JP6370658B2 - Antioxidant for Ni plating film of electronic component, electronic component, and method of manufacturing electronic component - Google Patents

Description

  The present invention relates to an antioxidant for Ni material, an electronic component, and a method for manufacturing the electronic component.

In order to maintain solder wettability, the connector, which is a connection part for electronic equipment, is plated with a nickel base on a copper material such as brass or phosphor bronze, or a stainless steel material such as SUS304, and then is plated with gold and / or tin. Or the material which gave tin alloy plating is generally used. However, since gold is expensive, various methods have been adopted for the purpose of reducing the connector manufacturing cost. A typical method is a method of reducing the thickness of the gold plating. However, as the gold plating thickness is reduced, there is a problem that the pinholes of the film increase exponentially and the corrosion resistance is remarkably reduced.
One method for solving this problem is sealing. That is, the surface of the gold plating is treated with various inorganic or organic chemicals to close the pinholes and improve the corrosion resistance.
There are two types of sealing treatment liquids: organic and aqueous. Since organic halogen solvents are generally used as organic solvents, the use of organic sealing liquids is currently greatly restricted due to problems such as ozone layer destruction. On the other hand, there is no problem in terms of environmental pollution because water is used as a solvent in the water system, but since a lubricant such as paraffin or the like that is hardly soluble in water used in conventional organic sealing liquids cannot be used, The plating treated with the above has a problem that the lubricity is low and the durability of the connector is inferior to that of the organic type.

Therefore, as a sealing treatment agent having no problem in environmental pollution and having a sealing treatment effect equivalent to or higher than that of the prior art, an inhibitor, a benzotriazole compound, a mercaptobenzothiazole compound, or a triazine thiol compound. The used sealing agent has patent documents 1-3, and the sealing agent which has a specific triazine type compound as an inhibitor is described in patent documents 4-5.
All of these are sealing agents for gold plating materials, and the nickel base plating is not treated at all.

  Patent Document 6 discloses a method for electrochemically treating a metal using a solution containing an aqueous solution of triazinethiols or an organic solvent as a solvent, an aqueous solution of an alkali phosphate or amine salt, or a solution using an organic solvent as a solvent. Is described. The coating on the metal surface that has been surface-treated by the electrodeposition method is different from the coating obtained by the dipping method, and it is dense and dense, and it has good adhesion. It is disclosed that it is excellent in performance. Examples of the metal include copper, a copper alloy, nickel, and the like.

  Further, although tin or tin alloy plating is relatively inexpensive, it is a soft metal, so that it is easily damaged during transportation, and there are problems of poor appearance and discoloration. Furthermore, if the tin or tin alloy plating step can be omitted, the cost can be reduced.

Japanese Patent No. 2804442 Japanese Patent No. 2717062 JP 2003-129257 A JP-A-5-31490 JP-A-5-311491 JP-A-5-51671

  An object of the present invention is to provide a nickel-based antioxidant capable of reducing the manufacturing cost in a connector or the like having a nickel base plating layer and a gold plating layer and / or a tin or tin alloy plating layer thereon. To do.

  As a result of intensive studies, the present inventors have made nickel base plating on the base material, and further gold plating and / or tin or tin alloy plating on the base material in connectors and the like which are connecting parts for electronic devices. Although the applied material is generally used, the nickel base plating layer is surface-treated with a specific antioxidant to suppress the oxidation of Ni, and then the gold plating layer and / or tin or tin The present inventors have found that solder wettability can be maintained and an increase in contact resistance can be suppressed without forming an alloy plating layer.

