JPH0521912A - Printed circuit board - Google Patents

Abstract

PURPOSE:To improve adhesive properties among each circuit and an electromagnetic wave shielding layer and the adhesive properties of each circuit and the electromagnetic wave shielding layer, and to enhance the conductivity of each circuit while preventing bleeding at the time of printing in a printed circuit board, in which a jumper circuit and the electromagnetic wave shielding layer are connected to a circuit pattern through a through-hole circuit, CONSTITUTION:Metallic copper powder, surfaces of which are coated with titanate, zirconate or a mixture thereof, a resol phenolic resin, a thixotropic conditioner, an amino compound and a chelate layer forming agent are blended as a conductive coating material forming a through-hole circuit 20. Metallic copper powder, surfaces of which are coated with titanate, zirconate or the mixture thereof, resol type phenol, a chelate forming agent, an adhesive property improver and a conductivity improver are compounded as a conductive coating material forming a jumper circuit 7 and an electromagnetic wave shielding layer 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board having a jumper circuit, a through-hole circuit and an electromagnetic wave shield layer formed by a conductive paint in which a metallic copper powder is dispersed in a phenol resin mixture.

[0002]

2. Description of the Related Art Conventionally, IC, MSI,
Copper-clad laminated insulating substrates are often used as substrates for printed circuits on which LSIs and the like are mounted.

In the printed circuit formed on this copper clad laminated insulating substrate, for example, a jumper circuit for bypass is provided in order to reduce the self-inductance, the straight capacity, the common impedance, etc. related to the length of the pattern. . In this jumper circuit, after a resist layer is formed on the entire non-connected circuit portion between copper foil circuits in a printed circuit, conductive silver paint is applied between copper foil circuits that should be connected by jumping over the portion where the resist layer is formed. (Hereinafter, referred to as silver paste) is formed by a screen printing method.

An electromagnetic wave shield layer is formed on the copper foil circuit except for a part of the ground pattern or the power supply pattern, with a solder resist layer interposed therebetween. This electromagnetic wave shield layer is also formed using silver paste.

Further, in the case where a printed circuit is formed on the front and back of the substrate or the printed circuits are laminated via an insulating layer, and when it is necessary to connect the circuits above and below the printed circuit, through holes are formed in the substrate or the resist layer. Form a circuit. This through-hole circuit also uses silver paste.

However, since silver paste is expensive, various inexpensive conductive copper paints (hereinafter referred to as copper pastes) have been published as alternatives to these, but these copper pastes are mainly used as binders in thermosetting phenol-based paints. Since a resin is used, the adhesiveness to the copper foil surface is poor due to internal stress during thermosetting of the coating film, and the reliability is not sufficient when it is used as a conductive paint for forming the jumper circuit or the like.

Therefore, the inventors of the present invention previously proposed a conductive paint having good adhesion to the copper foil surface, low cost, excellent conductivity, and good solder heat resistance (Japanese Patent Laid-Open No. 2-16172).
issue).

However, although the cured film formed of this conductive paint can obtain good adhesion to the copper oxide foil surface,
Difficult to adhere to the surface of non-oxidized copper foil. Low adhesion means low conductivity. Moreover, since the viscosity is low, a sufficient film thickness cannot be obtained when forming a through-hole circuit, and therefore there is a problem in terms of conductivity. In addition, bleeding occurs during printing, which is a workability problem.

An object of the present invention is to provide a conductive paint having excellent adhesion to both copper oxide and non-copper oxide copper foil surfaces and a through-hole connection in which a good connection state can be obtained with sufficient conductivity. Electromagnetic wave shield layer, jumper circuit, with conductive paint that does not cause bleeding during printing
The printed circuit board has a through-hole circuit.

[0010]

In order to solve the above problems, according to the present invention, at least one layer of a circuit pattern including a ground pattern, a resist layer and an electromagnetic wave shield layer is provided on at least one surface of the substrate, and the substrate In a well-known printed circuit board having a through-hole circuit in at least one of the resist layer and a jumper circuit in the circuit pattern, the electromagnetic wave shield layer or the electromagnetic wave shield layer and the jumper circuit are formed by the following conductive paint a,
The jumper circuit and the through-hole circuit or the through-hole circuit are formed by the following conductive paint b.

