。   It is important that conductive materials for connecting parts such as connector terminals and bus bars used to connect electrical wiring of automobiles / consumer equipment require high electrical connection reliability for low-level signal voltages and currents. Except in the case of a simple electric circuit, Cu or Cu alloy subjected to Sn plating (including Sn alloy plating such as solder plating) is used. Sn plating is widely used for reasons such as low cost compared to Au plating and other surface treatments. Among them, Sn plating not containing Pb, particularly whisker, has been used in order to comply with recent environmentally hazardous substance regulations. Reflow Sn plating and molten Sn plating, which have almost no reports of short circuit faults due to the occurrence of the above, have become mainstream.

近年のエレクトロニクスの進展は目覚しく、例えば自動車においては安全性、環境性、快適性の追求から高度電装化が急速に進行している。これに伴い、回路数や重量などが増加して消費スペースや消費エネルギーなどが増加してしまうため、コネクタ用端子などの接続部品は、多極化、小型軽量化及びエンジンルーム内への搭載などを行っても、接続部品としての性能を満足し得るような、接続部品用導電材料が求められている。   In recent years, the progress of electronics has been remarkable. For example, in automobiles, advanced electronic components are rapidly progressing from the pursuit of safety, environment and comfort. As a result, the number of circuits, weight, etc. will increase, resulting in an increase in consumption space and energy consumption. Therefore, connection parts such as connector terminals will be multipolarized, reduced in size and weight, and installed in the engine room. However, there is a demand for a conductive material for connecting parts that can satisfy the performance as a connecting part.

接続部品用導電材料にSnめっきを施すおもな目的は、電気接点部や接合部において低い接触抵抗を得るとともに、表面に耐食性を付与し、接合をはんだ付けで行う接続部品用導電材料においてはそのはんだ付け性を得ることである。Snめっきは非常に軟質な導電性皮膜であり、その表面酸化皮膜が破壊されやすい。そのため、例えばオス端子とメス端子の組み合せからなる嵌合型端子において、インデントやリブなどの電気接点部がめっき同士の凝着によりガスタイト接触を形成しやすく、低い接触抵抗を得るのに好適である。また、使用に際して低い接触抵抗を維持するためには、Snめっきの厚さは厚い方が好ましく、また電気接点部同士を押しつける接圧力を大きくすることも重要である。   The main purpose of applying Sn plating to the conductive material for connecting parts is to obtain a low contact resistance at the electrical contact portion and the joint, and to provide corrosion resistance to the surface, and to solder the joint for the connecting component. It is to obtain the solderability. Sn plating is a very soft conductive film, and its surface oxide film is easily destroyed. Therefore, for example, in a fitting type terminal composed of a combination of a male terminal and a female terminal, electrical contact portions such as indents and ribs are easy to form a gastight contact by adhesion between platings, and are suitable for obtaining a low contact resistance. . Further, in order to maintain a low contact resistance during use, it is preferable that the thickness of the Sn plating is thick, and it is also important to increase the contact pressure for pressing the electrical contact portions.

しかしながら、Snめっきの厚さを厚くし、また電気接点部同士を押しつける接圧力を大きくすることは、Snめっき間の接触面積や凝着力を増加させるため、端子挿入の際にSnめっきの掘り起こしによる変形抵抗や凝着をせん断するせん断抵抗を増加させ、結果として挿入力を大きくさせてしまう。挿入力の大きい嵌合型接続部品は、組立作業の効率を低下させたり、嵌合ミスによる電気的接続の劣化の原因にもなる。このため、極数が増加しても、全体の挿入力が従来より大きくならないように、低挿入力の端子が要求されている。   However, increasing the thickness of the Sn plating and increasing the contact pressure that presses the electrical contact portions increases the contact area between the Sn plating and the adhesion force. This increases the shear resistance that shears deformation resistance and adhesion, resulting in increased insertion force. A fitting-type connecting component having a large insertion force can reduce the efficiency of assembly work or cause electrical connection deterioration due to a fitting error. For this reason, even if the number of poles increases, a terminal having a low insertion force is required so that the entire insertion force does not become larger than the conventional one.

下記特許文献1〜6には、Cu又はCu合金母材の表面に、必要に応じてNi下地めっき層を形成し、その上にCuめっき層とSnめっき層をこの順に形成した後、リフロー処理し、CuSn相を主体とするCu−Sn合金被覆層を形成した嵌合型端子材料が記載されている。これらの記載によれば、リフロー処理により形成されたこのCu−Sn合金層はNiめっきやCuめっきに比べて硬く、これが最表面に残留するSn層の下地層として存在することにより、端子の挿入力を低減することができる。また、表面のSn層により、低い接触抵抗を維持できる。 In the following Patent Documents 1 to 6, a Ni underplating layer is formed on the surface of the Cu or Cu alloy base material as necessary, and a Cu plating layer and an Sn plating layer are formed thereon in this order, followed by a reflow treatment. In addition, there is described a fitting type terminal material in which a Cu—Sn alloy coating layer mainly composed of a Cu 6 Sn 5 phase is formed. According to these descriptions, the Cu—Sn alloy layer formed by the reflow process is harder than Ni plating or Cu plating, and it exists as an underlayer of the Sn layer remaining on the outermost surface. The force can be reduced. Moreover, a low contact resistance can be maintained by the Sn layer on the surface.

特開2004−68026号公報JP 2004-68026 A 特開2003−151668号公報JP 2003-151668 A 特開2002−298963号公報JP 2002-298963 A 特開2002−226982号公報JP 2002-226882 A 特開平11−135226号公報JP-A-11-135226 特開平10−60666号公報Japanese Patent Laid-Open No. 10-60666

Sn層の下地にCu−Sn合金層を形成した端子の挿入力は、表面のSn層の厚さが薄くなると低下する。一方、Sn層の厚さが薄くなると、例えば自動車のエンジンルームのような150℃にも達する高温雰囲気に長時間保持したような場合、端子の接触抵抗が増加するという問題がある。また、Sn層の厚さが薄いと、耐食性及びはんだ付け性も低下する。このように、このタイプの端子において、低い挿入力、高温雰囲気に長時間保持後あるいは腐食環境下において低い接触抵抗の維持等、嵌合型端子に求められる特性をいまだ十分なかたちで得ることができず、さらなる改良が求められている。   The insertion force of the terminal in which the Cu—Sn alloy layer is formed on the base of the Sn layer decreases as the surface Sn layer becomes thinner. On the other hand, when the thickness of the Sn layer is reduced, there is a problem that the contact resistance of the terminal increases when the Sn layer is kept in a high temperature atmosphere as high as 150 ° C. for example for an automobile engine room for a long time. Further, when the Sn layer is thin, the corrosion resistance and solderability are also lowered. In this way, with this type of terminal, the characteristics required for a mating type terminal such as low insertion force, maintenance of low contact resistance in a high temperature atmosphere for a long time or in a corrosive environment can still be obtained sufficiently. However, further improvement is required.

従って、本発明は、Cu板条からなる母材表面にCu−Sn合金被覆層とSn被覆層を形成した接続部品用導電材料において、摩擦係数が低く(低い挿入力)、同時に電気的接続の信頼性(低い接触抵抗)を維持できる接続部品用導電材料を得ることを目的とする。   Therefore, the present invention provides a conductive material for connecting parts in which a Cu-Sn alloy coating layer and a Sn coating layer are formed on the surface of a base material made of a Cu plate, and has a low friction coefficient (low insertion force) and at the same time electrical connection. It is an object of the present invention to obtain a conductive material for connecting parts that can maintain reliability (low contact resistance).

本発明に係る接続部品用導電材料は、Cu板条からなる母材の表面に、Cu−Sn合金被覆層とSn被覆層がこの順に形成されており、前記Cu−Sn合金被覆層の材料表面露出面積率が3〜75%、平均の厚さが0.1〜3.0μm、かつCu含有量が20〜70at%であり、前記Sn又はSn合金被覆層の平均の厚さが0.2〜5.0μmであることを特徴とする。なお、この被覆層構成が形成された領域は、母材の片面又は両面全体に及んでいてもよいし、片面又は両面の一部のみを占めているのでもよい。
この接続部品用導電材料では、材料表面の少なくとも一方向において、前記Cu−Sn合金被覆層の平均の材料表面露出間隔が0.01〜0.5mmであることが望ましい。
In the conductive material for connecting parts according to the present invention, a Cu-Sn alloy coating layer and a Sn coating layer are formed in this order on the surface of a base material made of a Cu plate, and the material surface of the Cu-Sn alloy coating layer The exposed area ratio is 3 to 75%, the average thickness is 0.1 to 3.0 μm, the Cu content is 20 to 70 at%, and the average thickness of the Sn or Sn alloy coating layer is 0.2. It is -5.0 micrometers. In addition, the area | region in which this coating layer structure was formed may extend to the single side | surface or both surfaces of a preform | base_material, and may occupy only a part of single side | surface or both surfaces.
In this conductive material for connecting parts, it is desirable that an average material surface exposure interval of the Cu—Sn alloy coating layer is 0.01 to 0.5 mm in at least one direction of the material surface.

前記接続部品用導電材料において、前記母材表面と前記Cu−Sn合金被覆層の間にさらにCu被覆層を有していてもよい。
また、前記母材表面と前記Cu−Sn合金被覆層の間にさらにNi被覆層が形成されていてもよい。この場合、前記Ni被覆層とCu−Sn合金被覆層との間にさらにCu被覆層を有していてもよい。
なお、本発明において、Cu板条はCu合金板条を含む。また、Sn被覆層、Cu被覆層及びNi被覆層は、それぞれSn、Cu、Ni金属のほか、Sn合金、Cu合金及びNi合金を含む。
In the conductive material for connecting parts, a Cu coating layer may be further provided between the surface of the base material and the Cu-Sn alloy coating layer.
Further, a Ni coating layer may be further formed between the surface of the base material and the Cu—Sn alloy coating layer. In this case, a Cu coating layer may be further provided between the Ni coating layer and the Cu—Sn alloy coating layer.
In the present invention, the Cu strip includes a Cu alloy strip. In addition, the Sn coating layer, the Cu coating layer, and the Ni coating layer include Sn alloy, Cu alloy, and Ni alloy in addition to Sn, Cu, and Ni metal, respectively.