（式中、Ｒ₁は水素、アルキル、又は置換アルキルを表わし、Ｒ₂はアルカリ金属、水素、アルキル、又は置換アルキルを表わす）

（式中、Ｒ₃はアルカリ金属又は水素を表わす）

〔式中、Ｒ₄は−ＳＨ、−ＳＭ（Ｍはアルカリ金属を表わす）、アルキル基かアリール基で置換されたアミノ基、又はアルキル置換イミダゾリルアルキルを、Ｒ₅，Ｒ₆は−ＮＨ₂、−ＳＨ又は−ＳＭ（Ｍはアルカリ金属を表わす）を表わす。ただし、前記Ｒ₄、Ｒ₅、Ｒ₆のうち少なくともいずれか１つは−ＳＨ又は−ＳＭである。〕
［２］基材上に、Ｎｉめっき膜を有し、さらに前記Ｎｉめっき膜表面が、前記［１］に記載のＮｉ材の酸化防止剤を用いて表面処理されてなることを特徴とする電子部品。
［３］基材上に、Ｎｉめっき膜を形成し、前記Ｎｉめっき膜表面を、前記［１］に記載のＮｉ材の酸化防止剤を用いて表面処理することを特徴とする電子部品の製造方法。 That is, the present invention is as follows.
[1] An Ni material antioxidant containing at least an inhibitor, an amine compound, and an alkyl phosphate ester and / or a fatty acid, wherein the inhibitor is a benzotriazole compound represented by the following general formula (1) A Ni material comprising one or more selected from a mercaptobenzothiazole compound represented by the following general formula (2) and a triazine compound represented by the following general formula (3): Antioxidant.

(Wherein R ₁ represents hydrogen, alkyl, or substituted alkyl, and R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl)

(Wherein R ₃ represents an alkali metal or hydrogen)

[Wherein, R ₄ represents —SH, —SM (M represents an alkali metal), an amino group substituted with an alkyl group or an aryl group, or an alkyl-substituted imidazolylalkyl, R ₅ and R ₆ represent —NH ₂ , -SH or -SM (M represents an alkali metal). However, at least one of R ₄ , R ₅ and R ₆ is —SH or —SM. ]
[2] An electron having a Ni plating film on a substrate, and the surface of the Ni plating film is surface-treated with the Ni material antioxidant described in [1]. parts.
[3] Manufacture of an electronic component, wherein a Ni plating film is formed on a substrate, and the surface of the Ni plating film is surface-treated using the Ni material antioxidant described in [1]. Method.

  In connectors and the like which are connection parts for electronic devices, a material is generally used in which a nickel base plating is applied on a base material and further gold plating and / or tin or tin alloy plating is applied on the base material. By surface-treating the nickel base plating layer using the antioxidant of the Ni material of the invention, oxidation of Ni is suppressed and corrosion resistance is improved. Furthermore, solder wettability can be maintained without forming a gold plating layer and / or tin or tin alloy plating layer thereon, and an increase in contact resistance can also be suppressed. Therefore, the formation of an expensive gold plating layer and the formation of a tin or tin alloy plating layer can be omitted, and the manufacturing cost can be reduced.

  The antioxidant of the present invention is a Ni material antioxidant containing at least an inhibitor, an amine compound, and an alkyl phosphate ester and / or a fatty acid, wherein the inhibitor is a specific benzotriazole compound, mercapto 1 type or 2 or more types chosen from the benzothiazole type compound and the triazine type compound are contained.

（式中、Ｒ₁は水素、アルキル、又は置換アルキルを表わし、Ｒ₂はアルカリ金属、水素、アルキル、又は置換アルキルを表わす）
この一般式（１）で表わされる化合物のうち好ましいものを挙げると、例えば、１Ｈベンゾトリアゾール（Ｒ₁，Ｒ₂とも水素）、１−メチルベンゾトリアゾール（Ｒ₁が水素、Ｒ₂がメチル）、トリルトリアゾール（Ｒ₁がメチル、Ｒ₂が水素）、１−（Ｎ，Ｎ−ジオクチルアミノメチル）ベンゾトリアゾール（Ｒ₁が水素、Ｒ₂がＮ，Ｎ−ジオクチルアミノメチル）などである。 The benzotriazole-based compound is represented by the following general formula (1).

