JP2003092024A - Via hole filling conductive paste, and circuit board using the same, and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive paste hardly causing concavity when filled, and to provide a circuit board with high reliability of which, the conductive paste is effectively compressed by filling the above conductive paste in a via hole. SOLUTION: The via hole filling conductive paste component is composed by dispersing a plural kinds of conductive particles having different mean diameter from each other within a range of 0.5-20 μm in liquid epoxy resin. For an intermediate body ID (a), in the case of using a single conductive powder with uniform mean diameter, it is possible that the conductive powder E forms a concavity when the conductive paste is filled as shown in the figure (b), and causes a defective conductivity, however, the concavity is eliminated and the conductive powder is filled up to the height of a mold releasing film 100 by using above conductive paste.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paste for filling via holes, a circuit board using the same, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and high density of electronic equipment, there has been an increasing demand for circuit boards suitable for miniaturization and high density not only in industrial fields but also in a wide range of consumer fields. As an example of a circuit board that has been created in response to such a demand, there is an all-layer IVH resin multilayer circuit board in which interlayer connection is performed through interstitial via holes (hereinafter abbreviated as IVH) (Patent No. 2601128).

This circuit board has a structure in which the wiring patterns deposited on the surface of each of a plurality of insulating materials are electrically connected by contact with the conductive powder filled in the through holes of the insulating material. Has become. When manufacturing such a circuit board, through holes are formed in an insulating material having compressibility, and a resin composition containing conductive powder is filled in the through holes of the insulating material with a squeegee or the like, The copper foil is laminated on the surface of the insulating material, and the insulating material and the copper foil are heated while being compressed in the thickness direction. Further, subsequently, the wiring pattern is formed by etching the copper foil which is pressed and heated to adhere to the surface of the insulating material.

[0004]

In order to further reduce the size and the density of the circuit board as described above, the diameter of the via hole is inevitably reduced. Against this background, as one means for manufacturing a circuit board having high reliability, increasing the filling amount of the conductive powder in the via hole can be mentioned. Specifically, a measure such as making the conductive powder with a small particle size filled in the via hole is taken. However, if an attempt is made to fill the via hole with a conductive powder having a small particle diameter by using a squeegee or the like, the conductive powder is easily taken by the squeegee and a dent occurs in filling the via hole. Therefore, the compressibility of the conductive paste in the via hole is reduced by the amount of the recess of the conductive paste, which makes it very difficult to manufacture a circuit board having high reliability.

The present invention was devised in view of such inconveniences, and an object thereof is to provide a conductive paste that is unlikely to cause dents during filling. Further, it is an object of the present invention to provide a circuit board having high reliability because the conductive paste in the via hole is more efficiently compressed by filling the conductive paste in the via hole.

[0006]

In order to achieve the above object, the conductive paste composition for filling via holes of the present invention has an average particle size in the range of 0.5 μm or more and 20 μm or less and has different average particle sizes. It is characterized in that a conductive powder obtained by mixing a plurality of conductive powders is dispersed in a liquid epoxy resin. By using such a conductive paste, the above-mentioned problems such as dents during filling can be solved. In the present invention, the “average particle diameter” means “median value of volume frequency distribution”.

Next, the circuit board of the present invention is characterized in that the conductive paste is filled in a via hole opened in the thickness direction of the insulating material, and a circuit is formed on the surface of the insulating material. To do.

Next, according to a first method of manufacturing a circuit board of the present invention, a through hole is provided in a compressible porous substrate having a release film, and the conductive paste is placed in the through hole. Filling, peeling the release film from the porous substrate filled with the conductive paste in the through-hole, overlaying the metal foil on both sides of the release film of the porous substrate, The porous base material on which the metal foils are stacked is heated and pressed to be compressed.

