JP2804453B2 - Sealing solution for gold-plated material and sealing method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing solution for a gold or gold alloy plating material provided with nickel or nickel-containing alloy plating of a metal material such as an iron alloy, iron, stainless steel, a high nickel alloy or the like as a base. The present invention relates to a sealing method.

[0002]

2. Description of the Related Art In general, a connector which is a connecting part for electronic equipment is made of a material in which brass or phosphor bronze is plated with nickel and further plated with gold.
However, gold is expensive, and various methods have been adopted for the purpose of reducing connector manufacturing costs. A typical method is to reduce the thickness of the gold plating, but 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 two types of sealing liquids, organic and aqueous. In the organic system, a halogen-based organic solvent is generally used as a solvent. Therefore, the use of the organic sealing solution is greatly restricted at present due to problems such as destruction of the ozone layer. On the other hand, water-based solvents use water as a solvent, so there is no problem in terms of environmental pollution.However, since lubricants such as paraffin, which is hardly soluble in water used in conventional organic sealing liquids, cannot be used, water-based solvents cannot be used. The treated plating has a problem that lubricity is low and the durability of the connector is inferior to that of the solvent type.

[0003]

Therefore, there is a need for a sealing solution and a sealing method which have no problem in environmental pollution and have a sealing effect equal to or higher than the conventional one. An object of the present invention is to provide an improved sealing treatment solution that can satisfy such a demand and a sealing treatment method using the same.

[0004]

Means for Solving the Problems As a result of research conducted by the present inventors to solve the above problems, the following surface treatment liquid and method have been invented. That is, the present invention provides: (1) a sealing solution for gold or a gold alloy plating material having nickel or an alloy containing nickel as a base plating as a metal material, wherein the benzol represented by the general formula (1) is used as an inhibitor. One or more selected from the group consisting of a triazole compound, a mercaptobenzothiazole compound represented by the general formula (2), and a triazine compound represented by the general formula (3).
001 to 1% by weight, one or two or more fatty acids represented by the following general formula (4) as a lubricant are contained in a total of 0.05 to 2% by weight, and an emulsifier is represented by a general formula (5)
And a total of one or two selected from the group consisting of monoalkyl phosphates represented by the formula (1) and dialkyl phosphates represented by the formula (6): 0.05 to 2 wt.
% Of the sealing liquid.

[0005]

Embedded image

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

[0007]

Embedded image

(Wherein R ₃ represents an alkali metal or hydrogen)

[0009]

Embedded image

Wherein R ₄ is —SH, an amino group substituted with an alkyl group or an aryl group, or an alkyl-substituted imidazolyl alkyl, and R ₅ and R ₆ are —NH ₂ , —SH or —S
M (M represents an alkali metal)] As a lubricant, one or more fatty acids represented by the following general formula (4) are contained in an amount of 0.05 to 2 wt% in total, and R ₇ -COOH (4) (Wherein, R ₇ represents a saturated or unsaturated chain hydrocarbon having 10 to 20 carbon atoms) As an emulsifier, a monoalkyl phosphate represented by the following general formula (5) and a compound represented by the following general formula (6) A pore-sealing solution containing 0.05 to 2 wt% in total of one or two selected from the group consisting of the dialkyl phosphates shown below.

[0011]

Embedded image

(Wherein, R ₈ represents alkyl or substituted alkyl, M represents hydrogen or an alkali metal) (2) Gold or gold alloy plating provided with nickel or an alloy containing nickel as a metal material as a base plating A sealing treatment method comprising applying the sealing treatment liquid according to claim 1 to a material. (3) Sealing characterized by applying a sealing treatment liquid according to (1) above, after processing gold or a gold alloy plating material having nickel or an alloy containing nickel as a base plating as a metal material, Processing method.

The inhibitor, which is the first essential component of the pore-sealing solution of the present invention, is one or two of the following compounds, ie, benzotriazole-based compounds, mercaptobenzothiazole-based compounds, and triazine-based compounds.
At least one species is selected and added to the processing solution. These inhibitors react with nickel, which is a base metal in the gold plated pinhole, to form a complex compound, and the complex compound fills the pinhole, thereby improving the corrosion resistance of the gold plating. The benzotriazole compound used in the present invention has the general formula (1)

[0014]

Embedded image

(Wherein, R ₁ represents hydrogen, alkyl, or substituted alkyl, and R ₂ represents an alkali metal, hydrogen, alkyl,
Represents a substituted alkyl). Preferred examples of the compound represented by the general formula (1) include, for example, benzotriazole (both R ₁ and R ₂ are hydrogen), 1-methylbenzotriazole (R ₁ is hydrogen, R ₂
There methyl), tolyltriazole (R ₁ is methyl, R ₂ is hydrogen), 1-(N, N-dioctyl amino methyl) benzotriazole (R ₁ is hydrogen, R ₂ is N, N-dioctyl amino methyl), etc. is there.

