JP3279117B2 - Manufacturing method of flexible wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention does not use a process such as etching, with high production efficiency, and peeling in which the implementation of the method of manufacturing a flexible wiring board without causing disruption of the wiring pattern and an object due.

[0002]

2. Description of the Related Art Conventionally, as one method of producing a double-sided wiring board, there is a method of forming a circuit on one side and then forming a through hole to connect the circuits on both sides. In a copper foil etching substrate, for example, as shown in FIG.
0), and print the resist on the front and back surfaces respectively (11)
0, 120), after forming a wiring pattern on both sides by etching (130), printing a resist for copper plating only through holes for through holes (140) and copper plating (150) to form a double-sided wiring board. Formed and, if necessary, overcoat printing (160).

In addition, as shown in FIG. 9 (b), there is a method in which a silver paste is buried in a through hole for a through hole and dried (150a) instead of the copper plating (150).

[0004]

However, the manufacturing method as shown in FIG. 9A is not preferable in terms of safety and hygiene and production efficiency because it involves an etching and copper plating process and uses a powerful chemical. Also, the manufacturing method as shown in FIG. 9B is not preferable in terms of safety and hygiene and production efficiency for the same reason, since an etching step still exists.

Further, in FIG. 9 (b), a bonding portion between a silver paste and a copper foil pattern is formed around a through hole. In the silver paste, silver particles are dispersed in an organic resin. It is a soft material. On the other hand, the copper foil pattern is metallic copper, an inorganic material, and a hard material.

[0006] Therefore, the adhesiveness between them and the durability of the adhesive are not sufficient, and especially when the application is a flexible wiring board, if the bend is repeated during use, the dried silver paste and the copper foil become inconsistent. In some cases, peeling occurred between the two. As a manufacturing method other than those described above,
In the technique disclosed in JP-A-8-40895, FIG.
After the etching in (b), the copper paste is applied and dried from the front side and the back side from the land portion of the through-hole made of copper foil to the inside of the through-hole, and then the solder paste is applied and reflowed by soldering to connect the through-hole. It is carried out. Therefore, it is not changed that both sides of the substrate are in a conductive state through the bonding portion of the copper foil and the copper paste containing the resin, and when this is applied to the flexible wiring board, Again, the problem of peeling between the copper foil and the copper paste occurred.

[0007] The present invention does not use a process such as etching, with high production efficiency, and peeling in which the implementation of the method of manufacturing a flexible wiring board without causing disruption of the wiring pattern and an object due.

[0008]

[0009]

[0010]

[0011]

[0012]

According to a first aspect of the present invention, there is provided a method of manufacturing a flexible wiring board having a wiring pattern provided on both surfaces and a through hole for electrically connecting the wiring patterns, wherein the through hole for the through hole is formed. On one surface side of the provided first substrate, a second substrate having a wiring pattern formed of a conductive paste on the surface is adhered on the surface side, and then a nozzle is inserted into the through hole, Discharging the conductive paste from the nozzle and removing the second paste in the back of the through hole
The through hole is filled with a conductive paste so as to be in contact with the wiring pattern on the substrate surface, and then the conductive paste in the through hole is filled with the conductive paste on the other surface of the first substrate. This is a method for manufacturing a flexible wiring board for printing a wiring pattern to be connected.

According to a second aspect of the present invention, there is provided a method of manufacturing a flexible wiring board having wiring patterns provided on both sides and through holes for electrically connecting the wiring patterns, wherein the through holes for through holes are formed. A second substrate having, on one surface side of the first substrate provided, an air vent passage opening to the surface and a wiring pattern formed of a conductive paste on the surface;
The substrate is adhered on the surface side thereof, and then a lump of conductive paste is disposed in the opening on the other surface side of the through hole, and a wiring pattern is formed on the other surface side of the first substrate with the conductive paste. This is a method of manufacturing a flexible wiring board in which the conductive paste is pressed into the through-holes by printing and reaching the wiring pattern on the second substrate.