前記接続部品用導電材料は、Cu板条からなる母材の表面に、Cuめっき層とSnめっき層をこの順に形成した後、リフロー処理を行い、Cu−Sn合金被覆層と、Sn被覆層をこの順に形成することにより製造される。そして、本発明の製造方法は、母材表面につき、少なくとも一方向の算術平均粗さRaが0.15μm以上で、全ての方向の算術平均粗さRaが4.0μm以下の表面粗さとする点に特徴がある。リフロー処理により、Snめっき層が溶融流動して平滑化し、母材に形成された凹凸の凸の部分で、Cu−Sn合金被覆層の一部が材料の最表面に露出する。前記母材の表面粗さについては、前記一方向において算出された凹凸の平均間隔Sm(粗さ曲線が平均線と交差する交点から求めた山谷一周期の間隔の平均値)が0.01〜0.5mmであることが望ましい。
なお、前記母材表面において、前記表面粗さにして前記被覆層構成を形成する領域は、母材の片面又は両面全体に及んでいてもよいし、片面又は両面の一部のみを占めているのでもよい。
The conductive material for connecting parts is formed by forming a Cu plating layer and a Sn plating layer in this order on the surface of a base material made of a Cu plate, and then performing a reflow process to form a Cu-Sn alloy coating layer and a Sn coating layer. It is manufactured by forming in this order. In the production method of the present invention, the arithmetic average roughness Ra in at least one direction is 0.15 μm or more and the arithmetic average roughness Ra in all directions is 4.0 μm or less per surface of the base material. There is a feature. By the reflow process, the Sn plating layer is melted and flown and smoothed, and a part of the Cu—Sn alloy coating layer is exposed on the outermost surface of the material at the uneven portions formed on the base material. As for the surface roughness of the base material, the average interval Sm of unevenness calculated in the one direction (average value of intervals of one mountain valley period obtained from the intersection where the roughness curve intersects the average line) is 0.01 to It is desirable to be 0.5 mm.
Note that, in the base material surface, the region where the surface roughness is formed to form the coating layer structure may extend over one or both sides of the base material, or occupy only part of one side or both sides. It's okay.

前記Cu−Sn合金被覆層は、リフロー処理により、Cuめっき層とSnめっき層のCuとSnが相互拡散して形成されるが、その際にCuめっき層が全て消滅する場合と一部残留する場合の両方があり得る。Cuめっき層の厚さによっては、母材からもCuが供給される場合がある。母材表面に形成するCuめっき層の平均の厚さは1.5μm以下、Snめっき層の平均の厚さは0.3〜8.0μmの範囲が望ましい。Cuめっき層の平均の厚さは0.1μm以上が望ましい。
前記製造方法において、Cuめっき層を全く形成しない場合もあり得る。この場合、Cu−Sn合金被覆層のCuは、母材から供給される。
また、前記製造方法において、前記母材表面と前記Cuめっき層の間に、Niめっき層を形成してもよい。Niめっき層の平均の厚さは3μm以下とし、この場合のCuめっき層の平均の厚さは0.1〜1.5μmとするのが望ましい。
なお、本発明において、Cuめっき層、Snめっき層及びNiめっき層は、それぞれCu、Sn、Ni金属のほか、Cu合金、Sn合金及びNi合金を含む。
The Cu-Sn alloy coating layer is formed by inter-diffusion of Cu and Sn in the Cu plating layer and the Sn plating layer by reflow treatment, and in this case, the Cu plating layer is completely extinguished and partially remains. There can be both cases. Depending on the thickness of the Cu plating layer, Cu may also be supplied from the base material. The average thickness of the Cu plating layer formed on the surface of the base material is preferably 1.5 μm or less, and the average thickness of the Sn plating layer is preferably in the range of 0.3 to 8.0 μm. The average thickness of the Cu plating layer is preferably 0.1 μm or more.
In the manufacturing method, a Cu plating layer may not be formed at all. In this case, Cu of the Cu—Sn alloy coating layer is supplied from the base material.
In the manufacturing method, a Ni plating layer may be formed between the base material surface and the Cu plating layer. The average thickness of the Ni plating layer is 3 μm or less, and the average thickness of the Cu plating layer in this case is preferably 0.1 to 1.5 μm.
In addition, in this invention, Cu plating layer, Sn plating layer, and Ni plating layer contain Cu alloy, Sn alloy, and Ni alloy other than Cu, Sn, and Ni metal, respectively.

本発明に係る接続部品用導電材料は、特に嵌合型端子用として、摩擦係数を低く抑えることができるので、例えば自動車等において多極コネクタに使用した場合、オス、メス端子の嵌合時の挿入力が低く、組立作業を効率よく行うことができる。また高温雰囲気下で長時間保持されても、あるいは腐食環境下においても電気的信頼性(低接触抵抗)を維持でき、特に下地層としてNiめっきを施したものは、エンジンルーム等の、非常に高温で使用される箇所に配置された場合においても、一段と優れた電気的信頼性が保持できる。   Since the conductive material for connecting parts according to the present invention can keep the coefficient of friction low, particularly for fitting type terminals, for example, when used for multipolar connectors in automobiles, The insertion force is low and assembly work can be performed efficiently. In addition, it can maintain electrical reliability (low contact resistance) even in a high temperature atmosphere for a long time or in a corrosive environment. Even when it is arranged at a place where it is used at a high temperature, the electrical reliability can be further improved.

以下、本発明に係る接続部品用導電材料について、具体的に説明する。
(1)Cu−Sn合金被覆層について、そのCu含有量を20〜70at%とした理由について述べる。Cu含有量が20〜70at%のCu−Sn合金被覆層は、CuSn相を主体とする金属間化合物からなる。CuSn相はSn被覆層を形成するSn又はSn合金に比べて非常に硬く、それを材料の最表面に部分的に形成させると、端子挿抜の際にSn被覆層の掘り起こしによる変形抵抗や凝着をせん断するせん断抵抗を抑制でき、摩擦係数を非常に低くすることができる。一方、CuSn相はさらに硬いが、CuSn相に比べてCu含有量が多いため、これを材料表面に部分的に形成させた場合には、経時や腐食などによる材料表面のCuの酸化物量などが多くなり、接触抵抗を増加させ易く、電気的接続の信頼性を維持することが困難となる。また、CuSn相はCuSn相に比べて脆いために、成形加工性などが劣るという問題点がある。従って、Cu−Sn合金被覆層の構成成分を、Cu含有量が20〜70at%のCu−Sn合金に規定する。
このCu−Sn合金被覆層には、CuSn相が一部含まれていてもよく、母材及びSnめっき中の成分元素などが含まれていてもよい。しかし、Cu−Sn合金被覆層のCu含有量が20at%未満では凝着力が増して摩擦係数を低くすることが困難となり、一方Cu含有量が70at%を超えると電気的接続の信頼性を維持することが困難となり、成形加工性なども悪くなる。従って、Cu−Sn合金被覆層のCu含有量を20〜70at%に規定する。より望ましくは45〜65at%である。
Hereinafter, the conductive material for connecting parts according to the present invention will be specifically described.
(1) Regarding the Cu—Sn alloy coating layer, the reason for setting its Cu content to 20 to 70 at% will be described. The Cu—Sn alloy coating layer having a Cu content of 20 to 70 at% is made of an intermetallic compound mainly composed of a Cu 6 Sn 5 phase. The Cu 6 Sn 5 phase is very hard compared to Sn or Sn alloy forming the Sn coating layer, and when it is partially formed on the outermost surface of the material, deformation resistance due to digging of the Sn coating layer during terminal insertion / extraction And the shear resistance that shears the adhesion can be suppressed, and the friction coefficient can be made very low. On the other hand, the Cu 3 Sn phase is harder but has a higher Cu content than the Cu 6 Sn 5 phase. Therefore, when this is partially formed on the surface of the material, Cu on the surface of the material due to aging, corrosion, etc. As a result, the amount of oxide increases, and the contact resistance tends to increase, making it difficult to maintain the reliability of electrical connection. Further, since the Cu 3 Sn phase is more fragile than the Cu 6 Sn 5 phase, there is a problem that molding processability is inferior. Therefore, the constituent component of the Cu—Sn alloy coating layer is defined as a Cu—Sn alloy having a Cu content of 20 to 70 at%.
This Cu—Sn alloy coating layer may contain a part of the Cu 3 Sn phase, and may contain a base material, component elements during Sn plating, and the like. However, if the Cu content of the Cu—Sn alloy coating layer is less than 20 at%, it becomes difficult to reduce the friction coefficient by increasing the adhesion force, while if the Cu content exceeds 70 at%, the reliability of electrical connection is maintained. It becomes difficult to do, and moldability etc. worsen. Therefore, the Cu content of the Cu—Sn alloy coating layer is regulated to 20 to 70 at%. More desirably, it is 45 to 65 at%.

(2)Cu−Sn合金被覆層の平均の厚さを0.1〜3.0μmとした理由について述べる。なお本発明では、Cu−Sn合金被覆層の平均の厚さを、Cu−Sn合金被覆層に含有されるSnの面密度(単位:g/mm)をSnの密度(単位:g/mm)で除した値と定義する(下記実施例に記載したCu−Sn合金被覆層の平均の厚さ測定方法は、この定義に準拠するものである)。Cu−Sn合金被覆層の平均の厚さが0.1μm未満では、特に本発明のようにCu−Sn合金被覆層を材料表面に部分的に露出形成させる場合には、高温酸化などの熱拡散による材料表面のCuの酸化物量が多くなり、接触抵抗を増加させ易く、電気的接続の信頼性を維持することが困難となる。一方3.0μmを超える場合には、経済的に不利であり、生産性も悪く、硬い層が厚く形成されるために成形加工性なども悪くなる。従って、Cu−Sn合金被覆層の平均の厚さを0.1〜3.0μmに規定する。より望ましくは0.2〜1.0μmである。 (2) The reason why the average thickness of the Cu—Sn alloy coating layer is set to 0.1 to 3.0 μm will be described. In the present invention, the average thickness of the Cu—Sn alloy coating layer is defined as the surface density of Sn (unit: g / mm 2 ) contained in the Cu—Sn alloy coating layer as the Sn density (unit: g / mm). 3 ) defined as a value divided by (the method for measuring the average thickness of the Cu—Sn alloy coating layer described in the examples below is based on this definition). When the average thickness of the Cu—Sn alloy coating layer is less than 0.1 μm, particularly when the Cu—Sn alloy coating layer is partially exposed on the surface of the material as in the present invention, thermal diffusion such as high-temperature oxidation is performed. As a result, the amount of Cu oxide on the surface of the material increases, the contact resistance tends to increase, and it becomes difficult to maintain the reliability of electrical connection. On the other hand, when it exceeds 3.0 μm, it is economically disadvantageous, the productivity is poor, and the hard layer is formed thick, so that the moldability is also deteriorated. Therefore, the average thickness of the Cu—Sn alloy coating layer is specified to be 0.1 to 3.0 μm. More desirably, the thickness is 0.2 to 1.0 μm.

