JP2778323B2 - Printed wiring board and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board and a method of manufacturing the same, and more particularly to a high-density printed wiring board suitable for increasing the density of conductive circuits and improving the reliability of through holes, and a method of manufacturing the same. The present invention relates to a photocurable resist composition used.

[0002]

2. Description of the Related Art Next, (1) to (6) will be described as conventional examples.

(1) Conventional Example 1 FIG. 5 is a partial cross-sectional perspective view showing the appearance of a typical example of a conventional printed wiring board. As shown in the drawing, in the through hole 2 of the printed wiring board formed only by the copper plating 7, the peel strength is low due to the tensile peel strength test, so that a blister is formed on the inner wall of the through hole 2 during various pretreatment steps. No. 15 is likely to occur, resulting in an accident such as poor connection, and there is a problem in reliability of the through hole. In addition, a circuit pattern made of copper plating and a through-hole conductor are coated with nickel plating to form a two-layer structure of copper plating and nickel plating.
This cannot solve the above problem. Japanese Patent Application Laid-Open No. Sho 62-190792 discloses a conductor having a copper-nickel two-layer structure of this type.

(2) Conventional Example 2 For example, a method of forming a circuit on a high-density printed circuit board having a small-diameter through hole having a diameter of 0.5 mm or less requires a solder plating as shown in FIG. The method is commonly used. Hereinafter, description will be made with reference to FIG. 8 which shows a schematic view of a circuit forming step by a solder plating method.

Step (a): A hole is formed in the copper-clad laminate 1 and copper plating is performed to form a through hole 2.

Step (b): A film type photoresist 11 is laminated on the entire surface of the substrate, and is exposed 10 using a positive type mask 12 on which a circuit pattern is drawn.

Step (c): developing the photoresist 11
Is formed.

Step (d): Solder plating 13 is performed.

Step (e): The plating resist 14 is peeled off,
The underlying copper is exposed.

Step (f): The exposed copper is removed by etching using the solder plating 13 as a resist mask.

Step (g): The circuit pattern 9 is formed by removing the resist mask of the solder plating 13.

(3) Conventional Example 3 A well-known example in which the inner peripheral surface of the through hole has a double structure of nickel and copper is described in JP-A-1-313996. Are different, and there are the following two differences.

While the present application is a multilayer board including an inner layer circuit pattern, the above-mentioned known example is a double-sided board not including an inner layer circuit pattern.

The copper foil forming the through-holes and the lands is formed by chemical copper plating in the present application, but is formed by electrolytic copper plating in the above-mentioned known example. (Deposition shape, strength, etc. are different between chemical copper plating and electrolytic copper plating, and the former is more accurate, more reliable and allows through-hole formation.) (4) Conventional example 4 Formed using only conventional copper foil In the circuit pattern on the surface layer, there are the following two problems in increasing the density of the pattern.

When the pattern becomes thin, the copper pattern surface 9
There is a concern that the adhesion of the solder resist 6 covering the solder resist becomes insufficient and the solder resist peels off 20 after copper plating or soldering. (FIG. 14) When the pattern gap becomes narrow, electrolytic corrosion (outflow due to ionization of the conductive metal) occurs between the copper patterns due to slight moisture absorption of the solder resist or the like, and there is a concern that insulation failure may occur.
The mechanism of the electrolytic corrosion will be described with reference to FIG. 15. If there is a potential difference between the conductor patterns 9 and the insulating solder resist 6 contains moisture or an electrolyte, the copper ions Cu ionized on the + side gradually become negative. As they are pulled, they eventually lead to dielectric breakdown.

(5) Conventional Example 5 Even when the inner layer circuit pattern and the inner layer through holes (inner vias, surface vias) of the conventional multilayer board are formed only of copper foil, if the pattern gap becomes narrow, a small amount of the base material may be formed. Electric erosion is likely to occur due to excessive moisture absorption or ionic foreign matter, and there is a concern that insulation failure may occur.

(6) After forming a circuit of the prior art, a solder resist is also formed on the circuit, and a special function is required for the solder resist used in the part-reactive method in which through holes can be connected by chemical copper plating. Is done. That is, a high temperature, a strong alkali immersion in a harsh chemical copper plating solution for a long time, and the deposition potential of the chemical copper plating on the copper wiring pattern under the solder resist −0.6 to
-0.9V (see saturated calomel electrode) works for a long time. Even after such a severe process, it is an extremely advanced function that must not degrade any properties such as heat resistance required as a solder resist and insulation properties necessary to protect a printed circuit board as a permanent resist. .

As a solder resist having plating resistance suitable for this purpose, an epoxy resin-based thermosetting type which forms a pattern by screen printing is known, and an example thereof is disclosed in JP-A-58-147416. Is disclosed. In addition, a UV exposure and development type solder resist having plating resistance is also known.
-265321. UV exposure and development type solder resists having such plating resistance are available in U
Since the pattern is formed by V exposure and development, the accuracy is extremely high, and it is suitable for manufacturing a high-density printed circuit board. However, in mass production of plating a large number of printed circuit boards, since dicyandiamide is included in the components of the resist,
In a long-time chemical copper plating process, a small amount of dicyandiamide dissolves in the chemical copper plating solution, which has a serious effect on the deposition state of the copper plating, thereby deteriorating the reliability of the through hole.

[0019]

Problems to be Solved by the Invention (1) Conventional Example-1,2
However, in the circuit pattern forming method described with reference to FIG. 8, the conventional film-type photosensitive resist 11 is not suitable for forming a fine pattern (resolution of 50 μm or less).
As shown in FIG. 7A, a resist resolution defect 23 occurs,
There is a problem that adjacent resist patterns 11 are docked or a poor resist adhesion 24 occurs, and it has been difficult to form a high-density circuit.

On the other hand, there is a method using an electrodeposition type photosensitive resist to form a high-resolution fine line pattern. When an electrodeposition type photosensitive resist is used, as shown in FIG. 9 (b), the film thickness is smaller than that of a film type photosensitive resist and the adhesion to the copper foil surface is good, so that a high resolution fine line pattern can be formed. is there. However, in this type of pattern forming step, the inner wall of the through hole 2 must also be exposed, and in the small diameter through hole, as shown in FIG. Exposure in 1
It is difficult to irradiate sufficient light to 0, and there are portions that are not partially exposed. Therefore, as shown in step (c) of FIG. 6, a defect 8a occurs in the electrodeposition type photosensitive resist mask 8 in the through hole 2 formed by exposure and development.
In the etching process using the defect mask 8a, FIG.
Since the through-hole defect 7a is generated as shown in FIG. 4D, the reliability of the through-hole is reduced.

A method for forming a high-resolution fine line pattern without impairing the reliability of through holes is disclosed in
No. 47090, the electrodeposition resist is used as a solder plating resist, and since the solder plating resist pattern serves as an etching resist for the conductive film, the etching accuracy is different from that of the conventional solder plating method shown in FIG. Absent. That is, in the method of forming a circuit pattern using the electrodeposition resist, an electrodeposition resist is used instead of the photoresist 11 in the step (b) of FIG.

Therefore, an object of the present invention is to solve the problems pointed out in the above-mentioned prior art examples 1 and 2, and a first object of the present invention is to improve the reliability of the conductor layer in the through-hole and obtain a high-resolution fine wire. It is an object of the present invention to provide an improved high-density printed circuit board capable of realizing a pattern, and a second object thereof.

(2) Problems of Conventional Examples -4 and 5 The limit value when the circuit gap is narrowed with a pattern of only copper foil is 120 to 130 μm, which will be a problem when the density is further increased in the future. .

(3) Problems of Conventional Example-6 Further, the present invention realizes a UV exposure and development type solder resist having plating resistance which does not have the drawbacks of the above-described conventional technology, and realizes a high density printed circuit board. It is to make manufacturing easier. The characteristics to be provided as a practical resist are various, and if any one of them is missing, the practicality is significantly impaired. Therefore, the object of the present invention can be solved by manufacturing a high-density printed circuit board using a resist satisfying many characteristics at the same time, which cannot be realized only by the combination of the conventional techniques. The resist characteristics required for this purpose are listed as follows.

A) It is essential that the resist of the present invention does not contain dicyandiamide. In mass production of plating a large amount of printed circuit boards, if dicyandiamide is included in the resist components, a small amount of dicyandiamide will dissolve in the chemical copper plating solution in the long-time chemical copper plating process, and the copper plating precipitates. It has a profound effect and degrades the reliability of the through hole. Therefore, the resist of the present invention must satisfy the following problems without containing dicyandiamide.

B) The resist of the present invention must be cured by exposure to UV light. That is, 300 to 400 nm UV light (ultraviolet light) suitable for manufacturing a printed circuit board.
Irradiation causes a crosslinking reaction, and only the irradiated portion needs to be cured. In addition, a practical 0.02
It is desirable to cure in the range of 10 J / cm ² .

C) It is essential that the resist of the present invention has an appropriate difference in solubility in a developing solution between a portion cured by UV irradiation and an uncured portion, and good resolution after development. In other words, it must have excellent developability with an appropriate solvent.

D) It is essential that the resist of the present invention can be applied to both sides of a printed circuit board so that both sides can be exposed simultaneously. That is, there must be no so-called show-through, in which UV light exposed from one side transmits through the resist and the base material and cures the resist on the other side. Unless such a problem is solved, the difference in the negative mask pattern used on both sides of the base material appears on the opposite side, which significantly impairs the practicality.

E) The resist of the present invention is obtained by
It is essential that the negative mask can be exposed in close contact with the resist. If this problem is not solved, the resist and the negative mask adhere to each other due to the tackiness of the resist itself and the softening of the resist due to a rise in temperature during exposure. Then, it becomes necessary to clean the negative mask for each exposure, and the practicality is significantly impaired.