[Conductive paint a: blending of the following respective components (A) to (E)] (A) Copper metal powder 1 surface-coated with 0.05 to 0.2 parts by weight of titanate, zirconate, or a mixture thereof.
00 parts by weight (B) Resol type phenolic resin 5 to 30 parts by weight (C) Chelate layer forming agent 0.5 to 4 parts by weight (D) Adhesion improver 0.1 to 5 parts by weight (E) Conductivity improver 0.5 to 7 parts by weight [conductive coating b: blending of the following respective components (F) to (J)] (F) surface coated with 0.05 to 0.2 parts by weight of titanate, zirconate, or a mixture thereof, Metal copper powder 1
00 parts by weight (G) 2-1 substitution product, 2,4-2 substitution product, 2,4,6-
When the infrared transmittances of the 3-substituted product, the methylol group, the dimethylene ether, and the phenyl group are 1, m, n, a, b, and c, (b) l / n = 0. 8 to 1.2 (b) m / n = 0.8 to 1.2 (c) b / a = 0.8 to 1.2 (d) c / a = 1.2 to 1.5 Resol type phenolic resin 5 to 33
Parts by weight (H) chicken tropic modifier 0.5-4 parts by weight (I) amino compound 0.5-3.5 parts by weight (J) chelate layer forming agent 3.0-10 parts by weight The distribution ratio shows the amount of metal copper powder as 100 parts by weight (hereinafter the same).

The substrate material is an insulating material such as epoxy resin, phenol resin, glass fiber or ceramics.

The resist layer material can be screen-printed with a synthetic resin such as an epoxy resin, an epoxy-melamine resin, polyurethane, butyl rubber, or a silicone elastomer as a liquid coating material, and as a film-shaped material, it is the same as the above-mentioned substrate. The thing of what is used is stuck by a roll laminator etc.

The metallic copper powder may have any shape such as flakes, dendritic shapes, spherical shapes, and irregular shapes. Particle size is 10
It is preferably 0 μm or less, and particularly preferably 1 to 30 μm.
Particles having a particle size of less than 1 μm are easily oxidized and the resulting coating film has a reduced conductivity, which is not preferable.

The metallic copper powder is titanate, zirconate, or a mixture thereof (hereinafter referred to as dispersibility-imparting agent).
The surface coating of the resin promotes fine dispersion in the resin mixture, thereby stabilizing the quality of the conductive paint and improving the conductivity. The amount of the dispersibility-imparting agent added is 0.05 to 0.2 parts by weight with respect to 100 parts by weight of the metallic copper powder. When the amount of the dispersibility-imparting agent added is less than 0.05 part by weight, the conductivity of the coating film decreases, and when it exceeds 0.2 part by weight, the adhesion with the copper foil and the solder heat resistance are not preferable. .
The dispersibility-imparting agent may be added alone, or the solvent may be removed after being added as a solution. Incidentally, this surface treatment makes it unnecessary to add a dispersant.

The above-mentioned resol type phenol resin may be a usual one for the conductive paint a, but the conductive paint a may have the same composition as the conductive paint b. When the content is less than 5 parts by weight, the metallic copper powder is not sufficiently bound and the resulting coating film becomes brittle. Further, when it exceeds 30 parts by weight, the conductivity is lowered. It is preferably 9 to 20 parts by weight.

With respect to the resol type phenol resin used for the conductive paint b, its chemical amount, 2-1 substitution amount is λ,
The amount of 2,4-2 substitution product is μ, the amount of 2,4,6-3 substitution product is ν, the amount of methylol group is α, the amount of dimethylene ether is β,
When the amount of phenyl group is γ, 1 / n and m / n of the above-mentioned constitution
Is large, it means that λ / ν and μ / ν are small. That is, the amount of 2-1 substitution product λ, 2,4-2
This means that the amount of 2,4,6-3 substitution product ν is larger than the substitution product amount μ. In addition, b / a, c /
A large a means that β / α and λ / α are small. That is, it means that the amount of methylol groups α is larger than the amount of dimethylene ether β and the amount of phenyl groups λ.

