JP2014067973A - Print wiring board with adhesive sheet, manufacturing method of the same, and manufacturing method of laminated print wiring board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a print wiring board with an adhesive sheet that is likely to have a fine wiring pattern or small via diameter with an easy alignment when forming a bottomed via in an adhesive sheet, and that can be used regardless of an aspect ratio of the print wiring board, and to provide a manufacturing method of the same and a manufacturing method of a laminated print wiring board using the same.SOLUTION: A print wiring board with an adhesive sheet includes a print wiring board having a flat connection terminal, a thermosetting adhesive sheet comprising a protective film and an adhesive material and temporarily adhered on the print wiring board, a bottomed via for interlayer connection penetrating through the adhesive sheet across the flat connection terminal, a conductive paste filled in the bottomed via and tentatively hardened, and a cavity opening penetrating through the adhesive sheet and the print wiring board for housing electronic component elements. There are also provided a manufacturing method of the same, and a manufacturing method of a laminated print wiring board using the same.

Description

  The present invention relates to a printed wiring board with an adhesive sheet, a manufacturing method thereof, and a manufacturing method of a bonded printed wiring board using the same.

  2. Description of the Related Art In recent years, as a mobile device product is becoming smaller and thinner, as represented by smartphones, printed wiring boards are also required to be smaller, thinner and more functional. Development of a component-embedded board is underway, but there are problems such as the commercial flow of printed wiring boards and built-in components, quality assurance, and so on. On the other hand, as an alternative technology, there are modules and packages using a printed wiring board having a cavity structure. For the production of printed wiring boards with a cavity structure, the base substrate and spacer substrate are advantageous because the so-called bonding method, in which a spacer substrate with a cavity opening is bonded onto the base substrate on which the components are mounted, is advantageous. There is a demand for a bonded printed wiring board and a method for manufacturing the same, to which a conductive connection can be added.

  Modules and packages with built-in components have also been put into practical use by a method in which a spacer substrate and a lid substrate are bonded together after components are mounted on a base substrate. Under the present circumstances, the printed wiring board with an adhesive sheet which affixed the adhesive sheet on the spacer board | substrate, and its manufacturing method are requested | required.

  As a method for manufacturing a bonded printed wiring board in which a conductive connection is added between the first printed wiring board and the second printed wiring board, the first printed wiring board having a connection terminal on the surface and the second printed wiring board are used. There is a method A in which an insulating adhesive sheet in which a conductive paste is filled in a through hole is sandwiched between a printed wiring board and connected by heating and pressing (Patent Document 1).

  In addition, the first printed wiring board having connection terminals on the surface and the second printed wiring board having through-holes are bonded by heating and pressing using an insulating adhesive sheet, and then the second printed wiring board. There is a method B in which the adhesive material that has penetrated into the through-holes is removed by laser and then conductively connected by precious metal plating or filling with conductive paste.

  Further, there is a method C in which the first substrate and the second substrate are bonded by heating and pressurizing with an insulating adhesive sheet, a prepreg, or the like, and then interlayer connection is performed by through holes penetrating both the substrates, thereby conducting conduction.

  After the first and second substrates are heated and pressed with an insulating adhesive sheet or prepreg, etc., bottomed vias that penetrate one of the substrates are formed by drilling or laser drilling from one side of both substrates. Then, there is a method D for conducting a conductive connection by precious metal plating or filling with a conductive paste.

JP 2003-188536 A

  With recent miniaturization of wiring patterns, via hole diameters and pitches for electrically connecting printed wiring boards have been miniaturized for printed wiring boards with adhesive sheets. In such a case, it is difficult to align the connection terminal of the printed wiring board and the through hole of the adhesive sheet. Furthermore, when manufacturing a bonded printed wiring board with a cavity structure, it is necessary to open the area to be the cavity part in the adhesive sheet and the printed wiring board in advance by router processing or the like. Since the change is likely to occur, a positional deviation from the opening of the printed wiring board also becomes a problem.

  In addition, as a method for manufacturing a bonded printed wiring board, via hole diameters and pitches for electrically connecting the first and second printed wiring boards have been miniaturized in recent years, and the above-described method A (Patent Document 1). ), It was difficult to align the connection terminals of the first and second printed wiring boards and the adhesive sheet through-holes. Furthermore, when manufacturing a bonded printed wiring board having a cavity structure, it is necessary to open an area to be a cavity portion in advance in the first or second printed wiring board to be an adhesive sheet and a spacer substrate by router processing or the like. However, since the adhesive sheet is apt to undergo dimensional changes by itself, positional deviation from the opening of the printed wiring board also becomes a problem.

