KR20090068227A - Multilayer printed wiring board and method for manufacturing the same - Google Patents

Abstract

A method for manufacturing a multilayer printed wiring board with high productivity in which a multilayer printed wiring board excellent in connection reliability can be manufactured through a simple process. The method for manufacturing a multilayer printed wiring board comprises a step for preparing a double-sided substrate having a matrix, a first conductive layer provided on one surface of the matrix and a second conductive layer provided on the other surface of the matrix, a step for forming wiring by removing the first conductive layer and the second conductive layer selectively, a step for forming a blind via hole having the second conductive layer as the bottom and the matrix and the first conductive layer as the wall face by removing the matrix selectively, and a step for applying a conductive paste continuously to the outer circumference of the blind via hole, namely. the surface of the first conductive layer, and the base of the blind via hole. The manufacturing method is characterized in that the first conductive layer and the second conductive layer are connected electrically.

Description

Multilayer printed wiring board and manufacturing method therefor {MULTILAYER PRINTED WIRING BOARD AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a multilayer printed wiring board having a plurality of metal wiring layers and a method of manufacturing the same.

BACKGROUND ART A multilayer printed wiring board is known as a technology that enables high-density mounting of components and allows connections between components at shortest distances (meaning electrical conduction, hereinafter simply referred to as connection). IVH (Interstitial Via Hole) is a technique applied to the manufacture of multilayer printed wiring boards requiring higher density mounting, and is characterized by connecting adjacent layers by filling conductive materials in holes (via holes) formed between adjacent layers. do. According to IVH, the interlayer connection can be formed only in necessary portions, and components can be mounted on via holes, thereby enabling high-density wiring with high degree of freedom.

Patent Document 1 describes a method for producing a multilayer printed wiring board in which a blind via hole is filled with an electrically conductive paste and connected between layers. FIG.1 and FIG.2 is process drawing which shows the manufacturing process of this multilayer printed wiring board.

First, the copper foil surface of the single-side copper foil adhesive base material 3 which has the insulating base material 1 and the wiring layer 2 (copper foil) on one side is etched, and the wiring layer 2 is formed (FIG. 1B). Next, after laminating the film 4 for peeling on the opposite surface of the insulating base material 1 (FIG. 1C), a perforation process is performed and the blind via hole 5 is formed (FIG. 1D). After the electrically conductive paste 6 is filled in this via hole, the peeling film 4 is peeled off and the electrically conductive paste protrudes from the surface of an insulating base material (FIG. 1F).

The metal film 7 is laminated thereon (FIG. 2A), pressed to compress the conductive paste to electrically connect the metal film 7 and the wiring layer 2, and the metal film 7 is connected to the base 1. Adhesion (FIG. 2B). Thereafter, the metal film 7 is etched to form a wiring layer of the metal film 7, whereby a multilayer printed wiring board having two wiring layers can be obtained (FIG. 2C).

In addition, Patent Document 2 describes a method for producing a multilayer printed wiring board in which a metal is deposited in a blind via hole by electroplating without using a conductive paste. 3 is a process chart showing a manufacturing process of this multilayer printed wiring board.

First, after preparing the board | substrate 11 containing the base material 8, the 1st metal layer 9 formed in one surface side of the base material 8, and the 2nd metal layer 10 formed in the other surface side (FIG. 3A). The first metal layer 9 and the base material 8 are selectively removed to form holes 12 that reach the second metal layer 10 (FIG. 3B).

Next, electric power is supplied from the second metal layer 10 to perform electrolytic plating, and metal is deposited inside the hole 12 to fill the inside of the hole with the metal 13 (FIG. 3C). Thereafter, the first metal layer and the second metal layer are etched to form wiring, whereby a multilayer printed wiring board having two wiring layers can be obtained (FIG. 3D). The etching of the first metal layer may be performed before the formation of the holes 12.

Patent Document 1: Japanese Patent Application Laid-Open No. 2001-345555

Patent Document 2: Japanese Patent Application Laid-Open No. 2006-114787

(Initiation of invention)

(Tasks to be solved by the invention)

The conductive paste is obtained by dispersing conductive fillers such as metal powder in a resin binder, and contains a solvent for dissolving the resin. For this reason, the volume of the conductive paste decreases when the solvent is removed by heating, reduced pressure, or the like after applying the conductive paste. Moreover, by compressing an electrically conductive paste, the filling rate of an electrically conductive filler becomes high and electroconductivity improves. For this reason, in order to improve the connection reliability of a blind via hole connection, an electrically conductive paste should be apply | coated larger than the volume of a blind via hole, and like the patent document 1, an electrically conductive paste should be apply | coated so that an electrically conductive paste may protrude from the surface of an insulating base material.