(3)Cu−Sn合金被覆層の材料表面露出面積率を3〜75%とした理由について述べる。なお本発明では、Cu−Sn合金被覆層の材料表面露出面積率を、材料の単位表面積あたりに露出するCu−Sn合金被覆層の表面積に100をかけた値として算出する。Cu−Sn合金被覆層の材料表面露出面積率が3%未満では、材料表面の凝着量が増すため低い摩擦係数を得ることが困難となる。しかしながら、3%未満の場合においても、掘り起こしによる変形抵抗を少なくするようにSn被覆層の平均の厚さなどを適切に制御(母材の凹凸に対応して厚みの薄い部分を設ける)すれば、低減効果は本発明より小さいものの低い摩擦係数を得ることが可能となる。一方75%を超える場合には、経時や腐食などによる材料表面のCuの酸化物量などが多くなり、接触抵抗を増加させ易く、電気的接続の信頼性を維持することが困難となる。従って、Cu−Sn合金被覆層の材料表面露出面積率を3〜75%に規定する。より望ましくは10〜50%である。 (3) The reason why the material surface exposed area ratio of the Cu—Sn alloy coating layer is set to 3 to 75% will be described. In the present invention, the material surface exposed area ratio of the Cu—Sn alloy coating layer is calculated as a value obtained by multiplying the surface area of the Cu—Sn alloy coating layer exposed per unit surface area of the material by 100. When the material surface exposed area ratio of the Cu—Sn alloy coating layer is less than 3%, it is difficult to obtain a low friction coefficient because the amount of adhesion on the material surface increases. However, even in the case of less than 3%, if the average thickness of the Sn coating layer is appropriately controlled so as to reduce the deformation resistance caused by digging (providing a thin portion corresponding to the unevenness of the base material) Although the reduction effect is smaller than that of the present invention, a low friction coefficient can be obtained. On the other hand, if it exceeds 75%, the amount of Cu oxide on the surface of the material due to aging or corrosion increases, and it is easy to increase the contact resistance and it becomes difficult to maintain the reliability of electrical connection. Therefore, the material surface exposed area ratio of the Cu—Sn alloy coating layer is specified to be 3 to 75%. More desirably, it is 10 to 50%.

(4)Sn被覆層の平均の厚さを0.2〜5.0μmとした理由について述べる。なお、本発明では、Sn被覆層の平均の厚さを、Sn被覆層に含有されるSnの面密度(単位:g/mm)をSnの密度(単位:g/mm)で割った値と定義する(下記実施例に記載したSn被覆層の平均の厚さ測定方法は、この定義に準拠するものである)。Sn被覆層の平均の厚さが0.2μm未満では、高温酸化などの熱拡散による材料表面のCuの酸化物量が多くなり、接触抵抗を増加させ易く、また耐食性も悪くなることから、電気的接続の信頼性を維持することが困難となる。一方5.0μmを超える場合には、経済的に不利であり、生産性も悪くなる。従って、Sn被覆層の平均の厚さを0.2〜5.0μmに規定する。より望ましくは0.5〜3.0μmである。
Sn被覆層がSn合金からなる場合、Sn合金のSn以外の構成成分としては、Pb、Bi、Zn、Ag、Cuなどが挙げられる。Pbについては50質量%未満、他の元素については10質量%未満が望ましい。
(4) The reason why the average thickness of the Sn coating layer is 0.2 to 5.0 μm will be described. In the present invention, the average thickness of the Sn coating layer was obtained by dividing the surface density (unit: g / mm 2 ) of Sn contained in the Sn coating layer by the density of Sn (unit: g / mm 3 ). (The method for measuring the average thickness of the Sn coating layer described in the following examples is based on this definition). If the average thickness of the Sn coating layer is less than 0.2 μm, the amount of Cu oxide on the surface of the material due to thermal diffusion such as high-temperature oxidation increases, and the contact resistance is likely to increase, and the corrosion resistance also deteriorates. It becomes difficult to maintain the reliability of the connection. On the other hand, if it exceeds 5.0 μm, it is economically disadvantageous and the productivity is also deteriorated. Therefore, the average thickness of the Sn coating layer is specified to be 0.2 to 5.0 μm. More desirably, the thickness is 0.5 to 3.0 μm.
In the case where the Sn coating layer is made of an Sn alloy, examples of constituents other than Sn of the Sn alloy include Pb, Bi, Zn, Ag, and Cu. Pb is preferably less than 50% by mass, and other elements are preferably less than 10% by mass.

(5)Cu−Sn合金被覆層の平均の材料表面露出間隔について、少なくとも一方向において0.01〜0.5mmが望ましいとした理由について述べる。なお本発明では、Cu−Sn合金被覆層の平均の材料表面露出間隔を、材料表面に描いた直線を横切るCu−Sn合金被覆層の平均の幅(前記直線に沿った長さ)とSn被覆層の平均の幅を足した値と定義する。Cu−Sn合金被覆層の平均の材料表面露出間隔が0.01mm未満では、高温酸化などの熱拡散による材料表面のCuの酸化物量が多くなり、接触抵抗を増加させ易く、電気的接続の信頼性を維持することが困難となる。一方、0.5mmを超える場合には、特に小型端子に用いた際に低い摩擦係数を得ることが困難となる場合が生じてくる。一般的に端子が小型になれば、インデントやリブなどの電気接点部(挿抜部)の接触面積が小さくなるため、挿抜の際にSn被覆層同士のみの接触確率が増加する。これにより凝着量が増すため、低い摩擦係数を得ることが困難となる。従って、Cu−Sn合金被覆層の平均の材料表面露出間隔を少なくとも一方向において0.01〜0.5mmに規定する。より望ましくは、Cu−Sn合金被覆層の平均の材料表面露出間隔を全ての方向において0.01〜0.5mmにする。これにより、挿抜の際のSn被覆層同士のみの接触確率が低下する。さらに望ましくは0.05〜0.3mmである。 (5) The reason why the average material surface exposure interval of the Cu—Sn alloy coating layer is preferably 0.01 to 0.5 mm in at least one direction will be described. In the present invention, the average material surface exposure interval of the Cu—Sn alloy coating layer is defined by the average width (length along the straight line) of the Cu—Sn alloy coating layer crossing the straight line drawn on the material surface and the Sn coating. It is defined as the value obtained by adding the average width of the layers. When the average material surface exposure interval of the Cu—Sn alloy coating layer is less than 0.01 mm, the amount of Cu oxide on the material surface due to thermal diffusion such as high-temperature oxidation increases, and it is easy to increase the contact resistance, and the reliability of electrical connection It becomes difficult to maintain the sex. On the other hand, when it exceeds 0.5 mm, it may be difficult to obtain a low coefficient of friction particularly when used for a small terminal. In general, when the terminal is reduced in size, the contact area of an electrical contact portion (insertion / extraction portion) such as an indent or a rib is reduced, so that the contact probability of only the Sn coating layers increases during insertion / extraction. This increases the amount of adhesion and makes it difficult to obtain a low coefficient of friction. Therefore, the average material surface exposure interval of the Cu—Sn alloy coating layer is defined as 0.01 to 0.5 mm in at least one direction. More desirably, the average material surface exposure interval of the Cu—Sn alloy coating layer is set to 0.01 to 0.5 mm in all directions. Thereby, the contact probability only of Sn coating layers in the case of insertion / extraction falls. More desirably, the thickness is 0.05 to 0.3 mm.

(6)黄銅や丹銅のようなZn含有Cu合金を母材として用いる場合などには、母材とCu−Sn合金被覆層の間にCu被覆層を有していてもよい。このCu被覆層はリフロー処理後にCuめっき層が残留したものである。Cu被覆層は、Znやその他の母材構成元素の材料表面への拡散を抑制するのに役立ち、はんだ付け性などが改善されることが広く知られている。Cu被覆層は厚くなりすぎると成型加工性などが劣化し、経済性も悪くなることから、Cu被覆層の厚さは3.0μm以下が好ましい。
Cu被覆層には、母材に含まれる成分元素等が少量混入していてもよい。また、Cu被覆層がCu合金からなる場合、Cn合金のCn以外の構成成分としてはSn、Zn等が挙げられる。Snの場合は50質量%未満、他の元素については5質量%未満が望ましい。
(6) When using a Zn-containing Cu alloy such as brass or brass as a base material, a Cu coating layer may be provided between the base material and the Cu—Sn alloy coating layer. This Cu coating layer is a layer in which the Cu plating layer remains after the reflow treatment. It is widely known that the Cu coating layer is useful for suppressing the diffusion of Zn and other base material constituent elements to the material surface, and improves the solderability. If the Cu coating layer becomes too thick, the moldability and the like deteriorate and the economic efficiency also deteriorates. Therefore, the thickness of the Cu coating layer is preferably 3.0 μm or less.
A small amount of component elements contained in the base material may be mixed in the Cu coating layer. Moreover, when Cu covering layer consists of Cu alloy, Sn, Zn, etc. are mentioned as structural components other than Cn of Cn alloy. In the case of Sn, less than 50% by mass, and for other elements, less than 5% by mass is desirable.

