JP2015012097A - Manufacturing method of multilayer printed wiring board - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board capable of easily and reliably electrically connecting current-carrying portions of opposing substrates.
A printed wiring board manufacturing method according to the present invention includes a first substrate having a current-carrying part exposed on the front surface side, and a current-carrying part exposed on the back side of the first substrate facing the current-carrying part. A method of manufacturing a multilayer printed wiring board comprising a laminated second substrate, the step of forming a conductive portion made of a conductive paste on the surface of the conductive portion of the first substrate, the surface of the first substrate or the first substrate The step of laminating an adhesive around the current-carrying part in a plan view of the back surface of the two substrates, and the first substrate so that each current-carrying part facing the first substrate and the second substrate is electrically connected via the conductive part And a step of laminating a second substrate on the surface side of the substrate. The conductive portion may be formed by printing a conductive paste. In the adhesive lamination step, the adhesive may be laminated on both the first substrate surface and the second substrate back surface.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a multilayer printed wiring board.

  In recent years, in the electronic equipment field, with the increase in the density of electronic equipment, multilayered printed wiring boards used as parts of electronic equipment have progressed. Conventionally, various methods have been proposed for manufacturing these multilayer printed wiring boards. For example, a conductor circuit is formed on the surface of a circuit board via a resin layer, a hole for a via hole is formed in a current-carrying portion of the resin layer, and metal plating is applied to the hole for the via hole to electrically connect the circuit board and the conductor circuit. A method for manufacturing a build-up type multilayer printed wiring board is disclosed (Japanese Patent Laid-Open No. 8-279678).

  In addition, a method for manufacturing a multilayer printed wiring board in which the surfaces of a circuit board having conductor circuits are bonded with an anisotropic conductive adhesive and the boards are laminated is disclosed (Japanese Patent Laid-Open No. 2010-206233).

JP-A-8-279678 JP 2010-206233 A

  In the manufacturing method described in the above-mentioned JP-A-8-279678, when the resin layer and the conductor circuit are stacked and formed, it is necessary to perform metal plating for electrically connecting each conductor circuit, so that a multilayer There is a disadvantage that the manufacturing process of the printed wiring board becomes complicated and the manufacturing cost becomes high.

  In the manufacturing method described in JP 2010-206233 A, the anisotropic conductive adhesive needs to increase the content of conductive particles in order to improve the electrical connectivity between conductor circuits. In this case, the mechanical bond strength between the circuit boards is lowered. On the other hand, in order to improve the mechanical adhesive strength between circuit boards, it is necessary to reduce the content of conductive particles, but in this case, the electrical connectivity between conductor circuits decreases. That is, when the anisotropic conductive adhesive is used, the mechanical adhesive strength and the electrical connectivity are in a trade-off relationship.

  The present invention has been made in view of the above inconveniences, and can easily and reliably electrically connect the current-carrying portions of the opposing substrates, and can improve mechanical adhesion strength and electrical connectivity. It aims at providing the manufacturing method of the multilayer printed wiring board which can be compatible.

The invention made to solve the above problems is
Manufacturing a multilayer printed wiring board in which a first substrate having a current-carrying part exposed on the front surface and a second substrate having a current-carrying part exposed on the back side of the first substrate facing the current-carrying part A method,
Forming a conductive portion made of conductive paste on the surface of the current-carrying portion of the first substrate;
Laminating an adhesive around the current-carrying part in a plan view of the first substrate surface or the back surface of the second substrate;
And laminating the second substrate on the surface side of the first substrate so that the current-carrying portions facing each other of the first substrate and the second substrate are electrically connected via the conductive portion. .

  The manufacturing method of the multilayer printed wiring board includes a step of forming a conductive part made of a conductive paste on the surface of the current-carrying part of one substrate, and adhesion around the current-carrying part in a plan view of one substrate surface or the other substrate back surface. And the step of laminating the agent, the current-carrying portions of the opposing substrates can be easily and reliably electrically connected by the conductive portions, and at the same time, the substrates can be mechanically bonded by the adhesive. As a result, the manufacturing method of the multilayer printed wiring board can reduce the production cost of the multilayer printed wiring board and can obtain a highly reliable multilayer flexible printed wiring board.