However, in the method of patent document 1, the bonding and peeling of the peeling film 4 are needed, and a process becomes complicated. In addition, the etching of the wiring layer 2 and the etching of the metal film 7 should be performed by a separate process. This is because, in order to increase the interlayer connectivity between the wiring layer 2 and the metal film 7, the pressure must be equally applied during the pressing of the conductive paste, and the metal film 7 which has been etched in advance cannot be used.

In the method of patent document 2, a peeling film is not necessary. However, when depositing the metal by electroplating, if the plating grown from the bottom of the blind via hole contacts the surface of the first metal layer 9, the first metal layer 9 is also supplied with electric power to the surface of the first metal layer 9. The metal precipitates in and the thickness of the first metal layer 9 becomes thick, making it difficult to form thin wires. In order to prevent this, a coating layer can be formed on the surface of the first metal layer 9, but the process is complicated by that. In addition, in order to perform electroplating by supplying electric power from the second metal layer 10, the second metal layer 10 must be continuous, so that it is difficult to form the wiring by etching the second metal layer 10 before forming the blind via hole.

In view of the above problems, an object of the present invention is to provide a method for producing a highly productive multilayer printed wiring board that can produce a multilayer printed wiring board having excellent connection reliability in a simple step. Moreover, it aims at providing the multilayer printed wiring board which is excellent in connection reliability.

(Means for solving the invention)

The present invention provides a step of preparing a double-sided substrate having (1) a substrate, a first conductive layer formed on one surface of the substrate, and a second conductive layer formed on the other surface of the substrate, (2) the agent Selectively removing the first conductive layer and the second conductive layer to form a wiring, and (3) selectively removing the substrate to form the second conductive layer as a bottom surface, and to form the substrate and the first conductive layer. Forming a blind via hole having a wall surface; and (4) applying a conductive paste to the surface of the first conductive layer that is the outer circumference of the blind via hole and the bottom surface of the blind via hole. It is a manufacturing method of the multilayer printed wiring board which electrically connects a said 2nd conductive layer (claim 1).

It is process drawing which shows an example of the manufacturing method of the multilayer printed wiring board of this invention. A double-sided substrate 17 having a substrate 14, a first conductive layer 15 formed on one surface of the substrate and a second conductive layer 16 formed on the other surface of the substrate is prepared (FIG. 4A). ). Next, the first conductive layer 15 and the second conductive layer 16 are selectively removed by etching or the like to form wiring (FIG. 4B).

Next, the substrate 14 is selectively removed to form the blind via hole 18. The blind via hole 18 has the second conductive layer 16 as the bottom surface, and the substrate 14 and the first conductive layer 15 as the wall surface. In addition, the conductive paste 19 is applied to the formed blind via hole. As shown in FIG. 4D, the conductive paste is applied to the surface of the first conductive layer 15, which is the outer circumference of the blind via hole 18, and to the bottom surface of the blind via hole. Thereafter, the conductive paste 19 is heated and cured as necessary. You may harden | cure while pressing an electroconductive paste. By the above process, the 1st conductive layer 15 and the 2nd conductive layer 16 are electrically connected.

Since the conductive paste is also applied to the surface of the first conductive layer 15, which is the outer circumference of the blind via hole, not only the wall surface of the blind via hole but also the surface of the first conductive layer 15 is connected to the second conductive layer 16. do. Therefore, the conductivity of the blind via hole is improved, and a multilayer printed wiring board excellent in connection reliability can be obtained. In addition, a process such as bonding or peeling of the release film is not required, and a multilayer printed wiring board can be manufactured by a simple process.

In addition, since the via via hole 18 can be formed after the wiring of the first conductive layer 15 and the second conductive layer 16 is formed, the first conductive layer 15 and the second conductive layer 16 are formed. Can be simultaneously etched to form wiring. In addition, by forming wiring in advance, it is also possible to collectively stack a substrate coated with the conductive paste shown in FIG. 4D and another substrate to manufacture a multilayer printed wiring board having three or more conductive layers. A multilayer printed wiring board means the printed wiring board with two or more conductive layers, and shall also include a double-sided board.