Next, in a second method for manufacturing a circuit board of the present invention, a through hole is provided in an insulating material having adhesive layers formed on both surfaces, the through hole is filled with the conductive paste, and A supporting base material having a wiring layer formed in a predetermined pattern is overlaid on at least one surface of the insulating material, and the insulating material overlaid with the supporting base material is heated and pressed to bury the wiring layer in the adhesive layer. Then, the supporting base material is removed while leaving the wiring layer.

Next, the third method for manufacturing a circuit board of the present invention is one in which a supporting base material having a wiring layer formed in a predetermined pattern and an insulating material having adhesive layers formed on both surfaces are laminated. , Heating and pressing in the thickness direction to temporarily press-bond, form a through hole that penetrates only the insulating material toward the wiring layer, fill the conductive paste in the through hole, and form the insulating material on the insulating material. Manufacturing of a circuit board, characterized in that a metal foil or a supporting substrate having a wiring layer formed on a predetermined pattern is laminated, and the wiring layer is embedded in the adhesive layer by heating and pressing again in the thickness direction. Method.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the conductive paste for filling via holes has an average particle size of 0.5 μm or more and 2.0 or more.
Conductive powder A in the range of μm or less and average particle size of 2.0 μm
It is preferable that a mixture of the conductive powder B in the range of more than 20 μm and less than 20 μm is dispersed in the liquid epoxy resin. Here, the conductive powder A plays a role of increasing the filling amount of the conductive powder in the via hole having a reduced diameter. On the other hand, conductive powder B
Is hard to be caught by a squeegee, etc., and plays a role of not causing a dent when filling. By mixing the conductive powder A and the conductive powder B in this way, the filling amount of the conductive powder in the via hole can be increased, and the problem in the filling process can be solved.

Further, in the conductive paste for filling via holes of the present invention, the mixing ratio of the conductive powder A is in the range of 10 to 50% by weight, and the mixing ratio of the conductive powder B is in the range of 50 to 90% by weight.
It is preferably in the range of. When the weight ratio is within this range, the above effect is more remarkable.

The average particle size is 0.5 μm or more and 2.0 μm or less.
A mixture of the conductive powder A having an average particle size of 2.0 m or less and the conductive powder B having an average particle size of 2.0 μm or more and 20 μm or less, and the total number of particles of the conductive powder of 2.0 μm or less is Is preferably 75% or more. If the particle number ratio is within this range, the above effect is more remarkable.

Further, it is preferable that the particle size distribution of the conductive powder has a plurality of peaks, and the peaks are in the range of 0.5 μm or more and 20 μm or less. Even when two kinds of conductive powders are not mixed, it is possible to manufacture the conductive powder having two peaks in the particle size distribution by adjusting the manufacturing conditions of the conductive powder. For example, particles having a specific particle size may be classified using a mesh or the like. Also in this case, as in the case of the above-mentioned conductive paste, the conductive powder having a particle size in the vicinity of the peak with a small particle size plays a role of increasing the filling amount of the conductive powder in the via hole having a reduced diameter. On the other hand, the conductive powder having a particle size in the vicinity of the peak having a large particle size plays a role of solving the problem at the time of filling. Therefore, by using such a conductive powder, the filling amount of the conductive powder in the via hole can be increased, and the problem at the filling process can be solved.

Further, the particle size distribution of the conductive powder has two peaks, and the first peak is 0.5 μm or more and 2.0 μm or more.
It is preferable that the second peak is in the range of 2.0 μm or less and 20 μm or less. The above effect is more remarkable when the particle size distribution has a peak in this range.

Further, the conductive powder A having an average particle size of 0.5 to 2.0 μm and the conductive powder B having an average particle size of 2.0 to 20 μm are mixed, and the number of particles of 2.0 μm or less is mixed. It is preferable to disperse the conductive powder having a content of 75% or more in the liquid epoxy resin. Here, the conductive powder A plays a role of increasing the filling amount of the conductive powder in the via hole having a reduced diameter. On the other hand, the conductive powder B plays a role of solving the problem at the time of filling. By mixing the conductive powder A and the conductive powder B in this way, the filling amount of the conductive powder in the via hole can be increased, and the problem in the filling process can be solved.