[0015]

[0016]

[0017]

[Effect of the action and Invention resulting et al by the manufacturing method of the present invention
In the flexible wiring board, the wiring pattern and the wiring in the through hole are formed by printing a conductive paste. Therefore, since the wiring pattern and the wiring in the through hole are both conductive pastes, if both conductive pastes are exactly the same conductive paste, the same material is bonded, so that the wiring pattern and the through hole are bonded. It is unlikely that the bonding portion with the wiring inside will be destroyed by peeling. Also, even if the conductive paste is not exactly the same, the conductive paste is required to have similar physical properties, and since the material is usually similar, the bonding between the wiring pattern and the wiring in the through hole is also required. The part is hardly destroyed by peeling.

Therefore, even when the present invention is applied to a flexible wiring board, it is possible to provide a highly durable flexible wiring board which is unlikely to cause adhesive peeling. Further, since the etching step can be omitted, printing can be performed with a printing machine without using a powerful chemical, and thus there is no problem in terms of safety and hygiene and production efficiency. Particularly, in order to perform etching, resist printing is repeated, and therefore, according to the present invention, all of the steps can be omitted, so that productivity is remarkably improved. In addition, since the wiring pattern can be formed almost only by printing, there is an effect of improving productivity over shortening the process.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

The wiring patterns provided on both surfaces and
Through hood that electrically connects
As a method of manufacturing a flexible wiring board having a through-hole, a second substrate having a wiring pattern formed of a conductive paste on a surface thereof is provided on one surface side of a first substrate provided with through holes for through holes. Side, and then insert a nozzle into the through-hole, discharge the conductive paste from the nozzle, and contact the wiring pattern on the surface of the second substrate at the back of the through-hole. filling the through hole with a conductive paste, it may then be a method of printing a wiring pattern connected to the conductive paste of the through hole in the first substrate of the other surface side in the conductive paste.

In this case, the two substrates are bonded to form one flexible wiring board. One nozzle is inserted into a through hole of the first substrate, one of which is closed by the second substrate.
Since the conductive paste can be reliably brought into contact with the wiring pattern on the surface of the second substrate at the back thereof, even if the conductive paste is a conductive paste with almost no flowability,
Wiring patterns made of conductive paste on both surfaces of the first substrate can be more reliably connected in the through holes.

As another method of manufacturing a flexible wiring board, an air vent passage opening on the surface and a wiring pattern formed of a conductive paste on the surface are provided on one side of the first substrate provided with through holes for through holes. The second substrate having the following structure is adhered on the front surface side, and then a lump of conductive paste is arranged in the opening on the other surface side of the through hole, and the conductive paste is placed on the other surface side of the first substrate. The printing may be performed by printing a wiring pattern and pressing the conductive paste mass into the through-hole by the printing to reach the wiring pattern on the second substrate.

Since air in the through hole of the first substrate, one of which is closed by the second substrate, can escape from the air vent passage of the second substrate, a mass of the conductive paste is arranged in the opening of the through hole. Thus, the mass of the conductive paste can be pushed into the through-hole at the time of printing. Therefore, the conductive paste can be reliably brought into contact with the wiring pattern on the surface of the second substrate at the back of the through-hole, so that even if the conductive paste is a conductive paste having almost no flowability, the conductive paste can be more reliably penetrated. Wiring patterns made of conductive paste on both surfaces of the first substrate can be connected in the holes.

[0033]

[0034]

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG . 1 is an explanatory view of a manufacturing process of a flexible wiring board. As shown in FIG. 1A, first, a substrate 2 is prepared. The substrate 2 may be made of any material as long as it is flexible and can be used as a substrate. Here, the thickness is around 100 μm to 250 μm.
The front and rear PET (polyethylene terephthalate) films are used. In addition, as a material of a flexible substrate,
In addition to PET, for example, PPS (polyphenylene sulfide), polyimide, a composite sheet of PET and PPS, glass epoxy substrate, BT resin material and the like are used. other
The same applies to the type of substrate material for the example .

Next, as shown in FIG. 1B, a through hole 4 for a through hole (for example, about 2 mm in diameter) is punched or drilled. As shown in FIG. 1 (3), the wiring pattern 6 is formed on the surface 2a side of the substrate 2 provided with the through-holes 4 for through-holes using a conductive paste having a flowing property.
Print. In addition, printing is also performed on the through hole 4 for a through hole. For this printing, for example, a printing method employed for printing a wiring pattern such as screen printing or metal mask printing is used.