Invention of Claim 2 is a manufacturing method of the multilayer printed wiring board of Claim 1 whose diameter of the said blind via hole is 30 micrometers or more and 200 micrometers or less. By making the diameter of the said blind via hole into 30 micrometers or more and 200 micrometers or less, connection reliability and high density packageability can be made compatible. The shape of the blind via hole can be any shape, such as a circle or an ellipse, and in the case of shapes other than a circle, the maximum length of the opening is the diameter of the blind via hole.

Invention of Claim 3 is apply | coated so that application | coating of the said electrically conductive paste may coat | cover the whole outer periphery of the said blind via hole, It is the manufacturing method of the multilayer printed wiring board of Claim 1 or 2 characterized by the above-mentioned. By applying a conductive paste so as to cover the entire outer circumference of the blind via hole, the first conductive layer 15 and the second conductive layer 16 can be satisfactorily connected, and a multilayer printed wiring board excellent in connection reliability can be obtained.

In the invention according to claim 4, the difference between A and B is 20 µm or more and 200 µm or less when the coating diameter of the conductive paste is set to A and the diameter of the blind via hole is set to B. It is a manufacturing method of a multilayer printed wiring board. Thus, by apply | coating an electrically conductive paste, connection reliability and high density wiring can be made compatible. The application shape of the conductive paste can be any shape such as a circle or an ellipse, and in the case of shapes other than the circle, the maximum length of the application portion is the application diameter of the conductive paste.

The invention according to claim 5 further includes a step of laminating an insulating layer covering at least one surface of the double-sided substrate, and after the step of applying the conductive paste, the insulating layer is laminated and then pressed to insulate It is a manufacturing method of the multilayer printed wiring board as described in any one of Claims 1-4 characterized by bonding a layer to the said double-sided wiring board.

FIG. 5 is a flowchart showing an example of a method of manufacturing the multilayer printed wiring board of the invention according to claim 5. FIG. An insulating layer (coverlay film) 22 having an insulating base 20 and an adhesive layer 21 is laminated on a double-sided substrate 17 coated with a conductive paste (FIG. 5A). If necessary, the conductive paste is previously heated and dried before lamination. Thereafter, when the laminate of the insulating layer and the double-sided substrate is pressed, the insulating layer is adhered to the double-sided substrate 17 by the adhesive layer 21. Pressing is often performed under heating conditions, and this step can perform thermosetting of the conductive paste and adhesion of the insulating layer at once. Therefore, the manufacturing method of the multilayer printed wiring board which is excellent in productivity can be provided. The insulating layer (coverlay film) may be laminated on the opposite side of the double-sided substrate 17 (side covering the second conductive layer 16), or may be laminated on both surfaces and pressed simultaneously. In this case, productivity is further improved.

Invention of Claim 6 has a base material, the 1st conductive layer formed on one surface of the said base material, and the 2nd conductive layer formed on the other surface of the said base material, The said 1st conductive layer and the said 2nd conductive layer are A multilayer printed wiring board electrically connected to a cured product of an electrically conductive paste, the multilayer printed wiring board having a blind via hole having the second conductive layer as a bottom surface, and having the base material and the first conductive layer as a wall surface, and an outer periphery of the blind via hole. It is a multilayer printed wiring board coat | covered with the hardened | cured material of an electrically conductive paste so that it may continue to the surface of a 1st conductive layer which is a phosphorus, and the bottom surface of the said blind via hole. Since the first conductive layer, which is the outer circumference of the blind via hole, is covered with a cured product of the conductive paste so as to be continuous to the bottom surface of the blind via hole, the first conductive layer and the second conductive layer are connected satisfactorily, and thus connection reliability is achieved. This excellent multilayer printed wiring board can be obtained.

(Effects of the Invention)

This invention provides the manufacturing method of the high productivity multilayer printed wiring board which can manufacture the multilayer printed wiring board which is excellent in connection reliability by a simple process. Moreover, the multilayer printed wiring board which is excellent in connection reliability is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows the manufacturing process of the conventional multilayer printed wiring board.

2 is a schematic cross-sectional view showing a step of manufacturing a conventional multilayer printed wiring board.

It is a cross-sectional schematic diagram which shows the manufacturing process of the conventional multilayer printed wiring board.

It is a cross-sectional schematic diagram which shows the manufacturing process of the multilayer printed wiring board of this invention.

It is a cross-sectional schematic diagram which shows the manufacturing process of the multilayer printed wiring board of this invention.