Further, the conductive powder has at least one fine particle selected from gold, platinum, silver, palladium, copper, nickel, tin, lead and alloys thereof, or conductive or non-conductive particles as a core, and gold, The fine particles coated with at least one metal selected from platinum, silver, palladium, copper, nickel, tin, lead or alloys thereof, or a mixture of these fine particles is preferable.

The circuit board of the present invention is characterized in that the conductive paste is filled in a via hole formed in an insulating material. Such a circuit board manufacturing intermediate has a high filling amount of the conductive powder in the via hole, and further has a small dent of the paste on the via surface. Therefore, a circuit board having high reliability can be manufactured by manufacturing the circuit board by the manufacturing method described in the above-mentioned conventional technique using such an intermediate for manufacturing a circuit board.

In the circuit board of the present invention, the via hole diameter is limited, and the above effect is more remarkable when the via hole diameter is 100 μm or less.

According to the first method of manufacturing a circuit board of the present invention, by filling the via hole with the above-mentioned conductive paste for filling via holes, the paste dent on the surface of the via holes is eliminated, and the conductive paste is more effectively formed. Since it can be compressed, a highly reliable circuit board can be manufactured.

In the above-mentioned manufacturing method, it is preferable that the compressible porous substrate is a composite material of aramid fiber and thermosetting epoxy resin. By using such a porous substrate, the above effects are more remarkable.

According to the second method of manufacturing a circuit board of the present invention, the paste dent on the surface of the via hole is eliminated,
Since the conductive paste can be compressed more effectively, a highly reliable circuit board can be manufactured.

According to the third method for manufacturing a circuit board of the present invention, the paste dent on the surface of the via hole is eliminated,
Since the conductive paste can be compressed more effectively, a highly reliable circuit board can be manufactured.

In the manufacturing method of the present invention, it is preferable that the insulating material before being heated and pressed is a film containing an organic material as a main component, and the adhesive layer is a semi-cured organic resin. By using such an insulating material, the above effects are more remarkable.

The diameter of the via hole formed in the insulating base material is preferably 100 μm or less. By forming the via hole having such a small diameter, the above effect is more remarkable.

The median value of the volume frequency distribution in the present invention is
Conductive powder is dispersed in water, by laser light diffraction method,
The particle size distribution (volume distribution of particles) is measured. The median of this distribution is the average particle diameter.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

(Embodiment 1) FIG. 1 is a process sectional view showing a method of manufacturing a double-sided circuit board according to this embodiment. First, as shown in FIG. 1A, a peelable film (also referred to as a release film) 100 made of polyester or the like is laminated on the surface of an insulating base material having semi-cured resin adhesive layers on both sides. Here, as the material of the insulating base material 101, a film mainly composed of an organic material can be used. For example, a polyimide film, an aramid film, a liquid crystal polymer film, etc. may be mentioned. Further, an epoxy adhesive or an imide adhesive can be used as the resin adhesive layer 102 provided on both sides of the insulating base material 101. Next, as shown in FIG. 1B, the release film on one side is peeled off, and the supporting substrate 10
It is laminated on the wiring pattern 104 formed on 3. Next, as shown in FIG. 1C, through holes 105 are formed at predetermined positions in the laminated body 1A by using a laser processing method or the like.
To form. Here, the through hole is preferably a hole that penetrates only the insulating base material 101 and the resin adhesive layer 102 formed on both sides thereof. Subsequently, as shown in FIG. 1D, the conductive paste 106 is filled in the through holes using a squeegee 110 or the like. Hereinafter, this state is referred to as a circuit board manufacturing intermediate 1D. Next, as shown in FIG. 1E, the release film adhered to the laminate 1D is peeled and removed. Then, the copper foil 107 or the wiring pattern formed on the supporting base material is laminated on the surface of the laminated body 1E, and is heated while being compressed along the thickness direction of the circuit board. When a copper foil is laminated as shown in FIG. 1F, a desired wiring pattern 108 is formed by using an etching method or the like, whereby a double-sided circuit board 1F is obtained. When the wiring patterns formed on the supporting base material are laminated in FIG. 1 (e),
After heating while compressing along the thickness direction of the circuit board,
By removing the supporting base material, the double-sided circuit board 1F is obtained.

