JPH09170096A - Sealing treatment for gold plating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing treatment for forming a high corrosion-resisting gold plating material (contact point) having no environmentally polluting property and having the low contact resistance. SOLUTION: In the sealing treatment for the gold or gold alloy plating material provided with nickel or alloy plating, etc., contng. nickel as a substrate on a base metal, D.C. electrolysis is executed at an interpole voltage in a range of 0.1 to 5.0V in the execution thereof using the plating material as an anode in an emulsion type-sealing treatment liquid formed by adding a 0.01 to 5.0wt.% self-emulsifying agent to an inhibitor-aqueous solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gold or gold having a base material made of a metal material such as copper alloy, iron, stainless steel, high nickel alloy and the like and plated with nickel or a nickel-containing alloy as a base material. The present invention relates to a method for sealing a plated alloy material and a connector contact that has been sealed. Particularly, the present invention relates to a sealing solution, a sealing method, and a contact that has been subjected to a sealing treatment that exhibits high corrosion resistance, long-term stability of electrical contact performance even when the thickness of the gold and gold alloy plating is thin, and has excellent lubricity. is there.

[0002]

2. Description of the Related Art A connector is the most typical connector for electronic equipment, and various connectors have been put to practical use. Connectors used in so-called industrial electronic devices that require a high degree of reliability, such as computers and communication devices, are made of a copper alloy for springs such as phosphor bronze and beryllium copper and are plated with gold. Commonly used. These connectors that require a high degree of reliability are required to have high corrosion resistance, long-term stability of electrical contact performance, and low insertion / removal force when inserting / removing the connector.
By the way, since gold is expensive, various methods have been adopted in order to reduce connector manufacturing cost. A typical method is to reduce the thickness of the gold plating. However, there is a problem that the thickness of the gold plating is reduced, the number of pinholes in the film increases exponentially, and the corrosion resistance is significantly reduced. One of the methods for solving this problem is a sealing treatment. 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 an organic type and an aqueous type in the sealing treatment. In the case of organic solvents, generally, a halogen-based organic solvent is used as a solvent, so that a problem of environmental pollution arises. The chromate method is a typical water-based method, but the chromate method may increase the contact resistance even though the effect of improving corrosion resistance may be observed, and the lubricity is low, which impairs the mating and unmating properties of the connector. It was

[0003]

Therefore, there is no problem in environmental pollution, and in addition to the corrosion resistance and long-term stability of electrical contact performance of the gold-plated material, a sealing treatment capable of simultaneously improving lubricity. Liquid and sealing methods are required.
It is an object of the present invention to provide a sealing treatment liquid and a sealing treatment method using the same which can satisfy such requirements, and also to provide a connector treated by the same. is there.

[0004]

In view of such circumstances, the present inventors have conducted intensive studies and as a result, have come to invent a sealing method and a connector contact which has been subjected to the following sealing treatment. That is, the present invention provides (1) a method for sealing gold or a gold alloy plating material having a base metal coated with nickel or an alloy plating containing nickel as a base material, wherein a self-emulsifier is added to the inhibitor aqueous solution in an amount of 0.1%. 01 ~
Performing direct current electrolysis with the plated material as an anode in an emulsion-type sealing treatment liquid formed by adding 5.0 wt%, the inter-electrode voltage E being in the range of 0.1 to 5.0 V. A method for sealing a gold or gold alloy plating material, characterized in that (2) the sealing treatment liquid is a total of one or more cyclic nitrogen compounds having a chelate-forming property with nickel or a base metal as an inhibitor. In 10
The above (1) is characterized by containing up to 1000 ppm.
(3) The connector contactor which has been subjected to the sealing treatment by the above method. In addition, the sealing treatment method of the present invention is, in other words, a method of producing a gold-plated material such as a sealed connector contact.

