JPH01165757A - Production of surface-treated steel sheet for lead frame having excellent corrosion resistance, platability and solderability - Google Patents

Abstract

PURPOSE:To develop a surface-treated steel sheet for lead frames having excellent corrosion resistance, platability and solderability by forming a coating layer of Ni, Co or Ni-Co alloy at an adequate thickness on the surface of a cold rolled steel sheet contg. a specific ratio of Cr and subjecting the steel sheet to a heating diffusion treatment. CONSTITUTION:The surface of the cold rolled sheet of the alloy steel contg., by weight %, <0.30% C, 0.005-0.10% acid soluble Al, 3-10.5% Cr, or further 1 or >=2 kinds of 0.05-1.0% Cu, 0.05-3% Ni and 0.05-0.5% Mo is degreased and cleaned and thereafter, the surface is subjected to an activation treatment by pickling, etc. A plating layer is then formed on the surface thereof by electroplating of Ni, Co or Ni-Co alloy at 100-3000mg/m<2> deposition per face of the cold rolled steel sheet; thereafter, the steel sheet is subjected to a heating treatment for <=180 seconds in a 450 deg.C recrystallization temp. range in a nonoxidizing atmosphere to diffuse the Ni, Co or Ni-Co alloy, etc., of the plating metal into the steel sheet.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、耐食性にすぐれるとともに、リードフレーム
製造工程における打抜き加工性（スタンピング性）に必
要な材質性能、めっき性能或いははんだ性能にすぐれた
リードフレーム用表面処理鋼板の製造法に関するもので
ある。[Detailed Description of the Invention] (Industrial Application Field) The present invention has excellent corrosion resistance, and also has excellent material performance, plating performance, or solder performance necessary for stamping workability (stampability) in the lead frame manufacturing process. The present invention relates to a method of manufacturing a surface-treated steel sheet for lead frames.

（従来の技術） 近時、エレクトロニクス分野において、集積回路（ＩＣ
）の需要が著しく増大し、リードフレーム材料の需要も
増加し、諸性能にすぐれたリードフレーム材料の開発が
強く望まれている。(Prior art) Recently, in the electronics field, integrated circuits (ICs)
) has increased significantly, and the demand for lead frame materials has also increased, and there is a strong desire to develop lead frame materials with excellent performance.

一般にこれらリードフレーム材は、帯材とした後、裁断
、打抜き加工を施こし、その表面にＣｕめっき或いはは
んだめっき（浸漬はんだ或いは電気はんだめっき）を施
こし、これにＡｇ、Ａｕ等がめっきされ、さらにシリコ
ンチップを結合（ワイヤーボンディング）してＩＣ素材
として使用される。In general, these lead frame materials are made into strips, then cut and punched, and then Cu plating or solder plating (immersion solder or electric solder plating) is applied to the surface, and then Ag, Au, etc. are plated on this. It is then used as an IC material by bonding silicon chips (wire bonding).

従って、これらリードフレーム材料は、打抜き成形加工
性が良好である事、めっき性がすぐれている事、はんだ
性がすぐれている事が要求される。中でもリードフレー
ムの端子部がＩＣ基盤等にはんだづけされるために、す
ぐれたはんだ性を有することが重要である。Therefore, these lead frame materials are required to have good punching and forming processability, excellent plating properties, and excellent solderability. In particular, since the terminal portion of the lead frame is soldered to an IC board or the like, it is important to have excellent solderability.

さらには素材は、上記のようなめっき等が行なわれる以
前の貯蔵時の耐錆性、さらには処理が行なわれた後の製
品の耐錆性がすぐれている事も要求される。Furthermore, the material is required to have excellent rust resistance during storage before being subjected to the above-mentioned plating, etc., and furthermore, the product is required to have excellent rust resistance after the treatment.

（発明が解決しようとする問題点） 従来、リードフレーム材料としては、強度と熱膨張特性
からＦｅ−４２％Ｎｉ合金が主として使用されており、
またコストと導電性の利点から銅合金も使用されている
。しかしこの銅合金も、導電性及び熱放散性の点では優
れているが、Ｆｅ−４２％Ｎｉ合金に比べ強度が不足す
るため、ＩＣの自動組立工程においてアウターリードを
部材に差込む際折れ曲がるという不都合があった。(Problems to be Solved by the Invention) Conventionally, Fe-42%Ni alloy has been mainly used as a lead frame material due to its strength and thermal expansion characteristics.
Copper alloys are also used due to their cost and conductivity advantages. However, although this copper alloy has excellent conductivity and heat dissipation, it lacks strength compared to Fe-42%Ni alloy, so it has been reported that outer leads may bend when inserted into components during the automatic IC assembly process. There was an inconvenience.

さらには、最近ＩＣの小型化の点から、リードフレーム
素材も極薄化の傾向にあり、高い強度が要求されている
。Furthermore, in view of the recent miniaturization of ICs, lead frame materials are also becoming extremely thin, and high strength is required.

コストの点からは低炭素鋼が最も有効であるが、錆を発
生し易い問題から使用することができない。Low carbon steel is the most effective in terms of cost, but cannot be used because it is susceptible to rust.

一方耐食性及び強度に優れたステンレス鋼は、多量のＣ
ｒを含有するためにめっき性及びはんだ性に問題がある
。このような問題を改善するリードフレーム用素材とし
ては、例えば特開昭５７−５０４５７号、特開昭５９−
９１４９号、特開昭６０−１０３１５８号等の各公報で
紹介されている。これらは基本成分として４〜１１％の
Ｃｒを含有し、その他にＮｉ、　Ｍｏ。On the other hand, stainless steel, which has excellent corrosion resistance and strength, contains a large amount of C.
Since it contains r, there are problems with plating and solderability. Examples of materials for lead frames that can improve this problem include Japanese Patent Application Laid-open No. 57-50457 and Japanese Patent Application Laid-Open No. 59-1989.
It is introduced in various publications such as No. 9149 and Japanese Patent Application Laid-open No. 103158/1983. These contain 4 to 11% Cr as a basic component, as well as Ni and Mo.

Ｃｕ、　ＴＬ　Ｎｂ＋　Ｌ　Ｚｒ等を数％以下含有せし
めてリードフレーム用素材に必要な耐錆性を向上せしめ
、またステンレス鋼の欠点とするめっき性、はんだ性を
改善せしめたリードフレーム用素材である。This is a lead frame material that contains Cu, TL Nb + L Zr, etc. in a few percent or less to improve the rust resistance required for lead frame materials, and also improves the plating and solderability, which are disadvantages of stainless steel. .

これら素材は、それなりの性能向上効果が得られるもの
の必ずしもリードフレーム用素材として充分な性能が得
られていない。すなわち、。Ｃｕめっきのめっき密着性
が充分でなく、特にワイヤーボンディング時の加熱工程
において、Ｃｕめっき層にブリスター（めっき層の部分
的な膨れ）を発生する欠点がみられた。またエレクトロ
ニクス分野で多く使用されるＣ２−イオンのようなハロ
ゲンイオンを含有しないノンハロゲンタイプのフラック
スを用いたはんだづけ作業において、はんだが充分に付
かない問題があった。Although these materials can provide a certain performance improvement effect, they do not necessarily provide sufficient performance as materials for lead frames. In other words. The plating adhesion of the Cu plating was insufficient, and there was a drawback that blisters (partial swelling of the plating layer) occurred in the Cu plating layer, especially during the heating process during wire bonding. Further, in soldering work using a non-halogen type flux that does not contain halogen ions such as C2- ions, which is often used in the electronics field, there is a problem that the solder does not adhere sufficiently.

さらにまた、上記した公知の鋼成分の鋼板に、Ｎｉ或い
はＮｉ合金めっき、またはＣｕ或いはＣｕ合金のめっき
を施こしたリードフレーム用素材が特開昭６１−２８４
９４８号公報で紹介されている。該素材はＦｅ−Ｃｒ系
合金鋼板、すなわち重量％でＣｒ　；　５．０〜１０．
５％、　　Ｃ；　０．１０％以下、Ｓｉ；２．０％以下
、　Ｍｎ；　２．０％以下、　／ｌ　；０．１０％以下
の基本成分の他に、必要に応じてＮｊ；３．０％以下、
　Ｃｕ；　２．０％以下、　Ｍ。Furthermore, a lead frame material obtained by applying Ni or Ni alloy plating, or Cu or Cu alloy plating to a steel plate having the above-mentioned known steel components is disclosed in Japanese Patent Application Laid-Open No. 61-284.
It is introduced in Publication No. 948. The material is a Fe-Cr alloy steel plate, ie, Cr in weight%; 5.0 to 10.
In addition to the basic components: 5%, C: 0.10% or less, Si: 2.0% or less, Mn: 2.0% or less, /l: 0.10% or less, Nj; 3. 0% or less,
Cu; 2.0% or less, M.

；４．０％以下のうち１種又は２種以上、或いはＮｂ。; 4.0% or less of one or more of these, or Nb.

Ｔｉ、　Ｔａ、　Ｚｒのうち１種又は２種以上を０．６
％以下添加し、残部実質的にＦｅよりなる鋼板に、Ｎｉ
或いはＮｉ合金のめっき、またはＣｕ或いはＣｕ合金め
っきの３〜５μの被覆層を施こし、冷間圧延した鋼板で
ある。0.6 of one or more of Ti, Ta, and Zr
% or less, and the remainder is substantially made of Fe.
Alternatively, it is a cold-rolled steel plate coated with a coating layer of 3 to 5 μm of Ni alloy plating, Cu, or Cu alloy plating.

該鋼板は、冷間圧延されたまま或いは歪み取り焼鈍をし
、リードフレーム用素材として使用されるが、Ａｕ又は
Ａｇのめっき性或いはばんだづけ性が、Ｆｅ　−Ｃｒ系
ベース材のまま使用される場合に比してかなり改善され
る。The steel plate is used as a material for lead frames either as cold rolled or after being annealed to remove strain. This is considerably improved compared to the case where

しかしながら該鋼板は、めっき後の冷間圧延時にめっき
金属が圧延ロールに付着するため、外観の平滑良好な製
品を得るのに煩雑な手入れを要するなど、製造面で問題
が多い。However, this steel plate has many problems in terms of manufacturing, such as the fact that the plated metal adheres to the rolling roll during cold rolling after plating, requiring complicated maintenance to obtain a product with a smooth appearance.

また、性能面に対しても、次の様な問題点がある。すな
わちＮｉ或いはＮｉ合金めっき層を施こした素材はめっ
き性或いははんだ性が向上するものの、浸漬はんだを行
なった場合、はんだ組成中のＳｎ金属とＮｉ金属が拡散
反応を生じ、硬くて詭いＮｉ−３ｎ系合金を生成する。Furthermore, in terms of performance, there are the following problems. In other words, materials coated with a Ni or Ni alloy plating layer have improved plating and solderability, but when immersion soldering is performed, a diffusion reaction occurs between the Sn metal and the Ni metal in the solder composition, resulting in a hard and unwieldy Ni metal. -Produces a 3n alloy.

