KR20090009249A - Metal surface treatment and use of the same - Google Patents

Abstract

A metal surface treatment agent is provided for improving solder wettability to the surface of a metal conductive section constituting a circuit section of a printed wiring board, at the time of soldering an electronic component or the like to the surface of the conductive section. A method for manufacturing a printed wiring board whereupon a chemical film is formed on the surface of a metal conductive section by bringing the surface treatment agent into contact with the surface of the metal conductive section, and a method for manufacturing a printed wiring board to which soldering is performed by using a lead-free solder after forming a chemical film on the surface of a metal conductive section by bringing the surface treatment agent into contact with the surface of the metal conductive section are also provided. The metal surface treatment agent is characterized in containing an imidazole compound and a gluconic compound as effective components.

Description

Metal surface treatment agent and its use {METAL SURFACE TREATMENT AND USE OF THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treating agent used for soldering an electronic component or the like to the surface of a metal conductive portion constituting a circuit portion of a printed wiring board and its use.

In recent years, as a mounting method of a printed wiring board, the surface mounting which improved the mounting density is widely adopted. Such surface mounting methods are divided into double-sided surface mounting in which chip components are joined with cream solder, mixed mounting in which surface mounting with chip solder of chip components and through hole mounting of individual components are combined. In any of the mounting methods, the printed wiring board is soldered a plurality of times, so that the printed wiring board is exposed to a high temperature each time and receives an extreme thermal history.

As a result, since the metal surface, such as copper, a copper alloy, silver, etc. which make up the circuit part of a printed wiring board, is heated, since formation of an oxide film is accelerated | stimulated, the said electrically conductive part It is difficult to maintain good solderability of the surface.

In order to protect such a metal conductive part of a printed wiring board from air oxidation, the surface treatment method which forms the chemical conversion film on the surface of the said conductive part using the antirust agent which uses various imidazole compounds as an active ingredient is proposed (for example, patent Documents 1-4)

By the way, when joining an electronic component to a printed wiring board etc. conventionally, the eutectic solder of a tin-lead alloy was used widely, but in recent years there is concern about the harmfulness to the human body by the lead contained in the solder alloy, and it does not contain lead. It is desired to use solder. Therefore, various lead-free solders have been studied. For example, lead-free solders in which tin is used as a base metal and metals such as silver, zinc, bismuth, indium, antimony and copper have been proposed have been proposed.

The former eutectic solder is excellent in the wettability to the surface of the metal and can be firmly bonded to the metal, thereby achieving high reliability. On the other hand, compared with eutectic solders, the latter lead-free solders have poor wettability with respect to the surface of the metal, and thus have poor solderability and are likely to cause poor bonding, such as void generation, and therefore, weak bonding strength between the metal and the solder. There is a difficulty.

Therefore, in the use of lead-free solders, it is required to select a solder alloy having better solderability and a flux suitable for lead-free solders. The function which improves solderability is calculated | required.

Patent Literature 1: Publication No. 46-17046

Patent Document 2: Japanese Patent Application Laid-Open No. 4-206681

Patent document 3: Unexamined-Japanese-Patent No. 5-25407

Patent Document 4: Japanese Patent Application Laid-Open No. 5-186888

[Problem to Solve Invention]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and, when soldering an electronic component or the like to the surface of a metal conductive portion constituting a circuit portion of a printed wiring board, the surface of the metal which improves the wettability of the solder with respect to the surface of the conductive portion. It is an object to provide a treatment agent.

In addition, a printed wiring board having a chemical conversion film formed on the surface of the metal conductive portion by contacting the surface treating agent with the surface of the metal conductive portion, and a surface formed of the metal conductive portion by contacting the surface treating agent with the surface of the metal conductive portion After forming a film, it aims at providing the manufacturing method of the printed wiring board which solders using a lead-free solder.

[Means for solving the problem]

MEANS TO SOLVE THE PROBLEM As a result of continuing earnest examination in order to solve the said subject, the present inventors found out that it aims at achieving the desired objective by making it the metal surface treating agent containing an imidazole compound and a gluconate compound. The present invention has been completed.

Moreover, 2nd invention contains the imidazole compound in 0.01-10 weight% ratio, and contains a gluconate compound in the ratio of 0.01-50 weight% in 1st invention, The metal surface treating agent characterized by the above-mentioned. to be.

The third invention is a printed wiring board according to the first invention or the second invention, wherein a chemical conversion film is formed on the surface of the metal conductive portion by bringing a metal surface treatment agent into contact with the surface of the metal conductive portion. .

In the fourth invention, in the first invention or the second invention, after forming a chemical film on the surface of the metal conductive portion by contacting the surface treatment agent of the metal with the metal conductive portion, the lead-free solder is used. Soldering is a manufacturing method of the printed wiring board characterized by the above-mentioned.