Generally, when the 2,4,6-3 substitution product amount ν increases, the crosslink density of the resol-type phenol resin increases, so that the smaller λ / ν and μ / ν, that is, 1 / n. , M / n is larger, the conductivity of the coating film is better. However, on the contrary, the coating film tends to be hard and brittle, and the physical properties deteriorate. If β / α is small, the solderability of the coating film is poor, and if γ / α is large, the conductivity of the coating film is poor.

Therefore, in the obtained conductive coating material b, the resole type phenolic resin having appropriate hardness of the coating film and having both good conductivity and solderability is shown as 1 / n, m / n and b / a are 0.8 to 1.2 and c /
It is suitable that a is 1.2 to 1.5.

The chelate layer forming agent is at least one selected from aliphatic amines such as monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethylenediamine and triethylenetetramine.
It is a seed. The chelate layer forming agent prevents oxidation of the metal copper powder and contributes to maintaining conductivity. The content of the conductive coating a is 0.5 to 4 with respect to 100 parts by weight of the metal copper powder.
Parts by weight, preferably 1 to 3.5 parts by weight. 0.5
When it is less than the weight part, the conductivity of the coating film is lowered. On the contrary, when it exceeds 4 parts by weight, the solder heat resistance is not preferable. On the other hand, the conductive coating material b is compounded in an amount of 3.0 to 10 parts by weight with respect to 100 parts by weight of the metal copper powder. If the blending amount is less than 3.0 parts by weight, the conductivity of the coating film will decrease, and conversely, if it exceeds 10 parts by weight, the conductivity of the coating film will also decrease.

The adhesiveness improver includes various adhesives. As a natural resin type, rosin (gum type,
Tall oil type, wood type, rosin derivative, terpene resin type (terpene type, terpene phenol type) and the like are preferable. Synthetic resin-based materials include thermosetting materials such as petroleum resin-based, butyral resin-based, phenol resin-based, and xylene resin-based materials, thermoplastic materials such as vinyl acetate resin, acrylic resin, cellulose, phenoxy resin, and recycled materials. Synthetic rubbers such as rubber, styrene butadiene rubber, nitrile rubber and butyl rubber are preferred. These have a property of lowering the internal stress of the resol-type phenol resin as a binder, or have a functional group (carboxyl group, hydroxyl group, long-chain alkyl group, etc.) that exhibits adhesiveness. When the amount of the adhesion improver is less than 0.1 part by weight, the improvement of the adhesion is not observed, and when it exceeds 5 parts by weight, the conductivity is lowered.

The conductivity improver is composed of a nitrogen-containing compound having a phenyl group or a heterocyclic compound,
In particular, compounds capable of exhibiting conductivity by chemical oxidative polymerization or electrolytic polymerization are preferable.

Specific examples include aniline, diphenylamine, N-phenyl-p-phenylenediamine, N,
N'-diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl, p-phenylenediamine,
N, N'-diphenylbenzidine, aminophenol,
Alkylated toluenediamines such as diaminophenol, 5-t-butyl-3,4-toluenediamine or 5-isopropyl-2, -4-toluenediamine, p
-Phenylenediamine, 1,5-naphthalenediamine,
Cyclohexyl-p-phenylenediamine, ortho-tolyl-β-naphthylamine, O-anisidine, 4,5-
Compounds having amino groups such as diamine, aminopyrene, chrysazine, diaminonaphthalene, pyrrole, amphoteric polypyrrole, thiophene, α-bipyrrole, 3-methylthiophene, phthalocyanine, phthalocyanine metal complex, furan, selenophene, erlophen, tetrathiofulvalene, Examples thereof include, but are not limited to, tetracyanoquinodimethane.