(Wherein R ₁ represents hydrogen, alkyl, or substituted alkyl, and R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl)
Preferred examples of the compound represented by the general formula (1) include 1H benzotriazole (both R ₁ and R ₂ are hydrogen), 1-methylbenzotriazole (R ₁ is hydrogen, R ₂ is methyl), Tolyltriazole (R ₁ is methyl, R ₂ is hydrogen), 1- (N, N-dioctylaminomethyl) benzotriazole (R ₁ is hydrogen, R ₂ is N, N-dioctylaminomethyl), and the like.

（式中、Ｒ₃はアルカリ金属又は水素を表わす）
この一般式（２）で表わされる化合物のうち好ましいものを挙げると、例えば２−メルカプトベンゾチアゾール、２−メルカプトベンゾチアゾールのナトリウム塩、２−メルカプトベンゾチアゾールのカリウム塩などがある。
一般式（２）においてＲ₃がアルカリ金属の場合メルカプトベンゾチアゾール系化合物の水への溶解が容易となる。 The mercaptobenzothiazole compound is represented by the following general formula (2).

(Wherein R ₃ represents an alkali metal or hydrogen)
Preferred examples of the compound represented by the general formula (2) include 2-mercaptobenzothiazole, sodium salt of 2-mercaptobenzothiazole, and potassium salt of 2-mercaptobenzothiazole.
In the general formula (2), when R ₃ is an alkali metal, the mercaptobenzothiazole compound is easily dissolved in water.

〔式中、Ｒ₄は−ＳＨ、−ＳＭ（Ｍはアルカリ金属を表わす），アルキル基かアリール基で置換されたアミノ基、又はアルキル置換イミダゾリルアルキル、Ｒ₅、Ｒ₆は−ＮＨ₂、−ＳＨ又は−ＳＭ（Ｍはアルカリ金属を表わす）を表わす。ただし、前記Ｒ₄、Ｒ₅、Ｒ₆のうち少なくともいずれか１つは−ＳＨ又は−ＳＭである。〕
この一般式（３）で表わされる化合物のうち好ましいものを挙げると例えば以下のものがある。 The triazine thiol compound is represented by the following general formula (3).

[Wherein R ₄ is —SH, —SM (M represents an alkali metal), an amino group substituted with an alkyl group or an aryl group, or an alkyl-substituted imidazolylalkyl, R ₅ , R ₆ are —NH ₂ , — SH or -SM (M represents an alkali metal). However, at least one of R ₄ , R ₅ and R ₆ is —SH or —SM. ]
Preferred examples of the compound represented by the general formula (3) include the following.

Alternatively, there are alkali metal salts such as Na or K. In the general formula (3), when R ₅ and R ₆ are —SM, the triazine thiol compound is easily dissolved in water.

  The amine compound may be any of primary amine, secondary amine, and tertiary amine, alkylamine (trimethylamine, triethylamine, diethylamine, etc.) or alkanolamine (monoethanolamine, diethanolamine, triethanol). Amine).

The antioxidant of the present invention further contains an alkyl phosphate ester and / or a fatty acid.
The alkyl phosphate ester is added to the antioxidant and functions as an emulsifier for the lubricant. Furthermore, there is also a lubricating action.
The fatty acid functions as a lubricant and contributes to improving the lubricity of the Ni plating film by being added to the antioxidant.

The alkyl phosphate ester is preferably a monoalkyl phosphate ester or a dialkyl phosphate ester.
The monoalkyl phosphate ester and dialkyl phosphate ester are obtained by dehydration condensation of phosphoric acid and an aliphatic alcohol. The aliphatic alcohol preferably has 6 to 24 carbon atoms, and preferably has 10 to 20 carbon atoms. More preferably. For example, decyl alcohol, lauryl alcohol, myristyl alcohol, cetanol, stearyl alcohol, oleyl alcohol and the like are more preferable.
These may be monoesters or diesters, and each may be used alone, but a mixture of monoesters and diesters or a mixture of a plurality of phosphate esters having different alcohol components may be used. Absent. As these monoalkyl phosphate esters and dialkyl phosphate esters, commercially available products can be used.