As the conductive paste to be printed, a silver paste is used here. The silver paste is a paint in which silver particles are dispersed in a printing paint, and is dried (including solidification by a chemical reaction) by heating after printing to form a conductive printing pattern. Examples of such conductive paste include copper paste containing copper particles, copper / silver paste containing copper particles and silver particles, and silver / carbon paste containing silver particles and carbon particles, in addition to silver paste. And the like. In other examples , the same kind of conductive paste is used.

As shown in FIG. 1 (4), the flowability of the conductive paste is adjusted by the mixing ratio of the components of the conductive paste and the like. It flows down the inner wall surface 4a of the through hole 4. This flow stops at the latest during the drying process by heating immediately after this, and the leading end 8 of the conductive paste stops almost at a position past the vicinity of the center of the through hole 4 for a through hole.

Next, as shown in FIG. 1 (5), the substrate 2 is turned upside down, and the back surface 2b side is turned up. Print 10. As shown in FIG. 1 (6), the conductive paste is immediately applied to the inner wall surface 4a of the through hole 4 for a through hole.
, The tip 12 of the conductive paste comes into contact with the tip 8 of the conductive paste from the surface 2a side, and the conductive pastes slightly overlap each other. By performing the drying process in this state, the state in which the conductive paste on the front surface 2a side and the conductive paste on the back surface 2b side of the substrate 2 are electrically connected in the through hole 4 for through hole is fixed. You.

Through these steps, the through hole 14 is completed. Thus, the flexible wiring board 16 in which the wiring patterns 6, 10 and the wiring portions in the through holes 14 are printed with the conductive paste and dried is completed. In this example, only the wiring patterns 6 and 10 are printed on the front and back surfaces 2a and 2b of the substrate 2 with a conductive paste, respectively. Flows to form wiring, and the wiring patterns 6, 10 on the front and back surfaces 2a, 2b can be connected through the through holes 14, so that the manufacturing process is greatly reduced.

Further, since the wiring patterns 6 and 10 on both sides and the connection thereof need only be printed, the cost can be reduced more than simply shortening the manufacturing process. Also, since the wiring patterns 6, 10 and the wiring in the through hole 14 are both made of the same conductive paste and are made of the same material, the bonding portion between the wiring patterns 6, 10 and the wiring in the through hole 14 is bonded. Is not destroyed by peeling. Therefore, the completed flexible wiring board 16 is less likely to be peeled to cause disconnection, and becomes a highly durable flexible wiring board.

In this example, when the wiring pattern 6 is printed due to the properties such as the surface tension of the conductive paste in FIG. 1 (3) of the above-described example, as shown in FIG. In some cases, a film may be formed to cover the opening 4b of the through hole 4. In such a state, it becomes difficult for the conductive paste to flow down the inner wall surface 4a of the through hole 4 for a through hole.

In this example, the method is carried out when a conductive paste for forming such a film is used. After the step (3) in FIG. 1, as shown in FIG. Then, the substrate 2 is placed on the suction table 20, and the through holes 4 for through holes are formed.
And the suction hole 22 of the suction table 20 are aligned and placed. Since the lower portion of the suction table 20 has a negative pressure, air is discharged from the through hole 4 through the suction hole 22. This allows the opening 4b to be opened due to external atmospheric pressure.
The conductive paste 6a covering the through hole is broken, and the conductive paste is introduced into the through hole 4 for through-holes and adheres to the inner wall surface 4a. Therefore, the state is the same as that in FIG.

Next, as shown in FIG.
0, the conductive paste 10a covers the opening 4b of the through hole 4 and forms a film, as shown in FIG. 2 (2).
a hardly flows down the inner wall surface 4a of the through hole 4 for through holes.

Therefore, after the step of FIG.
As shown in (2), with the wiring pattern 6 facing down, the substrate 2 is placed on the suction table 20 with the through holes 4 for through holes and the suction holes 22 aligned. As a result, air is discharged from the inside of the through-hole 4 for the through-hole through the suction hole 22, and the conductive paste 10 a covering the opening 4 b is broken by the external atmospheric pressure, and the through-hole 4 for the through-hole 4 is broken.
And adheres to the inner wall surface 4a and comes into contact with the tip 8 of the conductive paste flowing down from the wiring pattern 6 on the surface 2a side. Therefore, the state is the same as that of FIG. Subsequent steps are the same as in the above-described example .

