KR101518067B1 - Multilayer printed wiring board and its manufacturing method - Google Patents

Abstract

A multilayer printed wiring board and a manufacturing method that can improve the degree of freedom of design are provided. A first connecting portion is formed in which the second connecting portion formed on the second conductor wiring of the flexible printed wiring board is connected to the first conductor wiring other than the outermost layer of the plurality of first conductor wirings of the multilayer rigid printed wiring board. Then, the first connecting portion is drawn out from the multilayer rigid printed wiring board main body.

Description

[0001] MULTILAYER PRINTED WIRING BOARD AND ITS MANUFACTURING METHOD [0002]

The present invention relates to a multilayer printed circuit board used as a component of an electronic apparatus and a method of manufacturing the same.

In recent years, in the field of electronic devices, a printed wiring board used as a component of electronic equipment has become more multilayered with the increase in the density of electronic devices. As such a multilayer printed wiring board, a flexible printed wiring board having a multilayer structure, And a flexible rigid printed wiring board which is a composite substrate of a printed wiring board.

As a connection structure of the multilayer printed wiring board, a structure is known in which a rigid printed wiring board and a flexible printed wiring board are connected using an anisotropic conductive adhesive. More specifically, a conductor wiring of a multi-layer rigid printed wiring board in which a wiring substrate such as a glass substrate is provided in multiple layers with an insulating layer sandwiched therebetween and a conductor wiring of a flexible printed wiring board are electrically connected with an anisotropic conductive adhesive interposed therebetween , And a flexible printed wiring board is laminated and connected to a multilayer rigid printed wiring board (see, for example, Japanese Patent Application Laid-Open No. 8-15716).

However, in the connection structure described in Japanese Patent Application Laid-Open No. 8-15716, since the anisotropic conductive adhesive is hardened by heating and pressing, the conductor wirings are connected. Therefore, in the multilayer rigid printed wiring board, (I.e., degree of freedom of wiring) is lowered due to the necessity of providing it on the outer layer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a multilayer printed wiring board and a manufacturing method thereof that can improve the degree of freedom of design.

In order to achieve the above object, the first invention of the present application is a multilayer printed wiring board comprising a multilayer wiring board having a plurality of first conductor wirings and a flexible printed wiring board having a second conductor wiring connected to the first conductor wirings, , A first connecting portion is formed in which a second connecting portion formed on the second conductor wiring of the flexible printed wiring board is connected to the first conductor wiring other than the outermost layer of the plurality of first conductor wirings, And the wiring board is extended outward from the main body of the multilayer wiring board.

According to the above configuration, since the first connecting portion is formed on any of the first conductor wirings other than the outermost layer, to which the second connecting portion formed on the second conductor wiring of the flexible printed wiring board is connected, Unlike the connection structure, there is no need to provide the connection portion in the outermost layer. Therefore, the degree of freedom in designing (i.e., the degree of freedom of wiring) of the multilayered printed circuit board can be improved.

The second invention of the present application is a multilayer printed wiring board according to the first invention of the present application, wherein the multilayer wiring board is a multilayer rigid printed wiring board obtained by laminating a plurality of rigid printed wiring boards. According to the above configuration, since the multilayer wiring board is constituted only by the rigid printed wiring board, the dimensional stability of the multilayer wiring board is improved and it is possible to cope with high precision.

The third invention of the present application is the multilayer printed wiring board according to the first invention or the second invention of the present application, wherein the outermost layer of the plurality of first conductor wires is a shield layer.

According to the above structure, since the first conductor wiring in the outermost layer in which the first connecting portion is not formed can be provided as the shielding layer, the electromagnetic shielding effect of the multilayer printed wiring board can be improved while improving the degree of freedom in designing.

The fourth invention of the present application is a multilayer printed wiring board according to any one of the first to third inventions of the present application, wherein the first connecting portion and the second connecting portion are connected via an anisotropic conductive adhesive containing conductive particles .

According to the above configuration, since the first and second connection portions can be connected by a low conductive resistance, the conductivity between the first and second connection portions can be improved.

The fifth invention of the present application provides a method for manufacturing a multilayer wiring board, comprising the steps of: laminating a printed wiring board on which a slit is formed and another printed wiring board to produce a multilayer wiring board having a plurality of first conductor wirings; The step of exposing the first connecting portion formed on the first conductor wiring other than the outermost layer of the first conductor wiring of the layer to the outside and pulling out the first connecting portion outward from the main body of the multilayer wiring board, And a step of connecting a second connecting portion formed in the second conductor wiring of the flexible printed wiring board.