As a fatty acid, the fatty acid shown by following General formula (4) is preferable.
R ₇ —COOH (4)
(Wherein R ₇ represents a saturated or unsaturated chain hydrocarbon having 6 to 24 carbon atoms)
Among the fatty acids represented by the general formula (4), R ₇ is a saturated or unsaturated chain hydrocarbon having 10 to 20 carbon atoms, such as lauric acid, myristic acid, palmitic acid, Stearic acid, oleic acid, linoleic acid and the like.

The antioxidant of the present invention is an aqueous solution, and the addition amount of the inhibitor in the antioxidant is preferably in the range of 0.001 to 10 wt%. If it is less than 0.001 wt%, the antioxidant effect is not recognized, and if it exceeds 10 wt%, it is not preferable in terms of cost.
Further, the content of the amine compound is preferably 0.001 to 20 wt%. If it is less than 0.001 wt%, the antioxidant effect is not recognized, and if it exceeds 20 wt%, it is not preferable in terms of cost.
The addition amount of the alkyl phosphate is preferably in the range of 0.001 to 20 wt%. If it is less than 0.001 wt%, the antioxidant effect is not recognized, and if it exceeds 20 wt%, it is not preferable in terms of cost.
The addition amount of the fatty acid is preferably in the range of 0.001 to 20 wt%. If it is less than 0.001 wt%, the antioxidant effect is not recognized, and if it exceeds 20 wt%, it is not preferable in terms of cost.

  The antioxidant of the present invention preferably has a pH of 7-10. If the pH is less than 7, the solution may become unstable. If the pH exceeds 10, the antioxidant effect may be insufficient.

  The antioxidant of the present invention is applied to the surface of a Ni material to prevent its oxidation, and can maintain solder wettability without forming gold plating or tin or tin alloy plating on the surface, thereby increasing contact resistance. Can also be suppressed. The Ni material may be a material mainly composed of Ni, but in particular, a material having a Ni plating film on the substrate is preferable.

The electronic component of the present invention has a Ni plating film on a substrate, and the surface of the Ni plating film is surface-treated using the antioxidant of the present invention.
Examples of the base material include copper, copper alloy, iron, and iron alloy.
The copper or copper alloy of the base material may be obtained by a general known production method. The copper alloy includes at least one element selected from titanium, tin, nickel, cobalt, silver, lead, zinc, aluminum, beryllium, manganese, iron, zirconium, chromium, phosphorus, silicon, magnesium, arsenic, and tellurium. And an alloy containing copper. The copper alloy preferably has a copper content exceeding 50% by mass.
The iron or iron alloy of the base material may be obtained by a general known production method. Examples of the iron alloy include stainless steel (SUS) and 42 alloy. The iron alloy preferably has an iron content exceeding 50% by mass.

The Ni plating film can be formed by electroless plating or electrolytic plating. It is preferable to form by electrolytic plating, and as the electrolytic Ni plating solution, a known plating solution used for manufacturing electronic components can be used. For example, a Ni plating solution such as a sulfamic acid bath or a watt bath can be preferably used. Moreover, you may add a well-known brightener to each bath. As the brightener, aromatic sulfonic acids such as benzenesulfonic acid, aromatic sulfonamides such as p-toluenesulfonamide, and aromatic sulfonimides such as saccharin are preferably used. Further, it may be co-deposited with phosphorus or the like for the purpose of improving the corrosion resistance of nickel plating.
Ni plating conditions may also be known plating conditions.
The thickness of the Ni plating film is preferably 0.5 to 5 μm.

The surface of the Ni plating film is surface-treated using the antioxidant of the present invention.
The treatment method may be a method of forming a coating on the surface of the Ni plating film, for example, a method of simply immersing in an antioxidant, a method of spraying an antioxidant in a shower, or an air coater, blade coater, rod Examples of the method include coating using a device such as a coater, knife coater, gravure coater, reverse coater, cast coater.
In the case of immersion, it is sufficient to immerse at room temperature to 70 ° C., preferably 30 to 60 ° C. for several seconds to 1 minute. When the liquid temperature exceeds 70 ° C., the load on the equipment increases. When Ni is already oxidized, a pretreatment may be performed to remove the oxide film.
After treatment, wash with water and dry.

