JP2923596B2 - Surface treatment agent for copper and copper alloys using imidazole compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treating agent for copper and copper alloys containing a specific imidazole compound as an active ingredient. The surface treating agent of the present invention is particularly useful as a rust inhibitor for printed wiring boards.

[0002]

2. Description of the Related Art As a method of preventing rust on a circuit made of copper or a copper alloy of a printed wiring board and maintaining solderability, there are a method of covering the circuit with another metal and a method of covering the circuit with an organic film. They are properly used in terms of surface smoothness and the like.

[0003] Materials for forming an organic film used in the latter method include a rosin-based preflux for coating the entire printed wiring board and an alkylimidazole-based preflux for selectively forming a film on a copper circuit portion by a chemical reaction. There is.

[0004] Rosin preflux is a natural rosin,
A solution in which a rosin ester, a rosin-modified maleic resin, or the like is dissolved in an organic solvent is applied to the entire printed wiring board, treated by spraying or dipping, and then dried to form a film. However, this method has problems in working environment and safety because the organic solvent is volatilized. For this reason, a special device including an exhaust means such as a draft is required.

Therefore, there is an increasing demand for using a water-soluble alkylimidazole-based preflux which is excellent in work environment and safety. However, the coating film of the alkylimidazole-based preflux has a disadvantage that it is deteriorated when exposed to a high temperature, hinders the action of post-flux used in soldering, and lowers solderability.

In recent years, the method of joining electronic components on a printed wiring board has shifted to a surface mounting method, and the circuit is increasingly exposed to high temperatures due to temporary fixing of components, reflow of cream solder, and the like. I have. Therefore, a water-soluble surface treatment agent that does not reduce solderability even after being exposed to a high temperature has been required.

As a device developed to meet this requirement, Japanese Patent Application Laid-Open No. 3-124395 discloses a preflux using a benzimidazole compound having a hydrogen atom, an alkyl group or a phenyl group at the 2-position. I have.

As described in the above publication, efforts have been made to improve the heat resistance of alkylimidazole-based prefluxes, but in reality, satisfactory performance has not been obtained.

The present invention has been made in view of the above points, and has as its object to provide a surface treating agent for copper and a copper alloy which is excellent in working environment and safety and further improved in heat resistance. .

[0010]

SUMMARY OF THE INVENTION A volatile solvent is not used,
After various studies to obtain a surface treatment agent with good solderability even after exposure to high temperatures, the general formula
(4) :

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

Embedded image (Where A ¹ is an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, phenylcarbonyl group or halogen atom, A ⁴ is an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, phenylcarbonyl group Or a halogen atom, R ² is an alkylene group, alkenylene group, alkynylene group or arylene group (Arylene), a is an integer of 0 to 4, b is 0 or 1, c is an integer of 0 to 7)

[0018]

[0019]

General formula (6):

[0021]

Embedded image (In the formula, d is an integer of 1 to 3, and A ¹ , A ⁴ , R ² , a and b are the same as described above.)

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

Alternatively, the general formula (14):

[0037]

Embedded image (Where A ⁸ and A ⁹ are an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group or a phenylcarbonyl group, respectively)

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

It has been found that the imidazole-based compound or a salt thereof represented by the formula (1) can form a heat-resistant film having excellent solderability on the copper surface.

[0047]

[0048]

[0049]

Specific examples of the compound represented by the general formula (4) include, for example, 2- (α-naphthylmethyl) benzimidazole, 2- (γ-naphthylmethyl) benzimidazole, γ-naphthylbenzimidazole, α-naphthyl Benzimidazole, 2- (γ-naphthylethyl) -4
-Vinylbenzimidazole, 5,6-dichloro-2-
(Α-naphthyldichloromethyl) benzimidazole,
6-isobutyl-2- (γ-naphthylethylene) benzimidazole, 7-octyl-2- (4-methyl-1-
Naphthylenepropyl) benzimidazole, 4-chloro-2- (3-hexyl-2-naphthylenebutyl) benzimidazole, 5-benzyl-2- (5-chloro-1-
Naphthyleneisopropyl) benzimidazole, 2-
(2-naphthyl (2-penten-4-ynyl) benzimidazole, 2- (5-chloronaphthylene) benzimidazole, 7-methyl-2- (5-ethyl-2-naphthylene-t-butyl) benzimidazole, 4-chloro-
6-ethyl-2-naphthylethylbenzimidazole,
6-cyclohexyl-2- (5-bromo-6-ethylnaphthyleneethyl) benzimidazole, 4-phenyl-
2- (3-vinyl-2-naphthylenepropyl) benzimidazole, 6-decyl-2-naphthyloctylbenzimidazole, 2- (7-phenethyl-2-naphthyleneethyl) benzimidazole, 2- (6-pyridyl-3)
-Methyl-2-naphthylenemethyl) benzimidazole, 6-thionyl-2- (6-p-chlorophenyl-2)
-Naphthylene-p-phenylene) benzimidazole,
4-quinolyl-2- (2-naphthyl-3-methylbenzyl) benzimidazole, 2- (7-benzoyl-2-
Naphthylenepropyl) benzimidazole, 5-furfuryl-2- (7-butyryl-2-naphthalenestyryl)
Benzimidazole, 2- (7-methoxy-2-naphthylenecyclohexane-1,5-yen) benzimidazole, 6-morpholino-2- (4,5,8-trichloro-2-naphthylmethyl) benzimidazole, 2-
(7-indenyl-2-naphthylenemethyl) benzimidazole, 5-tolylsulfonyl-2-naphthylpyridylene benzimidazole, 4-triazine-2- (7
-T-butyl-2-naphthylene-3-methyl-2-butenyl) benzimidazole, 5-aldehyde-2- (7
-Butanone-2-naphthylenehexyl) benzimidazole, 2- (7-chloroethyl-2-naphthylenemethyl) benzimidazole , 4,5-dimethyl-2-
((4'-ethylphenyl) naphthyl) benzimidazo
And the like .

