KR0142407B1 - Process for production of copper through-hole printed wiring boards - Google Patents

Abstract

An etching resist layer is formed on the copper plating of the double-sided copper clad laminate to produce a copper perforated printed wiring board. The etch resist layer applies a negative resist pattern on both sides of the laminate, and then laminates the salts of 2-alkylbenzimidazole, 2-alkylalkylbenzimidazole, 2-phenylbenzimidazole and 2-phenylalkylbenzimidazole. It is formed by immersion in a solution containing one or more. After the obtained etching resist layer is selectively removed with an aqueous alkali solution, the exposed copper plating is etched with an alkali etchant according to a predetermined pattern of wiring. According to the method of the present invention, significant advantages can be obtained in the production of copper perforated printed wiring boards such as improved productivity, low manufacturing cost, reduction of toxic substances in waste water and high certainty.

Description

Manufacturing method of copper perforated printed wiring board

The present invention relates to a method of manufacturing a printed wiring board having a copper through-hole, that is, a copper perforated printed wiring board. According to this method, printed wiring boards can be manufactured with much increased certainty at low production costs in a short production time.

Copper perforated printed wiring boards have the advantage that all circuits, including perforations, are made of copper, so that the solder resist adheres well and the etching resist is completely removed from the circuit area. Such printed wiring boards are typically manufactured according to the following three methods.

(1) hole-filling method;

(2) tenting method; And

(3) Solder Separation Method

The hole method consists of drilling a required number of holes in a predetermined portion of a double-sided copper clad laminate, and sequentially performing chemical copper plating and copper electroplating on the perforated laminate. After the electroplating is completed, all the holes are filled with sealing ink to prevent the etchant from entering each punch in the subsequent etching step. Thereafter, a positive resist pattern corresponding to the required circuit pattern is applied to both sides of the laminate by a printing process or a photographic process, and then etching is performed using the resist pattern as a mask to remove the copper exposed by the resist pattern. Finally, the resist pattern and sealing ink in the hole are removed to obtain the desired copper perforated printed wiring board.

The tenting method is characterized by using a dry resist film instead of the sealing ink of the above-mentioned hole method. That is, after completion of perforation, chemical copper plating and copper electroplating, a dry resist film is attached to both sides of the laminate and the pores are covered with the film. The resist film is exposed and developed pattern by pattern, and then the exposed copper is removed by etching using the remaining resist film as a mask. It can be seen that the inner wall (copper plating) of the perforation is protected by upper and lower resist films. After removing the remaining resist film, a copper perforated printed wiring board is obtained.

Solder separation is distinguished from the methods described above in that it uses a negative pattern of plating resist for solder electroplating (resist is not etched). This method does not require sealing ink. After punching, chemical copper plating and copper electroplating are completed as in the above two methods, and the negative pattern of the plating resist is applied to the copper-clad laminate by printing or photolithography. The solder is then attached to the exposed copper surface by performing solder electroplating using the negative resist pattern as a mask. Next, the resist pattern used as the mask and the exposed copper plating without solder are removed to obtain a copper perforated printed wiring board.

However, the conventional method discussed above has several disadvantages. For example, defective products are frequently produced due to the low certainty of the etch resist layer used, and therefore the production cost is notably high but the production cost is remarkably high. In particular, these methods do not meet the recent demand for large quantities of products to be provided at low cost within a short supply time. In addition, in the solder separation method, the problem of environmental pollution cannot be avoided because of the hydrofluoric acid and lead used in the processing step, and thus the cost for preventing environmental pollution is significantly increased.

It is an object of the present invention to provide a new method for the production of copper perforated printed wiring boards which ensures the manufacture of wiring boards comparable to or higher than the solder separation method and which is completed in a simple and short processing time. In addition, from the viewpoint of environmental pollution prevention, the treatment of waste water is also simple and the manufacturing cost of the feeder wiring board is cheap compared with the conventional method.

According to the invention,

Negative patterns of an aqueous alkali solution-soluble resist are formed on both sides of the copper-clad laminate having the pre-punched holes according to a printing process or a photographic process;

The resist pattern-containing copper-clad laminate is immersed in a bath of a solution giving an etching resist layer and containing at least one salt of a compound represented by the following formulas (I) and (II) or a derivative thereof as an active ingredient, The copper plating surface of the laminate is covered with an etching resist layer consisting of copper complexes of the compounds of (I) and / or (II)

(Wherein R ₁ is an alkyl group having 3 to 17 carbon atoms, R ₂ represents a lower alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, n is an integer of 0 to 3, and HA represents an organic or inorganic acid.)