その生成量が多くなると、はんだ層が脆くなって衝撃或
いは曲げ加工を受けた場合に破壊され易い欠点（所謂、
はんだ脆性）がある。特にこの欠点はワイヤーボンディ
ング時に加熱を受けたり、Ｎｉ或いはＮｉ合金のめっき
層が厚くなったりした場合に発生し易い傾向にある。When the amount of solder generated increases, the solder layer becomes brittle and easily breaks when subjected to impact or bending (so-called
(solder brittleness). In particular, this defect tends to occur when the wire is heated during wire bonding or when the plating layer of Ni or Ni alloy becomes thick.

またＣｕ或いはＣｕ合金が施こされた場合には、Ｃｕ或
いはＣｕ合金は、ベースに使用されるＦｅ　−Ｃｒ系組
成の鋼板に比較して著しく責な金属或いは合金であるた
めに、湿潤環境或いはＣ！−イオン等の腐食因子が存在
する腐食環境において、ベースの鋼板が優先腐食され、
赤錆発生成いは穿孔腐食がめつき層のピンホール部或い
は加工時の疵付き部から生じる場合がみられる。この傾
向は、Ｎｉ或いははＮｉ合金のめっき層が施こされる場
合も、Ｆｅ　−Ｃｒ系鋼板の鋼組成によっては同様の原
因による耐食性不良を生じる問題がある。In addition, when Cu or Cu alloy is applied, it is a metal or alloy that is significantly more sensitive than the Fe-Cr based steel sheet used for the base, so it may not be exposed to wet environments or C! - In a corrosive environment where corrosive factors such as ions exist, the base steel plate is preferentially corroded,
Red rust or perforation corrosion may occur from pinholes in the plating layer or from flawed areas during processing. Even when a plating layer of Ni or Ni alloy is applied, this tendency causes a problem of poor corrosion resistance due to the same cause depending on the steel composition of the Fe-Cr steel sheet.

本発明は、上記問題点に鑑みなされたもので、耐食性、
めっき性及びはんだ性にすぐれたリードフレーム用表面
処理鋼板の製造法を提供する。The present invention was made in view of the above problems, and has corrosion resistance,
Provided is a method for manufacturing a surface-treated steel sheet for lead frames with excellent plating and solderability.

（問題点を解決するための手段） 本発明は、重量％で、Ｃ；　０．３０％以下、酸可溶Ａ
Ｎ　；　　０．００５〜０．１０％、　Ｃｒ　；　３〜
１０．５％を含有し、或いはさらにＣｕ　；　０．０５
〜１％、　Ｎｉ　；　０．０５〜３％。(Means for Solving the Problems) The present invention provides, in weight percent, C; 0.30% or less, acid-soluble A;
N: 0.005~0.10%, Cr: 3~
10.5% or further Cu; 0.05
~1%, Ni; 0.05-3%.

Ｍｏ　；　０．０５〜０．５％の１種又は２種以上を含
有し、残部Ｆｅ及び不可避的不純物からなるＣｒ含有Ｉ
ｉＩ板を冷間圧延後、その表面に付着量が１００〜３０
００ｍｇ／ｍ２のＮｉ、　Ｃｏ或いはＮｉとＣｏの合金
の被覆層を設け、次いで非酸化性雰囲気中の４５０℃〜
再結晶温度の温度範囲で１８０秒以下の加熱拡散処理を
施こす耐食性、めっき性及びはんだ性にすぐれたリード
フレーム用表面処理鋼板の製造法である。Mo; Cr-containing I containing 0.05 to 0.5% of one or more kinds, with the balance consisting of Fe and inevitable impurities
After cold rolling the iI plate, the amount of adhesion on its surface is 100 to 30.
A coating layer of 00mg/m2 of Ni, Co, or an alloy of Ni and Co is provided, and then heated at 450°C in a non-oxidizing atmosphere.
This is a method for producing a surface-treated steel sheet for lead frames that has excellent corrosion resistance, plating properties, and solderability, by performing a heat diffusion treatment in the recrystallization temperature range for 180 seconds or less.

以上の如く本発明は、冷間圧延後の前記組成の鋼板表面
に、適正厚さのＮｉ、　Ｃｏ或いはＮｉ　−Ｃｏ合金の
被覆層を施こし、加熱拡散処理を施こすものである。As described above, in the present invention, a coating layer of Ni, Co, or Ni--Co alloy is applied to the surface of a cold-rolled steel sheet having the above composition, and the coating layer is then heated and diffused.

被覆処理後加熱拡散処理を行なう事によって、Ｎｉ＋　
Ｃｏ、　Ｎｉ−Ｃｏ合金被覆層と鋼素材の相互拡散によ
りＦｅを含有するＮｉ　−Ｆｅ、　Ｃｏ−Ｆｅ、或いは
（Ｎｉ＋Ｃｏ）−Ｆｅを主体とする拡散層が生成される
、その結果拡散被覆層は、Ｎｉ　−Ｃｏ、　Ｎ１−Ｃｏ
合金の各単独被覆層よりもさらに素地鋼板との電位差が
小さく近接されるため、めっき欠陥部の素地鋼板の腐食
や、赤錆発生を防止する効果を有すると共に、Ｎｉ−Ｆ
ｅ、　Ｃｏ−Ｆｅ、　　（Ｎｉ＋Ｃｏ）　−Ｆｅ拡散合
金層自体の耐食性もすぐれていることから、下地鋼素材
を防食し、耐錆性能を主体とした耐食性が向上する。By performing heating diffusion treatment after coating treatment, Ni+
A diffusion layer mainly composed of Ni-Fe containing Fe, Co-Fe, or (Ni+Co)-Fe is generated by mutual diffusion between the Co, Ni-Co alloy coating layer and the steel material.As a result, the diffusion coating layer is , Ni-Co, N1-Co
Since the potential difference with the base steel plate is smaller than that of each individual coating layer of the alloy, it has the effect of preventing corrosion of the base steel plate in plating defects and the occurrence of red rust.
Since the corrosion resistance of the e, Co--Fe, (Ni+Co) -Fe diffusion alloy layer itself is excellent, it protects the underlying steel material and improves the corrosion resistance mainly in terms of rust resistance.

特に、該拡散処理層は、Ｎｉ−Ｆｅ合金を被覆処理した
鋼板に比べ、耐錆性能を著しく向上させる。In particular, the diffusion treatment layer significantly improves rust resistance compared to a steel plate coated with a Ni-Fe alloy.

また拡散被覆層は、Ｃｒを含有する素地鋼板に比較して
、リードフレーム製造工程においてＣｕめっき等のめっ
き処理に先立って施こされる酸洗浴により容易に活性化
され、さらに拡散条件を適正に選択する事によって、め
っき密着性及び均一被覆性にすぐれためっき性能が得ら
れる。In addition, compared to a base steel sheet containing Cr, the diffusion coating layer is easily activated by the pickling bath applied prior to plating such as Cu plating in the lead frame manufacturing process, and the diffusion coating layer is further activated by the pickling bath applied prior to plating such as Cu plating in the lead frame manufacturing process. Depending on the selection, plating performance with excellent plating adhesion and uniform coverage can be obtained.

さらにこれら拡散合金被覆層は、Ｐｂ　−Ｓｎ組成から
なる浸漬はんだに対して、ハロゲンイオンを含有しない
フラックスを使用しても、はんだ濡れ性、拡がり性がＣ
ｒ含有鋼板に比較して極めてすぐれており、またＦｅが
合金化されているために、Ｎｉ等の単独層に比較してこ
れら拡散被覆層とＳｎとの間に生成される合金層が少な
くなり、さらには長期に経時或いはワイヤーボンディン
グ時に加熱を受けても、その成長が抑制され、はんだ性
が向上する。Furthermore, these diffusion alloy coating layers have low solder wettability and spreadability when used with immersion solder having a Pb-Sn composition even when a flux that does not contain halogen ions is used.
It is extremely superior to R-containing steel sheets, and because it is alloyed with Fe, fewer alloy layers are formed between these diffusion coating layers and Sn compared to single layers such as Ni. Moreover, even if it is heated over a long period of time or during wire bonding, its growth is suppressed and the solderability is improved.

第１図は７％Ｃｒを含有するＰｅ　−Ｃｒ系鋼板にＮｉ
−Ｆｅ系拡散被覆層、及びＮｉめっき層１０００■／ｒ
ｒｒを各々施こした場合のはんだ濡れ性とはんだ付着後
に長期経過時の密着性を対象とする加熱促進試験を行な
った場合のはんだ密着性を評価した一例を示す。Figure 1 shows a Pe-Cr steel plate containing 7% Cr containing Ni.
-Fe-based diffusion coating layer and Ni plating layer 1000■/r
An example of evaluation of solder adhesion in the case where a heating acceleration test was conducted to evaluate the solder wettability when applying rr and the adhesion over a long period of time after solder adhesion is shown below.

以上の如く本発明は、Ｆｅ　−Ｃｒ系合金鋼板に被覆層
を施こす事によって、リードフレーム用素材に要求され
る性能特性、すなわち耐食性、めっき性及びはんだ性に
すぐれた性能特性が得られる事によってなされたもので
ある。As described above, the present invention provides performance characteristics required for lead frame materials, that is, excellent performance characteristics in corrosion resistance, plating performance, and solderability, by applying a coating layer to a Fe-Cr alloy steel plate. This was done by

（作　用） 以下に本発明について詳細に説明する。(for production) The present invention will be explained in detail below.

転炉、電炉等の溶解炉で溶製された溶銅を連続鋳造また
は造塊、分塊法を経てスラブとし、熱間圧延、酸洗、冷
間圧延の工程を経てＣ、０，３０％以下、酸可溶／ｌ　
ｉ　Ｏ，００５〜０．１０％、　Ｃｒ　；　３〜１０．
５％を含有する鋼板を製造する。Molten copper melted in a melting furnace such as a converter or electric furnace is made into a slab through continuous casting, ingot making, or a blooming method, and is then processed into a slab by hot rolling, pickling, and cold rolling to produce C, 0.30%. Below, acid soluble/l
i O, 005-0.10%, Cr; 3-10.
A steel plate containing 5% is produced.

Ｃは機械的強度向上元素として経済的に有利であるが、
含有量が増加しすぎるとＮｉ、　Ｃｏ、　Ｎｉ　−Ｃ。Although C is economically advantageous as an element for improving mechanical strength,
If the content increases too much, Ni, Co, Ni-C.