(7)また、母材とCu−Sn合金被覆層の間(Cu被覆層がない場合)、又は母材とCu被覆層の間に、Ni被覆層が形成されていてもよい。Ni被覆層はCuや母材構成元素の材料表面への拡散を抑制して、高温長時間使用後も接触抵抗の上昇を抑制するとともに、Cu−Sn合金被覆層の成長を抑制してSn被覆層の消耗を防止し、また亜硫酸ガス耐食性が向上することが知られている。また、Ni被覆層自身の材料表面への拡散はCu−Sn合金被覆層やCu被覆層により抑制される。このことから、Ni被覆層を形成した接続部品用材料は、耐熱性が求められる接続部品に特に適する。Ni被覆層は厚くなりすぎると成型加工性などが劣化し、経済性も悪くなることから、Ni被覆層の厚さは3.0μm以下が好ましい。
Ni被覆層には、母材に含まれる成分元素等が少量混入していてもよい。また、Ni被覆層がNi合金からなる場合、Ni合金のNi以外の構成成分としては、Cu、P、Coなどが挙げられる。Cuについては40質量%以下、P、Coについては10質量%以下が望ましい。
(7) Moreover, the Ni coating layer may be formed between the base material and the Cu—Sn alloy coating layer (when there is no Cu coating layer) or between the base material and the Cu coating layer. The Ni coating layer suppresses the diffusion of Cu and matrix constituent elements to the surface of the material, suppresses the increase in contact resistance even after use at high temperature for a long time, and suppresses the growth of the Cu—Sn alloy coating layer to provide the Sn coating. It is known that layer consumption is prevented and sulfurous acid corrosion resistance is improved. Further, the diffusion of the Ni coating layer itself onto the material surface is suppressed by the Cu—Sn alloy coating layer or the Cu coating layer. For this reason, the connecting component material on which the Ni coating layer is formed is particularly suitable for connecting components that require heat resistance. If the Ni coating layer becomes too thick, the moldability and the like deteriorate and the economic efficiency also deteriorates. Therefore, the thickness of the Ni coating layer is preferably 3.0 μm or less.
The Ni coating layer may contain a small amount of component elements contained in the base material. Moreover, when Ni coating layer consists of Ni alloy, Cu, P, Co etc. are mentioned as structural components other than Ni of Ni alloy. For Cu, 40% by mass or less, and for P and Co, 10% by mass or less are desirable.

(8)材料表面の凹凸は表面光沢を低下させ、摩擦係数や接触抵抗に悪影響を及ぼす場合があるため、なるべく平滑なほうが望ましい。母材表面の凹凸が激しい材料の表面を平滑化する方法には、被覆層を形成させた後に研削、研磨などを行う機械的方法や、Sn被覆層をリフロー処理する方法が挙げられるが、経済性や生産性を考慮すると、Sn被覆層をリフロー処理する方法が望ましい。これらの方法は、Cu−Sn合金被覆層を最表面に露出させる方法でもある。
凹凸の激しい母材表面に直接に、あるいはNiめっき層やCuめっき層を介してSnめっき層を施した場合、めっきの均一電着性が良好であれば、Snめっき層表面は、母材の表面形態を反映して凹凸の激しい表面が得られてしまう。これに最適なリフロー処理を施すと、溶融した表面凸部のSnが表面凹部に流動する作用により、材料表面を平滑化できる。また加熱溶融処理を施すことにより、耐ウィスカ性も向上する。なお、Cuめっき層と溶融したSnめっき層の間に形成されるCu−Sn拡散合金層は、通常、母材の表面形態を反映して成長する。
(8) Since unevenness on the surface of the material lowers the surface gloss and may adversely affect the coefficient of friction and contact resistance, it is desirable that the surface is as smooth as possible. Examples of the method of smoothing the surface of a material having a rough surface of the base material include a mechanical method of grinding and polishing after forming a coating layer, and a method of reflowing the Sn coating layer. Considering the properties and productivity, a method of reflowing the Sn coating layer is desirable. These methods are also methods for exposing the Cu—Sn alloy coating layer to the outermost surface.
When the Sn plating layer is applied directly on the surface of the base material with severe irregularities or through the Ni plating layer or the Cu plating layer, if the uniform electrodeposition of plating is good, the Sn plating layer surface is Reflecting the surface form, a highly uneven surface is obtained. When an optimum reflow process is performed for this, the surface of the material can be smoothed by the action of the molten Sn of the surface convex portion flowing into the surface concave portion. Moreover, whisker resistance is also improved by performing the heat melting treatment. The Cu—Sn diffusion alloy layer formed between the Cu plating layer and the molten Sn plating layer usually grows reflecting the surface form of the base material.

続いて、本発明に係る接続部品用導電材料の製造方法について、具体的に説明する。
(1)本発明の接続部品用導電材料は、Cu−Sn合金被覆層の材料表面露出面積率が3〜75%でありながら、Sn被覆層が平均の厚さ0.2〜5.0μmで存在することを主たる特徴とする。なお、従来の接続部品用導電材料においては、Cu−Sn合金被覆層が表面に露出する状態であれば、Sn被覆層は完全に又はほとんど消滅した状態になっていた。
本発明の構造の接続部品用導電材料を得るには、通常の表面粗さの小さい母材を用いるのであれば、Cu−Sn拡散合金層の成長速度を部分的に制御する方法(例えばレーザーによるミクロ的なスポット加熱により、Cu−Sn拡散合金層が表面まで成長した箇所を材料表面に分散形成する)がまず考えられる。しかしながら、この方法での製造は非常に困難であり、経済的にも不利である。
Next, the method for producing the conductive material for connection parts according to the present invention will be specifically described.
(1) The conductive material for connecting parts of the present invention has an Sn coating layer with an average thickness of 0.2 to 5.0 μm while the material surface exposed area ratio of the Cu—Sn alloy coating layer is 3 to 75%. Its main feature is existence. In the conventional conductive material for connecting parts, if the Cu—Sn alloy coating layer is exposed on the surface, the Sn coating layer is completely or almost extinguished.
In order to obtain a conductive material for connecting parts having the structure of the present invention, a method of partially controlling the growth rate of the Cu—Sn diffusion alloy layer (for example, using a laser) is used if a base material having a small surface roughness is used. First, it is conceivable that the portion where the Cu—Sn diffusion alloy layer has grown to the surface is dispersedly formed on the material surface by microscopic spot heating. However, production by this method is very difficult and economically disadvantageous.

これに対し、本発明の方法は、母材の表面を粗化処理したうえで、該母材表面に直接に、あるいはNiめっき層やCuめっき層を介してSnめっき層を施し、続いてリフロー処理する方法であり、経済性や生産性に優れるため、本発明に係る接続部品用導電材料を得るのに最適な方法と考えられる。母材の表面を粗化処理する方法としては、イオンエッチング等の物理的方法、エッチングや電解研磨等の化学的方法、圧延(研磨やショットブラスト等により粗面化したロールを使用)、研磨、ショットブラスト等の機械的方法が挙げられる。この中で、生産性、経済性および母材表面形態の再現性に優れる方法としては、圧延や研磨が望ましい。
なお、Niめっき層、Cuめっき層及びSnめっき層が、それぞれNi合金、Cu合金及びSn合金からなる場合、先にNi被覆層、Cu被覆層及びSn被覆層に関して説明した各合金を用いることができる。
On the other hand, in the method of the present invention, after roughening the surface of the base material, an Sn plating layer is applied directly to the surface of the base material or via a Ni plating layer or a Cu plating layer, followed by reflow. Since this is a method for processing and is excellent in economic efficiency and productivity, it is considered to be an optimum method for obtaining the conductive material for connecting parts according to the present invention. As a method of roughening the surface of the base material, a physical method such as ion etching, a chemical method such as etching or electrolytic polishing, rolling (using a roll roughened by polishing or shot blasting), polishing, A mechanical method such as shot blasting can be used. Among these methods, rolling and polishing are desirable as methods that are excellent in productivity, economy, and reproducibility of the base material surface form.
In addition, when the Ni plating layer, the Cu plating layer, and the Sn plating layer are respectively made of a Ni alloy, a Cu alloy, and a Sn alloy, it is possible to use the respective alloys described above regarding the Ni coating layer, the Cu coating layer, and the Sn coating layer. it can.

(2)ここで、母材の表面粗さについて、少なくとも一方向の算術平均粗さRaが0.15μm以上、かつ全ての方向の算術平均粗さRaが4.0μm以下とした理由について述べる。全ての方向において算術平均粗さRaが0.15μm未満の場合、本発明の接続部品用導電材料の製造が非常に困難となる。具体的にいえば、Cu−Sn合金被覆層の材料表面露出面積率を3〜75%としながら、Sn被覆層の平均の厚さを0.2〜5.0μmとすることが非常に困難となる。一方、いずれかの方向において算術平均粗さRaが4.0μmを超える場合、溶融Sn又はSn合金の流動作用による材料表面の平滑化が困難となる。従って、母材の表面粗さは、少なくとも一方向の算術平均粗さRaが0.15μm以上かつ全ての方向の算術平均粗さRaが4.0μm以下と規定する。この表面粗さとしたことにより、溶融Sn又はSn合金の流動作用(材料表面の平滑化)に伴い、リフロー処理で成長したCu−Sn合金被覆層の一部が材料の最表面に露出する。
母材の表面粗さについては、より望ましくは、少なくとも一方向の算術平均粗さRaが0.3μm以上かつ全ての方向の算術平均粗さRaが3.0μm以下である。さらに望ましくは、前記一方向において算出された凹凸の平均間隔Smが0.01〜0.5mmである。これにより、材料表面に露出するCu−Sn合金被覆層の露出形態を制御することが可能となる。
(2) Here, regarding the surface roughness of the base material, the reason why the arithmetic average roughness Ra in at least one direction is 0.15 μm or more and the arithmetic average roughness Ra in all directions is 4.0 μm or less will be described. When the arithmetic average roughness Ra is less than 0.15 μm in all directions, it is very difficult to manufacture the conductive material for connecting parts of the present invention. Specifically, it is very difficult to set the average thickness of the Sn coating layer to 0.2 to 5.0 μm while setting the material surface exposed area ratio of the Cu—Sn alloy coating layer to 3 to 75%. Become. On the other hand, when the arithmetic average roughness Ra exceeds 4.0 μm in any direction, it becomes difficult to smooth the surface of the material due to the flow action of molten Sn or Sn alloy. Accordingly, the surface roughness of the base material is defined such that the arithmetic average roughness Ra in at least one direction is 0.15 μm or more and the arithmetic average roughness Ra in all directions is 4.0 μm or less. Due to the surface roughness, a part of the Cu—Sn alloy coating layer grown by the reflow process is exposed on the outermost surface of the material due to the flowing action of the molten Sn or Sn alloy (smoothing of the material surface).
Regarding the surface roughness of the base material, it is more desirable that the arithmetic average roughness Ra in at least one direction is 0.3 μm or more and the arithmetic average roughness Ra in all directions is 3.0 μm or less. More preferably, the average interval Sm between the irregularities calculated in the one direction is 0.01 to 0.5 mm. This makes it possible to control the exposed form of the Cu—Sn alloy coating layer exposed on the material surface.