(Wherein R ₃ and R ₄ are the same or different and each represents a lower alkyl group, preferably an alkyl group having 1 to 6 carbon atoms such as methyl, R ₅ represents an alkyl group having 0 to 7 carbon atoms, and n and HA are each As defined above);

After drying the etch resist layer of the laminate,

Treating the laminate with an aqueous alkaline solution to selectively remove the etch resist layer to expose copper plating in the non-circuit region of the laminate;

A method of manufacturing a copper perforated printed wiring board is provided, which comprises treating a laminate with an alkaline etchant to etch copper plating exposed from the laminate.

In the compound of formula (II), when the carbon number of the alkyl group R ₅ is 0, the compound is represented by the following formula.

According to the present invention, there is also provided a variant of the above method, further comprising immersing the copper-clad laminate in a buffer solution containing copper ions after formation of the etching resist layer and prior to its selective removal.

The present inventors thoroughly investigated various materials in order to find a novel manufacturing method of the printed wiring board and materials useful for such a method, and as a result, 2-alkyl-benzimidazole, 2-alkylalkylbenzimidazole, 2-phenylbenzimidazole and It has been found that 2-phenylalkylbenzimidazoles, ie the compounds represented by the formulas (I) and / or (II) above, are useful as active ingredients in solutions providing the etching resist layer in the above-described method. These benzimidazole compounds are more stable and more economical than solders and can be more easily removed from copper deposited laminates as needed. In addition, these compounds are excellent in corrosion resistance and can protect the copper plated portion of the laminate during the alkali etching process. Moreover, these compounds are excellent in reactivity with copper, so that the etching resist layer can be selectively deposited only on the copper surface of the laminate.

Typical examples of benzimidazole compounds (I) and (II) used in the process of the present invention include the following:

B-1-1 2-n-propylbenzimidazole,

BI-2 2-n-propylmetalbenzimidazole,

BI-3 2-n-propyldimethylbenzimidazole,

B-1-4 2-n-butylbenzimidazole,

BI-5 2-n-butylmethylbenzimidazole,

Bi-6-n-butyldimethylbenzimidazole,

BI-7 2-n-pentylbenzimidazole,

BI-8 2-n-pentylmethylbenzimidazole,

BI-9 2-n-pentyldimethylbenzimidazole,

BI-10 2-n-hexylbenzimidazole,

BI-11 2-n-hexylmethylbenzimidazole,

BI-12 2-n-hexyldimethylbenzimidazole,

BI-13 2-n-heptylbenzimidazole,

Bi-14-n-heptylmethylbenzimidazole,

BI-15 2-n-heptyldimethylbenzimidazole,

BI-16 2-n-octylbenzimidazole,

BI-17 2-n-octylmethylbenzimidazole,

BI-18 2-n-octyldimethylbenzimidazole,

BI-19 2-n-nonylbenzimidazole,

BI-20 2-n-nonylmethylbenzimidazole,

BI-21 2-n-nonyldimethylbenzimidazole,

BI-22 2-n-decylbenzimidazole,

BI-23 2-n-decylmethylbenzimidazole,

BI-24 2-n-decyldimethylbenzimidazole,

BI-25 2-n-undecylbenzimidazole,

BI-26 2-n-undecylmethylbenzimidazole,

BI-27 2-n-undecyldimethylbenzimidazole,

BI-28 2-n-dodecylbenzimidazole,

BI-29 2-n-dodecylmethylbenzimidazole,

BI-30 2-n-dodecyldimethylbenzimidazole,

BI-31 2-n-tridecylbenzimidazole,

BI-32 2-n-tridecylmethylbenzimidazole,

BI-33 2-n-tridecyldimethylbenzimidazole,

BI-34 2-n-tetradecylbenzimidazole,

Bi-35 2-n-tetradecylmethylbenzimidazole,

BI-36 2-n-tetradecyldimethylbenzimidazole,

BI-37 2-n-pentadecylbenzimidazole,

BI-38 2-n-pentadecylmethylbenzimidazole,

BI-39 2-n-pentadecyldimethylbenzimidazole,

BI-40 2-n-hexadecylbenzimidazole,

BI-41 2-n-hexadecylmethylbenzimidazole,

BI-42 2-n-hexadecyldimethylbenzimidazole,

BI-43 2-n-heptadecylbenzimidazole,

BI-44 2-n-heptadecylmethylbenzimidazole,

BI-45 2-n-heptadecyldimethylbenzimidazole,

BI-46 2-isopropylbenzimidazole,

BI-47 2-isopropylmethylbenzimidazole,

BI-48 2-isopropyldimethylbenzimidazole,

BI-49 2-isobutylbenzimidazole,

BI-50 2-isobutylmethylbenzimidazole,

BI-51 2-isobutyldimethylbenzimidazole,

BI-52 2-isopentylbenzimidazole,

BI-53 2-isopentylmethylbenzimidazole,

BI-54 2-isopentyldimethylbenzimidazole,

BI-55 2-isohexylbenzimidazole,

BI-56 2-isohexylmethylbenzimidazole,

BI-57 2-isohexyldimethylbenzimidazole,

BI-58 2-neopentylbenzimidazole,

BI-59 2-neopentylmethylbenzimidazole,

BI-60 2-neopentyldimethylbenzimidazole,

BI-61 2-sec-butylbenzimidazole,

BI-62 2-sec-butylmethylbenzimidazole,

BI-63 2-sec-butyldimethylbenzimidazole,

BI-64 2-t-butylbenzimidazole,

BI-65 2-t-butylmethylbenzimidazole,

BI-66 2-t-butyldimethylbenzimidazole,

BI-67 2-phenylbenzimidazole,

BI-68 2-phenylmethylbenzimidazole,

BI-69 2-phenyldimethylbenzimidazole,

BI-70 2-tosylbenzimidazole,

BI-71 2-tosylmethylbenzimidazole,

BI-72 2-tosyldimethylbenzimidazole,

BI-73 2-xylylbenzimidazole,

BI-74 2-xylylmethylbenzimidazole,

BI-75 2-xylyldimethylbenzimidazole,

BI-76 2-mesitylbenzimidazole,

BI-77 2-methylmethylbenzimidazole,

BI-78 2-methyldimethylbenzimidazole,

BI-79 2-t-phenylbenzimidazole,

BI-80 2-t-phenylmethylbenzimidazole,

BI-81 2-t-phenyldimethylbenzimidazole,

BI-82 2- (1-phenylmethyl) benzimidazole,

BI-83 2- (3-phenylpropyl) benzimidazole,

BI-84 2- (7-phenylheptyl) benzimidazole,

BI-85 2- (2-phenylethyl) methylimidazole,

BI-86 2- (2-tolylethyl) benzimidazole, and

BI-87 2- (2-tolylethyl) benzimidazole.

In the practice of the present invention, these benzimidazole compounds may be used alone or in a mixture of two or more compounds. As mentioned above, these compounds may be used in the form of their derivatives as necessary. Also, in the solution providing the etching resist layer, these compounds are used as salts of organic or inorganic acids. Typical examples of suitable acids include acetic acid, formic acid, capric acid, glycolic acid, p-nitrobenzoic acid, p-toluenesulfonic acid, picric acid, oxalic acid, succinic acid, phosphorous acid, maleic acid, acrylic acid, fumaric acid, tartaric acid, adipic acid, hydrochloric acid, Sulfuric acid, phosphoric acid, lactic acid, oleic acid and the like.

In addition, the solution providing the etching resist layer may be any amount of a metal compound, such as copper (II) acetate, copper (II) sulfate, cuprous chloride, cupric chloride, cupric hydroxide, cuprous oxide, cuprous oxide, cuprous phosphate ( II) and copper carbonate, and water-soluble solvents such as methanol, ethanol, isopropyl alcohol, butanol and acetone. The preparation of the etch resist layer-providing solution is described below.

The production method of the present invention may be carried out according to the following process sequence, but may be added to the usual additional process if necessary.

(1) A negative resist pattern is formed on a copper clad laminate.

(2) The laminate is immersed in the etching resist layer-providing solution.

(3) The etching resist layer is dried.

(4) The etching resist layer is selectively removed.

(5) Copper plating is etched.

In addition, a buffer treatment step can be introduced between steps (2) and (3).