[effect]

When the surface treatment agent of the metal of this invention uses an imidazole compound and a gluconate compound in combination, when soldering an electronic component etc. to the surface of the metal conductive part which comprises the circuit part of a printed wiring board, it is lead-free solder with respect to the surface of the said conductive part. It is possible to form the chemical conversion film which makes the wettability of the satisfactory. When the printed wiring board of the present invention is used, according to the manufacturing method of the printed wiring board of the present invention, it is possible to ensure the joining of the metal conductive portion and the electronic component by soldering using lead-free solder.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The surface treating agent of this invention is a water-soluble liquid containing an imidazole compound and a gluconic acid compound. Although there is no restriction | limiting in the imidazole compound used in implementation of this invention, For example, the imidazole compound shown by General formula (I)-(VIII) of following General formula (1-8) is used preferably. It is also possible to use a combination of two or more kinds of these imidazole compounds.

(In formula, R <_1> represents the hydrogen atom or the C1-C25 linear or branched alkyl group or alkenyl group which may have a substituent. R <_2> and R <_3> represents a hydrogen atom and a halogen atom. Or a linear or branched alkyl group having 1 to 8 carbon atoms.)

(Wherein, R ₁ represents a hydrogen atom or a linear or branched alkyl or alkenyl group having 1 to 25 carbon atoms which may have a substituent. R ₂ and R ₃ are the same as or different from each other, and R ₂ and R ₃ represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, respectively.)

(In formula, R <_1> represents a hydrogen atom, a halogen atom, or a C1-C17 linear or branched alkyl group. R <_2> , R <_3> , R <_4> and R <_5> are the same or different, and R <_2> , R ₃ , R ₄ and R ₅ each represent a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms.)

In the formula, R ₁ represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 17 carbon atoms. R ₂ , R ₃ , R _4, and R ₅ are the same as or different from each other, and R ₂ , R ₃ , R ₄ and R ₅ each represent a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms.)

(In formula, R <_1> represents a hydrogen atom, a halogen atom, or a C1-C17 linear or branched alkyl group. R <_2> , R <_3> , R <_4> and R <_5> are the same or different, and R <_2> , R ₃ , R ₄ and R ₅ each represent a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms.)

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same as or different from each other, and R ₁ , R ₂ , R ₃ , and R ₄ are each a hydrogen atom, a halogen atom, or a carbon atom having 1 to 8 carbon atoms. Linear or branched alkyl group, n represents an integer of 0-6.)

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same as or different from each other, and R ₁ , R ₂ , R ₃ , and R ₄ are each a hydrogen atom, a halogen atom, or a carbon atom having 1 to 8 carbon atoms. Linear or branched alkyl group, n represents an integer of 0-6.)

(In formula, R <_1> and R <_2> is the same or different, and R <_1> and R <_2> represents a hydrogen atom, a halogen atom, or a C1-C8 linear or branched alkyl group, respectively. N is 0-6 Represents an integer.)

As an imidazole compound represented by General formula (I) of General formula (1),

Imidazole,

2-methylimidazole,

2-ethylimidazole,

2-propylimidazole,

2-isopropylimidazole,

2-butylimidazole,

2-t-butylimidazole,

2-pentylimidazole,

2-hexylimidazole,

2-heptylimidazole,

2- (1-ethylpentyl) imidazole,

2-octylimidazole,

2-nonylimidazole,

2-decylimidazole,

2-undecylimidazole,

2-dodecylimidazole,

2-tridecylimidazole,

2-tetradecylimidazole,

2- pentadecylimidazole,

2-hexadecylimidazole,

2-heptadecylimidazole,

2-octadecylimidazole,

2-nonadesylimidazole,

2-icosanylimidazole,

2-hencosanylimidazole,

2-docosanylimidazole,

2-tricosanilimidazole,

2-tetracosanylimidazole,

2-pentacosanylimidazole,

2- (1-methylpentyl) imidazole,

2- (1-ethylpentyl) imidazole,

2- (1-heptyldecyl) imidazole,

2- (5-hexenyl) imidazole,

2- (9-octenyl) imidazole,

2- (8-heptadecenyl) imidazole,

2- (4-chlorobutyl) imidazole,

2- (9-hydroxynonyl) imidazole,

2-ethyl-4-methylimidazole,

2-undecyl-4-methylimidazole,

2-heptadecyl-4-methylimidazole,

4-methylimidazole,

4-isopropylimidazole,

4-octylimidazole,

2,4,5-trimethylimidazole,

4,5-dimethyl-2-octylimidazole,

2-undecyl-4-methyl-5-bromoimidazole, and

Alkyl imidazole compounds, such as 4, 5- dichloro- 2-ethylimidazole, are illustrated.

As an imidazole compound represented by General formula (II) of General formula (2),