  The conductive portion may be formed by printing a conductive paste. By forming the conductive portion by printing in this way, the conductive portion can be easily and reliably formed. As a result, the productivity of the method for manufacturing the multilayer printed wiring board can be further improved.

  In the adhesive lamination step, the adhesive may be laminated on both the first substrate surface and the second substrate back surface. Thus, by laminating the adhesive on the bonding surfaces of both the first substrate and the second substrate, the mechanical bond strength between the first substrate and the second substrate can be further increased.

  In the adhesive laminating step, the adhesive layer may be laminated on the surface side of the conductive part. Thus, by laminating the adhesive layer on the surface side of the conductive part, it is possible to prevent the conductive part from falling off the surface of the first substrate.

  The manufacturing method of the multilayer printed wiring board can easily and reliably obtain a multilayer printed wiring board capable of achieving both improvement in mechanical adhesive strength and improvement in electrical connectivity.

FIG. 1 is a schematic end view (a cut surface is a surface perpendicular to a substrate) showing a method for producing a multilayer printed wiring board according to an embodiment of the present invention. FIG. 2 is a schematic end view (a cut surface is a plane perpendicular to the substrate) showing a manufacturing method of a multilayer printed wiring board of an embodiment different from the manufacturing method of the multilayer printed wiring board of FIG. FIG. 3 is a schematic end view (cut surface is a plane perpendicular to the substrate) showing a method of manufacturing a multilayer printed wiring board according to an embodiment different from the method of manufacturing the multilayer printed wiring board of FIGS. 1 and 2.

  Hereinafter, embodiments of a method for producing a multilayer printed wiring board according to the present invention will be described in detail with reference to the drawings.

The manufacturing method of the multilayer printed wiring board shown in FIG. 1 includes a first substrate 1 on which a current-carrying part 1b is exposed on the front surface side, and a current-carrying part 11b on the back surface side of the first substrate 1 at a position facing the current-carrying part 1b. Is a method of manufacturing the multilayer printed wiring board 101 formed by laminating the second substrate 11 exposed. The manufacturing method of the said multilayer printed wiring board has the following processes.
(1) Step of forming conductive portion 2 made of conductive paste on the surface of current-carrying portion 1b of first substrate 1 (conductive portion forming step)
(2) A step of laminating the adhesive 3 around the energizing portion 1b in a plan view of the surface of the first substrate 1 (first substrate adhesive laminating step)
(3) Step of laminating the second substrate 11 on the surface side of the first substrate 1 (substrate) so that the respective energizing portions facing each other of the first substrate 1 and the second substrate 11 are electrically connected via the conductive portion 2 (Lamination process)
(4) The process of heating the said laminated body and adhere | attaching the 1st board | substrate 1 and the 2nd board | substrate 11 (heating process)

<(1) Conductive part forming step>
In the conductive part forming step, a conductive part 2 made of a conductive paste is formed on the surface of the energizing part 1b of the first substrate 1 as shown in FIG.

  The first substrate 1 includes an insulating layer 1a and a conductive pattern formed on the back surface of the insulating layer 1a. In this conductive pattern, a current-carrying portion 1b is formed for energizing the second substrate 11 facing the first substrate 1. The insulating layer 1a on the surface side of the energization portion 1b is formed with an opening 1c for exposing the energization portion 1b to the surface side.

  The insulating layer 1a is composed of a sheet-like member having flexibility and electrical insulation. Specifically, a resin film can be adopted as the insulating layer 1a. As the main component of this resin film, for example, polyimide, polyethylene terephthalate, or the like can be used, and polyimide is preferably used from the viewpoint of flexibility and strength.

  Although it does not specifically limit as a minimum of the average thickness of the insulating layer 1a, 5 micrometers is preferable and 10 micrometers is more preferable. Moreover, although it does not specifically limit as an upper limit of the average thickness of the insulating layer 1a, 100 micrometers is preferable and 50 micrometers is more preferable. If the average thickness of the insulating layer 1a is less than the above lower limit, the strength of the insulating layer 1a may be insufficient, and if it exceeds the upper limit, it may be contrary to the demand for thinning.

