JPH07176846A - Composition of conductor paste for filling via hole, both-sided and multilayered printed board using it, and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a low-viscosity and low-volatile conductor paste composition by dispersing a conductive filler having a specific ability in an epoxy resin having specific properties. CONSTITUTION:Conductor paste for filling via hole is composed of 80-92wt.% of a conductive filler having a mean particle diameter of 0.5-20mum and specific surface area of 0.1-1.5m<2>/g, 8-20wt.% of a liquid epoxy resin which has a cold viscosity of <=15Pa.sec and contains two or more epoxy groups, and 0.5-5wt.% of a hardening agent. The paste is prepared so that its viscosity can become <=2,000Pa.sec and the amount of volatile matters contained in the paste can become 42.0wt.%. When the viscosity is >2,000Pa.sec, the filling work of via holes becomes difficult and, when the amount of volatile matters is not 42.0wt.%, the volatile matters are volatilized at the time of heating and compressing the paste after filling a via hole with the paste, leaving voids in the filling structure of the via hole or causing the stripping off of prepreg.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a via-hole filling conductor paste composition, a double-sided printed board and a multilayer printed board using the same.

[0002]

2. Description of the Related Art In recent years, circuit boards have been required to have high multi-layers and high densities as electronic devices have become higher in performance and smaller in size.
It is known that a high density can be achieved by the inner via hole connection as a connection method between the layers of the substrate that can connect the ICs and the parts with the shortest distance. In through-hole connection such as used for general glass epoxy multilayer boards, it is difficult to connect only the necessary layers because the connection is made by plating the through-holes, and the electrode land is provided on the top layer of the board. Because of the structure, it is difficult to form the electrode land of the surface mount component in that portion, and it is difficult to increase the mounting density due to these restrictions. As a method to solve these problems, not a through hole but a method of opening a hole up to half of the board to reduce the through hole, or a method of filling the through hole with a conductor paste and further plating to close the hole in the uppermost layer of the board to reduce the mounting density. There is a method to improve
The manufacturing process becomes complicated, and cost and mass productivity become problems. On the other hand, in the inner via hole connection, it is possible to connect only each required layer, and there is no through hole in the uppermost layer of the substrate, and the mountability is excellent.

However, this connection method is applied to a resin substrate (for example,
In the example applied to a glass epoxy substrate), a double-sided substrate has a substrate in which a low-viscosity solvent-type silver paste is embedded in a through-hole by a printing method and dried to be hardened to make conduction, but its connection specific resistance value is 10 ^−. High as high as ³ Ω · cm, and poor reliability in thermal shock such as heat cycle.

Conventionally, a method for reducing the viscosity of a conductor paste has been to use large particles in order to reduce the amount of conductor filler or specific surface area, or to add a solvent having a low boiling point or a reactive diluent. .

[0005]

However, when the amount of the conductive filler added is reduced or large particles are used, the contact points between the fillers are reduced, the via hole connection resistance value is increased, and the heat of heat cycle or the like is increased. There was a problem that reliability could not be ensured in a test in which stress was generated.

Further, in the method of adding a solvent having a low boiling point or a reactive diluent, the weight loss due to volatilization of these components is large during curing of the hot press, and the volatile component causes swelling of the substrate, Alternatively, there is a problem that the adhesive strength with the wiring copper foil becomes weak.

Further, in a system without the addition of a dispersant,
In order to lower the viscosity, there was a problem that the particle shape was limited, and even with a relatively low viscosity, the viscosity increased and printing fillability into the via hole was difficult under a high share during printing. .

The present invention has been made in view of the above problems, and an object thereof is to obtain electrical connection between electrode layers by inner via hole connection, thermal shock resistance, low viscosity and low volatility. It is to obtain a conductor paste composition, and to obtain a double-sided printed board including an inner via hole connection using this paste to a multilayer printed board.

[0009]

In order to achieve the above object, the via-hole-filling conductor paste composition of the present invention comprises:
(A) 80 to 92% by weight of a conductor filler having an average particle size of 0.5 to 20 μm and a specific surface area of 0.1 to 1.5 m ² / g, (b) 2 or more at room temperature viscosity of 15 Pa · sec or less Of 8 to 20% by weight of liquid epoxy resin containing epoxy group and 0.5 to 5% by weight of (c) curing agent, the viscosity of which is 2,000 Pa · sec or less and the volatilization amount is 2 It is characterized in that it is 0.0% by weight or less.

In the above-mentioned constitution, a dispersant is further added in an amount of 0.01 to 1. with respect to 100 parts by weight of the compositions (a) to (c).
It is preferable to contain 5% by weight. Further, in the above structure, the conductor filler is preferably at least one fine particle selected from gold, silver, palladium, copper, nickel, tin, and lead. The range of the average particle size of the fine particles is 0.
It is preferably 5 to 20 μm.

In the above structure, the conductor filler is
Copper having a surface oxygen concentration of 1.0% by weight or less is preferable. In the above configuration, the epoxy resin is
At least one liquid epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, amine type epoxy resin, and glycidyl esterified epoxy resin is preferable.

Further, in the above constitution, it is preferable that the liquid epoxy resin contains 10 wt% or more of the epoxy resin obtained by converting dimer acid into glycidyl ester in the liquid epoxy resin.

In the above construction, the liquid epoxy resin is 50 wt% or less of at least one epoxy resin selected from bisphenol A and bisphenol F,
Epoxy equivalent of dimer acid converted to glycidyl ester 3
50% by weight of epoxy resin in the range of 00 to 600 g / eq
The above composition is preferable.

In the above construction, the curing agent is an amine-based curing agent such as dicyandiamide or carboxylic acid hydrazide, a urea-based curing agent such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea, or anhydrous phthalic acid. Acid, methyl nadic acid anhydride, pyromellitic anhydride, acid anhydride type curing agent such as hexahydrophthalic anhydride, diaminediphenylmethane, at least selected from aromatic amine type (amine adduct) curing agent such as diaminodiphenyl sulfonic acid It is preferably one curing agent.

Further, in the above constitution, it is preferable that the curing agent is a latent curing agent. Here, the latent curing agent is a mixture of an epoxy resin and a curing agent, which can be stored at room temperature without changing its properties for a long time and has a function of rapidly curing when heated to a predetermined temperature or higher. Say.

Further, in the above constitution, the dispersant is ethylene oxide of higher fatty acid, propylene oxide addition esterified product, ester compound of sorbitan and fatty acid, ethylene oxide of polyhydric alcohol such as sorbitan, propylene oxide addition ether compound, ethylene oxide of alkylbenzene, Nonionic dispersants such as propylene oxide adducts, alkylbenzene sulfonic acid alkali salts, higher alcohol sulfuric acid ester alkali salts, phosphate ester compounds, higher fatty acids, higher fatty acid ethylene oxide, anions such as propylene oxide adduct sulfate alkaline salts The dispersant is preferably at least one dispersant selected from quaternary ammonium salt type cationic dispersants.

Next, the double-sided printed circuit board of the present invention has an average particle size of 0.5 to 0.5 in the via hole opened in the insulating base material.
A conductive resin composition containing 80 to 92 wt% of a conductor filler having a specific surface area of 20 μm and a specific surface area of 0.1 to 1.5 m ² / g and 8 to 20 wt% of an epoxy ring-opened epoxy resin, and The upper and lower electrode layers on the surface of the insulating base material are electrically connected.

In the above construction, the insulating base material is preferably a composite material of aramid fiber and thermosetting resin. Further, in the above structure, the insulating base material is preferably a composite material of aramid nonwoven fabric and epoxy resin.

