JPH1126934A - Multilayered circuit board with through-hole conductive part and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered circuit board with a through-hole conductive part in which connection between an inside copper foil circuit pattern and a through-hole conductive part can be surely and simply made. SOLUTION: Copper foil circuit patterns 2a-2e are laminated through insulating layers 3a-3d so that a multilayered circuit substrate material can be prepared. A main through-hole 5a put through the central part of land parts 4a and 4e of outside copper foil circuit patterns 2a and 2e of the multilayered circuit substrate material and the central part of a land part 4c of an inner copper foil circuit pattern 2c is formed at the multilayered circuit substrate material. Auxiliary through-holes 5b... laminated with the main through hole 5a, and put through land parts 4a, 4c, and 4e are formed by the irradiation of laser beams. Conductive paste is packed in a through-hole 5 constituted of the main through-hole 5a and the auxiliary through holes 5b, and then the conductive paste is burnt so that a through-hole conductive part 6 can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer circuit board having a through-hole conductive portion and a method for manufacturing the same.

[0002]

2. Description of the Related Art A multi-layer circuit having a through-hole conductive portion for filling a through-hole penetrating a multi-layer circuit board with a conductive paste and electrically connecting a plurality of copper foil circuit patterns in the thickness direction of the multi-layer circuit board. Substrates are known. However, in the through-hole conductive portion using the conductive paste, the end surface of the land portion of the inner copper foil circuit pattern located in the inner layer of the multilayer circuit board does not sufficiently contact with the through-hole conductive portion, and between the two. There was a problem that resistance increased. This is because the inner wall surface of the through hole becomes rough when forming the through hole, and the metal particles such as silver particles of the conductive paste sufficiently contact the end surface of the inner copper foil circuit pattern exposed on the inner wall surface of the through hole. This is because they do not. In addition, the silver particles of the conductive paste have a scaly shape with an average diameter of 10 μm or more, and have a sufficient contact area with the end face of the circuit pattern having a thickness of about several tens of μm in the through hole. Because you can't. Therefore, there is a problem that the resistance value between the inner copper foil circuit pattern and the through-hole conductive portion becomes a relatively high resistance value of several hundred ohms or more.

Accordingly, the present applicant has disclosed in Japanese Patent Application Laid-Open No. H8-6496.
As shown in Japanese Patent Publication No. 6, a concave portion opening toward a part of a land portion and a through hole of the inner copper circuit pattern between the inner copper circuit pattern and the adjacent insulating layer is formed in the insulating layer, A technique for filling a part of the through-hole conductive portion into the recess is proposed. With this configuration, the through-hole conductive portion is connected to the portion exposed to the concave portion of the inner copper foil circuit pattern, so that the connection between the inner copper foil circuit pattern and the through-hole conductive portion is ensured.

[0004]

Various methods can be employed to form such a multilayer circuit board with through-hole conductive portions. For example, there is a method of forming a concave portion at a predetermined position of the insulating layer before laminating a plurality of copper foil circuit patterns via the insulating layer. Further, there is a method in which a heat-shrinkable resin is attached to an insulating layer, and the recess is formed by shrinking the heat-shrinkable resin by heat curing the insulating layer. Further, there is a method in which a porous resin material is attached to an insulating layer, and the porous resin material is foamed or expanded by heat for thermosetting the insulating layer to form a concave portion, and a porous portion made of a porous resin is formed in the concave portion. is there. However, each of these methods has a problem that the formation of the concave portion becomes complicated and the manufacturing cost of the multilayer circuit board increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer circuit board with a through-hole conductive part and a method of manufacturing the same, which can easily form a through-hole capable of securely connecting the inner copper foil circuit pattern and the through-hole conductive part. .

Another object of the present invention is to provide a multilayer circuit board with a through-hole conductive portion capable of accurately measuring an electronic component connected to an inner copper foil circuit pattern, and a method of manufacturing the same.