(Embodiment 2) The manufacturing method of the present invention is not limited to the manufacture of a double-sided circuit board, and the same applies to the case of a multilayer circuit board in which a plurality of layers are laminated by repeating the manufacturing method of Embodiment 2 a plurality of times. It is possible to manufacture As an example, FIG. 2 is a process sectional view showing a method of manufacturing a circuit board called a three-layer circuit board. First, as shown in FIG. 2A, from one side of the double-sided circuit board manufactured in FIG.
The double-sided circuit board 2A2 before removing the laminated body 2A1 and the supporting base material of (a) is prepared. Next, as shown in FIG. 2B, the peelable film 100 on one side of the laminate 2A1 is peeled from one side of the double-sided circuit board 2A2 and laminated on the double-sided circuit board. Next, as shown in FIG. 2C, through holes are formed at predetermined positions by using a laser processing method or the like. Also in this case, the through hole is preferably a hole that penetrates only the insulating material 201 and the resin adhesive layers 202 formed on both sides thereof. Then, as shown in FIG. 2D, the conductive paste 20 is filled in the through holes by using a squeegee 110 or the like.
Fill 6. Next, as shown in FIG. 2E, the release film 100 adhered to the circuit board manufacturing intermediate 2D.
Peel off and remove. Then, a copper foil or a wiring pattern formed on a supporting base material is laminated on the surface of the laminated body 2E and heated while being compressed in the thickness direction. Also in this case, as shown in FIG. 2F, when a copper foil is laminated, a three-layer circuit board can be manufactured by forming a desired wiring pattern by using an etching method or the like. When the wiring pattern formed on the supporting base material is laminated, the supporting base material is removed to obtain the three-layer circuit board 2F. The above is the basic method for manufacturing the circuit board according to the present embodiment.

(Embodiment 3) The following double-sided circuit board was manufactured using the above-described method for manufacturing a double-sided circuit board. Insulating material is 5 on both sides of 12.5μm thick polyimide film.
The one coated with an imide adhesive with a thickness of μm was used.
A polyethylene film having a thickness of 9 μm was used as the release film. 9μ for the conductor layer that forms the wiring pattern
An m-thick copper foil was used. As the conductor paste composition to be filled in the via hole, bisphenol F type epoxy resin (“Epicoat 807” manufactured by Japan Epoxy Resin Co., Ltd.) was used with respect to 90% by weight of conductive powder (copper powder) mixed as shown in (Table 2). ) 2.6% by weight of dimer acid diglycidyl ester type epoxy resin ("Epicoat 871" manufactured by Japan Epoxy Resins Co., Ltd.) and 6.1% by weight of epoxy main agent to amine adduct type curing agent ("Amikyu MY-2 manufactured by Ajinomoto Co.
4 ") 1.3 wt% was added to the resulting vanider, and the mixture was kneaded with a three-roll mill to obtain a conductive paste.

As the liquid epoxy resin in the present invention, in addition to the above-mentioned bisphenol F type epoxy resin, glycidyl ether type epoxy resin such as bisphenol A type epoxy resin and bisphenol AD type epoxy resin, finger ring type epoxy resin, glycidyl amine. It is possible to use an epoxy resin containing two or more epoxy groups, such as an epoxy resin of the type and a glycidyl ester type epoxy resin.

An epoxy compound having one epoxy group can also contain the above-mentioned epoxy resin main agent as a reaction diluent. Further, in addition to the epoxy resin, it is also possible to form a conductive paste by using a polyimide resin, a sisocyanate ester resin, a phenol resole resin, or the like as the main component of the binder.