合金の被覆層のピンホール、被覆層欠陥等を増加し、ま
た加熱拡散処理に対しても均一拡散が損なわれ、耐食性
、リードフレーム製造工程でのめつき性、はんだ性等が
劣化する。すなわち、素地鋼板の表面にセメンタイト或
いはクロムカーバイド等の析出量が多くなり、Ｎｉ、Ｃ
ｏ等の被覆層の均一被覆性とめっき密着性等が劣化し、
また加熱拡散処理に対してはこれらが拡散阻害要因とな
って均一拡散を阻害し、均一な性能をもつ良好な拡散被
覆層が得られない。従って、素地鋼板中のＣ含有量は、
耐食性、均一拡散被覆層の生成の観点から０．３０％以
下、好ましくは０．１θ％以下である。This increases pinholes and defects in the coating layer of the alloy, and also impairs uniform diffusion during heat diffusion treatment, resulting in deterioration of corrosion resistance, plating properties, solderability, etc. in the lead frame manufacturing process. In other words, the amount of precipitation of cementite or chromium carbide on the surface of the base steel sheet increases, and Ni, C
The uniform coverage and plating adhesion of coating layers such as o etc. deteriorate,
Furthermore, in the heat diffusion treatment, these substances act as a diffusion inhibiting factor and inhibit uniform diffusion, making it impossible to obtain a good diffusion coating layer with uniform performance. Therefore, the C content in the base steel plate is
From the viewpoint of corrosion resistance and formation of a uniform diffusion coating layer, the content is 0.30% or less, preferably 0.1θ% or less.

Ａ！は、鋼中に残存する酸可溶Ａ／！（Ｓｏｆ、Ａｊ’
）量が０．００５％未満の少食有量では、酸素性ガスに
よる気泡の発生を防止する事が困難であり、綱の表面欠
陥発生率を著しく高め、鋼素材自体の耐食性劣化、機械
的性質劣化の起点となるので好ましいものでない。０．
１０％を越える過剰な酸可溶Ａｆは、ＡＮ系酸化物を鋼
表面に点在せしめて耐食性劣化の起点となり、さらに被
覆層処理に対して均一被覆性を阻害する要因となり好ま
しいものでない。従って、鋼中に含有される５ｏｆｆｉ
、Ａｊ！は、表面処理鋼板の性能が安定して確保できる
量として０．００５〜０．１０％、好ましくはｏ、ｏｉ
〜０．０８％である。A! is the acid-soluble A/! remaining in the steel. (Sof, Aj'
) If the amount is less than 0.005%, it is difficult to prevent the formation of bubbles due to oxygen gas, which significantly increases the incidence of surface defects in the steel, deteriorates the corrosion resistance of the steel material itself, and deteriorates the mechanical properties. This is not preferable because it becomes a starting point for deterioration. 0.
Excessive acid-soluble Af in excess of 10% is not preferable because it causes AN-based oxides to be scattered on the steel surface, becoming a starting point for deterioration of corrosion resistance, and further inhibiting uniform coverage in coating layer treatment. Therefore, 5offi contained in steel
,Aj! is 0.005 to 0.10% as the amount that can stably ensure the performance of the surface-treated steel sheet, preferably o, oi
~0.08%.

Ｃｒは、本発明においてめっき原板の耐食性と強度を向
上する元素として添加するものである。Ｃｒ含有鋼板は
、Ｃｒ含有なし鋼板に比して、鋼板自体の耐錆性、耐食
性自体がすぐれているとともに、腐食環境においてＮｉ
−Ｆｅ系、Ｃｏ　−Ｆｅ系或いは（Ｎｉ＋Ｃｏ）　−Ｆ
ｅ系の拡散被覆層の電位に近接化される。Cr is added in the present invention as an element that improves the corrosion resistance and strength of the plated original plate. Cr-containing steel sheets have superior rust and corrosion resistance as compared to steel sheets without Cr, and they also have superior Ni resistance in corrosive environments.
-Fe system, Co -Fe system or (Ni+Co) -F
The potential is brought close to that of the e-type diffusion coating layer.

その結果、鋼板自体の耐食性向上効果、被覆層による耐
食性向上効果及び鋼板と被覆層の複合相乗効果などから
すぐれた耐錆性、耐食性が得られる。As a result, excellent rust resistance and corrosion resistance can be obtained from the corrosion resistance improvement effect of the steel plate itself, the corrosion resistance improvement effect of the coating layer, and the combined synergistic effect of the steel plate and the coating layer.

また、鋼中にＣｒを含有することによって、機械的強度
が耐食性と共に併せ得られる。本発明においてＣｒ含有
量が３％未満では、目的とする耐食性、強度が得られな
い。また、Ｃｒ含有量が１０６５％を越える場合は次の
様な欠点を有する。すなわち、拡散処理に先立って施こ
されるＮｉ被覆処理には密着性の良好な被覆層を得るの
に活性化前処理が必要である。また拡散処理後において
も、素地鋼板のＣｒ含有量が増加すると、拡散被覆層表
面にＣｒの拡散量が増加し、その表面Ｃｒを含有するＮ
ｉ　−Ｃｒ−Ｆｅ系、或いはＣｏ　−Ｃｒ　−Ｐｅ系等
の前処理酸洗等による活性化処理が困難な被覆層が形成
され易くなる。Furthermore, by including Cr in the steel, mechanical strength and corrosion resistance can be obtained. In the present invention, if the Cr content is less than 3%, the desired corrosion resistance and strength cannot be obtained. Further, when the Cr content exceeds 1065%, the following drawbacks occur. That is, the Ni coating treatment performed prior to the diffusion treatment requires an activation pretreatment to obtain a coating layer with good adhesion. Furthermore, even after the diffusion treatment, when the Cr content of the base steel sheet increases, the amount of Cr diffused onto the surface of the diffusion coating layer increases, and the N containing Cr on the surface increases.
An i-Cr-Fe based coating layer, a Co-Cr-Pe based coating layer, etc., which is difficult to be activated by pre-treatment pickling, etc., is likely to be formed.

そのために、リードフレーム製造工程で均一被覆性にす
ぐれためっき層或いはめっき密着性の良好なめっき層が
得られにくくなり、はんだ濡れ性、拡がり性等も著しく
劣化してはんだ性能を低下させる。さらには、リードフ
レーム素材に要求される電気伝導性、熱伝導性の点から
も、Ｃｒの含有量が少ない方が好ましい。従ってＣｒ含
有量の範囲は、３〜１０．５％、好ましくは５〜１０％
である。For this reason, it becomes difficult to obtain a plating layer with excellent uniform coverage or a plating layer with good plating adhesion in the lead frame manufacturing process, and solder wettability, spreadability, etc. are significantly deteriorated, resulting in a decrease in solder performance. Furthermore, from the viewpoint of the electrical conductivity and thermal conductivity required for the lead frame material, it is preferable that the Cr content be small. Therefore, the range of Cr content is 3 to 10.5%, preferably 5 to 10%.
It is.

また、めっき原板中の不可避的不純物元素については、
特に規定されるものではないが、以下に述べるような含
有量が好ましい。Regarding unavoidable impurity elements in the plating original plate,
Although not particularly specified, the content as described below is preferable.

Ｓｉは、０．６％以下が好ましい。Ｓｉは機械的強度上
昇に有効であるが、Ｓｉ含有量が過剰に増加すると、Ｓ
ｔ系酸化物が鋼表面に点在し、本発明における合金めっ
き被覆処理に対して、均一被覆性を阻害するので、耐食
性の点で好ましいものでない。The content of Si is preferably 0.6% or less. Si is effective in increasing mechanical strength, but if the Si content increases excessively, S
Since t-based oxides are scattered on the steel surface and impede uniform coating properties in the alloy plating treatment of the present invention, they are not preferred in terms of corrosion resistance.

従って、０．６％以下好ましくは０．１５％以下である
。Therefore, it is 0.6% or less, preferably 0.15% or less.

Ｍｎは、耐食性に悪影響を及ぼすことはないが、含有量
の増加により機械的強度を上昇し圧延加工性を劣化する
ので、１．５％以下がよい。Although Mn does not have an adverse effect on corrosion resistance, an increase in Mn content increases mechanical strength and deteriorates rolling workability, so it is preferably 1.5% or less.

その他、Ｐ、Ｓについては、通常の製鋼方式で含有され
る範囲で０．０２％以下がよい。特に、端面等原板素材
が露出される部分の耐錆性を向上せしめるためには、Ｓ
がｏ、ｏｏｓ％以下が好ましい。In addition, P and S are preferably contained within the range of 0.02% or less in a normal steel manufacturing method. In particular, in order to improve the rust resistance of parts such as end faces where the original plate material is exposed, S
is preferably less than o, oos%.

さらに、第２の本発明においては、上記の成分で構成さ
れるめっき原板にＣ（１＋Ｎｔ＋Ｍｏの１種又は２種以
上を含有せしめる。これら元素は、鋼板自体の耐錆性、
耐食性を向上するとともに、腐食環境においては前記し
たようにＣｒとの複合添加によって電位が貴（カソーデ
イック）になり、拡散被覆層との電位差が近接化され、
Ｆｅの優先腐食による耐錆性、耐食性能の劣化が一段と
防止される。Furthermore, in the second aspect of the present invention, the plated base plate composed of the above components is made to contain one or more of C(1+Nt+Mo).These elements are used to improve the rust resistance of the steel plate itself,
In addition to improving corrosion resistance, in a corrosive environment, the potential becomes noble (cathodic) due to the composite addition with Cr, and the potential difference with the diffusion coating layer is brought closer.
Deterioration of rust resistance and corrosion resistance due to preferential corrosion of Fe is further prevented.

而して、これら元素の添加は、Ｃｕが０．０５〜１．０
％、Ｎｉが０．０５〜３．０％、ＭＯが０．０５〜０．
５％である。Therefore, the addition of these elements is such that Cu is 0.05 to 1.0
%, Ni 0.05-3.0%, MO 0.05-0.
It is 5%.

Ｃｕの添加量が０．０５％未満では、上記の耐食性効果
が得られず、また１、０％を越える場合は原板製造時の
熱延工程において赤錆脆性による割れや鋼表面にＣｕが
濃縮し、スケール疵を発生し易くなる。If the amount of Cu added is less than 0.05%, the above-mentioned corrosion resistance effect cannot be obtained, and if it exceeds 1.0%, Cu may cause cracking due to red rust brittleness or concentrate on the steel surface during the hot rolling process during the production of the original sheet. , scale defects are more likely to occur.

従って、Ｃｕは０．０５〜１．０％、好ましくは０．１
〜０．５％である。Therefore, Cu is 0.05 to 1.0%, preferably 0.1%
~0.5%.

Ｎｉは、添加量が０．０５％未満では、耐食性効果が得
られず、また、３．０％を越える場合は、耐食性の向上
効果が飽和するとともに、Ｃｒとの共存効果によって被
覆層のすぐれた密着性を得るための鋼表面の前処理作業
が煩雑となる。従ってその添加量は０．０５〜３．０％
、好ましくは０．１〜１．５％である。If the amount of Ni added is less than 0.05%, no corrosion resistance effect will be obtained, and if it exceeds 3.0%, the corrosion resistance improvement effect will be saturated, and the coexistence effect with Cr will reduce the quality of the coating layer. Pretreatment of the steel surface to obtain good adhesion becomes complicated. Therefore, the amount added is 0.05 to 3.0%
, preferably 0.1 to 1.5%.