Next, the multilayer printed circuit board of the present invention has a plurality of insulating base layers and two or more electrode layers, and the via holes formed in each insulating base has an average particle size of 0. 5-
A conductive resin composition containing 80 to 92% by weight of a conductor filler having a specific surface area of 20 μm and a specific surface area of 0.1 to 1.5 m ² / g and 8 to 20% by weight of an epoxy ring-opened epoxy resin is filled. The structure is such that each electrode layer is electrically connected.

In the above structure, the insulating base material is preferably a composite material of aramid fiber and thermosetting resin. Further, in the above structure, the insulating base material is preferably a composite material of aramid nonwoven fabric and epoxy resin.

Next, according to the method for manufacturing a double-sided printed circuit board of the present invention, a via hole is previously formed in a prepreg used for manufacturing the printed circuit board, and the via hole is formed with (a).
The average particle size is 0.5 to 20 μm, and the specific surface area is 0.1.
80 to 92% by weight of a conductor filler of ~ 1.5 m ² / g,
(B) 8 to 20% by weight of a liquid epoxy resin containing two or more epoxy groups at room temperature viscosity of 15 Pa · sec or less,
(C) after filling with a conductor paste composition having a curing agent of 0.5 to 5% by weight and having a viscosity of 2,000 Pa · sec or less and a volatilization amount of 2.0% by weight or less A circuit is formed by sandwiching a copper foil between the upper and lower layers of the prepreg, applying heat and pressure, and etching the copper foil.

In the above structure, the prepreg is preferably a composite material of aramid fiber and thermosetting resin.
Further, in the above structure, the prepreg is preferably a sheet obtained by impregnating an aramid nonwoven fabric with a thermosetting epoxy resin.

Next, in the first method for manufacturing a multilayer printed circuit board according to the present invention, a via hole is previously formed in a prepreg used for manufacturing the printed circuit board, and (a) the average particle size is 0.5 to 20 μm. And a conductor filler having a specific surface area of 0.1 to 1.5 m ² / g 80 to 92
%, (B) 8 to 20% by weight of liquid epoxy resin containing 2 or more epoxy groups at room temperature viscosity of 15 Pa · sec or less, and (c) 0.5 to 5% by weight of a curing agent. After being filled with a conductive paste composition having a viscosity of 2,000 Pa · sec or less and a volatilization amount of 2.0 wt% or less, the conductive paste composition is placed on the upper and lower sides of a double-sided printed circuit board, and a copper foil is further provided on the outermost layer of the prepreg. A circuit is formed by heating and pressurizing the copper foil and then etching the copper foil.

In the above structure, the prepreg is preferably a composite material of aramid fiber and thermosetting resin.
Further, in the above structure, the prepreg is preferably a sheet obtained by impregnating an aramid nonwoven fabric with a thermosetting epoxy resin.

Next, in the second method for manufacturing a multilayer printed circuit board according to the present invention, a via hole is previously formed in a prepreg used for manufacturing the printed circuit board, and (a) the average particle size is 0.5 to 20 μm. And a conductor filler having a specific surface area of 0.1 to 1.5 m ² / g 80 to 92
%, (B) 8 to 20% by weight of liquid epoxy resin containing 2 or more epoxy groups at room temperature viscosity of 15 Pa · sec or less, and (c) 0.5 to 5% by weight of a curing agent. After filling with a conductor paste composition having a viscosity of 2,000 Pa · sec or less and a volatilization amount of 2.0 wt% or less, a double-sided printed circuit board is placed vertically and heated and pressed to form a circuit. Is characterized by.

In the above construction, the prepreg is preferably a composite material of aramid fiber and thermosetting resin.
Further, in the above structure, the prepreg is preferably a sheet obtained by impregnating an aramid nonwoven fabric with a thermosetting epoxy resin.

[0027]

According to the present invention described above, a one-liquid solvent-free conductor composition is obtained by dispersing a conductive filler having a specific performance in an epoxy resin having a specific property. By filling in, it is possible to obtain a double-sided printed circuit board and a multilayer printed circuit board having highly reliable via hole connection.

First, the conductor filler will be described. For the purpose of the present invention, the conductor filler needs to be contained in a high concentration in the conductor composition. The reason is that it is necessary to maintain the conduction reliability even when the resistance of the connecting via hole is lowered by increasing the contact probability between the conductor fillers and the substrate strain is applied by heat or mechanical stress as described above. is there.

In order to disperse the conductor filler in a high concentration, the smaller the specific surface area is, the better, even if the average particle diameter of the conductor filler is in the range of 0.2-20 μm. 5 m ² / g are suitable, more preferably is 0.1 to 1.0 M ² / g. Examples of the conductor filler include noble metals such as gold, silver, and palladium, and base metals such as copper, nickel, tin, and lead, but two or more kinds of them can be used in combination. As for the shape of the conductor filler, any one having the above-mentioned characteristics such as a spherical shape or a flake shape can be used.

In particular, it is desirable to use copper powder as the conductor filler from the viewpoint of suppressing migration, economical supply and cost stability. However, since the copper powder is generally easily oxidized, when used for filling the via hole for this purpose, the oxidation of the copper powder hinders the conductivity, so that the oxygen concentration of the copper powder is 1.0 wt% or less. Preferably there is.

Next, the epoxy resin having a specific property will be described. In order to form a solvent-free conductor composition with one liquid, a liquid resin is basically necessary as the epoxy resin. In order to disperse the above-mentioned conductor filler in a high concentration, the viscosity of the epoxy resin needs to be 15 Pa · sec or less. When an epoxy resin having a viscosity higher than that is used, the viscosity of the paste when the conductor composition is made into a paste is When the paste viscosity becomes 2,000 Pa · sec or more, the via hole filling operation cannot be performed.
The lower limit of the preferable viscosity of the epoxy resin is 0.2P.
On the other hand, when the composition is a or sec, when the composition is heated and compressed after being filled in a via hole, a volatile component is volatilized to generate a void in the structure filled with a via hole or peeling of a prepreg. It is necessary to control volatile matter so that there is no such matter. It is desirable that the volatilization amount be as small as possible, but if the content is 2.0% by weight or less, the above-mentioned problems do not occur.

Epoxy resins that can be used include liquid epoxy resins containing two or more epoxy groups such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin and amine type epoxy resin. Molecularly distilled liquid epoxy resins may also be used to reduce volatiles.

Among them, the epoxy resin obtained by converting dimer acid into glycidyl ester has a low viscosity (for example, 0.2 to 0.9).
(Pa · sec) at the same time, the cured product exhibits flexibility and has a large stress relaxation effect, so the reliability of the via-hole structure becomes high when it is mixed in an epoxy resin in an amount of 10 parts by weight or more.

In the above, the liquid epoxy resin is
50% by weight or less of at least one epoxy resin selected from bisphenol A and bisphenol F, and an epoxy equivalent of dimer acid converted to glycidyl ester of 300 to
According to the preferable example of the composition of 50% by weight or more of the epoxy resin in the range of 600 g / eq, the viscosity of the cured product is further low, the cured product exhibits flexibility, the stress relaxation effect is large, and the reliability of the via hole structure is high. Will be more likely.