F) The resist of the present invention must have good coatability. That is, when a resist is applied to one side of a printed circuit board by screen printing, a roll coater, or the like, it is necessary to have a viscosity property as an appropriate ink so that the thickness is uniform and no void remains. .

G) The resist of the present invention must be such that after one side of the resist is coated, it is pre-dried and the other side is coated with the resist. If the pre-drying is insufficient, the resist cannot be printed on the other surface while the viscous resist is applied on one surface. If pre-drying becomes excessive,
The reaction of the resist proceeds, and a difference occurs in the characteristics of the resist on both sides. In order to avoid such a problem, it is essential to be able to perform predrying appropriately.

H) The resist of the present invention is formed on a printed circuit board as a product, and it is essential that the solder resist has good heat resistance to withstand repeated soldering. That is, even if solder immersion at 260 ° C. for 10 seconds is repeated about 10 times, or by soldering with hot air, infrared rays, solvent vapor, or the like, the resist on the printed circuit board has abnormalities such as blistering and peeling. Is essential. It should be emphasized that such properties are required for resists after a severe chemical copper plating process.

I) The resist of the present invention is formed on a printed circuit board as a product, and it is essential that the resist can maintain high insulation. That is, it is necessary to be able to maintain excellent insulation properties that do not cause insulation deterioration between wirings, especially insulation properties when absorbing moisture. It should be emphasized that such properties are required for resists after a severe chemical copper plating process.

J) The resist of the present invention is formed on a printed circuit board as a product, and it is essential that the resist has excellent chemical resistance. That is, it is necessary that the resist is not dissolved or deteriorated by a soldering flux, a cleaning solvent, or the like used in a mounting process of mounting components on a printed circuit board. It should be emphasized that such properties are required for resists after a severe chemical copper plating process.

K) It is essential that the resist of the present invention has good alkali resistance after being formed on a printed circuit board as a product. That is, since a severe chemical copper plating process is performed, the resist must not be dissolved or deteriorated by a high-temperature, strongly alkaline chemical copper plating solution.

L) It is essential that the resist of the present invention has good plating resistance after being formed on a printed circuit board as a product. Such characteristics are specifically as follows. When manufacturing a printed circuit board by the part-reactive method, it is essential that the resist on the conductor circuit does not peel off in the step of chemical copper plating. The printed circuit board on which the resist is formed is immersed in a harsh chemical copper plating solution of high temperature and strong alkali for a long time, and the deposition potential of chemical copper plating on the copper wiring pattern under the solder resist is -0.6 to-. 0.9V works for a long time. Even after passing through such a severe process, a decrease in adhesion and peeling must not occur at the interface between the copper and the resist.

The mechanism by which the adhesion force is reduced or peeling is not clear, but empirically, if the deposition potential of the chemical copper plating becomes the driving force for the peeling reaction or if copper oxide exists at the interface between copper and the resist. It has been found that peeling proceeds extremely rapidly. From these facts, the oxide at the interface between the circuit copper foil and the resist is electrochemically reduced by the chemical copper plating deposition potential, resulting in the destruction of the bond between the copper and the resist, which causes adhesion, and peeling It is estimated. Accordingly, plating reactivity (peeling resistance) is also a kind of cathodic peeling resistance.

It should be strictly distinguished between the plating resistance and the generally known plating resistance. In general, what is referred to as plating resistance often indicates the above-described alkali resistance, which is completely different from plating resistance (peeling resistance).

The problem of plating reactivity (peeling resistance) is that when a printed circuit board is manufactured by the part-reactive method,
One of the most notable points is that if this problem is not solved, the resist on the circuit copper foil will peel off, losing practicality at all.

M) After forming the resist of the present invention on a printed circuit board as a product, it is essential that no harmful components are eluted or extracted from the resist into the plating solution in the step of chemical copper plating. If such plating elution resistance is unresolved, the components eluted or extracted from the resist adversely affect the deposition reaction of copper plating, and as a result, the plating reaction is stopped or delayed, or the deposited copper is Crystal orientation and physical properties are significantly degraded. Therefore, the connection reliability of the through hole of the printed circuit board, the wettability of the solder, and the connection reliability are reduced, and the practicality is lost at all.

The mechanism by which harmful components adversely affect the deposition reaction of copper plating is extremely complicated because the plating reaction involves a catalytic reaction of the reducing agent on the copper surface. Therefore, it is necessary to ensure plating elution resistance.

The problem of plating elution resistance is one of the most important points to consider when manufacturing printed circuit boards by the part-reactive method. Unless this problem is solved, the manufactured printed circuit boards will not be practically used. Not only that, it also contaminates the chemical copper plating solution, necessitating the disposal of a large amount of plating solution, and the loss is remarkable.

Furthermore, the plating elution resistance and the alkali resistance described above should be strictly distinguished. That is, if the alkali resistance is insufficient, the resist itself dissolves in the alkali, whereas if the plating elution resistance is insufficient, only specific components in the resist elute into the plating solution.

The object of the present invention is to provide the above-mentioned a) to m)
To provide a high-density printed circuit board using a photocurable resist composition that satisfies all of the above problems.

Another object of the present invention is to provide the above a)
An object of the present invention is to provide a method for manufacturing a printed circuit board using a photocurable resist composition that satisfies all of the problems up to m).

[0046]

(Means for Solving the Problems) (Means-1) The above problems-
The first object of the present invention is to provide a printed wiring board comprising: a through-hole having a conductor layer disposed on an inner peripheral surface thereof and a circuit pattern disposed on a substrate surface; This is achieved by a high-density printed wiring board comprising a double layer of a metal plating base layer having a resistance to a copper etchant and a copper plating integrally coated on at least a land portion of the circuit pattern. .

The material of the metal plating underlayer having the copper etchant resistance is determined by the manufacturing process, that is, by the type of etchant used when etching the copper foil on the substrate to form a circuit pattern. . Usually, an alkaline etching solution is used. In such a case, for example, nickel plating which is resistant to alkali is practical and preferable. Further, in the case of an acidic etching solution, for example, tin-lead-based solder plating having acid resistance is preferable,
If it is resistant to both acidic and alkaline solutions, such as gold plating, it can be used in either case.

The practical thickness of the underlayer conductor is preferably at least 0.1 μm, more preferably 0.1 μm.
It is about 5 to 2 μm.

Also, for example, 20 μm or less, practically 1 μm
If it is a very thin copper plating of about 15 μm, it may be present as a base of the metal plating having the copper etching solution resistance. Further, it is desirable that a solder resist is coated on the circuit board except for the inside of the through hole and the land. This solder resist serves as a plating resist mask when forming copper plating on a conductor from at least the land portion to the inside of the through hole, and also serves as an insulating protective film because it covers the surface circuit pattern.

The second object is as follows: (2) a step of forming a through-hole in a copper-clad laminate substrate, a step of forming a conductor layer in the through-hole, and a step of forming a through-hole opening on the substrate. Forming a circuit pattern including a land formed in the through-hole, wherein the first step of forming a conductor layer in the through-hole includes the step of forming a circuit pattern in the through-hole. After forming a metal plating having a copper etching resistant property on the entire surface, the metal plating having a copper etching resistant property formed on the substrate surface is removed by mechanical polishing, and the copper etching resistant solution is provided only in the through holes. Forming a metal plating having a characteristic , and a circuit including the land.
In the step of forming a pattern, a photosensitive resist made of an electrodeposition type UV resist is coated on the entire surface, exposed through a mask on which a predetermined circuit pattern is drawn, and processed to form an etching resist mask pattern. Selectively etching the copper foil on the substrate using the pattern, peeling and removing the resist mask pattern to form a circuit pattern including lands, and in the through hole
The second step of the step of forming a conductor layer is covered with copper plating from the metal plating having the copper etchant resistance formed in the through hole to at least the land of the opening, and the copper resistant layer is formed in the through hole. This is achieved by a method for manufacturing a printed wiring board, which comprises a step of forming a conductor layer composed of a double layer of metal plating having etchant properties and copper plating coated thereon.

Preferably, (3) a step of forming a through-hole in the copper-clad laminate substrate, a step of forming a conductor layer in the through-hole, and a step of forming a through-hole around the through-hole on the substrate And a step of forming a circuit pattern including lands, wherein the first step of forming a conductor layer in the through hole is performed on the entire surface of the substrate including the inside of the through hole. After forming nickel plating as a base layer having resistance to a copper etching solution, the nickel plating formed on the substrate surface is removed by mechanical polishing,
The step of forming nickel plating only in the through hole, the step of forming a circuit pattern including the land ,
A photosensitive resist composed of an electrodeposition type UV resist is coated on the entire surface, exposed through a mask on which a predetermined circuit pattern is drawn, subjected to a phenomenon treatment to form an etching resist mask pattern, and using this resist mask pattern on a substrate. Step of forming a circuit pattern including lands by selectively etching a copper foil and removing and removing a resist mask pattern
And forming a conductor layer in the through hole.
The two steps consist of a double layer of nickel plating and nickel plating in the through hole, and copper plating coated thereon, from the nickel plating formed in the through hole to at least the land of the opening. This is achieved by a method for manufacturing a printed wiring board, which is characterized by comprising a step of forming a conductor layer.

(4) A step of forming a base conductor layer having resistance to an acidic etching solution such as solder plating as a metal plating base layer having a copper etching solution resistance of the above (3), and a through hole is formed on the substrate. This is achieved by a method for manufacturing a high-density printed circuit board in which a circuit pattern is formed using an acidic solution as an etchant for selectively etching a copper foil of a copper-clad laminate including lands formed at the periphery of an opening. .