If the amount of these conductivity improvers is less than 0.5% by weight with respect to the metal copper powder, no improvement in conductivity is observed (in terms of volume resistivity, 1 × 10 ⁻⁴ Ω · cm or more). When the amount of the conductivity improver exceeds 7 parts by weight, the conductivity is saturated and no further improvement in conductivity is observed, and the content of the compound having an amino group is high. In this case, gelation proceeds and the pot life becomes short, which is not preferable. In addition, the adhesion to the copper foil surface is also reduced.

The conductive paint b contains 0.5 to 4 parts by weight of a thixotropic adjusting agent. This thixotropic adjuster is intended to eliminate bleeding during printing. The adjusting agent is at least one selected from polyvinyl butyral resin, polyvinyl formal resin, acrylic resin, paravinylphenol resin and the like. The blending amount of this regulator is 0.5 to 4 parts by weight with respect to 100 parts by weight of the metal copper powder. When this adjusting agent is less than 0.5 parts by weight, the bleeding cannot be improved,
On the contrary, when it exceeds 4 parts by weight, the conductivity of the coating film is remarkably lowered. This thixotropic adjusting agent can be contained in the conductive coating material a in the same amount.

The amino compound of the conductive paint b acts as a reducing agent in addition to the conductivity improver and prevents oxidation of the copper metal powder,
Contributes to maintaining conductivity. The compounding amount is 10 copper metal powders.
It is 0.5 to 3.5 parts by weight with respect to 0 parts by weight. If the blending amount is less than 0.5 parts by weight, the conductivity of the coating film is remarkably reduced. On the other hand, if it exceeds 3.5 parts by weight, the conductivity is saturated and no further improvement is observed. The thixotropic property S suitable for a through-hole circuit cannot be maintained.

Specific examples of the amino compound include aniline, diphenylamine, phenylenediamine, diaminonaphthalene, anisidine, aminophenol, diaminophenol, acetylaminophenol, aminobenzoic acid, N, N-diphenylbenzidine, and the like. There are several types, but the present invention is not limited thereto.

The conductive paints a and b according to the present invention include
In order to adjust the viscosity, a usual organic solvent can be used appropriately. For example, known solvents such as cellosolve acetate, carbitol, butyl carbitol, and butyl cellosolve acetate.

[0029]

As can be understood from the above description, the conductive paints a and b in the printed circuit board having the above structure have excellent conductivity of the coating film and adhesion of the coating film to the copper foil surface, The solder heat resistance of the film is excellent. In particular, the conductive coating material b is suitable as a through-hole circuit because the coating material has high conductivity even if the viscosity is low.

[0030]

EXAMPLES First, the conductive coating material a was prepared by charging 100 parts by weight of dendritic metal copper powder having a specific surface area of 0.4 m ² / g or less with a particle size of 5 to 10 μm and a hydrogen reduction loss of 0.25% or less into a stirrer, The titanate was added little by little and stirred to coat the surface of the metallic copper powder with the titanate. Then, this copper metal powder was mixed and kneaded with a resol type phenol resin, a chelate layer forming agent, an adhesion improver and a conductivity improver so as to have the composition shown in Table 1, and a little butyl carbitol as a solvent. In addition, the mixture was kneaded with a triaxial roll for 20 minutes to obtain an appropriate viscosity.

[0031]

[Table 1]

The conductive coating material b is similar to the conductive coating material a in that the same quality of dendritic metal copper powder is coated with titanate, and then the metal copper powder is coated with a reducing agent such as aminophenol and a chelate layer forming agent. Triethanolamine, the resol type phenol resin of JP-A-2-16172, and a polyvinyl butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.), which is a thixotropic modifier, are mixed at the ratios shown in Table 2, respectively, and as a solvent, A mixed solvent of ethyl carbitol and butyl cellosolve was added, and the mixture was kneaded in place with a triaxial roll for 20 minutes, and the viscosity was adjusted to 20 P using a measuring machine VT-04 manufactured by Rion.

In place of ethyl carbitol or butyl cellosolve, known ones such as butyl carbitol, butyl carbitol acetate, butyl cellosolve acetate, methyl isobutyl ketone, toluene and xylene can be used.