Ｍｏの添加量が０．０５％未満では、耐食性向上効果が
得られず、また０、５％を越える場合はその効果が飽和
するとともに、材質が硬質化し、リードフレームのよう
な薄手材を得るための圧延加工が困難となる。従って、
その添加量は０．０５〜０．５０％、好ましくは０．１
〜０．３％である。If the amount of Mo added is less than 0.05%, the effect of improving corrosion resistance cannot be obtained, and if it exceeds 0.5%, the effect is saturated and the material becomes hard, resulting in a thin material such as a lead frame. This makes rolling processing difficult. Therefore,
The amount added is 0.05-0.50%, preferably 0.1%
~0.3%.

さらに上記のような成分組成の鋼板（めっき原板）をそ
のまま使用したのでは、耐錆性等の耐食性、リードフレ
ーム製造工程でＣｕ、Ｐｂ　−３ｎ合金等のめっき性、
或いははんだ性がリードフレーム用素材として不充分で
あり、従ってＮｉ−Ｆｅ系、Ｃｏ　−Ｆｅ系或いは（Ｎ
ｉ＋Ｃｏ）　−Ｆｅ系の拡散被覆層が設けられる。Furthermore, if a steel plate (plated original plate) with the above-mentioned composition is used as is, corrosion resistance such as rust resistance, plating properties such as Cu and Pb-3n alloy, etc. in the lead frame manufacturing process,
Or, the solderability is insufficient as a lead frame material, so Ni-Fe, Co-Fe, or (N
i+Co) -Fe-based diffusion coating layer is provided.

本発明においては冷間圧延後の上記素地鋼板に対して、
所定の厚さのＮｉ、Ｃｏ、Ｎｉ−Ｃｏ合金が被覆される
。この被覆処理に先立ち、素材表面は先ず浸漬或いは電
解等の方法による脱脂及び酸溶液を用いた活性化処理が
行なわれる。この活性化処理には、浸漬、スプレィ等に
よる酸洗処理或いは電解酸洗処理が行なわれるが、Ｃｒ
含有鋼板特有の表面の酸化膜の除去、還元を均一に行な
うためには、電解酸洗処理が望ましい。In the present invention, for the base steel plate after cold rolling,
A predetermined thickness of Ni, Co, and Ni-Co alloy is coated. Prior to this coating treatment, the surface of the material is first degreased by a method such as immersion or electrolysis, and activated using an acid solution. This activation treatment includes pickling treatment by dipping, spraying, etc., or electrolytic pickling treatment, but Cr
Electrolytic pickling treatment is desirable in order to uniformly remove and reduce the oxide film on the surface peculiar to steel sheets containing steel.

すなわち、酸洗浴中での鋼素材を陰極にした陰極電解酸
洗の酸化膜還元による活性化処理、鋼素材を陽極にした
陽極電解酸洗の酸化膜溶解除去による活性化処理、或い
は陽極電解により酸化膜溶解除去後更に陰極電解によっ
て表面の活性化処理を組み合わせた方法等が採用される
。That is, activation treatment by reducing the oxide film by cathodic electrolytic pickling using the steel material as the cathode in a pickling bath, activation treatment by dissolving and removing the oxide film by anodic electrolytic pickling using the steel material as the anode, or activation treatment by anodic electrolysis. After dissolving and removing the oxide film, a method is employed in which the surface is further activated by cathodic electrolysis.

これらのうち、特に陽極電解処理後にさらに陰極電解処
理を組み合わせる方法が、Ｃｒ含有鋼特有の焼鈍過程等
において形成された強固な酸化被膜を除去、還元せしめ
て、表面を活性化するのに好ましい。これらの電解酸洗
を行なう方法としては、例えばＨ２ＳＯ，浴、ＨｇＳＯ
４浴にＦ−イオンを含有せしめた浴等を用い、電流密度
１０〜６０Ａ／ｄｍ”　、温度が常温〜８０℃、電解時
間０．５〜１０秒の範囲がよい。Among these, a method in which cathodic electrolytic treatment is further performed after anodic electrolytic treatment is particularly preferable for removing and reducing the strong oxide film formed during the annealing process peculiar to Cr-containing steel and activating the surface. These electrolytic pickling methods include, for example, H2SO, bath, HgSO
It is preferable to use a bath containing F- ions, etc., with a current density of 10 to 60 A/dm'', a temperature of room temperature to 80 DEG C., and an electrolysis time of 0.5 to 10 seconds.

続いて行なわれるＮｉ、Ｃｏ、Ｎｉ　−Ｃｏ合金の被覆
処理方法については、例えば次のような条件の電気めっ
き法によって被覆処理を行うとよい。−（ａ）Ｎｉめっ
き めっき浴組成の一例 硫酸ニッケル　　　　　２４０ｇ／ｊ！塩化ニッケル　
　　　　　４５　ｇ／ｌホウ酸　　　　　　　　　４０
　ｇ＃！電流密度　　　　　　　　　７．５Ａ／ｄｎ＋
”めっき浴温　　　　　　　　４０°Ｃ （ｂ）Ｃｏめっき めっき浴組成の一例 硫酸コバルト　　　　　　７５　ｇ／ｌ塩化コバルト　
　　　　１４０　ｇ／ｌホウ酸　　　　　　　　　２５
ｇ／ｌ 電流密度　　　　　　　　　５０Ａ／ｄｍ”めっき浴温
　　　　　　　　５５℃ （Ｃ）Ｎｉ　−Ｃｏ合金めっき めっき浴組成の一例 硫酸ニッケル　　　　　　５０　ｇｅｌ硫酸コバルト　
　　　　　２５　ｇ／ｌ塩化ニッケル　　　　　１００
　ｇ／ｌ塩化コバルト　　　　　　５０　ｇｅｌホウ酸
　　　　　　　　　３０　ｇ／Ｉｌ電流密度　　　　　
　　　　３０Ａ／ｄａ”めっき浴温　　　　　　　　６
５°Ｃ の如き条件で電気めっき法による被覆処理を行なう。Regarding the subsequent coating treatment method of Ni, Co, and Ni--Co alloy, it is preferable to perform the coating treatment by, for example, an electroplating method under the following conditions. -(a) Ni plating Example of plating bath composition Nickel sulfate 240g/j! nickel chloride
45 g/l boric acid 40
g#! Current density 7.5A/dn+
”Plating bath temperature 40°C (b) Co plating Example of plating bath composition Cobalt sulfate 75 g/l Cobalt chloride
140 g/l boric acid 25
g/l Current density 50A/dm Plating bath temperature 55℃ (C) Ni-Co alloy plating An example of plating bath composition Nickel sulfate 50 gel Cobalt sulfate
25 g/l nickel chloride 100
g/l cobalt chloride 50 gel boric acid 30 g/Il current density
30A/da” plating bath temperature 6
The coating treatment is carried out by electroplating under conditions such as 5°C.

次いで本発明においては、リードフレーム用素材に要求
される機械的性質を確保し、耐食性、リードフレーム製
造工程でのめっき性或いははんだ性にすぐれた性能を有
する拡散被覆層を得るための加熱拡散処理が行なわれる
。Next, in the present invention, a heating diffusion treatment is performed to obtain a diffusion coating layer that secures the mechanical properties required for the lead frame material and has excellent corrosion resistance and excellent plating and solderability in the lead frame manufacturing process. will be carried out.

すなわち上記成分の素地鋼板を冷間圧延後、脱脂、酸洗
等の前処理、活性化処理を施こした後、１００〜３００
０ｍｇ／ｍ２の範囲の付着量（片面当り）のＮｘｔＣｏ
＋Ｎｓ　　Ｃｏ合金の被覆処理を行ない、次いで４５０
゛Ｃより高温でかつ再結晶温度より低い温度非酸化性雰
囲気中で１８０秒以下加熱処理を施こす。That is, after cold-rolling a base steel sheet with the above components and subjecting it to pretreatment such as degreasing and pickling, and activation treatment,
NxtCo with a coating amount (per one side) in the range of 0 mg/m2
+Ns Co alloy coating treatment, then 450
Heat treatment is performed for 180 seconds or less in a non-oxidizing atmosphere at a temperature higher than C and lower than the recrystallization temperature.

このような被覆層を施こす事によって、加熱時に鋼板の
酸化が防止される。その結果として、加熱雰囲気、加熱
時間等の点で加熱処理が鋼板のままに比して、有利とな
る。By applying such a coating layer, oxidation of the steel plate is prevented during heating. As a result, heat treatment is more advantageous than treating the steel plate as is in terms of heating atmosphere, heating time, etc.

このような処理により、高強度材質でかつ曲げ加工性に
必要な延性を有し、さらに素材鋼板と拡散被覆層との複
合効果によって、耐錆性を中心とした耐食性、めっき性
、はんだ性能の向上が可能なリードフレーム用素材を効
率よく製造する事が可能となる。Through this treatment, the material has high strength and ductility necessary for bending workability, and the combined effect of the material steel plate and the diffusion coating layer improves corrosion resistance, mainly rust resistance, plating performance, and solder performance. It becomes possible to efficiently manufacture materials for lead frames that can be improved.

この加熱条件′は、性能にすぐれた拡散被覆層を得るた
めには、Ｎｉ、Ｃｏ、Ｎｉ−Ｃｏ合金の被覆層量の規制
が重要である。すなわちこれらの被覆層量が１００ｍｇ
／ｍ２未満の場合では、被覆層のピンホール等の被膜欠
陥が多く生成されるため、加熱拡散処理後も均一な拡散
被覆層が生成され難く、加熱処理時に欠陥部からの素材
鋼板の酸化も生じ易い。Regarding this heating condition, in order to obtain a diffusion coating layer with excellent performance, it is important to control the amount of coating layer of Ni, Co, and Ni--Co alloy. That is, the amount of these coating layers is 100 mg
/m2, many coating defects such as pinholes are generated in the coating layer, making it difficult to produce a uniform diffusion coating layer even after heat diffusion treatment, and oxidation of the raw steel sheet from defective areas during heat treatment. Easy to occur.

そのため素材鋼板の露出部分の面積の増加等によって、
耐食性向上効果、めっき性或いははんだ性の向上効果が
得られにくい。Therefore, due to an increase in the area of the exposed part of the material steel plate, etc.
It is difficult to obtain the effect of improving corrosion resistance, plating property, or solderability.

また、その被覆層量が３０００ｍｇ／％を越える場合は
、これらの被膜を設けた後加熱拡散処理を施こした素材
の耐食性、めっき性、はんだ性等の向上効果が飽和する
とともに、剪断加工等の加工を受けた場合に、被膜にク
ラックが生成されたり、或いは部分的な剥離を生じる現
象が起こる。In addition, if the amount of the coating layer exceeds 3000 mg/%, the effects of improving corrosion resistance, plating properties, solderability, etc. of the material subjected to heat diffusion treatment after providing the coating will be saturated, and the shearing process etc. When subjected to such processing, cracks are generated in the coating, or phenomena such as partial peeling occur.

