JP2001007524A - Manufacture of wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a wiring board wherein a manufacturing process is simplified by preventing conductor paste from running when a space for forming an in-layer wiring is filled with the conductor paste, in a ceramic laminating board that contains the in-layer wiring for lowering resistor of wiring. SOLUTION: Through holes 3 and a piercing hole 4 are formed in green sheets 11-14, and the through hole 3 is filled with conductor paste 6. Then heat reversible resin sheets 7, which are formed out of acrylic, cellulose, etc., and heat-decomposed so as not to remain in a wiring board when the green sheets 11-14 are baked, are laminated on the other surfaces 12b and 13b sides of the green sheets 12 and 13 in which the piercing holes 4 are formed, and then the piercing holes 4 are filled with the conductor paste 6. Continuously, a pattern is printed on the surfaces of the green sheets 11-14 by screen printing, etc., with the use of the conductor paste 6, and lastly all green sheets 11-14 are stacked and baked to complete the wiring board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a wiring board having an in-layer wiring for reducing wiring resistance and used for a hybrid IC or the like.

[0002]

2. Description of the Related Art In general, as a wiring board (thick film circuit board) used for a hybrid IC or the like, a laminated board is used for a circuit board having a large circuit scale or requiring a small size. Among them, the alumina laminated substrate has an advantage that it can be manufactured at low cost. However, the alumina laminated substrate has a drawback that the electric resistance is high because the wiring in the inner layer is made of a material containing W (tungsten) or Mo (molybdenum) as a main component.

Therefore, a method has been devised in which a space for in-layer wiring is formed in an insulating layer as shown in JP-A-5-21635 and this space is filled with a conductive paste. A general method of manufacturing a wiring board having such an intra-layer wiring space is shown in FIGS. 6 and 7 as schematic sectional process drawings.
The details of this step will be described below with reference to FIGS. In FIG. 6, T / H indicates a through hole.

First, as shown in FIG. 6 (a), green sheets J11 to J14 of an appropriate size are prepared for the required number of layers (here, four layers), and the green sheets J11 to J14 are formed by punching using a die or the like. A hole J2 and a space J3 for an in-layer wiring are formed. Next, the through-hole J2 is filled with a conductive paste J4 by screen printing or the like (FIG. 6).
(B)). Thereafter, as shown in FIG.
The conductor paste J4 is printed in a predetermined pattern on the layers 11 and J14. At this time, the conductive paste J4 is not printed on the sheets J12 and J13 on which the in-layer wiring space J3 is formed. Next, as shown in FIG. 6D, the sheet from the lowermost sheet J14 to the sheet J13 in which the in-layer wiring space J3 is formed are stacked. Then, a conductive paste J4 is filled in the in-layer wiring space J3 of the laminated sheet J13 using screen printing or the like to form an in-layer wiring J5 (FIG. 6).
(E)).

From above, a conductor pattern is printed in the same manner as in the step shown in FIG. 6C (FIG. 7A). Subsequently, the sheet J12 on which the space J3 for the wiring in the layer is formed is laminated (FIG. 7B), the space J3 for the wiring in the layer is filled (FIG. 7C), and the conductor is printed (FIG. 7D). ) Is performed in the same manner as in the method described above. Here, the conductor paste J4 is W
Alternatively, a material containing Mo as a main component can be used.

In this example, since there were two layers of green sheets J12 and J13 on which the in-layer wiring J5 was formed, the steps of lamination, filling of the in-layer wiring space J3, and conductor printing were repeated twice. If there are n layers of green sheets on which is formed, it is necessary to repeat at most n times. After that, the remaining sheets J11 are laminated and fired at a temperature of about 1600 ° C. to complete the wiring board.

[0007]

Here, in the step of filling the conductive paste J4 into the in-layer wiring space J3,
As shown in FIG. 8, a sheet J7 made of paper or the like for preventing adhesion of the conductive paste J4 is placed on a stage J6, and a green sheet J1 and a pattern mask J8 are sequentially arranged thereon. Fig. 8 for J9
When the green sheet J1 is lifted from the printing stage J6 after filling, the conductive paste J4 is moved downward (in the direction of arrow B in FIG. 8). ).
Therefore, in order to form this structure, as shown in FIG. 6, another green sheet J14 as a saucer is laminated below the green sheet J13 in which the in-layer wiring space J3 is formed in advance. (FIG. 6 (d))
Thereafter, a method of filling the conductive paste J4 (FIG. 6E) was performed.