As described above, the above-mentioned conductive paste is of a so-called solventless type, but butyl cellosolve, ethyl cellosolve, butyl carbitol, ethyl carbitol may be used as necessary for adjusting printing characteristics. Additives such as a solvent and a dispersant such as butyl carbitol acetate, ethyl carbitol acetate, and α-terpineol can also be included. The conductive powder before mixing is shown in (Table 1). The average particle diameter (D50) was measured by dispersing the conductive powder of each sample in water by a laser light diffraction method (Microtrack HRA, model: 9320- × 100, laser light wavelength: 780 nm, laser output: 3 mW). .

[0034]

[Table 1]

[0035]

[Table 2]

Regarding the evaluation of the dent of the conductive paste at the time of filling the paste (hereinafter referred to as paste printability evaluation), the circuit board manufacturing intermediate after filling (1 in FIG. 1 (d)) was used.
D) The cross section of the via hole is observed, and the dent is larger than the release film (when the height of the conductive powder that is farthest from the release film is lower than the height of the release film) Was evaluated as x, and those having a thickness smaller than the thickness of the release film were evaluated as o. FIG. 3 shows an image diagram of the evaluation. Figure 3
It is a conceptual sectional view of intermediate 1D for circuit boards of (a). FIG. 3B is a partially enlarged view of P in FIG. 3A in Comparative Example 2. The conductive powder E is dented when the conductive paste is filled, and in such a state, poor conduction may occur. Therefore, the paste printability is set to x. 3C is a partially enlarged view of P in FIG. 3A in the sample 3 of the present embodiment. Since the conductive powder A + E was filled up to the height of the release film when the conductive paste was filled, and the conductivity in such a state was good, the paste printability was rated as ◯.

A PCT (Pressure Cooker Test) test was conducted to evaluate the connection reliability of the circuit board. 1
The sample was exposed to a saturated vapor pressure of 21 ° C. and 2 atmospheres.
This electrical resistance is taken out from the test device every
The electrical resistance of a circuit in which via holes were connected in series was measured by the 4-terminal method. A product having a resistance variation of less than 10% at a PCT loading time of 300 hours was regarded as a good product. The number of tests for each sample is 20. The two types of evaluation results are shown in (Table 3).

[0038]

[Table 3]

Compared with Comparative Examples 1 and 2, when two kinds of conductive powders were mixed, the conductive powder having 2.0 or less and 2.0 or less were mixed.
It can be seen that the sample in which a larger conductive powder is mixed has an effect on paste printability and connection reliability. The copper powder used for the evaluation or the conductive powder obtained by plating the copper powder with another metal, such as silver, is easily oxidized if the average particle size is smaller than 0.5 μm. The viscosity of the conductive paste increases rapidly, making printing difficult. Further, there is a problem that it is difficult to manufacture conductive powder having an average particle size of more than 20 μm. Therefore, here
Conductive powder having an average particle size of 2.0 μm and 2.0 to 20 μm
It can be said that the above effect is obtained when the conductive powder having the average particle diameter of m is mixed.

Further, it can be seen that also in the case of sample 7, the paste printability and the connection reliability are effective. Therefore, the above effect is not limited only when two kinds of conductive powders are mixed.

The diameter of the via hole of the sample evaluated here is 50 μm. Next, the same evaluation was performed using Sample 5 and Comparative Examples 1 and 2 with via hole diameters of 50, 100 and 120 μm. The evaluation results are shown in (Table 4).

[0042]

[Table 4]

As described above, in the case where the via hole diameter is larger than 100 μm, the difference between Comparative Example 1 and Sample 5 is not so different. Therefore, it can be said that the effect of the conductive paste according to the present invention is more remarkable when the via hole diameter is 100 μm or less.

(Embodiment 4) The conductive powders A and E used in Embodiment 3 were used to prepare a double-sided board in the same manner as in Embodiment 1 by changing the mixing weight ratio, and to make paste printability and connection. The reliability was evaluated. Table 5 shows a sample list and evaluation results.