(3)またリフロー処理を行う場合のリフロー条件は、Snめっき層の溶融温度〜600℃×3〜30秒間とする。Sn金属の場合、加熱温度が230℃未満では溶融せず、低すぎないCu含有量のCu−Sn合金被覆層を得るには、望ましくは240℃以上であり、600℃を越えると母材が軟化し、歪みが発生するとともに、高すぎるCu含有量のCu−Sn合金被覆層が形成され、接触抵抗を低く維持することができない。加熱時間が3秒未満では熱伝達が不均一となり、十分な厚みのCu−Sn合金被覆層を形成できず、30秒を越えると表面のSn層の酸化が進行するため、接触抵抗が増加する。
このリフロー処理を行うことにより、Cu−Sn合金被覆層が形成され、溶融Sn又はSn合金が流動して材料表面が平滑化され、Cu−Sn合金被覆層の一部が材料の最表面に露出する。また、めっき粒子が大きくなり、めっき応力が低下し、ウイスカが発生しなくなる。いずれにしても、Cu−Sn合金層を均一に成長させるためには、熱処理はSn又はSn合金の溶融する温度で、300℃以下のできるだけ少ない熱量で行うことが望ましい。
(3) Moreover, the reflow conditions in the case of performing the reflow treatment are the melting temperature of the Sn plating layer to 600 ° C. × 3 to 30 seconds. In the case of Sn metal, when the heating temperature is less than 230 ° C., it does not melt, and in order to obtain a Cu-Sn alloy coating layer with a Cu content that is not too low, it is desirably 240 ° C. or higher. Softening and distortion occur, and a Cu-Sn alloy coating layer with an excessively high Cu content is formed, and the contact resistance cannot be kept low. If the heating time is less than 3 seconds, the heat transfer becomes non-uniform, and a Cu—Sn alloy coating layer having a sufficient thickness cannot be formed. If the heating time exceeds 30 seconds, oxidation of the Sn layer on the surface proceeds, and the contact resistance increases. .
By performing this reflow treatment, a Cu—Sn alloy coating layer is formed, the molten Sn or Sn alloy flows to smooth the material surface, and a part of the Cu—Sn alloy coating layer is exposed on the outermost surface of the material. To do. Further, the plating particles become large, the plating stress is lowered, and whiskers are not generated. In any case, in order to uniformly grow the Cu—Sn alloy layer, it is desirable to perform the heat treatment at the temperature at which Sn or the Sn alloy melts and with as little heat as possible at 300 ° C. or less.

(4)なお、これまで、本発明に係る導電材料の製造方法に関し、母材に直接、あるいはNiめっき層やCuめっき層を介してSnめっき層をこの順に形成した後、リフロー処理してCu−Sn合金層を形成し、更に材料表面を平滑化する方法を説明したが、本発明に係る接続部品用導電材料の被覆層構成は、母材に直接、あるいはNiめっき層を介してCu−Sn合金めっき層を形成し、その上にSn合金めっき層を形成し、リフロー処理することでも得ることができる。後者の方法も本発明に含まれる。 (4) Until now, regarding the method for producing a conductive material according to the present invention, a Sn plating layer is formed in this order directly on a base material or via a Ni plating layer or a Cu plating layer, and then subjected to reflow treatment to form Cu. Although the method of forming a Sn alloy layer and further smoothing the surface of the material has been described, the coating layer structure of the conductive material for connecting parts according to the present invention can be formed directly on the base material or via a Ni plating layer. It can also be obtained by forming a Sn alloy plating layer, forming a Sn alloy plating layer thereon, and performing a reflow treatment. The latter method is also included in the present invention.

以上述べた本発明に係る接続部品用導電材料の断面構造(リフロー後)を、図1に模式的に示す。この図では、母材Aの一方の表面(図1において上側の表面)が粗面化され、他方の表面が従来材と同じく平滑である。粗面化した前記一方の表面では、表面の凹凸に沿って、数μm程度の径の粒子からなるCu−Sn合金被覆層Yが形成され、Sn被覆層Xが溶融流動して平滑化しており、それに伴い、Cu−Sn合金被覆層Yが一部材料表面に露出している。平滑な前記他方の表面では、従来材と同じく、Cu−Sn合金被覆層Yの全面をSn被覆層Xが覆っている。   The cross-sectional structure (after reflow) of the conductive material for connecting parts according to the present invention described above is schematically shown in FIG. In this figure, one surface of the base material A (upper surface in FIG. 1) is roughened, and the other surface is smooth as in the conventional material. On the roughened one surface, a Cu—Sn alloy coating layer Y made of particles having a diameter of about several μm is formed along the unevenness of the surface, and the Sn coating layer X is melted and flown to be smoothed. Accordingly, the Cu—Sn alloy coating layer Y is partially exposed on the material surface. On the other smooth surface, the Sn coating layer X covers the entire surface of the Cu—Sn alloy coating layer Y as in the conventional material.

このように本発明の接続部品用導電材料は、電気的接続の信頼性の維持に必要なSn被覆層を厚く形成させても、電気的接続の信頼性が比較的良好で、かつ端子挿抜の際の挿抜力を低下させるのに効果的なCu−Sn合金被覆層を、材料表面に適正な条件で露出させているため、摩擦係数が低く、電気的接続の信頼性(低い接触抵抗)を維持することができる。
また、この接続部品用導電材料は、少なくとも端子が挿抜される部分の被覆層構成について、Cu−Sn合金被覆層とSn被覆層がこの順に形成され、Cu−Sn合金被覆層の材料表面露出面積率が3〜75%、平均の厚さが0.1〜3.0μm、かつCu含有量が20〜70at%、及びSn被覆層の平均の厚さが0.2〜5.0μmとなっていればよく、端子が挿抜されない部分(例えば、ワイヤやプリント基板との接合部)の被覆層構成は前記規定を満たしていなくてもよい。しかし、この接続部品用導電材料を端子が挿抜されない部分に適用すれば、電気的接続の信頼性を更に高くすることが可能となる。
As described above, the conductive material for connecting parts of the present invention has relatively good electrical connection reliability even when the Sn coating layer necessary for maintaining the reliability of the electrical connection is formed thick, and the insertion / extraction of the terminals. The Cu-Sn alloy coating layer, which is effective in reducing the insertion / extraction force at the time, is exposed to the material surface under appropriate conditions, so that the friction coefficient is low and the reliability of electrical connection (low contact resistance) is achieved. Can be maintained.
In addition, this conductive material for connecting parts has a Cu—Sn alloy coating layer and an Sn coating layer formed in this order for at least a portion of the coating layer configuration in which the terminal is inserted and removed, and the material surface exposed area of the Cu—Sn alloy coating layer The rate is 3 to 75%, the average thickness is 0.1 to 3.0 μm, the Cu content is 20 to 70 at%, and the average thickness of the Sn coating layer is 0.2 to 5.0 μm. The covering layer configuration of the portion where the terminal is not inserted / extracted (for example, a joint portion with a wire or a printed board) may not satisfy the above-mentioned definition. However, if this conductive material for connecting parts is applied to a portion where the terminal is not inserted / extracted, the reliability of electrical connection can be further increased.

以下の実施例により、要点を絞り、更に具体的に説明するが、本発明はこれらの実施例に限定されるものではない。   The following examples will focus on the essential points and will be described more specifically, but the present invention is not limited to these examples.

[Cu合金母材の作製]
表1に、使用したCu合金(No.1、2)の化学成分を示す。本実施例においては、これらのCu合金に機械的な方法(圧延又は研磨)で表面粗化処理を行い、厚さ0.25mmで、所定の表面粗さを有するCu合金母材に仕上げた。なお、表面粗さは下記要領で測定した。
[Cu合金母材の表面粗さ測定方法]
接触式表面粗さ計(株式会社東京精密;サーフコム1400)を用いて、JIS B0601−1994に基づいて測定した。表面粗さ測定条件は、カットオフ値を0.8mm、基準長さを0.8mm、評価長さを4.0mm、測定速度を0.3mm/s、及び触針先端半径を5μmRとした。なお、表面粗さ測定方向は、表面粗化処理の際に行った圧延又は研磨方向に直角な方向(表面粗さが最も大きく出る方向)とした。
[Preparation of Cu alloy base material]
Table 1 shows chemical components of the used Cu alloys (Nos. 1 and 2). In this example, these Cu alloys were subjected to a surface roughening treatment by a mechanical method (rolling or polishing) to finish a Cu alloy base material having a predetermined surface roughness with a thickness of 0.25 mm. The surface roughness was measured as follows.
[Method for measuring surface roughness of Cu alloy base material]
It measured based on JISB0601-1994 using the contact-type surface roughness meter (Tokyo Seimitsu; Surfcom 1400). The surface roughness measurement conditions were a cutoff value of 0.8 mm, a reference length of 0.8 mm, an evaluation length of 4.0 mm, a measurement speed of 0.3 mm / s, and a stylus tip radius of 5 μmR. The surface roughness measurement direction was a direction perpendicular to the rolling or polishing direction performed during the surface roughening treatment (the direction in which the surface roughness is maximized).

各々の表面粗化処理を行った(No.7,8は行わず)Cu合金母材に対して、Cu合金No.1には厚さが0.15μm、Cu合金No.2には厚さが0.65μmのCuめっきをそれぞれ施し、さらに厚さが1.0μmのSnめっきを施した後、280℃で10秒間のリフロー処理を行うことにより供試材(No.1〜10)を得た。その製造条件を表2に示す。なお、母材の表面粗さパラメータのうち、凹凸の平均間隔Smに関しては、全て前記望ましい範囲内(0.01〜0.5mm)にあった。また、表2に記載されたCuめっき及びSnめっきの平均の厚さは、下記要領で測定した。   Each of the surface roughening treatments was performed (Nos. 7 and 8 were not performed). No. 1 has a thickness of 0.15 μm, Cu alloy No. 1 No. 1 was subjected to a reflow treatment at 280 ° C. for 10 seconds after a Cu plating with a thickness of 0.65 μm was applied to each No. 2 and a Sn plating with a thickness of 1.0 μm was further applied. To 10). The production conditions are shown in Table 2. In addition, among the surface roughness parameters of the base material, the average interval Sm of the unevenness was all within the desired range (0.01 to 0.5 mm). Moreover, the average thickness of Cu plating and Sn plating described in Table 2 was measured as follows.

