JP2003129254A - Surface treatment agent for copper or copper alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-soluble surface treatment agent which is excellent in heat resistance, does not damage the good solder wettability of copper or a copper alloy even when heated, and hardly allows an oxidized surface film to be formed on the surface of copper or a copper alloy even after the surface is exposed to high temperature and humidity. SOLUTION: This surface treatment agent contains 0.01-50 g/L at least one compound selected from among benzimidazole derivatives having oxy compounds bonded thereto and represented by formulas (1)-(3) (wherein, X and Z are each alkyl, alkenyl, alkynyl, aryl, aralkyl, halogen or hydrogen; Y is alkylene, alkenylene, alkynylene, arylene or aralkylene; a is 0-4; b is 0 or 1; and c is an integer of 0-7).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface treatment agent for copper and copper alloys, and more particularly to a water-soluble surface treatment agent used for a printed wiring board using copper or a copper alloy.

[0002]

2. Description of the Related Art Most printed wiring boards used for mounting electric products and electronic parts use copper or copper alloys for circuits. Therefore, various methods have been developed in order to prevent the wiring portion from deteriorating due to surface oxidation and to maintain good solderability. As a typical method, a method of covering the circuit portion with another metal and a method of covering with an organic film are known.

In the method of forming an organic film, an imidazole-based preflux (surface treatment agent) which causes a chemical reaction with a circuit part containing copper and selectively forms a film on this part.
The method of surface-treating the printed wiring board is useful. At present, as such a preflux, a water-soluble preflux containing a 2-position modified benzimidazole having an alkyl group or an aryl group bonded as a main component has been proposed. They are, for example, Japanese Patent No. 2913410 and Japanese Patent No. 2
It is disclosed in Japanese Patent No. 686168, Japanese Patent No. 2575242, and Japanese Patent No. 2923596.

[0004]

However, none of the above-mentioned prior arts has yet been found to exhibit heat-resistant and water-soluble properties which are sufficiently satisfactory for practical use. With regard to heat resistance in particular, with the recent mounting technology using lead-free solder, products have been manufactured at higher mounting temperatures than before, but due to this mounting temperature rise, surface treatment The current situation is that the heat resistance of the agent has not been able to follow. Specifically, when the printed wiring board is exposed to high temperature and high humidity, there have been problems that the solder wettability is deteriorated and the surface of copper or copper alloy is oxidized and deteriorated.

Therefore, in the present invention, a water-soluble surface treating agent which is excellent in heat resistance and which does not impair the good solder wettability of copper and copper alloys by heating, and copper which is surface-treated with the surface treating agent or The purpose is to provide a copper alloy. Further, another object of the present invention is to provide a water-soluble surface treatment agent in which a surface oxide film is difficult to form even after the surfaces of copper and copper alloy are exposed to high temperature and high humidity, and copper surface-treated with the surface treatment agent. Or to provide a copper alloy.

[0006]

Means for Solving the Problems As a result of intensive investigations by the present inventors, the use of a benzimidazole derivative having an oxy compound bonded at the 2-position described below as a main component improves various properties of the surface treatment agent, It has been found that the heat resistance is particularly improved.

That is, according to the present invention, a surface treatment agent for copper and copper alloys, which contains as a main component at least one of the benzimidazole derivatives of the following general formulas (1) to (3): The surface treatment agent is provided.

[0008]

[Chemical 2] In the formulas (1) to (3), the substituents X and Z represent one selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a halogen atom and a hydrogen atom, and a substituent Y Represents one selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group and an aralkylene group. a represents 0 to 4, b represents 0 or 1, and c represents an integer of 0 to 7.

In the present invention, the alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, alkylene group, alkenylene group, alkynylene group, arylene group and aralkylene group represented by X, Z and Y preferably have carbon atoms. 1 to 20. When there are a plurality of Xs, Zs, and Ys, they may be the same or different.

Next, the bath composition of the metal surface treating agent of the present invention will be described in detail. First, the general formula (1) to
The main component benzimidazole derivative represented by any of (3) is contained in the bath in an amount of 0.01 to 50 g / L, more preferably 0.1 to 10 g / L.

The benzimidazole derivatives represented by the above general formulas (1) to (3) can be produced as follows. That is, ortho-phenylenediamine or an ortho-phenylenediamine derivative, various oxycarboxylic acids, and paratoluenesulfonic acid are added in equimolar amounts, and synthesis is performed at about 200 ° C.

Specific examples of the benzimidazole derivative represented by the general formula (1) include 2- (pentoxymethyl).
Benzimidazole, 2- (heptoxymethyl) benzimidazole, 2- (nonyloxymethyl) benzimidazole, 2- (undecyloxymethyl) benzimidazole, 2- (tridecyloxymethyl) benzimidazole, 2- (pentadecyloxymethyl) ) Benzimidazole, 2- (heptadecyloxymethyl) benzimidazole, 2- (nonyloxypropyl) benzimidazole, 2- (nonyloxypentyl) benzimidazole, 2- (nonyloxyheptyl) benzimidazole, 2- (nonyloxy) Nonyl) benzimidazole.