  The energizing portion 1b is a part of the conductive pattern formed on the surface of the insulating layer 1a. This conductive pattern is formed in a desired planar shape (pattern) by etching the metal layer laminated on the insulating layer 1a. The conductive pattern including the energization portion 1b can be formed of a conductive material, but is generally formed of, for example, copper.

  The method for laminating the metal layer for forming the conductive pattern on the insulating layer 1a is not particularly limited. For example, a bonding method in which a metal foil is bonded with an adhesive, or a resin composition that is a material for the insulating layer 1a on the metal foil. Casting method for coating, sputtering / plating method for forming a metal layer by electrolytic plating on a thin conductive layer (seed layer) with a thickness of several nanometers formed on the insulating layer 1a by sputtering or vapor deposition method, heat the metal foil A laminating method or the like attached by a press can be used.

  Although it does not specifically limit as a minimum of the average thickness of the electrically conductive pattern containing the electricity supply part 1b, 2 micrometers is preferable and 5 micrometers is more preferable. Moreover, although it does not specifically limit as an upper limit of the average thickness of an electroconductive pattern, 30 micrometers is preferable and 20 micrometers is more preferable. If the average thickness of the conductive pattern is less than the above lower limit, the conductivity may be insufficient, and if the average thickness exceeds the upper limit, the request for thinning may be violated.

  Although it does not specifically limit as a diameter of the opening 1c, For example, they are 40 micrometers or more and 200 micrometers. The planar shape of the opening 1c is not particularly limited as long as the conductive portion 2 described later can be formed, and may be, for example, a circle or a rectangle.

  In addition, the 1st board | substrate 1 and the 2nd board | substrate 11 mentioned later may further have layers and sheets, such as a coverlay other than an insulating layer and a conductive pattern.

  The conductive part 2 is a conductive member made of a conductive paste for conducting the current-carrying part 1b of the first substrate 1 and the current-carrying part 11b of the second substrate 11, and is in a direction perpendicular to the surface of the first substrate 1 ( It has electrical conductivity in the thickness direction).

  The plan view shape and the cross-sectional shape of the conductive portion 2 are not particularly limited and can be appropriately designed according to the shape of the opening 1c. However, it is preferable that the opening 1c is filled from the viewpoint of improving conductivity. . As shown in FIG. 1, the conductive portion 2 may be laminated on the surface of the insulating layer 1a in the peripheral region of the opening 1c. By laminating the conductive portion 2 in this way, the conductive portion 2 can be reliably filled into the opening 1c. In addition, when the conductive part 2 is not filled in the opening 1c, the area of the conductive part 2 with respect to the bottom area of the opening 1c (the exposed area of the conductive part 1b) on the bottom surface (the surface of the conductive part 1b) of the filling hole 1c. The ratio is preferably 80% or more, more preferably 90% or more. When the area ratio is less than the lower limit, there is a risk that sufficient electrical connectivity between the first substrate 1 and the second substrate 11 cannot be obtained.

  As the maximum height of the conductive portion 2, when the energizing portion 11b of the second substrate 11 is fitted into the opening 1c, the average thickness of the insulating layer 1a of the first substrate 1 (the average depth of the opening 1c). It is preferable to set a value equal to or larger than a value obtained by subtracting a minimum thickness of a current-carrying portion 11b of the second substrate 11 to be described later. When the energization part 11b of the second substrate 11 is not fitted into the opening 1c, the maximum height of the conductive part 2 is the average thickness of the insulating layer 1a of the first substrate 1 (the average depth of the opening 1c). It is preferable to set it as above. When the maximum height of the conductive part 2 is less than the above lower limit, there is a possibility that sufficient electrical connectivity between the first substrate 1 and the second substrate 11 cannot be obtained. On the other hand, the upper limit of the maximum protruding length of the conductive part 2 from the surface of the insulating layer 1a of the first substrate 1 is preferably 50 μm, and more preferably 40 μm. When the maximum protruding length of the conductive portion 2 from the surface of the insulating layer 1a of the first substrate 1 exceeds the above upper limit, the thickness of the obtained multilayer printed wiring board may be unnecessarily large.