Benzimidazole,

2-methylbenzimidazole,

2-ethylbenzimidazole,

2-propylbenzimidazole,

2-isopropylbenzimidazole,

2-butylbenzimidazole,

2-t-butylbenzimidazole,

2-pentylbenzimidazole,

2-hexylbenzimidazole,

2- (1-methylpentyl) benzimidazole,

2-heptylbenzimidazole,

2- (1-ethylpentyl) benzimidazole,

2-octylbenzimidazole,

2- (2,4,4-trimethylpentyl) benzimidazole,

2-nonylbenzimidazole,

2-decylbenzimidazole,

2-undecylbenzimidazole,

2-dodecylbenzimidazole,

2-tridecylbenzimidazole,

2-tetradecylbenzimidazole,

2-pentadecylbenzimidazole,

2-hexadecylbenzimidazole,

2-heptadecylbenzimidazole,

2- (1-heptyldecyl) benzimidazole,

2-octadecylbenzimidazole,

2-nonadecylbenzimidazole,

2-icosanylbenzimidazole,

2-hencosanylbenzimidazole,

2-docosanylbenzimidazole,

2-tricosanylbenzimidazole,

2-tetracosanylbenzimidazole,

2-pentacosanylbenzimidazole,

2- (8-octylhexadecyl) benzimidazole,

2- (9-octenyl) benzimidazole,

2- (8-heptadecenyl) benzimidazole,

2- (4-chlorobutyl) benzimidazole,

2- (9-hydroxynonyl) benzimidazole,

2-hexyl-5-methylbenzimidazole,

2-heptyl-5,6-dimethylbenzimidazole,

2-octyl-5-chlorobenzimidazole,

2-ethyl-5-octyl-6-bromobenzimidazole,

2-pentyl-5,6-dichlorobenzimidazole,

4-fluorobenzimidazole,

Alkylbenzimidazole compounds, such as 2-pentyl-5-iodine benzimidazole, are illustrated.

As an imidazole compound represented by general formula (III) of General formula (3),

2,4-diphenylimidazole,

2- (2-methylphenyl) -4-phenylimidazole,

2- (3-octylphenyl) -4-phenylimidazole,

2- (2,4-dimethylphenyl) -4-phenylimidazole,

2-phenyl-4- (4-hexylphenyl) imidazole,

2-phenyl-4- (2-methyl-5-butylphenyl) imidazole,

2,4-diphenyl-5-methylimidazole,

2,4-diphenyl-5-hexylimidazole,

2- (2,4-diethyl) -4- (3-propyl-5-octyl) -5-isobutylimidazole,

2- (2-chlorophenyl) -4-phenylimidazole,

2- (3-chlorophenyl) -4-phenylimidazole,

2- (4-chlorophenyl) -4-phenylimidazole,

2- (2-bromophenyl) -4-phenylimidazole,

2- (3-bromophenyl) -4-phenylimidazole,

2- (4-bromophenyl) -4-phenylimidazole,

2- (2-iodinephenyl) -4-phenylimidazole,

2- (3-iodinephenyl) -4-phenylimidazole,

2- (4-iodinephenyl) -4-phenylimidazole,

2- (2-fluorophenyl) -4-phenylimidazole,

2- (3-fluorophenyl) -4-phenylimidazole,

2- (4-fluorophenyl) -4-phenylimidazole,

2- (2,3-dichlorophenyl) -4-phenylimidazole,

2- (2,4-dichlorophenyl) -4-phenylimidazole,

2- (2,5-dichlorophenyl) -4-phenylimidazole,

2- (2,6-dichlorophenyl) -4-phenylimidazole,

2- (3,4-dichlorophenyl) -4-phenylimidazole,

2- (3,5-dichlorophenyl) -4-phenylimidazole,

2- (2,4-dibromophenyl) -4-phenylimidazole,

2- (2-methyl-4-chlorophenyl) -4-phenylimidazole,

2- (3-bromo-5-octylphenyl) -4-phenylimidazole,

2- (2-chlorophenyl) -4-phenyl-5-methylimidazole,

2- (3-chlorophenyl) -4-phenyl-5-methylimidazole,

2- (4-chlorophenyl) -4-phenyl-5-methylimidazole,

2- (2-bromophenyl) -4-phenyl-5-methylimidazole,

2- (3-bromophenyl) -4-phenyl-5-methylimidazole,

2- (4-bromophenyl) -4-phenyl-5-methylimidazole,

2- (2-iodinephenyl) -4-phenyl-5-methylimidazole,

2- (3-iodinephenyl) -4-phenyl-5-methylimidazole,

2- (4-iodinephenyl) -4-phenyl-5-methylimidazole,

2- (2-fluorophenyl) -4-phenyl-5-methylimidazole,

2- (3-fluorophenyl) -4-phenyl-5-methylimidazole,

2- (4-fluorophenyl) -4-phenyl-5-methylimidazole,

2- (2,3-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (2,4-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (2,5-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (2,6-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (3,4-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (3,5-dichlorophenyl) -4-phenyl-5-methylimidazole,