According to the above configuration, since the first connecting portion connected to the second connecting portion formed on the second conductor wiring of the flexible printed wiring board is formed on any first conductor wiring other than the outermost layer, A multilayered printed circuit board in which the connecting portion is not provided on the outermost layer can be provided. Therefore, the degree of freedom in designing (i.e., the degree of freedom of wiring) of the multilayered printed circuit board can be improved.

According to the present invention, it is possible to improve the degree of freedom (that is, the degree of freedom of wiring) of the multilayer printed wiring board.

Hereinafter, preferred embodiments of the present invention will be described. 1 (a) to 1 (d) are diagrams for explaining a method of manufacturing a rigid printed wiring board constituting the multilayered printed wiring board of the present invention, and Fig. 2 is a cross-sectional view of a rigid printed wiring board constituting a multilayered printed wiring board of the present invention Fig. Fig. 3 is a cross-sectional view showing a flexible printed wiring board constituting the multilayered printed wiring board according to the present invention. Figs. 4 (a) to 4 (d) illustrate a method of manufacturing a multilayered printed wiring board according to an embodiment of the present invention Fig. 5A to 5D are cross-sectional views for explaining a method of manufacturing a multilayered printed circuit board according to an embodiment of the present invention, in which the subsequent steps of FIGS. 4A to 4D are referred to as " Fig. In the present embodiment, as the multilayer printed wiring board, a flexible printed wiring board having a multilayered rigid printed wiring board as a multilayer wiring board having a plurality of first conductor wirings and a second conductor wiring connected to the first conductor wiring is connected Is explained as an example.

As a method of manufacturing the multilayered printed circuit board according to the present embodiment, first, a rigid printed wiring board 6 is manufactured as shown in Figs. 1 (a) to 1 (d). More specifically, as shown in Fig. 1A, a first conductor wiring (or conductor circuit) 3 (for example, a conductor circuit) 3 made of a metal foil is formed on both surfaces of a substrate 2 (a glass substrate or a glass epoxy substrate, ) Are provided on the wiring board 4. As the metal foil constituting the first conductor wiring 3, a copper foil is preferably used.

Next, as shown in Fig. 1 (b), the unnecessary portion of the first conductor wiring 3 is removed by etching by a conventional method, and the first conductor 3 having a predetermined pattern shown in Fig. 1 (b) Thereby forming a wiring 3.

Next, as shown in Fig. 1 (c), a rigid printed wiring board 6 is produced by providing a shoulder resist 5 as an insulating layer on the surface of the first conductor wiring 3. As the resin constituting the shoulder resist 5, a resin material which is inexpensive and versatile can be used. For example, an acrylic resin, an epoxy resin, a urethane resin or a silicone resin can be used.

Next, as shown in Fig. 1 (d), the rigid printed wiring board 6 is formed into a slit shape using a cutting tooth form (for example, a blade type in which a Thompson blade is arranged) (7). Through the above steps, the rigid printed wiring board 6 used in the multilayered printed circuit board of the present embodiment is manufactured.

2, in the rigid printed wiring board 8 laminated with the rigid printed wiring board 6, the first conductor wiring 3 made of a metal foil is provided on both surfaces of the base material 2, The first conductor wiring 3 is formed on the rigid printed wiring board 8 in such a manner that the slit 7 is not formed on the rigid printed wiring board 8 and the first conductor wiring 3 is provided on the flexible printed wiring board 10 Except that the shoulder resist 5 is not formed and the first connection portion 9 is exposed to the outside so as to be electrically connected to the two-conductor wiring 12 (see FIG. 3 to be described later).

As shown in Fig. 3, the flexible printed wiring board 10 is a so-called double-sided flexible printed wiring board (first printed wiring board) in which two second conductor wirings 12 are provided on each of both surfaces of a substrate 11 formed of a flexible resin film. And a coverlay film 13 which is an insulating layer is provided so as to cover the second conductor wiring 12. 3, the second conductor wiring 12 is electrically connected to the first conductor wiring 3 provided on the above-described rigid printed wiring board 8, so as to be electrically connected to the flexible printed wiring board 10, A second connecting portion 14 is formed which is exposed to the outside without forming the ray film 13.