However, as described above, in the method of laminating the green sheet below the space J3 before filling the space J3 for the in-layer wiring, the lamination, filling and printing are performed on the green sheet having the space J3 for the in-layer wiring. Since it has to be repeated for the number of sheets, there is a problem that the manufacturing process is complicated and disadvantageous in cost.

Incidentally, in order to reduce the production cost, ideally, as shown in FIG. 9, the space J3 for the wiring in the layer is filled with the conductor paste J4 in advance, and the printed green sheets J11 to J11. It is preferable to stack J14 at once.

In order to actually perform such an ideally simplified manufacturing process, as shown in FIG. 8 described above, when the green sheet is lifted from the printing stage, the space for in-layer wiring is required. Therefore, it is difficult to appropriately manufacture a wiring board because of the problem that the conductive paste filled in the wiring board drips.

The present invention has been made in view of the above problems, and in a ceramic laminated substrate having an in-layer wiring for reducing the wiring resistance, the conductive paste dripping when filling the space for forming the in-layer wiring with the conductive paste. It is an object of the present invention to provide a method of manufacturing a wiring board in which the manufacturing process is simplified and the manufacturing process is simplified.

[0012]

According to the present invention, in order to attain the above object, the present invention comprises a multi-layer substrate on which a plurality of ceramic substrates (21 to 24) are laminated. The present invention is directed to a method of manufacturing a wiring board having a wiring pattern (5) formed by disposing a conductor member inside and on a surface thereof.

That is, in the manufacturing method according to the first aspect,
The other surface (12b, 13b) of the plurality of green sheets (12, 13) in which the through-holes (4) for forming in-layer wirings are formed is made of resin decomposed by heat so as to cover the openings of the through-holes. After the resin sheet (7) is attached, the through-hole is filled with the conductive paste (6), and then a plurality of green sheets (11 to 14) are laminated and fired.

According to the present invention, the conductive paste (6) filled in the through-hole (4) forms an in-layer wiring after firing, and the green sheet (1) having the through-hole is formed.
2, 13) Since the opening on the other surface (12b, 13b) side is covered with the resin sheet (7), the conductor paste can be filled from one surface (12a, 13a) side of the green sheet. It is possible to prevent the conductive paste from dripping when filling the through-hole with the conductive paste.

Further, the resin sheet (7) is thermally decomposed when the green sheets (11 to 14) are fired, and does not remain in the wiring board. Therefore, when filling the space for in-layer wiring as in the prior art, the lamination, filling, and printing are performed in the same manner as in the method of laminating the green sheet underneath in advance. It is not necessary to repeat the process for each minute, and a desired wiring board can be obtained by stacking the layers at the end, so that the manufacturing process can be simplified.

In the manufacturing method according to the second aspect, first, one surface (11a, 12a, 1) of the green sheets (11, 12, 14) is applied to the plurality of green sheets (11 to 14).
4a) to the other surface (11b, 12b, 14b) from the through hole (3) and the green sheet (12, 1).
3) From one side (12a, 13a) to the other side (12b, 13)
b) forming a through hole (4) having a larger opening area than the through hole (3), and filling the through hole with a conductive paste (6);
A step of attaching a resin sheet (7) made of a resin that decomposes by heat to cover at least the opening of the through hole on the other surface of the green sheet having the through hole, and attaching the resin sheet. A step of filling the through-hole with the conductive paste from one side of the green sheet is performed.

Next, in this manufacturing method, a pattern is formed on one surface (11a to 14a) of each of the green sheets (11 to 14) using the conductive paste (6), and finally, each of the green sheets (11 to 14) is formed. 14) is laminated and fired. The above is a feature of the present manufacturing method.

According to the present invention, similarly to the first aspect of the present invention, by using the resin sheet (7), the conductor when filling the conductive paste into the through-hole (4), which is a space for forming the intra-layer wiring, is provided. The resin sheet (7) can prevent the dripping of the paste, and the green sheet (11-1)
After baking in 4), the desired wiring board can be obtained by laminating it at the end without remaining in the wiring board, so that the manufacturing process can be simplified.