[0034]

[Table 2]

On the other hand, as shown in FIG. 1, a circuit pattern of copper foil is first formed on the surface of the glass / epoxy substrate 1. The circuit pattern includes signal line patterns 2, 2 ′, signal lands 3, 3 ′, 3 ″, a power supply pattern 4 and a ground pattern 5. Each of these patterns is formed by a known photolithography technique.

The first pattern having the through holes 20 is formed on the signal line patterns 2 and 2 ′ between the signal lands 3 3 ′ and 3 ″ which are the lands of a predetermined circuit to be connected to form a required pattern. The resist layer 6 is provided, and the through hole 2
A conductive paint b is embedded in the hole 0 to form a through hole circuit, and a jumper circuit 7 for connecting the signal lands 3, 3'and 3 '' through the through hole circuit 20 is formed thereon with the conductive paint b. After that, ground pattern 5
The undercoat layer 8 is formed while leaving a part of the region A (through hole). The undercoat layer 8 is a solder resist layer made of a resin insulating material. The region A where the ground pattern 5 is exposed is preferably formed in the largest possible area of the substrate, but at least 1
There should be a place. A conductive paint b is applied to the through holes in the region A to form a through hole circuit 20, an electromagnetic wave shield layer 9 is formed thereon by the conductive paint a, and an overcoat layer 10 is formed by a resin insulating material. To do.

The resist layer 6 and the through hole circuit 2 described above.
0, the jumper circuit 7, the undercoat layer 8, the electromagnetic wave shield layer 9, and the overcoat layer 10 are formed by screen printing. The formation of the through hole at that time masks the device portion.

In the above embodiment, both the jumper circuit 7 and the electromagnetic wave shield layer 9 are made of the conductive paint b through hole circuit 20.
Although it was connected to the circuit patterns 3 ', 5 via the through hole circuit 20 on the side of the jumper circuit 7 as shown in FIG.
May be formed with the conductive paint a at the same time when the jumper circuit 7 is printed. At this time, as shown in FIG. 3, the entire jumper circuit 7 can be printed with the conductive paint b. On the contrary, as shown in FIG. 4, the through-hole circuit 20 on the side of the electromagnetic wave shield layer 9 may be formed of the conductive paint a at the same time as the printing of the layer 9. At this time, as shown in FIG. 5, the entire jumper circuit 7 can be printed with the conductive paint b.

As the through-hole circuit 20, there are cases where circuits on both surfaces of the substrate 1 are connected, or circuits laminated via resist layers are connected.
Also, the conductive paint b is used.

Whether or not to use the conductive paint b is determined based on the size and depth of the through hole, and other paints, such as the conductive paint a, can provide sufficient conductivity and penetration into the through hole. Whether or not to make an appropriate judgment.

The superiority of the printed circuit board P of each of the above-described embodiments can be understood by the following tests.

That is, the solder resist is printed and cured on the glass epoxy substrate by the screen printing method using the conductive paint a, and the width is 1 mm and the thickness is 25 ±.
Screen printing of 5 conductive circuits of 5 μm and length of 60 mm using a 180 mesh Tetoron screen,
The coating film was cured by heating at 160 ° C. for 30 minutes using an air oven. The volume resistivity of this coating film was measured to evaluate the conductivity of the coating film. The results are shown in Table 1.

On the other hand, after cleaning the copper foil surface of the copper clad laminated insulating substrate, a conductive coating a is used to form a coating film of 50 mm × 50 mm on the copper foil surface by screen printing.
After heat-curing the coating film in the same manner as described above, JIS K54
In accordance with the cross-cut test method of 00 (1990), 11 parallel and 11 vertical and horizontal parallel lines are drawn on the coating film at intervals of 1 mm so that 100 squares can be formed in 1 cm ^2. -Shaped cuts, and when the coating film is peeled off from it using cellophane tape, the number of cross-cuts of the coating film remaining on the copper foil surface is obtained, and the adhesion of the coating film on the copper foil surface is evaluated. did. Table 1
In, the number of grids of the coating film remaining on the copper foil surface is 100
The case is shown by a circle, and the case of 99 or less is shown by a cross.