  In the above-mentioned method B, the thickness of the second printed wiring board is thin, and in the bottomed via used for connecting the first and second printed wiring boards, the adhesive removal by laser and the subsequent noble metal plating / There is no problem if the conductive paste can be filled, but as the plate thickness increases and the via diameter decreases, the process capability in each process decreases, making it difficult to handle. In general, it is not suitable when the aspect ratio of the bottomed via connecting the first and second printed wiring boards is 0.8 or more.

  In the case of the above-described method C, it is common to use a mechanical drill for forming the through-hole, and it has been a problem that it cannot follow the miniaturization of the wiring pattern. In general, the minimum diameter of the mechanical drill is 0.1 mm.

  In the case of the method D, following the miniaturization is the same as in the case of the method C when using the mechanical drill, and when using the laser drill, it depends on the thickness of the printed wiring board to penetrate and the via diameter. As in Method B, it is difficult to apply when the aspect ratio is 0.8 or more.

  The present invention has been made in view of the above problems, and is advantageous for miniaturization of the wiring pattern and the via diameter by easy alignment when forming the bottomed via to the adhesive sheet, It is another object of the present invention to provide a printed wiring board with an adhesive sheet that can be applied regardless of the aspect ratio of the printed wiring board, a manufacturing method thereof, and a manufacturing method of a bonded printed wiring board using the printed wiring board.

The present invention is characterized by the following.
1. A printed wiring board having a flat connection terminal, a thermosetting adhesive sheet temporarily bonded on the printed wiring board with a protective film and an adhesive, and the flat connection terminal through the adhesive sheet Bottomed vias for interlayer connection, conductive paste filled in the bottomed vias and temporarily cured, and openings for cavities provided through the adhesive sheet and the printed wiring board for accommodating electronic component elements, A printed wiring board with an adhesive sheet.
2. A process for producing a printed wiring board with an adhesive sheet according to Item 1, wherein a thermosetting adhesive sheet comprising a protective film and an adhesive is temporarily bonded on a printed wiring board having flat connection terminals (A) And (B) forming a bottomed via for interlayer connection that penetrates the adhesive sheet after temporary bonding to reach the flat connection terminal, and a printed wiring board on which the adhesive sheet is temporarily bonded, A step (C) of forming an opening to be a cavity for housing an electronic component element, and a step of filling the bottomed via with a conductive paste and pre-curing (D)
And a method for producing a printed wiring board with an adhesive sheet.
3. A method for producing a bonded printed wiring board using the printed wiring board with an adhesive sheet according to Item 1, wherein the printed wiring board with an adhesive sheet is produced by the method for producing a printed wiring board with an adhesive sheet according to Item 2 (A to D), a step (E) of manufacturing a second printed wiring board having a flat connection terminal corresponding to a bottomed via filled with a conductive paste of the printed wiring board with the adhesive sheet, and with the adhesive sheet A step (F) of preparing a first printed wiring board with an adhesive by peeling off a protective film of the printed wiring board, and a bottomed base filled with a conductive paste of the first printed wiring board with the adhesive Manufacturing a bonded printed wiring board having a via and a heating and pressing step (G) for connecting the flat connecting terminal of the second printed wiring board corresponding to the bottomed via by heating and pressing. Law.

  According to the present invention, it is advantageous for the miniaturization of the wiring pattern and the miniaturization of the via due to the easy alignment when forming the bottomed via on the adhesive sheet, and regardless of the aspect ratio of the printed wiring board. It is possible to provide a printed wiring board with an adhesive sheet that can be applied, a manufacturing method thereof, and a manufacturing method of a bonded printed wiring board using the same.