[0007]

According to the present invention, there is provided a multilayer circuit board comprising a plurality of copper foil circuit patterns laminated via an insulating layer, and at least one outer copper foil circuit pattern located on the outermost side. A through hole formed to penetrate the land portion and at least one land portion of the inner copper foil circuit pattern located in the inner layer; and a conductive paste filled in the through hole to electrically connect the land portions. A multi-layer circuit board with a through-hole conductive portion, comprising: In the present invention, the through hole is formed adjacent to the main through hole penetrating each land portion and the main through hole so as to communicate with the main through hole, and penetrates at least the land portion of the inner copper foil circuit pattern. And an auxiliary through hole penetrating through the multilayer circuit board. According to the present invention, by forming the auxiliary through-hole, an end face exposed to the auxiliary through-hole of the inner copper foil circuit pattern is formed. Thereby, the contact area between the inner copper foil circuit pattern and the through-hole conductive portion increases, and the connection between the two can be ensured.

[0008] When there are a copper foil circuit pattern that requires connection and a copper foil circuit pattern that does not require connection among a plurality of copper foil circuit patterns located in the inner layer, the position and shape of the auxiliary through hole are formed. By appropriately adjusting the dimensions and dimensions, there is an advantage that connection can be easily performed only to the inner copper foil circuit pattern requiring connection.

[0009] Such a multilayer circuit board with through-hole conductive portions is manufactured as follows. First, a multilayer circuit board material is formed by laminating a plurality of copper foil circuit patterns via an insulating layer (a multilayer circuit board material forming step). Next, a land portion of at least one outer copper foil circuit pattern located on the outermost side Forming a main through hole penetrating the land portion of at least one inner copper foil circuit pattern located in the inner layer (main through hole forming step); and adjoining the main through hole so as to communicate with the main through hole, A through hole is formed by forming an auxiliary through hole penetrating the multilayer circuit board so as to penetrate at least the land portion of the inner copper foil circuit pattern (auxiliary through hole forming step).
Next, a conductive paste is filled in the through-hole formed of the main through-hole and the auxiliary through-hole to form a through-hole conductive portion for electrically connecting the lands (through-hole conductive portion forming step).

The main through hole and the auxiliary through hole are formed by punching,
Since it can be easily formed with a drill, etc., if manufactured in this way, the connection between the inner copper foil circuit pattern and the through-hole conductive part can be reliably established only by forming the main through hole and the auxiliary through hole in the multilayer circuit board material. Through holes can be easily formed.

In place of the auxiliary through-hole penetrating the multilayer circuit board, an auxiliary hole extending inward from one outer surface of the multilayer circuit board and terminating at a position exposing the land portion of the inner copper foil circuit pattern may be provided. In that case, the through-hole conductive portion is connected to the exposed portion of the land portion of the inner copper foil circuit pattern. For this reason, the contact area between the inner copper foil circuit pattern and the through-hole conductive portion is greatly increased, and the connection between them is more reliable.

The conductive portion of the through hole may be formed so that the entirety of the auxiliary hole is filled with the conductive paste, or may be formed so that a part of the auxiliary hole is filled with the conductive paste. If the through-hole conductive portion is formed such that the conductive paste fills the entire auxiliary hole, the connection between the inner copper foil circuit pattern and the through-hole conductive portion is greatly improved. Further, as an example of forming the through-hole conductive portion so that a part of the auxiliary hole is filled with the conductive paste, a non-connection portion exposed to one outer surface side is formed in a land portion of the inner copper foil circuit pattern. Thus, a through-hole conductive portion can be formed so as to cover a part of the land portion. With this configuration, the non-connection portion can be used as a measurement electrode of an electronic component connected to the inner copper foil circuit pattern. When used as a measurement electrode in this way, the measurement of the electronic component can be performed without the intervention of the through-hole conductive portion having a high resistance value, so that the measurement of the electronic component can be performed accurately.