2- (2,4-dichlorophenyl) -4-phenyl-5-ethylimidazole,

2- (2,3-dichlorophenyl) -4-phenyl-5-decylimidazole,

2- (3,4-dichlorophenyl) -4-phenyl-5-heptadecylimidazole,

2- (2,4-dibromophenyl) -4-phenyl-5-isopropylimidazole,

2- (2-heptyl-4-chlorophenyl) -4-phenyl-5-isobutylimidazole,

2-phenyl-4- (2-chlorophenyl) imidazole,

2-phenyl-4- (3-chlorophenyl) imidazole,

2-phenyl-4- (4-chlorophenyl) imidazole,

2-phenyl-4- (2-bromophenyl) imidazole,

2-phenyl-4- (3-bromophenyl) imidazole,

2-phenyl-4- (4-bromophenyl) imidazole,

2-phenyl-4- (2-iodinephenyl) imidazole,

2-phenyl-4- (3-iodinephenyl) imidazole,

2-phenyl-4- (4-iodinephenyl) imidazole,

2-phenyl-4- (2-fluorophenyl) imidazole,

2-phenyl-4- (3-fluorophenyl) imidazole,

2-phenyl-4- (4-fluorophenyl) imidazole,

2-phenyl-4- (2,3-dichlorophenyl) imidazole,

2-phenyl-4- (2,4-dichlorophenyl) imidazole,

2-phenyl-4- (2,5-dichlorophenyl) imidazole,

2-phenyl-4- (2,6-dichlorophenyl) imidazole,

2-phenyl-4- (3,4-dichlorophenyl) imidazole,

2-phenyl-4- (3,5-dichlorophenyl) imidazole,

2-phenyl-4- (2,3-dibromophenyl) imidazole,

2-phenyl-4- (2-propyl-3-chlorophenyl) imidazole,

2-phenyl-4- (3-bromo-4-heptylphenyl) imidazole,

2-phenyl-4- (2-chlorophenyl) -5-methylimidazole,

2-phenyl-4- (3-chlorophenyl) -5-methylimidazole,

2-phenyl-4- (4-chlorophenyl) -5-methylimidazole,

2-phenyl-4- (2-bromophenyl) -5-methylimidazole,

2-phenyl-4- (3-bromophenyl) -5-methylimidazole,

2-phenyl-4- (4-bromophenyl) -5-methylimidazole,

2-phenyl-4- (2-iodinephenyl) -5-methylimidazole,

2-phenyl-4- (3-iodinephenyl) -5-methylimidazole,

2-phenyl-4- (4-iodinephenyl) -5-methylimidazole,

2-phenyl-4- (2-fluorophenyl) -5-methylimidazole,

2-phenyl-4- (3-fluorophenyl) -5-methylimidazole,

2-phenyl-4- (4-fluorophenyl) -5-methylimidazole,

2-phenyl-4- (2,3-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (2,4-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (2,5-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (2,6-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (3,4-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (3,5-dichlorophenyl) -5-methylimidazole,

2-phenyl-4- (2,3-dichlorophenyl) -5-propylimidazole,

2-phenyl-4- (2,4-dichlorophenyl) -5-undecylimidazole,

2-phenyl-4- (2,4-dibromophenyl) -5- (1-methylbutyl) imidazole,

2-phenyl-4- (2-hexyl-4-iodinephenyl) -5-propylimidazole,

2,4-bis (4-chlorophenyl) imidazole,

2- (2,4-dichlorophenyl) -4- (3,4-dichlorophenyl) -5-methylimidazole,

2- (2-bromo-4-octylphenyl) -4- (2-methyl-4-iodinephenyl) -5-octylimidazole,

2,4-diphenyl-5-fluoroimidazole,

2,4-diphenyl-5-chloroimidazole,

2,4-diphenyl-5-bromoimidazole,

2,4-diphenyl-5-iomidimidazole,

2- (4-methylphenyl) -4-phenyl-5-chloroimidazole,

2- (4-chlorophenyl) -4-phenyl-5-bromoimidazole,

2-phenyl-4- (2-chlorophenyl) -5-iodiimidazole and the like are exemplified.

As an imidazole compound represented by general formula (IV) of General formula (4),

2-phenyl-4- (1-naphthyl) imidazole,

2-phenyl-4- (2-naphthyl) imidazole,

2- (4-methylphenyl) -4- (4-chloro-6-butyl-1-naphthyl) imidazole,

2- (2-octyl-4-ethylphenyl) -4- (5-chloro-7-heptyl-1-naphthyl) imidazole,

2- (2,4-dichlorophenyl) -4- (2-isobutyl-6-bromo-2-naphthyl) imidazole,

2-phenyl-4- (1-naphthyl) -5-methylimidazole,

2- (4-iodinephenyl) -4- (5,6-dimethyl-1-naphthyl) -5-decylimidazole,

2-phenyl-4- (2-naphthyl) -5-methylimidazole,

2- (2,3-difluorophenyl) -4- (7-octyl-2-naphthyl) -5-heptadecylimidazole,

2-phenyl-4- (1-naphthyl) -5-fluoroimidazole,

2-phenyl-4- (1-naphthyl) -5-chloroimidazole,

2-phenyl-4- (1-naphthyl) -5-bromoimidazole,

2-phenyl-4- (1-naphthyl) -5-iodiimidazole,

2-phenyl-4- (2-naphthyl) -5-fluoroimidazole,

2-phenyl-4- (2-naphthyl) -5-chloroimidazole,

2-phenyl-4- (2-naphthyl) -5-bromoimidazole,

2-phenyl-4- (2-naphthyl) -5-iodiimidazole,

2- (4-methylphenyl) -4- (5-chloro-1-naphthyl) -5-chloroimidazole and the like are exemplified.