  As the conductive paste for forming the conductive part 2, a paste in which conductive particles such as metal particles are dispersed in a binder can be used.

  Examples of the metal particles include silver, platinum, gold, copper, nickel, palladium, and solder. Among these, silver powder and silver-coated copper powder exhibiting excellent conductivity are preferable.

  As a minimum of the content rate of the electroconductive particle of the electroconductive paste which forms the electroconductive part 2, 40 volume% is preferable, 45 volume% is more preferable, and 50 volume% is further more preferable. When the content rate of electroconductive particle is less than the said minimum, there exists a possibility that the electrical connectivity of the flexible printed wiring board 2 and the reinforcement board 3 may fall. On the other hand, as an upper limit of the content rate of the electroconductive particle of the electroconductive paste which forms the electroconductive part 2, 75 volume% is preferable and 70 volume% is more preferable. When the content rate of the electroconductive particle of an electroconductive paste exceeds the said upper limit, the fluidity | liquidity of an electroconductive paste falls and there exists a possibility that formation of the electroconductive part 2 may become difficult.

  Examples of the binder include an epoxy resin, a phenol resin, a polyester resin, a polyurethane resin, an acrylic resin, a melamine resin, a polyimide resin, a polyamideimide resin, and the like, and one or more of these are used. Can do. Among these, a thermosetting resin that can improve the heat resistance of the conductive paste is preferable, and an epoxy resin is particularly preferable.

  Examples of the epoxy resin used in the conductive paste include bisphenol A type, F type, S type, AD type, copolymer type of bisphenol A type and bisphenol F type, naphthalene type, novolac type, biphenyl type, dicyclopentadiene type. And phenoxy resin which is a polymer epoxy resin.

  The binder can be used by dissolving in a solvent. Examples of the solvent include ester-based, ether-based, ketone-based, ether-ester-based, alcohol-based, hydrocarbon-based, and amine-based organic solvents, and one or more of these are used. be able to. In addition, when forming the electroconductive part 2 by printing of an electrically conductive paste, it is preferable to use the high boiling point solvent excellent in printability, and specifically, it is preferable to use carbitol acetate, butyl carbitol acetate, etc.

  Furthermore, a curing agent can be added to the binder. Examples of the curing agent include amine curing agents, polyaminoamide curing agents, acid and acid anhydride curing agents, basic active hydrogen compounds, tertiary aminos, and imidazoles.

  In addition to the components described above, auxiliary agents such as thickeners and leveling agents can be added to the conductive paste. Moreover, an electrically conductive paste can be obtained by mixing said each component, for example with a three roll, a rotary stirring deaerator, etc.

  Although the formation method of the electroconductive part 2 is not specifically limited, Although the method of printing a conductive paste or the method of coating can be used, the printing which can form the electroconductive part 2 in the opening 1c easily and reliably is used. Is preferred. The printing method is not particularly limited, and for example, screen printing, gravure printing, offset printing, flexographic printing, inkjet printing, dispenser printing, and the like can be used.

<(2) First substrate adhesive lamination step>
In the first substrate adhesive laminating step, as shown in FIG. 1 (b), the first substrate 1 surface is bonded to the periphery of the energizing portion 1b (the first substrate 1 surface excluding the exposed portion of the energizing portion 1b) in a plan view. Agent 3 is laminated. Here, the adhesive 3 is laminated on the surface of the energizing portion 1b and the insulating layer 1a where the conductive portion 2 is not formed, and covers the side surface of the conductive portion 2. Specifically, the adhesive 3 is laminated on the surface of the insulating layer 1a and in the opening 1c (when the opening 1c is not filled with the conductive portion 2) so that the surface of the conductive portion 2 is exposed. Note that the conductive part 2 can be prevented from falling off by covering the side surface of the conductive part 2 with the adhesive 3.

  The adhesive 3 is not particularly limited as long as it has adhesiveness, and examples thereof include an epoxy resin, a polyimide resin, a polyester resin, a phenol resin, a polyurethane resin, an acrylic resin, a melamine resin, and a polyamideimide resin. A thermosetting resin is preferable from the viewpoint of heat resistance, an epoxy resin or a polyimide resin is particularly preferable from the viewpoint of adhesion to the substrate, and it is further preferable to use the same type of adhesive as the conductive paste forming the conductive part 2. preferable.