As the curing agent, a general curing agent can be used. Amine type curing agents such as dicyandiamide and carboxylic acid hydrazide, urea type curing agents such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea, phthalic anhydride, methylnadic acid anhydride, pyromellitic anhydride,
An acid anhydride-based curing agent such as hexahydrophthalic anhydride and an aromatic amine-based (amine adduct) curing agent such as diaminodiphenylmethane and diaminodiphenylsulfonic acid are typically used. Among these, a solid latent curing agent is preferable from the viewpoint of stability and workability of the composition. Here, the solid latent curing agent is obtained by reacting several kinds of amine components with an epoxy resin to some extent to form resin particles, and encapsulating active groups such as amines in the three-dimensional structure of the polymer and blending with the epoxy resin. Then, part of the particle surface reacts, but the reaction stops here and it can be stored at room temperature without changing its properties for a long time, and when it is heated above a predetermined temperature, the particle melts or melts and is contained. An active group appears, the reaction is started all at once, and it has a function of rapidly curing.

As the dispersant, a generally used dispersant can be used. First, non-ionic compounds such as ethylene oxide of higher fatty acids, propylene oxide adducts, ester compounds of sorbitan and fatty acids, ethylene oxide of polyhydric alcohols such as sorbitan, propylene oxide adduct ether compounds, ethylene oxide of alkylbenzenes and propylene oxide adducts. Dispersant,
Secondly, alkylbenzene sulfonic acid alkali salt,
Higher alcohol sulfate ester alkali salt, phosphate ester compound, higher fatty acid, ethylene oxide of higher fatty acid, anionic dispersant such as sulfate alkali salt of propylene oxide adduct, and thirdly, quaternary ammonium salt type cationic dispersant. It is typically used.

The dispersant referred to herein is to reduce the viscosity of the paste by increasing the affinity between the surface of the metal particles in the paste and the organic resin blended as a binder.
It has the effect of adding fluidity to the metal particles when shear is added to the paste. Phenomenonally, the paste viscosity does not increase even under a high shear during screen printing, and the paste filling property into the via holes on the substrate is easily exhibited.

As the prepreg, almost any one can be used, such as glass epoxy, paper phenol, and aramid epoxy, as long as the thickness of the prepreg becomes smaller than that of the prepreg after curing.

According to the above-mentioned method of the present invention, a low-viscosity and low-volatility conductive paste composition for filling via holes, and a highly reliable double-sided printed circuit board and multi-layer printed circuit board which easily include inner via hole connections are provided. Can be formed. The inner via hole connection is a method of connecting both surfaces and each layer of the multilayer printed board at an arbitrary position.

[0040]

EXAMPLES Examples of a double-sided printed board using the conductor paste for filling via holes of the present invention, a method for forming the same, and a multilayer printed board using the same will be described in detail with reference to the drawings.

FIG. 1 is a structural sectional view of an embodiment of a double-sided printed circuit board according to the present invention. The double-sided printed circuit board 104 is composed of a laminated base material 101, a copper foil 102 (a copper foil of a wiring pattern in the figure), and a conductor via hole 103 in which a conductor paste is hardened. The point of the present invention is that the conductor paste composition is low in viscosity and easy to fill due to low volatility, and is a connection filled with a high content of the conductor filler, and is excellent in reliability as a substrate. Laminated substrate 101
For this, the currently known laminated base material can be used. For example, glass epoxy base material, aramid epoxy base material, paper phenol base material and the like can be used. Prior to heating and pressurization, it is called a prepreg, and the glass cloth or nonwoven fabric of the core material is impregnated with uncured resin.

As the conductive filler, most of the noble metals such as gold and silver or base metals such as copper, tin, nickel and lead can be used. Further, not only a pure metal but also an alloy, or a metal or insulating nucleus as shown in FIG. 5 covered with a conductive material can be used. In FIG. 5, 501 is a spherical nucleus, and 502 is a conductive material that covers the surface of the nucleus and serves as a conductive filler.

2A to 2D are process diagrams of the method for forming a double-sided substrate of the present invention. In FIG. 2, the laminated base material 201
Is a prepreg. A through hole is opened in this prepreg. Generally, a drill is often used, but it can be processed with a laser beam depending on the material. Figure 2 (b)
Shows a state in which FIG. 2A is sandwiched by the copper foil 202. FIG. 2C shows a state after applying heat and pressure to FIG. 2B. FIG. 2C shows a state in which the metal filling amount is increased in the through hole opened in the prepreg after heating and pressing. The prepreg is compressed and thinned,
Moreover, the resin is hardened. The conductor paste 203 is in a compressed state. The conductor 103 in this state plays a role of electrical connection between the upper and lower surfaces. FIG. 2D shows a state after processing (etching or the like) the surface copper foil 202 to form a wiring pattern. The processed copper foil 102 becomes a circuit conductor. A printed circuit board that can be put to practical use thereafter has steps such as applying a solder resist, printing letters and symbols, and making holes for insertion parts, but this step is not essential here, so it is omitted.

FIGS. 3 (a) and 3 (b) show a process of making a multilayer printed circuit board by repeatedly using the above-mentioned method for forming a double-sided printed circuit board. FIG. 3A shows a state in which the through-holes of FIG. 2A filled with the conductive paste are arranged on both sides (upper and lower surfaces) of the double-sided printed circuit board 104 which is the core, and the copper foil 202 is further placed. There is. In this state, by heating and pressing from the upper and lower surfaces, the multilayer printed board shown in FIG. 3B is obtained, and the inner via hole connection is already completed. Further, by processing the copper foils on the upper and lower surfaces into a pattern, a multilayer printed circuit board of four layers is completed. After that, this process can be repeated to make a multilayer printed circuit board having a larger number of layers.

In the method for forming a multilayer printed circuit board of FIG. 3, the double-sided printed circuit board of the present invention was used as the core double-sided printed circuit board, but it is not always necessary and it is easy to use a conventional through-hole double-sided printed circuit board. Recognize.
In this case, the through holes of the through holes should be filled in advance. Here, the through-hole substrate means a resin substrate. Not only through-hole boards but also ceramic boards can be used.

FIG. 4 shows another method for forming a multilayer printed board. In FIG. 4A, the conductor paste 20
The two-sided printed circuit board 104 sandwiches the prepreg 201 before heating and pressurizing which is filled with 3. By heating and pressing in this state, the four-layered multilayer printed board shown in FIG. 4B can be obtained. Not only 4 layers but also multiple double-sided printed circuit boards are prepared, and the laminated base material before heating and pressurizing filled with the above-mentioned conductive filler is sandwiched between the double-sided printed circuit boards and heated and pressed to obtain a multi-layered structure. A printed circuit board can be obtained.

In the method for forming a multilayer printed circuit board of FIG. 4, the double-sided printed circuit board of the present invention is used as the double-sided printed circuit board, but it is not always necessary and a conventional through-hole double-sided printed circuit board can be used. Not only through-hole boards but also ceramic boards can be used.

In the examples below, the contents of the epoxy resin are as follows. (1) Bisphenol A type epoxy resin (Epicoat 8
28 made of oiled shell epoxy, epoxy equivalent 184-1
94g / eq) (2) Bisphenol F type epoxy resin (Epicoat 8
07 Oiled shell epoxy, epoxy equivalent 160-1
75 g / eq) (3) Alicyclic epoxy resin (ST-1000 manufactured by Tohto Kasei, epoxy equivalent 200-220 g / eq) (4) Amine type epoxy resin (ELN-125 manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent 110-130 g / eq) eq) (5) Glycidyl esterified epoxy resin of dimer acid (epoxy equivalent 390 to 470 g / eq). In this example, it is also called a glycidyl ester-based epoxy resin. The structural formula is as shown below (Formula 1).

[0049]

[Chemical 1]

Example 1 In the first example of the present invention, as shown in FIG. 1, an aramid epoxy sheet having a thickness of 200 μm (TA-01 manufactured by Teijin Ltd.) was used as a prepreg.
A polyethylene terephthalate film having a thickness of 20 μm was attached to one surface of the prepreg using an adhesive, and a through hole having a diameter of 0.2 mm was formed in the base material using a drill.