[0051]

Specific examples of the compound represented by the general formula (6) include, for example, 2- (2-thienyl) benzimidazole, 2- (2- (5-ethyl) thienyl) benzimidazole, 2- (2- ( 5-chloro) thienyl) benzimidazole, 2- (2- (4-chloro) thienyl) benzimidazole, 5-chloro-2- (2-thienyl) benzimidazole, 5-methyl-2- (2-thienyl)
Benzimidazole, 2- (2-thienyl) -5-benzoylbenzimidazole, 5-phenyl-2- (2-
Thienyl) benzimidazole, 5-phenethyl-2-
(2-thienyl) benzimidazole, 2- (2-thienylmethylene) benzimidazole, 2- (2-thienylethylene) benzimidazole, 2- (2-thienylpropylene) benzimidazole, 2- (2-thienylisobutylene) benzo Imidazole, 5-chloro-2-
(2- (5-ethyl) thienyl) benzimidazole,
5-methyl-2- (2- (5-chloro) thienyl) benzimidazole, 5-phenethyl-2- (2- (5-isopropyl) thienyl) benzimidazole, 2- (2
-(5-isopropyl) thienylethylene) benzimidazole, 5-chloro-2- (2- (5-methyl) thienylmethylene) benzimidazole and the like.

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

Specific examples of the compound represented by the general formula (14) include, for example, 5,5'-bibenzimidazole,
-Methyl-2'-ethyl-5,5'-dibenzimidazole, 2-nonyl-2'-isopropyl-5,5'-dibenzimidazole, 2-vinyl-2'-styryl-
4,5′-dibenzimidazole, 2-ethynyl-2 ′
-Phenyl-4,4'-dibenzimidazole, 2-naphthyl-2'-tolyl-5,5'-dibenzimidazole, 2-phenethylpentyl-2'-cinamyl-5,
5'-dibenzimidazole, 2-phenethyl-2'-
Phenylcarbonyl-4,5'-dibenzimidazole, 2-chlorophenylethylene-2'-phenylbutyl-5,5'-dibenzimidazole and the like can be mentioned.

[0061]

[0062]

[0063]

[0064]

The general formulas (4), (6) and (14)
There is no particular limitation on the salts of the imidazole compound represented by, and various acids such as formic acid, acetic acid, propionic acid, glycolic acid, n-butyric acid, isobutyric acid, acrylic acid, crotonic acid, isocrotonic acid, oxalic acid, and malonic acid , Succinic acid,
Organic acids such as adipic acid, maleic acid, acetylenedicarboxylic acid, monochloroacetic acid, trichloroacetic acid, monobromoacetic acid, tribromoacetic acid, lactic acid, oxybutyric acid, glyceric acid, tartaric acid, malic acid, citric acid, hydrochloric acid, sulfuric acid, nitric acid, phosphorus And salts with inorganic acids such as acids.

The preferable content of the imidazole compound in the surface treating agent of the present invention cannot be specified unconditionally due to solubility in a solvent and the like, but is usually 0.1 to 5.0%.
(% By weight, hereinafter the same).

The general formulas (4), (6) and (14)
The imidazole compound represented by is generally insoluble in water, but can be made into an aqueous solution or aqueous dispersion by using the above-mentioned various acids and a water-soluble solvent in combination.

The surface treating agent of the present invention is an aqueous solution or an aqueous dispersion.
A water-soluble solvent such as isopropyl alcohol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether may be appropriately added.

The surface treating agent of the present invention includes, for example, zinc acetate, zinc hydroxide, zinc sulfide, zinc phosphate, zinc oxide, zinc chloride, and lead acetate in order to improve the film-forming properties and the heat resistance of the film. , Lead hydroxide, iron chloride, iron oxide, copper chloride, copper oxide, copper hydroxide, copper bromide, copper phosphate, copper carbonate, copper acetate, copper sulfate, copper oxalate, copper formate, nickel acetate, nickel sulfide And the like, and various additives conventionally used in surface treatment agents may be added as necessary. Further, the film forming property can be improved by adjusting the acid concentration.