In the first step of this process, the negative pattern of the alkaline aqueous solution-soluble resist is attached to both sides of the copper-clad laminate according to a printing process or a photographic process such as screen printing. Ordinary copper-clad laminates containing a substrate with copper foil on its upper and lower surfaces are used. Laminates include both rigid and flexible plates. In addition, the copper-clad laminate used here has a predetermined number of perforations, and copper foil is also provided on the inner surface of each perforation. Copper foil or plating is generally produced by chemical copper plating and copper electroplating. Prior to the formation of the resist pattern, copper plating of the double-sided copper clad laminate is treated and surface-finished to improve its surface properties. The treatment and finishing processes include, for example, soft etching, polishing, swabbing, liquid honing ( honing), degreasing and washing with water.

Preferably, the negative pattern of the aqueous alkali solution-soluble resist is formed from, for example, resist ink, alkali-developable liquid resist and alkali-developable photosensitive film or dry film resist. The printing process or photographic process is selected depending on the type of resist used.

After formation of the negative resist pattern, the resist pattern-containing copper-clad laminate is immersed in an etching resist layer-providing solution containing at least one salt of the benzimidazole compounds (I) and (II) described above. Preferably, the immersion solution used is a benzimidazole compound, i.e. 2-alkylbenzimidazole, 2-alkylalkylbenzimidazole, 2-phenylbenzimidazole or 2-phenylalkylbenzimidazole, with respect to the total amount of the solution. It is contained in an amount of 0.01 to 40%, preferably 0.1 to 5%. Preferably, immersion is carried out at a temperature of from 0 to 100 ° C, more preferably from 30 to 50 ° C. Immersion times can vary widely from seconds to tens of minutes; For example, an immersion time at a temperature of 40 to 50 ° C. is suitable for 1 to 3 minutes. In addition, the immersion solution preferably has a pH value of the acidic side, and more preferably has a pH value of 5.0 or less. Note that the amount of resist layer deposited on the copper plating can be increased with increasing the immersion temperature and prolonging the immersion time.

The etching resist layer thus obtained is dried. Drying can be carried out by any conventional method such as a drying oven.

Moreover, according to another aspect of the present invention, the etching resist layer may be treated with a copper ion-containing buffer solution. It is preferable to immerse the etching resist layer-containing laminate in the buffer solution. One or more bases such as ammonia, diethylamine, triethylamine, diethanolamine, triethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, isopropylethanolamine, sodium hydroxide and potassium hydroxide and copper acetate (II ), Copper (II) sulfate, cuprous chloride, cupric chloride, copper hydroxide, copper oxide, cuprous oxide, cuprous oxide, copper phosphate (II) and copper carbonate (I) Buffers can be prepared. Preferably, the copper ion concentration in the buffer solution is at least several ppm, more preferably from 50 to 150 ppm and the pH value of the buffer solution is preferably from 6.5 to 4.5. Immersion is carried out at a temperature of 0 to 100 ° C, preferably 30 to 50 ° C. The immersion time can vary widely from a few seconds to several tens of minutes, but the immersion time is preferably 1 to 3 minutes.

After complete drying, the etch resist layer is selectively removed to expose the copper plating in the non-circuit region of the laminate. Selective removal of the etch resist layer is preferably performed by contacting the laminate with an aqueous alkali solution, more preferably using dipping and spraying during this treatment. After selective removal of the etch resist layer, alkali etching is used to etch the exposed copper plating (unnecessary portion) from the laminate. During this process, any known alkali etchant may be used in the alkali etching system in a conventional manner. After removing the resist layer used as the mask, the desired copper perforated printed wiring board can be obtained.

The detailed mechanism of the process is not yet clear, but this is because the described 2-alkylbenzimidazole, 2-alkylalkylbenzimidazole, 2-phenylbenzimidazole and 2-phenylalkylbenzimidazole each have film forming ability and thus It is based on the finding that the layers formed from these benzimidazole compounds can be used industrially as chemically stable corrosion resistant resist layers.

In addition, the benzimidazole compound may chemically react with copper of copper plating to form a stable chelate monomolecular film. Chelated monomolecular films can increase their film thickness over time. Moreover, benzimidazole compounds are deposited on copper plating due to the van der Waals forces of their adjacent alkyl groups to form a net-like layer. It should be noted that when the buffer treatment described above is carried out after the formation of the benzimidazole layer, copper ions in the buffer migrate to the benzimidazole layer, resulting in an excellent improvement in the stability of the layer, ie the chelate monomolecular film. The physical strength of the layer can be increased significantly.