(Explanation of the sign)

1: Insulating base material 2: Wiring layer

3: single-sided copper foil adhesive base material 4: peeling film

5: blind via hole 6: conductive paste

7: metal film 8: base material

9: first metal layer 10: second metal layer

11 substrate 12 hole

13 metal 14 base material

15: first conductive layer 16: second conductive layer

17: double-sided substrate 18: blind via hole

19: conductive paste 20: insulating base

21: adhesive layer 22: insulating layer (coverlay film)

(The best mode for carrying out the invention)

The present invention is described in detail below. An insulating resin film can be used as a base material used for this invention, Polyethylene terephthalate, a polyimide, etc. are illustrated. In consideration of heat resistance, a resin film mainly containing polyimide is preferable. The thickness of a base material can be suitably selected according to the use of a multilayer printed wiring board, and generally the thing of about 5 micrometers-50 micrometers is used.

Metal foil can be used as a 1st conductive layer and a 2nd conductive layer. In consideration of conductivity and durability, a metal foil mainly containing copper is preferable, and copper or an alloy mainly containing copper is exemplified. In addition to copper, you may use silver, aluminum, nickel, etc. The thickness of a conductive layer can be suitably selected according to the use of a multilayer printed wiring board, and generally 5 micrometers-about 50 micrometers are used. The conductive layer and the substrate are bonded directly or through an adhesive. You may use the commercially available double-sided copper adhesion board which copper foil was bonded to both surfaces of the polyimide resin film.

The first conductive layer and the second conductive layer are selectively removed by etching or the like to form wiring. In etching, after forming a wiring pattern such as a resist layer on the conductive layer, the chemical etching is performed by immersing the conductive layer in an etchant that erodes the conductive layer to remove portions other than the wiring pattern, and then removing the resist layer. (Erosion etching) is illustrated. When the first conductive layer and the second conductive layer are etched simultaneously, the etching step can be performed once, and the manufacturing cost can be reduced.

The substrate or the substrate and the first conductive layer are selectively removed from the wiring-formed double-sided substrate by a method such as laser processing to form blind via holes. Laser machining, it is possible to use a laser, such as UV-YAG laser, CO ₂ laser, it is also possible to form a blind via hole with a method other than laser processing. It is preferable that the diameter of a blind via hole is 30 micrometers-200 micrometers. When diameter is smaller than 30 micrometers, connection area will become small and the connection resistance of a 1st conductive layer and a 2nd conductive layer will become large. If the diameter is larger than 200 mu m, the via hole becomes larger than the wiring width, and high density mounting cannot be performed. More preferred blind via holes have a diameter of 50 µm to 150 µm.

Smear removal after laser processing uses wet desmear by alkali and potassium permanganate, a blast process, the wet blast process which disperse | distributes an inorganic particle in a liquid, a plasma process, etc. are used.

The electrically conductive paste used for this invention disperse | distributes electroconductive fillers, such as metal powder, in binder resin. Platinum, gold, silver, copper, palladium, and the like are exemplified as the metal type, and among them, silver powder or silver-coated copper powder is particularly preferable because of excellent conductivity.

As the binder resin, an epoxy resin, a phenol resin, a polyester resin, a polyurethane resin, an acrylic resin, a melamine resin, a polyimide resin, a polyamideimide resin, or the like can be used. In consideration of the heat resistance of the conductive paste, it is preferable to use a thermosetting resin, and it is particularly preferable to use an epoxy resin. Although the kind of epoxy resin is not specifically limited, Naphthalene type epoxy resin, a novolak-type epoxy resin, a biphenyl type epoxy resin, dicyclopenta other than bisphenol type epoxy resin etc. which make bisphenol A, F, S, AD etc. frame | skeleton Diene type epoxy resin etc. are illustrated. Moreover, the phenoxy resin which is a high molecular weight epoxy resin can also be used.

The binder resin can be dissolved and used in a solvent, and organic solvents such as esters, ethers, ketones, ether esters, alcohols, hydrocarbons, and amines can be used as the solvent. Since the conductive paste is filled into the blind via hole by a method such as screen printing, a high boiling point solvent excellent in printability is preferable, and carbitol acetate, butyl carbitol acetate, and the like are particularly preferable. It is also possible to use a combination of several kinds of these solvents. These materials are mixed and dispersed with three rolls, a rotary stirring defoaming machine, etc., to make a uniform state, and an electrically conductive paste is produced.