[0045]

[Table 5]

When two kinds of conductive powders are mixed in this way, when compared with Samples 10 and 16, when the mixing weight ratio of the conductive powders having a small particle diameter is 50% or less, the paste printability is obtained. It can be seen that the connection reliability is improved. However, when it exceeds 60%, it can be said that the effect is reduced.

Here, only the case where the conductive powders A and E were mixed was taken as an example, but the conductive powder having an average particle size of 0.5 to 2.0 μm and 2.0 to 20 μm described in the first embodiment are used. The same effect is expected when the conductive powder of (1) is mixed.

Next, in the mixed conductive powders of Samples 11 to 15, the particle number distribution of the conductive powder having a particle size of 2.0 μm or less was measured by the laser light diffraction method (similar to that described in the third embodiment). The evaluation results are shown in (Table 6).

[0049]

[Table 6]

Considering this result together with the result of the above (Table 5), when the number of particles of the conductive powder having an average particle size in the range of 0.5 to 2.0 μm is 75% or more, the paste printability is improved. And it can be said that it has an effect on connection reliability.

The above-mentioned effects are not limited to the intermediate for manufacturing a double-sided circuit board, and the same effect can be obtained in a multilayer circuit board in which a plurality of insulating materials are laminated.
For example, the same effect can be obtained in the intermediate for manufacturing the three-layer circuit board shown in 2D in FIG. 2D.

(Embodiment 5) The effects of the conductive pastes shown in Embodiments 3 and 4 are not limited to the circuit board manufactured by the above manufacturing method. For example, the same effect can be obtained with a circuit board manufactured by the following method.

FIG. 4 is a sectional view of steps showing the method of manufacturing a four-layer circuit board according to this embodiment in order.

First, as shown in FIG. 4 (a), an insulative material 402 having a compressibility, in which a release film 401 is adhered on both surfaces, is prepared. The release film 40
As 1, it is possible to use polyethylene terephthalate, polyester or the like. A preferable example of the insulating material 402 is a prepreg having a compressibility obtained by impregnating a base material with a thermosetting resin to be a semi-cured state and having a large number of pores dispersed therein. Suitable examples of the base material include aromatic polyamide fiber base material, glass cloth base material, glass non-woven cloth base material, aramid cloth base material, aramid non-woven cloth base material, liquid crystal polymer non-woven cloth base material and the like. Preferable examples of the thermosetting resin with which the base material is impregnated include phenol resin, naphthalene resin, urea resin, amino resin, alkyd resin, silicon resin, furan resin, unsaturated polyester resin, epoxy resin, polyurethane resin, etc. Other known thermosetting resins can be mentioned, and one or more arbitrarily selected from these can be combined.

Next, through holes 403 are formed at predetermined positions in the insulating material by using a laser processing method or the like.

Next, as shown in FIG. 4B, a conductive paste 404 is filled in the through hole 403 formed in the insulating material 402 using a squeegee or the like. At this time, the conductive paste used in the above embodiment is used.

Next, as shown in FIG. 4C, the insulating material 4
The releasable film 401 adhered to 02 is peeled off and removed. This state is called semi-finished product 4A.

Next, as shown in FIG. 4D, the insulating material 4
Copper foil 405 is laminated on both the upper and lower surfaces of 02. Then, the insulating material 402 and the copper foil 405 are pressed while being heated in the thickness direction.

Next, as shown in FIG. 4E, the insulating material 4
The wiring pattern 406 is formed by etching the copper foil 405 deposited on the surface of No. 02. In this way, the double-sided circuit board 4B can be formed.

Next, as shown in FIG. 4F, the semi-finished product 4A and the copper foil 405 are formed on both the upper and lower surfaces of the double-sided circuit board 4B.
Are stacked. Then, the laminated body is pressed while being heated along the thickness direction. Thereafter, similar to FIG. 4E, a predetermined wiring pattern 407 is formed by etching the copper foil 405 attached to the surface of the laminate. In this way, the four-layer circuit board 410 can be formed (FIG. 4G).

