JPH0923067A - Multilayered printed wiring board and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered printed wiring board which can be constituted with simple means, provided with interlayer connection parts of high reliability, and restriction to wiring density and mounting density being reduced, and provide further a manufacturing method of the board. SOLUTION: This multilayered printed wiring board is equipped with a board type insulating substratum 1 having wiring patterns 2a, 2b and conductive material regions 3 which penetrate the insulating substratum 1 in the thickness direction and are buried so as to be mutually insulated and isolated. The conductive material regions 3 form laminated layer types of at least two kinds of conductive composites 3a, 3b different in physical properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board and a method for manufacturing the same, and more particularly, to a projection-shaped conductive composition which is inserted in the thickness direction of an insulating base material to electrically connect the layers. TECHNICAL FIELD The present invention relates to a multilayer printed wiring board having various connections and a manufacturing method thereof.

[0002]

2. Description of the Related Art Multi-layer printed wiring boards such as double-sided printed wiring boards and multi-layer printed wiring boards have been widely put into practical use as means for making circuit devices compact. In this type of multilayer wiring board, the wiring pattern layers are multilayered in response to the demand for higher density and higher functionality of the circuit device. Further, in the multilayer wiring pattern, the connection between the wiring pattern layers is generally performed by forming a conductive layer by plating, for example. The step of connecting the wiring pattern layers will be further described. For example, first, a double-sided copper-clad laminate is punched. Next, the entire surface including the inner wall surface of the formed hole is subjected to chemical plating, and further electroplating is performed to thicken the metal layer on the inner wall surface of the hole to enhance reliability. After that, the copper layers on both surfaces are subjected to, for example, photoetching treatment to perform required patterning, and then, if necessary, a copper foil is laminated and arranged on the patterned surface via an insulator layer (for example, a prepreg layer), Pressurize and integrate. With the copper foil integrated with the insulator layer, the steps of punching, plating to electrically connect the layers and pattern the copper foil are repeated to obtain the required multilayer wiring board.

In order to simplify the step of electrically connecting the wiring pattern layers together with the above-mentioned plating treatment, for example, a double-sided copper-clad laminate is perforated, and a conductive paste filled in the holes by a printing method or the like is used. There is also known a method of curing and connecting layers. In addition, the tip end of the protruding conductor (conductive bump) made of a conductive paste is inserted in the thickness direction of the insulating layer interposed as the interlayer insulating material, and the conductive (wiring pattern) surface facing the conductive layer is formed. A method of making electrical connection by contact or pressure contact has also been proposed.

[0004]

However, in the above-mentioned multilayer printed wiring board, in order to form the interlayer connection portion,
Not only does the manufacturing process add holes such as drilling and copper plating, which makes the process redundant, but it also takes a lot of time for drilling because each hole is drilled by a drill in the drilling process. Requires. Further, since it is necessary to make a hole accurately with consideration of the plating adhesion of the inner wall surface of the hole, a large-scale device is required and the management of conditions is complicated. In addition, in the plating process,
There is a problem that process control such as concentration control of chemicals and temperature control is complicated.

On the other hand, in the holes for electrical connection between the wiring layers,
The method of embedding the conductive paste by printing or the like also requires a drilling step as in the case of the plating method. Moreover, it is difficult to evenly (uniformly) pour and embed the conductive paste into the bored holes, and there is a problem in reliability of electrical connection.

In any case, the need for the drilling process is reflected in the cost and yield of the multilayer printed wiring board, and it is not possible to meet the demand for cost reduction, and further, for high density wiring. Along with this, if the diameter of the drilled hole is relatively small, there is a drawback that it is difficult to achieve highly reliable electrical connection by plating or filling with a conductive paste. Also, in the configuration in which electrical connection is made between layers through the holes that are drilled, conductor holes are installed on the front and back surfaces of the multilayer printed wiring board, so wiring is formed and arranged in the area of the conductor holes. This is not possible, and since electronic components cannot be mounted in addition, improvement in wiring density and mounting density is restricted. In other words, the multilayer printed wiring board adopting the through-hole connection method makes the circuit device compact by high-density wiring and high-density mounting,
Consequently, it cannot be said that it can sufficiently meet the demand for miniaturization of electronic devices.