The conductive paste is applied by a method such as screen printing to fill the blind via hole with the conductive paste. When the conductive paste is applied continuously to the surface of the first conductive layer, which is the outer circumference of the blind via hole, and the bottom surface of the blind via hole, the first conductive layer and the second conductive layer are electrically connected through the conductive paste. It is preferable that the conductive paste covers both the outer circumference and the bottom surface of the blind via hole, but may be partially lacking if it can be electrically connected.

When the conductive paste is applied so as to cover the entire outer circumference of the blind via hole, the connection reliability is high, which is preferable. Moreover, when the application diameter of an electrically conductive paste is set to A, and the diameter of the said blind via hole is set to B, it is preferable that the difference of A and B shall be 20 micrometers or more and 200 micrometers or less. When the coating diameter of an electrically conductive paste is smaller than this value, the connection resistance of a 1st conductive layer and a 2nd conductive layer will become high, and connection reliability will become low. Moreover, when the coating diameter of an electrically conductive paste is larger than this value, a connection part will become large compared with wiring and it is difficult to carry out high density mounting. In addition, when the conductive paste is applied so as to fill the entire inside of the blind via hole, the connection resistance between the first conductive layer and the second conductive layer can be lowered.

It is preferable to predry the apply | coated electrically conductive paste and to remove the solvent contained in an electrically conductive paste. By removing the residual solvent in the conductive paste, the generation of voids in the blind via hole can be prevented, and the connection resistance value can be made low. Moreover, if preliminary drying is performed in a reduced pressure atmosphere, a solvent can be removed efficiently even if the predrying temperature is low, and the hardening reaction of the binder resin during predrying can be suppressed.

Thereafter, the conductive paste is cured. Although hardening of an electrically conductive paste is common in thermosetting, it can also be performed by methods, such as an ultraviolet curing. Moreover, in the case of the electrically conductive paste which made thermoplastic resin the binder resin, although the paste solidifies only by drying a solvent, this also calls hardened | cured material of an electrically conductive paste in this invention.

When the conductive paste is cured while pressing, the conductivity is improved, which is preferable. By pressing, the electrically conductive paste is compressed, and the connection resistance between a 1st conductive layer and a 2nd conductive layer becomes small. The compressed conductive paste is also filled in the blind via holes.

When only the double-sided board | substrate which apply | coated the electrically conductive paste is pressed, the multilayer printed wiring board which the 1st conductive layer and the 2nd conductive layer connected through the blind via hole can be obtained. This wiring board and another wiring board can be laminated | stacked, and the multilayer printed wiring board which has three or more wiring layers can also be created. Moreover, an insulating layer (coverlay film) can be laminated | stacked on one side or both sides of the double-sided board | substrate which apply | coated the conductive paste, and adhesion of a coverlay film and press of a conductive paste can also be performed at once.

It is preferable to perform a press under heating. Moreover, when it heat-presses in a vacuum state, the void generation in an electrically conductive paste can be prevented, and it is more preferable. Although heating temperature can be suitably selected according to the kind of electroconductive paste, it is 100 degreeC-280 degreeC normally.

Example

Next, an invention is demonstrated based on an Example. However, the scope of the present invention is not limited only to an Example.

(Example 1)

A double-sided copper adhesive substrate (polyimide film thickness: 25 µm, copper foil thickness: 12 µm) was prepared by bonding copper foil to both surfaces of the polyimide film without using an adhesive, and the copper foils on both sides were etched and wired. Formed. Furthermore, the blind via hole (opening diameter 100 micrometers) which has a bottom was formed by UV-YAG laser, and the wet blasting process was performed. 1296 blind via holes were formed.

70 mass parts of bisphenol A-type epoxy resins (epoxy equivalent 7000-885), and 30 mass parts of bisphenol F-type epoxy resins (epoxy equivalent 160-170) were melt | dissolved in butyl carbitol acetate. 12 mass parts of imidazole series latent hardening | curing agents were added here, and also silver particle was added so that it might become 55 volume% of all solid content, and the electrically conductive paste was produced.

The conductive paste was filled in each blind via hole by screen printing. The electrically conductive paste was apply | coated so that the whole blind via hole might be coat | covered, and application | coating diameter was 150 micrometers. Thereafter, the mixture was heated to 70 ° C. under reduced pressure (1.3 kPa or less), preliminarily dried to remove the solvent in the conductive paste.