The method of manufacturing the circuit board as described above is not limited to the four-layer circuit board.

Even when the conductive paste described in the first and second embodiments is used in the method of manufacturing a circuit board, it is possible to manufacture a circuit board having both paste printability and connection reliability. Even in this case, the effect is remarkable when the via hole diameter is 100 μm or less as described in the first embodiment.

Further, in the present embodiment, the description has been made only in the case where a plurality of conductive powders are mixed, but if the manufacturing conditions of the conductive powders are selected, the plurality of conductive powders are not mixed and the average particle diameter becomes plural. A conductive powder having a peak can be produced. By using such conductive powder, the same effect can be obtained without mixing a plurality of conductive powders as described above.

[0064]

As described above, the conductive paste of the present invention is less likely to cause dents at the time of filling via holes formed in an insulating material and can be filled with high density. Therefore, the circuit board using this conductive paste is 100μ
Even in the case of a small-diameter via of m or less, high connection reliability can be realized.

[Brief description of drawings]

1A to 1F are cross-sectional views of manufacturing steps of a double-sided circuit board according to a first embodiment of the present invention.

2A to 2F are cross-sectional views of a manufacturing process of a three-layer circuit board according to a second embodiment of the present invention.

FIG. 3 is a paste printability evaluation diagram of the circuit board intermediate according to the third embodiment of the present invention.

4A to 4G are cross-sectional views of a manufacturing process of a four-layer circuit board according to a fifth embodiment of the present invention.

[Explanation of symbols]

100 peelable film 101 insulating material 102 resin adhesive layer 103 support substrate 104, 108, 406, 407 Wiring pattern 105 through hole 106 conductive paste 107 copper foil 110 squeegee 1A laminated body Intermediate for 1D circuit board manufacturing 1E laminate 1F double-sided circuit board 201 insulating material 202 resin adhesive layer 206 Conductive paste 2A1 laminate 2A2 double sided circuit board Intermediate for 2D circuit board manufacturing 2E laminate 2F 3 layer circuit board 301 Insulation material 302 resin adhesive layer 303 Support substrate 304 wiring pattern 305 through hole 306 Conductive paste 307,401 Release film 402 insulating base material 403 through hole 404 conductive paste 405 copper foil 410 3-layer circuit board 4A semi-finished product 4B double sided circuit board

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/11 H05K 1/11 N 3/40 3/40 K 3/46 3/46 G N S (72 ) Inventor Yasuhiro Nakatani 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Masayoshi Koyama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsuda Denki Sangyo Co., Ltd. 1006 City Kadoma, Matsushita Electric Industrial Co., Ltd. F term (reference) 4E351 AA04 AA16 BB01 BB31 BB49 CC11 CC17 CC20 DD04 DD05 DD06 DD12 DD19 DD20 DD21 DD58 EE01 EE02 EE03 GG16 5E317 AA24 BB12 BB13 BB14 BB14 BB15 BB14 BB15 BB14 BB14 BB15 GG16 5E346 AA06 AA12 AA15 AA22 AA32 AA43 AA51 CC04 CC10 CC32 CC33 CC37 CC38 CC39 EE06 EE09 EE12 EE13 FF01 FF18 GG15 GG19 GG28 HH11 HH31 5G301 DA02 DA05 DA06 DA10 DA 11 DA13 DA29 DA57 DD01

Claims (16)