As an imidazole compound represented by General formula (V) of General formula (5),

2- (1-naphthyl) -4-phenylimidazole,

2- (2-naphthyl) -4-phenylimidazole,

2- (2-methyl-5-chloro-1-naphthyl) -4- (4-hexylphenyl) imidazole,

2- (2-isobutyl-5-iodine-2-naphthyl) -4- (2-pentyl-5-fluorophenyl) imidazole,

2- (1-naphthyl) -4-phenyl-5-methylimidazole,

2- (3,6-dichloro-2-naphthyl) -4- (2-isopropyl-5-fluorophenyl) -5-decylimidazole,

2- (6-propyl-7-iodine-1-naphthyl) -4- (3-hexyl-6-bromophenyl) -5-heptadecylimidazole,

2- (1-naphthyl) -4-phenyl-5-fluoroimidazole,

2- (1-naphthyl) -4-phenyl-5-chloroimidazole,

2- (1-naphthyl) -4-phenyl-5-bromoimidazole,

2- (1-naphthyl) -4-phenyl-5-iodiimidazole,

2- (2-naphthyl) -4-phenyl-5-fluoroimidazole,

2- (2-naphthyl) -4-phenyl-5-chloroimidazole,

2- (2-naphthyl) -4-phenyl-5-bromoimidazole,

2- (2-naphthyl) -4-phenyl-5-iodiimidazole,

2- (4-chloro-2-naphthyl) -4- (2-hexylphenyl) -5-chloroimidazole and the like are exemplified.

As an imidazole compound represented by general formula (VI) of General formula (6),

2-phenylbenzimidazole,

2- (4-methylphenyl) benzimidazole,

2- (2,4-dichlorophenyl) benzimidazole,

2- (2-hexylphenyl) -5-chlorobenzimidazole,

2- (phenylmethyl) benzimidazole,

2- (4-ethylphenylmethyl) benzimidazole,

2- (4-chlorophenylmethyl) benzimidazole,

2- (2,4-dichlorophenylmethyl) benzimidazole,

2- (3,4-dichlorophenylmethyl) benzimidazole,

2- (4-bromophenylmethyl) -5-ethylbenzimidazole,

2- (3-iodinephenylmethyl) -4-chlorobenzimidazole,

2- (2-phenylethyl) benzimidazole,

2- [2- (3-isopropylphenyl) ethyl] benzimidazole,

2- [2- (4-chlorophenyl) ethyl] benzimidazole,

2- [2- (4-chlorophenyl) ethyl] -4,5-dimethylbenzimidazole,

2- (3-phenylpropyl) benzimidazole,

2- [3- (4-t-butylphenyl) propyl] benzimidazole,

2- [3- (2-chlorophenyl) propyl] benzimidazole,

2- [3- (4-bromophenyl) propyl] -5-butylbenzimidazole,

2- (4-phenylbutyl) benzimidazole,

2- [4- (4-chlorophenyl) butyl] benzimidazole,

2- [4- (2,4-dichlorophenyl) butyl] -4,7-dichlorobenzimidazole,

2- (5-phenylpentyl) benzimidazole,

2- [5- (2-octylphenyl) pentyl] benzimidazole,

2- [5- (3,4-dichlorophenyl) pentyl] -5-heptylbenzimidazole,

2- (6-phenylhexyl) benzimidazole,

2- [6- (3-hexylphenyl) hexyl] benzimidazole,

2- [6- (2-ethyl-3-fluorophenyl) hexyl] -4-butyl-5-octylbenzimidazole and the like are exemplified.

As an imidazole compound represented by General formula (VII) of General formula (7),

2- (1-naphthyl) benzimidazole,

2- (1-naphthyl) -4-methylbenzimidazole,

2- (2-naphthyl) benzimidazole,

2- (1-chloro-2-naphthyl) -5,6-dichlorobenzimidazole,

2- (1-naphthylmethyl) benzimidazole,

2- (4,6-dimethyl-1-naphthylmethyl) -5-ethylbenzimidazole,

2- (7-bromo-1-naphthylmethyl) -5-bromobenzimidazole,

2- (2-naphthylmethyl) benzimidazole,

2- (4-isopropyl-2-naphthylmethyl) -5-t-butylbenzimidazole,

2- [2- (1-naphthyl) ethyl] benzimidazole,

2- [2- (5-pentyl-1-naphthyl) ethyl] -5-chlorobenzimidazole,

2- [2- (2-naphthyl) ethyl] benzimidazole,

2- [2- (6-heptyl-2-naphthyl) ethyl] -4-methyl-5-hexylbenzimidazole,

2- [3- (1-naphthyl) propyl] benzimidazole,

2- [3- (4-iodine-1-naphthyl) propyl] -5,6-dibromobenzimidazole,

2- [3- (2-naphthyl) propyl] benzimidazole,

2- [3- (8-isopropyl-2-naphthyl) propyl] -5- (2-methylpentyl) benzimidazole,

2- [4- (1-naphthyl) butyl] benzimidazole,

2- [4- (5-fluoro-1-naphthyl) butyl] -4- (2-propylbutyl) benzimidazole,

2- [4- (2-naphthyl) butyl] benzimidazole,

2- [4- (7-octyl-2-naphthyl) butyl] -4,6-diethylbenzimidazole,

2- [5- (1-naphthyl) pentyl] benzimidazole,

2- [5- (6-pentyl-7-fluoro-1-naphthyl) pentyl] -4,7-dipropylbenzimidazole,

2- [5- (2-naphthyl) pentyl] benzimidazole,

2- [5- (6,7-dimethyl-2-naphthyl) pentyl] -5,6-dichlorobenzimidazole,

2- [6- (6,7-diethyl-1-naphthyl) hexyl] -5-octylbenzimidazole,

2- [6- (2-naphthyl) hexyl] benzimidazole,

2- [6- (7-ethyl-8-bromo-2-naphthyl) hexyl] -4-hexyl-6-fluorobenzimidazole and the like are exemplified.