The double-sided board | substrate which apply | coated the electrically conductive paste was vacuum-pressed, and the multilayer printed wiring board which 1296 via holes were connected by the daisy chain structure was produced. Press conditions are the temperature of 200 degreeC, and pressure 2.0MPa.

(Example 2)

The same conditions as in Example 1 except that a coverlay film (a polyimide film having a thickness of 12 µm in which an adhesive layer having a thickness of 20 µm was laminated on one side) was laminated on both surfaces of the double-sided substrate coated with the conductive paste, and subjected to a vacuum press. As a result, a multilayer printed wiring board in which 1296 via holes were connected in a daisy chain structure was produced.

(Example 3)

On both sides of the double-sided substrate to which the conductive paste was applied, a coverlay film (polyimide film having a thickness of 12 μm in which an adhesive layer having a thickness of 20 μm was laminated on one side) was laminated, and the coating diameter of the conductive paste was set to 100 μm and vacuumed. A multilayered printed circuit board was fabricated in which 1296 via holes were connected in a daisy chain structure on the same conditions as in Example 1 except that pressing was performed.

(Example 4)

A coverlay film (12 μm thick polyimide film having an adhesive layer having a thickness of 20 μm laminated on one side) was laminated on both surfaces of the double-sided substrate on which the conductive paste was applied, and the vacuum paste was pressed at a coating diameter of 350 μm. A multilayer printed wiring board was produced in which 1296 via holes were connected in a daisy chain structure, except that the following conditions were carried out.

(Evaluation of connection resistance)

Connection resistance was measured about the obtained multilayer printed wiring board. The measurement was performed by measuring resistance by the 4-terminal method from both ends of a daisy chain. The resistance value is considered to be the sum of the resistance of the conductive paste filled in 1296 via holes, the resistance of the conductive layer, and the contact resistance of the conductive paste and the conductive layer.

(Reliability assessment)

Furthermore, after passing the multilayer printed wiring board through the reflow furnace of the peak temperature of 260 degreeC 6 times, connection resistance was measured and the resistance increase rate was calculated | required.

Connection resistance (Ω) Early After reflow Ascent Example 1 20.4Ω 20.4Ω 0% Example 2 20.6Ω 20.6Ω 0% Example 3 24.0Ω 25.2Ω 5% Example 4 22.8Ω 23.2Ω 2%

As can be seen from Table 1, it can be seen that the multilayer printed wiring boards of Examples 1 to 4 have a low resistance increase rate after reflow of 5% or less, which is excellent in connection reliability.

Claims (6)

Preparing a double-sided substrate having a substrate, a first conductive layer formed on one surface of the substrate, and a second conductive layer formed on the other surface of the substrate, Selectively removing the first conductive layer and the second conductive layer to form wiring; Selectively removing the substrate to form a blind via hole having the second conductive layer as a bottom surface and the substrate and the first conductive layer as a wall surface; and Applying a conductive paste to the surface of the first conductive layer, which is the outer circumference of the blind via hole, and the bottom surface of the blind via hole, And a first conductive layer and a second conductive layer electrically connected to each other. The method of claim 1, The blind via hole has a diameter of 30 µm or more and 200 µm or less. The method according to claim 1 or 2, Coating of the said conductive paste is apply | coated so that the outer periphery of the said blind via hole may be coat | covered, The manufacturing method of the multilayer printed wiring board characterized by the above-mentioned. The method of claim 3, When the coating diameter of the said conductive paste is set to A and the diameter of the said blind via hole is set to B, the difference of A and B is 20 micrometers or more and 200 micrometers or less, The manufacturing method of the multilayer printed wiring board characterized by the above-mentioned. The method according to any one of claims 1 to 4, Laminating an insulating layer covering at least one surface of the double-sided substrate, After the process of apply | coating the said conductive paste, the said insulating layer is laminated | stacked, it presses, and the said insulating layer is adhere | attached on a double-sided wiring board, The manufacturing method of the multilayer printed wiring board characterized by the above-mentioned. A base material, the 1st conductive layer formed on one surface of the said base material, and the 2nd conductive layer formed on the other surface of the said base material, The said 1st conductive layer and the said 2nd conductive layer are the hardened | cured material of an electrically conductive paste. As a multilayer printed wiring board electrically connected, And a blind via hole having the second conductive layer as a bottom surface and the substrate and the first conductive layer as a wall surface. A cured product of a conductive paste is formed on the surface of the first conductive layer, which is the outer circumference of the blind via hole, and the bottom surface of the blind via hole.

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