The mercaptobenzothiazole compound used in the present invention has the general formula (2)

[0017]

Embedded image

Wherein R ₃ represents an alkali metal or hydrogen. Preferred examples of the compound represented by formula (2) include mercaptobenzothiazole, sodium salt of mercaptobenzothiazole, and potassium salt of mercaptobenzothiazole. When R ₃ is an alkali metal in the general formula (2), the mercaptobenzothiazole-based compound can be easily dissolved in water. The triazine compound has the general formula (3)

[0019]

Embedded image

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

[0021]

Embedded image

Alternatively, there is an alkali metal salt such as Na or K. In the general formula (3), R ₅ and R ₆ are-
In the case of SM, the triazine compound can be easily dissolved in water. 0.001-1 w of inhibitor
When the content is less than 0.001 wt%, no sealing effect is recognized, and when it exceeds 1 wt%, an adverse effect on contact resistance is recognized. The lubricant, which is the second essential component of the sealing treatment liquid of the present invention, is selected from one or more fatty acids, and is added to the treatment liquid to contribute to improving the lubricity of the gold-plated material. The fatty acid used in the present invention is represented by the general formula (4) R ₇ —COOH (4) (where R ₇ represents a saturated or unsaturated chain hydrocarbon having 10 to 20 carbon atoms). This general formula (4)
Preferred examples of the compound represented by are lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and the like. The addition amount is in the range of 0.05 wt% to 2 wt% in total,
If it is less than 5 wt%, the lubricating effect cannot be obtained, and if it exceeds 2 wt%, an adverse effect on the appearance of the material after the sealing treatment is recognized.

The emulsifier, which is the third essential component of the present invention, is selected from one or more of the following compounds, ie, monoalkyl phosphates and dialkyl phosphates, and is added to the treatment solution. It functions as a lubricant emulsifier. In addition, the emulsifier has a lubricating effect. The monoalkyl phosphate used in the present invention has the general formula (5)

[0024]

Embedded image

(Wherein, R ₈ represents alkyl or substituted alkyl, and M represents hydrogen or an alkali metal). Preferred examples of the compound represented by the general formula (5) include lauryl acid monophosphate.

The dialkyl phosphate is represented by the general formula (6)

[0027]

Embedded image

(Wherein, R ₈ represents alkyl or substituted alkyl, and M represents hydrogen or an alkali metal). Preferred examples of the compound represented by the general formula (6) include lauryl acid diphosphate. The addition amount of the emulsifier is in the range of 0.05 wt% to 2 wt%.
If it exceeds wt%, an adverse effect on solderability is observed. The sealing treatment liquid has the above-described components, and the solvent can be appropriately selected from water or an organic solvent containing no halogen such as ethanol, acetone, and normal paraffin. However, considering economics and flammability, water is the most suitable solvent. If the solvent is water, adjust the temperature of the solution to 40-
Heating to 80 ° C facilitates emulsification of the components in water and further facilitates drying of the processed material.

As the treatment method, any method such as immersing the plated product in the treatment solution, spraying or applying the treatment solution can be used. However, in the present invention, regardless of the shape of the plated product, whether it is a plate, a strip, or a pressed part, if it is immediately after plating, that is, if it is a continuous line, processing in that line enhances various functions of the sealing process. Was found to be high. It is also effective to seal the plated product with the sealing solution of the present invention after processing such as pressing. Even with a metal material that has been sealed after plating, many of the functions of the sealing process are lost in the step of cleaning the press oil that has adhered in the subsequent press working. Therefore, the re-sealing process is effective.

[0030]

The present invention will be described in detail below with reference to examples. Male and female continuous terminals were each press-formed using a cold-rolled material of spring phosphor bronze (C5210) having a thickness of 0.2 mm. These were electroplated through a reel-to-reel continuous plating line. In the plating line, after degreasing and pickling, nickel plating of 1 μm in a Watts bath or P plating of 0.5 μm in an alkaline bath
d80% -Ni20% alloy plating is performed. Then, gold or a gold-cobalt alloy was plated on the contact portion with a thickness of 0.1 μm. In the continuous plating line, a sealing treatment step was provided after gold plating, and the sealing treatment was performed by penetrating and immersing the continuous terminals. In addition, ion-exchange water was used as a solvent of the sealing treatment liquid, and the solution temperature was set to 60 ° C. The thus-sealed male and female terminals were cut from the carrier portion, and the lead wires were crimped. Then, they were fitted and subjected to an evaluation test.