With respect to the above-mentioned means, the tip end portion of the protruding conductor (conductive bump) is inserted in the thickness direction of the insulating layer interposed as the interlayer insulating material, and the opposing conductive material (wiring pattern) surface is formed. The method in which electrical connection is made by contacting or press-contacting with is simple in process, and the wiring density and the mounting density can be improved. In other words, it is expected as a practically effective multilayer printed wiring board and a manufacturing method in terms of cost, but there is still room for improvement and improvement for more effective practical use.

The present invention has been made in view of the above circumstances, and is a multilayer printed wiring board which can be constructed by simple means and has a highly reliable interlayer connecting portion, and in which restrictions on wiring density and mounting density are reduced. , And its manufacturing method.

[0009]

According to a first aspect of the present invention, a plate-like insulating base material having a wiring pattern and the insulating base material are embedded in the insulating base material so as to penetrate the insulating base material in the thickness direction. A multilayer printed wiring board having a conductive material region, wherein the conductive material region has at least two different physical properties.
It is a multilayer printed wiring board characterized by being formed in a laminated type with one kind of conductive composition.

According to a second aspect of the present invention, there is provided a plate-like insulating base material provided with a wiring pattern, and a conductive material region embedded in the insulating base material in a thickness direction so as to be insulated and separated from each other. It is a multilayer printed wiring board provided, wherein the conductive material region is formed in a laminated type with at least two kinds of conductive compositions having different composition components from each other.

According to a third aspect of the present invention, a step of forming a protrusion with a first conductive paste at a predetermined position on the support, and a step of forming the first conductive paste on the protrusion surface made of the first conductive paste. And a step of laminating and forming a protrusion with a second conductive paste having different physical properties, and a step of laminating and placing a synthetic resin-based insulator layer and a conductive foil on the surface side on which the laminated protrusion is formed, A step of pressurizing and integrating the laminate to electrically connect the tips of the laminated protrusions having the insulating layer inserted thereto to the surface of the opposing conductive foil by pressure, and wiring the conductive foil; And a step of patterning, which is a method for manufacturing a multilayer printed wiring board.

According to a fourth aspect of the present invention, there is provided a step of forming a protrusion with a first conductive paste at a predetermined position of the wiring pattern,
A step of stacking and forming a protrusion on the protrusion surface made of the first conductive paste with a second conductive paste having physical properties different from those of the first conductive paste; and a surface side on which the laminated protrusion is formed. A step of laminating and placing a synthetic resin-based insulating layer and a conductive foil, and a conductive foil in which the tips of the laminated protrusions through which the insulating layer is inserted face each other by pressing and unifying the laminated body. A method for manufacturing a multilayer printed wiring board, comprising: a step of pressingly contacting a surface to electrically connect the surface and a step of wiring patterning the conductive foil.

According to a fifth aspect of the present invention, the laminated protrusion is formed of a thermoplastic resin-based conductive paste and a curable resin-based conductive paste. It is a manufacturing method of a multilayer printed wiring board.

According to a sixth aspect of the present invention, the multilayer protrusion is formed of a soft resin-based conductive paste and a hard resin-based conductive paste. It is a method of manufacturing a wiring board.

In the present invention, examples of the supporting substrate on which the conductive protrusions are formed include synthetic resin sheets having good releasability or conductive sheets (foil). The supporting substrate is more preferably a single sheet from the viewpoint of workability, but it may be patterned in advance and its shape is not particularly limited.