Regarding the solder heat resistance of the coating film, a test piece shown in FIG. 6 was formed by the following method, the test piece was immersed in a molten solder bath at 260 ° C. for 60 seconds and pulled up, and then the surface condition was observed. And evaluated. In Table 1, the case where there is unevenness due to thermal deformation on the surface is indicated by a cross, and the case where there is no unevenness is indicated by a circle.

Method of preparing test piece (see FIG. 6) (1) Solder resist cured film is formed on the glass / epoxy substrate 11 by screen printing using a solder resist ink so as to partially overlap the copper foil 12. 13 is formed. (Curing conditions: 160 ° C., 30 minutes) (2) The copper paste cured film 14 is formed on the copper foil 12 and the solder resist cured film 13 by the screen printing method using the conductive paint a. (Curing conditions: 160 ° C,
30 minutes) (3) A solder resist cured film 15 is formed on the copper paste cured film 14 by screen printing using a solder resist ink. (Curing conditions: 150 ° C,
30 minutes) As is clear from Table 1, in Examples 1 to 4, since the specific compounding materials used in the present invention are properly combined, the conductivity of the coating film, the copper foil surface and the coating film Excellent adhesion and solder heat resistance of the coating film.

On the other hand, in Comparative Example 1, the conductivity is not improved because the conductivity improver is too small, and in Comparative Example 2, the adhesion is deteriorated because the conductivity improver is too large.
In Comparative Example 3, since the adhesion improver is too small,
No improvement in adhesion was observed, and the conductivity was not improved because the amount of the conductivity enhancer was too small. Also, the solder heat resistance is poor because the amount of triethanolamine (chelate layer forming agent) is too large. In Comparative Example 4, since the amount of titanate was too large, the conductivity was good, but the adhesion with the copper foil was poor and the solder heat resistance was also poor. In Comparative Example 5, the amount of titanate is too small, and therefore the conductivity is poor. However, the adhesiveness to copper foil and solder heat resistance are not bad. In Comparative Example 6, the conductivity is poor because the amount of the resol-type phenol resin is too much. In Comparative Example 7, the conductivity is not improved because the adhesion improver is too much.

A zirconate was used in place of the titanate, and the same treatment as described above was carried out.
4, almost the same results as Comparative Examples 1 to 7 were obtained. However, the volume resistivity of the coating film in Example 1 was 0.7 × 10 ⁻⁴ Ω.
Although it was cm, when the zirconate was used in Example 1, the volume resistivity was 0.6 × 10 ⁻⁴ Ωcm.

When a similar test was conducted on the conductive paint b, the same effect was obtained. This is considered to be based on the similarity of composition.

Further, as for the conductive paint b, as shown in FIG. 7, the conductive paint b was applied to a paper phenol substrate 32 having a thickness of 1.6 mm by using a Tetoron screen of 80 mesh.
It was embedded in the through hole 33 (hole diameter 0.8 mm) by screen printing. Then, after drying at 25 ° C. ± 5 ° C. for 24 hours, it was heated at 160 ° C. for 30 minutes using an air oven to cure the coating film.

As shown in FIG. 8, the through hole 33 has 20 holes forming a row in the lateral direction, and a large number of such rows A to K are provided. On the front side of the substrate 32, two adjacent through holes 33, 33 ... Are connected by a copper foil 34 (see a in the figure), and on the front side two through holes are not connected by the copper foil 34. 33, 33 ... are copper foils 34 ', 3 on the back side.
4 '(see b).

Ends 41 to 42, 42 to 43, 43 to 44
The series resistance value of 20 holes in the interval was measured and divided by 20 to obtain the resistance value per hole. The results of evaluating the conductivity of the coating film b by this resistance value are shown in Table 2.

The presence or absence of bleeding was evaluated as follows. That is, 100 shots printed and exuded from the copper foil land portion were evaluated as "bleeding" and those not exuded from the copper foil land portion were evaluated as "unbleeded". In Table 2, those having no bleeding are indicated by ◯, and those having bleeding are indicated by x.