  The above-mentioned solvent, curing agent, auxiliary agent and the like can be appropriately added to the adhesive 3. In addition, conductive particles can be added to the adhesive 3 to improve conductivity. The upper limit of the amount of conductive particles added to the adhesive 3 is preferably 20% by volume, more preferably 10% by volume, and still more preferably 5% by volume. When the addition amount of the electroconductive particle of the adhesive agent 3 exceeds the said upper limit, there exists a possibility that the adhesiveness of the adhesive agent 3 may fall by the increase in the impurity in the adhesive agent 3. In addition, as an upper limit of ratio of content of the electroconductive particle of the adhesive agent 3 with respect to content of the electroconductive particle of the electroconductive part 2, 0.1 time is preferable and 0.05 time is more preferable.

  As a method for laminating the adhesive 3, a printing method or a coating method can be used. The printing method is not particularly limited, and for example, screen printing, gravure printing, offset printing, flexographic printing, inkjet printing, dispenser printing, and the like can be used. Moreover, it does not specifically limit as said coating method, For example, knife coating, die coating, roll coating, etc. can be used. In addition, when laminating the adhesive 3, it is preferable to perform a mask or the like so that the adhesive 3 is not laminated on the surface of the conductive portion 2.

  The average thickness (average coating thickness) of the adhesive 3 laminated on the surface of the first substrate 1 is the maximum protruding length of the conductive portion 2 from the surface of the insulating layer 1a of the first substrate 1 (the surface of the conductive portion 2). The maximum distance from the surface of the insulating layer 1a is preferably substantially the same. When the average thickness of the adhesive 3 is smaller than the maximum protruding length of the conductive part 2 from the surface of the insulating layer 1a of the first substrate 1, the resulting multilayer printed wiring board may not exhibit sufficient mechanical adhesive strength. . Conversely, when the average thickness of the adhesive 3 is larger than the maximum protruding length of the conductive portion 2 from the surface of the insulating layer 1 a of the first substrate 1, the conductive portion 2 does not contact the current-carrying portion 11 b of the second substrate 11. There is a fear. The average thickness of the adhesive 3 means an average distance from the surface of the insulating layer 1 a of the first substrate 1 to the surface of the adhesive 3.

<(3) Substrate lamination process>
In the substrate stacking step, as shown in FIG. 1 (d), the first substrate 1 and the second substrate 11 facing each other are electrically connected to each other through the conductive portion 2 as shown in FIG. The second substrate 11 is laminated on the substrate. Specifically, the first substrate 1 and the second substrate 11 are stacked by positioning so that the surface of the conductive portion 2 is in contact with the back surface of the energization portion 11 b of the second substrate 11.

  Similar to the first substrate 1, the second substrate 11 includes an insulating layer 11a and a conductive pattern formed on the back surface of the insulating layer 11a. In this conductive pattern, a current-carrying part 11b facing the current-carrying part 1b of the first substrate 1 is formed. The insulating layer 11a and the conductive pattern can be the same as those of the first substrate 1. The average thickness of the conductive pattern of the second substrate 11 is generally smaller than the average thickness of the insulating layer 1a of the first substrate 1 (average depth of the opening 1c). The method for producing a multilayer printed wiring board can be suitably used for bonding the one substrate 1 and the second substrate 11.

<(4) Heating process>
In the heating step, the laminated body of the first substrate 1 and the second substrate 11 obtained in the substrate lamination step is heated to bond them. The heating temperature is preferably 120 ° C. or higher and 200 ° C. or lower, and the heating time is preferably 30 seconds or longer and 120 minutes or shorter. By setting the heating temperature and the heating time in the above ranges, it is possible to effectively exhibit adhesiveness and suppress deterioration of the substrate and the like. It does not specifically limit as a heating method, For example, it can heat using heating means, such as oven and a hotplate. Moreover, in order to improve the adhesiveness of the 1st board | substrate 1 and the 2nd board | substrate 11, and to make the electroconductive part 2 contact | abut more reliably to these, the electroconductive part 2 and the adhesive agent 3 are made into the 1st board | substrate 1 and the time of a heating. It is preferable to narrow the pressure with the second substrate 11.