(5) The step (3) of forming a base conductor layer having resistance to an acidic and alkaline etching solution such as gold plating as a metal plating base layer having resistance to a copper etching solution as described in (3) above. A method for manufacturing a high-density printed circuit board including a step of forming a circuit pattern using an acidic or alkaline etchant as an etchant for selectively etching a copper foil of a copper-clad laminate including lands formed at the periphery of a through-hole opening portion Is achieved by

(6) When copper plating is integrally formed from the inside of the through hole to at least the land, a solder resist is applied on the circuit board excluding the inside of the through hole and the land as a pre-process of copper plating. This is achieved by the method for manufacturing a high-density printed circuit board according to any one of the above (2) to (5), which further comprises a step of coating.

(7) In the step of forming a conductor layer in the through hole, the step of forming a metal plating underlayer having copper etchant resistance is performed on the entire surface of the substrate including the inside of the through hole. The metal plating having a copper etching solution resistance corresponding to the amount formed on the substrate surface is removed by mechanical polishing, and the metal plating is left only in the through-hole, and the step of forming the copper plating is performed. Exposure through a mask on which a predetermined circuit pattern is drawn, and processing by phenomena to form an etching resist mask pattern. Using this resist mask pattern, selectively etch the copper foil on the substrate and peel off the resist mask pattern. After removing to form a circuit pattern including lands,
According to the method of manufacturing a printed circuit board according to the above (2), which is a step of performing copper plating coating from a metal plating base layer having a copper etchant resistance formed in the through hole to at least a land of the opening, (8) In the step of forming a conductor layer in the through-hole, after performing a step of applying a metal-plated conductor layer having copper etchant resistance such as nickel plating to the entire surface of the substrate including the inside of the through-hole, The conductor layer formed on the substrate surface is removed by mechanical polishing, and the step of forming only the inside of the through hole is performed.The step of applying copper plating is performed by coating a photosensitive resist on the entire surface and forming a predetermined circuit pattern. Exposure and phenomena processing are performed through the drawn mask to form an etching resist mask pattern, and the copper foil on the substrate is selectively etched using this resist mask pattern. And forming a circuit pattern including lands by stripping and removing the resist mask pattern, and then performing copper plating covering from the conductor layer such as nickel plating formed in the through hole to at least the land of the opening. This is achieved by the method for manufacturing a printed circuit board according to the above (2).

(9) The method for producing a printed circuit board according to the above (7) or (8), wherein the step of depositing and forming the metal plating having the copper etching solution resistance to a thickness of at least 0.1 μm is performed. Achieved.

(10) The photosensitive resist is preferably an electrodeposition type UV resist, but may be used as a film resist depending on the application.

(11) As a step prior to the step of forming the metal plating base layer having the resistance to the copper etching solution, 20
It is also possible to add a step of depositing a chemical copper plating or a copper plating having a thickness of 1 μm or less, preferably 1 to 15 μm.

(Means 2) In order to solve the above-mentioned problem-2, a metal (for example, nickel, palladium or the like) which is hardly electrolytically eroded and has good adhesion to a solder resist is coated on a copper pattern. Is desirable.

(Means-3) In order to achieve the object of the above-mentioned task-3, the present invention provides a photosensitive solder resist composition having plating resistance, comprising: a polyfunctional unsaturated compound which is solid at room temperature; A liquid polyfunctional unsaturated compound, a photopolymerization initiator, an epoxy resin, and a curing agent for the epoxy resin,
A photocurable resist composition comprising melamine or a derivative thereof, an antifoaming agent, a pigment, and an organic solvent is used.

The polyfunctional unsaturated compound which is solid at room temperature used in the present invention is, for example, a compound having a large number of unsaturated groups in a molecule such as a diallyl phthalate resin. By using such a resist, it is possible to obtain a resist that satisfies the above-mentioned many problems at the same time.

Specifically, the diallyl phthalate resin is
It comprises a prepolymer of diallyl ester of ortho, iso or terephthalic acid. Such a prepolymer is also referred to as a β-polymer. For example, Naoki Yoshimi, “Diallyl phthalate resin”, published by Nikkan Kogyosha (Showa 44)
Year) describes its detailed manufacturing method and properties. Commercial products can also be obtained from Daiso KK. A preferred prepolymer for use in the present invention has a molecular weight of about 3,000 to 30,000, and a molecular weight of 3,000 or less results in poor adhesion exposure to a negative mask, and a molecular weight of 3,000 or less.
If the value is 0 or more, the developing property is impaired. Also, when a prepolymer is used, it does not prevent a small amount of the diallyl phthalate monomer or the γ-polymer having a three-dimensional network structure remaining or produced in the synthesis of the prepolymer.

Further, the photosensitive solder resist composition having plating resistance according to the present invention comprises a polyfunctional unsaturated compound which is liquid at room temperature and has at least two or more ethylene bonds in a molecule. . Such a compound is obtained, for example, by an esterification reaction between an unsaturated carboxylic acid and a dihydroxy or higher polyhydroxy compound. As unsaturated carboxylic acids, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, etc., on the other hand, as dihydroxy or higher polyhydroxy compounds, ethylene glycol, diethylene glycol, trimethylolpropane,
Pentaerythritol, dipentaerythritol and derivatives thereof can be mentioned.

Compounds obtained by the esterification reaction between the unsaturated carboxylic acid and the polyhydroxy compound include diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, 1.5 pentanediol diacrylate, and 1.6 hexanediol. Diacrylate, dimethacrylate, triacrylate compounds represented by diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, diethylene glycol dimethacrylate, 1.3 butanediol dimethacrylate and the like, and tri, tetra, penta, hexaacrylate of dipentaerythritol Or methacrylate, sorbitol tri, tetra, penta, hexaacrylate or methacrylate Polyfunctional acrylates typified over preparative, methacrylate compounds and, oligoester acrylates, oligoester methacrylate,
Can be mentioned.

A compound formed by addition reaction of a divalent or higher valent epoxy resin with an unsaturated carboxylic acid can be used as a polyfunctional unsaturated compound which is liquid at room temperature. Examples of such compounds include polyfunctional unsaturated compounds which are liquid at room temperature and are formed by an addition reaction of bisphenol A type or novolak type epoxy resin with acrylic acid or methacrylic acid.

The number of functional groups contained in the molecule of the polyfunctional unsaturated compound is preferably as large as possible, more preferably at least 2 or more, preferably 3 or more, more preferably 6 or more.

The above examples do not limit the addition of a monofunctional unsaturated compound, and a mixture with a polyfunctional unsaturated compound can be used if necessary.

Furthermore, the photosensitive solder resist composition having plating resistance according to the present invention comprises a photopolymerization initiator. Examples of photopolymerization initiators, acetophenone,
Benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzoin alkyl ketal, thioxanthone, thioxanthone, anthraquinone, anthraquinone and derivatives or analogs thereof,
Examples thereof include 1-hydroxycyclohexyl phenyl ketone, derivatives or analogs thereof, and α-amino ketone compounds represented by 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-propene-1. If necessary, a mixture of photopolymerization initiators can be used. If necessary, an amine compound or the like which sensitizes the action of the photopolymerization initiator can be used.

Further, the photosensitive solder resist composition having plating resistance according to the present invention comprises an epoxy resin. As the epoxy resin, those having an average of two or more epoxy groups per molecule, for example, a polyhydric phenol such as bisphenol A, halogenated bisphenol A, catechol, resorcinol or a polyhydric alcohol such as glycerin. Polyglycidyl ether or polyglycidyl ester obtained by reacting epichlorohydrin with a basic catalyst, an epoxy novolak obtained by condensing epichlorohydrin with a novolak-type phenol resin, an epoxidized polyolefin epoxidized by a peroxide method, Epoxidized polybutadiene, dicyclopentadiene oxide, or epoxidized vegetable oil may, for example, be mentioned.

Furthermore, the photosensitive solder resist composition having plating resistance according to the present invention comprises a curing agent for epoxy resin. As a curing agent for epoxy resin,
Amine compounds and imidazoles are preferred. Examples of amine-based compounds include, for example, aliphatic compounds such as ethylenediamine, hexamethylenediamine, and triethylenetetramine, and aromatic compounds such as diphenylamine, 4,4′-diaminodiphenylmethane, and phenylenediamine. There are also imidazoles, alkyl imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole and 2-phenylimidazole, and derivatives of imidazole include purine, 2,6-diaminopurine, Representative examples include 2-aminobenzimidazole and the like, and 2,4-diamino-6 {2′- obtained by the addition reaction of 2,4-diamino-6-vinyl-s-triazine with alkylimidazole. Methyl imidazole
(1 ′)} Ethyl-s-triazine, 2,4-diamino-6 {2′-ethyl
-4'-methylimidazole- (1 ')} ethyl-s-triazine,
2,4-diamino-6 {2'-undecylimidazole- (1 ')} ethyl-s-triazine, 2,4-diamino-6 {2'-phenylimidazole- (1')} ethyl-s-triazine Alternatively, 2,4-diamino-6 {2′-methylimidazole- (1 ′)} ethyl-s-triazine / isocyanuric acid adduct and the like can be mentioned. Examples of other amine-based curing agents include boron trifluoride monoethylamine. If necessary, a mixture of amine-based curing agents can be used. In particular, 2-vinyl-
Compounds obtained by the addition reaction of 4,6-diamino-s-triazine with alkylimidazole are preferred.