[Cuめっきの平均の厚さ測定方法]
ミクロトーム法にて加工した母材の断面をSEM(走査型電子顕微鏡)を用いて10,000倍の倍率で観察し、画像解析処理により平均の厚さを算出した。
[Snめっきの平均の厚さ測定方法]
蛍光X線膜厚計(セイコーインスツルメンツ株式会社;SFT3200)を用いて平均の厚さを算出した。測定条件は、検量線にSn/母材の単層検量線を用い、コリメータ径をφ0.5mmとした。
[Measuring method of average thickness of Cu plating]
The cross section of the base material processed by the microtome method was observed at a magnification of 10,000 using a SEM (scanning electron microscope), and the average thickness was calculated by image analysis processing.
[Method for measuring average thickness of Sn plating]
The average thickness was calculated using a fluorescent X-ray film thickness meter (Seiko Instruments Inc .; SFT3200). The measurement conditions were a single-layer Sn / base metal calibration curve as the calibration curve, and a collimator diameter of 0.5 mm.

続いて、得られた供試材の被覆層構成を、表3に示す。Cu−Sn合金被覆層の平均の厚さ、Cu含有量、露出面積率、及びSn被覆層の平均の厚さについては、下記要領で測定した。なお、Cu−Sn合金被覆層が最表面に露出したものは、その表面露出間隔が全て前記望ましい範囲内(0.01〜0.5mm)にあった。
[Cu−Sn合金被覆層の平均の厚さ測定方法]
まず、供試材をp-ニトロフェノール及び苛性ソーダを成分とする水溶液に10分間浸漬し、Sn被覆層を除去した。その後、蛍光X線膜厚計(セイコーインスツルメンツ株式会社;SFT3200)を用いて、Cu−Sn合金被覆層に含有されるSn成分の膜厚を測定した。測定条件は、検量線にSn/母材の単層検量線を用い、コリメータ径をφ0.5mmとした。得られた値をCu−Sn合金被覆層の平均の厚さと定義して算出した。
Subsequently, Table 3 shows the coating layer configuration of the obtained test material. The average thickness of the Cu—Sn alloy coating layer, the Cu content, the exposed area ratio, and the average thickness of the Sn coating layer were measured as follows. In addition, as for what exposed the Cu-Sn alloy coating layer on the outermost surface, the surface exposure space | interval was all in the said desirable range (0.01-0.5 mm).
[Method for measuring average thickness of Cu-Sn alloy coating layer]
First, the test material was immersed in an aqueous solution containing p-nitrophenol and caustic soda as components for 10 minutes to remove the Sn coating layer. Thereafter, the film thickness of the Sn component contained in the Cu—Sn alloy coating layer was measured using a fluorescent X-ray film thickness meter (Seiko Instruments Inc .; SFT3200). The measurement conditions were a single-layer Sn / base metal calibration curve as the calibration curve, and a collimator diameter of 0.5 mm. The obtained value was defined as the average thickness of the Cu—Sn alloy coating layer.

[Cu−Sn合金被覆層のCu含有量測定方法]
まず、供試材をp-ニトロフェノール及び苛性ソーダを成分とする水溶液に10分間浸漬し、Sn被覆層を除去した。その後、EDX(エネルギー分散型X線分光分析器)を用いて、Cu−Sn合金被覆層のCu含有量を定量分析により求めた。
[Cu−Sn合金被覆層の露出面積率測定方法]
供試材の表面を、EDX(エネルギー分散型X線分光分析器)を搭載したSEM(走査型電子顕微鏡)を用いて200倍の倍率で観察し、得られた組成像の濃淡(汚れや傷等のコントラストは除く)から画像解析によりCu−Sn合金被覆層の露出面積率を測定した。また、この組成像から、Cu−Sn合金被覆層の表面露出間隔を測定した。測定方向(引いた直線の方向)は、表面粗化処理の際に行った圧延又は研磨方向に直角な方向とした。図2にNo.1の組成像、図3にNo.3の組成像を示す。なお、No.1は研磨による表面粗化処理、No.3は圧延による表面粗化処理を行っている。
[Method for measuring Cu content of Cu-Sn alloy coating layer]
First, the test material was immersed in an aqueous solution containing p-nitrophenol and caustic soda as components for 10 minutes to remove the Sn coating layer. Thereafter, the Cu content of the Cu—Sn alloy coating layer was determined by quantitative analysis using EDX (energy dispersive X-ray spectrometer).
[Method for measuring exposed area ratio of Cu-Sn alloy coating layer]
The surface of the test material was observed at a magnification of 200 times using an SEM (scanning electron microscope) equipped with an EDX (energy dispersive X-ray spectrometer), and the resulting composition image was shaded (dirt and scratches). The exposed area ratio of the Cu—Sn alloy coating layer was measured by image analysis. Moreover, the surface exposure space | interval of the Cu-Sn alloy coating layer was measured from this composition image. The measurement direction (the direction of the drawn straight line) was a direction perpendicular to the rolling or polishing direction performed during the surface roughening treatment. In FIG. No. 1 composition image, No. 1 in FIG. 3 shows a composition image. In addition, No. No. 1 is a surface roughening treatment by polishing. 3 performs a surface roughening treatment by rolling.

[Sn被覆層の平均の厚さ測定方法]
まず、蛍光X線膜厚計(セイコーインスツルメンツ株式会社;SFT3200)を用いて、Sn被覆層の膜厚とCu−Sn合金被覆層に含有されるSn成分の膜厚の和を測定した。その後、p-ニトロフェノール及び苛性ソーダを成分とする水溶液に10分間浸漬し、Sn被覆層を除去した。再度、蛍光X線膜厚計を用いて、Cu−Sn合金被覆層に含有されるSn成分の膜厚を測定した。測定条件は、検量線にSn/母材の単層検量線を用い、コリメータ径をφ0.5mmとした。得られたSn被覆層の膜厚とCu−Sn合金被覆層に含有されるSn成分の膜厚の和から、Cu−Sn合金被覆層に含有されるSn成分の膜厚を差し引くことにより、Sn被覆層の平均の厚さを算出した。
[Method for measuring average thickness of Sn coating layer]
First, the sum of the film thickness of the Sn coating layer and the film thickness of the Sn component contained in the Cu—Sn alloy coating layer was measured using a fluorescent X-ray film thickness meter (Seiko Instruments Inc .; SFT3200). Then, it was immersed for 10 minutes in the aqueous solution which uses p-nitrophenol and caustic soda as components, and the Sn coating layer was removed. Again, the film thickness of the Sn component contained in the Cu—Sn alloy coating layer was measured using a fluorescent X-ray film thickness meter. The measurement conditions were a single-layer Sn / base metal calibration curve as the calibration curve, and a collimator diameter of 0.5 mm. By subtracting the film thickness of the Sn component contained in the Cu-Sn alloy coating layer from the sum of the film thickness of the obtained Sn coating layer and the film thickness of the Sn component contained in the Cu-Sn alloy coating layer, Sn The average thickness of the coating layer was calculated.

また、得られた供試材について、摩擦係数評価試験、高温放置後の接触抵抗評価試験及び塩水噴霧後の接触抵抗評価試験を、下記の要領で行った。その結果を、表3に合わせて示す。
[摩擦係数評価試験]
嵌合型接続部品における電気接点のインデント部の形状を模擬し、図4に示すような装置を用いて評価した。まず、各供試材から切り出した板材のオス試験片1を水平な台2に固定し、その上に表3の供試材No.7から切り出した半球加工材(内径をφ1.5mmとした)のメス試験片3をおいて被覆層同士を接触させた。続いて、メス試験片3に3.0Nの荷重(錘4)をかけてオス試験片1を押さえ、横型荷重測定器(アイコーエンジニアリング株式会社;Model−2152)を用いて、オス試験片1を水平方向に引っ張り(摺動速度を80mm/minとした)、摺動距離5mmまでの最大摩擦力F(単位:N)を測定した。摩擦係数を下記式(1)により求めた。なお、5はロードセル、矢印は摺動方向である。
摩擦係数=F/3.0 …(1)
Moreover, about the obtained test material, the friction coefficient evaluation test, the contact resistance evaluation test after leaving at high temperature, and the contact resistance evaluation test after salt water spraying were performed in the following manner. The results are also shown in Table 3.
[Friction coefficient evaluation test]
The shape of the indented portion of the electrical contact in the fitting type connecting part was simulated and evaluated using an apparatus as shown in FIG. First, a male test piece 1 of a plate material cut out from each test material was fixed to a horizontal base 2, and a test material No. The covering layers were brought into contact with each other by placing a female test piece 3 of a hemispherical work piece cut out from 7 (with an inner diameter of φ1.5 mm). Subsequently, the male test piece 1 is pressed by applying a load of 3.0 N (weight 4) to the female test piece 3, and using a horizontal load measuring device (Aiko Engineering Co., Ltd .; Model-2152). The sample was pulled in the horizontal direction (sliding speed was 80 mm / min), and the maximum frictional force F (unit: N) up to a sliding distance of 5 mm was measured. The coefficient of friction was determined by the following formula (1). In addition, 5 is a load cell and the arrow is a sliding direction.
Friction coefficient = F / 3.0 (1)

[高温放置後の接触抵抗評価試験]
各供試材に対し、大気中にて160℃×120hrの熱処理を行った後、接触抵抗を四端子法により、開放電圧20mV、電流10mA、無摺動の条件にて測定した。
[塩水噴霧後の接触抵抗評価試験]
各供試材に対し、JIS Z2371−2000に基づいて、5%NaCl水溶液を用いて35℃×6hrの塩水噴霧試験を行った後、接触抵抗を四端子法により、開放電圧20mV、電流10mA、無摺動の条件にて測定した。
[Evaluation test for contact resistance after standing at high temperature]
Each test material was heat-treated at 160 ° C. for 120 hours in the air, and then contact resistance was measured by a four-terminal method under an open voltage of 20 mV, a current of 10 mA, and no sliding.
[Contact resistance test after spraying with salt water]
Each test material was subjected to a salt spray test of 35 ° C. × 6 hr using a 5% NaCl aqueous solution based on JIS Z2371-2000, and then contact resistance was determined by a four-terminal method using an open voltage of 20 mV, a current of 10 mA, Measurement was performed under non-sliding conditions.