According to the third aspect of the present invention, the other surface (12) of the green sheet (12, 13) having the through hole (4) formed therein.
b, 13b) characterized in that a resin sheet (7) is attached to the entirety.

As a result, the green sheets (12, 1
By simply preparing the required number of resin sheets (7) having substantially the same shape as in (3), each resin sheet (7) can be easily attached to the green sheet.

The invention according to claims 4 to 6 is a modification of the manufacturing method according to claim 2. That is, in the invention according to claim 4, in the hole forming step,
After forming the through holes (3) and the through holes (4) in the green sheets (11 to 14), in the resin sheet attaching step, the green sheets (12, 1
3) Resin sheet (7) over the entire other surface (12b, 13b)
And a hole is made in a portion of the attached resin sheet that covers the opening of the through hole.

According to a fifth aspect of the present invention, after only the through holes (4) are formed in the green sheets (12, 13),
The other surface of the green sheet (12b,
13b), a resin sheet (7) is attached thereto, and subsequently, a through hole (3) is formed so as to penetrate to the attached resin sheet.

Further, in the invention according to claim 6, in the hole forming step, after forming the through holes (3) and the through holes (4) in the green sheets (11 to 14), A resin sheet (7) is attached to the green sheet (12) in which the through hole and the through hole are formed so as to cover only the through hole.

According to the inventions of the fourth to sixth aspects, in addition to the effect of the invention of the second aspect, the conductive paste is simultaneously or continuously formed in the through hole (3) and the through hole (4). Since (6) can be filled, the manufacturing process can be simplified. According to the fourth aspect of the invention, the same effect as the third aspect of the invention can be obtained.

The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0026]

(First Embodiment) FIGS. 1 and 2
2A to 2D are process diagrams showing a method for manufacturing a wiring board having a schematic cross-sectional configuration finally shown in FIG. 2B, and FIGS. 1A to 1D and FIG. FIG.

As shown in FIG. 2B, the wiring board of the present embodiment comprises a plurality of ceramic substrates 21, 22, 23, 24.
The conductor member 6a filled in the through hole 3 and the through hole 4 for forming an in-layer wiring inside the ceramic substrates 21 to 24 and the surface of each of the ceramic substrates 21 to 24 The wiring pattern 5 is constituted by the conductor member 6a formed in the above pattern.

Next, a method of manufacturing the wiring board will be described.
First, as shown in FIG.
14 are prepared for the required number of layers (four sheets in the illustrated example), and the green sheets 11 and
12, 14 from one side 11a, 12a, 14a to the other side 11
b, 12b, and 14b, and a through hole 4 that penetrates the green sheets 12, 13 from one surface 12a, 13a to the other surface 12b, 13b and has an opening area larger than the through hole 3. Hole forming step).

Here, alumina is used as the ceramic constituting the green sheets 11 to 14 in this embodiment.
Next, the conductive paste 6 is filled in the through holes 3 by a method such as screen printing, and the conductive paste 6 is dried (through hole filling step) (FIG. 1B).

Thereafter, as shown in FIG.
The other surfaces 12b, 1
The resin sheet 7 having substantially the same shape as the green sheets 12 and 13 is attached to 3b (resin sheet attaching step). Here, the resin sheet 7 is thermally decomposed at a temperature of about 1600 ° C. That is, it is possible to use a thermoplastic resin that is thermally decomposed when the green sheets 11 to 14 described below are fired and does not remain in the wiring board, and for example, acrylic or cellulose is preferable.

The thickness of the resin sheet 7 is set to 20 μm to 200 μm in view of its strength and thermal decomposability during firing.
It is preferable that As a bonding method, an organic solvent can be applied to the green sheets 12, 13 or the resin sheet 7 and then integrated.

Then, the green sheets 12, 13 with the resin sheet 7 adhered thereto are placed on a stage (not shown) of a printing machine with the surfaces 12a, 13a of the green sheets 12, 13 facing up, and screen printing is performed. The conductive paste 6 is printed and filled from the one surface 12a, 13a side of the green sheets 12, 13 (in-layer wiring forming step) (FIG. 1).
(D)). Next, as shown in FIG. 2 (a), the green sheets 12, 13 are peeled off from the stage, the conductive paste 6 is dried, and the green sheets 11 to 14 are patterned using the conductive paste 6 by screen printing or the like. Is printed, and the conductive paste 6 is dried (layer surface wiring forming step).