85% by weight of silver, gold, copper, and nickel spherical and flake-shaped metal particles as a paste for filling a via hole in this through hole, and a bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy) as a resin composition. ) Epoxy resin obtained by converting 3% by weight of dimer acid into glycidyl ester (YD-171 manufactured by Tohto Kasei)
9% by weight and an amine adduct curing agent (M
Y-24 (manufactured by Ajinomoto Co., Inc.) 3% by weight was kneaded with a three-roll mill and charged. Table 1 shows the shape, average particle size and specific surface area of the metal particles and the viscosity of the paste for filling via holes at room temperature at 0.5 rpm with an E-type viscometer.

[0052]

[Table 1]

Add 35 to the prepreg filled with paste.
The copper foil 102 of μm is attached to the upper and lower surfaces of the prepreg,
Using a hot press, this is pressed at a temperature of 180 ° C. and a pressure of 50.
A double-sided copper clad plate was formed by heating and pressing at Kg / cm ² for 60 minutes.

When the paste viscosity is 2,000 Pa · sec or more, the workability of filling the via hole is difficult because of the high viscosity. An electrode pattern was formed on the double-sided copper clad plate formed by the above method by using a known etching technique.

Table 1 shows the connection resistance values of the inner via holes when the respective pastes were used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin. The specific resistance of each metal is silver (1.6 × 10 ⁻⁶ Ωcm) and gold (2.3 × 10 ⁻⁶ Ωc).
m), copper (1.7 × 10 ⁻⁶ Ωcm), nickel (6.8)
× 10 ⁻⁶ Ωcm).

(Embodiment 2) Similar to the first embodiment, the second embodiment
In the example, the average particle diameter of 2 μm as the metal particles of the conductive paste is applied to the prepreg in which the through holes having the diameter of 0.2 mm are formed.
85% by weight of copper powder of m, and 12% by weight of bisphenol A type epoxy resin (Epicoat 828 oiled shell epoxy), bisphenol F type epoxy resin (Epicoat 807 oiled shell epoxy), alicyclic epoxy as resin Resin (ST-1000 manufactured by Tohto Kasei), amine type epoxy resin (ELN-125 manufactured by Sumitomo Chemical Co., Ltd.),
Or an epoxy resin obtained by converting dimer acid into glycidyl ester) and an amine adduct curing agent (P
3% by weight of N-23 (manufactured by Ajinomoto Co., Inc.) was kneaded with a three-roll and filled. Table 2 shows the viscosity of the paste for filling via holes at room temperature and 300 ° C at a temperature rising rate of 10 ° C / min.
Shows the weight loss of the paste when heated up to, ie, the amount of volatilization. The volatilization amount was 2% by weight or less in any of the pastes, and no swelling was observed during the production of the substrate.

[0057]

[Table 2]

After filling this paste in a prepreg which has been subjected to perforation processing, copper foil 102 is stuck to the upper and lower surfaces of the prepreg, and this is pressed at a pressing temperature of 180 using a hot press.
A double-sided copper clad plate was formed by heating and pressurizing at 50 ° C. and a pressure of 50 kg / cm ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 2 shows the connection resistance value of the inner via hole when each paste is used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin.

Further, FIG. 6 shows a heat cycle test (-55
The change in via-hole resistance value up to 1000 cycles of 30 ° C. to 125 ° C. for 30 minutes each is shown. The change in the via hole resistance value of each paste sample is 10% or less with respect to the initial resistance value, and the reliability of the via hole is not impaired. In particular, in the glycidyl ester system, the rate of change was 1% or less, the change was small with respect to thermal shock due to the flexibility of the resin, and the via hole connection reliability was extremely good.

(Embodiment 3) In the third embodiment, similarly to the first embodiment, a prepreg having a through hole having a diameter of 0.2 mm has an average particle diameter of 2 μm as metal particles of a conductive paste.
85% by weight of copper powder of m, group A (bisphenol A type epoxy resin, bisphenol F type epoxy resin) and group B (alicyclic epoxy resin, amine type epoxy resin, or glycidyl esterified dimer acid) resin)
A total of 12% by weight of the above two kinds of resins blended with each other and 3% by weight of an amine adduct-based curing agent (MY-24) as a curing agent were kneaded with a three-roll mill to fill the mixture. Table 3 shows the viscosity of the paste for filling via holes, which was measured at a room temperature with an E-type viscometer at a rotation of 0.5 rpm.

[0062]

[Table 3]

A prepreg filled with this paste,
The copper foil 102 is attached to the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg /
A double-sided copper clad plate was formed by heating and pressing at 60 cm ² for 60 minutes, and an electrode pattern was formed by using a known etching technique.

Table 3 shows the connection resistance value of the inner via hole when each paste is used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin.

Further, FIG. 7 shows a heat cycle test (-55
The change in via-hole resistance value up to 1000 cycles of 30 ° C. to 125 ° C. for 30 minutes each is shown. The change in the via hole resistance value of each paste sample is 10% or less with respect to the initial resistance value, and the reliability of the via hole is not impaired. Particularly, in the system in which the glycidyl ester system is mixed, the change rate is 1% or less when the content is 50% by weight or more, and the via hole connection reliability is not impaired.

(Embodiment 4) In the fourth embodiment, as in the first embodiment, a prepreg having a through hole with a diameter of 0.2 mm has an average particle diameter of 2 μm as metal particles of a conductive paste.
75 to 92.5% by weight of silver powder or copper powder, and a total weight of 4.5, in which two kinds of resins are blended in a weight ratio of 25:75 of a bisphenol A type epoxy resin and an epoxy resin obtained by glucidyl esterification of timeric acid. -22% by weight and 3% by weight of an amine adduct curing agent (MY-24) as a curing agent were kneaded with a three-roll mill. Table 4 shows the viscosity of the paste for filling via holes at room temperature.

[0067]

[Table 4]

A prepreg filled with this paste,
The copper foil 102 is pasted on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 4 shows the connection resistance values of the inner via holes when the respective pastes were used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin. On the other hand, when the metal content is 80% by weight or less, the conductive metal is insufficient and the via hole resistance value is large. Further, when the metal content is 92% by weight or more, the paste viscosity becomes high and the via hole filling property becomes difficult.

(Embodiment 5) In the fifth embodiment, as in the first embodiment, a prepreg having a through hole with a diameter of 0.2 mm has an average particle diameter of 2 μm as metal particles of a conductive paste.
85% by weight of silver powder or copper powder of m, and bisphenol A
Type epoxy resin and dimer acid glycidyl esterified epoxy resin weight ratio of 25:75, a total amount of 12% by weight of two kinds of resin blended, and 3% by weight as a curing agent
Dicyandiamide (manufactured by DICY7 oily shell epoxy), or acid anhydride (manufactured by RIKACID MH Shin Nihon Rika), amine adduct curing agent (PN-23, MY-24)
(Made by Ajinomoto Co., Inc.) was kneaded with three rolls and filled. Table 5
Shows the viscosity of the paste for filling via holes at room temperature and the volatilization amount of the paste when heated to 300 ° C. at a heating rate of 10 ° C./min.

[0071]

[Table 5]

The prepreg filled with the paste is pasted with the copper foil 102 on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 5 shows the connection resistance values of the inner via holes when the respective pastes were used. Regardless of the type of curing agent, the specific resistance value is 1 of the specific resistance value of the conductor even if it contains an insulating resin regardless of which paste is used.
A low resistance connection, which is 0 times or less, was obtained.