By bringing the surface treating agent of the present invention into contact with copper or a copper alloy, heat resistance and
An organic film excellent in soldering can be formed.

The present invention will be described more specifically with reference to the following examples and comparative examples.

[0072]

Example 1 (Surface treatment agent using compound represented by general formula (4)) 108 g (1 mol) of phenylenediamine and α-naphthale
186 g (1 mol) of acetic acid and 190 g (1 mol) of p-toluenesulfonic acid monohydrate (hereinafter referred to as PTS) were sufficiently mixed, and the temperature was raised to 200 ° C. for 30 minutes with a heating mantle while stirring. And 3 at 200-220 ° C
Heated (substantially no water vapor) for hours. The obtained reaction product was poured into aqueous ammonia, stirred, solidified, washed with water and dried to obtain a purple powder. The obtained powder was recrystallized using a solvent to obtain white needle-like crystals. 0.5 g of the obtained 2- ( α-naphthylmethyl ) benzimidazole was added to a dissolvable amount of acetic acid and dissolved. The obtained solution was added to 100 ml of water to which 0.04 g of cupric chloride was added to prepare a treatment liquid.

A copper plate of 1 cm × 5 cm × 0.3 mm was degreased, washed with water, and then added to a microetching agent (Mec Bright CB-801 manufactured by Mec Co.) at 30 ° C.
The test piece was immersed for 5 minutes and further washed with water to clean the surface. The test piece was immersed in the treatment liquid at 40 ° C. for 1 minute, washed with water, and dried. Then, it was heated in a hot air circulator at 200 ° C. for 10 minutes. Obtained test piece coated with the ultra-low residue type post flux (MEC Co., Ltd. AP-46 26), was solderability test by Meniscograph method. Table 1 shows the test results. It is to be noted that the smaller the value of each of t1 and t2, the better the solder wettability.

[0074]

[0075]

[0076]

[0077]

[0078]

Example 2 (Surface treatment agent using compound represented by general formula (4)) Phenylenediamine, 2-naphthalenepropionic acid and P
2- (α-naphthylethyl) benzimidazole was synthesized in the same manner as in Example 1 using TS. Using the obtained compound, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was performed. Table 1 shows the test results.

Example 3 (Surface treating agent using compound represented by general formula (4)) Using 4-chlorophenylenediamine, α-naphthaleneacetic acid and PTS, 2- (α -Naphthylmethyl) -5-chlorobenzimidazole was synthesized. Using the obtained compound, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was performed. Table 1 shows the test results.

Example 4 (Surface treating agent using compound represented by general formula (4)) Using 4-methylphenylenediamine, α-naphthaleneacetic acid and PTS, 2- (α -Naphthylmethyl) -5-methylbenzimidazole was synthesized. Using the obtained compound, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was performed. Table 1 shows the test results.

Example 5 (Surface treating agent using compound represented by general formula (6)) Using phenylenediamine, 2-thiophenic acid and PTS, 2- (2-thienyl) was obtained in the same manner as in Example 1. Benzimidazole was synthesized. Using the obtained compound, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was performed. Table 1 shows the test results.

[0083]

Example 6 (Surface treating agent using compound represented by general formula (14)) 3,3'-diaminobenzidine and octanoic acid (2 mol)
2,2′-diheptyl-6,5′-dibenzimidazole was synthesized in the same manner as in Example 1 using and PTS. Using the obtained compound, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was performed. Table 1 shows the test results.

Comparative Example 1 Using 2-nonylbenzimidazole, a treatment liquid was prepared in the same manner as in Example 1, and a solder wettability test was conducted. Table 1 shows the test results.

[0086]

[Table 1]

[0087]

The surface treating agent of the present invention has excellent heat resistance,
Very good solderability can be formed on the surface of copper or copper alloy even after exposure to high temperature, so it has a particularly remarkable effect when surface mounting electronic components on printed wiring boards. Things.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Minoru Oya 1 Higashi-Hatsushima-cho, Amagasaki-shi, Hyogo Pref. (72) Inventor Takashi Haruta 1-Higashi-Hatsushima-cho, Amagasaki-shi, Hyogo Mech Co., Ltd. (56 References JP-A-5-263275 (JP, A) JP-A-6-172323 (JP, A) JP-A-6-192851 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB Name) C23C 22/05 C23F 11/00

Claims (1)

(57) [Claims] 1. A compound of the general formula (4): (Where A ¹ is an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, phenylcarbonyl group or halogen atom, A ⁴ is an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, phenylcarbonyl group Or a halogen atom, R ² is an alkylene group, alkenylene group, alkynylene group or arylene group (Arylene), a is an integer of 0 to 4, b is 0 or 1, and c is an integer of 0 to 7.) General formula (6) : (Where d is an integer of 1 to 3, and A ¹ , A ⁴ , R ² , a and b are the same as those described above), or a general formula (1
4): embedded image (Wherein, A ⁸ and A ⁹ are each an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group or a phenylcarbonyl group) or a salt thereof. Surface treatment agent for copper and copper alloys.