JPS58197291A - Plating method with tin or tin alloy - Google Patents

Abstract

PURPOSE:To obtain a tin plating film having excellent adhesion and solderability, by etching the underlying layer for copper plating provided on an electrically conductive surface to roughen the same then plating tin on the outside thereof. CONSTITUTION:An electrically conductive material such as oxygen-free copper or a copper alloy is subjected to cathodic degreasing, anodic degreasing and pickling, whereafter an org. compd. having the effects for brightening, smoothing and dispersing is added to a sulfuric acid bath using copper sulfate or the like and copper plating is applied on said material to form a copper plated underlying layer. The etching treatment for removing the above-mentioned org. compd. and to dissolve the underlying layer of copper by 0.01-1mu thickness to roughen the surface is then applied on said layer by using an etching soln. of H2SO4- H2O2. Tin or a tin alloy is plated on the outside thereof continuously.

Description

【発明の詳細な説明】 本発明は密着性及び半田性に優れた錫又は錫合金（以下
錫という）のメッキを行う方法の改良に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for plating tin or a tin alloy (hereinafter referred to as tin) with excellent adhesion and solderability.

一般に電気導電性材の表面に錫メッキを施した線１条材
は、これを曲げ、加工、打抜き加工等を行い樹脂モール
ド等を施した後、スイッチ、コネクターの端子接点等の
電子部品の用途に広く利用されている。In general, a single strip of electrically conductive material with tin plating on its surface is bent, processed, punched, etc., and then molded with resin, etc., and then used as electronic components such as switches and terminal contacts of connectors. It is widely used in

従来このメッキ方法としては、電気導電性材の表面にＣ
ｕメッキ工程と錫メツキ工程とにより行うものであるが
、銅メッキを行った後水洗又は水洗と希硫酸とによる活
性処理を施し錫メッキを行っているものであるが、密着
性並びに半田付は性において十分なものをえることが出
来なかった。即ち、錫メツキ製品を熱処理例えば１５０
℃Ｘ１ｈｒ後密着曲げ試験では錫メッキの被膜は剥離し
ないが１００℃Ｘ５００ｈｒａ後においては密着曲げ剥
離現象をおこし且つプレス打抜き加工において打抜き切
断端面部に錫メッキの被膜に剥離を生ずる。Conventionally, in this plating method, C was applied to the surface of the electrically conductive material.
This is done through a U plating process and a tin plating process, and after copper plating, tin plating is performed by washing with water or activating with water and dilute sulfuric acid, but the adhesion and soldering are I couldn't get enough in terms of sex. That is, the tin-plated product is heat-treated, e.g.
In the close bending test after 1 hour at 100° C., the tin plating film does not peel off, but after 500 hours at 100° C., a close bending peeling phenomenon occurs, and during press punching, the tin plating film peels off on the punched end face.

この剥離の現象は銅メツキ液中に含まれる不純物として
の有機物、銅メツキ添加剤としての有機物に基因するも
のと考えられ銅メッキの下地層と錫メッキとの間、即ち
主に下地銅−錫。This peeling phenomenon is thought to be caused by organic substances as impurities contained in the copper plating solution and organic substances as copper plating additives. .

銅合金層間でおこすが、まれに錫、銅合金層−純錫層間
でおこすことが認められた。It occurs between copper alloy layers, but rarely occurs between tin and copper alloy layers and pure tin layers.

なおこの剥離現象は錫メツキ材が使用される電子部品、
特に高密度の脚線やスイッチ端子などの極間において錫
の剥離被膜が導通不良の原因となっていた。This peeling phenomenon occurs in electronic parts where tin-plated materials are used.
In particular, peeled-off tin coatings caused poor continuity between high-density leg wires and switch terminals.

又、半田付特性においても下地銅メッキ層の表面に有機
化合物による薄膜が付着することによシ、特に添加剤を
混入せる光沢メッキの場合には半田付特性を阻害し、回
路に組込む際に半田付は作業が不良になることが頻繁に
おこっていた。In addition, the soldering properties are also affected by the adhesion of a thin film of organic compounds to the surface of the base copper plating layer, which impairs the soldering properties, especially in the case of bright plating that incorporates additives, making it difficult to incorporate into circuits. Soldering often resulted in poor workmanship.