(Embodiment 6) In the sixth embodiment, similarly to the first embodiment, a prepreg having a through hole with a diameter of 0.2 mm has an average particle diameter of 2 μm as metal particles of a conductive paste.
85% by weight of copper powder of m, the weight ratio of the bisphenol A type epoxy resin and the glycidyl esterified epoxy resin is 25:75, and the total amount of the two resins is 8 to 1
4.5% by weight and 0.5 to 7% by weight of phthalic anhydride as a curing agent, or amine adduct type curing agent (MY-2
4) was kneaded with a triple roll and filled. Table 6 shows the viscosity of the paste for filling via holes at room temperature and the heating rate 1
The volatilization amount of the paste when heated to 300 ° C. at 0 ° C./minute is shown.

[0075]

[Table 6]

The prepreg filled with the paste is laminated with the copper foil 102 on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 6 shows the connection resistance values of the inner via holes when the respective pastes were used. Regardless of the weight ratio of the curing agent, a low resistance connection in which the specific resistance value was not more than 10 times the specific resistance value of the conductor was obtained even though the insulating resin was included, regardless of which paste was used. However, in the case of solid powder such as amine adduct curing agent, the paste viscosity increases as the addition amount increases, and it is difficult to fill via holes with the addition paste containing more than 5% by weight of the curing agent, and volatilization such as acid anhydride occurs. If the amount of volatilization exceeds 2% by weight, a satisfactory double-sided copper clad plate cannot be obtained due to the swelling of the substrate and the electrode.

(Embodiment 7) In the seventh embodiment, similarly to the first embodiment, a prepreg having a through hole with a diameter of 0.2 mm is formed, and the average particle having different surface oxygen concentration is used as the metal particle of the conductive paste. 85% by weight of copper powder having a diameter of 2 μm, 12% by weight of a total of 12% by weight of a bisphenol A type epoxy resin and a glycidyl esterified epoxy resin blended with 25:75, and 3% by weight as a curing agent. % Of the amine adduct curing agent (MY-24) was kneaded with a three-roll and filled. Table 7 shows the viscosity of the paste for filling via holes at room temperature.

[0079]

[Table 7]

The prepreg filled with the paste is laminated with the copper foil 102 on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 7 shows the connection resistance value of the inner via hole when each paste is used. With a paste having a surface oxygen concentration of copper of 1.0% by weight or less, the specific resistance value is 10% of the specific resistance value of the conductor even though it contains an insulating resin.
A low resistance connection that is less than double is obtained. However, as the surface oxygen concentration increases, the in-via hole connection resistance increases, and when the amount exceeds 1.0% by weight, the resistance value rapidly increases and a low resistance connection, which is less than 10 times the specific resistance value of the conductor, is established. I can't get it.

Example 8 85% by weight of copper powder having an average particle size of 2 μm was used as the metal particles of the conductive paste, and the ratio of the bisphenol A type epoxy resin to the glycidyl esterified epoxy resin was set to 25:75. A total of 12% by weight of the resin blended with 3% by weight of an amine adduct curing agent (MY-24) as a curing agent was kneaded with a three-roll mill to form a pattern for measuring connection resistance. An aramid-epoxy prepreg in which the above paste is filled in a prepreg having a through hole with a diameter of 0.2 mm is sandwiched between two aramid / epoxy double-sided substrates, and the temperature is 180 ° C. using a hot press. A 4-layer printed circuit board was formed by heating and pressurizing at a pressure of 50 kg / cm ² for 60 minutes.

The connection resistance of the inner via hole formed between the second and third layers of the four-layer substrate showed the same resistance value as in Example 1. Similarly, also in the 6-layer printed circuit board, similar reliability was obtained with the same connection resistance value as the 4 layers.

Further, an aramid-epoxy double-sided board 1 produced by the same method as in Example 1 using the above paste.
On both sides of the sheet, two aramid-epoxy prepregs in which the above paste was filled in a prepreg having a through hole with a diameter of 0.2 mm were sandwiched, and this was pressed using a hot press at a press temperature of 180 ° C. and a pressure of 50 kg / cm. ^Even in the method of forming a 4-layer printed circuit board by heating and pressurizing at ² for 60 minutes,
An equivalent via hole connection resistance was obtained. Further, similar reliability was obtained also in a 6-layer printed circuit board manufactured by using this method.

Similar reliability of via-hole connection resistance was obtained by using a circuit-formed ceramic substrate instead of the aramid-epoxy double-sided substrate produced by the same method as in Example 1.

(Embodiment 9) In a ninth embodiment of the present invention, as shown in FIG. 1, an aramid epoxy sheet (TA-01 manufactured by Teijin Ltd.) having a thickness of 200 μm as a prepreg.
A polyethylene terephthalate film having a thickness of 20 μm was attached to one surface of the prepreg using an adhesive, and a through hole having a diameter of 0.2 mm was formed in the base material using a drill.

As a paste for filling a via hole in this through hole, 85 wt% of silver, gold, copper, nickel spherical and flake-shaped metal particles, and a resin composition of bisphenol A type epoxy resin (Epicoat 828 oil-made shell epoxy ) Epoxy resin obtained by converting 3% by weight of dimer acid into glycidyl ester (YD-171 manufactured by Tohto Kasei)
9% by weight, amine adduct curing agent (MY-
24 Ajinomoto) 3% by weight and 0.01 to 2.0% by weight relative to the total weight of metal, resin and curing agent as a dispersant, polyoxyethylene sorbitan fatty acid ester (nonionic surfactant "Sorgen" TW No. Ichigo Pharmaceutical Co., Ltd., phosphoric acid ester (anionic surfactant "Prysurf")
(Daiichi Kogyo Seiyaku Co., Ltd.) and a cationic surfactant "Cathiogen" (Daiichi Kogyo Seiyaku Co., Ltd.) were kneaded with a three-roll mill and filled. Table 8 shows the shape of metal particles, average particle diameter, specific surface area, kind and amount of dispersant (% by weight), and 0.5 r of the via hole filling paste at room temperature with an E-type viscometer.
The viscosity at pm is shown.

[0088]

[Table 8]

The prepreg filled with the paste, 35
The copper foil 102 of μm is attached to the upper and lower surfaces of the prepreg,
Using a hot press, this is pressed at a temperature of 180 ° C. and a pressure of 50.
A double-sided copper clad plate was formed by heating and pressing at 60 kg / cm ² for 60 minutes.

When the paste viscosity is out of the scope of the claims of the present invention and the paste viscosity is 2,000 Pa · sec or more, the workability of filling the via hole is difficult because of the high viscosity. An electrode pattern was formed on the double-sided copper clad plate formed by the above method by using a known etching technique.

Table 8 shows the connection resistance values of the inner via holes when the respective pastes were used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin. The specific resistance values of the metals used in the examples are silver (1.6 × 10 ⁻⁶ Ωcm) and gold (2.
3 × 10 ⁻⁶ Ωcm), copper (1.7 × 10 ⁻⁶ Ωcm), and nickel (6.8 × 10 ⁻⁶ Ωcm).

FIG. 8 shows a change in paste viscosity when shearing is applied to the paste by changing the number of revolutions with an E-type viscometer. As the paste, a paste whose viscosity decreases under high shear during printing as compared with the state without shear is desirable as the filling property of the paste. Those that do not add a dispersant,
When the shear is applied, the viscosity increases, making it difficult to fill the paste. On the other hand, when the dispersant is added, the viscosity does not increase at a high share, and when the amount added exceeds 0.5 part by weight, the viscosity decreases at a high share, and the filling becomes easy. However, when the amount of the dispersant added was 2.0% by weight or more, the connection of metal particles was hindered and the via connection resistance increased.