As described above, since the conductive paste is forcibly introduced into the through hole 4 for the through hole by the suction,
Even if a conductive paste that forms a film or has little flow-down property can connect the wiring patterns 6 and 10 on the front and back surfaces 2a and 2b in the through hole 4 for through holes more reliably. Other effects are the same as those in the above-described example .

[0047] Incidentally, such a suction process, Gotoku <br/> the example described above, good opening 4b of the through-hole through holes 4, with even showing a falling property without covering the conductive paste In this case, there is an effect of further promoting the flow of the conductive paste into the through holes 4 for through holes.

Firstly, up to the step shown in FIG. 3 (4) above
This is the same as the example . Then, after the wiring pattern 6 is dried, in a step shown in FIG. 3 (5), a conductive material is provided on the back surface 2b of the substrate 2 by a nozzle such as a dispenser so as to cover the opening 4b of the through hole 4 for a through hole. The paste is discharged, and the conductive paste mass 26 is arranged.

Next, in the step of FIG. 3 (6), the wiring pattern 1 is placed on the back surface 2b of the conductive paste mass 26 before drying.
Print 0. By this printing, the conductive paste mass 2
6 is pushed into the through hole 4 for a through hole. Thereby, the conductive paste reaches the tip 8 of the conductive paste flowing down from the surface 2a side. This is dried.

As described above, since the conductive paste mass 26 is forcibly pushed into the through-hole 4 for the through hole by the pressing force at the time of printing, the conductive paste printed particularly on the back surface 2b side has almost no flowability. Even if there is no conductive paste, the front and back surfaces 2 in the through-holes 4 for through-holes can be more reliably determined.
The wiring patterns 6 and 10 of a and 2b can be connected. Therefore, through holes can be easily formed even when a substrate having a thickness of, for example, about 800 μm is used.

The conductive paste mass 26 is disposed on the surface 2a side, and the conductive paste mass 26 is printed on the reverse side of the conductive paste mass 26 so that the conductive paste mass 26 is removed from the through hole 4d. And then dried, and then a conductive paste is printed on the back surface 2b side so that the through holes 4 for through holes are formed.
The inner wall surface 4a may flow down to reach the tip of the conductive paste mass 26 from the surface 2a side.

In this example, since the disposition of the conductive paste mass 26 is merely performed using a dispenser or the like, the process is sufficiently shortened as compared with the related art. Other effects are the same as those in the above-described example . This embodiment, as shown in FIG. 4, the through-hole 4 through holes in the above example
Is provided with a tapered portion 4c. That is, following the step of forming a hole in the substrate 2 shown in FIG. 4B, as shown in FIG. 4C, both of the front and back surfaces 2a and 2b of the through hole 4 for the through hole of the substrate 2 are formed. 4b is provided with a tapered portion 4c.

Therefore, when the wiring pattern 6 is printed on the surface 2a with the conductive paste, the conductive paste flows down along the tapered portion 4c. After this is dried, in the step shown in FIG.
Discharge is performed by a dispenser or the like so as to cover the tapered portion 4c of the through-hole 4 for through-hole or to inject the tapered portion 4c, and the conductive paste mass 26 is arranged.

Next, in the step of FIG. 4 (6), the wiring pattern 1 is placed on the back surface 2b of the conductive paste mass 26 before drying.
Print 0. By this printing, the conductive paste mass 2
6 is pushed into the through hole 4 from the tapered portion 4c. Thereby, the conductive paste reaches the tip 8 of the conductive paste flowing down from the surface 2a side. This is dried.

This embodiment has the same effect as the above-described embodiment, and the tapered portion 4c functions as a funnel, so that the conductive paste mass 26 is formed by the pressure during printing. It is easy to enter the inside of the through hole 4 for a through hole. Therefore, the wiring patterns 6 and 10 on the front and back surfaces 2a and 2b can be more reliably connected in the through holes 4 for through holes.

Also, in the printing of the wiring pattern 6 on the surface 2a as in the above-described example without using the conductive paste lump 26, if the tapered portion 4c is provided, the conductive paste can be used during or after printing. Since the tapered portion 4c is guided to the center of the tapered portion 4c by the slope, the front and back surfaces 2a,
2b wiring patterns 6 and 10 can be connected.