本発明はかかる現状に鑑み鋭意研究を行った結果、密着
性並びに半田付は性に優れた錫メツキ方法を見出したも
のである。即ち本発明方法は電気導電性材の表面に銅メ
ッキの下地層を設けた後、連続してエツチング処理を行
って該下地層の０．０１〜１μを溶解し、その外側に錫
メッキを行うことを特徴とするものである。The present invention has been made in view of the current situation and as a result of intensive research, we have discovered a tin plating method with excellent adhesion and soldering properties. That is, in the method of the present invention, after providing a base layer for copper plating on the surface of an electrically conductive material, etching is continuously performed to dissolve 0.01 to 1 μm of the base layer, and tin plating is applied to the outside of the base layer. It is characterized by this.

本発明において電気導電性材としては、無酸素銅、タフ
ピッチ銅、黄銅、青銅、Ｃｕ−Ｆｅ系合金、Ｃｕ−Ｂｅ
系合金、Ｃｕ−Ｔｉ系合金、Ｃｕ−Ｎｉ系合金等である
。In the present invention, electrically conductive materials include oxygen-free copper, tough pitch copper, brass, bronze, Cu-Fe alloy, Cu-Be
alloy, Cu-Ti alloy, Cu-Ni alloy, etc.

この電気導電性材を陰極脱脂、陽極脱脂を行うものであ
るが、脱脂剤としては例えばエンドックス１１４　（シ
ャツぐンメタルフィニッシングカンパ二−社商品名）等
がある。This electrically conductive material is subjected to cathodic degreasing and anodic degreasing, and examples of the degreasing agent include ENDOX 114 (trade name of Shirtgun Metal Finishing Company).

次いでＨ２ＳＯ４，ＨＣｔ　、　ＨＢＦ４　　等の水溶
液により酸洗を行い、銅メッキを行って下地層を設ける
。その液としては硫酸銅による硫酸浴、ピロリン酸銅に
よるビロリン酸浴、ホウフッ化銅によるホウ７ツ化浴、
スルファミン酸銅によるスルファミン酸浴、シャン化銅
による青化浴等を使用する。Next, pickling is performed using an aqueous solution of H2SO4, HCt, HBF4, etc., and copper plating is performed to provide an underlayer. The liquids include a sulfuric acid bath with copper sulfate, a birophosphate bath with copper pyrophosphate, a borosulfide bath with copper borofluoride,
A sulfamic acid bath using copper sulfamate, a curing bath using copper syanide, etc. are used.

なおその添加剤としては光沢、平滑、分散の作用を有す
る成分が含まれ、光沢成分としてはチオカル７げニル（
’Ｘ＝Ｓ　）やスルフィード、ポリスルフィード［−（
−８−）−Ｘ）などの有機Ｓ化合物、又平滑成分として
は染料（フェナジン、トリフェニルメタン、アジン）ゼ
ラチン、ゼラチン、デキストリン、芳香族スルホン酸（
ナフタレンジスルホン酸ｅｔｃ、）がある。又分散成分
としてはニオン活性剤（ポリエーテル）、アニオン活性
剤（硫酸工扶チル）等がある。The additives include components that have gloss, smoothing, and dispersion effects, and the gloss component is thiocar-7genyl (
'X=S), sulfide, polysulfide [-(
-8-)-X) and other organic S compounds, and smoothing components include dyes (phenazine, triphenylmethane, azine), gelatin, gelatin, dextrin, aromatic sulfonic acids (
naphthalene disulfonic acid, etc.). Dispersion components include ionic activators (polyether), anionic activators (butyl sulfate), and the like.