(Embodiment 10) Similar to the ninth embodiment, in the tenth embodiment, a copper powder having an average particle diameter of 2 μm is used as a metal particle of a conductive paste in a prepreg having a through hole having a diameter of 0.2 mm. Of 85% by weight and 12% by weight of bisphenol A type epoxy resin, bisphenol F type epoxy resin (Epicote 807 made by Yuka Shell Epoxy), alicyclic epoxy resin (ST-1000 manufactured by Toto Kasei), amine type epoxy Resin (ELN-125 manufactured by Sumitomo Chemical Co., Ltd.) or epoxy resin obtained by glucidyl esterification of dimer acid, 3% by weight of amine adduct curing agent (PN-23 manufactured by Ajinomoto Co., Inc.) as a curing agent, and metal, resin, curing as a dispersant. 0.2% by weight based on the total weight of the agent
Of the phosphoric acid ester (produced by PRYSURF Daiichi Kogyo Seiyaku Co., Ltd.) was kneaded with a triple roll and filled. Table 9 shows the viscosity of the paste for filling via holes at room temperature and the heating rate 1
The weight loss of the paste, ie, the amount of volatilization, when heated to 300 ° C. at 0 ° C./minute is shown. The volatilization amount was 2% by weight or less in any of the pastes, and no swelling was found during the production of the substrate.

[0094]

[Table 9]

After filling this paste in a prepreg that has been subjected to perforation processing, copper foil 102 is attached to the upper and lower surfaces of the prepreg and this is pressed at a pressing temperature of 180 using a hot press.
A double-sided copper clad plate was formed by heating and pressurizing at 50 ° C. and a pressure of 50 kg / cm ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 9 shows the connection resistance values of the inner via holes when the respective pastes were used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin.

(Embodiment 11) In the eleventh embodiment, the eighth
In the same manner as in the above example, 85% by weight of copper powder having an average particle size of 2 μm as metal particles of the conductive paste was added to a prepreg having a through hole with a diameter of 0.2 mm.
Type epoxy resin, bisphenol F type epoxy resin) and Group B (alicyclic epoxy resin, amine type epoxy resin, or epoxy resin obtained by glucidyl esterification of dimer acid), and the total amount is 12% by weight. ,
Amine adduct type curing agent (MY-24) 3 as a curing agent
As a weight% and as a dispersant, 0.2 wt% of a phosphoric acid ester (manufactured by PRYSURF Daiichi Kogyo Seiyaku Co., Ltd.) with respect to the total weight of the metal, the resin and the curing agent was kneaded by a three-roll mill and filled. Table 10 shows the viscosity of the paste for filling via holes at room temperature when measured with an E-type viscometer at 0.5 RPS.

[0098]

[Table 10]

A prepreg filled with this paste,
The copper foil 102 is pasted on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 10 shows the connection resistance values of the inner via holes when the respective pastes were used. With any of the pastes, it was possible to obtain a low resistance connection in which the specific resistance value was 10 times or less of the specific resistance value of the conductor even though it contained an insulating resin.

(Embodiment 12) In the twelfth embodiment, the eighth embodiment
In the same manner as in the above example, a prepreg having a through hole with a diameter of 0.2 mm was formed.
75 to 92.5% by weight of silver powder or copper powder of μm, and the weight ratio of the bisphenol A type epoxy resin and the epoxy resin obtained by converting dimer acid into glycidyl ester is 25:75.
4.5 to 22% by weight of a total of 4.5 to 22 kinds of resins blended,
3% by weight of an amine adduct curing agent (MY-24) as a curing agent and 0.2% by weight of a phosphoric acid ester (Prysurf Daiichi Kogyo Seiyaku Co., Ltd.) based on the total weight of metal, resin and curing agent as a dispersant. Was kneaded with three rolls. Table 11
Shows the viscosity of the via hole filling paste at room temperature.

[0102]

[Table 11]

A prepreg filled with this paste,
The copper foil 102 is pasted on the upper and lower surfaces of the prepreg, and this is heat-pressed at a press temperature of 180 ° C and a pressure of 50 kg / cm
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 11 shows the connection resistance values of the inner via holes when the respective pastes were used. Any of the pastes can be used to obtain a low resistance connection in which the specific resistance value is 10 times or less of the specific resistance value of the conductor even though the insulating resin is included, but the composition outside the scope of the claims of the present invention is obtained. When the metal content is 80% by weight or less, the conductor metal is insufficient and the via hole resistance value is large. The metal content is 9
When it is 2.5% by weight or more, the paste viscosity becomes high and the via hole filling property becomes difficult.

(Embodiment 13) In the thirteenth embodiment, the eighth embodiment
In the same manner as in Example 1, 85 wt% of silver powder or copper powder having an average particle size of 2 μm as metal particles of the conductive paste, bisphenol A type epoxy resin and dimer acid were added to a prepreg having a through hole with a diameter of 0.2 mm. The total weight of the glycidyl esterified epoxy resin is 25:75, and the total amount is 12% by weight, and 3% by weight of dicyandiamide (made by DICY7 oil shell epoxy) or acid anhydride ( RIKACID MH, manufactured by Shin Nippon Rika Co., Ltd., amine adduct curing agent (PN-23, MY-24)
Ajinomoto) and as a dispersant, a metal, resin, 0.2% by weight phosphoric acid ester (Prysurf Daiichi Kogyo Seiyaku Co., Ltd.) based on the total weight of the curing agent is kneaded with a triple roll,
Filled. Table 12 shows the viscosity of the via hole filling paste at room temperature (25 ° C.) and the viscosity at a temperature rising rate of 10 ° C./min.
The volatile amount of the paste when heated to 0 ° C is shown.

[0106]

[Table 12]

The copper foil 102 was adhered to the upper and lower surfaces of the prepreg with the paste-filled prepreg, and this was pressed using a hot press at a pressing temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 12 shows the connection resistance values of the inner via holes when the respective pastes were used. Regardless of the type of curing agent, the specific resistance value is 1 of the specific resistance value of the conductor even if it contains an insulating resin regardless of which paste is used.
A low resistance connection, which is 0 times or less, was obtained.

(Embodiment 14) In the fourteenth embodiment, the eighth
In the same manner as in the above Example, 85 wt% of copper powder having an average particle size of 2 μm as metal particles of the conductive paste, bisphenol A type epoxy resin and dimer acid were glucidyl in a prepreg having a through hole with a diameter of 0.2 mm. The total weight of the esterified epoxy resin was 25 to 75, and the total amount was 8 to 14.5% by blending two kinds of resins.
5 to 7% by weight of phthalic anhydride or amine adduct type curing agent (MY-24) and, as a dispersant, 0.2% by weight of phosphoric acid ester (plysurf) based on the total weight of metal, resin and curing agent. (Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was kneaded with three rolls and filled. Table 13 shows the viscosity of the paste for filling via holes at room temperature and the temperature rise rate of 10 ° C./min.
The volatile amount of the paste when heated to ℃ is shown.

[0110]

[Table 13]

The copper foil 102 was pasted on the upper and lower surfaces of the prepreg filled with the paste, and the prepreg was heat-pressed at a pressing temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 13 shows the connection resistance values of the inner via holes when the respective pastes were used. Regardless of the weight ratio of the curing agent, a low resistance connection in which the specific resistance value was not more than 10 times the specific resistance value of the conductor was obtained even though the insulating resin was included, regardless of which paste was used. However, in the case of solid powder such as amine adduct curing agent, the paste viscosity increases as the addition amount increases, and it is difficult to fill via holes with the addition paste containing more than 5% by weight of the curing agent, and volatilization such as acid anhydride occurs. If the amount of volatilization exceeds 2% by weight, a satisfactory double-sided copper clad plate cannot be obtained due to the swelling of the substrate and the electrode.

