JP2717064B2 - Sealing treatment method for gold plated material - Google Patents

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. In these connectors requiring high reliability, in addition to high corrosion resistance and long-term stability of electrical contact performance, it is required that the insertion / extraction force at the time of insertion / extraction of the connector is low. 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 typical for water systems.However, the chromate method has the effect of improving corrosion resistance, but may increase contact resistance, and also has low lubricity and impairs connector insertion / extraction. Met.

[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.
An object of the present invention is to provide an improved sealing treatment solution capable of satisfying such a demand and a sealing treatment method using the same, and an object of the present invention to provide a connector treated thereby. It was done.

[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 ~
In the emulsion type sealing treatment solution formed by adding 5.0 wt%, when performing DC electrolysis using the plating material as an anode, the anode current density is 0.05 mA / d.
m ² or more, gold or sealing treatment method of the gold alloy plating material which comprises carrying out a range of power supply amount 0.05 × 10 ^-3 ~50 × 10 ^-3 coulombs / dm ^{2, (2)} sealing One or two of chelating cyclic nitrogen compounds with nickel or base metal as inhibitors in the treatment solution
The sealing method according to the above (1), wherein the connector contactor contains 10 to 1000 ppm in total of at least one kind. In addition, the sealing treatment method of the present invention is, in other words, a method for 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 reason why the anode current density is set to 0.05 mA / dm ² or more in direct current electrolysis is that at a lower anode current density, the rust-preventing effect is significantly reduced. In addition, the amount of electricity is 0.05 × 10 ^{−3 to} 5
0 × 10 ⁻³ coulomb / dm ² is 0.05 × 10
^{If the} amount of electricity is less than ^-3 coulomb / dm ² , the rust-preventive film is not sufficiently formed, so that the effect of the sealing treatment is reduced.
If it exceeds 0 × 10 ⁻³ coulomb / dm ² , the rust preventive film becomes thicker and the contact resistance becomes higher.

[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]

Embedded image

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]

Embedded image

(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. Etc. are effective. The total amount of these self-emulsifiers was set to 0.01 to 5.0 wt%,
If the concentration is less than 001 wt%, the lubricity improving effect is low,
If the concentration exceeds 5.0 wt%, the contact resistance increases. The cyclic nitrogen compound capable of forming a chelate compound with a base metal such as copper or nickel used as an inhibitor in the present invention includes, for example, a benzotriazole-based compound represented by the following formula (3), a benzotriazole-based compound represented by the following formula (4) An indazole compound represented by the formula:
A benzimidazole compound represented by the following formula (5), an indole compound represented by the following formula (6), a 1,3,5-triazinethiol compound represented by the following formula (7), and a compound represented by the following formula (8) The represented mercaptobenzothiazole-based compound is effective.

[0012]

Embedded image

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

[0014]

Embedded image

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

[0016]

Embedded image

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

[0018]

Embedded image

(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]

Embedded image

(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]

Embedded image

(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 carboxyl group or an alkali metal salt thereof is preferable. R
_{When 2} represents an alkali metal, sodium, potassium and lithium are preferred. Particularly preferred specific examples include, for example,

[0024]

Embedded image

And the like. As the alkyl represented by R ₁ or R ₂ in the indazole compound represented by the formula (4), for example, the alkyl having 1 to 10 carbon atoms, preferably 1 carbon atom
Up to 3 linear or branched alkyls are 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 preferred. Specific examples of particularly preferred indazole compounds include, for example,

[0026]

Embedded image

And the like.

The alkyl represented by R ₁ and R ₂ in the benzimidazole compound represented by the formula (5) is, 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. Particularly preferred specific examples of the benzimidazole compound, for example,

[0029]

Embedded image

And the like.

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

[0032]

Embedded image

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

[0034]

Embedded image

And the like. In the mercaptobenzothiazole compound represented by the formula (8), R ₁ , R ₂
As the alkyl represented by, for example, 1 to 10 carbon atoms,
Preferably, it is a straight-chain or branched alkyl of 1 to 3, and the substituent of the alkyl includes a carboxyl group, an alkali metal salt thereof, and fluorocarbon. As the substituted amino group, (C ₄ H ₉ ) ₂ N— and the like are preferable. As the alkali metal, sodium, potassium and lithium are preferable. Particularly preferred examples of the mercaptobenzothiazole-based compound include:

[0036]

Embedded image

The total amount of these inhibitors is 10 to 100
The reason why the concentration is set to 0 ppm is that when the concentration is less than 10 ppm, the rust prevention effect is low, and when the concentration exceeds 1000 ppm, the contact resistance increases. In the case where the sealing treatment is performed after plating at the stage of a material such as a wire, a plate, or a strip, it is also effective to perform a sealing treatment with the sealing treatment solution and the sealing treatment method of the present invention after pressing the plated product. 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.

In the subsequent connector processing steps,
If there is a step of washing the plated product until the final assembly of the electronic device, the effect of the sealing treatment is similarly reduced. Therefore, it is effective to appropriately perform the 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 serving as a plating base material in the present invention can be appropriately selected according to the required characteristics of various copper alloys such as copper, brass, phosphor bronze, titanium copper, beryllium copper, iron, stainless steel, and high nickel alloys. Nothing is restricted. 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.

[0039]

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.

The contact resistance is DC 10 mA, open 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. Gas composition: H ₂ S 3 ppm SO ₂ 10 ppm Temperature: 40 ± 2 ° C. Humidity: 80 ± 5% RH Time: 240 hours The results are shown in Table 1.

[0041]

[Table 1]

Note 1) However, the plating type and the abbreviation of the sealing solution in the table are as follows. N1: Ni N2: Pd-Ni K1: Au K2: Au-Co A-1: a benzotriazole-based compound represented by the formula (3) (R ₁ = R ₂ = H) A-2: a formula (4) in indazole compounds represented _{(R 1 = R 2 = H} ) A-3: wherein formula (5) benzimidazole compound represented by _{(R 1 = R 2 = H} ) A-4: in the 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 ×: Corrosion point is observed on the entire surface Lubricity (insertion / extraction force) ○: Insertion force per contact pin 290 g or less Removal force 220 g or less △: Insertion force per contact pin 290 to 300 g
Removal force 220 to 230 g ×: Insertion force per contact pin 300 g or more Removal force 230 g or more

[0044]

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) and high lubricity.

Claims (3)

(57) [Claims] 1. A method for sealing gold or a gold alloy plating material having a base metal such as nickel or an alloy plating containing nickel as a base, wherein a self-emulsifier is contained in an inhibitor aqueous solution in an amount of 0.01 to 5.0 wt%. In direct current electrolysis using the plating material as an anode in an emulsion type sealing solution formed by adding the anode, the anode current density is 0.05 mA / dm ² or more and the amount of electricity is 0.0
A method for sealing a gold or gold alloy plating material, wherein the method is performed in a range of 5 × 10 ⁻³ to 50 × 10 ⁻³ coulomb / dm ² . 2. An inhibitor in the pore-sealing solution, in which one or two or more of a chelate-forming cyclic nitrogen compound with nickel or a base metal is used in an amount of 10 to 1 in total.
The sealing treatment method according to claim 1, wherein the content is 000 ppm. 3. A connector contact which has been sealed by the method according to claim 1.