而して本発明方法は特にエツチング液例えばＨ２Ｓ０４
−Ｈ２Ｏ２，ＨＢＦ４−Ｈ２Ｏ２又は過硫安−Ｈ２ＳＯ
４等を使用して上記有機化合物を取除くと共に銅メッキ
の外観を阻わない程度、即ち銅の下地層の厚さ０．０１
〜１μを溶解して粗面化するエツチング処理を施すもの
である。The method of the invention is particularly suitable for etching solutions such as H2S04.
-H2O2, HBF4-H2O2 or ammonium persulfate-H2SO
4 or the like to remove the organic compound and to the extent that it does not interfere with the appearance of the copper plating, that is, the thickness of the copper base layer is 0.01
An etching process is performed to dissolve ~1μ and roughen the surface.

エツチングによる溶解厚みを０．０１〜１．　ｔｔに限
定した理山は、０．０１μ未満の場合には密着性、半田
付は性に効果が々く又１μを超えた場合には外観光沢を
阻害し且つ溶解厚みだけ余分に厚くメッキをしなければ
ならず生産性が劣シコスト高になるためである。The thickness of the solution by etching is 0.01 to 1. If the thickness is less than 0.01μ, it will have a great effect on adhesion and soldering properties, and if it exceeds 1μ, it will inhibit the appearance gloss and the plating should be made as thick as the melting thickness. This is because productivity is low and costs are high.

然る後通常の方法によシ錫メッキを行って本発明錫メツ
キ製品を得るものである。Thereafter, tin plating is performed by a conventional method to obtain the tin-plated product of the present invention.

次に本発明の実施例について説明する。Next, examples of the present invention will be described.

実施例（１） 厚さ０．２５ｍｍ＋巾２００ｍｍの７／３黄銅条を市販
の、ソヤノやンメタルフィニッシング社脱脂剤、クリー
ナ１６０（商品名）４５ｇ／ｌ、温度６５〜７５℃の水
溶液中にて電流密度（ＤＣ）３Ａ／ｄｍ２によ９２０秒
間陰極脱脂を行い、更に電流密度（ＤＣ）　２Ａ７ｄｍ
２により１０秒間陽極脱脂を行った後水洗した。Example (1) A 7/3 brass strip with a thickness of 0.25 mm and a width of 200 mm was placed in a commercially available aqueous solution of Soyano Metal Finishing Co., Ltd.'s degreaser, Cleaner 160 (trade name), 45 g/l, at a temperature of 65 to 75°C. Cathode degreasing was performed for 920 seconds at a current density (DC) of 3A/dm2, and further at a current density (DC) of 2A7dm.
After performing anodic degreasing for 10 seconds in accordance with No. 2, washing was performed with water.

５− 次いで１０％Ｈ２ＳＯ４水溶液によ！１ｌ１１ｏ秒間酸
洗いを行い、硫酸鋼メッキ浴（Ｃｕ５０　ｇ／ｌ、Ｈ２
ＳＯ４５０１１／Ｉｔ　、　（ＮＩ（２）Ｃ８０，０１
ｇ／１３　、　デキストリン（Ｃ６Ｈ２００５）ｎ　ｏ
、ｏ　Ｉ　ｇ／１１．　ＨＣｔＯ，Ｏ］、２．９／Ａ’
）を用いて電流密度５Ａ／ｄｍ２によシ厚さ１．２μの
銅メッキの下地層を設けた。しかる後連続して水洗しＨ
２ＳＯ４２００９／ｌ、Ｈ２Ｏ２１０ｇ／ｌ、アルコー
ル１ｏｃｒ。5- Then with 10% H2SO4 aqueous solution! Pickling was carried out for 1l11o seconds, and a sulfuric acid steel plating bath (Cu50 g/l, H2
SO45011/It, (NI(2)C80,01
g/13, dextrin (C6H2005) no
, o I g/11. HCtO,O], 2.9/A'
) was used to provide a copper plating base layer with a thickness of 1.2 μm at a current density of 5 A/dm 2 . After that, wash continuously with water.
2SO4 2009/l, H2O2 10g/l, alcohol 1ocr.

Ａからなるエツチング液中に４秒間浸漬し、下地層の約
０．０５μを溶解した。It was immersed in an etching solution consisting of A for 4 seconds to dissolve about 0.05μ of the underlayer.