Further, the photosensitive solder resist composition having plating resistance according to the present invention comprises melamine or a derivative thereof. Representative examples of melamine or a derivative thereof include melamine, 2,4-diamino-6-methyl-s-triazine, and 2,4-diamino-6-phenyl-s-triazine, and 2,4 -Diamino-6-vinyl-s-
2,4-diamino-6 {2'-methylimidazole- (1 ')} ethyl-s-triazine, 2,4-diamino-6 {2'-ethyl-4 obtained by addition reaction of triazine and alkylimidazole '-Methylimidazole- (1')} ethyl-s-triazine, 2,4-diamino-6 {2'-undecylimidazole- (1 ')} ethyl-s-triazine, 2,4-diamino-6 { 2'-phenylimidazole-
(1 ')} Ethyl-s-triazine or 2,4-diamino-6 {2'-
Methylimidazole- (1 ′)} ethyl-s-triazine / isocyanuric acid adducts and the like are also mentioned as melamine derivatives.

Preferred as such a melamine derivative is one having a diaminotriazine skeleton in the molecule, more preferably having a solubility in water of about 1 wt% or less, more preferably about 0.1 wt% or less. Yes, more preferably about 0.01 wt.
% Or less.

Furthermore, the photosensitive solder resist composition having plating resistance according to the present invention comprises an antifoaming agent. As such an antifoaming agent, an organic silicon compound containing a siloxane bond typified by silicone oil is mainly used.

Further, the photosensitive solder resist composition having plating resistance of the present invention contains a pigment. As such pigments, phthalocyanine, phthalocyanine green, phthalocyanine blue, and the like, which are pigments having a phthalocyanine skeleton excellent in heat resistance, are mainly used.

Furthermore, the photosensitive solder resist composition having plating resistance according to the present invention comprises an organic solvent. As such organic solvents, methyl, ethyl, butyl cellosolve, acetates thereof, and the like, methyl, ethyl, butyl carbitol, and high-boiling solvents such as terpineol are mainly used.

Further, the photosensitive solder resist composition having plating resistance according to the present invention can be further improved in performance by adding other additives as necessary. Such additives include a thixotropic agent for adjusting the viscosity of the resist, a filler for adjusting the heat resistance of the resist, an ultraviolet absorber for adjusting the resolution of the resist, and the storage stability of the resist. And the like.

One example of such a thixotropic agent is ultrafine quartz powder, one example of such a filler is fine quartz powder, and one example of such an ultraviolet absorber is 4-t-butyl-4′-. Methoxy-
Dibenzoylmethane, 2-ethylhexyl-p-methoxycinnamate, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t
ert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- {2' -Hydroxy
-3- (3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl} benzotriazole and the like.
An example of such a polymerization inhibitor is hydroquinone or a derivative thereof.

The preferred compounding ratio for constituting the composition of the present invention is that the polyfunctional unsaturated compound which is solid at room temperature is 100 parts by mass.
The polyfunctional unsaturated compound which is liquid at room temperature is 5 to 30 parts by weight, preferably 10 to 30 parts by weight, more preferably 10 to 20 parts by weight, and the photopolymerization initiator is 2 to 12 parts by weight. Parts by weight, 5 to 4 parts of epoxy resin
0 parts by weight, and 0.1 to 5
Parts by weight, and 1 to 2 melamine or a derivative thereof
0 parts by weight, preferably 2 to 15 parts by weight, more preferably 4 to 10 parts by weight.
Parts by weight, the pigment is 0.2 to 10 parts by weight, and the organic solvent is 50 to 100 parts by weight. If necessary, one type of compound may be used as the epoxy resin curing agent and the melamine derivative.

The upper and lower limits of the mixing ratio are selected from the results of careful selection so that the above-mentioned objects (a) to (m) of the present invention can all be satisfied simultaneously.

Next, means for manufacturing a high-density printed circuit board using the above-mentioned photosensitive solder resist composition having plating resistance, which is the second object of the present invention, will be described with reference to FIG.

The copper-clad laminate 1 is obtained by a method well known to those skilled in the art.
(1 in FIG. 21), a catalyst for chemical copper plating is applied to the entire surface of the substrate including the inside of the through hole (FIG. 2).
1, 2)).

Next, a predetermined portion is etched by a method well known to those skilled in the art to form conductor circuits 9 on both surfaces of the substrate (FIGS. 21 and 3).

Next, the photosensitive solder resist composition having plating resistance of the present invention is applied to one surface of a substrate including a conductive circuit, and the substrate coated with the resist is dried to solidify the resist. This method is repeatedly performed on the back surface, or a photosensitive resist composition having plating resistance is simultaneously applied to both surfaces of the substrate and then dried to form a solidified resist layer on both surfaces of the substrate. The drying temperature is preferably 60 to 100 ° C., and the drying time is preferably 0.2 to 2 hours.

Next, a negative mask is brought into close contact with the solidified resist layers on both sides of the substrate, and 0.1 to 1
Exposure is performed by irradiating UV light of J / cm ² . Next, the negative mask is removed from the resist surface, and the unexposed portions are dissolved and removed by development. Solvents suitable for such development include:
A nonflammable chlorine-based solvent such as 1,1-trichloroethane is used, and a development time of 0.5 to 5 minutes is selected.

Next, the substrate is heated to cure the resist portion on which the pattern has been formed. Curing conditions are 120 to 18
0 ° C., 0.2 to 2 hours are selected.

Preferably, the resist cured by heating is again irradiated with UV light to accelerate the curing of the resist. The exposure amount suitable for such post-exposure is 1 to 10 J / cm ² .

Through the above steps, a resist layer 6 is formed on the substrate.
Are formed (FIGS. 21 and 4).

Next, the substrate is immersed in a chemical copper plating solution, and a thick chemical copper plating 7 is applied only to the main portion including the through holes and lands, thereby producing a high-density printed circuit board. FIG. 21 and 5)). The thickness of the copper plating is usually selected to be 10 to 40 μm. It is a significant and important advantage of the present invention that no such delamination of the resist on the circuit copper foil occurs during such chemical copper plating.

In the production of a high-density printed circuit board as described above, the resist of the present invention can simultaneously satisfy all of the above-mentioned problems (a) to (m) of the present invention. For this reason, it has become possible to manufacture an unprecedented high-density printed circuit board.

[0090]

When the copper foil on the substrate is selectively etched to form a circuit pattern, the reliability of the through-hole is maintained by a metal plating base layer having a copper etching solution resistance such as nickel plating formed in advance. The surface circuit pattern allows the use of an electrodeposition type resist, enables formation of a fine line pattern with high resolution, and is effective for forming a high-density circuit board having small-diameter through holes. For example, the reason will be described in detail with reference to FIG. 7, but in comparison with FIG. 6 described above as a problem of the prior art, the operational characteristics of the present invention can be more easily understood.

FIG. 7 shows a process diagram of the printed circuit board. Since FIG. 7 is a schematic diagram prepared for explaining the problem in the through hole, only the main processes are shown. The steps are considerably omitted.

First, in the step (a), the nickel plating 4 is previously coated in the through hole 2 of the copper clad laminate, and in the step (b), the electrodeposition resist 5 is coated on the entire surface of the substrate including the inside of the through hole 2. In step (c), a resist mask pattern 8 is formed through exposure and development using a mask (not shown) on which a circuit pattern is drawn. At this time, even if a resist defect 8a due to exposure unevenness occurs in the small-diameter through hole 2, in the present invention, the resist defect 8a does not have any adverse effect as will be understood in the next step. That is, in the step (d), the exposed copper foil on the substrate surface is selectively etched using the resist mask pattern 8 obtained in the step (c) to form a circuit pattern. Even if there is a resist defect 8a in the inside, since the nickel plating 4 has etching resistance to the etching solution for the copper foil, the reliability in the through hole 2 is not impaired, and the high resolution fine line pattern is not lost. Can be formed.

After the step (d), a step of applying a solder resist on the entire surface except for the through hole and the land portion 9a and a process from the through hole to the land portion 9a by utilizing the mask function of the solder resist. The step of selectively and integrally forming the copper plating is omitted, but these will be specifically described in the following Examples.

In the present invention, the nickel plating 4 covering the inside of the through-hole 2 is excellent in providing a catalyst when using a chemical copper plating process, and acts as a base conductor layer when performing electrolytic plating. Further, since the adhesiveness with the copper plating film is good, blisters in the holes are hardly generated, and the peel strength is improved.

Further, in the step (a) of FIG. 7, the nickel plating 4 is previously coated in the through hole 2 of the copper clad laminate, but in the process leading to this step, the entire surface of the substrate including the inside of the through hole 2 is covered. The nickel plating 4 is formed, and the nickel plating 4 formed on the surface of the substrate is removed by means of polishing or the like, and is left only in the through hole. It is also possible to form the nickel plating 4 only in the through hole 2 by using lithography and plating technology instead of the polishing means. In any case, nickel plating is not formed on the substrate surface, or it is necessary to remove nickel plating even if it is formed, for the following reasons. In other words, if a conductor layer that is resistant to an etching solution of copper foil such as nickel plating is formed on the copper foil on the substrate surface, this conductor layer hinders the formation of a circuit pattern by etching the copper foil. Accordingly, an etching step for forming a circuit pattern is required for nickel plating as a previous step. As a matter of course, this nickel plating is resistant to the etching solution for the copper foil, so that a different etching solution must be used, which increases the number of steps, which is not preferable.

In the case where the copper pattern surface is coated with nickel, the stability of copper and nickel is reduced by P in FIG.
Comparing with the H-potential state diagram, it can be seen that nickel has a wider passivation and non-transformation region and is less ionizable than copper. In addition, palladium, gold, and the like are also less susceptible to electrolytic corrosion than copper for the same reason. In addition, since nickel has a wide oxidized passive state (NiO, NiO _2, etc.) region, a solder resist containing a large amount of hydrogen functional groups (—H, —OH)
It has a strong hydrogen bond with oxygen in the nickel layer.
(FIG. 17) By coating the copper foil pattern surface with nickel, the electrolytic corrosion of copper is suppressed and the adhesion to the solder resist is also improved.