In this layer surface wiring forming step, it is preferable that the conductive paste 6 is printed so as to have a thickness of about 20 μm after drying. Subsequently, each green sheet 11
After laminating Nos. To 14, firing is performed at a temperature of about 1600 ° C. (lamination step). Here, the green sheets 12, 13
Is thermally decomposed during firing and does not remain inside the wiring board after firing. Thus, the wiring board of the present embodiment is completed (FIG. 2B).

Here, as the conductor paste 6 which becomes the conductor member 6a by being baked in the laminating step, a paste containing W or Mo as a main component can be used.

By the way, according to this embodiment, the through hole 4
Other surfaces 12b, 13 of the green sheets 12, 13 in
After the opening on the side b is covered with the resin sheet 7, the conductor paste 6 is printed from the one surface 12a, 13a side of the green sheets 12, 13, so that the resin sheet 7 functions as a so-called saucer. When the green sheets 12, 13 are separated from the stage after the conductive paste 6 is printed on the stage, the problem that the filled conductive paste 6 drips on the stage or the like can be solved.

In addition, since the resin sheet 7 is not decomposed and remains in the wiring board when it is fired in the laminating step, a step for removing the resin sheet 7 is not required. Therefore, when filling the through-hole with the conductive paste as in the prior art, it is necessary to repeat the lamination, filling and printing by using a method of previously laminating a green sheet under the through-hole to cover the opening of the through-hole. Instead, all the green sheets 11 to 14 can be stacked and fired at the end of the manufacturing process, so that the manufacturing process can be simplified.

Since the resin sheets 7 having substantially the same shape as the green sheets 12 and 13 are used, the required number of resin sheets 7 of one shape (two in the illustrated example) may be prepared. The resin sheet 7 can be easily attached to the green sheets 12 and 13 only by matching the outer edge of the resin sheet 7 with the outer edge of the resin sheet 7. (Second Embodiment) In a second embodiment, the manufacturing method of the first embodiment is modified, and two examples are given below.

FIG. 3 is a schematic sectional view showing a main part of a manufacturing process in a first example of the second embodiment. In the first example,
First, in the hole forming step shown in FIG.
Through holes 3 and through holes 4 in green sheets 11 to 14
To form Next, in the resin sheet sticking step of this example shown in FIGS. 3B and 3C, first, the other surfaces 12b, 13 of the green sheets 12, 13 in which the through holes 4 are formed.
b, the resin sheet 7 is adhered to the whole, and thereafter, a hole is made in the resin sheet 7 covering the opening of the through hole 3 by punching or the like.

As a result, of the green sheets 11 and 14 in which only the through holes 3 are formed and the green sheets 12 and 13 in which the through holes 4 are formed,
The openings of the through holes 4 on the other surfaces 12b, 13b of the 13 are covered with the resin sheet 7, and the through holes 3 are formed into the green sheets 12, 13 in an opened state. Then, FIG.
As shown in (d), the above-described through-hole filling step and the above-described in-layer wiring forming step are performed.

FIG. 4 is a schematic sectional view showing a main part of a manufacturing process in a second example of the second embodiment. In the second example,
First, in the hole forming step shown in FIG.
Only the through holes 4 are formed in the green sheets 12 and 13.
Next, as shown in FIG. 4B, the resin sheet 7 is attached to the entire other surfaces 12b and 13b of the green sheets 12 and 13 in which the through holes 4 are formed. Then, as shown in FIG. 4C, through holes 3 are formed in the green sheets 11 to 14 by punching or the like so as to penetrate to the bonded resin sheet 7. As described above, in this example, the resin sheet sticking step is performed as shown in FIG. 4B during the hole forming step shown in FIGS. 4A and 4C.

As a result, similarly to the first embodiment, the green sheets 11 and 14 in which only the through holes 3 are formed are provided.
And the other surfaces 12b, 13b of the green sheets 12, 13 in which the through holes 4 are formed.
The opening of the through hole 4 on the side is covered with the resin sheet 7, and the through holes 3 are formed with the green sheets 12 and 13 in an opened state. When the through holes 4 are formed in all the green sheets, a green sheet in which only the through holes 3 are formed is not formed.

