JPH07288381A - Pretreatment liquid of through-hole plating using conductive polymer - Google Patents

Abstract

PURPOSE:To provide pretreatment liquid for plating that has good acceleration of generating of manganese dioxide on a glass fabric which enables formation of polymer of good conductivity in a through-hole. CONSTITUTION:This liquid consists of a mixture of anion surfactant containing imidazolinium salt or nonionic surfactant containing polyoxyethylene fatty amide or at least one thereof, and alkaline or acidic water solution containing nonionic surfactant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to through-hole plating of printed wiring boards using a conductive polymer. Regarding processing liquid

[0002]

2. Description of the Related Art When electroplating an inner wall of a through-hole of an insulating substrate, as a means for imparting conductivity to the inner wall of the through-hole in advance, it is not the conventional electroless copper plating, but German Patent P3806884,2-34. As disclosed in US Pat. No. 6,033,963, an organic monomer forming an electrically conductive polymer of an acid polymerization type and a solvent or a solubilizer such as a pyrrole monomer and N-methyl-2-pyrrolidone are used to form an electrically conductive polymer on the inner wall of the through hole. There is a method of forming. Pretreatment for through-hole plating using this conductive polymer is disclosed in JP-A-4-133393 and JP-A-4-18.
As disclosed in Japanese Patent No. 8696, it comprises a soft etching step, a conditioning step, a permanganate treatment step, an organic monomer applying step, and an acid polymerization step,
It is used to form a conductive polymer only on the glass epoxy resin on the inner wall of the through hole and perform electroplating of the through hole later. As a pretreatment liquid for through-hole plating using this conductive polymer, the function of conditioning is to clean dirt on the surface of the object to be processed, such as processing oil, oil on the hands, and other organic substances, and to make it lipophilic. The surface of the plated product is made hydrophilic by a surfactant or the like so that it can be easily wetted and the production of manganese dioxide in a permanganate treatment step which will be performed later is promoted.

[0003]

[Patent Document 1] Japanese Patent Application Laid-Open No. 4-13339
According to the conventional methods disclosed in Japanese Patent Laid-Open No. 3 and Japanese Patent Laid-Open No. 4-188696, the inner wall of the through hole is made conductive, but a through hole having a particularly high plate thickness / hole diameter ratio (hereinafter referred to as an aspect ratio) is used. Sufficient conductivity was not obtained with respect to the substrate which it had, and there was a problem that plating non-precipitation, pinhole voids, etc. sometimes occurred. In order to improve the conductivity of the conductive film formed in the through hole, a method of increasing the treatment time, temperature and concentration of the permanganate treatment step can be considered, but this method not only increases the running cost, It is not preferable because it is dangerous in working and working efficiency is deteriorated.

It is an object of the present invention to provide a pretreatment solution for plating, which is excellent in promoting the production of manganese dioxide on a glass cloth and which makes it possible to form a polymer having good conductivity in through holes. .

[0005]

A pretreatment solution for through-hole plating using a conductive polymer of the present invention is a cationic surfactant containing an imidazolinium salt or a nonionic containing a polyoxyethylene fatty acid amide. It is characterized by comprising an alkaline or acidic aqueous solution containing a mixture or at least one of surfactants and a nonionic surfactant.

The cationic surfactant containing an imidazolinium salt is represented by the general formula

[0007]

[Chemical 4] (However, R: alkyl group R ₁ , R ₂ : alkyl group or alcohol, etc. is selected from X: Cl, Br.) Is preferable.

[0008]

[Chemical 5] Can be used.

Further, the general formula of the nonionic surfactant containing polyoxyethylene fatty acid amide is

[0010]

[Chemical 6] (However, R; alkyl group, R _{1 ,:} C _n H _{2n + 1} NH etc.) are preferable, and specifically,

[0011]

[Chemical 7] Can be used.

Further, as the nonionic surfactant, H.
L. B. (Hydrophile Lipophile Balance) is 1-16
Is good, these are general formulas

[0013]

[Chemical 8] Are preferred, and specifically, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether and the like can be used.

The content of the cationic surfactant containing the imidazolinium salt is preferably 0.1 to 10 g / l, and the content of the nonionic surfactant containing the polyoxyethylene fatty acid amide is 0. 1 to 10 g / l is preferable, and the content of the nonionic surfactant is preferably 0.1 to 50 g / l, and these are used as an alkaline or acidic aqueous solution. If both are below this range, the object of the present invention is not achieved, and above this range, the magnitude of the effect does not change, which is not economical or the effect may be diminished.