It is sectional drawing of the printed wiring board with an adhesive sheet of this invention. It is sectional drawing which shows a part of manufacturing method of the printed wiring board with an adhesive sheet of this invention. It is sectional drawing which shows a part of manufacturing method of the bonding printed wiring board of this invention. It is sectional drawing of the bonded printed wiring board of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Printed wiring board with adhesive sheet>
In FIG. 1, the printed wiring board 14 with an adhesive sheet of this Embodiment is shown. In the present embodiment, a printed wiring board 7 having a flat connection terminal 12, a thermosetting adhesive sheet 16 provided with a protective film 2 and an adhesive 1 and temporarily bonded onto the printed wiring board 7, and the adhesive sheet A bottomed via 11 for interlayer connection that passes through 16 and reaches the flat connection terminal 12, a conductive paste 6 filled in the bottomed via 11 and temporarily cured, an adhesive sheet 16, and a printed wiring board 7 A printed wiring board 14 with an adhesive sheet having a cavity opening 5 for penetrating and accommodating an electronic component element.

  An adhesive sheet is composed of a protective film and an adhesive. The adhesive surface with the protective film peeled off is brought into close contact with the material to be adhered, followed by pressurization, and the resin component of the adhesive is melted and cured by heating. It has the function of adhering. Temporary bonding is possible by adjusting heating or pressurization, and machining or laser processing can be performed after temporary bonding. Final bonding characteristics are obtained by further heating and pressurization (main bonding) with respect to temporary bonding.

  When the connecting terminal whose surface is flattened is constituted by a via flattened by a filled via and its land, a filling agent is filled in a through hole in which noble metal plating is applied to the inner wall of the through hole, If the connection terminal is a part whose surface has been flattened by lid plating, or if the connection terminal is flattened by a circuit (land etc.) drawn from each via and through hole, the through hole or bottomed This refers to the case where the via is filled with a conductive filler such as a conductive paste and hardened and the surface is flattened as a connection terminal.

  Conductive paste can be filled into vias and through holes for electrical connection, and conductive particles are mixed in slurry resin and cured by heating or pressing. Can do. It is used for the purpose of obtaining electrical connection via a conductive paste.

  In the printed wiring board with an adhesive sheet of the present embodiment, since it is possible to perform laser processing on the flattened connection terminals in a state where the thermosetting adhesive sheet is adhered to the printed wiring board, it is conventional. It becomes easy to align the connection terminal of the printed wiring board and the adhesive sheet through-hole, which was a problem. Furthermore, when manufacturing a printed wiring board with an adhesive sheet or a bonded printed wiring board having a cavity structure, it is necessary to open the adhesive sheet and the printed wiring board separately in advance by a router process or the like, respectively, in the area that becomes the cavity portion. In addition, since the opening can be performed using a router processing machine or the like with the adhesive sheet temporarily bonded to the printed wiring board, the process is simplified and the positional accuracy of the opening is improved.

<Method for producing printed wiring board with adhesive sheet>
In FIG. 2, the manufacturing method of the printed wiring board 14 with an adhesive sheet of this Embodiment is shown. In the manufacturing method of the printed wiring board 14 with the adhesive sheet of the present embodiment, a thermosetting adhesive sheet 16 including the protective film 2 and the adhesive 1 is temporarily provided on the printed wiring board 7 having the flat connection terminals 12. A step (A) of bonding, a step (B) of forming a bottomed via 11 for interlayer connection passing through the adhesive sheet 16 after the temporary bonding and reaching the flat connection terminal 12, and the adhesive sheet 16 A step (C) of forming a cavity opening 5 for accommodating an electronic component element (not shown) on the printed wiring board 7 temporarily bonded with the conductive paste 6 is filled in the bottomed via 11 and temporarily cured. Step (E).

  According to the method for manufacturing a printed wiring board with an adhesive sheet of the present embodiment, it is possible to perform laser processing with the thermosetting adhesive sheet attached to the printed wiring board and facing the flattened connection terminals. Therefore, it is easy to align the connection terminal of the printed wiring board and the adhesive sheet through hole, which has been a problem in the past. Furthermore, when manufacturing a printed wiring board with an adhesive sheet or a bonded printed wiring board having a cavity structure, it is necessary to open the adhesive sheet and the printed wiring board separately in advance by a router process or the like, respectively, in the area that becomes the cavity portion. In addition, since the opening can be performed using a router processing machine or the like with the adhesive sheet temporarily bonded to the printed wiring board, the process is simplified and the positional accuracy of the opening is improved.