Of course, contrary to the order of the above-described steps, the conductive paste mass 26 is disposed on the front surface 2a side, and printing is performed on the conductive paste mass 26 so that the conductive paste mass 26 is formed through the through hole 4 for the through hole. After drying, a conductive paste is printed on the back surface 2b side to flow down the inner wall surface 4a of the through-hole 4 for through-holes. It may be a step of reaching.

The opening 4 of the through hole 4 for a through hole is provided.
b forms the tapered portion 4c, so that the angle of the opening 4b becomes obtuse, and even if the manufactured flexible wiring board is bent, the dried conductive paste at the corner of the opening 4b becomes A large destructive force is unlikely to act, and breakage or cracking is less likely to occur in the dried conductive paste at the corner of the opening 4b.

FIG . 5 shows the steps of the first embodiment according to the present invention.
You. The process up to (3) is the same as the above-described example (FIG. 4). However, the difference is that the through hole 4 for the through hole is provided with the tapered portion 4c only on the surface 2a side.

Next, as shown in FIG. 5D, an adhesive is applied to the back surface 2b side of the substrate 2 to form an adhesive layer 30. Next, as shown in FIG. 5 (5), the second substrate 40 is adhered to the back surface 2b side of the substrate 2 with the adhesive layer 30 to be integrated. As shown in FIG. 6A, the wiring pattern 42 is already formed on the second substrate 40 using a conductive paste. An air vent passage 44 is formed at a position corresponding to the through hole 4 for the through hole of the substrate 2, penetrating the second substrate 40 and the wiring pattern 42. This second
As shown in FIG. 6 (2), the surface 40a side of the substrate 40 is
The substrate 2 is adhered to the adhesive layer 30 existing on the back surface 2b side to be integrated.

Next, as shown in FIG.
The mass 52 of the conductive paste is discharged and arranged by a discharge nozzle or the like on the tapered portion 4c of the through hole 4 for the through hole on the side. Next, as shown in FIG.
The wiring pattern 54 is printed on the side with a conductive paste.
By this printing, the mass 52 of the conductive paste is pushed into the through-hole 4 for through-hole, and the conductive paste in the surface 2a side and in the through-hole 4 for through-hole is dried.

The air in the through-hole for a through hole 4, one of which is closed by the second substrate 40, can escape from the air vent passage 44 of the second substrate 40 to the back surface 40 b side of the second substrate 40. The conductive paste mass 52 can be pushed into the through-hole through hole 4 at the time of printing by arranging the conductive paste mass 52 in the tapered portion 4c in the opening 4b of the hole through hole 4. Accordingly, the conductive paste can be reliably brought into contact with the wiring pattern 42 on the surface of the second substrate 40 at the back of the through-hole 4 for through-holes, from the substrate 2 side. Even if the conductive paste is used, the wiring pattern 54 and the wiring pattern 42 can be more reliably connected by the conductive paste in the through hole 4 for a through hole. Other effects are the same as in the above-described example .

Instead of the first embodiment shown in FIGS. 5 (6) and (7), a process as shown in FIG. 7 may be executed. Air vent passage 44 to the second embodiment In the second substrate 40 does not exist. For this reason, as shown in FIG. 7A, a nozzle 60 is inserted into the through hole 4 for through hole, and the conductive paste 62 is discharged from the nozzle 60 to discharge the through hole 4 for through hole.
Wiring pattern 4 on the surface 40a of the second substrate 40 at the back of
The through-holes 4 for through holes are filled with the conductive paste 62 so that the conductive paste 62 comes into contact with 2. The state where the filling is completed is as shown in FIG.

Next, when the wiring pattern 54 is printed on the surface 2a side of the substrate 2 with a conductive paste having a flowing property, the conductive paste flows down the tapered portion 4c, as shown in FIG. Connect to conductive paste 62. Therefore, when this is dried, the wiring pattern 54 on the front surface 2a side of the substrate 2 and the wiring pattern 42 on the second substrate 40 adhered to the rear surface 2b side are connected.

In this case, one of the through holes 4 for through holes is closed by the second substrate 40 by bonding the two substrates 2 and 40 to form one flexible wiring board. By inserting the nozzle 60, the conductive paste 62 can be reliably brought into contact with the wiring pattern 42 on the surface 40 a of the second substrate 40 behind the nozzle 60, and the conductive paste 62 can be surely applied to both surfaces of the substrate 2 in the through hole 4 for a through hole. The existing wiring patterns 54 and 42 can be connected to each other with a conductive paste.