In the present invention, the conductive protrusions are formed in a laminated type by using two or more kinds of conductive compositions having different physical properties as materials. For example, the primary protrusions are resin-based conductive pastes or thermosetting resin-based conductive pastes that have a relatively high hardness when they are dried, and the primary protrusions are provided on the primary protrusions in a laminated manner. The secondary projection may be formed of a soft (or thermoplastic) resin-based conductive paste having good adhesion or a relatively brittle UV-curable or electron beam-curable resin-based conductive paste. Alternatively, the primary projections may be formed of a soft (or thermoplastic) resin-based conductive paste having good adhesion or a relatively brittle UV-curable or electron beam-curable resin-based conductive paste, and the secondary It is also possible to adopt a mode in which the protrusions are formed from a resin-based conductive paste or a thermosetting resin-based conductive paste having a relatively high hardness when dried. Here, as the conductive paste used for forming the conductive protrusions, for example, conductive powder such as silver, gold, copper, solder powder, alloy powder or composite (mixed) metal powder of these, and resin binder component It was prepared by mixing Here, as the resin-based binder component, for example, a thermosetting resin such as a polycarbonate resin, a polysulfone resin, a polyester resin, or a phenoxy resin, or a thermosetting resin such as a phenol resin, a polyimide resin, or an epoxy resin is generally used. . Others, methyl methacrylate,
Diethyl methyl methacrylate, trimethylol propane triacrylate, diethylene glycol diethyl acrylate, methyl acrylate, ethyl acrylate,
Diethylene glycol ethoxylate acrylate, ε-
Examples thereof include an acrylic acid ester such as an acrylate of caprolactone-modified dipentaerythritol, an ultraviolet curable resin such as a methacrylic acid ester, or an electron beam irradiation curable resin. The difference in the physical properties of the conductive composition is generally made by selecting the composition component, but it may be made by selecting and setting the composition ratio.

It is desired that the electrically conductive composition has a required electrical conductivity, has a certain viscosity in an undried state, and exhibits a certain degree of hardness upon drying. The protrusions (columnar bodies) of the organic composition can be formed by, for example, a printing method using a relatively thick metal mask to form protrusions (columnar bodies) having a high aspect ratio. And the distribution are appropriately set according to the configuration of the through-type conductor wiring portion to be formed. Specifically, it is decided in consideration of the layout structure of the through-type conductor wiring part that is finally configured. For example, if the synthetic resin sheet is a B-stage epoxy resin layer containing glass cloth, press fit from both sides. When the form
About 80 to 120% of the thickness of the B-stage epoxy resin layer, and in the case of press fitting from one side, a height of about 180 to 220% of the thickness of the B-stage epoxy resin layer is preferable. The protrusions (columnar bodies) are arranged, for example, in a predetermined position of a stainless steel plate having a thickness of about 5 mm by arranging a mask having a hole of 0.3 mm on the entire surface of the casing and then storing the mask in the casing. A stamp method in which the conductive composition (paste) of No. 1 is pressed to push the conductive composition out of the holes of the mask;
The electrically conductive composition (paste) may be pressed to sequentially press the electrically conductive composition through the holes of the mask.

In the present invention, examples of the synthetic resin-based sheet into which the conductive protrusions are inserted to form the through-hole type conductor wiring portion include a thermoplastic resin film (sheet) having a thickness of 50. It is preferably about 800 μm. Here, examples of the thermoplastic resin sheet include sheets such as polycarbonate resin, polysulfone resin, thermoplastic polyimide resin, polyethylene tetrafluoride resin, polypropylene hexafluoride resin, and polyether ether ketone resin. Further, as the thermosetting resin sheet to be kept in the state before curing, epoxy resin, bismaleimide triazine resin, polyimide resin, phenol resin, polyester resin, melamine resin, or butadiene rubber, butyl rubber, natural rubber, neoprene rubber, silicone Examples include raw rubber sheets such as rubber. These synthetic resins may be used alone or may contain an insulating inorganic or organic filler, and are a sheet formed by combining with a reinforcing material such as glass cloth or mat, organic synthetic fiber cloth or mat, or paper. It may be.