As an imidazole compound represented by General formula (VIII) of Formula (8),

2-cyclohexylbenzimidazole,

2-cyclohexyl-5,6-dimethylbenzimidazole,

2-cyclohexyl-5-chlorobenzimidazole,

2-cyclohexyl-4-isopropylbenzimidazole,

2- (cyclohexylmethyl) benzimidazole,

2- (cyclohexylmethyl) -5-ethylbenzimidazole,

2- (cyclohexylmethyl) -5-bromobenzimidazole,

2- (2-cyclohexylethyl) benzimidazole,

2- (2-cyclohexylethyl) -5-chloro-6-methylbenzimidazole,

2- (3-cyclohexylpropyl) benzimidazole,

2- (3-cyclohexylpropyl) -5-butylbenzimidazole,

2- (3-cyclohexylpropyl) -4,7-dimethylbenzimidazole,

2- (4-cyclohexylbutyl) benzimidazole,

2- (4-cyclohexylbutyl) -5-iodinebenzimidazole,

2- (4-cyclohexylbutyl) -4-chloro-5-ethylbenzimidazole,

2- (4-cyclohexylbutyl) -5-octylbenzimidazole,

2- (5-cyclohexylpentyl) benzimidazole,

2- (5-cyclohexylpentyl) -5-hexylbenzimidazole,

2- (5-cyclohexylpentyl) -5,6-dibromobenzimidazole,

2- (6-cyclohexylhexyl) benzimidazole,

2- (6-cyclohexylhexyl) -5-heptylbenzimidazole,

2- (6-cyclohexylhexyl) -4-chloro-5- (2-propylbutyl) benzimidazole and the like are exemplified.

In the practice of the present invention, these imidazole compounds may be contained in a ratio of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, in the surface treating agent. If the content rate of the imidazole compound is less than 0.01% by weight, the thickness of the chemical conversion film formed on the metal surface becomes thin, and the oxidation of the metal surface cannot be sufficiently prevented. In addition, when the content ratio of the compound of the imidazole compound is more than 10% by weight, it is difficult to control the surface treatment for obtaining a desired thickness suitable for the soldering conditions.

The gluconic acid compound used in the practice of the present invention is gluconic acid or its ammonium salt and metal salt having a structural formula represented by the following formula (9). Examples of the ammonium salt of gluconic acid include amine salts such as ammonium gluconate, trimethylammonium gluconate, and triethanol ammonium gluconate. Examples of the metal salt of gluconic acid include sodium gluconate, zinc gluconate, iron gluconate, aluminum gluconate, and the like.

These gluconate compounds should just be contained in the ratio of 0.01-50 weight% in a surface treating agent, Preferably it is 0.1-30 weight%. When the content rate of the gluconic acid compound is less than 0.01% by weight, the effect of improving the solder wettability is not sufficient, and even if it is more than 50% by weight, an increase in the effect of improving the solder wettability is not expected.

Gluconic acid compounds are known to have a coordination effect (chelating properties) on metals, but the imidazole compounds form complexes on the surface of metals, and are aggregated and deposited by intermolecular bonds to form a chemical coating. It is thought that when forming a, it exerts some effect.

In carrying out the present invention, in the aqueous solution of the imidazole compound, it is possible to use a conventionally known organic acid, inorganic acid or organic solvent as a solubilizer.

Representative organic substances used in this case include formic acid, acetic acid, propionic acid, butyric acid, glyoxylic acid, pyrvinic acid, acetoacetic acid, levrinic acid, heptanoic acid, caprylic acid, capric acid, lauryl acid, glycolic acid, and glycerin acid. , Lactic acid (lactic acid), acrylic acid, benzoic acid, paranitrobenzoic acid, paratoluene sulfonic acid, methane sulfonic acid, satritylic acid, picric acid, oxalic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, adipic acid, and the like, and hydrochloric acid, phosphoric acid, Sulfuric acid, nitric acid and the like.

As the organic acid, a carboxylic acid compound represented by the general formula (10) may be used.

In the formula, R ₁ represents a linear or branched alkyl group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom or a methyl group. M represents an integer of 0 to 3, and n represents 1 or 2 .)

These acid compounds can be used individually or in combination, It is good to contain in the ratio of 0.1-50 weight%, Preferably it is 1-30 weight% in a surface treating agent. When the content ratio of the acid compound is less than 0.1% by weight, it is not possible to sufficiently solubilize the imidazole compound, and even if it is more than 50% by weight, an increase in the solubilization effect of the imidazole compound cannot be expected. The drug cost of the compound is only increased.