According to the present invention, nickel, which is a base metal in a pinhole of gold plating, is oxidized by holding the electrode potential of a material to be processed in an oxidized region of nickel, which is a base plating, to oxidize nickel and an inhibitor. Has a rust-preventive effect by filling the complex compound into the pinhole, and has a lubricating effect by adsorbing the self-emulsifier in the sealing solution to the gold plating surface and having a lubricating effect. It is a way to make it. The voltage E between the electrodes was set to 0.1 to 5.0 V for direct current electrolysis, which was 0.1 V.
This is because if the anode voltage is less than 1, the rustproofing effect will be significantly reduced. Also, if it exceeds 5.0 V, the contact resistance becomes high.

[0006] The self-emulsifying agent, which is an essential component of the present invention and is used as a lubricant, is capable of emulsifying itself when added to water even in the absence of an emulsifying agent to form an emulsion. Oiliness improver adsorbed on plating surface,
Alternatively, it acts as an extreme pressure additive. The self-emulsifier used in the present invention can be appropriately selected from one or more known self-emulsifiers, and is not limited at all. For example,

[0007]

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Wherein R is an alkyl or substituted alkyl, M is hydrogen, an alkali metal and n is an average addition mole number of ethylene oxide.

[0009]

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(Wherein, R represents an alkyl or substituted alkyl, M represents hydrogen or an alkali metal), and the like are effective. As the alkyl represented by R in the alkyl ether phosphate represented by the above formula, for example, a linear or branched alkyl having 6 to 30 carbon atoms, preferably 8 to 18 carbon atoms is used. As the substituent, for example, an alkylphenol group is preferable. When M represents an alkali metal, sodium, potassium and lithium are preferred. Particularly preferred specific examples of the alkyl ether phosphate include, for example, R
Is C ₈ H ₁₇ , M is H, n is 1, R is C ₁₂ H ₂₅ ,
For example, n is 4.

As the alkyl represented by R in the alkyl phosphate ester represented by the above formula, for example, a linear or branched alkyl having 1 to 18, preferably 4 to 12 carbon atoms is used. The substituent is preferably, for example, an alkylphenol group. The alkali metal represented by M is preferably sodium, potassium or lithium. Particularly preferred specific examples of the alkyl phosphate include, for example, those wherein R is C ₄ H ₉ , M is H, R is C ₁₀ H ₂₅ ,
M may be Na. The total amount of these self-emulsifying agents is set to 0.01 to 5.0 wt% because the effect of improving lubricity is low at a concentration of less than 0.01 wt% and 5.0 wt%.
This is because the contact resistance increases when the concentration exceeds%. Examples of the cyclic nitrogen compound that can form a chelate compound with a base metal such as copper or nickel used as an inhibitor in the present invention include a benzotriazole compound represented by the following formula (3) and a following formula (4).
Indazole compound represented by the following formula, benzimidazole compound represented by the following formula (5), indole compound represented by the following formula (6), 1,3,5-triazinethiol compound represented by the following formula (7) A mercaptobenzothiazole compound represented by the following formula (8) is effective.

[0012]

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

[0014]

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

[0016]

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

[0018]

[Chemical 6]

(Wherein R ₁ represents hydrogen, alkyl or substituted alkyl, R ₂ represents a carboxyl group, an alkali metal,
Represents hydrogen, alkyl, or substituted alkyl)

[0020]

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(Wherein R ₁ represents —SH, or an amino group substituted with an alkyl group or an aryl group, and M ₁ ,
M ₂ represents hydrogen or an alkali metal. )

[0022]

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(Wherein, R ₁ represents hydrogen, alkyl, substituted alkyl, or halogen; R ₂ represents an alkali metal, hydrogen,
The alkyl represented by R ₁ or R ₂ in the benzotriazole compound represented by the formula (3) is, for example, a straight chain having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. Alkyl or branched alkyl is used. As the substituent, for example, a carbonyl group or an alkali metal salt thereof is preferable. R ₂
Is an alkali metal, sodium, potassium,
Lithium is preferred. Particularly preferred specific examples include, for example,

[0024]