Furthermore, in the present invention, an insulating layer and a conductive layer (conductive foil) are sequentially laminated and arranged on the surface of a supporting substrate on which conductive conductive protrusions (columnar bodies) of laminated type are formed. When applying heat and pressure to the laminate, metal plates or heat-resistant resin plates with little size and deformation, such as stainless steel plates, brass plates, polyimide resin plates (sheets), polytetrafluoroethylene resin plates (sheets) are used as pad plates on both sides. ) Is preferable. Further, when the laminated body is pressed while the resin component of the insulator layer is softened by heating, the conductive protrusions can easily penetrate the insulator layer.

[0020]

According to the first aspect of the present invention, the conductive material region for connecting the wiring layers in a penetrating manner is formed in at least two kinds of conductive compositions having different physical properties, for example, a laminated type of hard layer / soft layer. As a result, the required penetration and contact are ensured, and intimate contact and connection are also formed, thus functioning as a multilayer printed wiring board having highly reliable interlayer connection. According to the second aspect of the invention, the conductive material region that connects the wiring layers in a penetrating manner is formed in at least two kinds of conductive compositions having different physical properties, for example, a laminated type of a toughness layer / weakness layer. Therefore, while the required penetration and contact are ensured, a close contact and connection are also formed, and it functions as a multilayer printed wiring board having highly reliable interlayer connection.

According to the third and fourth aspects of the present invention, the laminated body is pressed and integrated so that the insulating layer having the tip of the laminated projection interposed is inserted and pressed against the opposing conductive foil surface. When electrically connected to each other, the physical properties (eg, hard layer / soft layer, tough layer / fragile layer) of each conductive composition forming the stacked protrusions exert their respective characteristics, Since a good interlayer connection is easily formed, a highly reliable multilayer printed wiring board can be manufactured with a high yield.

According to the fifth and sixth aspects of the invention, the laminated protrusion is formed of a thermoplastic resin / curable resin system or a soft resin / hard resin system. The operation described in item 4 becomes more effective.

[0023]

EXAMPLE FIG. 1, FIG. 2 (a)-(c) and FIG. 3 (a)-(c)
An embodiment of the present invention will be described with reference to FIG. First, five kinds of conductive compositions were prepared as follows.

(A) 90% by mass of silver powder (average particle size 10 μm),
And trimethylolpropane triacrylate resin 10
An ultraviolet-curable conductive resin paste composed of mass% was prepared and kneaded with a three-roll type kneader to prepare a hard and easily crushed conductive paste (conductive composition A).

(B) 94% by mass of silver powder (average particle size 10 μm),
And ethylene glycol diacrylate resin 6% by mass
Prepare a UV curable conductive resin paste consisting of 3
The mixture was kneaded with the present roll type kneader to prepare a conductive paste (conductive composition B) which is soft and has good adhesion.

(C) 85% by mass of silver powder (average particle size 10 μm),
And a thermosetting conductive resin paste consisting of 15% by mass of epoxy resin (trade name, Epicoat 828 / Epicoat 1001, manufactured by Shell Co.), kneaded with a three-roll type kneader, and has good flexibility and good adhesion. A conductive paste (conductive composition C) was prepared.

(D) 88 mass% of silver powder (average particle size 10 μm),
And epoxy resin (trade name, Cresol Novolac E
OCN-89, manufactured by Sumitomo Chemical Co., Ltd.) A thermosetting conductive resin paste consisting of 12% by mass was prepared and kneaded with a three-roll type kneader to give a hard, brittle and highly conductive conductive paste (conductive composition Material D) was prepared.

(E) 90% by mass of silver powder (average particle size 10 μm),
And polysulfone resin (trade name, thermoplastic resin ERADE
L-PS, manufactured by Amco Japan) 10% by mass of thermoplastic conductive resin paste is prepared and kneaded by a three-roll type kneader to prepare flexible conductive paste (conductive composition E). did.

Example 1 FIG. 1 is a cross-sectional view showing a structural example of a main part of a multilayer printed wiring board according to this example. Reference numeral 1 is a plate-like insulating base material provided with wiring patterns 2a and 2b, and 3 is the insulating material. Is a conductive material region that forms an interlayer connection portion that penetrates the flexible base material 1 in the thickness direction and is insulated and separated from each other. The conductive material region (interlayer connection portion) 3 has two kinds of conductive compositions having different physical properties.
3a and 3b, for example, the conductive composition A and the conductive composition B are formed in a laminated type.