次いで錫メッキ液（５ｎＳＯ４４０Ｖｌ、　Ｈ２ＳＯ４
１５０νｌ、クレゾールスルオ（ン酸１１０Ｖ１．βナ
フトール１．２ｇ／１．ゼラチン２．３ｇ／ｌ）により
厚さ１μ。Next, tin plating solution (5nSO440Vl, H2SO4
150 νl, 1μ thick with cresol sulphur (110V 1.β naphthol 1.2 g/1. gelatin 2.3 g/l).

１．５μ、及び２μの錫メッキを行い水洗乾燥して本発
明錫メッキ黄銅条をえた。Tin plating of 1.5μ and 2μ was performed, washed with water, and dried to obtain a tin-plated brass strip of the present invention.

斯くして得た本発明錫メッキ黄銅条を１００℃Ｘ５００
ｈｒｓの熱処理を行った後、１８ｏ０密着折シ曲げ試験
及びプレス打抜試験（クリアランスζ２／Ｚｏｏ　）に
よシ被膜の剥離の有無を測定したが、何れも剥離現象が
認められなかった。The thus obtained tin-plated brass strip of the present invention was heated at 100°C x 500°C.
After the heat treatment for hrs, the presence or absence of peeling of the coating was measured by a 18o0 close bending test and a press punching test (clearance ζ2/Zoo), but no peeling phenomenon was observed in either case.

実施例（２） ６− 実施例（１）と同様の黄銅条を使用し、実施例（１）と
同様に脱脂−酸洗−銅メツキ下地層−エツチング処理を
行った。Example (2) 6- Using the same brass strip as in Example (1), degreasing, pickling, copper plating base layer, and etching were performed in the same manner as in Example (1).

次いで下記半田メッキ液 Ｓ　ｎ　（ＢＦ　４　）２　　　　　　　　２６０１１
／１２Ｐｂ（ＢＦ’４）２２５みｑ ＨＢＦ４２００ｇ／ｌ 光沢剤　　　　東邦レーヨン社製 Ｓ　　　　　　　　　　　　６０Ｑ／ＩＢ　　　　　　
　　　　　　７　ｃＣ／１ホルマリン（３７チ）　　　
　　　、２０Ｃｎ／７硼酸　　　　１０ｇ／ｌ を使用し、浴温１８℃にて厚さ１μ、２μ、３μ及び４
μの錫メッキを行い水洗、乾燥して本発明錫メッキ黄銅
条をえた。Next, the following solder plating solution S n (BF 4 )2 26011
/12Pb (BF'4) 225miq HBF4200g/l Brightener Toho Rayon Co., Ltd. S 60Q/IB
7 cC/1 formalin (37 c)
, using 10g/l of 20Cn/7 boric acid, at a bath temperature of 18°C, with thicknesses of 1μ, 2μ, 3μ and 4μ.
A tin-plated brass strip of the present invention was obtained by tin-plating, washing with water, and drying.

斯くして得だ本発明錫メッキ黄銅条を実施例（１）と同
様の試験を行ったが、何等剥離現象が認められなかった
。The thus obtained tin-plated brass strip of the present invention was subjected to the same test as in Example (1), but no peeling phenomenon was observed.

比較例（１） 実施例（１）と同様の黄銅条を使用しエツチング処理工
程を行うことなく、単に水洗工程のみを行い、その他は
すべて実施例（１）と同様にして錫メツキ層厚１μ、１
．５μ及び２μの比較例錫メツキ銅条をえた。Comparative Example (1) Using the same brass strip as in Example (1), only a water washing process was performed without performing an etching process, and all other conditions were the same as in Example (1), with a tin plating layer thickness of 1 μm. ,1
．． Comparative tin-plated copper strips of 5μ and 2μ were obtained.

比較例（２） 実施例（２）と同様の黄銅条を使用し、エツチング処理
の代りに５％Ｈ２ＳＯ４水溶液により処理を行い、その
他はすべて実施例（２）と同様にして錫メッキ厚１μ、
２μ、３μ及び４μの比較例錫メツキ銅条をえた。Comparative Example (2) The same brass strip as in Example (2) was used, but instead of etching, it was treated with a 5% H2SO4 aqueous solution, and everything else was the same as in Example (2), with a tin plating thickness of 1μ,
Comparative tin-plated copper strips of 2μ, 3μ and 4μ were obtained.