  By the manufacturing method, the multilayer printed wiring board 101 shown in FIG. In addition, by repeating the conductive part forming step, the first substrate adhesive laminating step, and the substrate laminating step, it is possible to laminate three or more substrates while conducting the current-carrying portions.

<Second substrate adhesive lamination process>
In addition, the manufacturing method of the said multilayer printed wiring board is the process (2nd board | substrate adhesive lamination | stacking) of laminating | stacking an adhesive agent around the electricity supply part 11b by planar view of the 2nd board | substrate 11 back surface between a board | substrate lamination process and a heating process. Step).

  As the adhesive to be laminated on the back surface of the second substrate 11, the same adhesive as that to be laminated on the surface of the first substrate 1 can be used, and it is preferable that they are the same from the viewpoint of adhesiveness. Also, the laminating method can be the same as the first substrate adhesive laminating step.

  When the adhesive is laminated on the back surface of the second substrate 11, the total value of the average thicknesses of the adhesive 3 laminated on the surface of the first substrate 1 and the adhesive laminated on the surface of the second substrate 11 is determined by the conductive part. It is preferable that the maximum protrusion length from the surface of the insulating layer 1a of the first substrate 1 is approximately equal to 2. When the total value of the average thickness of the adhesive is smaller than the maximum protruding length of the conductive portion 2 from the surface of the insulating layer 1a of the first substrate 1, the resulting multilayer printed wiring board may not exhibit sufficient mechanical adhesive strength There is. On the contrary, when the total value of the average thickness of the adhesive is larger than the maximum protruding length of the conductive part 2 from the surface of the insulating layer 1a of the first substrate 1, the conductive part 2 contacts the energizing part 11b of the second substrate 11. There is a risk of not touching. The total value of the average thickness of the adhesive is the average distance from the surface of the insulating layer 1a of the first substrate 1 to the surface of the adhesive 3 and from the back surface of the insulating layer 11a of the second substrate 11 to the back surface of the adhesive 3 It means the sum with the average distance.

<Advantages>
The manufacturing method of the multilayer printed wiring board includes the step of forming a conductive portion 2 made of conductive paste on the surface of the current-carrying part 1b of the first substrate 1, and the adhesive 3 around the current-carrying part in a plan view of the first substrate 1. The conductive portions 2 are electrically connected to the current-carrying portions of the first substrate 1 and the second substrate 11 that are opposed to each other, and at the same time, the adhesive 3 is used to connect these substrates to the machine. Can be bonded together. As a result, the manufacturing method of the multilayer printed wiring board can reduce the production cost of the multilayer printed wiring board and can obtain a highly reliable multilayer flexible printed wiring board.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  In the above embodiment, the adhesive 3 is laminated so that the surface of the conductive portion 2 is exposed. However, even if the adhesive 3 is laminated on the surface side of the conductive portion 2 in the adhesive lamination step as shown in FIG. Good. By laminating the adhesive 3 on the surface side of the conductive portion 2 in this way, it is possible to prevent the conductive portion 2 from dropping from the first substrate 1 until the substrate lamination step. In addition, when laminating | stacking the adhesive agent 3 on the surface of the electroconductive part 2 in this way, the electroconductive part 2 is flowed by the adhesive agent 3 laminated | stacked on the surface side of the electroconductive part 2 in a board | substrate lamination process and a heating process by pressure. The abutment surface abuts on the energization part 11 b of the second substrate 11.

  In the method for manufacturing the flexible printed wiring board shown in FIG. 2, the upper limit of the minimum distance from the surface of the conductive portion 2 to the surface of the adhesive 3 is preferably 15 μm, and more preferably 10 μm. When the minimum distance from the surface of the conductive part 2 to the surface of the adhesive 3 exceeds the upper limit, the conductive part 2 may not contact the current-carrying part 11 b of the second substrate 11. On the other hand, the lower limit of the minimum distance from the surface of the conductive part 2 to the surface of the adhesive 3 is preferably 1 μm. When the minimum distance from the surface of the conductive part 2 to the surface of the adhesive 3 is less than the above lower limit, the effect of preventing the dropout of the conductive part 2 may not be sufficiently obtained.