さらに被膜量が上記のように多くなると、充分に拡散処
理が行なわれ難く、各々表面拡散被覆層にＮｉ、Ｃｏ或
いはＮ１ａＣｏのＦｅに対する含有比率の大なる例えば
各々の濃度が９０％をこえるような拡散被覆層が形成さ
れる。その結果として被膜自体の耐食性、はんだ濡れ性
等の向上効果は得られるものの、Ｎｉ、Ｃｏ等が多くな
ると電位が責な方向に移行するため、原板素材との電位
差が拡大し、被膜欠陥部等から原板素材の優先腐食によ
る赤錆発生が生じ易くなり、耐食性を劣化する傾向にな
る。Furthermore, when the amount of the coating increases as described above, it is difficult to perform the diffusion treatment sufficiently, and if the surface diffusion coating layer has a large content ratio of Ni, Co, or N1aCo to Fe, for example, the concentration of each exceeds 90%. A diffusion coating layer is formed. As a result, the corrosion resistance and solder wettability of the coating itself can be improved, but as the amount of Ni, Co, etc. increases, the potential shifts in a negative direction, so the potential difference with the original plate material increases, causing defects in the coating, etc. Therefore, red rust is likely to occur due to preferential corrosion of the original plate material, and corrosion resistance tends to deteriorate.

また、Ｎｉ、Ｃｏは安定した緻密な酸化膜を生成するた
め、これらの含有率が大なる拡散被覆層は、リードフレ
ーム製造工程でのめっき（Ｃｕ或いはｐｂ−Ｓｎ電気は
んだめっき等）に先立つ酸洗活性化処理を困難にする傾
向があるので、均一なめっき被覆性及びめっき密着性を
得るためには好ましいものではない。Furthermore, since Ni and Co form a stable and dense oxide film, a diffusion coating layer with a large content of Ni and Co should be treated with acid prior to plating (Cu or PB-Sn electric solder plating, etc.) in the lead frame manufacturing process. Since it tends to make washing and activation treatment difficult, it is not preferable for obtaining uniform plating coverage and plating adhesion.

さらに最も重要な問題は、Ｆｅに対する拡散合金化元素
が高濃度の場合（例えば９０％を越えた場合）には、溶
融Ｐｂ　−Ｓｎはんだの濡れ性、拡がり性等の効果が飽
和するとともに、はんだ中のＳｎ金属とこれら合金化元
素との反応或いは拡散によるＮｉ−５ｎ、　Ｃｏ−５ｎ
合金の生成量が多くなり、これらの硬くて脆い合金層の
生成によってはんだづけ部が衝撃或いは曲げ加工等を受
けた場合に破壊され易すくなる。従って、はんだ脆性防
止の観点から、加熱処理に先立って施こされるＮｉ、Ｇ
ｏ、　ＮｉとＣｏの　□合金の被覆層量は３０００ｍｇ
／ｍ２以下とした。従って加熱拡散処理に先立ちＮｔ＋
Ｃｏ或いはＮｉとＣｏの合金の被覆層量は、１００〜３
０００■／ホ、好ましくは３００〜２０００ｍｇ／ｍ２
である。Furthermore, the most important problem is that when the concentration of diffusion alloying elements for Fe is high (for example, exceeding 90%), the wettability, spreadability, etc. effects of molten Pb-Sn solder are saturated, and the solder Ni-5n, Co-5n due to the reaction or diffusion between the Sn metal inside and these alloying elements
The amount of alloy produced increases, and the formation of these hard and brittle alloy layers makes the soldered part more likely to break when subjected to impact, bending, or the like. Therefore, from the viewpoint of preventing solder embrittlement, Ni and G are applied prior to heat treatment.
o, The amount of coating layer of □ alloy of Ni and Co is 3000mg
/m2 or less. Therefore, before heating and diffusion treatment, Nt+
The amount of coating layer of Co or alloy of Ni and Co is 100 to 3
000■/E, preferably 300-2000mg/m2
It is.

次いでリードフレーム用素材に要求される機械的性質及
び必要性能（耐食性、リードフレーム工程でのめっき性
、はんだ性）を得るために加熱処理が施こされる。加熱
処理条件は次のような理由から規制される。すなわち、
鋼成分の素地鋼板を冷間圧延後、脱脂、酸洗の前処理・
活性化処理後Ｎｉ等の被覆層を設け、加熱処理が施こさ
れる。Next, heat treatment is performed to obtain the mechanical properties and required performance (corrosion resistance, plating properties in the lead frame process, solderability) required for the lead frame material. Heat treatment conditions are regulated for the following reasons. That is,
After cold-rolling the base steel sheet, pre-treatments such as degreasing and pickling are applied.
After the activation treatment, a coating layer of Ni or the like is provided, and a heat treatment is performed.

リードフレーム用素材に要求される機械的性質は、リー
ドフレーム形状への打抜き成形加工性を考慮した場合、
延性の少ない高強度材がすぐれており、またリードフレ
ーム製品には強度と同時に、折れ曲げ加工性が要求され
る。The mechanical properties required for the lead frame material are as follows, considering the punching processability into the lead frame shape.
High-strength materials with low ductility are excellent, and lead frame products require both strength and bending workability.

これらの観点から種々検討した結果、強度は４５〜８５
ｋｇ／ｍｍ”好ましくは５５〜８０ｋｇ／ＩＩＩＩＩｌ
！、伸びは３〜２０％好ましくは５〜１５％の機械的性
質のものが良好である。すなわち、強度が４５ｋｇ／ｍ
ｍ”未満の場合は、素材の硬度が低く、軟質のために、
打抜き成形機のポンチ或いはダイスからの加工材の抜は
性が悪く、打抜き成形速度に悪影響を及ぼす。また強度
が８５ｋｇ／＋ｕ”を越える場合は、素材の硬度が高く
なり、打抜き成形時、素材に割れを発生し、成形機のポ
ンチ、ダイスに損耗が生じ易くなる。従って、素材の強
度は４５〜８５ｋｇ／ｌｌｌｌ１１２、好ましくは５５
〜８０ｋｇ／ｍｎ＋”である。As a result of various studies from these points of view, the strength was 45 to 85.
kg/mm” preferably 55 to 80 kg/III
! Good mechanical properties include elongation of 3 to 20%, preferably 5 to 15%. That is, the strength is 45 kg/m
If it is less than m”, the hardness of the material is low and it is soft.
The punch or die of a punching machine has poor punching properties, which adversely affects the punching speed. If the strength exceeds 85 kg/+u", the hardness of the material will increase, causing cracks in the material during punching and forming, and wear and tear on the punches and dies of the forming machine. Therefore, the strength of the material will be 45 kg/+u". ~85kg/llll112, preferably 55
〜80kg/mn+''.

またリードフレーム製品は、曲げ加工された足部分の強
度と同時に、曲げ加工時の繰り返し曲げ加工に充分たえ
ることが必要である。従って、素材の伸び率が３％未満
の場合は、折り曲げ加工によって素材の割れが発生する
。また伸び率が２０％を越える場合は、曲げ加工性は良
好であるが、高強度が得られ難く、リードフレーム製品
の強度が不足するとともに、又打抜き成形性に対しても
好ましくない。従って、伸びは３％〜２０％、好ましく
は５〜１５％である。In addition, the lead frame product needs to have sufficient strength in the bent leg portion and to withstand repeated bending during bending. Therefore, if the elongation rate of the material is less than 3%, the material will crack during bending. If the elongation exceeds 20%, bending workability is good, but it is difficult to obtain high strength, resulting in insufficient strength of the lead frame product and also being unfavorable for punching formability. Therefore, the elongation is between 3% and 20%, preferably between 5 and 15%.

而して、本発明に使用される鋼成分の素材に被覆層を設
けた素材を用いて、これらの機械的性質を確保するとと
もに、リードフレーム用素材に要求される耐食性、めっ
き性或いははんだ性の優れた性能を得る事が可能な製造
方法として加熱拡散処理を行なう。Therefore, by using a material in which a coating layer is provided on the steel component material used in the present invention, these mechanical properties are ensured, and the corrosion resistance, plating properties, and solderability required for lead frame materials are achieved. Thermal diffusion treatment is performed as a manufacturing method that can obtain excellent performance.

リードフレーム用素材として上記の機械的性質及び各種
性能を向上せしめるためには、加熱温度４５０℃以上で
かつ再結晶温度より低い温度で加熱処理温度と拡散処理
を同時に、非酸化性雰囲気において、保定時間１８０秒
以下の加熱処理を行なう。In order to improve the above-mentioned mechanical properties and various performances as a material for lead frames, it is necessary to simultaneously perform heat treatment and diffusion treatment at a heating temperature of 450°C or higher and lower than the recrystallization temperature, and to hold the material in a non-oxidizing atmosphere. Heat treatment is performed for a time of 180 seconds or less.

加熱温度が４５０°Ｃより低い温度で、かつ保定時間１
８０秒以下の加熱処理では、曲げ加工に耐える機械的性
質を得るのに素地鋼板の成分が限定される問題があり、
Ｎｉ、Ｃｏ等の被覆層の拡散処理が充分に行なわれ難い
問題がある。従って前記した素材鋼成分の全組成範囲に
亙ってリードフレーム用素材として好ましい機械的性質
を得るのが困難である。また拡散被覆層はＮｉ、Ｃｏ等
の濃度の大なる被覆層或いは表面はＮｉ、Ｃｏ層のまま
残存するために、耐食性、或いはリードフレーム製造工
程でのめっき性、はんだ脆性等の点で本発明の目的とす
る効果が得られない。The heating temperature is lower than 450°C and the retention time is 1.
Heat treatment for 80 seconds or less has the problem that the composition of the base steel sheet is limited in order to obtain mechanical properties that can withstand bending.
There is a problem in that it is difficult to sufficiently diffuse the Ni, Co, etc. coating layer. Therefore, it is difficult to obtain desirable mechanical properties as a lead frame material over the entire composition range of the steel material components described above. In addition, since the diffusion coating layer has a high concentration of Ni, Co, etc., or the surface remains as a Ni, Co layer, the present invention has improved corrosion resistance, plating properties in the lead frame manufacturing process, solder brittleness, etc. The desired effect cannot be obtained.

加熱温度が再結晶温度を越える場合には、素地鋼板の強
度が軟質化して上記の目的とする機械的強度が得られに
くい。さらに加熱温度が高温になるとＣｒの拡散量が多
くなり、また加熱処理を非酸化性雰囲気といえども拡散
被覆層表面が高温のため酸化され、緻密で強固な酸化膜
が生成して、リードフレーム製造工程のめっき性、はん
だ性を阻害する。従ってこれらの観点から、加熱温度は
４５０℃より高い温度で、かつ再結晶温度より低い温度
の範囲が採用される。尚素地鋼板の再結晶温度は、鋼成
分及び圧下率の程度によって若干のばらつきがあるが、
概そ５８０°Ｃ程度であり、本発明では４７５℃〜５５
０°Ｃの範囲で加熱処理が施こされるのが好ましい。When the heating temperature exceeds the recrystallization temperature, the strength of the base steel sheet becomes soft, making it difficult to obtain the desired mechanical strength. Furthermore, when the heating temperature becomes high, the amount of Cr diffused increases, and even if the heat treatment is performed in a non-oxidizing atmosphere, the surface of the diffusion coating layer is oxidized due to the high temperature, forming a dense and strong oxide film, which leads to the formation of a lead frame. Impairs plating and solderability in the manufacturing process. Therefore, from these viewpoints, the heating temperature is higher than 450° C. and lower than the recrystallization temperature. The recrystallization temperature of the base steel sheet varies slightly depending on the steel composition and degree of reduction, but
The temperature is approximately 580°C, and in the present invention, the temperature is 475°C to 55°C.
Preferably, the heat treatment is performed in the range of 0°C.