The present invention will be further described with reference to Examples.

[Examples 1 and 2]

A predetermined number of holes are drilled by drilling a double-sided copper clad laminate FR-4 having a thickness of 1.6 mm. Chemical copper plating and copper electroplating are performed annually to deposit 25-30 μm thick copper plating on the inner surface of each perforation and on both sides of the laminate. After copper plating is formed, the negative pattern of the resist is coated onto the copper plating of the laminate according to the printing process (Example 1) and the photographic process (Example 2).

For Example 1, a resist ink (trade name KM-10, manufactured by Taiyo Ink Seizo K K) whose main components were acrylic acid and styrene copolymer was printed on the laminated copper plating on the screen printing machine. The negative pattern of the resulting resist, about 20 μm thick, is dried at 80 ° C. for 10 minutes.

For Example 2, a photosensitive dry film resist (trade name: A-225, manufactured by Fuji Hunt Co.) was juxtaposed onto the copper plating of the laminate and exposed and developed as shown in the photograph. The negative pattern of the resulting resist having a thickness of 25 mu m was dried as in Example 1.

The resist pattern-containing copper-clad laminate is immersed in 20% aqueous sodium persulfate solution (persulfate etchant) to soft etch the surface of the copper plating. After soft etching, the copper-clad laminate was immersed in a 1% solution of the benzimidazole compound shown in Table 1 containing 0.5 g / l of formic acid and ammonia as well as cupric chloride, and the laminate was treated at 50 ° C. for 3 minutes while moving the laminate slowly. do. After the benzimidazole treatment is complete, the copper-clad laminate is washed with water and dried at 140 ° C. for 10 minutes. In this way, an etching resist layer is obtained.

After forming the etch resist layer, the resist layer-containing laminate is treated with 3% aqueous sodium hydroxide solution to selectively remove the resist layer in the non-circuit region. As a result, the copper plating on the non-circuit area of the laminate is completely exposed.

The copper-clad laminate is etched with an alkaline etchant (trade name: A process, manufactured by Mertec Co.) by inducing the laminate through an etchant spray at 50 ° C. for 120 seconds. The exposed copper plating is etched away completely. The laminate is immersed in a 5% aqueous hydrochloric acid solution to remove the etching resist layer used as the shielding means in the previous etching step. In this way, a copper perforated printed wiring board is obtained. The wiring board was evaluated with respect to the finished state and the evaluation results are summarized in Table 1 below.

EXAMPLES 3 AND 4

A predetermined number of holes are drilled by drilling a double-sided copper clad laminate FR-4 having a thickness of 1.6 mm. Chemical copper plating and copper electroplating are performed annually to deposit 25-30 μm thick copper plating on the inner surface of each perforation and on both sides of the laminate. After the copper plating is formed, the negative pattern of the resist is coated onto the copper plating of the laminate according to the printing process (Example 3) and the photographic process (Example 4).

For Example 3, a resist ink (trade name KM-10, manufactured by Taiyo Ink Seizo K K) whose main components were acrylic acid and styrene copolymer was printed on the laminated copper plating on the screen printing machine. The negative pattern of the resulting resist, about 20 μm thick, is dried at 80 ° C. for 10 minutes.

For Example 4, a photosensitive dry film resist (trade name: A-225, manufactured by Fuji Hunt Co.) was juxtaposed onto the copper plating of the laminate, and then exposed and developed as shown in the photograph. The negative pattern of the resulting resist, 25 μm thick, was dried as in Example 3.

The resist pattern-containing copper-clad laminate is immersed in 20% aqueous sodium persulfate solution (persulfate etchant) to soft etch the surface of the copper plating. After soft etching, the copper-clad laminate was immersed in a 1% solution of the benzimidazole compound shown in Table 1 containing 0.5 g / l of formic acid and ammonia as well as cupric chloride, and the laminate was treated at 50 ° C. for 3 minutes while moving the laminate slowly. do. After the benzimidazole treatment is complete, the copper-clad laminate is washed with water and dried at 140 ° C. for 10 minutes. In this way, an etching resist layer is obtained.