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There are, for example,

The alkyl represented by R ₁ or R ₂ in the indazole compound represented by the above formula (4) is, for example, a linear or branched alkyl having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. Used. As the substituent, for example, phenyl, carboxyl group and the like are preferable. When R ₂ represents an acyl group, it is preferably an acetyl group or a benzoyl group. When R ₂ represents an alkali metal, sodium, potassium and lithium are preferable.
Specific examples of particularly preferred indazole compounds include, for example,

[0027]

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Etc. As the alkyl represented by R ₁ and R ₂ in the benzimidazole compound represented by the formula (5), for example, a linear or branched alkyl having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms is used. .
As the substituent, a carboxyl group and an alkali metal salt thereof are preferable. When R ₂ represents an acyl group, it is preferably an acetyl group, a benzoyl group or the like. When R ₂ represents an alkali metal, sodium, potassium and lithium are preferred.

Specific examples of particularly preferable benzimidazole compounds include, for example,

[0030]

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Etc. As the alkyl represented by R ₁ and R ₂ in the indole compound represented by the formula (6), for example, a linear or branched alkyl having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms is used. As the substituent, a carboxyl group and an alkali metal salt thereof are preferable. When R ₂ represents an alkali metal, it is preferably sodium, potassium or lithium. Particularly preferred specific examples of the indole compound,

[0032]

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Etc.

The alkyl substituent of the substituted amino group represented by R ₁ in the 1,3,5-triazinethiol compound represented by the formula (7) has, for example, 1 to 30 carbon atoms,
Preferably 4 to 18 linear or branched alkyl are used. As the aryl substituent, for example, phenyl, tolyl and the like are preferable. When M ₁ and M ₂ represent an alkali metal, preferred are sodium, potassium and lithium. Particularly preferred specific examples of the 1,3,5-triazinethiol-based compound include:

[0035]

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There are, for example,

In the mercaptobenzothiazole compound represented by the above formula (8), the alkyl represented by R ₁ and R ₂ has, for example, 1 to 10 carbon atoms, preferably 1 carbon atom.
~ 3 straight-chain or branched alkyl, and the alkyl substituent includes a carboxyl group, an alkali metal salt thereof, fluorocarbon, and the like. Further, as the substituted amino group, (C
₄ H ₉ ) ₂ N- and the like are preferable. As an alkali metal,
Sodium, potassium and lithium are preferred. Equation (1)
Particularly preferable examples of the mercaptobenzothiazole derivative represented by

[0038]

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The total amount of these inhibitors is 10 to 10
00 ppm is preferred. This is because if the concentration is less than 10 ppm, the sealing function is low, and if the concentration exceeds 1000 ppm, the contact resistance increases.

When the pore-sealing treatment is performed after plating at the stage of a raw material such as a wire material, a plate material or a strip material, it is also effective to perform the pore-sealing treatment with the pore-sealing liquid and the pore-sealing treatment method of the present invention after pressing the plated product. Is. Even with a metal material that has been sealed after plating, the effect of the sealing may be reduced in the step of cleaning press oil or the like adhering in the subsequent press working. Therefore, the re-sealing process is effective. After the press working, plating and sealing can be performed. Even in the subsequent connector processing steps, until the final electronic device assembly,
Similarly, if there is a step of washing the plated product, the effect of sealing treatment is reduced, so that it is effective to appropriately perform sealing treatment according to the present invention. Therefore, the present invention also includes a connector processed by the sealing method of the present invention.

The metal material used as the plating base material in the present invention is a copper alloy such as copper, brass, phosphor bronze, titanium copper, beryllium copper, etc., according to the required characteristics of connectors such as iron, stainless steel and high nickel alloy. It can be appropriately selected and is not limited. A known plating method such as electroplating, electroless plating, or dry plating such as CVD or PVD can be applied to the plating method, and is not limited. Further, a known method can be applied as plating conditions. The gold alloy plating is an alloy plating based on gold, and is appropriately selected depending on the application. Hard plating containing a small amount of cobalt is widely used in connectors for improving wear resistance. The base plating is generally nickel, nickel-palladium alloyed with 80-90%, nickel-cobalt alloyed with 60-80%, etc., but the present invention is applicable to any alloy containing nickel. It is valid.