In order to manufacture a multilayer circuit board having a through-hole conductive portion having such a non-connection portion, the other side of the multilayer circuit board is formed so that the non-connection portion is formed on the land portion of the inner copper foil circuit pattern. The conductive paste may be filled into the through holes from the outer surface.

Further, both an auxiliary through-hole penetrating the multilayer circuit board and an auxiliary hole terminating at a position exposing a land portion of the inner copper foil circuit pattern may be provided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view of a multilayer circuit board with through-hole conductive portions according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line B1-B1 in FIG. is there. As shown in both figures, the multilayer circuit board 1 has a structure in which five circuit patterns 2a to 2e are laminated via four insulating layers 3a to 3d formed by curing a prepreg. The circuit patterns 2a to 2e are made of copper foil,
It has a thickness of several tens of μm. Circuit patterns 2a, 2e
Constitute the outer copper foil circuit pattern located on the outermost side of the multilayer circuit board 1, and the circuit patterns 2b to 2d constitute the inner copper foil circuit pattern located on the inner layer. As the prepreg used for the insulating layers 3a to 3d, an insulating sheet made of an imide-based resin, or a woven or nonwoven fabric of glass fiber or resin fiber mixed with paper impregnated with a thermosetting resin such as epoxy may be used. it can. Insulating layer 3a ~
3d has a thickness of 0.06 to 0.4 mm. Outer copper foil circuit patterns The circuit patterns 2a and 2e include lands 4a and 4e. Further, of the inner copper foil circuit patterns 2b to 2d, the inner copper foil circuit pattern 2c electrically connected to the outer copper foil circuit pattern circuit patterns 2a and 2e includes a land portion 4c. The multilayer circuit board 1 has a through hole 5 penetrating the multilayer circuit board 1.

The through hole 5 has one main through hole 5a.
And four auxiliary through holes 5b. The main through-hole 5a is formed by a hole having a circular cross-sectional shape penetrating through the lands 4a, 4c, 4e of the circuit patterns 2a, 2c, 2e.

The auxiliary through-holes 5b are formed in a slit shape having a rectangular cross section extending longitudinally in the radial direction of the main through-hole 5a, and are formed at equal intervals on the outer periphery of the main through-hole 5a. Have been. In addition, these auxiliary through holes 5b
Are formed so as to communicate with the main through-hole 5a, and penetrate the lands 4a, 4c, 4e. Insulating layer 3a ~
Curved surfaces 3e and 3f that are smoothly curved toward the center of the through hole 5 are formed above and below a portion between the auxiliary through holes 5b adjacent to each other in 3d. The curved surfaces 3e and 3f are used to form the insulating layer 3 when forming the main through hole 5a.
a to 3d are formed by compression. In the present embodiment, auxiliary through-holes 5b are formed corresponding to the portions where the curved surfaces 3e and 3f are formed.

A through-hole conductive portion 6 is formed in the main through-hole 5a and the auxiliary through-holes 5b of the through-hole 5. The through-hole conductive portion 6 is formed of a conductive paste, and electrically connects the lands 4a, 4c, and 4e. In this embodiment, in addition to the end face 4c1 exposed in the main through hole 5a of the land portion 4c of the inner copper foil circuit pattern 2c, the end face 4 exposed in the auxiliary through hole 5b.
Since the through-hole conductive portion 6 is also connected to c2..., the connection between the inner copper foil circuit pattern 2c and the through-hole conductive portion 6 is ensured.