(Embodiment 15) In the fifteenth embodiment, the eighth embodiment
In the same manner as in the above Example, 85 wt% of copper powder having an average particle diameter of 2 μm having different surface oxygen concentrations as metal particles of a conductive paste was added to a prepreg having a through hole having a diameter of 0.2 mm, and a bisphenol A type epoxy resin. The ratio of glycidyl esterified dimer acid epoxy resin is 25:75 to 2
A total of 12% by weight of various kinds of resins blended, 3% by weight of amine adduct curing agent (MY-24) as a curing agent and 0.2% by weight with respect to the total weight of metal, resin and curing agent as a dispersant. Of the phosphoric acid ester (produced by PRYSURF Daiichi Kogyo Seiyaku Co., Ltd.) was kneaded with a triple roll and filled. Table 14 shows the viscosity of the paste for filling via holes at room temperature.

[0114]

[Table 14]

The copper foil 102 was attached to the upper and lower surfaces of the prepreg with the paste-filled prepreg, and this was pressed using a hot press at a pressing temperature of 180 ° C. and a pressure of 50 kg / cm.
^A double-sided copper clad plate was formed by heating and pressurizing at ² for 60 minutes, and an electrode pattern was formed using a known etching technique.

Table 14 shows the connection resistance values of the inner via holes when the respective pastes were used. With a paste having a surface oxygen concentration of copper of 1.0% by weight or less, the specific resistance value is 10% of the specific resistance value of the conductor even though it contains an insulating resin.
A low resistance connection that is less than double is obtained. However, as the surface oxygen concentration increases, the in-via hole connection resistance increases, and when the amount exceeds 1.0% by weight, the resistance value rapidly increases and a low resistance connection, which is less than 10 times the specific resistance value of the conductor, is established. I can't get it.

Example 16 85% by weight of copper powder having an average particle size of 2 μm was used as the metal particles of the conductive paste, and the ratio of the bisphenol A type epoxy resin and the epoxy resin obtained by glucidyl esterification of dimer acid was adjusted to 25:75. A total of 12% by weight of two kinds of resins blended, 3% by weight of an amine adduct curing agent (MY-24) as a curing agent and 0.2% by weight with respect to the total weight of metal, resin and curing agent as a dispersant. % Phosphoric acid ester (Prysurf Daiichi Kogyo Seiyaku Co., Ltd.)
Was kneaded with a three-roll mill, and the above paste was applied to a diameter of 0.2 between two aramid / epoxy double-sided boards on which a pattern for measuring the connection resistance was formed.
A aramid-epoxy prepreg filled in a prepreg having mm through holes is sandwiched, and this is heated and pressed at a press temperature of 180 ° C. and a pressure of 50 kg / cm ² for 60 minutes using a hot press to form a four-layer printed board. .

The connection resistance of the inner via hole formed between the second and third layers of the four-layer substrate showed the same resistance value as in Example 1. Similarly, also in the 6-layer printed circuit board, similar reliability was obtained with the same connection resistance value as the 4 layers.

Further, an aramid-epoxy double-sided board 1 produced by the same method as in Example 8 using the above paste.
On both sides of the sheet, two aramid-epoxy prepregs in which the above paste was filled in a prepreg having a through hole with a diameter of 0.2 mm were sandwiched, and this was pressed using a hot press at a press temperature of 180 ° C. and a pressure of 50 kg / cm. ^Even in the method of forming a 4-layer printed circuit board by heating and pressurizing at ² for 60 minutes,
An equivalent via hole connection resistance was obtained. Further, similar reliability was obtained also in a 6-layer printed circuit board manufactured by using this method.

Similar reliability of via-hole connection resistance was obtained by using a circuit-formed ceramic substrate instead of the aramid-epoxy double-sided substrate produced by the same method as in Example 8.

[0121]

As described above, according to the double-sided printed circuit board using the paste for filling via holes of the present invention, the method for forming the same, and the multilayer board using the same, it is possible to simply and easily use an inner layer without using a through-hole plating technique.・ A double-sided printed circuit board with via holes can be realized, and its multilayer structure can be easily realized.

[Brief description of drawings]

FIG. 1 is a structural cross-sectional view showing a double-sided printed circuit board according to an embodiment of the present invention.

FIG. 2 is a process diagram of a method for forming a double-sided printed circuit board in the example.

FIG. 3 is a process diagram of a method for forming a multilayer printed circuit board according to the same embodiment.

FIG. 4 is a process diagram of another method for forming a multilayer printed board according to the embodiment.

FIG. 5 is a structural diagram of conductive particles used for the printed circuit board in the example.

FIG. 6 is a diagram showing a relationship between a change in a via hole connection resistance value produced by a paste containing each epoxy resin on a printed circuit board in the same example in a heat cycle test and the number of tests.

FIG. 7 is a diagram showing a relationship between a change in a via-hole connection resistance value and a number of times of tests in a heat cycle test, which are prepared by using a paste containing an epoxy resin having a different composition in the printed circuit board in the example.

FIG. 8 is a diagram showing a relationship between a rotational speed (share) and a viscosity of an E-type viscometer of a dispersant and a paste having a different addition amount in the same example.

[Explanation of symbols]

 101 laminated base material 102 copper foil after processing 103 conductive particles 104 double-sided printed circuit board 201 laminated base material before heating and pressurization 202 copper foil 203 conductive particles 501 nucleus 502 conductive material

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08J 5/04 CFC 7310-4F 5/24 CFC 7310-4F C08K 3/08 C08L 63/00 NKU C09D 5/34 PRC H01B 1/00 H 7244-5G H05K 1/03 D 7011-4E 1/11 N 7511-4E 3/40 K 7511-4E 3/46 N 6921-4E S 6921-4E T 6921-4E ( 72) Inventor Seiichi Nakatani 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Tatsuo Ogawa, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Suehiro Gauri Kyoto Prefecture 50-8 Kawashima Kurita-cho, Nishikyo-ku, Kyoto (72) Inventor Koichi Kousaku 48-29 Nishiyama, Ogura-machi, Uji-shi, Kyoto (72) Hideo Akiyama 4-8 Fukakusa-Nishiura-cho, Fushimi-ku, Kyoto-shi, Kyoto 1 Maison Fukakusa No. 210

Claims (35)