[Claims] 1. A conductive epoxy powder having an average particle size in the range of 0.5 μm or more and 20 μm or less and a mixture of a plurality of conductive powders having different average particle sizes is dispersed in a liquid epoxy resin. A conductor paste composition for filling via holes. 2. A plurality of conductive powders having different average particle sizes,
The conductive powder A having an average particle size of 0.5 μm or more and 2.0 μm or less, and the conductive powder B having an average particle size of more than 2.0 μm and 20 μm or less are mixed, and the mixture according to claim 1. Conductor paste composition for filling via holes. 3. The blending ratio of the conductive powder A is 10 to 50% by weight.
The conductive paste composition for filling via holes according to claim 2, wherein the content of the conductive powder B is in the range of 50 to 90% by weight. 4. A conductive powder A having an average particle size of 0.5 μm or more and 2.0 μm or less, and an average particle size of more than 2.0 μm.
It is a mixture with the conductive powder B in the range of 0 μm or less, and the number of particles of the conductive powder of 2.0 μm or less is 75% of the whole.
The conductor paste composition for filling via holes according to claim 1, which is as described above. 5. The via-hole-filling conductor paste composition according to claim 1, wherein the particle size distribution of the conductive powder has a plurality of peaks, and the peaks are in the range of 0.5 μm or more and 20 μm or less. 6. The particle size distribution of the conductive powder has two peaks, the first peak is in the range of 0.5 μm to 2.0 μm, and the second peak is more than 2.0 μm and 20 μm.
The conductor paste composition for filling via holes according to claim 1, which is in a range of m or less. 7. The conductor paste composition for filling via holes according to claim 6, wherein the number of particles of the conductive powder of 2.0 μm or less is 75% or more of the whole. 8. The conductive powder is gold, platinum, silver, palladium,
Gold, platinum, silver, palladium, copper, nickel, tin, lead or alloys of these, with at least one fine particle selected from copper, nickel, tin, lead and alloys thereof, or conductive or non-conductive particles as the core. The conductor paste composition for filling via holes according to any one of claims 1 to 7, which is a fine particle coated with at least one metal selected from the group consisting of or a mixture of these fine particles. 9. A circuit in which a conductive paste according to claim 1 is filled in a via hole opened in the thickness direction of an insulating material, and a circuit is formed on the surface of the insulating material. substrate. 10. The circuit board according to claim 9, wherein the diameter of the via hole formed in the insulating material is 5 μm or more and 100 μm or less. 11. A through-hole is provided in a compressible porous substrate provided with a release film, and the through-hole is filled with the conductive paste according to claim 1. The release film is peeled from the porous base material filled with the conductive paste in the through-hole, metal foil is laid on both sides of the release film of the porous base material, the metal foil, A method for manufacturing a circuit board, characterized in that the stacked porous base materials are heated and pressed to be compressed. 12. The compressible porous substrate is a composite material of aramid fiber and thermosetting epoxy resin.
A method for manufacturing a circuit board according to. 13. An insulating material having an adhesive layer formed on both sides thereof is provided with a through hole, the through hole is filled with the conductive paste according to claim 1, and at least one surface of the insulating material is provided. , A support substrate on which a wiring layer is formed in a predetermined pattern is overlaid, and the insulating material on which the support substrate is overlaid is heated and pressed to bury the wiring layer in the adhesive layer. The method for manufacturing a circuit board, wherein the supporting base material is removed while leaving the above. 14. A support base material having a wiring layer formed in a predetermined pattern and an insulating material having an adhesive layer formed on both surfaces thereof are laminated, and then heat-pressed in the thickness direction to temporarily press-bond the wiring material. A through hole that penetrates only the insulating material toward the layer is formed, the conductive paste according to any one of claims 1 to 8 is filled in the through hole, and a metal foil or a predetermined material is provided on the insulating material. A method for manufacturing a circuit board, comprising: stacking a support base material having a wiring layer formed in a pattern, and heating and pressing again in the thickness direction to bury the wiring layer in the adhesive layer. 15. The method for manufacturing a circuit board according to claim 13, wherein the insulating material before heating and pressurizing is a film containing an organic material as a main component, and the adhesive layer is an organic resin in a semi-cured state. 16. The method of manufacturing a circuit board according to claim 11, wherein the via hole formed in the insulating material has a diameter of 5 μm or more and 100 μm or less.