<Method for producing bonded printed wiring board>
2 and 3 show a manufacturing method of the bonded printed wiring board 15 of the present embodiment. The method for manufacturing the bonded printed wiring board 15 according to the present embodiment is a method for manufacturing the bonded printed wiring board 15 using the printed wiring board 14 with the adhesive sheet of FIG. 1 and includes the printed wiring board with the adhesive sheet of FIG. 14, the steps (A to D) of manufacturing the first printed wiring board 7 with the adhesive 1 and the conductive paste 6 of the first printed wiring board 7 with the adhesive 1 are filled. The step (E) of manufacturing the second printed wiring board 8 having the flat connection terminals 13 corresponding to the bottomed vias 11 and the step (F) of peeling off the protective film 2 of the printed wiring board 14 with the adhesive sheet A bottomed via 11 filled with the conductive paste 6 of the first printed wiring board 7 with the adhesive 1 and a flat connection terminal 13 of the second printed wiring board 8 corresponding to the bottomed via 11. And Having a heating and pressing step of connecting pressurizes (G), the.

  According to the method for manufacturing a bonded printed wiring board according to the present embodiment, it is possible to perform laser processing with the thermosetting adhesive sheet attached to the printed wiring board and facing the flattened connection terminals. Therefore, it is easy to align the connection terminal of the printed wiring board and the adhesive sheet through hole, which has been a problem in the past. Furthermore, when manufacturing a printed wiring board with an adhesive sheet or a bonded printed wiring board having a cavity structure, it is necessary to open the adhesive sheet and the printed wiring board separately in advance by a router process or the like, respectively, in the area that becomes the cavity portion. In addition, since the opening can be performed using a router processing machine or the like with the adhesive sheet temporarily bonded to the printed wiring board, the process is simplified and the positional accuracy of the opening is improved.

  Moreover, in the manufacturing method of the bonded printed wiring board of this Embodiment, it is used for the connection of a 1st printed wiring board and a 2nd printed wiring board, noble metal plating with respect to a connection via and a through hole, and an electrically conductive paste Therefore, there is an effect that the connection can be made regardless of the aspect ratio of the printed wiring board to be bonded.

  Hereinafter, although the Example of the printed wiring board with an adhesive sheet of this invention, its manufacturing method, and the manufacturing method of a bonded printed wiring board using the same is described, this invention is not limited to a present Example.

Example 1 Printed Wiring Board with Adhesive Sheet <Adhesive Sheet>
As the adhesive sheet 16, an insulating adhesive sheet AS-2600 having a thickness of 0.025 mm, a length of 500 mm, and a width of 400 mm (trade name, manufactured by Hitachi Chemical Co., Ltd.) was prepared (FIG. 2 (1)).

<Printed wiring board>
As a copper-clad laminate for the printed wiring board 7, MCL-E679 having a thickness of 0.20 mm, a length of 500 mm, and a width of 400 mm, in which a copper foil (18 μm) is laminated and integrated on both sides of an insulating layer made of glass epoxy. -FG (Hitachi Chemical Industry Co., Ltd., brand name) was prepared (FIG. 2 (2)).

Next, L1 (shows the conductor on the lower surface side of FIG. 2 (2). The same applies hereinafter) and L2 (shows the conductor on the upper surface side of FIG. 2 (2). The same applies hereinafter.) In addition, as an etching resist, dry film NIT225 (product name, manufactured by Nichigo Morton Co., Ltd.) is temporarily pressure-bonded with a laminator, a film-like photomask is bonded, and a conductive pattern is formed on both sides with an ultraviolet ray having an exposure amount of 140 mJ / cm ^2. The resist was baked and developed with a 0.9% by mass aqueous sodium carbonate solution to form an etching resist. Thereafter, the portion without the etching resist was removed by etching with a copper chloride etching solution. At this time, a conformal mask was formed on the L2 side, the opening was 100 μm in diameter, and the copper foil on the L2 side was left over.

  Next, laser processing was performed from the opening of the conformal mask on the L2 side to form a non-through via for interlayer connection. Further, through holes for interlayer connection were formed by drilling.

  Next, filled via plating was performed. Filled vias filled with plating were formed in non-through vias, and through-hole plating was formed in through holes.

  Next, the through hole in which the through hole plating was formed was filled with a hole filling resin, and then the upper surface (L2 side) of the through hole filled with the filled via and the hole filling resin was flattened by buffing.

  Next, after forming the base copper plating by electroless copper plating, the lid plating was formed on the through hole filled with the hole filling resin by thickening with the electrolytic copper plating.