[Claims] 1. A conductive filler 8 having an average particle size of 0.5 to 20 μm and a specific surface area of 0.1 to 1.5 m ² / g.
0 to 92% by weight, (b) 4.5 to 20% by weight of liquid epoxy resin containing 2 or more epoxy groups at room temperature viscosity of 15 Pa · sec or less, and (c) 0.5 to 5% by weight of curing agent. A composition having a viscosity of 2,000 Pa · s
A conductor paste composition for filling via holes, which has an ec or less and a volatilization amount of 2.0 wt% or less. 2. The via-hole-filling conductor paste composition according to claim 1, further comprising 0.01 to 1.5% by weight of a dispersant based on 100 parts by weight of the compositions (a) to (c). . 3. The conductor filler is gold, silver, palladium,
The conductor paste composition for filling via holes according to claim 1, which is at least one fine particle selected from copper, nickel, tin, and lead. 4. The conductor filler has a surface oxygen concentration of 1.
The via-hole-filling conductor paste composition according to claim 1 or 2, which comprises 0% by weight or less of copper. 5. The epoxy resin is at least one liquid epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, amine type epoxy resin and glycidyl esterified epoxy resin. The conductor paste composition for filling via holes according to 1. 6. The conductor paste composition for filling via holes according to claim 1, wherein the liquid epoxy resin contains 10% by weight or more of an epoxy resin obtained by converting dimer acid into glycidyl ester. 7. A liquid epoxy resin comprising 50% by weight or less of at least one epoxy resin selected from bisphenol A and bisphenol F, and 50% by weight of epoxy resin obtained by converting dimer acid into glycidyl ester in an epoxy equivalent of 300 to 600 g / eq. % Or more composition, The conductor paste composition for filling via holes according to claim 1 or 2. 8. The curing agent is at least one curing agent selected from amine-based curing agents, urea-based curing agents, acid anhydride-based curing agents, and aromatic amine-based (amine adduct) curing agents. The conductor paste composition for filling via holes according to [4]. 9. The conductor paste composition for filling via holes according to claim 1, wherein the curing agent is a latent curing agent. 10. The conductor paste composition for filling via holes according to claim 1, wherein the dispersant is at least one dispersant selected from a nonionic dispersant, an anionic dispersant, and a cationic dispersant. 11. A conductor filler having an average particle diameter of 0.5 to 20 μm and a specific surface area of 0.1 to 1.5 m ² / g in a via hole opened in an insulating base material in an amount of 80 to 92% by weight. And a conductive resin composition containing 4.5 to 20% by weight of epoxy ring-opened epoxy resin, and the upper and lower electrode layers on the surface of the insulating base material are electrically connected. 12. The double-sided printed circuit board according to claim 11, wherein the insulating base material is a composite material of aramid fiber and thermosetting resin. 13. The double-sided printed circuit board according to claim 11, wherein the insulating base material is a composite material of aramid nonwoven fabric and epoxy resin. 14. A via hole having a plurality of insulating base material layers and two or more electrode layers, and having an average particle diameter of 0.5 to 20 μm in a via hole opened in each insulating base material and having a specific surface area. Is filled with a conductive resin composition containing 80 to 92% by weight of a conductor filler of 0.1 to 1.5 m ² / g and 4.5 to ²⁰ % by weight of an epoxy ring-opened epoxy resin. Multi-layer printed circuit board with electrically connected structure. 15. The multilayer printed circuit board according to claim 14, wherein the insulating base material is a composite material of aramid fiber and thermosetting resin. 16. The multilayer printed board according to claim 14, wherein the insulating base material is a composite material of aramid nonwoven fabric and epoxy resin. 17. A prepreg used for manufacturing a printed circuit board is preliminarily formed with a via hole, and (a) the average particle size is 0.5 to 20 μm and the specific surface area is 0.1 to 1.5 m ^{2 in the} via hole. / G conductor filler 80-92
% By weight, (b) 4.5 to 2 liquid epoxy resin containing 2 or more epoxy groups at room temperature viscosity of 15 Pa · sec or less
A conductor paste composition having a viscosity of 2,000 Pa · sec or less and a volatilization amount of 2.0 wt% or less, which is a composition comprising 0 wt% and (c) a curing agent of 0.5 to 5 wt%. After filling with, the copper foil is sandwiched between the upper and lower layers of the prepreg, heated and pressed, and the circuit is formed by etching the copper foil to form a circuit. 18. The method for producing a double-sided printed circuit board according to claim 17, wherein the prepreg is a composite material of aramid fiber and thermosetting resin. 19. The method for producing a double-sided printed circuit board according to claim 17, wherein the prepreg is a sheet obtained by impregnating an aramid nonwoven fabric with a thermosetting epoxy resin. 20. The method for producing a double-sided printed circuit board according to claim 17, further comprising 0.01 to 1.5% by weight of a dispersant with respect to 100 parts by weight of the compositions (a) to (c). 21. The conductor filler is gold, silver, palladium,
The method for producing a double-sided printed circuit board according to claim 17, wherein the fine particle is at least one fine particle selected from copper, nickel, tin, and lead. 22. The method for producing a double-sided printed circuit board according to claim 17, wherein the conductor filler is copper having a surface oxygen concentration of 1.0% by weight or less. 23. The epoxy resin is at least one liquid epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, amine type epoxy resin and glycidyl esterified epoxy resin. 17. The method for manufacturing a double-sided printed circuit board according to item 17. 24. The method for producing a double-sided printed board according to claim 17, wherein the liquid epoxy resin contains 10% by weight or more of an epoxy resin obtained by converting dimer acid into glycidyl ester. 25. The liquid epoxy resin is bisphenol A.
And 50% by weight or less of at least one epoxy resin selected from bisphenol F and 50% by weight or more of an epoxy resin obtained by converting glycidyl ester of dimer acid into an epoxy equivalent of 300 to 600 g / eq. A method for manufacturing the double-sided printed circuit board described. 26. The curing agent is at least one curing agent selected from amine-based curing agents, urea-based curing agents, acid anhydride-based curing agents, and aromatic amine-based (amine adduct) curing agents. A method for manufacturing a double-sided printed circuit board according to. 27. A via hole is previously formed in a prepreg used for manufacturing a printed circuit board, and (a) the average particle size is 0.5 to 20 μm and the specific surface area is 0.1 to 1.5 m ² / g conductor filler 80-92
% By weight, (b) 4.5 to 2 liquid epoxy resin containing 2 or more epoxy groups at room temperature viscosity of 15 Pa · sec or less
A composition comprising 0% by weight and (c) 0.5 to 5% by weight of a curing agent, the viscosity of which is (d) 2,000 Pa · sec.
After filling with a conductor paste composition having the following content and a volatilization amount of 2.0% by weight or less, (e) the conductive paste composition is placed on the upper and lower sides of a double-sided printed circuit board, and a copper foil is sandwiched between the outermost layers of the prepreg and heated and pressed. After that, the copper foil is etched, or the double-sided printed boards are arranged one above the other, and heated and pressed to form a circuit. 28. The method for producing a multilayer printed circuit board according to claim 27, wherein the prepreg is a composite material of aramid fiber and a thermosetting resin. 29. The method for producing a multilayer printed circuit board according to claim 27, wherein the prepreg is a sheet obtained by impregnating an aramid nonwoven fabric with a thermosetting epoxy resin. 30. The method for producing a multilayer printed circuit board according to claim 27, further comprising 0.01 to 1.5% by weight of a dispersant based on 100 parts by weight of the compositions (a) to (c). 31. The conductor filler is gold, silver, palladium,
The method for producing a multilayer printed board according to claim 27, wherein the fine particles are at least one fine particle selected from copper, nickel, tin, and lead. 32. The method for producing a multilayer printed board according to claim 27, wherein the conductor filler is copper having a surface oxygen concentration of 1.0% by weight or less. 33. The epoxy resin is at least one liquid epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, amine type epoxy resin and glycidyl esterified epoxy resin. 27. The method for manufacturing a multilayer printed board according to 27. 34. The method for producing a multilayer printed board according to claim 27, wherein the liquid epoxy resin contains 10% by weight or more of an epoxy resin obtained by converting dimer acid into glycidyl ester. 35. The liquid epoxy resin is bisphenol A.
28. A composition comprising 50% by weight or less of at least one epoxy resin selected from bisphenol F and 50% by weight or more of an epoxy resin having a glycidyl ester of dimer acid and having an epoxy equivalent of 300 to 600 g / eq. For manufacturing a multilayer printed circuit board.