また、加熱時間が１８０秒を越える場合は、上記の加熱
温度の範囲での処理によって素地鋼板からの被覆層への
拡散によるＦｅ以外にＣｒ等の添加元素の拡散量が多く
なり、前記した如く加熱雰囲気の調整を可成り厳格に行
なっても、拡散層表面に強固で緻密な酸化膜が生成され
易すくなる。その結果として、リードフレーム製造工程
でのめっき作業において、前処理・活性化処理が極めて
困難となり、均一被覆性とめっき密着性のすぐれたＣｕ
めっき或いは電気Ｐｂ−５ｎはんだめっき等を得るのが
難しくなり、また浸漬はんだに対してその濡れ性、はん
だ拡がり性を劣化する。In addition, if the heating time exceeds 180 seconds, the amount of diffusion of additional elements such as Cr in addition to Fe due to diffusion from the base steel sheet to the coating layer increases due to the treatment within the above heating temperature range, as described above. Even if the heating atmosphere is adjusted quite strictly, a strong and dense oxide film is likely to be formed on the surface of the diffusion layer. As a result, pretreatment and activation treatments are extremely difficult in the plating work in the lead frame manufacturing process, and Cu, which has excellent uniform coverage and plating adhesion,
It becomes difficult to obtain plating or electric Pb-5n solder plating, and the wettability and solder spreadability of immersion solder deteriorates.

また、保定時間の下限は特に規定しないが、拡散処理を
均一に行なわしめるために１０秒以上、好ましくは２０
秒以上がよい。さらに、このような加熱処理の加熱雰囲
気は、非酸化性雰囲気が採用され、Ｎ２ガス、アン干ニ
ア分解ガス（ＡＸガス）、５％Ｈ２−Ｎ、系ＭｉＸガス
が用いられる。In addition, the lower limit of the retention time is not particularly specified, but in order to perform the diffusion treatment uniformly, it is 10 seconds or more, preferably 20 seconds or more.
Seconds or more is better. Furthermore, a non-oxidizing atmosphere is employed as the heating atmosphere for such heat treatment, and N2 gas, annealed carbon decomposition gas (AX gas), 5% H2-N, and MiX-based gas are used.

尚加熱処理を行なった後、形状修正のための軽圧下処理
を施こしてもよく、またＮｉ等の被覆処理を施こす過程
において、めっき浴或いは電極等から不可避的に含有さ
れる不純物、例えばＳ、　Ｂ等が少量（約１％未満）含
有されても、本発明に支障をきたすものではない。After the heat treatment, a light pressure treatment may be performed to modify the shape, and in the process of coating with Ni etc., impurities unavoidably contained from the plating bath or electrodes, such as Even if a small amount (less than about 1%) of S, B, etc. is contained, the present invention will not be affected.

以上の如く鋼成分にＮｔ、　Ｃｏ等の被覆層を設け、前
記の加熱処理方法で製造された鋼板素材は、その複合効
果によってリードフレーム用素材として、耐錆性、打抜
き成形加工性、リードフレーム製造工程でのめっき被膜
の均一処理性、密着性、はんだ性能等にすぐれた効果を
発揮する。As described above, the steel sheet material manufactured by the above heat treatment method with a coating layer of Nt, Co, etc. applied to the steel components has excellent rust resistance, punching formability, lead frame material, etc. due to the combined effect. It has excellent effects on the uniformity of the plating film, adhesion, solder performance, etc. during the manufacturing process.

（実施例） 第１表に示す鋼成分の素材鋼板を冷間圧延後、脱脂、酸
洗による表面活性化処理を行なってから、被覆処理及び
加熱処理を行なってリードフレーム用素材を製造した。(Example) A raw steel plate having the steel components shown in Table 1 was cold rolled, subjected to surface activation treatment by degreasing and pickling, and then subjected to coating treatment and heat treatment to produce a lead frame material.

該評価材に対して、リードフレーム製品に要求される主
要性能について、各々以下の性能評価試験を実施して、
その性能評価を第２表に示す。The following performance evaluation tests were conducted on the evaluation materials regarding the main performances required for lead frame products.
The performance evaluation is shown in Table 2.

尚、評価材については、熱延において各種属さに評価材
を調整して、冷間圧下率を変化させて、厚さ０．２５４
ｍの評価材を得た。又、比較に使用した冷間圧延材は、
被覆層を設けない状態で、同一の熱処理を施こした。Regarding the evaluation material, the evaluation material was adjusted to various properties during hot rolling, and the cold rolling reduction rate was changed to obtain a thickness of 0.254.
An evaluation material of m was obtained. In addition, the cold rolled material used for comparison is
The same heat treatment was performed without providing the coating layer.

この結果、本発明の製造法による鋼板は、比較材に比べ
て、リードフレーム用素材として極めてすぐれた性能を
示す。As a result, the steel plate manufactured by the manufacturing method of the present invention exhibits extremely superior performance as a lead frame material compared to comparative materials.

〔評価試験方法〕[Evaluation test method]

■　本発明の拡散被覆層の密着性 Ｎｉ、Ｃｏ或いはＮｉとＣｏの合金の被覆層を設け、加
熱処理を行なった本評価材について、曲率半径が板厚と
同一の繰り返し曲げ加工を行ない、その後セロファンテ
ープを貼布、剥離して、被覆層の剥離程度を調査した。■ Adhesion of the diffusion coating layer of the present invention The evaluation material, which was coated with a coating layer of Ni, Co, or an alloy of Ni and Co and subjected to heat treatment, was repeatedly bent so that the radius of curvature was the same as the plate thickness, and then Cellophane tape was applied and peeled off, and the degree of peeling of the coating layer was investigated.

尚、評価基準は以下の方法によって行なった。The evaluation criteria were as follows.

◎・・・繰り返し回数１０回以上、めっき被覆層の剥離
なし ○・・・繰り返し回数７回以上〜９回でめっき被覆層の
剥離なし Δ・・・繰り返し回数４回以上〜６回でめっき被覆層の
剥離なし ×・・・繰り返し回数３回以下でめっき被覆層の剥離発
生 ■　打抜き成形加工性（スタンピング性）評価材に対し
て３２ビン型のリードフレーム形状に連続スタンピング
を行ない、リードフレーム形状への打抜き成形性を以下
の評価基準で評価し、その成形加工性の評価を行なった
。◎... No peeling of the plating coating layer after 10 or more repetitions ○... No peeling of the plating coating layer after 7 to 9 repetitions Δ... No peeling of the plating coating after 4 to 6 repetitions No peeling of layer ×...Plating coating layer peels off after 3 repetitions or less ■ Stamping processability (stamping property) Evaluation material was continuously stamped into a 32-bin type lead frame shape, and the lead frame shape was determined. The punching formability was evaluated using the following evaluation criteria, and the molding processability was evaluated.

◎・・・打抜き端面部のかえりの発生、素材の割れ発生
等殆んどなく、打抜き成形性極めて良好。◎...There is almost no occurrence of burrs on the punched end face or cracks in the material, and the punching formability is extremely good.

Ｏ・・・評価材の打抜き成形性は上記と同様良好である
が、若干成形機のポンチ、ダイスの連続運転による摩耗
損傷が発生。O: The punching formability of the evaluation material was as good as above, but there was some wear and tear caused by the continuous operation of the punch and die of the molding machine.

△・・・打抜き端面部にかえりが若干発生するか、或い
は成形材の装置から抜は性が劣るため打抜き成形時にト
ラブルが発生し易い。Δ: Slight burrs occur on the punched end surface, or troubles tend to occur during punching because the ability to remove the molded material from the device is poor.

×・・・打抜き成形によって割れが評価材に可成り発生
するか、或いはポンチ、ダイス等の摩耗が長期連続運転
によって可成り大。×: A considerable amount of cracking occurs in the evaluation material due to punching and forming, or wear and tear on punches, dies, etc. is significant due to long-term continuous operation.

■　耐食性能 （ａ）　　評価法Ａ 評価材の保管貯蔵時の耐錆性能を評価するために、評価
材を所定のリードフレーム形状（４８ビン型形状）に打
抜き加工後、リードフレーム製造工程での表面処理が施
こされるまでの保管時の耐錆性能の評価を以下の促進試
験法及び評価基準により、その平面部及び打抜き端面部
についての評価を行なった。■ Corrosion resistance performance (a) Evaluation method A In order to evaluate the rust resistance performance of the evaluation material during storage, after punching the evaluation material into a predetermined lead frame shape (48 bottle shape), it was punched in the lead frame manufacturing process. The rust resistance performance during storage before surface treatment was evaluated using the following accelerated test method and evaluation criteria for the flat part and punched end face part.

（６０分冷凍・結露（−５°Ｃ）→９０分高温湿潤（４
９°Ｃ１湿度≧９８％）→２４時間・室内放置（３０°
Ｃ））を１サイクルとして５サイクル評価試験を実施し
て、以下の評価基準で耐錆性能を相対評価した。(60 minutes freezing/condensation (-5°C) → 90 minutes high temperature and humidity (4
9°C1 Humidity ≧98%) → Leave indoors for 24 hours (30°
A 5-cycle evaluation test was conducted with C)) as one cycle, and the rust resistance performance was relatively evaluated using the following evaluation criteria.

平面部の耐錆性評価基準 ◎・・・赤錆発生率５％以下 Ｏ・・・　　〃　　５％超〜１０％以下Δ・・・　　〃
１０％超〜２０％以下 ×・・・　　〃２０％超 端面部の耐錆性評価基準 ◎・・・赤錆発生率１０％以下 Ｏ・・・　　〃１０％超〜２０％以下 Δ・・・　　〃２０％超〜４０％以下 ×・・・　　〃４０％超 （ｂ）　　評価法Ｂ リードフレーム製品の耐錆性を対象とした評価試験とし
て、リードフレーム形状（４８ピンの形状）に打抜き加
工後、脱脂、浸漬酸洗を行なって、厚さ３μのＣｕめっ
きを施こし、塩水噴霧試験（ＪＩＳ−Ｃ−５０２８）に
より、その耐食性を平面部及び端面部において赤錆発生
状況を観察、以下の評価基準により評価を行なった。Rust resistance evaluation criteria for flat parts ◎... Red rust occurrence rate 5% or less O... 〃 More than 5% to 10% or less Δ... 〃
More than 10% to less than 20%×...20% Rust resistance evaluation criteria for end face portion◎...Red rust occurrence rate less than 10%O... More than 10% to less than 20%Δ... More than 20% to less than 40% ×... More than 40% (b) Evaluation method B As an evaluation test for the rust resistance of lead frame products, after punching into a lead frame shape (48 pin shape), After degreasing and immersion pickling, Cu plating with a thickness of 3 μm was applied, and the corrosion resistance was evaluated using a salt spray test (JIS-C-5028) by observing the occurrence of red rust on the flat and end surfaces, and using the following evaluation criteria. The evaluation was carried out by

◎・・・塩水噴霧試験２４時間後の赤錆発生率１％未満 Ｏ・・・　　　〃　　　　　　　　赤錆発生率１％以上
〜５％未満 Δ　　　　〃　　　　　　　　赤錆発生率５％以上〜１
０％未満 ×・・・　　　〃　　　　　　　　赤錆発生率１０％以
上 ■　めっき性能 リードフレーム製造工程でのめっき性能を評価するため
に、以下の方法によりＣｕめっき及びｐｂ−５μ合金電
気はんだめっきを行ない、そのめっき性能を評価した。◎... Red rust occurrence rate after 24 hours of salt spray test less than 1% O... Red rust occurrence rate of 1% or more to less than 5% Δ Red rust occurrence rate of 5% or more to 1
Less than 0% ×... 〃 Red rust occurrence rate 10% or more ■ Plating performance In order to evaluate the plating performance in the lead frame manufacturing process, Cu plating and PB-5μ alloy electro-solder plating were performed by the following method, and the plating was evaluated. Performance was evaluated.