[0097]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows the structure of a printed circuit board according to the present invention. Multi-layer copper-clad laminate 1 with inner layer circuit
In the through hole 2a, a nickel plating 4 having a thickness of 1 μm is formed as a base, and the surface thereof is coated with a copper plating 7 to form a double structure. Copper plating 7 is formed in the through hole 2a embedded in the inner layer, and the surface thereof is coated with nickel plating 4 to form a double structure. The copper plating 7 formed integrally with the copper plating 7 in the through holes 2 and 2 covers the land portion 9a of the substrate surface and the copper foil circuit pattern 9 in the inner layer. 1 μm nickel plating is coated. Further, the entire surface of the substrate including the through hole 2 and the surface circuit pattern 9 excluding the lands is covered with a solder resist 6.

FIGS. 2, 3 and 4 are process diagrams for explaining an example of the method for manufacturing a high-density printed circuit board according to the present invention, and the contents will be sequentially described in accordance with the following steps (a) to (p). I do.

Step (a) A through hole 2 is formed at a predetermined position of a double-sided copper-clad laminate 1 serving as an inner layer core by drilling or the like.
Drill a.

Step (b) After applying a tin / palladium catalyst to the inside of the through-hole 2a and the copper foil surface according to a standard method, copper 7 having a predetermined thickness is deposited on the entire surface by electrolytic copper plating or chemical copper plating.

Step (c) After the copper surface is roughened, copper is activated with a palladium chloride solution, and nickel 4 is plated with 0.5 to 5 μm on the entire surface including the through holes 2a.

Step (d) The nickel layer on the surface is mechanically polished and removed by a belt sander.

Step (e) After roughening the exposed surface copper plating, an electrodeposition resist 5 (Eagle 200 manufactured by Shipley Co., Ltd.) is used.
0) is coated on the entire substrate including the through-hole 2a under the conditions of a voltage of 80 V and a conduction time of 15 seconds, and a circuit negative mask is positioned at a predetermined position and exposed at a light exposure of 200 mJ / cm ² . Then, a developer (XP-6 manufactured by Shipley Co., Ltd.)
In 504), the unexposed portion of the resist is developed and removed.
A circuit is formed by the electrodeposition resist 5. This electrodeposited resist 5 becomes an etching resist in the next step.

Step (f) After the copper exposed on the surface is dissolved and removed with an alkaline etching liquid (Apro bath solution manufactured by Meltex Co., Ltd.), the electrodeposited resist is removed by a stripping liquid (X-ray manufactured by Shipley Co., Ltd.).
(P-6504), the copper foil circuit 9 is formed independently. At this time, since the inside of the through hole 2a is protected by nickel, the inner layer copper foil is not melted.

Step (g) After the surface of the substrate copper foil is roughened, copper is activated with a palladium chloride solution, and nickel 4 is plated on the entire surface including the through holes 2a by 0.5 to 5 μm.

Step (h) An outer copper foil and a predetermined number of prepregs are laminated in a predetermined order on the inner core 1 on which the predetermined circuit 9, the through hole 2a and the land 9a are formed by the above (a) to (g). Then, hot pressing is performed according to a standard method to form a multilayer copper-clad laminate 1a.

Step (i) A through-hole 2 is formed in a predetermined position of the multilayer copper-clad laminate 1a by drilling or the like.

Step (j) After applying a tin / palladium catalyst to the inside of the through-hole 2 and the surface of the copper foil according to a standard method, nickel 4 is applied to the entire surface of the substrate including the through-hole 2 by 0.5 to 5 μm.
Plate about m.

Step (k) The nickel layer 5 on the substrate surface is mechanically polished and removed by a belt sander or the like.

Step (l) After roughening the exposed surface copper plating, an electrodeposition resist 5 (Eagle 200 manufactured by Shipley Co., Ltd.) was used.
0) is coated on the entire substrate including the through-hole 2a under the conditions of a voltage of 80 V and a conduction time of 15 seconds, and a circuit negative mask is positioned at a predetermined position and exposed at a light exposure of 200 mJ / cm ² . Then, a developer (XP-6 manufactured by Shipley Co., Ltd.)
In 504), the unexposed portion of the resist is developed and removed.
A circuit is formed by the electrodeposition resist 5. This electrodeposited resist 5 becomes an etching resist in the next step.

Step (m) After the copper exposed on the surface is dissolved and removed with an alkali etching solution (Apro bath solution manufactured by Meltex Co., Ltd.), the electrodeposited resist is removed by a stripping solution (X, manufactured by Shipley Co., Ltd.).
(P-6504), the copper foil circuit 9 is formed independently. At this time, since the inside of the through hole 2 is protected by nickel, the inner layer copper foil is not melted.

Step (n) After roughening the surface of the substrate copper foil, activate copper with a palladium chloride solution to deposit nickel 4 on the through-hole 2 and the surface circuit pattern 9 in a thickness of 0.5 to 5 μm.
Plating.

Step (o) Plating-resistant solder resist 6
Is applied on both sides by a screen printing method, a spray coater method, or the like, and then a resist-positive mask is positioned at a predetermined position and exposed under the conditions of an exposure amount of 200 to 1000 mJ. Thereafter, the unexposed portion of the resist is developed and removed with a developing solution (111-trichloroethane), and a solder resist 9 is formed on the entire surface of the substrate except for the through-holes 2, the through-hole lands 9a and the imposed component lands 16.

Step (p) After activating the exposed nickel 4 with a palladium chloride solution, a predetermined thickness of chemical copper plating 4 is printed on the through-hole 2, the through-hole land 9a and the imposition land to print. The substrate is completed.

(Embodiment 2) The steps (c) and (d) in the embodiment 1 can be omitted, and the structure of the completed printed circuit board is not changed.

(Embodiment 3) The step (g) in the embodiment 1 can be omitted, and the structure of the completed printed circuit board is shown in FIG.

(Embodiment 4) In the embodiment 1, the step (n) can be omitted.
Becomes

(Embodiment 5) Although the electrodeposition type UV resist 5 was used as the photoresist in the steps (e) and (l) in this example, the photoresist is not limited to the electrodeposition type UV resist and may be used depending on the application. Film-type photosensitive resists commonly used in the manufacture of printed circuit boards, UV resists that use light as an exposure source, and electron beam resists that use an electron beam as an exposure source, which are used in the semiconductor industry, etc., can be used. Needless to say,

(Embodiment 6) By combining the above Embodiments 2 to 5, several other types of printed circuit board structures are possible. For example, a combination of the third embodiment and the fourth embodiment results in a printed circuit board structure shown in FIG.

(Embodiment 7) As the copper plating process, chemical copper plating is practical and desirable, but electrolytic plating can also be used.

(Embodiment 8) The formation of the surface circuit pattern 9 by the copper foil etching in the above steps (f) and (m) is performed in this embodiment by using ferric chloride, cupric chloride and an alkali etching solution. However, the etching can be performed in the same manner using other well-known etching liquids. That is, instead of the alkaline etching solution of this embodiment, for example, an iron-based acidic etching solution such as ferric chloride may be used. However, in this case, the nickel plating 4 serving as the conductor layer in the through hole 2 has no resistance to the acidic etching solution and dissolves. Therefore, the plating is replaced with another plating that does not dissolve, for example, a solder plating such as Pb-Sn. There is a need.

(Example 9) In place of the nickel plating 4, if a conductor layer resistant to acid and alkali such as gold (Au) plating is used, it is affected by the copper foil etching solution. Never. Both such solder plating and gold plating can be easily formed by well-known chemical plating or electrolytic plating similarly to nickel plating.

(Embodiment 10) In these embodiments, the underlying conductor layer 4 such as nickel plating in the through hole 2 was directly formed in the hole of the substrate. However, after drilling the through hole, a thin copper plating of 20 μm or less was previously formed. May be formed, and according to this, the plating process at the time of forming the conductor layer 4 such as nickel plating may be more easily performed. That is, in the formation of the conductor layer 4, since this thin copper plating is present on the base, the catalyst applying step can be omitted in the case of chemical plating.
Electroplating is also possible. However, this thin copper plating requires a thickness restriction, and if it exceeds 20 μm, the conventional swelling problem occurs and the effect is adversely affected, which is not preferable. Therefore, as described above, it is desirable that the conductor has a minimum thickness of 20 μm or less, more preferably 1 to 15 μm as thin as possible.

Further, the production of a high-density printed circuit board using the photosensitive solder resist composition having plating resistance of the present invention will be specifically described. The photosensitive solder resist composition used in each of the following examples was commonly manufactured by the following method.

The diallyl phthalate resin as a polyfunctional unsaturated compound which is solid at room temperature and used in the present invention is weighed, placed in a separable flask, and the weighed organic solvent is added thereto. And dissolve with stirring for 30 minutes to 2 hours. After the melt is cooled to room temperature, the remaining resist material is added, and the mixture is sufficiently stirred and mixed. Next, kneading is performed two to four times using a three-roll mill to prepare a resist ink for screen printing.

On the other hand, the production of printed circuit boards was commonly performed according to the following method.

After drilling holes 2 at predetermined positions on a glass epoxy double-sided copper-clad laminate 1 (FIGS. 21 and 1) having a copper foil of 1.6 mm thickness and 35 μm, a catalyst for chemical copper plating was passed through a through hole. (See FIG. 2).
1, 2)).

Next, a predetermined portion was etched by a tenting method using a dry film resist for etching to form conductor circuits 9 on both surfaces of the substrate (FIG. 2).
1, 3)).

Next, the photosensitive solder resist ink prepared as described above was applied to one surface of a substrate including a conductive circuit by a screen printing method, and the substrate coated with the resist was dried to solidify the resist. This method was repeated on the back surface to form a solidified resist layer on both surfaces of the substrate. The drying temperature is 80 ° C. and the drying time is 1 hour.