Next, FIG. 2 (a) to FIG.
An example of manufacturing the multilayer printed wiring board will be described with reference to (c).

An electrolytic copper foil 4 having a thickness of 35 μm, which is generally used in the production of printed wiring boards, is prepared, and a mask having a hole of 0.4 mm in diameter is formed at a predetermined position on the surface of the electrolytic copper foil 4. The conductive composition A was screen-printed via the above, and then the conductive composition A was housed in an ultraviolet irradiation furnace and irradiated with ultraviolet rays. Thus, FIG.
As shown in a sectional view in (a), a hard and relatively fragile first conductive protrusion 5a serving as a base was formed. Then, the conductive composition B is screen-printed on the surface where the first conductive protrusions 5a are formed, and then the conductive composition B is housed in an ultraviolet irradiation furnace and irradiated with ultraviolet rays, as shown in a sectional view in FIG. Then, the protruding portion 5 in which the second conductive protruding portion 5b having flexibility and good adhesion is laminated is formed. The protrusion 5 had a required shape (height and diameter) and hardness.

Next, as shown in a sectional view in FIG. 2 (c), an epoxy prepreg layer 1'having a thickness of about 100 μm and an electrolytic copper foil 4'having a thickness of 35 μm are formed on the surface on which the conductive protrusions 5 are formed. They were stacked one after another. This laminated body is set in a pressing device and pressed at a temperature (for example, 120 ° C.) at which the epoxy prepreg layer 3 ′ is softened to insert the epoxy prepreg layer 1 ′ into the tip of the conductive protrusion 5. Then, a double-sided copper foil-clad laminate having an electrically connected portion (conductive material region) 3 formed by contacting and deforming the opposing copper foil 4'sides was manufactured. In the production of this laminated plate, a low resistance connection was formed because the tip of the conductive protrusion 5 penetrating the epoxy prepreg layer 1'is flexible and has good adhesion.

Then, with respect to the double-sided copper foil-clad laminate, an ordinary etching resist ink (trade name, PSR-
4000H, made by Taiyo Ink Co., Ltd.), the copper foils 4 and 4'sides are masked by screen printing so that a predetermined wiring circuit pattern is obtained, copper is etched with cupric chloride, and the resist mask is peeled off. A printed wiring board 6 having the required wiring circuit patterns 2a and 2b as shown in 1 was obtained. When a conventional electrical check was performed on this printed wiring board 6, there was no problem (abnormality) in all the connection parts.

Similar results were obtained by using the conductive composition C or the conductive composition E instead of the conductive composition B in the above. Of course, in this case, the irradiation of ultraviolet rays is omitted.

Example 2 According to the above-mentioned method, the conductive compositions A and B were screen-printed and ultraviolet-irradiated at predetermined positions on the wiring pattern 2a of the printed wiring board 6 prepared by the manufacturing method of the above-mentioned Example 1 to As shown in section 3 (a), a conductive protrusion 5 was formed by stacking the first conductive protrusion 5a and the second conductive protrusion 5b. Then, on the surface of the printed wiring board 6 on which the conductive protrusions 5 are formed, as shown in a sectional view in FIG.
An epoxy prepreg layer 1'of 100 μm and a printed wiring board 6 were sequentially laminated. This laminated body is set in a press machine and pressed at a temperature (for example, 120 ° C.) at which the epoxy prepreg layer 1 ′ is softened, and the conductive protrusions 5 are formed.
The leading end of each is contacted and deformed with the surface of the wiring pattern 2b of the printed wiring board 6 facing through the epoxy prepreg layer 1'through which the electrical connection (conductive material region) 3 is formed 4
A layered printed wiring board was manufactured.