After forming the etch resist layer, the resist layer-containing laminate is treated with 3% aqueous sodium hydroxide solution to selectively remove the resist layer in the non-circuit region. As a result, the copper plating on the non-circuit area of the laminate is completely exposed.

The copper-clad laminate is etched with an alkaline etchant (trade name: A process, manufactured by Mertec Co.) by inducing the laminate through an etchant spray at 50 ° C. for 120 seconds. The exposed copper plating is etched away completely. The laminate is immersed in a 5% aqueous hydrochloric acid solution to remove the etching resist layer used as the shielding means in the previous etching step. In this way, a copper perforated printed wiring board is obtained. The wiring board was evaluated with respect to the finished state and the evaluation results are summarized in Table 2 below.

[Examples 5 and 6]

A predetermined number of holes are drilled by drilling a double-sided copper clad laminate FR-4 having a thickness of 1.6 mm. Chemical copper plating and copper electroplating are performed annually to deposit 25-30 μm thick copper plating on the inner surface of each perforation and on both sides of the laminate. After copper plating is formed, the negative pattern of the resist is coated onto the copper plating of the laminate according to the printing process (Example 5) and the photographic process (Example 6).

For Example 5, a resist ink (trade name KM-10, manufactured by Taiyo Ink Seizo K K) having main components acrylic acid and styrene copolymer was printed on the laminated copper plating on the screen printing machine. The negative pattern of the resulting resist, about 20 μm thick, is dried at 80 ° C. for 10 minutes.

For Example 6, a photosensitive dry film resist (trade name: A-225, manufactured by Fuji Hunt Co.) was juxtaposed onto the copper plating of the laminate and exposed and developed as shown in the photograph. The negative pattern of the resulting resist, 25 μm thick, was dried as in Example 5.

The resist pattern-containing copper-clad laminate is immersed in 20% aqueous sodium persulfate solution (persulfate etchant) to soft etch the surface of the copper plating. After soft etching, the copper-clad laminate was immersed in a 1% solution of the benzimidazole compound shown in Table 1 containing 0.5 g / l of formic acid and ammonia as well as cupric chloride, and the laminate was treated at 50 ° C. for 3 minutes while moving the laminate slowly. do.

The benzimidazole treatment is terminated and then treated with buffer to further enhance the effect of benzimidazole treatment. The copper-clad laminate is washed with water and then immersed for 2 minutes at 50 ° C. in copper ion-containing buffer. The buffer solution used here is an aqueous solution (pH 5.2) containing 0.1 g / l copper chloride in addition to formic acid and ammonia. The copper clad laminate is washed with water and dried at 140 ° C. for 10 minutes. In this way, an etching resist layer is obtained.

After forming the etch resist layer, the resist layer-containing laminate is treated with 3% aqueous sodium hydroxide solution to selectively remove the resist layer in the non-circuit region. As a result, the copper plating on the non-circuit area of the laminate is completely exposed.

The copper-clad laminate is etched with an alkaline etchant (trade name: A process, manufactured by Mertec Co.) by inducing the laminate through an etchant spray at 50 ° C. for 120 seconds. The exposed copper plating is etched away completely. The laminate is immersed in a 5% aqueous hydrochloric acid solution to remove the etching resist layer used as the shielding means in the previous etching step. In this way, a copper perforated printed wiring board is obtained. The wiring board was evaluated with respect to the finished state and the evaluation results are summarized in Table 1 below. It is pointed out that the finish state of the wiring board is significantly improved as compared with that of Examples 1 and 2.

EXAMPLES 7 AND 8

A predetermined number of holes are drilled by drilling a double-sided copper clad laminate FR-4 having a thickness of 1.6 mm. Chemical copper plating and copper electroplating are performed annually to deposit 25-30 μm thick copper plating on the inner surface of each perforation and on both sides of the laminate. After copper plating is formed, the negative pattern of the resist is coated onto the copper plating of the laminate according to the printing process (Example 7) and the photographic process (Example 8).

For Example 7, a resist ink (trade name KM-10, manufactured by Taiyo Ink Seizo K K) having main components acrylic acid and styrene copolymer was printed on the laminated copper plating on the screen printing machine. The negative pattern of the resulting resist, about 20 μm thick, is dried at 80 ° C. for 10 minutes.