Next, a negative mask was brought into close contact with the solidified resist layer on both sides of the substrate, and 0.5 J / c
Exposure was performed by irradiating m ² UV light. Next, the negative mask is peeled from the resist surface, and the unexposed portions are dissolved by development,
Removed. 1,1,1-trichloroethane was used as a developing solvent, and 1 minute was selected as a developing time.

Next, the substrate was heated to cure the resist portion on which the pattern was formed. The curing condition is 150 ° C. for one hour.

Further, the heat-cured resist is again
Irradiation with UV light of ³ J / cm ² accelerated the curing of the resist.

Through the above steps, a resist layer 6 is formed on the substrate.
Was formed (FIGS. 21 and 4).

Next, the substrate was immersed in a chemical copper plating solution,
A thick chemical copper plating 7 was applied only to the main portion including the through hole and the land (FIGS. 21 and 5). The chemical copper plating solution having the following composition was used. The plating conditions were a bath temperature of 70 ° C., a bath pH of 12.5, and a plating time of 15 hours. During this time, the plating solution components were automatically replenished so that the plating solution composition and the plating conditions were always constant. .
The deposition potential was about -0.7 V (see saturated calomel electrode), and the plating thickness was about 30 µm.

Composition of chemical copper plating solution CuSO ₄ .5H ₂ O 12 g EDTA 2Na 42 g 37% formalin 3 ml NaOH …………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………. The printed circuit board productivity and circuit board characteristics using a photosensitive solder resist composition having plating resistance were commonly determined according to the following items and evaluation methods.

(1) Coating property: A coating film having no voids, air bubbles, etc. remaining in the coating film after screen printing and having a smooth surface was evaluated as good.

(2) Adhesion exposure property: After exposing the negative mask to the resist surface and exposing it with UV light, when the negative mask was peeled off, the resist that did not adhere to the negative mask was evaluated as good.

(3) Developability: When 1,1,1, -trichloroethane is spray-developed at room temperature for 1 minute, the unexposed portion is completely dissolved, and the resist in the exposed portion has no swelling or the like. Was regarded as good.

(4) Show-through resistance: A resist having a thickness of about 40 μm was applied to both sides of a glass epoxy laminate having a thickness of 1.6 mm, dried, and then exposed to a UV of 0.5 J / cm ² from one side. Exposure is performed by irradiating light. In the observation after development, a resist which did not cure the resist on the back surface and could be completely dissolved was evaluated as good.

(5) Alkali resistance: Observed after chemical copper plating, a resist whose resist surface was not dissolved, discolored or roughened was evaluated as good.

(6) Plating resistance: Observation after chemical copper plating showed that the resist applied on the conductor circuit connected to the copper plating deposition portion was free from peeling or discoloration.

(7) Elution resistance to plating: 1 dm ² per liter
A chemical copper plating solution contacting with the resist and having a thickness of about 30 μm and having no abnormality in the crystal orientation of the deposited copper was evaluated as good.

(8) Heat resistance: Solder flux is applied to a printed circuit board after chemical copper plating, immersed in a solder bath at 260 ° C. for 10 seconds, and air-cooled to room temperature. Observation after repeating this operation 10 times,
A sample having no abnormality such as peeling was regarded as good.

(9) Insulation: A resist is applied on a comb pattern conforming to JIS-C-2519 formed on a glass epoxy copper clad laminate, and the insulation resistance when absorbing moisture after chemical copper plating is 10 ⁹ Ω or more. Is good.

Example 11 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 1, and the characteristics 1) to 9) were determined. Table 2 shows the results.

[0146]

[Table 1]

[0147]

[Table 2]

As the polyfunctional unsaturated compound which is solid at room temperature in the present invention, a diallyl phthalate resin (Daiso Dap A:
Daiso K. K. Manufactured, average molecular weight 10,000)
Pentaerythritol tetraacrylate was used as a polyfunctional unsaturated compound which was liquid at room temperature. As the photopolymerization initiator, a mixture of benzophenone and 4,4′-bis (N, N′-dimethylamino) benzophenone was used. Bisphenol A type Epicoat 828 (manufactured by Yuka Shell Epoxy KK) was used as the epoxy resin, and 2-phenylimidazole was used as a curing agent for the epoxy resin. The compounds shown in Table 2 were added as melamine or its derivatives. Silicone oil SH-203 (manufactured by Toray Silicone KK) was used as an antifoaming agent, and phthalocyanine green was used as a pigment. A mixture of ethyl cellosolve acetate and butyl cellosolve acetate was used as the organic solvent.

As a result of manufacturing a printed circuit board using such a resist, to satisfy all the characteristics, the structure of 2,4-diamino-s-triazine, which is common to melamine as melamine of the present invention or its derivative, is required. It was found that a compound having in the molecule may be used. It was also found that the addition amount is suitably 1 to 20 parts by weight based on 100 parts by weight of the solid polyfunctional unsaturated compound at room temperature. If the amount is less than 1 part by weight, the adhesion between the resist and the conductor circuit is insufficient, and the plating resistance is not sufficient. If the amount exceeds 20 parts by weight, excess melamine is slightly dissolved and precipitated in the chemical copper plating solution. It was found that the crystal orientation of copper was abnormal.

Regarding the crystal orientation of copper, normal or abnormal was determined according to the following criteria. As a result of X-ray diffraction, a normal copper plating film in which the orientation of the (111) plane is prioritized as shown in FIG.
As shown in (1), the (200) plane is preferentially oriented. Such abnormalities may not appear remarkably in the mechanical properties such as the tensile strength and elongation of the plating film.However, when soldering and mounting the printed circuit board, it causes cracks in the copper plating through holes. This is an anomaly that should not exist from the viewpoint of through hole reliability.

Further, from the results in Table 2, it was also found that the melamine derivative having no 2,4-diamino-s-triazine skeleton in the structure had insufficient plating resistance.

(Example 12) The photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 3, and the characteristics 1) to 9) were determined. Table 4 shows the results.

[0153]

[Table 3]

[0154]

[Table 4]

In this example, 3 parts by weight of melamine was used in order to secure the plating resistance of the resist, and the effect of the epoxy resin curing agent was determined as shown in Table 4. As is clear from Table 4, the appropriate range for 2-phenylimidazole is 0.1.
It was 1 to 5 parts by weight. When the curing agent is insufficient, the alkali resistance in the chemical copper plating solution becomes insufficient due to the insufficient effect of the resist, and when the curing agent is excessive, the curing reaction proceeds during drying of the resist, and during the development, The unexposed portions were not completely dissolved.

It was also found that if the amount of the curing agent was appropriate, almost the same characteristics could be obtained regardless of the type of the curing agent.

Example 13 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 5, and the characteristics 1) to 9) were determined. Table 6 shows the results.

[0158]

[Table 5]

[0159]

[Table 6]

In this example, in order to ensure the plating resistance of the resist, both the 2,4-diamino-s-triazine ring and the imidazole ring acting as a curing agent for the epoxy resin are contained in the molecule. The effect when 4-diamino-s-triazine-modified imidazole was used was determined. Such compounds are generally synthesized by the addition reaction of 2,4-diamino-6-vinyl-s-triazine and imidazole with active hydrogen. K. More marketed.

A photosensitive solder resist was prepared using a series of 2,4-diamino-s-triazine-modified imidazoles, and the effect was determined. As a result, as shown in Table 6, the effect was obtained in the range of 1 to 20 parts by weight. It was found to have. It was also found that if less than 1 part by weight, the plating resistance was insufficient, and if more than 20 parts by weight, the developability was deteriorated.

In order to secure plating resistance, 2,4-diamino acid sufficient to cure the epoxy resin is used.
Insufficient amount of -s-triazine-modified imidazole added, large amount of 2,4-diamino beyond curing epoxy resin
It was also found that -s-triazine-modified imidazole was required.

Further, in the composition shown in Table 5, 2,4-diamino
The relationship between the contact area with the plating solution and the crystal orientation of the plating film was determined using a resist in which the amount of added -s-triazine-modified imidazole was changed. FIG. 25 shows the result.

The load area contacting the resist is 1 dm ² /
In the case of 1, no abnormal precipitation occurs even at 20 parts by weight, but when the resist area is ² dm ² / l, 15 parts by weight or less is normal, and when it exceeds ² dm ² / l, a little abnormal (shown as middle in the figure). Copper plating was deposited. 10 at 4 dm ² / l
It was found that parts by weight or less were normal. Thus, the fact that the upper limit of the addition amount is affected by the resist loading area indicates that although the elution of the additional component is very small, it cannot be ignored, and the upper limit of the addition amount is determined only experimentally. I knew it would be done.

On the other hand, the lower limit of the amount of addition is limited by the relationship between the range of the curing temperature and time and the plating resistance, and 2 parts by weight is more preferable than 1 part by weight for obtaining the curing temperature and the time at which good plating resistance is obtained. It was also found that the range was wider at 4 parts by weight. Such characteristics are characteristics relating to the yield when mass-producing the printed circuit boards, and the wider the range of the curing temperature and time, the more stable the yield and the more preferable the mass production of the printed circuit boards.

From the above results, the addition amount of 2,4-diamino-s-triazine-modified imidazole is effective in the range of 1 to 20 parts by weight, more preferably in the range of 2 to 15 parts by weight, and still more preferably. It was also found to be in the range of 4 to 10 parts by weight.

Example 14 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 7, and the effect of the melamine derivative was further evaluated in relation to the resist load in contact with the plating solution. I examined it in detail.