3, the coverlay film 13 includes an adhesive layer 15 laminated on the second conductor wiring 12 so as to cover the second conductor wiring 12, And a film (16).

As the resin film constituting the base material 11, a resin material excellent in flexibility is used. As such a resin film, for example, a film of a general-purpose resin for a flexible printed circuit board such as a polyester film can be used. In addition, it is particularly preferable to have high heat resistance in addition to flexibility. Examples of such a resin film include polyamide-based resin films, polyimide-based resin films such as polyimide and polyamideimide, polyethylene naphthalate Is preferably used. As the metal foil constituting the second conductor wiring 12, a copper foil is preferably used.

As the resin film 16, the same resin film as the resin film constituting the base material 11 described above can be used. The adhesive constituting the adhesive layer 15 is preferably excellent in flexibility and heat resistance. Examples of such adhesives include adhesives of various resins such as nylon, epoxy resin, butyral resin and acrylic resin .

Next, a method of manufacturing a multilayer printed wiring board using the rigid printed wiring boards 6 and 8 and the flexible printed wiring board 10 will be described.

First, as shown in Fig. 4 (a), the prepared rigid printed wiring board 6 and the rigid printed wiring board 8 provided with the first connecting portion 9 are faced so as to face the shoulder resist 5, The adhesive layer 17 is sandwiched between the rigid printed wiring boards 6 and 8. [ The adhesive constituting the adhesive layer 17 is preferably excellent in flexibility and heat resistance. Examples of such adhesives include adhesives of various resins such as nylon, epoxy resin, butyral resin, and acrylic resin . A ceramic filler or a rubber filler may be dispersed in these adhesive resins. Subsequently, the two rigid printed wiring boards 6 and 8 are bonded to each other through the adhesive layer 17 by heating and pressing, and the rigid printed wiring boards 6 and 8 ) Are stacked in this order to form a multilayer body (18). In the present embodiment, the two rigid printed wiring boards 6 and 8 are laminated. Alternatively, three or more rigid printed wiring boards may be laminated and provided in multiple layers.

In this embodiment, the outermost layer of the first conductor wirings 3 (that is, the first conductor wirings 3 as the lowermost layer in Fig. 4 (a)) is used as the shield layer And the first conductor wiring 3 in the outermost layer on which the first connecting portion 9 is not formed is provided as a shield layer.

That is, in the above-described conventional multi-layered rigid printed wiring board, it is difficult to provide the shielding layer on the outermost layer because it is necessary to provide the connection portion in the outermost layer as described above. However, in this embodiment, A first connecting portion 14 connected to the second connecting portion 14 formed on the second conductor wiring 12 of the flexible printed wiring board 10 is connected to the first conductor wiring 3 other than the outermost layer of the one- 9, the first conductor wiring 3 in the outermost layer can be used as a shield layer.

As shown in Fig. 4 (a), when the adhesive layer 17 is sandwiched between the rigid printed wiring boards 6 and 8, the planar direction of the rigid printed wiring boards 6, 8 The end portion 17a of the adhesive layer 17 is disposed outside the slit 7 formed in the rigid printed wiring board 6. In this case, With this configuration, when the rigid printed wiring boards 6 and 8 are laminated, a part of the rigid printed wiring board 6 on which the slit 7 is formed (that is, the portion of the rigid printed wiring board 6 outside the slit 7 in the planar direction X) (6a) can be prevented from being separated.

Next, as shown in Fig. 4 (b), a via hole 19 is formed on the substrate 2 of the rigid printed wiring board 6 on which the slits 7 are formed by using a CO ₂ laser, a YAG laser or the like. Then, as shown in Fig. 4 (c), the through hole 20 is formed in the layered product 18 by NC (Numerical Control) punching.

4 (d), electroless copper plating (chemical copper plating) is performed on the via hole 19 and the through hole 20, and then electrolytic copper plating is performed using a copper sulfate solution or the like. As a result, Copper plating 21 is provided on the surface of the first conductor wiring 19, the surface of the through hole 20, and the surface of the first conductor wiring 3.

Next, as shown in Fig. 5A, the rigid printed wiring board 6 on which the slits 7 are formed is etched by a conventional method to remove unnecessary portions of the first conductor wirings 3, Thereby forming a first conductor wiring 3 having a pattern.