Next, the conductors on both sides were patterned by the subtracting method to form conductor patterns L1 and L2, and a printed wiring board 7 was produced (FIG. 2 (2)). In pattern formation by the subtract method, as an etching resist, dry film NIT225 (manufactured by Nichigo Morton Co., Ltd., trade name) is temporarily pressure-bonded with a laminator, a film-like photomask is bonded, and an exposure amount of 140 mJ / cm ² is used. Conductive patterns were baked on both surfaces and developed with a 0.9% by mass aqueous sodium carbonate solution to form an etching resist. Thereafter, portions without the etching resist were etched away with a copper chloride etching solution. At this time, the diameters of the flat connection terminal 12 on the filled via on the conductor pattern L2 side and the flat connection terminal 12 on the through hole were 130 μm.

<Temporary adhesion of adhesive sheet>
Next, AS-2600 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was temporarily bonded to the L2 side of the printed wiring board 7 as the adhesive sheet 16 (FIG. 2 (3)). Temporary bonding uses a hot press machine.
It was performed under the conditions of 70 ° C., 5.0 MPa, 30 seconds.

<Formation of bottomed via A>
Next, a bottomed via 11 for connection was formed on the adhesive sheet on the L2 side of the printed wiring board 7 to which the adhesive sheet 16 was temporarily bonded (FIG. 2 (4)).

  Details of the method for forming the bottomed via 11 will be described below. First, the bottomed via 11 was formed on the L2 side adhesive sheet 16 by laser processing using a carbon dioxide laser directly (FIG. 2 (4)). At this time, the alignment of the laser processing was performed by directly reading an alignment mark (not shown) added to the printed wiring board 7 by pattern formation. Therefore, the positions of the bottomed via 11 and the receiving pad (connection terminal 12) are In any case, the bottomed via 11 did not come off from the receiving pad (connection terminal 12), and the positional accuracy was good.

<Cavity processing>
Next, the cavity opening from the L1 side of the printed wiring board 7 through the insulating layer (substrate 10), the adhesive 1 and the protective film 2 to the conductive pattern L2 (adhesive sheet 16 side) of the printed wiring board 7 5 was formed (FIG. 2 (5)). The cavity opening 5 was made by router processing.

<Conductive paste filling>
Next, the conductive paste 6 was filled in the bottomed via 11 added to the adhesive sheet 16 of the printed wiring board 7 to which the adhesive sheet 16 was temporarily bonded. (FIG. 2 (6)).

  As the conductive paste 6, DD paste AE1651 (product name, manufactured by Tatsuta System Electronics Co., Ltd.) is prepared and filled by a printing method using a screen printer through a metal mask corresponding to the via position formed in the formation of the bottomed via 11. did.

<Dry>
Next, the printed wiring board 14 with an adhesive sheet obtained by printing the conductive paste 6 on the adhesive sheet 16 was dried with a box-type dryer. Drying conditions are 80 ° C. and 60 minutes. The printed wiring board 14 with an adhesive sheet was produced by the above.

(Example 2) Bonded printed wiring board

<Printed wiring board with adhesive sheet>
In the same manner as in Example 1, a printed wiring board 14 with an adhesive sheet was produced according to FIGS.

<Second printed wiring board>
As a copper-clad laminate for the second printed wiring board, MCL with a thickness of 0.20 mm, a length of 500 mm, and a width of 400 mm is obtained by laminating and integrating copper foil (18 μm) on both sides of a glass epoxy insulating layer. -E679-FG (trade name, manufactured by Hitachi Chemical Co., Ltd.) was prepared (not shown).

Next, a dry film NIT225 (trade name, manufactured by Nichigo Morton Co., Ltd.) is temporarily bonded with a laminator as an etching resist to L1 (not shown) and L2 (not shown) of the copper-clad laminate, and the film A photomask is pasted and a conductive pattern is baked on both sides with an ultraviolet ray with an exposure amount of 140 mJ / cm ² and developed with a 0.9% by mass aqueous sodium carbonate solution to form an etching resist. Was removed by etching with a copper chloride etchant. At this time, a conformal mask was formed on the L2 side, the opening was 100 μm in diameter, and the copper foil on the L2 side was left over.

  Next, laser processing was performed from the opening of the conformal mask on the L2 side to form a non-through via for interlayer connection.