（ａ）　　評価法Ａ 評価材をリードフレーム形状に打抜き加工後、脱脂（リ
ン酸ソーダ系電解脱脂）後に、１０％ＨｚＳＯａ浴を用
いて３０℃で７．５秒間の浸漬酸洗を行ない、シアンＣ
ｕめっき浴を用いて電流密度７．５Ａ／ｄｍ”で厚さ３
μのＣｕ−めっきを施こし、Ｃｕめっき後の外観調査及
び以下の方法による曲げ加工試験を行なってその密着性
を併せ検討した。(a) Evaluation method A After punching the evaluation material into a lead frame shape, degreasing (sodium phosphate electrolytic degreasing), immersion pickling at 30°C for 7.5 seconds using a 10% Hz SOa bath, cyanide. C
3 thickness at a current density of 7.5 A/dm'' using a U plating bath.
μ Cu-plating was applied, and the appearance after Cu plating was examined and a bending test was conducted using the following method to examine the adhesion.

すなわち曲げ加工試験は、板幅０．５ＩＩＩＩ１１のア
ウターリード部について、長さ１５ｍｍに剪断後、ＭＩ
ＬＳＴＤ　８８３Ｃ／２００４に従い、一端を試験治具
に固定し、試料を垂直にぶら下げ、もう一端に２３０ｇ
のおもりを付けて試験治具を９０°Ｃに折り曲げ後、も
とにもどすという工程を繰り返し実施し、Ｃｕめっき密
着性の評価を行なった。In other words, in the bending test, the outer lead part with a plate width of 0.5III11 was sheared to a length of 15 mm, and then MI
According to LSTD 883C/2004, one end is fixed to the test fixture, the sample is suspended vertically, and the other end is loaded with 230 g.
The process of attaching a weight to the test jig, bending it to 90°C, and returning it to its original position was repeated, and the adhesion of the Cu plating was evaluated.

尚、評価は以下の評価基準で行なった。Note that the evaluation was performed based on the following evaluation criteria.

◎・・・Ｃｕめっき面は均一平滑でめっき欠陥存在せず
、繰り返し曲げ回数１０回以上でＣｕめっき層の剥離な
し。◎...The Cu plating surface is uniform and smooth, with no plating defects, and the Cu plating layer does not peel off even after repeated bending 10 times or more.

○・・・Ｃｕめっき面は均一平滑でめっき欠陥存在せず
、繰り一厚し曲げ回数６回以上でＣｕめっき層の剥離な
し。○...The Cu plating surface is uniform and smooth, with no plating defects, and the Cu plating layer does not peel off even after being bent one thickness and bent 6 times or more.

△・・・Ｃｏめっき面に部分的に明瞭なめっき欠陥が若
干発生するも、繰り返し曲げ回数６回以上でＣｕめっき
層の剥離なし。Δ...Although some clear plating defects occurred partially on the Co-plated surface, the Cu plating layer did not peel off after repeated bending 6 times or more.

×・・・Ｃｕめっき面にめっき欠陥が明瞭に発生すると
ともに、繰り返し曲げ回数５回以下でＣｕめっき層の剥
離発生。×... Plating defects clearly occur on the Cu-plated surface, and the Cu-plating layer peels off when the number of repeated bending is 5 times or less.

（ハ）評価法Ｂ 評価法Ａと同様のＣｕめっき後に、ワイヤーボンディン
グ時の加熱を受ける場合を想定して、４００℃で５分間
の加熱処理を行なった場合のＣｕめっき面に発生するブ
リスター（Ｃｕめっき層の微細な膨み）の発生状況を調
査してそのＣｕめっき層の密着性を評価し、以下の評価
基準でそのめっき性能の評価を行なった。(C) Evaluation method B After Cu plating similar to evaluation method A, blisters ( The occurrence of fine bulges in the Cu plating layer was investigated to evaluate the adhesion of the Cu plating layer, and the plating performance was evaluated using the following evaluation criteria.

◎・・・ブリスターの発生なし Δ・・・ブリスターが５×５−面積当りに換算して５点
以下発生 ×・・・ブリスターが５×５Ｃ−面積当りに換算して６
点以上発生 （Ｃ）　　評価法Ｃ 前記と同様の脱脂、酸洗の前処理を施こした後、アルカ
ノスルフォン酸系のＰｂ−５０％Ｓｎ電気はんだめっき
浴を用い、そのめっき性の評価を行なった。◎... No blisters occur Δ... Blisters occur at 5 x 5 points or less when calculated per area ×... Blisters occur at 5 x 5 C - 6 points when converted per area
(C) Evaluation method C After performing the same pretreatment of degreasing and pickling as described above, the plating properties were evaluated using an alkanosulfonic acid-based Pb-50%Sn electrosolder plating bath. Ta.

電気はんだめっき条件としては、めっき浴温５０°Ｃ１
電流密度１０Ａ／　ｄｍ”で厚さ５μのめっきを施こし
た。評価方法は、衝撃加工（評価面に直径１２．５ｍｍ
。Electrical solder plating conditions include plating bath temperature of 50°C1.
Plating with a thickness of 5 μm was applied at a current density of 10 A/dm. The evaluation method was impact processing (12.5 mm diameter
.

高さ９閣の半球を２ｍ／ｓｅｃの速度で衝撃荷重を加え
て押し込み加工）後、テープ貼布、剥離してそのめっき
層の密着性を評価した。After pressing a hemisphere with a height of 9 cm by applying an impact load at a speed of 2 m/sec, the tape was applied and peeled off to evaluate the adhesion of the plating layer.

評価基準は以下の方法により行なった。The evaluation criteria were as follows.

◎・・・めっき層の剥離なし Ｏ・・・めっき層の剥離面積１０％未満Δ・・・　〃　
　　剥離面積１０％以上〜３０％未満×・・・　〃　　
　剥離面積３０％以上■　はんだ性能 （６）評価法Ａ 評価材のはんだ性について、リードフレーム製造工程で
打抜き加工後、Ｃｕめつき処理の前にはんだが行なわれ
る工程を想定して、そのはんだ性について、特に打抜き
端面部のはんだ性についての評価を行なった。すなわち
、１１０ｍＸ５０のくけｌ／）形に剪断した評価材にロ
ジンアルコールフラックスを塗布して１０ｍの剪断面を
下方にし、Ｐｂ　−６０％Ｓｎ系はんだ浴に垂直に浸漬
した場合の濡れ応力と濡れ時間の測定により、そのはん
だ性を以下の評価基準により評価した。◎... No peeling of the plating layer O... Peeling area of the plating layer is less than 10% Δ... 〃
Peeling area 10% or more - less than 30%×...〃
Peeling area of 30% or more■ Soldering performance (6) Evaluation method A Regarding the solderability of the evaluation material, assume that soldering is performed after punching and before Cu plating in the lead frame manufacturing process. In particular, the solderability of the punched end face was evaluated. In other words, the wetting stress and wetting time were obtained when the evaluation material was sheared into a 110 m x 50 square (l/) shape, coated with rosin alcohol flux, with the 10 m shear plane facing downward, and immersed vertically in a Pb-60%Sn solder bath. The solderability was evaluated using the following evaluation criteria.

尚、はんだ性の上記評価試験は、打抜き加工直後と室内
に１．５月間保管した経時後について、各々評価した。The above evaluation test for solderability was performed immediately after punching and after being stored indoors for 1.5 months.

◎・・・濡れ応力４００■以上かつ濡れ時間７秒未満で
、はんだの濡れ性及び濡れ速度共極めて良好 Ｏ・・・濡れ応力３００■以上〜４００■未満かつ濡れ
時間８秒未満で、はんだの濡れ性及び濡れ速度共可成り
良好 △・・・濡れ応力２５０■以上〜３００■未満或いは濡
れ時間８秒以上〜１０秒未満で、はんだの濡れ性或いは
濡れ速度のいずれかが若干劣る×・・・濡れ応力２５０
■未満或いは濡れ時間１０秒以上で、はんだの濡れ性或
いは濡れ速度のいずれかが極めて劣る 向上記の濡れ応力及び濡れ時間の測定は、レスカ式のは
んだ濡れ性評価試験機を用い、フラックスを塗布した評
価材を溶融した温度３５０°Ｃのはんだ浴中に一定速度
（４ｒｉｍ／　５ｅｃ）で浸漬し、浸漬深さ４ａｉで３
０秒間浸漬を行ない、第２図に示すように、その際のメ
ニスコグラフ測定により、濡れ応力、濡れ時間の評価を
実施した。◎...Wetting stress of 400■ or more and wetting time of less than 7 seconds, both solder wettability and wetting speed are very good O...Wetting stress of 300■ or more and less than 400■ and wetting time of less than 8 seconds, solder Both wettability and wetting speed are fairly good △...Wetting stress is 250■ or more and less than 300■ or wetting time is 8 seconds or more and less than 10 seconds, and either the solder wettability or wetting speed is slightly poor.・Wetting stress 250
When measuring the wetting stress and wetting time described above, where either the solder wettability or the wetting speed is extremely poor when the solder wettability or wetting speed is less than The evaluated material was immersed in a melted solder bath at a temperature of 350°C at a constant speed (4rim/5ec), and the immersion depth was 4ai.
Immersion was performed for 0 seconds, and as shown in FIG. 2, wetting stress and wetting time were evaluated by meniscograph measurement at that time.

（ロ）評価法Ｂ 評価材を幅３０鵬×長さ１００ｍのくけい状に剪断後、
評価材に２７％ロジンアルコール・フラックスを塗布し
、はんだ組成Ｐｂ　−６０％Ｓｎ浴に端面部から長さ５
０１深さまで浸漬、温度３６０℃で１０秒間浸漬しては
んだを付着せしめた。(b) Evaluation method B After shearing the evaluation material into a wedge shape of 30 m wide x 100 m long,
Apply 27% rosin alcohol flux to the evaluation material, and apply it to a solder composition Pb-60% Sn bath for a length of 5 mm from the end surface.
The solder was immersed to a depth of 0.01 for 10 seconds at a temperature of 360°C to adhere the solder.