Next, as shown in Fig. 5 (b), a plurality of first conductor wirings 3 can be formed by providing a shoulder resist 22 as an insulating layer on the surface of the copper plating 21 of the layered body 18 Layered rigid printed wiring board 23 is produced. As the resin constituting the shoulder resists 22, resins similar to those of the shoulder resists 5 described above can be used.

5 (c), a part 6a of the rigid printed wiring board 6 is removed through the slit 7 in the rigid printed wiring board 6 having the slits 7 formed thereon, The first connecting portion 9 formed on the rigid printed wiring board 8 is exposed to the outside and the first connecting portion 9 is formed in the plane direction of the multilayered rigid printed wiring board 23 Is pulled out from the multilayer rigid printed wiring board main body 23a. That is, in the multilayer rigid printed wiring board 23, the first conductor wiring 3 other than the outermost layer of the plurality of first conductor wirings 3 is connected to the flexible printed wiring board 10 1 connecting portion 9, it is not necessary to provide the connecting portion in the outermost layer unlike the conventional connecting structure of the multilayer printed wiring board.

In the present embodiment, a multilayer rigid printed wiring board 23 in which a plurality of rigid printed wiring boards 6 and 8 are laminated is used as a multilayer wiring board. Therefore, since the multilayered wiring board is constituted only by the rigid printed wiring boards 6 and 8, the dimensional stability of the multilayered wiring board is improved, and it is possible to cope with high precision.

That is, in general, in a multilayered wiring board in which a rigid printed wiring board and a flexible printed wiring board are laminated, the flexible printed wiring board is deformed by thermal expansion or heat shrinkage by the heating and pressing treatment at the time of laminating the rigid printed wiring board and the flexible printed wiring board Therefore, there has been a problem that it becomes difficult to manage the dimension, and it becomes impossible to cope with high precision.

On the other hand, in the present embodiment, since the multilayer wiring board is constituted only by the rigid printed wiring boards 6 and 8, even when the heating and pressurizing processing is performed when the plural rigid printed wiring boards 6 and 8 are laminated, It is possible to suppress the deformation of the rigid printed wiring boards 6 and 8 due to the stress applied to the printed wiring boards 6 and 8 so that the dimensional stability of the multilayered wiring board is improved and it is possible to cope with high precision.

Then, as shown in Fig. 5 (d), the anisotropic conductive adhesive 24 is cured by applying heat and pressure treatment through the anisotropic conductive adhesive 24 to form the multilayer rigid printed wiring board 23 and the flexible printed wiring board 10).

More specifically, for example, an anisotropically conductive adhesive 24 mainly composed of a thermosetting resin such as epoxy resin is mounted on the first connecting portion 9 formed on the rigid printed wiring board 8, and the direction of the rigid printed wiring board 8 The anisotropic conductive adhesive agent 24 is bonded to the first connecting portion 9 and the anisotropic conductive adhesive agent 24 is adhered to the rigid printed wiring board 8 by a predetermined pressure.

Next, the first conductor wirings 3 formed on the rigid printed wiring board 8 and the second conductor wirings 12 formed on the flexible printed wiring board 10 are connected to each other with the flexible printed wiring board 10 facing downward The rigid printed wiring board 8 and the flexible printed wiring board 10 are aligned with each other so that the anisotropic conductive adhesive 24 is interposed between the rigid printed wiring board 8 and the flexible printed wiring board 10. [

Next, the second connection portion 14 provided on the flexible printed wiring board 10 is mounted on the anisotropic conductive adhesive 24. The anisotropically conductive adhesive 24 is pressed in the direction of the rigid printed wiring board 8 at a predetermined pressure through the flexible printed wiring board 10 in a state where the anisotropically conductive adhesive 24 is heated to a predetermined curing temperature, Whereby the anisotropic conductive adhesive 24 is heated and melted. Further, as described above, since the anisotropic conductive adhesive 24 contains a thermosetting resin as a main component, the adhesive is once softened by heating at the above-mentioned curing temperature, but is hardened by continuing the heating. When the preset curing time of the anisotropic conductive adhesive 24 has elapsed, the holding state of the curing temperature of the anisotropic conductive adhesive 24 is released and cooling is started, And the conductor wirings 3 and the second conductor wirings 12 are connected. With the above connection method, the multilayered printed circuit board 30 according to the present embodiment can be manufactured.