Specific examples of the benzimidazole derivative represented by the general formula (2) include 2- (phenoxymethyl).
Benzimidazole, 2- (4-chlorophenoxymethyl) benzimidazole, 2- (2,4-dichlorophenoxymethyl) benzimidazole, 2- (2-chloro-4-methylphenoxymethyl) benzimidazole,
2- (1- (4-chlorophenoxy) ethyl) benzimidazole, 2- (2- (4-chlorophenoxy) ethyl) benzimidazole, 2- (3- (4-chlorophenoxy) propyl) benzimidazole, 2- (4-
(4-Chlorophenoxy) butyl) benzimidazole, 2- (1- (4-chlorophenoxy) -1-methylethyl) benzimidazole, 2- (1- (4-chlorophenoxy) propyl) benzimidazole, 2- ( Phenoxymethyl) -5-methylbenzimidazole, 2
-(4-chlorophenoxymethyl) -5-methylbenzimidazole, 2- (2,4-dichlorophenoxymethyl) -5-methylbenzimidazole, 2- (phenoxymethyl) -5-chlorobenzimidazole, 2- (4
-Chlorophenoxymethyl) -5-chlorobenzimidazole, 2- (2,4-dichlorophenoxymethyl)-
5-chlorobenzimidazole is mentioned.

Specific examples of the benzimidazole derivative represented by the general formula (3) include 2- (naphthoxymethyl).
Benzimidazole, 2- (4-chloronaphthoxymethyl) benzimidazole, 2- (2,4-dichloronaphthoxymethyl) benzimidazole, 2- (2-chloro-4-methylnaphthoxymethyl) benzimidazole,
2- (1- (4-chloronaphthoxy) ethyl) benzimidazole, 2- (2- (4-chloronaphthoxy) ethyl) benzimidazole, 2- (3- (4-chloronaphthoxy) propyl) benzimidazole, 2- (4-
(4-Chloronaphthoxy) butyl) benzimidazole, 2- (1- (4-chloronaphthoxy) -1-methylethyl) benzimidazole, 2- (1- (4-chloronaphthoxy) propyl) benzimidazole, 2- (naphthoxymethyl) ) -5-Methylbenzimidazole, 2
-(4-chloronaphthoxymethyl) -5-methylbenzimidazole, 2- (2,4-dichloronaphthoxymethyl) -5-methylbenzimidazole, 2- (naphthoxymethyl) -5-chlorobenzimidazole, 2 -(4
-Chloronaphthoxymethyl) -5-chlorobenzimidazole, 2- (2,4-dichloronaphthoxymethyl)-
5-chlorobenzimidazole is mentioned.

The metal surface treating agent of the present invention contains 0.1 to 400 g of an organic acid and / or an inorganic acid in order to dissolve the main component.
/ L, preferably 5-200 g / L. Examples of the organic acid include formic acid, acetic acid, fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, dibromoacetic acid, tribromoacetic acid, iodoacetic acid, diiodoacetic acid, triiodoacetic acid, propionic acid. , Butyric acid, hexanoic acid, glycolic acid,
Examples thereof include acrylic acid, benzoic acid, lactic acid, oxalic acid, malonic acid, succinic acid, adipic acid, malic acid, tartaric acid, citric acid, maleic acid, fumaric acid, salicylic acid, toluic acid, methanesulfonic acid, and toluenesulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid.

The metal surface treating agent of the present invention contains a metal salt of 1 mg / in order to further improve the film-forming property and heat resistance.
L-10 g / L, preferably 10 mg / L-1 g / L is added. Examples of the metal salt include zinc hydroxide, zinc oxide, zinc formate, zinc acetate, zinc chloride, zinc sulfide, zinc phosphate, lead hydroxide, lead oxide, lead formate, lead acetate, iron hydroxide,
Iron oxide, iron chloride, nickel hydroxide, nickel oxide, nickel chloride, copper hydroxide, copper oxide, copper chloride, copper sulfate, copper phosphate, copper carbonate, copper formate, copper acetate, copper oxalate, copper bromide, Silver hydroxide, silver oxide, silver iodide, silver hydantoin, palladium hydroxide, palladium oxide, palladium chloride, palladium sulfate, manganese hydroxide, manganese oxide, manganese chloride, manganese sulfate, manganese formate, manganese acetate, chromic acid, chromium Examples thereof include sodium acidate and potassium chromate.

The metal surface treating agent of the present invention contains a halogen compound in an amount of 1 mg / L to 10 g / L, preferably 10 mg / L to 1 in order to further improve the film forming property and heat resistance.
Add g / L. Examples of the halogen compound include sodium fluoride, potassium fluoride, ammonium fluoride, sodium chloride, potassium chloride, ammonium chloride,
Examples include sodium bromide, potassium bromide, ammonium bromide, sodium iodide, potassium iodide, and ammonium iodide.

In the metal surface treating agent of the present invention, in order to improve the wettability of the liquid, 1 μg / L of an anionic, cationic or nonionic surfactant or a mixture thereof is added if necessary. -10 g / L, preferably 10 μg /
L to 1 g / L is added. Examples of surfactants include alkylphenol ethylene oxide adducts.