Thereafter, as shown in FIG. 4D, the through hole filling step and the in-layer wiring forming step are performed.

Finally, in both the first and second examples, as in the first embodiment, as shown in FIG.
The layer surface wiring forming step and the laminating step are sequentially performed to complete the wiring board of the present embodiment. Here, in each step, the details of the method of forming the through holes 3 and the through holes 4 and the material of the resin sheet 7 are the same as in the first embodiment.

According to the present embodiment, the same effects as in the first embodiment can be exhibited. The through-holes 3 and the through-holes 4 can be filled by the same method such as screen printing. In this case, the filling of the conductive paste 6 into the through-holes 3 is performed by the green sheets 11, 12, 14 other surface 11b, 12b, 14
This is performed appropriately when the b side is open.

Therefore, in this embodiment, the other surface 12b
Green sheet 12 in which both through-hole 3 opening on the side and through-hole 4 covering the other surface 12b side are formed.
Therefore, the conductive paste 6 can be simultaneously filled into the through hole 3 and the through hole 4, and the manufacturing process can be simplified. After the conductive paste 6 is filled in the through holes 3, the conductive paste 6 is filled in the through holes 4.
May be continuously performed so as to fill them, and the order may be reversed. (Third Embodiment) A third embodiment is a modification of the manufacturing method of the first embodiment. FIG. 5 is a schematic sectional view of a manufacturing process according to the third embodiment. First, FIG.
In the hole forming step shown in FIG.
4, a through hole 3 and a through hole 4 are formed. Next, FIG.
In the resin sheet sticking step of the present embodiment shown in (b), the resin sheet 7 is attached to the green sheet 12 in which the through holes 3 and the through holes 4 are formed so as to cover only the through holes 4.

Therefore, when both the through hole 3 and the through hole 4 are formed in the green sheet 12, the resin sheet 7 having a shape that does not cover the through hole 3 is used. Also, the green sheet 13 has through holes 4
When only the green sheet 13 is formed, a resin sheet 7 having substantially the same shape as the green sheet 13 may be used.

Thereafter, as shown in FIG. 5C, the through hole filling step and the in-layer wiring forming step are performed, and finally, as in the first embodiment, as shown in FIG. The wiring forming step and the laminating step are sequentially performed to complete the wiring board of the present embodiment. Here, in each step,
The details of the method of forming the through holes 3 and the through holes 4 and the material of the resin sheet 7 are the same as in the first embodiment.

According to the present embodiment, the manufacturing process can be simplified as in the first embodiment. Also, the filling of the conductive paste 6 into the through hole 3 and the through hole 4 can be performed simultaneously or continuously as in the second embodiment, but in this embodiment, the green sheet 11 is further added. The process of forming the through-holes 3 and the through-holes 4 through 14 can be performed in one step by punching or the like, and the manufacturing process can be further simplified.

In any one of the first to third embodiments, when the green sheets 11 to 14 are laminated, the green sheet 1 having the through holes 4 formed therein is formed.
2, 13 may be in the uppermost layer or in the lowermost layer.

Further, in the plurality of green sheets, the green sheet forming the through holes 4 may be a single layer, or the through holes 4 may be formed in all the green sheets.

Further, the respective components of the conductive paste 6 filling the through holes 3, the conductive paste 6 filling the through holes 4, and the conductive paste 6 forming patterns on the surfaces of the green sheets 11 to 14 are W or Mo. May be the same or different as long as the main component is.

[Brief description of the drawings]

FIG. 1 is a process chart illustrating a method for manufacturing a wiring board according to a first embodiment.

FIG. 2 is a process chart showing a manufacturing method following FIG. 1;

FIG. 3 is a process chart showing a manufacturing method in a first example of the second embodiment.

FIG. 4 is a process chart showing a manufacturing method in a second example of the second embodiment.

FIG. 5 is a process chart showing a manufacturing method in a third embodiment.

FIG. 6 is a process chart showing a conventional method for manufacturing a wiring board.