The multilayer circuit board 1 of the present embodiment is manufactured as follows. First, the circuit patterns 2a to 2e are laminated via the insulating layers 3a to 3d to produce a multilayer circuit board material. Next, the outer copper foil circuit patterns 2a and 2e
A main through hole 5a is formed between the center of the land portions 4a and 4e of the inner copper foil circuit pattern 2c and the center of the land portion 4c of the inner copper foil circuit pattern 2c using a punching tool, a drill or the like. Next, through-holes 5b are formed by irradiating laser light to form auxiliary through-holes 5b communicating with the main through-holes 5a and penetrating the lands 4a, 4c and 4e. And
Air or an etchant is sprayed on the inner surface of the through hole 5 to remove hardened prepreg shavings and copper foil shavings from the inner surface of the through hole 5. Next, a conductive paste such as a resin silver paste is filled in the through holes 5 by using a suction force or a pin. Particularly, the filling is performed with care so as to be surely filled in the auxiliary through hole 5b. Next, the filled conductive paste was fired at a high temperature of about 150 to 200 ° C. to form a through-hole conductive portion 6 to complete the multilayer circuit board 1.

FIG. 2A is a plan view of a multilayer circuit board with a through-hole conductive portion according to another embodiment of the present invention, and FIG. 2B is a plan view of FIG. It is a sectional view taken on line B2.

In this figure, the same parts as those in FIG. 1 are denoted by the reference numerals obtained by adding 10 to the reference numerals used in FIG. 1, and the description thereof will be omitted. In the embodiment shown in this figure, the outer copper foil circuit pattern 1 is selected from the inner copper foil circuit patterns 12b to 12d.
The inner copper foil circuit patterns electrically connected to 2a and 12e are 12c and 12d. The through hole 15 has one main through hole 15a and two auxiliary holes 15b.
1 and 15b2. Main through hole 15a
Is formed by a hole having a circular cross section penetrating through each land portion 14a, 14c, 14d, 14e of the circuit patterns 12a, 12c, 12d, 12e. In this example, each land portion 14a, 14c, 14d, 14e is
As shown in FIG. 1, it is formed so as to be in contact with a part of an outer peripheral portion of the through hole, instead of an annular shape surrounding the entire through hole.

The auxiliary holes 15b1 and 15b2 are formed by holes having a circular cross section, and are formed on the outer periphery of the main through hole 15a so as to be arranged at equal intervals (to face each other on the circumference). I have. The auxiliary holes 15b1, 15b
b2 is connected to the main through hole 15a so as to communicate with the main through hole 15a.
a. The auxiliary hole 15b1 extends from one outer surface 11a of the multilayer circuit board 11 to the inside and terminates at a position where the land portion 14c of the inner copper foil circuit pattern 12c is exposed. The auxiliary hole 15b2 extends from one outer surface 11a of the multilayer circuit board 11 and terminates at a position exposing the land portion 14d of the inner copper foil circuit pattern 12d. As a result, the end surfaces 14c1 and 14d1 exposed on the main through hole 15a side and the exposed surfaces 14c2 and 14d exposed on one outer surface 11a side of the multilayer circuit board 11 are formed on the land portions 14c and 14d.
2 are formed.

In the main through hole 15a and the auxiliary holes 15b1 and 15b2 of the through hole 15, the through hole conductive portion 1
6 are formed. The through-hole conductive portion 16 is formed of a conductive paste, and each land portion 14a,
14c, 14d, and 14e are electrically connected. This through-hole conductive portion 16 is formed of the inner copper foil circuit pattern 1.
Land portions 14c and 14d are formed such that non-connecting portions 14c3 and 14d3 to which through-hole conductive portion 16 is not connected are formed on exposed surfaces 14c2 and 14d2 of 2c and 12d.
It is formed so as to cover a part of d. Non-connection part 14c
3 and 14d3 are formed in approximately half of the exposed surfaces 14c2 and 14d2 on the radial outside of the through hole 15. These unconnected portions 14c3 and 14d3 can be used as electrodes for measuring electronic components connected to the inner copper foil circuit patterns 12c and 12d, respectively.

In the present embodiment, the end surfaces 14 of the inner copper foil circuit patterns 12c and 12d exposed to the main through-hole 15a side are formed.
In addition to c1 and 14d1, exposed surfaces 14c2 and 14d
2 is also connected to the through-hole conductive portion 16, so that the connection between the inner copper foil circuit patterns 12c and 12d and the through-hole conductive portion 16 is ensured.