  Examples of the electronic component of the present invention include a connector that is a connection component for an electronic device. In particular, it can be suitably used for a shell case or the like in which the proportion of nickel plating is large and soldering strength is required.

Examples 1-5, Comparative Examples 1-5
Copper or copper alloy material is plated with 2μm of electrolytic nickel on the entire surface with a sulfamic acid bath, then treated with antioxidation under the conditions shown in Table 1, thoroughly washed with water, and dried with a drier to form an antioxidant coating. Formed.
Note that ion-exchanged water was used as a solvent for the antioxidant.
In Table 1, lauryl phosphate and decyl phosphate used for the sealing agent are a mixture of a monoester and a diester. 1,3,5-triazinethiol is the tri-Na salt of 1,3,5-triazine-2,4,6-trithiol.

[Corrosion resistance]
The obtained substrate was subjected to a salt spray test (based on JISZ2371) for 12 hours to evaluate corrosion resistance. The results are shown in Table 1.
Evaluation criteria:
○: Almost no corrosion.
Δ: Black spot-like corrosion is observed in some places.
X: A brown and / or green corrosion point is observed in some places.

[Solder wettability]
For the solder wettability, the sample after the pressure cooker test (105 ° C./100% RH × 8 h) was evaluated. The solder was Sn-3Ag-0.5Cu (260 ° C.), and the state after immersion for 3 seconds was visually confirmed.
○: Solder wet area with respect to solder immersion surface is 90% or more △: Solder wet area with respect to solder immersion surface is 50% or more and less than 90% ×: Solder wet with respect to solder immersion surface Less than 50%

[Contact resistance]
For the contact resistance, a sample after a pressure cooker test (105 ° C./100% RH × 8 h) was evaluated. MS2005 (Factk Ltd.) was used, and the measurement was performed under the condition of a load of 5 g.
○: Contact resistance less than 200 mΩ Δ: Contact resistance 200 mΩ or more and less than 500 mΩ ×: Contact resistance 500 mΩ or more

Claims (3)

An antioxidant for the Ni plating film of an electronic component having a Ni plating film on a substrate,
The antioxidant is at least, contain the inhibitor, and an amine compound, an alkyl phosphoric acid ester and / or fatty acids,
1 wherein the inhibitor is selected from a benzotriazole compound represented by the following general formula (1), a mercaptobenzothiazole compound represented by the following general formula (2), and a triazine compound represented by the following general formula (3). Contains seeds or two or more ,
In the antioxidant, the inhibitor content is 0.001 to 10 wt%, the amine compound content is 0.001 to 20 wt%, and the alkyl phosphate ester content is 0.001 to 0.001. An antioxidant for a Ni plating film of an electronic component , wherein the content of the fatty acid is 20 wt% and the content of the fatty acid is 0.001 to 20 wt% .

(Wherein R ₁ represents hydrogen, alkyl, or substituted alkyl, and R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl)

(Wherein R ₃ represents an alkali metal or hydrogen)

[Wherein, R ₄ represents —SH, —SM (M represents an alkali metal), an amino group substituted with an alkyl group or an aryl group, or an alkyl-substituted imidazolylalkyl, R ₅ and R ₆ represent —NH ₂ , -SH or -SM (M represents an alkali metal). However, at least one of R ₄ , R ₅ and R ₆ is —SH or —SM. ] An electronic device comprising: a Ni plating film on a substrate; and the surface of the Ni plating film is surface-treated using the antioxidant for the Ni plating film of the electronic component according to claim 1. parts. An Ni plating film is formed on a substrate, and the surface of the Ni plating film is surface-treated with the antioxidant for the Ni plating film of the electronic component according to claim 1. Method.