このあとワイヤーボンディング時の加熱処理を想定する
とともに、併せ経時に対する促進試験をも兼ねて、２０
０℃で６０分間の加熱処理を行なった場合のはんだの密
着性を評価した。After this, in addition to assuming heat treatment during wire bonding, it also served as an accelerated test for aging.
The adhesion of the solder was evaluated when heat treatment was performed at 0° C. for 60 minutes.

密着性評価法としては、曲率半径０．２５ｍｍ　（板厚
と同厚み）の繰り返し曲げ加工テストを行ない、はんだ
の剥離状況を調査してそのはんだ性能を評価した。As a method for evaluating adhesion, a repeated bending test with a radius of curvature of 0.25 mm (same thickness as the plate) was performed, and the state of solder peeling was investigated to evaluate the solder performance.

◎・・・繰り返し曲げ回数１０回以上で、はんだの剥離
及びはんだ層にクラック生成なし Ｏ・・・繰り返し曲げ回数６回以上で、はんだの剥離及
びはんだ層にクラック生成なし Δ・・・繰り返し曲げ回数３回以上で、はんだの剥離及
びはんだ層にクラック生成なし ×・・・繰り返し曲げ回数２回以下で、はんだの剥離及
びはんだ層にクラック生成 第１図は浸漬はんだのはんだ性及びはんだ密着性評価結
果を示すグラフであり、 （注）■は評価材のはんだ性について、１０１０ｍｍＸ
５０のくけい形に剪断した評価材にロジンアルコールフ
ラックスを塗布して、１０ＩＩＩＩｌｌの剪断面を下方
にして、Ｐｂ　−６０％Ｓｎ系はんだ浴に垂直に浸漬し
た場合の濡れ応力と濡れ時間の測定により、そのはんだ
性を以下の評価基準により評価した。◎...No peeling of solder or cracks in the solder layer after repeated bending 10 times or moreO...No peeling of solder or cracks in the solder layer after repeated bending 6 times or moreΔ...No peeling of solder or cracks in the solder layer after repeated bending 6 times or more No peeling of solder and no cracks in the solder layer after 3 or more bending times...No peeling of solder and no cracks on the solder layer after 2 or fewer bending cycles. Figure 1 shows the solderability and solder adhesion of immersion solder. This is a graph showing the evaluation results. (Note) ■ indicates the solderability of the evaluation material at 1010 mm
Measurement of wetting stress and wetting time when rosin alcohol flux is applied to the evaluation material sheared into a 50° wedge shape and immersed vertically in a Pb-60%Sn solder bath with the 10IIIll shear plane facing downward. The solderability was evaluated according to the following evaluation criteria.

尚、はんだ性の上記評価試験は、打抜き加工直後と室内
に１．５月間保管した経時後について、各々評価した。The above evaluation test for solderability was performed immediately after punching and after being stored indoors for 1.5 months.

その評価基準は以下のとおりである。The evaluation criteria are as follows.

◎・・・濡れ応力４００■以上でかつ濡れ時間７秒未満
ではんだの濡れ性及び濡れ速度共極めて良好 ○・・・濡れ応力３００■以上〜４００■未満でかつ濡
れ時間８秒未満ではんだの濡れ性及び濡れ速度弁可成り
良好 Δ・・・濡れ応力２５０■以上〜３００■未満或いは濡
れ時間８秒以上〜１０秒未満ではんだの濡れ性或いは濡
れ速度のいずれかが若干劣る×・・・濡れ応力２５０■
未満或いは濡れ時間１０秒以上で、はんだの濡れ性或い
は濡れ速度のいずれかが極めて劣る 尚、前記の濡れ応力及び濡れ時間の測定は、レスカ式の
はんだ濡れ性評価試験機を用い、フラックスを塗布した
評価材を溶融した温度３５０℃のはんだ浴中に一定速度
（４ｍｌ　５ｅｃ）で浸漬し、浸漬深さ４Ｍで、３０秒
間浸漬を行ない、第２図に示すように、その隙のメニス
コグラフ測定により濡れ応力、濡れ時間の評価を実施し
た。◎...Solder wettability and wetting speed are extremely good when wetting stress is 400■ or more and wetting time is less than 7 seconds ○...Solder is soldering when wetting stress is 300■ or more and less than 400■ and wetting time is less than 8 seconds Wettability and wetting speed valve fairly good Δ... Wetting stress of 250 to less than 300 ■, or wetting time of 8 to less than 10 seconds, either solder wettability or wetting speed is slightly poor ×... Wetting stress 250■
If the wetting time is less than 10 seconds or the wetting time is 10 seconds or more, either the solder wettability or the wetting speed is extremely poor.In addition, the above-mentioned wetting stress and wetting time were measured using a Resca-type solder wettability evaluation tester, and the flux was applied. The evaluated material was immersed in a melted solder bath at a temperature of 350°C at a constant speed (4 ml 5 ec), immersed at a depth of 4 m for 30 seconds, and as shown in Figure 2, the gap was measured by meniscograph. Wetting stress and wetting time were evaluated.

（注）２は各評価材にノンハロゲンタイプ・フラックス
（イソプロピルアルコールに１３％のロジンを含有せし
めたフラックス）を塗布して２３０°ＣのＰｂ　−６０
％Ｓｎはんだ浴に浸漬し、引き上げ後エアブロ−ではん
だ付着厚さ８μ目標に施こした。該評価材を長期経時後
の密着性を想定して１００°Ｃで６０分加熱処理し、衝
撃加工（評価面に直径１２　、５　ｍｍ、高さ９■の半
球を２ｍ／ｓｅｃの速度で衝撃荷重を加えて押し込み加
工）後、テープ貼布剥離して、その密着性を以下の評価
基準で評価する。(Note) 2: Pb-60 at 230°C after applying non-halogen type flux (flux containing 13% rosin in isopropyl alcohol) to each evaluation material.
%Sn solder bath, and after pulling it up, air blowing was performed to achieve a solder adhesion thickness of 8 μm. The evaluation material was heat-treated at 100°C for 60 minutes assuming adhesion after long-term aging, and impact-treated (a hemisphere with a diameter of 12 mm, 5 mm, and height of 9 cm was applied to the evaluation surface at a speed of 2 m/sec). After applying a load and pressing), the tape was peeled off and its adhesion was evaluated using the following evaluation criteria.

◎：はんだの剥離なし ○：はんだの剥離面積１０％未満 Δ：はんだの剥離面積が１０％以上３０％未満×：はん
だの剥離面積が３０％以上で極めて大（発明の効果） 以上説明したごとく本発明の製造法によれば、集積回路
などに使用するリードフレーム材料として、拡散被覆層
の密着性やスタンピング性とともに、耐食性、めっき性
、はんだ性に優れた鋼板を得ることができる。◎: No solder peeling ○: Solder peeled area is less than 10% Δ: Solder peeled area is 10% or more and less than 30% ×: Solder peeled area is 30% or more, extremely large (effects of the invention) As explained above. According to the manufacturing method of the present invention, it is possible to obtain a steel plate that is excellent in corrosion resistance, plating performance, and solderability as well as the adhesion and stamping properties of the diffusion coating layer as a lead frame material used for integrated circuits and the like.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は浸漬はんだのはんだ性及び密着性の評価結果を
示すグラフ、第２図はメニスコグラフによる濡れ応力、
濡れ時間の測定方法を説明する図面である。 代理人　弁理士　　秋　沢　政　光 他１名Figure 1 is a graph showing the evaluation results of the solderability and adhesion of immersion solder, Figure 2 is the wetting stress by meniscograph,
It is a drawing explaining the measuring method of wetting time. Agent: Patent attorney Masamitsu Akizawa and 1 other person

Claims (2)

【特許請求の範囲】[Claims] （１）重量％で、Ｃ；０．３０％以下、酸可溶Ａｌ；０
．００５〜０．１０％、Ｃｒ；３〜１０．５％を含有し
、残部Ｆｅ及び不可避的不純物からなるＣｒ含有鋼板を
冷間圧延後、その表面に片面当りの付着量が１００〜３
０００ｍｇ／ｍ＾２のＮｉ、Ｃｏ或いはＮｉとＣｏの合
金の被覆層を設け、次いで非酸化性雰囲気中の４５０℃
〜再結晶温度の温度範囲で１８０秒以下の加熱拡散処理
を施こす事を特徴とする耐食性、めっき性及びはんだ性
にすぐれたリードフレーム用表面処理鋼板の製造法。(1) In weight%, C: 0.30% or less, acid-soluble Al: 0
．． After cold rolling a Cr-containing steel plate containing 0.005 to 0.10%, Cr; 3 to 10.5%, and the balance consisting of Fe and unavoidable impurities, the amount of adhesion per one side on the surface of the steel plate is 100 to 3.
A coating layer of 000mg/m^2 of Ni, Co, or an alloy of Ni and Co is provided, and then heated at 450°C in a non-oxidizing atmosphere.
- A method for producing a surface-treated steel sheet for lead frames with excellent corrosion resistance, plating performance, and solderability, which is characterized by performing a heating diffusion treatment for 180 seconds or less in a temperature range of recrystallization temperature. （２）重量％で、Ｃ；０．３０％以下、酸可溶Ａｌ；０
．００５〜０．１０％、Ｃｒ；３〜１０．５％を含有し
、さらにＣｕ；０．０５〜１％、Ｎｉ；０．０５〜３％
、Ｍｏ；０．０５〜０．５％の１種又は２種以上を含有
し、残部Ｆｅ及び不可避的不純物からなるＣｒ含有鋼板
を冷間圧延後、その表面に付着量が１００〜３０００ｍ
ｇ／ｍ＾２のＮｉ、Ｃｏ或いはＮｉとＣｏの合金の被覆
層を設け、次いで非酸化性雰囲気中の４５０℃〜再結晶
温度の温度範囲で１８０秒以下の加熱拡散処理を施こす
事を特徴とする耐食性、めっき性及びはんだ性にすぐれ
たリードフレーム用表面処理鋼板の製造法。(2) In weight%, C: 0.30% or less, acid-soluble Al: 0
．． 005 to 0.10%, Cr; 3 to 10.5%, further Cu; 0.05 to 1%, Ni; 0.05 to 3%.
, Mo; 0.05 to 0.5% of one or more types, and the balance is Fe and inevitable impurities after cold rolling a Cr-containing steel plate, the amount of adhesion on the surface is 100 to 3000 m
g/m^2 of Ni, Co, or an alloy of Ni and Co, and then heat diffusion treatment for 180 seconds or less at a temperature range of 450°C to recrystallization temperature in a non-oxidizing atmosphere. A method for producing surface-treated steel sheets for lead frames that are characterized by excellent corrosion resistance, plating properties, and solderability.