In the present embodiment, the anisotropic conductive adhesive 24 includes conductive particles. For example, conductive particles are dispersed in a resin film containing an insulating thermosetting resin such as an epoxy resin as a main component Can be used.

When an epoxy resin is used as the thermosetting resin, for example, an epoxy resin of bisphenol A type, F type, S type, AD type, copolymer of bisphenol A type and bisphenol F type, naphthalene type epoxy resin, Type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin and the like can be used. A phenoxy resin which is a high molecular weight epoxy resin may also be used.

As the anisotropically conductive adhesive 24, for example, there may be used a resin film mainly composed of the above-described epoxy resin, in which a plurality of fine metal particles (for example, metal fine particles made of spherical metal fine particles or metal spherical resin particles plated with metal) , A shape connected to a straight chain shape, or a shape having a needle shape, and a metal powder having a shape of a so-called aspect ratio is dispersed. The aspect ratio referred to herein means the ratio of the minor axis diameter (length of the cross section of the conductive particles) and the major axis diameter (length of the conductive particles) of the conductive particles.

In the present embodiment, it is preferable that the aspect ratio of the conductive particles is 5 or more. By using such conductive particles, the probability of contact between the conductive particles increases when the anisotropic conductive adhesive 24 is used. Therefore, the first conductor wiring 3 and the second conductor wiring 12 can be electrically connected without increasing the amount of the conductive particles.

The metal powder to be used in the present invention may preferably include a ferromagnetic substance in a part thereof, and may be a metal having ferromagnetic property, two or more kinds of alloys having ferromagnetic property, an alloy of a ferromagnetic metal and another metal, Or a complex containing at least one of the foregoing. This is because, by using a metal having ferromagnetism, it is possible to orient the conductive particles using the magnetic field by the magnetic property of the metal itself. For example, nickel, iron, cobalt, and two or more kinds of alloys including these.

The aspect ratio of the conductive particles is directly measured by a method such as a CCD microscope observation. In the case of conductive particles whose cross section is not a circle, the aspect ratio is obtained by setting the maximum length of the cross section to the minor axis diameter. The conductive particles do not necessarily need to have a straight shape, and can be used without problems even if there is some warp or crack. In this case, the aspect ratio is determined with the maximum length of the conductive particles as the major axis diameter.

According to the present embodiment described above, the following effects can be obtained.

(1) In this embodiment, the first conductor wirings 3 other than the outermost layer of the multiple first conductor wirings 3 of the multilayered rigid printed wiring board 23 are provided with the And the first connecting portion 9 to which the second connecting portion 14 formed on the second conductor wiring 12 is connected. The first connection portion 9 is configured to extend outward from the multilayered rigid printed wiring board main body 23a. Therefore, since the first connecting portion 9 to which the second connecting portion 14 of the flexible printed wiring board 10 is connected is formed in any first conductor wiring 3 other than the outermost layer, Unlike the connection structure of the wiring board, there is no need to provide the connection portion in the outermost layer. Therefore, the degree of freedom in designing (i.e., the degree of freedom of wiring) of the multilayer printed wiring board 30 can be improved.

(2) In this embodiment, a multilayer rigid printed wiring board 23 in which a plurality of rigid printed wiring boards 6, 8 are laminated is used as a multilayer wiring board. Therefore, since the multilayered wiring board is constituted only by the rigid printed wiring boards 6 and 8, the dimensional stability of the multilayered wiring board is improved, and it is possible to cope with high precision.

(3) In this embodiment, the outermost layer of the plurality of first conductor wirings 3 is used as a shield layer. Therefore, since the first conductor wiring 3 in the outermost layer on which the first connecting portion 9 is not formed can be provided as a shield layer, the electromagnetic wave shielding effect of the multilayer printed wiring board 30 can be improved, Can be improved.

(4) In the present embodiment, the first connecting portion 9 and the second connecting portion 14 are connected via an anisotropic conductive adhesive 24 containing conductive particles. Therefore, since the first connection portion 9 and the second connection portion 14 can be connected by a low conductive resistance, the conductivity between the first connection portion 9 and the second connection portion 14 can be improved .

The present invention is not limited to the above-described embodiments, but various design changes can be made based on the object of the present invention, and they are not excluded from the scope of the present invention.