For Example 8, a photosensitive dry film resist (trade name: A-225, manufactured by Fuji Hunt Co.) was juxtaposed onto the copper plating of the laminate and exposed and developed as shown in the photograph. The negative pattern of the resulting resist, 25 μm thick, was dried as in Example 7.

The resist pattern-containing copper-clad laminate is immersed in 20% aqueous sodium persulfate solution (persulfate etchant) to soft etch the surface of the copper plating. After soft etching, the copper-clad laminate was immersed in a 1% solution of the benzimidazole compound shown in Table 2 containing 0.5 g / l of formic acid and ammonia as well as cupric chloride, and the laminate was treated at 50 ° C. for 3 minutes while moving the laminate slowly. do.

The benzimidazole treatment is terminated and then treated with buffer to further enhance the effect of benzimidazole treatment. The copper-clad laminate is washed with water and then immersed for 2 minutes at 50 ° C. in copper ion-containing buffer. The buffer solution used here is an aqueous solution (pH 5.2) containing 0.1 g / l copper chloride in addition to formic acid and ammonia. The copper clad laminate is washed with water and dried at 140 ° C. for 10 minutes. In this way, an etching resist layer is obtained.

After forming the etch resist layer, the resist layer-containing laminate is treated with 3% aqueous sodium hydroxide solution to selectively remove the resist layer in the non-circuit region. As a result, the copper plating on the non-circuit area of the laminate is completely exposed.

The copper-clad laminate is etched with an alkaline etchant (trade name: A process, manufactured by Mertec Co.) by inducing the laminate through an etchant spray at 50 ° C. for 120 seconds. The exposed copper plating is etched away completely. The laminate is immersed in a 5% aqueous hydrochloric acid solution to remove the etching resist layer used as the shielding means in the previous etching step. In this way, a copper perforated printed wiring board is obtained. The wiring board was evaluated with respect to the finished state and the evaluation results are summarized in Table 2 below. It is pointed out that the finish state of the wiring board is significantly improved as compared with that of Examples 3 and 4.

Claims (11)