[0168]

[Table 7]

The results are shown in FIG. 25. When melamine was used as the melamine derivative, the resist load was 2 d.
At m ² / l or more, the crystal orientation of copper is slightly abnormal and normal copper is not deposited, whereas 2,4-diamino-6 {2′-methylimidazole- (1 ′)} ethyl-s When -triazine was used, an abnormality occurred in the crystal orientation of copper when the resist load was 3 dm ² / l or more. In contrast, 2,4-diamino-6 {2'-
When undecyl imidazole- (1 ′)} ethyl-s-triazine was used, no abnormality occurred in the crystal orientation of copper even at a resist load of 4 dm ² / l. For comparison, a conventional resist to which dicyandiamide was added was 1 dm
^{Even at 2} / l, abnormalities occurred in the crystal orientation of copper.

From these results, even when a melamine derivative is used, as the molecular weight is higher and the solubility in water is lower, abnormal copper is less likely to be deposited even when plating is performed with a larger resist load. Was found to be preferable for mass production of

Conversely, it was also found that the more easily dissolved in water, the greater the tendency to diffuse in the resist and elute into the plating solution. From this viewpoint, the solubility of the melamine derivative in water is required to be about 1 wt% or less, which is almost the same as that of melamine, and more preferably 2,4-diamino-6 {2′-methylimidazole- (1 ′)} ethyl-s. -Approximately 0.1w of triazine
t% or less, and more preferably 2,4-diamino-6 {2′-
It was also found that the content was about 0.01 wt% or less, which is almost the same as that of undecyl imidazole- (1 ′)} ethyl-s-triazine. In the present invention, dicyandiamide is not used because the solubility of dicyandiamide in water is several wt% or more, so that it is easily eluted into the plating solution.

Example 15 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 8, and the characteristics 1) to 9) were determined. Table 9 shows the results.

[0173]

[Table 8]

[0174]

[Table 9]

In this example, the effects of a polyfunctional unsaturated compound which was solid at room temperature and a polyfunctional unsaturated compound which was liquid at room temperature were determined.

As shown in Table 9, as a polyfunctional unsaturated compound which is solid at room temperature, Daiso Dap A (molecular weight: 100
00), Dap L (molecular weight 3500) and Isodap (molecular weight 8000) showed no significant difference.
It has been found that any of them can be used for a photosensitive solder resist having plating resistance.

On the other hand, a comparison was made between 2,3-, 4-, and 6-functional aliphatic unsaturated compounds and bisphenol A-based aromatic bifunctional acrylates as liquid polyfunctional unsaturated compounds at room temperature. As shown in Table 9, it is found that a resist satisfying all the characteristics can be obtained when the added amount of the unsaturated compound is 5 to 30 parts by weight, preferably 10 to 30 parts by weight, more preferably 10 to 20 parts by weight. Was. It was also found that when the amount of addition was insufficient, the crosslinking at the time of exposure was insufficient, and the resist swelled during development, and when the amount of addition was excessive, difficulty was encountered in the adhesion exposure property.

Furthermore, it was also found that the larger the number of functional groups of the unsaturated compound, the wider the appropriate range of the amount added. From this viewpoint, the number of functional groups is desirably 2 or more, preferably 3 or more, and it has also been found that hexafunctional aliphatic acrylates are the most excellent.

Example 16 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 10, and the characteristics 1) to 9) were determined. Table 11 shows the results.

[0180]

[Table 10]

[0181]

[Table 11]

In this example, the effects of the photopolymerization initiator, UV absorber and pigment on the characteristics of the photosensitive solder resist were determined.

From the results in Table 11, it can be seen that the resist containing no phthalocyanine green pigment at all contained U in the resist.
It was found that the transmittance of V light was too large and the show-through resistance was insufficient. In order to improve the show-through property, a pigment such as phthalocyanine green having a UV absorbing action is used.
It was also found that about 0.2 parts by weight or more should be added to the resist.

The photopolymerization initiator was benzophenone or 4,4
4'-bis (N, N'-diethylamino) benzophenone, 2-methyl-1- {4- (methylthio) phenyl} -2-morpholino-1-propane-1, benzoin alkyl ether, thioxanthone derivative and dimethylaminobenzoic acid It has been found that various radical-generating photopolymerization initiators such as esters are suitable. It was also found that the optimal amount of the photopolymerization initiator was about 2 to 12 parts by weight. When the photopolymerization initiator having a UV absorbing action is insufficient, the UV transmittance of the resist is increased, the show-through property is difficult, and the alkali resistance of the resist is also deteriorated due to insufficient crosslinking at the time of UV exposure.

Further, it has been found that the UV absorbing action of the pigment and the photopolymerization initiator can be compensated to some extent by the addition of the UV absorbing agent. That is, it was also found that by adding a UV absorber such as 4-t-methoxybenzoylmethane to the resist, the show-through resistance can be improved even when no pigment is contained.

Example 17 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 12, and the characteristics 1) to 9) were determined. Table 13 shows the results.

[0187]

[Table 12]

[0188]

[Table 13]

In this example, the effect of the type and amount of the epoxy resin on the characteristics of the resist was determined. Epicoat 828 and Epicoat 10 which are bisphenol A type epoxy resins
01 and Epicoat 152 and Epicoat 154 which are phenol novolak epoxy resins, resists were prepared and their characteristics were examined.

The results are shown in Table 13, and it was found that good properties were obtained using any of the epoxy resins. It is also found that the compounding amount is optimally 5 to 40 parts by weight. If the amount is insufficient, the plating resistance is not sufficient, and if it is excessive, the adhesion exposure property is difficult.

Example 18 A photosensitive solder resist composition having plating resistance according to the present invention was prepared according to Table 14, and the characteristics 1) to 9) were determined. Table 15 shows the results.

[0192]

[Table 14]

[0193]

[Table 15]

In this example, the relationship between the compounding amounts of the antifoaming agent and the organic solvent and the characteristics was examined.

As shown in Table 15, silicone oil S
The antifoaming agent such as H-203 is preferably used in an amount of 0.5 to 10 parts by weight. If the amount is insufficient, it is found that bubble removal during printing is poor and the applicability is poor.

It has also been found that the amount of the organic solvent such as cellosolve acetate and carbitol is preferably 50 to 100 parts by weight. It was also found that if the amount of the organic solvent was insufficient, the coatability was poor, and if the amount was excessive, the viscosity of the resist ink was too low, making printing difficult.

[0197]

[Table 16]

[0198]

[Table 17]

[0199]

(1) As described above, the printed circuit board of the present invention is structurally formed of a metal plating having a copper etching solution resistance such as nickel plating having good adhesion to the base of the copper plating 7 in the through hole. Since the coating 4 is coated, the peel strength of the copper plating 7 is high, and the blisters in the holes are hardly generated, so that the reliability in the through holes is remarkably improved.

(2) In the manufacturing process, as described with reference to FIG. 7, while the inside of the through hole 2 is protected by a metal plating 4 having a resistance to a copper etchant such as nickel plating, a circuit pattern is formed by a resist mask 5. Therefore, even if a defective portion 8a of the resist mask is formed in the through hole 2 due to insufficient exposure, the metal plating 4 having a copper etching resistant property such as the underlying nickel plating is used as the etching solution for forming the circuit pattern. On the other hand, since it has etching resistance, it is possible to form a high-resolution fine line pattern without impairing the reliability of the through hole.

(3) By changing the etching resist from a conventional dry film to an electrodeposition resist, the width of the conductor pattern that can be formed is reduced from 100 μm to 50 μm.
The number of pattern wirings between 2.54mm grids is 3-5 to 5-9
Densified into books (FIG. 18).

(4) Since etching is performed while protecting the inner peripheral surface of the through hole with nickel, a highly reliable through hole can be formed. Also, in the conventional dry film, a land 9a for fixing the dry film 19 is always necessary to protect the through hole in the tenting state as shown in FIG. 19A. Since this is not required as shown in FIG. 2B, the landless through hole 18 shown in FIG. 20 can be formed, and the pattern wiring density can be improved.

(5) By coating nickel on the conductor surface of the substrate surface layer pattern and the inner layer pattern, it is possible to suppress the deterioration of insulation due to electrolytic corrosion of copper, so that the conductor gap can be reduced from the conventional 130 μm to 50 μm. The pattern wiring density can be improved.

Further, in the surface pattern of the substrate, the adhesion to the applied solder resist is improved, so that the pattern can be made ultra-fine.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view showing the appearance of a printed wiring board according to one embodiment of the present invention.

FIG. 2 is a schematic view illustrating a manufacturing process of a printed wiring board according to one embodiment of the present invention.

FIG. 3 is a schematic view illustrating a manufacturing process of a printed wiring board according to one embodiment of the present invention.

FIG. 4 is a schematic view showing a manufacturing process of a printed wiring board according to one embodiment of the present invention.

FIG. 5 is a partially sectional perspective view showing the appearance of a conventional printed wiring board.

FIG. 6 is a schematic view showing a circuit forming step using a conventional electrodeposition resist.

FIG. 7 is a schematic process diagram illustrating an operation in a through hole when a circuit is formed according to the present invention.

FIG. 8 is an explanatory diagram of a circuit forming step by a solder plating method.

FIGS. 9A and 9B are external views showing a pattern formation state using a film type resist and an electrodeposition type resist, respectively.

FIG. 10 is a schematic sectional view showing in-hole exposure of a through hole when an electrodeposition type resist is used.

FIG. 11 is a partial cross-sectional perspective view showing the appearance of a printed wiring board according to one embodiment of the present invention.

FIG. 12 is a partially sectional perspective view showing the appearance of a printed wiring board according to one embodiment of the present invention.

FIG. 13 is a partial cross-sectional perspective view showing the appearance of a printed wiring board according to one embodiment of the present invention.

FIGS. 14A and 14B are pattern cross-sectional views showing the mechanism of solder resist peeling before (a) heat treatment and (b) after heat treatment.