The contact resistance is DC 10 mA, open voltage 200.
It was measured in mV. Lubricity was evaluated by the insertion / extraction force of the connector terminal after the treatment. The corrosion resistance was evaluated by performing a sulfurous acid gas corrosion test under the following conditions and observing the surface of the sample after the test and measuring the contact resistance. Gas composition: SO ₂ 10 ppm Temperature: 40 ± 2 ° C. Humidity: 80 ± 5% RH Time: a 240-hour sealing treatment solution components, the test results of the sample after the sealing treatment are shown in Table 1.

[0032]

[Table 1]

Note 1) However, the abbreviations of the sealing solution in the table are as follows. A-1 Benzotriazole A-2 Sodium salt of mercaptobenzothiazole A-3 Sodium salt of 1,3,5-triazinethiol B-1 Oleic acid C-1 Lauryl acid phosphate monoester (monolauryl phosphate) C -2 Lauryl acid phosphate diester (dilauryl phosphate) Note 2) Test criteria (1) Initial contact resistance, contact resistance after corrosion test ○: 10 mΩ or less △: 10 to 20 mΩ ×: 20 mΩ or more (2) Appearance after corrosion test ：: Number of corrosion points is 10 or less in 5 cm square area of 50 × enlarged photograph Δ: 10 to 50 corrosion points in 5 cm square area of 50 × enlarged photograph ×: The number of corrosion points is 50 or more in the range of 5 cm square of the 50 × enlarged photograph. (3) Lubricity (insertion / extraction force) ○: Insertion force per pin is 100 g or less Removal force 50g
Below △: Insertion force per pin: 100 to 150 g, removal force: 5
0 to 100 g ×: Insertion force per pin is 150 g or more, withdrawal force 100
g or more

[0034]

As described above, the sealing solution of the present invention does not contain substances that pollute the environment, and the gold and gold alloy plated material treated with this solution has excellent corrosion resistance and lubricity. Have.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-311489 (JP, A) JP-A-5-311491 (JP, A) JP-A-5-311492 (JP, A) JP-A-4-111 159375 (JP, A) JP-A-4-160186 (JP, A) JP-A-3-215697 (JP, A) JP-A-4-160189 (JP, A) JP-A-4-160190 (JP, A) JP-A-4-160182 (JP, A) JP-A-5-311485 (JP, A) JP-A-7-258894 (JP, A) JP-A-7-258887 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) C25D 5/00-7/12

Claims (3)

(57) [Claims] 1. A sealing solution for a gold or gold alloy plating material comprising nickel or an alloy containing nickel as an undercoat as a metal material, wherein a benzotriazole-based inhibitor represented by the following general formula (1) is used as an inhibitor. One or two selected from the group consisting of a compound, a mercaptobenzothiazole-based compound represented by the following general formula (2), and a triazine-based compound represented by the following general formula (3)
0.001 to 1 wt% in total (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 is —SH, an amino group substituted with an alkyl group or an aryl group, or an alkyl-substituted imidazolyl alkyl, and R ₅ and R ₆ are —NH ₂ , —SH or —SM (M represents an alkali metal) Wherein one or more of the fatty acids represented by the following general formula (4) are contained as a lubricant in an amount of 0.05 to 2 wt% in total, and R ₇ —COOH (4) (where R ₇ is carbon The emulsifier comprises a monoalkyl phosphate represented by the following general formula (5) and a dialkyl phosphate represented by the following general formula (6) as an emulsifier. A pore-sealing solution containing 0.05 to 2 wt% in total of one or two selected from the group. Embedded image (Wherein, R ₈ represents alkyl or substituted alkyl, M represents hydrogen or an alkali metal) 2. A sealing process, wherein the sealing solution according to claim 1 is applied to a gold or gold alloy plating material having nickel or an alloy containing nickel as a base material as a metal material. Method. 3. A sealing material characterized by applying a sealing treatment liquid according to claim 1 after processing a gold or gold alloy plating material having nickel or an alloy containing nickel as a base plating as a metal material. Hole treatment method.