表3に示すように、No.1〜6は、被覆層構成に関して本発明に規定する要件を満たし、摩擦係数が低く、高温長時間放置後の接触抵抗及び塩水噴霧後の接触抵抗のいずれについても、優れた特性を示す。
一方、No.7,8は、母材表面が平滑であったため、Cu−Sn合金被覆層の露出面積率が0%であり、摩擦抵抗が大きかった。No.9,10は、母材表面の算術平均粗さRaが比較的大きい割りに、Snめっき層の平均の厚さが薄く、Cu−Sn合金被覆層の露出面積率が大きくなりすぎ、接触抵抗が高くなった。No.9,10については、Snめっき層の平均の厚さを増やせば、本発明の要件を満たす被覆層構成を得ることができる。
As shown in Table 3, no. Nos. 1 to 6 satisfy the requirements stipulated in the present invention with respect to the coating layer structure, have a low coefficient of friction, and exhibit excellent characteristics in both contact resistance after standing at high temperature for a long time and contact resistance after salt spray.
On the other hand, no. In Nos. 7 and 8, since the surface of the base material was smooth, the exposed area ratio of the Cu—Sn alloy coating layer was 0%, and the frictional resistance was large. No. In Nos. 9 and 10, the arithmetic average roughness Ra of the base material surface is relatively large, but the average thickness of the Sn plating layer is thin, the exposed area ratio of the Cu—Sn alloy coating layer is too large, and the contact resistance is low. It became high. No. As for 9, 10, if the average thickness of the Sn plating layer is increased, a coating layer configuration satisfying the requirements of the present invention can be obtained.

各々の表面粗化処理を行ったCu合金No.1の母材に対して、厚さが0.15μmのCuめっきを施し、さらに各々の厚さのSnめっきを施した後、280℃で10秒間のリフロー処理を行うことにより供試材(No.11〜19)を得た。その製造条件を表4に示す。なお、母材の表面粗さパラメータのうち、凹凸の平均間隔Smに関しては、全て前記望ましい範囲内(0.01〜0.5mm)にあった。また、表4に記載されたCuめっき及びSnめっきの平均の厚さについては、上記実施例1と同様の要領で測定した。   Each of the Cu alloy no. The base material of No. 1 was subjected to Cu plating with a thickness of 0.15 μm, and further subjected to Sn plating of each thickness, and then subjected to a reflow treatment at 280 ° C. for 10 seconds to give a specimen (No. 11-19). The production conditions are shown in Table 4. In addition, among the surface roughness parameters of the base material, the average interval Sm of the unevenness was all within the desired range (0.01 to 0.5 mm). Moreover, about the average thickness of Cu plating and Sn plating which were described in Table 4, it measured in the way similar to the said Example 1. FIG.

続いて、得られた供試材の被覆層構成を、表5に示す。Cu−Sn合金被覆層の平均の厚さ、Cu含有量、露出面積率及びSn被覆層の平均の厚さについては、上記実施例1と同様の要領で測定した。なお、Cu−Sn合金被覆層が最表面に露出したものは、その表面露出間隔が全て前記望ましい範囲内(0.01〜0.5mm)にあった。   Then, the coating layer structure of the obtained test material is shown in Table 5. The average thickness of the Cu—Sn alloy coating layer, the Cu content, the exposed area ratio, and the average thickness of the Sn coating layer were measured in the same manner as in Example 1. In addition, as for what exposed the Cu-Sn alloy coating layer on the outermost surface, the surface exposure space | interval was all in the said desirable range (0.01-0.5 mm).

また、得られた供試材について、摩擦係数評価試験、高温放置後の接触抵抗評価試験及び塩水噴霧後の接触抵抗評価試験を、上記実施例1と同様の要領で行った。その結果を表5に合わせて示す。   Moreover, about the obtained test material, the friction coefficient evaluation test, the contact resistance evaluation test after leaving at high temperature, and the contact resistance evaluation test after salt spray were performed in the same manner as in Example 1. The results are also shown in Table 5.

表5に示すように、No.11〜16については、被覆層構成に関して本発明に規定する要件を満たし、摩擦係数が低く、高温長時間放置後の接触抵抗及び塩水噴霧後の接触抵抗のいずれについても、優れた特性を示す。
一方、No.17〜19は、Sn被覆層の平均の厚さが薄く、接触抵抗が高くなった。なお、No.18,19については、母材表面の算術平均粗さRaの大きさの割りにはSnめっき層の平均の厚さが薄かったためで、Snめっき層の平均の厚さを増やせば、本発明の要件を満たす被覆層構成が得られる。しかし、No.17については、母材表面の算術平均粗さRaが小さすぎるため、Snめっき層の平均の厚さを増やしても、本発明の要件を満たす被覆層構成を得るのは難しい。
As shown in Table 5, no. About 11-16, the requirements prescribed | regulated to this invention regarding the coating layer structure are satisfy | filled, a friction coefficient is low, and the outstanding characteristic is shown also about any of the contact resistance after leaving high temperature for a long time and the contact resistance after salt water spraying.
On the other hand, no. In Nos. 17 to 19, the average thickness of the Sn coating layer was thin, and the contact resistance was high. In addition, No. For Nos. 18 and 19, the average thickness of the Sn plating layer was thin relative to the size of the arithmetic average roughness Ra of the surface of the base material. Therefore, if the average thickness of the Sn plating layer is increased, A coating layer configuration that meets the requirements is obtained. However, no. Regarding 17, the arithmetic average roughness Ra on the surface of the base material is too small, so even if the average thickness of the Sn plating layer is increased, it is difficult to obtain a coating layer configuration that satisfies the requirements of the present invention.

表面粗化処理を行ったCu合金No.1の母材に対して、厚さが0.15μmのCuめっきを施し、さらに各々の厚さのSnめっきを施した後、各々のリフロー処理を行うことにより供試材(No.20〜26)を得た。その製造条件を表6に示す。なお、母材の表面粗さパラメータのうち、凹凸の平均間隔Smに関しては、全て前記望ましい範囲内(0.01〜0.5mm)にあった。また、表6に記載された、Cuめっき及びSnめっきの平均の厚さについては、上記実施例1と同様の要領で測定した。   Cu alloy no. The base material of No. 1 was subjected to Cu plating with a thickness of 0.15 μm, and further subjected to Sn plating of each thickness, and then subjected to each reflow treatment to obtain a specimen (No. 20 to 26). ) The production conditions are shown in Table 6. In addition, among the surface roughness parameters of the base material, the average interval Sm of the unevenness was all within the desired range (0.01 to 0.5 mm). Moreover, about the average thickness of Cu plating and Sn plating which were described in Table 6, it measured in the way similar to the said Example 1. FIG.

続いて、得られた供試材の被覆層構成を、表7に示す。なお、Cu−Sn合金被覆層の平均の厚さ、Cu含有量、露出面積率及びSn被覆層の平均の厚さについては、上記実施例1と同様の要領で測定した。なお、Cu−Sn合金被覆層が最表面に露出したものは、その表面露出間隔が全て前記望ましい範囲内(0.01〜0.5mm)にあった。   Subsequently, Table 7 shows the coating layer configuration of the obtained test material. In addition, about the average thickness of Cu-Sn alloy coating layer, Cu content, an exposed area rate, and the average thickness of Sn coating layer, it measured in the same way as the said Example 1. FIG. In addition, as for what exposed the Cu-Sn alloy coating layer on the outermost surface, the surface exposure space | interval was all in the said desirable range (0.01-0.5 mm).

また、得られた供試材について、摩擦係数評価試験、高温放置後の接触抵抗評価試験及び塩水噴霧後の接触抵抗評価試験を、上記実施例1と同様の要領で行った。その結果を表7に合わせて示す。   Moreover, about the obtained test material, the friction coefficient evaluation test, the contact resistance evaluation test after leaving at high temperature, and the contact resistance evaluation test after salt spray were performed in the same manner as in Example 1. The results are also shown in Table 7.

表7に示すように、No.20〜23については、被覆層構成に関して本発明に規定する要件を満たし、摩擦係数が低く、高温長時間放置後の接触抵抗及び塩水噴霧後の接触抵抗のいずれについても、優れた特性を示す。
一方、No.24は、リフロー処理時間が短かったため、Cu−Sn合金被覆層の形成が不十分で平均の厚さが不足し、接触抵抗が高くなった。No.25は、リフロー処理温度が低かったためCu−Sn合金被覆層のCu含有量が少なくなり、摩擦係数が高くなった。さらに、リフロー処理時間が長かったため、接触抵抗が高くなった。No.26は、リフロー処理温度が高く、被覆層YのCu含有量が多くなりすぎ、接触抵抗が高くなった。
As shown in Table 7, no. About 20-23, the requirements prescribed | regulated to this invention regarding the structure of a coating layer are satisfy | filled, a friction coefficient is low, and the outstanding characteristic is shown also about any of the contact resistance after high temperature long time leaving and the contact resistance after salt spray.
On the other hand, no. In No. 24, since the reflow treatment time was short, the formation of the Cu—Sn alloy coating layer was insufficient, the average thickness was insufficient, and the contact resistance was high. No. In No. 25, since the reflow treatment temperature was low, the Cu content of the Cu—Sn alloy coating layer was reduced, and the friction coefficient was increased. Furthermore, since the reflow treatment time was long, the contact resistance was high. No. In No. 26, the reflow treatment temperature was high, the Cu content of the coating layer Y was excessive, and the contact resistance was high.

各々の表面粗化処理を行った(No.33,34は行わず)Cu合金No.1,No.2の母材に対して、厚さが0.3μmのNiめっき、厚さが0.15μmのCuめっきを施し、さらに厚さ1.0μmのSnめっきを施した後、280℃で10秒間のリフロー処理を行うことにより供試材(No.27〜36)を得た。その製造条件を表8に示す。なお、母材の表面粗さパラメータのうち、凹凸の平均間隔Smに関しては、全て前記望ましい範囲内(0.01〜0.5mm)にあった。また、表8に記載されたNiめっき及びSnめっきの平均の厚さについては、下記要領で測定し、Cuめっきの平均の厚さについては、上記実施例1と同様の要領で測定した。
[NiめっきおよびSnめっきの平均の厚さ測定方法]
蛍光X線膜厚計(セイコーインスツルメンツ株式会社;SFT3200)を用いて平均の厚さを算出した。測定条件は、検量線にSn/Ni/母材の2層検量線を用い、コリメータ径をφ0.5mmとした。
Each surface roughening treatment was performed (Nos. 33 and 34 were not performed). 1, No. 1 The base material of No. 2 was subjected to Ni plating with a thickness of 0.3 μm, Cu plating with a thickness of 0.15 μm, and further Sn plating with a thickness of 1.0 μm, and then at 280 ° C. for 10 seconds. A sample material (Nos. 27 to 36) was obtained by performing the reflow treatment. Table 8 shows the production conditions. In addition, among the surface roughness parameters of the base material, the average interval Sm of the unevenness was all within the desired range (0.01 to 0.5 mm). Moreover, about the average thickness of Ni plating and Sn plating which were described in Table 8, it measured in the following way, and it measured in the same way as the said Example 1 about the average thickness of Cu plating.
[Measuring method of average thickness of Ni plating and Sn plating]
The average thickness was calculated using a fluorescent X-ray film thickness meter (Seiko Instruments Inc .; SFT3200). The measurement conditions were Sn / Ni / base metal two-layer calibration curve for the calibration curve and the collimator diameter was φ0.5 mm.