  Next, filled via plating was performed, and filled vias filled with plating were formed in the non-through vias.

  Next, the conductor on the L2 side was patterned by the subtract method to form a conductor pattern L2 (not shown).

Next, an insulating layer and a copper foil are laminated and formed on the conductor pattern L2 side, a conformal mask is formed on the copper foil, and laser processing is performed from the opening of the conformal mask to form a non-through via for interlayer connection, Repeat filled via plating and pattern formation several times,
A second printed wiring board 8 having four layers of conductors was produced. Here, on the L4 side of the second printed wiring board 8 (the conductor on the uppermost surface side in FIG. 3 is shown), a bottomed via 11 filled with the conductive paste 6 of the printed wiring board 14 with an adhesive sheet is provided. A corresponding flat connection terminal 13 is provided (FIG. 3 (7)).

<Adhesive sheet protective film peeling step>
Next, the protective film 2 (made of polyethylene terephthalate) of the adhesive sheet 16 of the printed wiring board 14 with the adhesive sheet was peeled off from the end so that the conductive paste 6 protruded from the surface of the adhesive sheet 16. At this time, if the protective film 2 is not slowly peeled off from the adhesive sheet 16, a phenomenon occurs in which the paste adheres to the protective film 2 side.

<Heating and pressing>
The adhesive 1 side of the first printed wiring board 7 and the L4 side of the second printed wiring board 8 were overlapped and adhered by heating and pressing. When the first printed wiring board 7 and the second printed wiring board 8 were overlapped, a pin was inserted into a guide hole opened at a predetermined position of each substrate to prevent displacement. The thermocompression bonding was performed using a hot press apparatus under the conditions of 160 ° C., 3.5 MPa, and 60 minutes. By this heating and pressing, the adhesive 1 that was temporarily bonded and the conductive paste 6 that was temporarily cured are fully cured, and the connection terminals 12 of the first printed wiring board 7 and the second printed wiring board 8 are cured. A strong connection could be formed with the connection terminal 13.

1. 1. Adhesive material 2. Protective film 3. A through hole (having a flat connection terminal on the through hole) 4. Filled vias 5. Cavity opening 6. Conductive paste 7. First printed wiring board or printed wiring board Second printed wiring board 9. Laser light10. Substrate 11. Bottomed vias12. (Flat) connection terminal 13. (Corresponding flat) connection terminal 14. Printed wiring board with adhesive sheet15. Bonded printed wiring board 16. Adhesive sheet

Claims (3)

  A printed wiring board having a flat connection terminal, a thermosetting adhesive sheet temporarily bonded on the printed wiring board with a protective film and an adhesive, and the flat connection terminal through the adhesive sheet Bottomed vias for interlayer connection, conductive paste filled in the bottomed vias and temporarily cured, and openings for cavities provided through the adhesive sheet and the printed wiring board for accommodating electronic component elements, A printed wiring board with an adhesive sheet. It is a manufacturing method of the printed wiring board with an adhesive sheet of Claim 1,
Step (A) of temporarily adhering a thermosetting adhesive sheet comprising a protective film and an adhesive on a printed wiring board having flat connection terminals;
A step (B) of forming a bottomed via for interlayer connection that penetrates the adhesive sheet after temporary bonding and reaches the flat connection terminal;
A step (C) of forming a cavity opening for accommodating an electronic component element on a printed wiring board on which the adhesive sheet is temporarily bonded; and a step (E) of filling the bottomed via with a conductive paste and temporarily curing the conductive paste. ,
The manufacturing method of the printed wiring board with an adhesive sheet which has this. A method for producing a bonded printed wiring board using the printed wiring board with an adhesive sheet according to claim 1,
The process (AD) which manufactures the printed wiring board with an adhesive sheet by the manufacturing method of the printed wiring board with an adhesive sheet of Claim 2,
A step (E) of producing a second printed wiring board having a flat connection terminal corresponding to a bottomed via filled with a conductive paste of the printed wiring board with the adhesive sheet;
A step (F) of preparing a first printed wiring board with an adhesive by peeling off a protective film of the printed wiring board with an adhesive sheet;
The bottomed via filled with the conductive paste of the first printed wiring board with the adhesive material and the flat connection terminal of the second printed wiring board corresponding to the bottomed via are connected by heating and pressing. Heating and pressurizing step (G),
A method for producing a bonded printed wiring board having:

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