The opening 4b of the through hole 4 for a through hole
Is provided with the tapered portion 4c, the amount of the conductive paste flowing down becomes large even when the conductive paste flows down when the wiring pattern 54 is printed. The conductive paste 62 injected by the nozzle 60 inside the through hole 4 for use. Other effects are the same as those in the above-described example .

Conductive paste 6 injected by nozzle 60
2 is substantially equal to the volume of the through hole 4 for a through hole, as shown in FIG.
Can be in contact with the conductive paste 62 even if there is almost no flow of the conductive paste at the time of printing.

If the volume of the conductive paste 62 injected by the nozzle 60 is too large than the volume of the through hole 4 for a through hole, as shown by the broken line in FIG. As in the case of the first embodiment, the wiring pattern 54 is ejected by the pressing force at the time of printing,
An air vent passage 44 may be provided.

In the above-described example , the through-holes 4 for through-holes are also sucked into the conductive paste masses 26 and 52.
It may be introduced inside. Further, in each of the above embodiments, when sucking the conductive paste, both sides may be sucked as necessary, or only one side may be sucked.

The flexible wiring board manufactured in each of the above embodiments is useful for a remote IC card or the like. The remote IC card is also called an RF card or an RF tag, and can exchange information at a position away from an antenna or a reader / writer using radio waves or electromagnetic induction. This remote IC card is used not only for pallet management, entry / exit management, vehicle management, etc. but also for railway commuter passes, ski lift tickets, air baggage tags and the like.

The remote IC card for such an application has high durability without breaking the connection by the wiring pattern and the through hole even if it is slightly bent.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a flexible wiring board as an example .

FIG. 2 is an explanatory view of a manufacturing process of a flexible wiring board as an example .

FIG. 3 is an explanatory view of a manufacturing process of a flexible wiring board as an example .

FIG. 4 is a diagram illustrating a manufacturing process of a flexible wiring board as an example .

FIG. 5 is an explanatory diagram of a manufacturing process of the flexible wiring board of Example 1 .

FIG. 6 is an explanatory diagram of a substrate configuration according to the first embodiment.

FIG. 7 is an explanatory diagram of a manufacturing process of the flexible wiring board according to the second embodiment.

FIG. 8 is an explanatory diagram of a configuration of a through hole formed in Example 2 .

FIG. 9 is an explanatory view of a manufacturing process of a conventional flexible wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Substrate 2a ... Substrate surface 2b ... Substrate back surface 4 ... Through-hole for through-hole 4a ... Inner wall surface 4b ... Opening 4c ... Tapered part 6,10 ... Wiring pattern 6a, 10a, 62 ... Conductive paste 8,12 ... Tip of conductive paste 14... Through hole 16... Flexible wiring board 20... Suction table 22. Suction hole 26, 52... Conductive paste mass 30... Adhesive layer 40. ... Back surface of the second substrate 42, 54 ... Wiring pattern 44 ... Air vent passage 60 ... Nozzle

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 3/40 H05K 1/11

Claims (2)

(57) [Claims] 1. A method of manufacturing a flexible wiring board having a wiring pattern provided on both sides and a through hole for electrically connecting the wiring patterns, wherein the first substrate having a through hole for a through hole is provided. On one surface side, a second substrate having a wiring pattern formed of a conductive paste on the surface is adhered on the surface side, and then a nozzle is inserted into the through hole, and the conductive paste is supplied from the nozzle. The through-hole is filled with a conductive paste so as to discharge and contact the wiring pattern on the surface of the second substrate at the back of the through-hole. A method of manufacturing a flexible wiring board, wherein a wiring pattern connected to the conductive paste in the through hole is printed with the paste. 2. A method of manufacturing a flexible wiring board having wiring patterns provided on both surfaces and through holes for electrically connecting the wiring patterns, wherein the first substrate having a through hole for a through hole is provided. On one surface side, a second substrate having an air vent passage opening on the surface and a wiring pattern formed of a conductive paste on the surface is adhered on the surface side, and then an opening on the other surface side of the through hole is formed. By disposing a lump of conductive paste in the part, printing a wiring pattern with a conductive paste on the other surface side of the first substrate, and by pressing the lump of conductive paste into the through hole by this printing, Second
A method of manufacturing a flexible wiring board to reach a wiring pattern on a substrate.