Examples of the organic solvent include lower alcohols such as methanol, ethanol, and isopropyl alcohol, which are freely mixed with water, or acetone, N, N-dimethylformamide, ethylene glycol, and the like.

It is possible to add a copper compound to the surface treatment agent of the present invention in order to speed up the formation rate of the chemical conversion film on the surface of the metal conductive portion, and also to add a zinc compound to further improve the heat resistance of the formed chemical conversion film. good.

Typical examples of the copper compound include copper acetate, cuprous chloride, cupric chloride, cuprous bromide, cuprous bromide, copper iodide, copper hydroxide, copper phosphate, copper sulfate, copper nitrate, and the like. Representative examples of the zinc compound include zinc oxide, zinc hydrochloride, zinc bromide, zinc iodide, zinc formate, zinc acetate, zinc oxalate, lactic acid (lactic acid) zinc, zinc citrate, zinc sulfate, zinc nitrate, zinc phosphate, and the like. Any of these may be contained in a ratio of 0.01 to 10% by weight, preferably 0.02 to 5% by weight, in the surface treating agent.

In the case of using these copper compounds or zinc compounds, it is preferable to add a substance having a buffering effect such as ammonia or amines such as monoethanolamine, diethanolamine, and triethanolamine to stabilize the pH of the surface treating agent in the surface treating agent. desirable.

In the surface treating agent of the present invention, in order to further improve the formation rate of the chemical conversion film and the heat resistance of the film, it is possible to contain the halogen compound at a ratio of 0.001 to 1% by weight, preferably 0.01 to 0.5% by weight. As a halogen compound, sodium fluoride, potassium fluoride, ammonium fluoride, sodium chloride, potassium chloride, ammonium chloride, sodium bromide, potassium bromide, ammonium bromide, sodium iodide, potassium iodide, ammonium iodide, etc. are mentioned, for example.

As conditions for processing the surface of the metal conductive part of a printed wiring board using the surface treating agent of this invention, it is preferable to make the liquid temperature of a surface treating agent into 10 to 70 degreeC, and to make contact time into 1 second-10 minutes. As a contact method, methods, such as immersion, spraying, application | coating, are mentioned.

In addition, after the surface treatment of the present invention, it is also possible to form a double structure of a thermoplastic resin on the chemical conversion film to further increase the heat resistance.

That is, after forming a chemical film on the surface of a metal conductive part, rosin derivatives, such as rosin and rosin ester, terpine resin derivatives, such as terpene resin and terpene phenol resin, aromatic hydrocarbon resin, and aliphatic The thermoplastic resin which is excellent in heat resistance which consists of hydrocarbon resins, such as a hydrocarbon resin, and mixtures thereof is melt | dissolved in solvents, such as toluene, ethyl acetate, and isopropyl alcohol, and the film thickness is 1-30 micrometers on a chemical conversion film with a roll coater etc. What is necessary is just to apply | coat uniformly and to form the double structure of a chemical film and a thermoplastic resin.

As a soldering method obtained by adapting to the present invention, for example, a flow method of flowing a printed wiring board onto a solder bath containing a hot melted liquid solder and soldering to a junction portion between the electronic component and the printed wiring board or in advance. A reflow method is described in which a paste-like cream solder is printed on a printed wiring board in accordance with a circuit pattern, an electronic component is mounted thereon, the printed wiring board is heated to melt the solder, and soldering is performed.

Examples of the solder applied to the soldering of the present invention include lead-free solders such as Sn-Ag-Cu, Sn-Ag-Bi, Sn-Bi, Sn-Ag-Bi-In, Sn-Zn, and Sn-Cu. Although enumerated, the eutectic solder of the tin-lead alloy conventionally used can also be used.

Example

Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these. In addition, the raw material used by the Example and the comparative example and the evaluation test method are as follows. For raw materials not described, commercial reagents were used.

[Imidazole Compound]

2,4-diphenyl-5-methylimidazole (synthesized according to the method described in Japanese Patent Application Laid-Open No. 7-243053)

2- (2,4-dichlorophenyl) -4-phenyl-5-methylimidazole (synthesized according to the method described in Japanese Patent Application Laid-Open No. 2004-277386)

2-phenyl-4- (3,4-dichlorophenyl) imidazole (synthesized according to the method described in JP-A 2005-104878)

2- (1-naphthyl) -4-phenyl-5-methylimidazole (synthesized according to the method described in JP 2006-36683)

2-phenyl-4- (2-naphthyl) imidazole (synthesized according to the method described in Japanese Patent Application Laid-Open No. 2006-36683)

2- (4-chlorophenylmethyl) benzimidazole (synthesized according to the method described in Science of Synthetics, 12 , 529 (2002))

2- (1-naphthylmethyl) benzimidazole (synthesized according to the method described in Biochemical Pharmacology, 36 , 463 (1987)).

[Gluconic acid compound]

Gluconic acid (50% aqueous solution, reagent made by Wako Pure Chemical Industries, Ltd.)

[Evaluation test of solder synergism]

As a test piece, the printed wiring board of the glass epoxy resin of 120 mm (length) x 150 mm (width) x 1.6 mm (thickness) which has 300 copper conduction holes of 0.80 mm inside diameter was used. After degreasing, soft etching, and washing the test piece, the test piece was immersed in a surface treatment agent well maintained at a predetermined liquid temperature for a predetermined time, and then a chemical film having a thickness of about 0.10 to 0.50 µm was formed on a washed and dried copper surface. I was.