The multilayer circuit board 11 of this embodiment is manufactured as follows. First, the circuit patterns 12a to 12e are laminated via the insulating layers 13a to 13d to form a multilayer circuit board material. Next, the outer copper foil circuit pattern circuit pattern 1
A main through-hole 15a is formed between the lands 14a, 14e of the 2a, 12e and the lands 14c, 14d of the inner copper foil circuit patterns 12c, 12d using a punching tool, a drill or the like. Next, an auxiliary machine 15b1 which terminates at a position where the land 14c is exposed and an auxiliary hole 15b2 which terminates at a position where the land 14d is exposed are formed by an NC machine to communicate with the main through-hole 15a. 15 is completed. Then, similarly to the method of manufacturing the multilayer circuit board shown in FIG. 1, hardened prepreg shavings and copper shavings are removed from the inner surface of the through hole 15. Next, as shown by an arrow F, non-connection portions 14c3 and 14d3 to which the through-hole conductive portion 16 is not connected are formed from the other outer surface (the surface on which the outer copper foil circuit pattern 12e is formed) 11b of the multilayer circuit board 11. The conductive paste is filled into the through-hole 15 so as to perform the process. Next, the filled conductive paste was fired at a high temperature of 150 to 200 ° C. to form a through-hole conductive portion 16, thereby completing the multilayer circuit board 11.

In the embodiment shown in FIGS. 2A and 2B, the non-connection portions 14c3 and 14d3 are
A through-hole conductive portion 16 is formed in a part of the auxiliary holes 15b1 and 15b2. As shown in FIGS. 3A and 3B, the entirety of the auxiliary holes 15b1 and 15b2 is filled with a conductive paste. The hole conductive part 26 can also be formed. In this case, one outer surface 1 of the multilayer circuit board 11
When the conductive paste is filled into the through hole 15 by printing from the side 1a, the conductive paste can be efficiently filled in the entire auxiliary holes 15b1 and 15b2. Also, in this example, the outer surface of the through-hole conductive portion 26 is used as a measurement electrode of the electronic component connected to the inner copper foil circuit patterns 12c and 12d. Is difficult to measure accurately. However, the inner copper foil circuit pattern 12c,
Since the through-hole conductive portion 26 is connected to the entire exposed surfaces 14c2 and 14d2 of the 12d, the connection between the inner copper foil circuit patterns 12c and 12d and the through-hole conductive portion 26 is further ensured.

FIG. 4 is a plan view of a multilayer circuit board with through-hole conductive portions according to still another embodiment of the present invention. In this example, an auxiliary hole 35b1 that terminates at a position where the land portion 34c of the inner copper foil circuit pattern 32c is exposed.
And an auxiliary through hole 35b2 penetrating the multilayer circuit board 31. In the present embodiment, without terminating at the land portion 34d of the inner copper foil circuit pattern 32d,
An auxiliary through-hole 35b2 is formed by penetrating through the land 34d and the insulating layer 33d, and a conductive resin is filled in the auxiliary through-hole 35b2 to form a through-hole conductive part 36. It was manufactured in the same manner as in the example shown in B). In this example, the end face 34d1 exposed in the auxiliary through-hole 35b2 of the land 34d of the inner copper foil circuit pattern 32d.
Is connected to the through-hole conductive portion 36.

[0028]

According to the present invention, the contact area between the inner copper foil circuit pattern and the conductive portion of the through hole is increased, and the connection between them can be ensured. In addition, since the main through-hole and the auxiliary through-hole can be easily formed by punching, drilling, or the like, according to the manufacturing method of the present invention, only the main through-hole and the auxiliary through-hole are formed in the multilayer circuit board material, and the inner Through holes that can reliably connect the copper foil circuit pattern to the through hole conductive portion can be easily formed.