Further, as another aspect of the present invention, there is provided copper or a copper alloy whose surface is treated with the above-mentioned surface treatment agent.
Since the surface treatment agent of the present invention is applied to this copper or copper alloy, the surface is unlikely to deteriorate even under high temperature and high humidity.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to Examples. However, the present invention is not limited to the following examples.

[0021]

Example 1 In this example, 1 g / L of 2- (undecyloxymethyl) benzimidazole represented by the general formula (1) was used as the main component of the surface treatment agent. Other,
As the bath composition of the surface treatment agent, an acid, a metal salt, a halogen compound and a surfactant were added so as to give an aqueous solution having a concentration shown in Table 1 described later. As a test piece, 10 × 50 mm,
A copper plate having a thickness of 0.3 mm was prepared and subjected to degreasing and soft etching as pretreatment. This copper plate is immersed in a bath, pH 3.3 of the bath, treatment temperature 40 ° C., treatment time 60 s
The surface treatment was performed under the conditions of. The treatment conditions are shown in Table 1 together with the bath composition.

The test piece surface-treated as described above was subjected to the following solder wettability test. In the following solder wettability 1 and 2, tin-lead eutectic solder was used for bath temperature 24
The zero cross time was measured by the meniscograph method at 0 ° C. with a commercially available post flux. 1) Solder wettability 1 The solder wettability of the test piece after standing for 96 hours in an environment of room temperature of 40 ° C. and humidity of 90% was evaluated. 2) Solder wettability 2 After being left in an environment of room temperature of 40 ° C. and humidity of 90% for 96 hours, the test piece heated at 200 ° C. for 30 minutes was evaluated for solder wettability. As shown in Table 1 described later, the evaluation results were good, with solder wettability 1 of 0.55 s and solder wettability 2 of 1.48 s.

[0023]

Example 2 In Example 2, except that the bath composition shown in Table 1 containing another benzimidazole derivative represented by the general formula (1) as the main component of the surface treatment agent was used. Similarly, the copper plate was subjected to surface treatment and solder wettability was evaluated. The evaluation results are shown in Table 1 below together with the bath composition.

[0024]

Examples 3 to 8 Examples 3 to 8 were carried out except that the bath compositions shown in Table 1 containing the benzimidazole derivative represented by the general formula (2) as the main component of the surface treatment agent were used. The copper plate was surface-treated in the same manner as in Example 1 to evaluate the solder wettability. The evaluation results are shown in Tables 1 and 2 described later together with the bath composition.

[0025]

[Examples 9 and 10] Examples 9 and 10 were carried out except that the bath composition shown in Table 1 containing the benzimidazole derivative represented by the general formula (3) as the main component of the surface treatment agent was used. The copper plate was surface-treated in the same manner as in Example 1 to evaluate the solder wettability. The evaluation results are shown in Table 3 below together with the bath composition.

[0026]

Comparative Examples 1 and 2 In Comparative Examples 1 and 2, the bath compositions shown in Table 3 containing benzimidazole and 2-nonylbenzimidazole having no oxy compound bonded as the main components of the surface treatment agent were used. Other than the above, the copper plate was subjected to surface treatment in the same manner as in Example 1 and solder wettability was evaluated. The evaluation results are shown in Table 3 below together with the bath composition.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

As is clear from the evaluation results of Tables 1 to 3, in comparison with the solder wettability of the comparative example, in all the examples using the surface treatment agent of the present invention, high humidity and high temperature and high humidity were used. It exhibited excellent solder wettability even after being exposed to the environment. This also indicates that the formed organic film on the surface is stable and the copper plate is not easily oxidized.

[0031]

When the water-soluble surface treatment agent of the present invention is applied, an organic coating film having excellent heat resistance and not impairing the solder wettability of copper and copper alloy by heating is formed on the surface of copper and copper alloy. it can. Further, when the surface treatment agent of the present invention is applied, a surface oxide film is not easily formed even after the surfaces of copper and copper alloys are exposed to high temperature and high humidity, and the treated surface is less likely to deteriorate.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masashi Kumagai             4 shares, 187 Usba, Hwagawa-cho, Kitaibaraki, Ibaraki             Ceremony Company Nikko Materials Isohara Factory F-term (reference) 4K026 AA06 BA01 BB10 CA16 CA33                       CA37 CA38                 5E319 AA03 AB05 AC13 CC33 CD60                       GG03 GG15

Claims (2)

[Claims] 1. A surface treatment agent for copper and a copper alloy, which contains as a main component at least one of benzimidazole derivatives represented by the following general formulas (1) to (3). [Chemical 1] (In the formulas (1) to (3), the substituents X and Z are an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group,
The substituent Y represents one selected from the group consisting of a halogen atom and a hydrogen atom, and the substituent Y represents one selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group and an aralkylene group. a represents 0 to 4, b represents 0 or 1, and c represents an integer of 0 to 7. ) 2. A copper or copper alloy surface-treated with the surface treatment agent according to claim 1.