The test piece subjected to the surface treatment was subjected to three times of reflow heating with a peak temperature of 245 ° C using an infrared reflow apparatus (product name: MULTI-PRO-306, manufactured by Vitronix), followed by a flow soldering apparatus. Soldering was carried out using (conveyor speed: 1.0 m / min).

The solder used was lead-free solder (commercial name: H705 [eco solder], made by Senzukinjok Co., Ltd.) having a composition of 96.5 tin-3.0 silver-0.5 copper (% by weight), and the flux used during soldering was JS-E-. 09 (made by footjob). Moreover, soldering temperature was 245 degreeC.

With respect to the test piece to be soldered, the number of the through holes in which the solder was raised (soldered) to the upper land portion of the copper through holes was measured, and the ratio (%) to the total number of through holes (300) was calculated. .

The greater the wettability of the solder with respect to the surface of copper, the more likely the molten solder penetrates into the copper through hole and rises to the upper land portion of the through hole. That is, as the ratio of the number of the through-holes where the solder rises to the upper land portion with respect to the total number of the through-holes is large, the wettability of the solder to the copper is excellent and the solderability is judged to be good.

[Evaluation Test of Solder Spreadability]

As a test piece, a printed wiring board made of glass epoxy resin of 50 mm (length) x 50 mm (width) x 1.2 mm (thickness) (as a circuit pattern, a conductor width of 0.80 mm made of copper foil and a circuit part having a length of 20 mm is 1.0 mm apart. 10 formed articles in the width direction in the After degreasing, soft etching, and washing with water, the test piece was immersed in a surface treatment agent well preserved at a predetermined temperature for a predetermined time, and then a chemical film having a thickness of about 0.10 to 0.50 µm was formed on a washed and dried copper surface. .

Reflow heating with a peak temperature of 245 degreeC was performed once about the test piece which processed this surface using the infrared reflow apparatus (product name: MULTI-PRO-306, the product made by Vitronix). Thereafter, a cream solder was printed on the center of the copper circuit portion using a metal mask having an opening diameter of 1.2 mm and a thickness of 150 mu m, reflow heating was performed under the previous conditions, and soldering was performed. Moreover, the cream solder used is a lead-free solder (brand name: M705-221BM5-42-11, a product made by Senjukinjok Co., Ltd.) which consists of 96.5 tin-3.0 silver-0.5 copper (weight%).

About the obtained test piece, the length (mm) of the solder spread | diffused on the surface of the copper circuit part was measured.

The larger this length, the better the wettability of the solder and the better the solderability.

Example 1

2,4-diphenyl-5-methylimidazole as the imidazole compound, acetic acid and gluconic acid as the solubilizer, copper acetate as the metal salt, and ammonium iodide as the halogen compound, so as to have the composition shown in Table 1, respectively. After dissolving in, it was adjusted to pH 3.6 in ammonia water to prepare a surface treatment agent.

Subsequently, the test piece of the printed wiring board was immersed for 60 seconds in the aqueous solution preflux adjusted to 40 degreeC, and then washed with water and dried, and the synergism of solder and the spreadability of the solder were measured. These test results were as showing in Table 1.

[Examples 2-9, Comparative Examples 1-9]

In the same aspect as in Example 1, a surface treatment agent having a composition and pH shown in Table 1 was prepared, the surface treatment was performed under the treatment conditions shown in Table 1, and an evaluation test was carried out. The test results obtained are as shown in Table 1.

Although this invention was detailed also demonstrated with reference to the specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention.

This application is based on the JP Patent application (Japanese Patent Application No. 2006-140229) of an application on May 19, 2006, The content is taken in here as a reference.

According to the present invention, when soldering an electronic component or the like to the surface of a metal conductive portion constituting a circuit portion of a printed wiring board, it is possible to provide a metal surface treatment agent which has good wettability of solder to the surface of the conductive portion.

Further, according to the present invention, a printed wiring board having a chemical conversion film formed on the surface of the metal conductive portion by contacting the surface treating agent with the surface of the metal conductive portion, and a metal made by contacting the surface treating agent with the surface of the metal conductive portion After forming the chemical conversion film on the surface of the conductive portion, it is possible to provide a method for producing a printed wiring board which is soldered using lead-free solder.

Claims (4)

An imidazole compound and a gluconic acid compound are contained, The surface treating agent of the metal characterized by the above-mentioned. The method of claim 1, An imidazole compound is contained in a ratio of 0.01 to 10% by weight, and a gluconic acid compound is contained in a ratio of 0.01 to 50% by weight. A chemical conversion film is formed on the surface of a metal conductive part by making the surface treating agent of the metal of Claim 1 or 2 contact on the surface of a metal conductive part. By contacting the surface of the metal conductive part with the surface treating agent of the metal of Claim 1 or 2, after forming a chemical film on the surface of a metal conductive part, soldering is performed using lead-free solder, The manufacture of the printed wiring board characterized by the above-mentioned. Way.