For example, in the above-described embodiment, a multilayered printed wiring board 23 in which a plurality of rigid printed wiring boards 6 and 8 are laminated is used as the multilayered wiring board. However, a multilayered printed wiring board 23 in which a plurality of flexible printed wiring boards A multilayer flexible printed wiring board or a flexible rigid printed wiring board which is a composite substrate of a flexible printed wiring board and a rigid printed wiring board may be used.

In the above-described embodiment, a so-called double-sided flexible printed wiring board in which two second conductor wirings 12 are provided on each of both surfaces of the substrate 11 is used. However, A single-sided flexible printed wiring board on which the second conductor wirings 12 are formed may be used.

The anisotropic conductive adhesive 24 is used to connect the first connecting portion 9 and the second connecting portion 14 to each other through the anisotropic conductive adhesive 24 containing the conductive particles. Alternatively, solder may be used. As the solder, for example, a solder paste containing 95 wt% or more of tin may be suitably used. In addition, it is preferable to use a solder paste not containing lead for environmental consideration.

The present invention relates to a multilayer printed circuit board used as a component of an electronic apparatus and a method of manufacturing the same.

1 (a) to 1 (d) are views for explaining a method of manufacturing a rigid printed wiring board constituting a multilayered printed circuit board of the present invention,

2 is a sectional view showing a rigid printed wiring board constituting a multilayered printed circuit board of the present invention,

3 is a cross-sectional view showing a flexible printed wiring board constituting the multilayered printed circuit board of the present invention,

4 (a) to 4 (d) are cross-sectional views for explaining a method of manufacturing a multilayer printed wiring board in an embodiment of the present invention,

5A to 5D are cross-sectional views for explaining a method for manufacturing a multilayered printed circuit board according to an embodiment of the present invention, in which the following steps of FIGS. 4A to 4D are explained For drawing.

DESCRIPTION OF THE REFERENCE NUMERALS

2, 11: substrate 3: first conductor wiring

4: wiring board 5: shoulder resist

6, 8: Rigid printed wiring board 7: Slit

9: first connection part 10: flexible printed wiring board

12: second conductor wiring 13: coverlay film

14: second connecting portion 17: adhesive layer

Claims (6)

A multilayer printed wiring board comprising a multilayer wiring board having a plurality of first conductor wirings and a flexible printed wiring board having a second conductor wirings connected to the first conductor wirings, Wherein the multilayer wiring board is a multilayer rigid printed wiring board in which a plurality of rigid printed wiring boards are laminated with an adhesive layer interposed therebetween, A first connecting portion to which a second connecting portion formed on the second conductor wiring of the flexible printed wiring board is connected is formed on the first conductor wiring other than the outermost layer of the first conductor wiring of the plurality of layers, The connecting portion is drawn out from the main body of the multilayer wiring board, Wherein the plurality of rigid printed wiring boards comprise a first rigid printed wiring board positioned above the adhesive layer with the adhesive layer interposed therebetween and a second rigid printed wiring board having the first conductor wirings located below the first rigid printed wiring board, / RTI > The end portion of the first rigid printed wiring board has a cross section of a slit formed using a blade type, Wherein the adhesive layer extends outward from the main body of the multilayer wiring board from the end face of the slit of the first rigid printed wiring board Wherein the multilayered printed circuit board is a multilayer printed circuit board. delete The method according to claim 1, Wherein the outermost layer of the plurality of first conductor interconnections is a shield layer. delete The method according to claim 1 or 3, Wherein the first connecting portion and the second connecting portion are connected via an anisotropic conductive adhesive containing conductive particles. A step of laminating a printed wiring board on which a slit is formed and another printed wiring board with an adhesive layer interposed therebetween to manufacture a multilayer wiring board having a plurality of first conductor wirings, A first connecting portion formed on the first conductor wiring other than the outermost layer of the first conductor wiring of the plurality of layers is exposed to the outside by removing a part of the printed wiring board through the slit, Outward from the main body of the wiring board, A step of connecting a second connecting portion formed in the second conductor wiring of the flexible printed wiring board to the first connecting portion At least, The slit is formed using a blade, Wherein the adhesive layer extends outward from the main body of the multilayer wiring board from the cross section of the slit of the printed wiring board Wherein the multilayered printed circuit board is manufactured by a method comprising the steps of:

Images