続いて、得られた供試材の被覆層構成を、表9に示す。なお、Cu−Sn合金被覆層の平均の厚さ、Cu含有量、露出面積率及びSn被覆層の平均の厚さについては、上記実施例1と同様の要領で測定した。なお、Cu−Sn合金被覆層が最表面に露出したものは、その表面露出間隔が全て前記望ましい範囲内(0.01〜0.5mm)にあった。   Subsequently, Table 9 shows the coating layer configuration of the obtained test material. In addition, about the average thickness of Cu-Sn alloy coating layer, Cu content, an exposed area rate, and the average thickness of Sn coating layer, it measured in the same way as the said Example 1. FIG. In addition, as for what exposed the Cu-Sn alloy coating layer on the outermost surface, the surface exposure space | interval was all in the said desirable range (0.01-0.5 mm).

また、表9に示した供試材の摩擦係数評価試験、高温放置後の接触抵抗評価試験及び塩水噴霧後の接触抵抗評価試験を、上記実施例1と同様の要領で行った。その結果を、表9に合わせて示す。   Moreover, the friction coefficient evaluation test of the test material shown in Table 9, the contact resistance evaluation test after being left at high temperature, and the contact resistance evaluation test after spraying with salt water were performed in the same manner as in Example 1. The results are also shown in Table 9.

表9に示すように、No.27〜32は、被覆層構成に関して本発明に規定する要件を満たし、摩擦係数が低く、高温長時間放置後の接触抵抗及び塩水噴霧後の接触抵抗のいずれについても、優れた特性を示す。また、Ni被覆層が形成されたことで、No.1〜6等と比較して、特に高温放置後の接触抵抗が低くなっている。
一方、No.33〜36についても、Ni被覆層が形成されたことで、No.7〜10等と比較して、特に高温放置後の接触抵抗が低くなっている。しかし、No.33,34は、母材表面が平滑であったため、Cu−Sn合金被覆層の露出面積率が0%であり、摩擦抵抗が大きかった。No.35,36は、母材表面の算術平均粗さRaが比較的大きい割りに、Snめっき層の平均の厚さが薄く、Cu−Sn合金被覆層の露出面積率が大きくなりすぎ、特に塩水噴霧後の接触抵抗が上昇した。No.35,36については、Snめっき層の平均の厚さを増やせば、本発明の要件を満たす被覆層構成を得ることができる。
As shown in Table 9, no. Nos. 27 to 32 satisfy the requirements defined in the present invention with respect to the coating layer structure, have a low coefficient of friction, and exhibit excellent characteristics in both contact resistance after standing at high temperature for a long time and contact resistance after salt spray. In addition, since the Ni coating layer was formed, Compared with 1-6 etc., the contact resistance especially after leaving at high temperature is low.
On the other hand, no. For Nos. 33 to 36, the Ni coating layer was formed. Compared with 7-10 etc., the contact resistance especially after leaving at high temperature is low. However, no. Since the base material surfaces of Nos. 33 and 34 were smooth, the exposed area ratio of the Cu—Sn alloy coating layer was 0%, and the frictional resistance was large. No. 35 and 36, the arithmetic average roughness Ra of the base material surface is relatively large, but the average thickness of the Sn plating layer is thin, and the exposed area ratio of the Cu—Sn alloy coating layer is too large. Later contact resistance increased. No. For 35 and 36, if the average thickness of the Sn plating layer is increased, a coating layer configuration that satisfies the requirements of the present invention can be obtained.

本発明に係る接続部品用導電材料の断面構造を模式的に示す概念図である。It is a conceptual diagram which shows typically the cross-section of the electrically-conductive material for connection components which concerns on this invention. 実施例No.1の供試材の最表面構造の走査電子顕微鏡組成像である。Example No. It is a scanning electron microscope composition image of the outermost surface structure of 1 specimen. 実施例No.3の供試材の最表面構造の走査電子顕微鏡組成像である。Example No. 3 is a scanning electron microscope composition image of the outermost surface structure of the specimen 3; 摩擦係数測定治具の概念図である。It is a conceptual diagram of a friction coefficient measuring jig.

符号の説明Explanation of symbols

A 母材
X Sn被覆層
Y Cu−Sn合金被覆層
1 オス試験片
2 台
3 メス試験片
4 錘
5 ロードセル
A Base material X Sn coating layer Y Cu-Sn alloy coating layer 1 Male test piece 2 units 3 Female test piece 4 Weight 5 Load cell

Claims (9)

  1. Cu板条からなる母材の表面に、Cu−Sn合金被覆層とSn被覆層がこの順に形成されており、前記Cu−Sn合金被覆層の材料表面露出面積率が3〜75%、平均の厚さが0.1〜3.0μm、かつCu含有量が20〜70at%であり、前記Sn被覆層の平均の厚さが0.2〜5.0μmであり、前記母材の表面は、少なくとも一方向の算術平均粗さRaが0.15μm以上で、全ての方向の算術平均粗さRaが4.0μm以下であることを特徴とする接続部品用導電材料。 A Cu—Sn alloy coating layer and a Sn coating layer are formed in this order on the surface of the base material made of Cu plate, and the exposed surface area ratio of the material of the Cu—Sn alloy coating layer is 3 to 75%. thickness 0.1 to 3.0 m, and a 20~70At% of Cu content, the average thickness of the Sn coating layer is Ri 0.2~5.0μm der, the surface of the base material The conductive material for connecting parts, wherein the arithmetic average roughness Ra in at least one direction is 0.15 μm or more and the arithmetic average roughness Ra in all directions is 4.0 μm or less .
  2. 前記母材表面と前記Cu−Sn合金被覆層の間にさらにCu被覆層を有することを特徴とする請求項1に記載された接続部品用導電材料。 The conductive material for connecting parts according to claim 1, further comprising a Cu coating layer between the surface of the base material and the Cu—Sn alloy coating layer.
  3. 前記母材表面と前記Cu−Sn合金被覆層の間にさらにNi被覆層が形成されていることを特徴とする請求項1に記載された接続部品用導電材料。 The conductive material for connecting parts according to claim 1, wherein a Ni coating layer is further formed between the surface of the base material and the Cu-Sn alloy coating layer.
  4. 前記Ni被覆層とCu−Sn合金被覆層との間にさらにCu被覆層を有することを特徴とする請求項3に記載された接続部品用導電材料。 The conductive material for connection parts according to claim 3, further comprising a Cu coating layer between the Ni coating layer and the Cu-Sn alloy coating layer.
  5. 前記Sn被覆層がリフロー処理により平滑化されたことを特徴とする請求項1〜4のいずれかに記載された接続部品用導電材料。 The conductive material for connecting parts according to claim 1 , wherein the Sn coating layer is smoothed by a reflow process.
  6. Cu板条からなる母材の表面に、Cuめっき層とSnめっき層をこの順に形成した後、リフロー処理を行い、Cu−Sn合金被覆層と、Sn被覆層をこの順に形成する接続部品用導電材料の製造方法において、前記母材の表面を、少なくとも一方向の算術平均粗さRaが0.15μm以上で、全ての方向の算術平均粗さRaが4.0μm以下の表面粗さとし、材料表面露出面積率が3〜75%、平均の厚さが0.1〜3.0μm、かつCu含有量が20〜70at%の前記Cu−Sn合金被覆層と、平均の厚さが0.2〜5.0μmの前記Sn被覆層を形成することを特徴とする接続部品用導電材料の製造方法。 After forming a Cu plating layer and a Sn plating layer in this order on the surface of the base material made of Cu plate strip, a reflow process is performed to form a Cu—Sn alloy coating layer and a Sn coating layer in this order. In the method for producing a material, the surface of the base material has a surface roughness having an arithmetic average roughness Ra of at least one direction of 0.15 μm or more and an arithmetic average roughness Ra of all directions of 4.0 μm or less. The Cu—Sn alloy coating layer having an exposed area ratio of 3 to 75%, an average thickness of 0.1 to 3.0 μm, and a Cu content of 20 to 70 at%, and an average thickness of 0.2 to A method for producing a conductive material for connecting parts, comprising forming the Sn coating layer of 5.0 μm.
  7. 前記母材表面と前記Cuめっき層の間に、Niめっき層を形成することを特徴とする請求項6に記載された接続部品用導電材料の製造方法。 The method for producing a conductive material for connecting parts according to claim 6 , wherein a Ni plating layer is formed between the surface of the base material and the Cu plating layer.
  8. Cu板条からなる母材の表面に、Snめっき層を形成した後、リフロー処理を行い、Cu−Sn合金被覆層と、Sn被覆層をこの順に形成する接続部品用導電材料の製造方法において、前記母材の表面を、少なくとも一方向の算術平均粗さRaが0.15μm以上で、全ての方向の算術平均粗さRaが4.0μm以下の表面粗さとし、材料表面露出面積率が3〜75%、平均の厚さが0.1〜3.0μm、かつCu含有量が20〜70at%の前記Cu−Sn合金被覆層と、平均の厚さが0.2〜5.0μmの前記Sn被覆層を形成することを特徴とする接続部品用導電材料の製造方法。 In the method for manufacturing a conductive material for connecting parts, in which a Sn plating layer is formed on the surface of a base material made of a Cu strip, and then a reflow process is performed to form a Cu-Sn alloy coating layer and a Sn coating layer in this order. The surface of the base material is a surface roughness having an arithmetic average roughness Ra of at least one direction of 0.15 μm or more and an arithmetic average roughness Ra of all directions of 4.0 μm or less. The Cu—Sn alloy coating layer having 75%, an average thickness of 0.1 to 3.0 μm, and a Cu content of 20 to 70 at%, and the Sn having an average thickness of 0.2 to 5.0 μm A method for producing a conductive material for connecting parts, wherein a coating layer is formed.
  9. 前記リフロー処理を、前記Snめっき層の融点以上、600℃以下の温度で3〜30秒間行うことを特徴とする請求項6〜8のいずれかに記載された接続部品用導電材料の製造方法。 The method for producing a conductive material for connection parts according to any one of claims 6 to 8 , wherein the reflow treatment is performed at a temperature of not lower than the melting point of the Sn plating layer and not higher than 600 ° C for 3 to 30 seconds.
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