FIG. 7 is a process drawing illustrating the method for manufacturing the wiring board following FIG. 6;

FIG. 8 is an explanatory diagram relating to a conventional filling of a conductive paste into a space for in-layer wiring.

FIG. 9 is a schematic cross-sectional view showing an ideal manufacturing process of a wiring board having an in-layer wiring.

[Explanation of symbols]

11, 12, 13, 14 ... green sheet, 21, 2
2, 23, 24: ceramic substrate, 3: through hole,
4 ... through hole, 5 ... wiring pattern, 6 ... conductor paste, 7
... Resin sheet.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takashi Nagasaka 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in Denso Corporation (reference) 5E346 AA12 AA15 AA43 BB01 CC17 CC60 DD02 DD13 DD34 EE25 EE29 FF18 GG03 GG05 GG06 GG08 GG09

Claims (6)

[Claims] 1. A plurality of green sheets (11-14) are arranged on one side (11a-14a) to the other side (11b-14).
b) providing a through hole (4) for forming an in-layer wiring penetrating therethrough;
After filling the through-hole (4) with the conductive paste (6),
In a method for manufacturing a wiring board formed by laminating and firing these green sheets (11 to 14), the other surface (12b, 12b) of the plurality of green sheets (12, 13) in which the through holes (4) are formed. 13b) a resin sheet (7) made of a resin that decomposes by heat is applied so as to cover the opening of the through hole (4), and then the conductive paste (6) is filled in the through hole (4). Subsequently, a method of manufacturing a wiring board, comprising laminating and firing the plurality of green sheets (11 to 14). 2. A multilayer substrate comprising a plurality of ceramic substrates (21 to 24) laminated thereon, and a wiring pattern (5) formed by using a conductive paste (6) inside and on the surface of the multilayer substrate. A method of manufacturing a wiring board comprising: forming a plurality of green sheets (11 to 14) on one surface (11a, 1) of the green sheets (11, 12, 14);
2a, 14a) to the other surface (11b, 12b, 14b), a through hole (3), and the green sheet (12, 13) from the one surface (12a, 13a) to the other surface (12b, 13b). A through hole (4) that penetrates and has an opening area larger than the through hole (3);
Forming a hole, forming a through hole, filling the through hole (3) with the conductive paste (6), and filling the through hole (4) with the green sheet (1).
A resin sheet attaching step of attaching a resin sheet (7) made of a resin that decomposes by heat to cover the other surface (12b, 13b) of (2, 13) so as to cover at least the opening of the through hole (4). From the one surface (12a, 13a) side of the green sheet (12, 13) to which the resin sheet (7) is attached, in the layer for filling the through-hole (4) with the conductive paste (6). After performing a wiring forming step, the through hole filling step and the in-layer wiring forming step, each of the green sheets (11 to 1) is formed.
4) performing a layer surface wiring forming step of forming a pattern on the one surface (11a to 14a) using the conductive paste (6); and performing the layer surface wiring forming step. 14) a laminating step of laminating and firing. 3. After performing the hole forming step, in the resin sheet attaching step, the entire other surface (12b, 13b) of the green sheet (12, 13) having the through hole (4) formed therein. The method for manufacturing a wiring board according to claim 2, wherein the resin sheet (7) is attached to the wiring board. 4. After the hole forming step, in the resin sheet attaching step, the entire other surface (12b, 13b) of the green sheet (12, 13) having the through hole (4) formed therein. The resin sheet (7) is adhered to the resin sheet (7).
3. The method according to claim 2, wherein a hole is formed in a portion covering an opening of the through hole, and thereafter, the through hole filling step and the in-layer wiring forming step are performed. Method of manufacturing a wiring board. 5. The method according to claim 5, wherein the hole forming step includes the step of forming the through hole.
Then, the resin sheet attaching step is performed, and subsequently, the through hole (3) is formed so as to penetrate to the attached resin sheet (7). 3. The method according to claim 2, wherein a hole filling step and the in-layer wiring forming step are performed. 6. The green sheet (12) in which the through hole (3) and the through hole (4) are formed in the resin sheet attaching step after performing the hole forming step. The wiring board according to claim 2, wherein the resin sheet (7) is attached so as to cover only the through hole (4), and thereafter, the through hole filling step and the in-layer wiring forming step are performed. Manufacturing method.