[0042]

The present invention will be described in detail below with reference to examples. Phosphor bronze for spring (C5210-H) thickness 0.2m
The male and female continuous terminals were each press-formed using a cold-rolled material of m. These were electroplated through a continuous reel-to-reel electroplating line. In the plating line, after degreasing and pickling, 1 μm by Watt bath
Nickel plating or 0.5 μm Pd80% -Ni20% alloy plating with an ammonia-based plating solution, and then gold or gold-cobalt alloy with 0.1 μm
The contact portion was partially plated with a thickness of m. In the continuous plating line, a sealing process was provided after gold plating, and the sealing process was performed by passing a continuous terminal. The surface-treated male and female terminals were cut from the carrier portion and lead wires were crimped, and then fitted together and subjected to an evaluation test.

Contact resistance is DC 10 mA, open-circuit voltage 200.
It was measured in mV. The lubricity was evaluated by measuring the insertion / extraction force of the connector terminal after the treatment. The corrosion conditions were as follows. Table 1 shows the results.

[0044]

[Table 1]

Note 1) However, the abbreviations of plating types and sealing treatment liquids in the table are as follows. N1: Ni N2: Pd-Ni K1: Au K2: Au-Co A-1: Benzotriazole compound represented by the formula (3) (R ₁ = R ₂ = H) A-2: Formula (4) Indazole-based compound represented by (R ₁ = R ₂ = H) A-3: Benzimidazole-based compound represented by Formula (5) (R ₁ = R ₂ = H) A-4: represented by Formula (6) indole compound represented _{(R 1 = R 2 = H} ) A-5: formula (7) represented by 1,3,5-triazine-thiol compound _{(R 1 = N (C 4} H 9), M 1 = H,
_{M 2 = Na) A-6} : the mercaptobenzothiazole compound represented by formula _{(8) (R 1 = R} 2 = H) B-1: represented by the formula (1-1) to (1-3) Alkyl ether phosphate (R = C ₈ H ₁₇ , M =
H, n = 2) B-2: Alkyl phosphates represented by the formulas (2-1) to (2-3) (R = C ₁₀ H ₂₁ , M = H) Note 2) The criteria for the test are as follows: It is as follows.

Initial contact resistance, contact resistance after corrosion test (average value of n = 5) ○: 10 mΩ or less △: 10 to 20 mΩ ×: 20 mΩ or more Appearance after corrosion test ○: No corrosion product △: Corrosion product Dotted x: Corrosion points are observed on the entire surface Lubricity (insertion / removal force) ○: Insertion force per contact pin 290g or less Extraction force 220g or less △: Insertion force per contact pin 290-300g
Removal force 220 to 230 g ×: Insertion force per contact pin 300 g or more Removal force 230 g or more

[0047]

As described above, the gold-plated material sealed according to the present invention has a low contact resistance immediately after the sealing treatment, and has a long-term stability of the contact performance even in a severe corrosive environment (high corrosion resistance, (Low contact resistance).

Claims (3)

[Claims] 1. A method for sealing a gold or gold alloy plated material having a base metal such as nickel or an alloy plating containing nickel as a base, in a method for sealing a hole, wherein an inhibitor aqueous solution contains 0.01 to 5.0 wt% of a self-emulsifier. Gold which is characterized in that the inter-electrode voltage E is in the range of 0.1 to 5.0 V in direct current electrolysis using the plated material as an anode in an emulsion-type sealing treatment liquid formed by adding gold. Alternatively, a method for sealing a gold alloy plated material. 2. The sealing treatment solution according to claim 1, which contains, as an inhibitor, one or more chelate-forming cyclic nitrogen compounds with nickel or a base metal in a total amount of 10 to 1000 ppm. Sealing method. 3. A connector contact which has been subjected to a sealing treatment by the method according to claim 1.