FIG. 15 is a pattern cross-sectional view showing a mechanism of electrolytic corrosion of copper.

FIG. 16 is a potential-pH state diagram of copper and nickel.

FIG. 17 is an enlarged view of an interface between a solder resist and a nickel layer.

FIG. 18 is a partial cross-sectional perspective view showing the appearance of a printed wiring board in which the pattern wiring densities of (a) 3 / 5ch substrate and (b) 5 / 9ch substrate are compared.

FIG. 19 is a partial cross-sectional perspective view showing the appearance of a printed wiring board in which the protection state of through holes during etching of (a) a dry film and (b) an electrodeposition resist is compared.

FIG. 20 is a partial cross-sectional perspective view showing the appearance of a printed wiring board having (a) through holes with lands and (b) landless through holes.

FIG. 21 is a cross-sectional view showing a manufacturing sequence of a part-reactive printed circuit board according to the present invention.

FIG. 22 is an X-ray diffraction pattern of a normal copper plating film obtained when a part-reactive printed circuit board is manufactured using the photosensitive solder resist composition having plating resistance according to the present invention.

FIG. 23 is an X-ray diffraction diagram of an abnormal copper plating film obtained when a part-reactive printed circuit board is manufactured using an inappropriate resist composition.

FIG. 24 is a view showing the upper limit of the amount of the melamine derivative of the present invention obtained from the quality of a copper plating film.

FIG. 25 is a diagram showing differences in quality of the melamine derivative of the present invention obtained from the relationship between resist load and copper plating film quality.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Copper-clad laminated board, 1a ... Multi-layer copper-clad laminated board with an inner layer circuit, 2 ... Through-hole, 2a ... Inner-layer through-hole, 3 ... Catalyst, 4 ... Nickel plating, 5 ... Electrodeposition resist, 6 ... Solder resist, 7 ... copper plating, 7a ... copper plating defective part, 8 ... etching resist, 8a ... resist defective part, 9 ... surface circuit pattern, 9a ... land part, 10 ... exposure, 11 ... film type photosensitive resist, 12 ... positive mask (circuit 13: Solder plating, 14: Plating resist, 15: Bulging in the hole, 16: Connection terminal for mounting parts, 17: Hydrogen bonding part, 18: Landless through hole, 19: Dry film, 20: Solder resist peeling part 23: Lack of resist resolution, 24: Poor resist adhesion.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H05K 3/28 H05K 3/28 C 3/42 650 3/42 650C 3/46 3/46 N (72) Inventor Masahiro Furukawa Kanagawa 216, Totsuka-cho, Totsuka-ku, Yokohama-shi, Hitachi, Ltd.Information and Communication Division, Hitachi, Ltd. (72) Inventor Akiyoshi Tsunoya 216, Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture, Ltd. Ryozo Sato 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the information and communication division of Hitachi, Ltd. (72) Inventor Matsutoshi 216, Totsukacho, Totsuka-ku, Yokohama, Kanagawa Prefecture Inside the information and communication division of Hitachi, Ltd. ) Inventor Naoya Matsuzaki 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Information and Communication Division, Hitachi, Ltd. (72) Inventor Hiroshi Kikuchi Yokohama, Kanagawa Prefecture 292, Yoshida-cho, Totsuka-ku, Ltd.Hitachi, Ltd., Production Technology Laboratory (72) Inventor Makio Watanabe 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa, Japan 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside of Hitachi, Ltd. Production Engineering Laboratory (56) References JP-A-3-6880 (JP, A) JP-A-58-56495 (JP, A) JP-A-3 −254181 (JP, A) JP-A-2-10889 (JP, A) JP-A-4-136857 (JP, A) JP-B-3-2358 (JP, B2) (58) Fields investigated (Int. . ^6, DB name) H05K 1/11 H05K 3/28 H05K 3/42 650

Claims (14)

(57) [Claims] 1. A circuit pattern including a step of forming a through hole in a copper-clad laminate substrate, a step of forming a conductor layer in the through hole, and a land formed on a periphery of the through hole opening on the substrate. Forming a conductive layer in the through-hole, wherein the first step of forming the conductor layer in the through-hole is performed by copper-resistant etching on the entire surface of the substrate including the inside of the through-hole. After forming the metal plating having the liquid property, the metal plating having the copper etching liquid resistance formed on the substrate surface is removed by mechanical polishing, and the metal plating having the copper etching liquid resistance only in the through holes is formed. The step of forming and the step of forming a circuit pattern including the land are performed by coating a photosensitive resist composed of an electrodeposition type UV resist on the entire surface and a predetermined circuit pattern is drawn. Exposure through a mask, phenomena treatment to form an etching resist mask pattern, use this resist mask pattern to selectively etch the copper foil on the substrate, peel off the resist mask pattern,
Removing and forming a circuit pattern including lands;
A second step of forming a conductor layer in the through hole
A copper plating coating from the metal plating having the copper etchant resistance formed in the through hole to at least the land of the opening, and the metal plating having the copper etchant resistance in the through hole, A method for manufacturing a printed wiring board, comprising a step of forming a conductor layer composed of a double layer with copper plating coated thereon. 2. A circuit pattern including a step of forming a through-hole in a copper-clad laminate substrate, a step of forming a conductor layer in the through-hole, and a land formed on the periphery of the through-hole opening on the substrate. Forming a conductive layer in the through-hole, the step of forming a conductive layer in the through-hole, nickel plating on the entire surface of the substrate including the inside of the through-hole After the formation, the nickel plating formed on the substrate surface is removed by mechanical polishing, and the nickel plating is formed only in the through holes, and the step of forming a circuit pattern including the land is performed by an electrodeposition type UV resist. Is coated on the entire surface with a photosensitive resist consisting of Using the resist mask pattern, selectively etch the copper foil on the substrate, peel off the resist mask pattern,
Removing and forming a circuit pattern including lands;
A second step of forming a conductor layer in the through hole
A conductive layer comprising a double layer of nickel plating in the through hole and copper plating coated thereon, from the nickel plating formed in the through hole to at least the land of the opening. Forming a printed wiring board. 3. The method according to claim 1, wherein said nickel plating is 20 μm.
3. The method for manufacturing a printed wiring board according to claim 2, further comprising the following pre-process of depositing copper plating. 4. A through hoe having a conductor layer disposed on an inner peripheral surface thereof.
Printed with a circuit pattern on the base and the base surface
In the wiring board,  The conductor layer in the through hole has copper etchant resistance.
Metal plating underlayer, and the circuit pattern
Copper foil covered at least up to the land
It consists of a double layer of
The solder resist is coated on the circuit board except the part
The above solder resist is a solid polyfunctional at room temperature.
Unsaturated compounds and polyfunctional unsaturated compounds that are liquid at room temperature
And a photopolymerization initiator,EpoxyResin and epoxy resin
Light comprising a curing agent and melamine or a derivative thereof
Pudding characterized by using a curable resist composition
Wiring board. 5. A printed wiring board comprising a through hole in which a conductor layer is disposed on an inner peripheral surface and a circuit pattern disposed on a substrate surface, wherein the conductor layer in the through hole is nickel-plated, and The circuit pattern is formed by a double layer of copper plating integrally covered up to at least a land portion, and a solder resist is coated on a circuit board excluding the through holes and the land portion, and the solder resist is formed. in a solid polyfunctional unsaturated compound at room temperature, and a liquid polyfunctional unsaturated compound at room temperature, and a photopolymerization initiator, Epo
A printed wiring board using a photocurable resist composition comprising a xy resin, a hardening agent for a modified epoxy resin, and melamine or a derivative thereof. 6. The polyfunctional unsaturated compound which is solid at room temperature is a prepolymer of diallyl phthalate, and is a polyfunctional unsaturated compound or a polyfunctional acrylate or methacrylate compound which is liquid at room temperature. The printed wiring board according to claim 4 or claim 5. 7. The method according to claim 1, wherein the molecular weight of the diallyl phthalate prepolymer is 3,000 to 30,000, and the polyfunctional unsaturated compound which is liquid at room temperature has at least three functional groups of a polyfunctional acrylate or methacrylate compound. The printed wiring board according to claim 6. 8. The printed wiring board according to claim 4, wherein the melamine or a derivative thereof is a compound having a diaminotriazine skeleton. 9. The printed wiring board according to claim 4, wherein the melamine or a derivative thereof has a solubility in water of 1 wt% or less. 10. The printed wiring board according to claim 4, wherein the curing agent for the epoxy resin is a derivative of imidazole. 11. The melamine or a derivative thereof and d
The printed wiring board according to claim 4 or 5, wherein the curing agent of the oxy resin is one that is acted on by a common compound. 12. The melamine or a derivative thereof is melamine, 2,4-diamino-6-methyl-s-triazine, 2,4-
Diamino-6-phenyl-s-triazine, 2,4-diamino-6-
The printed wiring board according to claim 4, wherein the printed wiring board is selected from hydroxy-s-triazine. 13. The compound 2,4-diamino -6 {2 '- methylimidazole - (1')} ethyl -s- triazine, 2,4-diamino -6 {2 '- ethyl-4' - methyl Imidazole (1 ' )} ethyl
-s-triazine, 2,4-diamino-6 {2-undecylimidazole (1 ' )} ethyl-s-triazine, 2,4-diamino-6
{2'-phenylimidazole (1 ' )} ethyl-s-triazine or 2,4-diamino-6 {2'-methylimidazole (1 ' )} ethyl-s-triazine / isocyanuric acid adduct The printed wiring board according to claim 11, wherein 14. The printed circuit board according to claim 11, wherein said compound is present in an amount of 1 to 20 parts by weight based on 100 parts by weight of the diallyl phthalate prepolymer.