比較例（３） 実施例（２）と同様の黄銅条を使用し、エツチング処理
液としてＨ２Ｈ２ＳＯ４２Ｏ０，■２０２１ｇ／ｌ、ア
ルコール２ｃｆＪｌを使用し、銅下地層の被膜厚を約０
．００５μ溶解してエツチング処理を行った以外はすべ
て実施例（２）と同様にして錫メッキ厚１μ、２μ、３
μ、及び４μ　の比較例錫メツキ銅条をえた。Comparative Example (3) Using the same brass strip as in Example (2), using H2H2SO42O0, ■2021g/l and alcohol 2cfJl as the etching treatment liquid, the film thickness of the copper underlayer was reduced to approximately 0.
．． The tin plating thickness was 1μ, 2μ, and 3μ in the same manner as in Example (2) except that 0.005μ was dissolved and the etching treatment was performed.
Comparative tin-plated copper strips of 4μ and 4μ were obtained.

斯くして得た比較例（１）〜（３）の錫メッキ黄銅条に
ついて実施例（１）と同様に密着性及びプレス打抜性を
夫々試験した結果、何れも錫メツキ膜に剥離現象が認め
られた。The tin-plated brass strips of Comparative Examples (1) to (3) thus obtained were tested for adhesion and press punchability in the same manner as in Example (1). Admitted.

更に、本発明錫メッキ黄銅条及び比較例錫メッキ黄銅条
について半田付特性（ハンダ濡れ面積）を下記に示す試
験方法によシ測定した。その結果は第１表に示す通りで
ある。Furthermore, the soldering characteristics (solder wet area) of the tin-plated brass strip of the present invention and the tin-plated brass strip of the comparative example were measured using the test method shown below. The results are shown in Table 1.

即ち２５Ｘ２５Ｘ０．２５＋ｎｍの試験片をＭｉＬ　−
ＳＴＤ　−２０２Ｄ　、　２０８　Ｂ　（垂直式浸漬法
）に準じて行った。That is, a 25X25X0.25+nm test piece was MiL −
It was carried out according to STD-202D, 208B (vertical dipping method).

まずアセトン２分浸漬後乾燥し２５％−Ｗ、Ｗロジンア
ルコールフラックス中に５秒浸漬、乾燥し、６０／４０
ハンダ（２３０±１℃）１±０．１秒浸漬した後取出し
アセトン中に浸漬、インプロビルアルコール中に浸漬し
乾燥した。なお浸漬面積は２５Ｘ１２．５調である。First, dipped in acetone for 2 minutes, dried, dipped in 25%-W, W rosin alcohol flux for 5 seconds, dried, 60/40
After being immersed in solder (230±1° C.) for 1±0.1 seconds, it was taken out and immersed in acetone, then immersed in Improvil alcohol, and dried. Note that the immersion area is 25 x 12.5 scale.

９− １０− 以上詳述した如く本発明方法によれば、密着性及び半田
付は特性に優れた錫メッキ線、条体を得る等顕著な効果
を有する。9-10- As detailed above, the method of the present invention has remarkable effects such as obtaining tin-plated wires and strips with excellent adhesion and soldering properties.

出願人代理人　　弁理士　鈴　江　武　彦＝１１−Applicant's agent: Patent attorney Suzue Takehiko = 11-

Claims (1)

【特許請求の範囲】[Claims] 電気導電性材の表面に銅メッキの下地層を設けた後、エ
ツチング処理を行って該下地層の０．０１〜１μを溶解
し、その外側に連ｉ又は錫合金のメッキを行うことを特
徴とする錫又は錫合金のメッキ方法。After providing a copper plating base layer on the surface of the electrically conductive material, etching is performed to dissolve 0.01 to 1μ of the base layer, and the outside thereof is plated with copper or tin alloy. A method of plating tin or tin alloy.