In the heating / pressurizing step in the manufacturing process, since the tip end side of the conductive protrusion 5 is soft and the inner layer is hard,
The epoxy prepreg layer 1'is smoothly inserted without causing deformation of the peripheral portion, and after the insertion, the tip end side bulges and comes into close contact with the surface of the wiring pattern 2b. Here, for example, when heat treatment is performed at a temperature of about 150 ° C. for about 30 minutes, adhesion and bondability are improved, and the connection portion 3 having low interface resistance is formed. This multi-layer printed wiring board was subjected to a normal electrical check and found that all connection parts 3
There was no problem with reliability and there was no problem with reliability. Furthermore, in order to evaluate the connection reliability between the wiring pattern layers, a hot oil test (5 seconds immersion in 260 ° C oil, 15 seconds immersion in 20 ° C oil for 1 cycle) was performed for 500 cycles. No defects were found, and it was found that the connection reliability between the wiring pattern layers was significantly better than that of a conventional wiring board using a copper plating method.

Similar results were obtained by using the conductive composition C or the conductive composition E instead of the conductive composition B in the above. Of course, in this case, the irradiation of ultraviolet rays is omitted.

Example 3 In the case of Example 1, the electrolytic copper foil having a thickness of 18 μm was used in place of the electrolytic copper foil having a thickness of 35 μm, the conductive composition D was used in place of the conductive composition B, and the thickness was increased. A 50 μm-thick epoxy prepreg was used instead of the 100 μm-epoxy prepreg, but a double-sided copper foil-clad laminate was created under the same conditions, and the double-sided copper foil was wiring-patterned. A double-sided wiring board having a structure in which it was electrically connected at a through-type connection portion was prepared.

Next, on the double-sided wiring pattern surface of the double-sided wiring board, laminated conductive projections were formed by screen-printing, drying and curing the conductive composition A and the conductive composition D, respectively. Then, on the surface where the conductive protrusions are formed, a 100 μm thick epoxy prepreg and a thickness of
35 μm electrolytic copper foils were laminated and arranged. This laminated body is set in a pressing device and pressed at a temperature (for example, 120 ° C.) at which the epoxy prepreg layer is softened, and the tip end of the conductive protrusion is inserted into the epoxy prepreg layer to face the electrolytic copper. A double-sided copper foil-clad laminate having an electrical connection portion (conductive material region) formed by contacting and deforming the foil surface was manufactured.

In the heating / pressurizing step in the manufacturing process, since the tip end side of the conductive protrusion is soft and the inner layer part is hard, the epoxy prepreg layer can be smoothly inserted without causing deformation of the peripheral part. Also, after the insertion, the tip end side opens sharply and comes into close contact with and contacts the electrolytic copper foil surface. Here, for example, when heat treatment is performed at a temperature of about 150 ° C. for about 30 minutes, adhesion and bondability are improved, and a connection portion having low interface resistance is formed.

This double-sided copper foil-clad laminate was masked with a normal etching resist ink (trade name, PSR-4000 H, made by Taiyo Ink KK) to a predetermined wiring circuit pattern by screen printing. Copper was etched with cupric chloride and the resist was peeled off to obtain a multilayer printed wiring board having a required wiring circuit pattern.

When this multilayer printed wiring board was subjected to a normal electrical check, no problems were found in all the connecting portions 3 and there was no problem in reliability. Furthermore, in order to evaluate the connection reliability between the wiring pattern layers, a hot oil test (immersion in 260 ° C oil for 5 seconds, 20 ° C oil in
After 500 cycles of 15 seconds immersion (1 cycle), no defects were found and it was found that the connection reliability between the wiring pattern layers was significantly better than that of the conventional copper-plated wiring board. .

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the laminated conductive protrusions may be formed in three layers or more, and the insulating layer may be formed of a material other than epoxy resin.

[0044]

According to the first and second aspects of the present invention, the wiring layers are formed of, for example, a hard layer / soft layer or a tough layer / weak layer laminated conductive projection (region). Because each of these features is effectively used,
It is possible to provide a multilayer printed wiring board having a highly reliable inter-layer connection and a high wiring density and a high mounting density, as well as ensuring the required insertion and contact, and also forming a tight contact and connection.