As is clear from this result, Example 5
In No. 7, the specific compounding materials used in the present invention are appropriately combined, and the coating film b has excellent conductivity.

On the other hand, in Comparative Example 8, since polyvinyl butyral is not blended, the conductivity is good, but bleeding occurs. In Comparative Example 9, since the polyvinyl butyral is too much, bleeding does not occur, but the conductivity is not good. Further, in Comparative Example 10, since polyvinyl butyral is blended in an appropriate amount, there is no bleeding, but since triethanolamine is small, the conductivity is remarkably lowered. Comparative Example 11 does not have aminophenol, and Comparative Example 12 has too much resol-type phenol resin, and thus has poor conductivity.

From the above test results, it can be understood that the printed circuit boards of the examples are excellent.

[0056]

Since the present invention is constructed as described above, the conductivity of the entire circuit is excellent, and bleeding hardly occurs during printing (printing).

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of one embodiment

FIG. 2 is a sectional view of a main part of another embodiment.

FIG. 3 is a cross-sectional view of a main part of another embodiment.

FIG. 4 is a sectional view of a main part of another embodiment.

FIG. 5 is a cross-sectional view of the essential parts of another embodiment.

FIG. 6 is a sectional view of a solder heat resistance test piece.

FIG. 7 is a sectional view of a resistance value test piece.

8A is a plan view of the test piece, and FIG. 8B is a schematic view of the back surface thereof.

[Explanation of symbols] P printed circuit board 1 substrate 2, 2'signal line pattern 3, 3 ', 3' 'signal land 4 power supply patterns 5 ground patterns 6 Resist layer 7 jumper circuit 8 Undercoat layer 9 Electromagnetic wave shield layer 10 Overcoat layer 20 through-hole circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 9/00 R 7128-4E W 7128-4E

Claims (2)

[Claims] 1. A circuit pattern including a ground pattern, a resist layer and an electromagnetic wave shield layer are provided on at least one surface of a substrate, and a through hole circuit is provided on at least one of the substrate and the resist layer, and the circuit pattern is A printed circuit board provided with a jumper circuit, wherein the electromagnetic wave shield layer and the jumper circuit are formed of the conductive paint a described below, and the through-hole circuit is formed of the conductive paint b described below. [Conductive coating a: Compounding of the following respective components (A) to (E)] (A) Copper metal powder 1 surface-coated with 0.05 to 0.2 parts by weight of titanate, zirconate, or a mixture thereof.
00 parts by weight (B) Resol type phenolic resin 5 to 30 parts by weight (C) Chelate layer forming agent 0.5 to 4 parts by weight (D) Adhesion improver 0.1 to 5 parts by weight (E) Conductivity improver 0.5 to 7 parts by weight [conductive coating b: blending of the following respective components (F) to (J)] (F) surface coated with 0.05 to 0.2 parts by weight of titanate, zirconate, or a mixture thereof, Metal copper powder 1
00 parts by weight (G) 2-1 substitution product, 2,4-2 substitution product, 2,4,6-
When the infrared transmittances of the 3-substituted product, the methylol group, the dimethylene ether, and the phenyl group are 1, m, n, a, b, and c, (b) l / n = 0. 8 to 1.2 (b) m / n = 0.8 to 1.2 (c) b / a = 0.8 to 1.2 (d) c / a = 1.2 to 1.5 Resol type phenolic resin 5-30
Part by weight (H) Chicken tropic modifier 0.5-4 parts by weight (I) Amino compound 0.5-3.5 parts by weight (J) Chelate layer forming agent 3.0-10 parts by weight 2. A circuit pattern including a ground pattern, a resist layer and an electromagnetic wave shield layer are provided on at least one side of a substrate, and a through hole circuit is provided on at least one of the substrate and the resist layer, and the circuit pattern is In a printed circuit board provided with a jumper circuit, the electromagnetic wave shield layer is formed by the conductive paint a according to claim 1, and the jumper circuit and the through hole circuit are formed by the conductive paint b according to claim 1. And printed circuit board.