Negative patterns of an aqueous alkali solution-soluble resist are formed on both sides of the copper-clad laminate having the pre-punched holes according to a printing process or a photographic process; The resist pattern-containing copper-clad laminate is immersed in a solution bath that provides an etching resist layer and contains at least one salt of a compound represented by the following formulas (I) and (II) or a derivative thereof as an active ingredient, The copper plating surface of the laminate is covered with an etching resist layer consisting of a copper complex of a compound of formula (II), a compound of formula (II), or a mixture thereof (Wherein R ₁ is an alkyl group having 3 to 17 carbon atoms, R ₂ represents a lower alkyl group, n is an integer of 0 to 3, and HA represents an organic or inorganic acid.) (Wherein R ₃ and R ₄ are the same or different and each represents a lower alkyl group, R ₅ represents an alkyl group having 0 to 7 carbon atoms, and n and HA are each as defined above); Drying the etch resist layer of the laminate and then treating the laminate with an aqueous alkali solution to selectively remove the etch resist layer to expose copper plating in the non-circuit region of the laminate; A method of manufacturing a copper perforated printed wiring board, comprising treating a laminate with an alkaline etchant to etch copper plating exposed from the laminate. The method of claim 1, further comprising immersing the etching resist layer-containing copper deposited laminate in a buffer containing copper ions after formation of the etching resist layer and prior to its selective removal. The method of claim 1 or 2, wherein the negative resist pattern is formed from an aqueous alkali solution-soluble resist ink. The method of claim 1 or 2, wherein the negative resist pattern is formed from an alkali-developable liquid resist. The method of claim 1, wherein the negative resist pattern is formed from an alkali-developable resist film. The 2-alkylbenzimidazole, 2-alkylalkylbenzimidazole, 2-phenylbenzimidazole, or 2-phenylalkylbenzimidazole compound of Claim 1 or 2 represented by Formula (I) or Formula (II). 2-N-propylbenzimidazole, 2-n-propylmethylbenzimidazole, 2-n-propyldimethylbenzimidazole, 2-n-butylbenzimidazole, 2-n-butylmethylbenzimidazole, 2 -n-butyldimethylbenzimidazole, 2-n-pentylbenzimidazole, 2-n-pentylmethylbenzimidazole, 2-n-pentyldimethylbenzimidazole, 2-n-hexylbenzimidazole, 2-n -Hexylmethylbenzimidazole, 2-n-hexyldimethylbenzimidazole, 2-n-heptylbenzimidazole, 2-n-heptylmethylbenzimidazole, 2-n-heptyldimethylbenzimidazole, 2-n- Octylbenzimidazole, 2-n-octylmethylbenzimidazole, 2-n-octyldimethylbenzimidazole, 2-n-nonylbenzimidazole, 2-n-nonylmethylbenzimidazole, 2-n-nonyldimethyl Benzimidazole, 2-n-decylbenzimidazole, 2-n-decyl Tilbenzimidazole, 2-n-decyldimethylbenzimidazole, 2-n-undecylbenzimidazole, 2-n-undecylmethylbenzimidazole, 2-n-undecyldimethylbenzimidazole, 2-n Dodecylbenzimidazole, 2-n-dodecylmethylbenzimidazole, 2-n-dodecyldimethylbenzimidazole, 2-n-tridecylbenzimidazole, 2-n-tridecylmethylbenzimidazole, 2-n-tridecyldimethylbenzimidazole, 2-n-tetradecylmethylbenzimidazole, 2-n-tetradecylmethylbenzimidazole, 2-n-tetradecyldimethylbenzimidazole, 2-n-pentadidecylbenz Imidazole, 2-n-pentadecylmethylbenzimidazole, 2-n-pentadecyldimethylbenzimidazole, 2-n-hexadecylbenzimidazole, 2-n-hexadecylmethylbenzimidazole, 2-n- Hexadecyldimethylbenzimidazole, 2-n-heptadecylbenzimidazole, 2-n-heptadecylmethylbenzimidazole, 2-n-heptadecyldimethylbenzimidazole, 2-n-isopropylbenzimidazole, 2 -n-isopropylmethylbenzimidazole, 2 -n-isopropyldimethylbenzimidazole, 2-n-isobutylbenzimidazole, 2-n-isobutylmethylbenzimidazole, 2-n-isobutyldimethylbenzimidazole, 2-n-isopentylbenzimidazole Dazole, 2-n-isopentylmethylbenzimidazole, 2-n-isopentyldimethylbenzimidazole, 2-n-isohexylbenzimidazole, 2-n-isohexylmethylbenzimidazole, 2-n-iso Hexyldimethylbenzimidazole, 2-n-neopentylbenzimidazole, 2-n-neopentylmethylbenzimidazole, 2-sec-butylbenzimidazole, 2-sec-butylmethylbenzimidazole, 2-sec- Butyldimethylbenzimidazole, 2-t-butylbenzimidazole, 2-t-butylmethylbenzimidazole, 2-t-butyldimethylbenzimidazole, 2-phenylbenzimidazole, 2-phenylmethylbenzimidazole, 2-phenyldimethylbenzimidazole, 2-tosylbenzimidazole, 2-tosylmethylbenzimidazole, 2-tosyldimethylbenzimidazole, 2-xylylbenzimidazole, 2-xylylmethylbenzimidazole, 2- Xylyldimethylbene Imidazole, 2-methylbenzimidazole, 2-methylmethylbenzimidazole, 2-methyldimethylbenzimidazole, 2-t-phenylbenzimidazole, 2-t-phenylmethylbenzimidazole, 2- t-phenyldimethylbenzimidazole. The method according to claim 1 or 2, wherein the benzidazole compound represented by formula (I) or formula (II) is used in an amount of 0.01 to 40% in a solution providing an etching resist layer. The method of claim 1 or 2, wherein the copper-clad laminate is immersed in a solution bath providing an etch resist layer for 1 to 3 minutes at a bath temperature of 40 to 50 ° C. The method of claim 2 wherein the copper ion-containing buffer solution is ammonia, dimethylamine, triethylamine, diethanolamine, triethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, isopropylethanolamine, sodium hydroxide and At least one base selected from the group consisting of potassium hydroxide; And copper (II) acetate, copper (II) sulfate, cuprous chloride, cupric chloride, copper hydroxide, copper oxide, cuprous oxide, cuprous oxide, copper (II) phosphate and copper carbonate (I). A method containing at least one copper compound. The method of claim 2 or 9, wherein the concentration of copper ions in the buffer solution is 50 ~ 150ppm. The method according to claim 2 or 9, wherein the buffer treatment is carried out at a bath temperature of 30 to 50 ° C for 1 to 3 minutes.