According to the inventions of claim 3, claim 4, claim 5 and claim 6, while simplifying the process, on the other hand, the insulating layer is inserted by pressing and integrating the laminated body. Hardness / softness, toughness / weakness of each conductive composition forming the laminated protrusions exhibit their respective characteristics, and a good interlayer connection is easily formed. A multilayer printed wiring board having high density and mounting density can be provided with high yield.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a main part of a multilayer printed wiring board according to the present invention.

FIG. 2 schematically shows an example of a manufacturing process of a multilayer printed wiring board according to the present invention, where (a) is a cross-sectional view showing a state in which first conductive protrusions are formed on a support surface, and (b) is Sectional drawing which shows the state which laminated | stacked the 2nd electroconductive protrusion, (c) is sectional drawing which shows the state which laminated | stacked the insulator layer and the copper foil on the conductive protrusion part formation surface.

FIG. 3 schematically shows an example of a manufacturing process of the multilayer printed wiring board according to the present invention, in which (a) is a cross-sectional view showing a state where conductive projections are formed on the double-sided wiring board surface; () Is a cross-sectional view showing a state in which an insulating layer and a double-sided wiring board are stacked and arranged on the surface of the wiring board on which the conductive protrusions are formed, and (c) is a cross-sectional view of a multilayer printed wiring board integrated and laminated.

[Explanation of symbols]

 1 ... Insulating substrate 1 '... Prepreg (insulator layer) 2a, 2b ... Wiring pattern 3 ... Conductive material region (interlayer connection part) 3a ... First conductive material region 3b .. 2 conductive material area 4, 4 '... Electrolytic copper foil 5 ... laminated conductive projection 5a ... first conductive projection 5b ... second conductive projection 6 ... double-sided type Printed wiring board

Claims (6)

[Claims] 1. A multilayer printed wiring comprising: a plate-shaped insulating base material having a wiring pattern; and conductive material regions which penetrate the insulating base material in a thickness direction and are insulated and separated from each other. A multilayer printed wiring board, characterized in that the conductive material region is formed in a laminate type with at least two kinds of conductive compositions having different physical properties. 2. A multilayer printed wiring comprising: a plate-shaped insulating base material having a wiring pattern; and conductive material regions that penetrate the insulating base material in a thickness direction and are insulated and separated from each other. A multilayer printed wiring board, characterized in that the conductive material region is formed in a laminated type with at least two kinds of conductive compositions having different compositions. 3. A step of forming a projection with a first conductive paste at a predetermined position on a support, and a physical property different from that of the first conductive paste on the projection surface made of the first conductive paste. A step of stacking and forming a protrusion with a second conductive paste; a step of stacking and arranging a synthetic resin-based insulator layer and a conductive foil on the surface side on which the stacked protrusion is formed; Pressure-integrating, a step of press-contacting the tips of the laminated protrusions having the insulating layer inserted therethrough to the opposite conductive foil surface to electrically connect them, and a step of wiring patterning the conductive foil A method for manufacturing a multilayer printed wiring board, comprising: 4. A step of forming a protrusion with a first conductive paste at a predetermined position of a wiring pattern, and a physical property different from that of the first conductive paste on the protrusion surface made of the first conductive paste. A step of stacking and forming a protrusion with a second conductive paste; a step of stacking and arranging a synthetic resin-based insulator layer and a conductive foil on the surface side on which the stacked protrusion is formed; Pressure-integrating, a step of press-contacting the tips of the laminated protrusions having the insulating layer inserted therethrough to the opposite conductive foil surface to electrically connect them, and a step of wiring patterning the conductive foil A method for manufacturing a multilayer printed wiring board, comprising: 5. The multilayer printed wiring board according to claim 3, wherein the laminated protrusion is formed of a thermoplastic resin-based conductive paste and a curable resin-based conductive paste. Production method. 6. The method for manufacturing a multilayer printed wiring board according to claim 3, wherein the laminated protrusion is formed of a soft resin type conductive paste and a hard resin type conductive paste. .