[0015]

The pretreatment liquid for plating of the present invention comprises a laminate containing a cation surfactant containing an imidazolinium salt or a nonionic surfactant containing a polyoxyethylene fatty acid amide, or at least one of them. A monomolecular film is formed on the surface of the glass cloth, which is the base material, and is easily oxidized by a permanganic acid step that is performed later, and manganese dioxide is easily generated. Further, it is considered that the nonionic surfactant can improve the wettability of the object to be plated, and an excellent effect is produced by the interaction thereof.

[0016]

【Example】

Example 1 A glass cloth was coated with 1-hydroxyethyl 2-alkyl (hardened beef tallow), a imidazoline quaternary salt, Nissan Cation A.
R-4 (Nippon Oil & Fats Co., Ltd., trade name) 2 g / l and polyoxyethylene octyl phenyl ether HS-
210 (Nippon Yushi Co., Ltd., trade name) p containing 1 g / l
It was treated with a pretreatment solution of an alkaline aqueous solution of H10 at 60 ° C. for 5 minutes. Then, it was treated with an aqueous solution containing 60 g / l of potassium permanganate at 90 ° C. for 5 minutes, and the amount of manganese dioxide produced on the glass cloth was measured. It was found that the larger the amount of manganese dioxide produced, the better the conductivity of the conductive polymer, and the effect was judged by the amount of manganese dioxide produced.

Example 2 Glass cloth was polyoxyethylene polyalkylene polyamine fatty acid amide Labosk 9009 (trade name, manufactured by Toho Chemical Industry Co., Ltd.) 1 g / l, and polyoxyethylene octyl phenyl ether HS-210 (NOF CORPORATION) The product was treated at 60 ° C. for 5 minutes by pretreatment with an acidic aqueous solution of pH 3 containing 10 g / l manufactured by the company. Then, the same treatment as in Example 1 was performed to measure the manganese dioxide on the glass cloth.

Example 3 A glass cloth of polyalkylene polyamine alkyl amide imidazoline acetate Sofnon GW-18 (manufactured by Toho Chemical Industry Co., Ltd., trade name) 5 g / l and polyoxyethylene nonyl phenyl ether HS-220 were used. (Nippon Yushi Co., Ltd., trade name) It was treated at 60 ° C. for 5 minutes with an alkaline aqueous solution containing 5 g / l at pH 10. Then, the same treatment as in Example 1 was performed to measure the manganese dioxide on the glass cloth.

Comparative Example 1 Surfactant Brasolit D without the composition of the above example
NS2 Part 1 (Brasberg, trade name) 15 ml / l
Then, it was treated with the surfactant Brasolit DMS2 Part 2 (manufactured by Brasberg Co., trade name) 30 ml / l at 60 ° C. for 5 minutes. Then, the same treatment as in Example 1 was performed to measure the manganese dioxide on the glass cloth.

The results of Examples 1 to 3 and Comparative Example 1 are shown in Table 1.

[0021]

[Table 1]

As shown in Table 1, those treated with the pretreatment liquids of Examples 1 to 3 produced a large amount of manganese dioxide,
It showed excellent conductivity.

[0023]

As described above, according to the present invention, the production amount of manganese dioxide on the glass cloth can be increased and the conductivity of the conductive polymer formed on the inner wall of the through hole can be improved. It is possible to provide a through-hole plating pretreatment liquid using a conductive polymer that can obtain sufficient conductivity even for a substrate having a high aspect ratio and can suppress the non-precipitation of plating and the generation of pinhole voids.

Claims (2)

[Claims] 1. A cationic surfactant containing an imidazolinium salt or a mixture of nonionic surfactants containing a polyoxyethylene fatty acid amide, or at least one and an alkaline containing a nonionic surfactant. Alternatively, a pretreatment solution for through-hole plating using a conductive polymer characterized by comprising an acidic aqueous solution. 2. A cationic surfactant containing an imidazolinium salt is represented by the general formula: (Provided that R is an alkyl group H R ₁ , R ₂ : an alkyl group or alcohol such as X: Cl, Br, etc.) and contains a polyoxyethylene fatty acid amide. Is represented by the general formula: (wherein R is an alkyl group, R ₁ : C _n H _{2n + 1} NH
Etc.) and the nonionic surfactant is represented by the general formula: RO (CH ₃ CH ₂ O) _n H (provided that R; -C _n H _{2n + 1} , C _n H _{2n + 1-} ). The pretreatment liquid for through-hole plating using the conductive polymer according to claim 1, wherein