  The adhesive may be provided only on the second substrate. Furthermore, the adhesive only needs to be laminated around the current-carrying part in a plan view of at least the front surface of the first substrate or the back surface of the second substrate, and the side surface of the conductive part is not necessarily covered with the adhesive. In this way, when the adhesive is stacked apart from the conductive portion, the adhesive flows between the conductive portions by flowing the adhesive with pressure in the substrate stacking step and the heating step.

  Moreover, in each said embodiment, although the surface on the opposite side to the conductive pattern of a 1st board | substrate and the surface of the side which has the conductive pattern of a 2nd board | substrate were opposed, when laminating | stacking a single-sided board | substrate on a double-sided board | substrate As described above, the surfaces having the conductive patterns of the first substrate and the second substrate may be opposed to each other. In this case, no opening is formed in the first substrate, and the conductive portion is laminated on the exposed surface (surface opposite to the insulating layer) of the current-carrying portion of the first substrate.

  That is, as in the method for manufacturing the multilayer printed wiring board shown in FIG. 3, the insulating layer 21a and the energizing portion 21b laminated on the surface of the insulating layer 21a and energizing the opposing second substrate 11 (part of the conductive pattern) The manufacturing method for obtaining the multilayer printed wiring board 201 using the first substrate 21 on which is formed) is also within the scope of the present invention. The material, average thickness, and the like of the insulating layer 21a and the energizing portion 21b of the first substrate 21 can be the same as those of the first substrate 1 used in the multilayer printed wiring board manufacturing method of FIG. Further, the conductive part forming step shown in FIG. 3A, the first substrate adhesive laminating step shown in FIG. 3B, the substrate laminating step shown in FIG. It can be the same as the manufacturing method of a wiring board.

  In the above embodiment, the conductive portion may be formed on the back surface of the current-carrying portion of the second substrate instead of the surface of the current-carrying portion (in the opening) of the first substrate, but from the viewpoint of ease of formation of the conductive portion. It is preferable to form a conductive part in the opening of the first substrate.

  In the above embodiment, a multilayer printed wiring board using a plurality of substrates having a pair of corresponding energization portions has been described as an example, but also for a multilayer printed wiring board using a plurality of substrates each having a plurality of energization portions. The manufacturing method can be applied by forming conductive portions in the plurality of current-carrying portions, respectively.

  The method for producing a multilayer printed wiring board according to the present invention can easily and reliably obtain a multilayer printed wiring board used for components of electronic equipment.

DESCRIPTION OF SYMBOLS 1, 21 1st board | substrate 11 2nd board | substrate 1a, 11a, 21a Insulating layer 1b, 11b, 21b Current supply part 11c Opening hole 2 Conductive part 3 Adhesive 101, 201 Multilayer printed wiring board

Claims (4)

Manufacturing a multilayer printed wiring board in which a first substrate having a current-carrying part exposed on the front surface and a second substrate having a current-carrying part exposed on the back side of the first substrate facing the current-carrying part A method,
Forming a conductive portion made of conductive paste on the surface of the current-carrying portion of the first substrate;
Laminating an adhesive around the current-carrying part in a plan view of the first substrate surface or the back surface of the second substrate;
And laminating the second substrate on the surface side of the first substrate so that the current-carrying portions facing each other of the first substrate and the second substrate are electrically connected via the conductive portion. A method for producing a multilayer printed wiring board.   The manufacturing method of the multilayer printed wiring board of Claim 1 which forms the said electroconductive part by printing of an electrically conductive paste.   The manufacturing method of the multilayer printed wiring board of Claim 1 or Claim 2 which laminates | stacks the said adhesive agent on both the 1st board | substrate surface and the 2nd board | substrate back surface in the said adhesive bond lamination process.   The manufacturing method of the multilayer printed wiring board of Claim 1, Claim 2 or Claim 3 which laminates | stacks the said adhesive agent on the surface side of the said electroconductive part in the said adhesive bond lamination process.

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