[Brief description of the drawings]

FIG. 1A is a plan view of a multilayer circuit board with a through-hole conductive portion according to an example of an embodiment of the present invention;
FIG. 2B is a sectional view taken along the line B1-B1 in FIG.

FIG. 2A is a plan view of a multilayer circuit board with through-hole conductive portions according to another example of the embodiment of the present invention;
FIG. 2B is a sectional view taken along line B2-B2 in FIG.

3A is a plan view showing a modification of the multilayer circuit board with through-hole conductive portions shown in FIG. 2, and FIG. 3B is a sectional view taken along line B3-B3 in FIG. 3A.

FIG. 4 is a plan view of a multilayer circuit board with through-hole conductive portions according to still another example of the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 multilayer circuit board 2a, 2e outer copper foil circuit pattern 2b-2d inner copper foil circuit pattern 3a-3d insulating layer 4a, 4c, 4e land 5 through hole 5a main through hole 5b auxiliary through hole 6 through hole conductive portion

Continuing on the front page (72) Ryu Ichiro, Inventor 3158, Shimo-Okubo, Osawano-cho, Kamishinkawa-gun, Toyama Prefecture Inside (72) Inventor Morikatsu Yamazaki 3158, Shimo-Okubo, Osano-cho, Kami-Shinkawa-gun, Toyama Hokuriku Electric Industry Co., Ltd. Inside

Claims (11)

[Claims] A multi-layer circuit board formed by laminating a plurality of copper foil circuit patterns via an insulating layer; a land portion of at least one outer copper foil circuit pattern positioned at an outermost position; and at least a land portion positioned at an inner layer. A through hole formed so as to penetrate a land portion of one inner copper foil circuit pattern; and a through hole conductor formed by filling a conductive paste in the through hole and electrically connecting the land portions. And a multilayer circuit board with a through-hole conductive portion, comprising: a main through-hole penetrating through each of the lands, and adjacent to the main through-hole so as to communicate with the main through-hole. And an auxiliary through-hole penetrating the multilayer circuit board so as to penetrate at least the land portion of the inner copper foil circuit pattern. -Multilayer circuit board with conductive holes. 2. A multilayer circuit board comprising a plurality of copper foil circuit patterns laminated via an insulating layer, at least one land part of at least one outer copper foil circuit pattern and at least one located at an inner layer. A through hole formed so as to penetrate a land portion of one inner copper foil circuit pattern; and a through hole conductor formed by filling a conductive paste in the through hole and electrically connecting the land portions. And a multilayer circuit board with a through-hole conductive portion, comprising: a main through-hole penetrating through each of the lands, and adjacent to the main through-hole so as to communicate with the main through-hole. An auxiliary hole extending inward from one outer surface of the multilayer circuit board and terminating at a position exposing the land portion of the inner copper foil circuit pattern. Characteristic multilayer circuit board with through-hole conductive part. 3. The multilayer circuit board with through-hole conductive portions according to claim 2, wherein the through-hole conductive portions are formed by filling the entirety of the auxiliary holes with the conductive paste. 4. The through-hole conductive portion is formed so as to cover a part of the land portion of the inner copper foil circuit pattern such that a non-connection portion to which the through-hole conductive portion is not connected is formed on the land portion of the inner copper foil circuit pattern. The multilayer circuit board with a through-hole conductive part according to claim 2, wherein the non-connection part is used as a measurement electrode of an electronic component connected to the inner copper foil circuit pattern. 5. A multi-layer circuit board formed by laminating a plurality of copper foil circuit patterns via an insulating layer; and a land portion of at least one outer copper foil circuit pattern located on the outermost side and 2 located on an inner layer. A through-hole formed so as to penetrate the land portion of the inner copper foil circuit pattern; and a through-hole conductive layer formed by filling the through-hole with a conductive paste and electrically connecting the land portions. And a multilayer circuit board with a through-hole conductive portion, comprising: a main through-hole penetrating through each of the lands, and adjacent to the main through-hole so as to communicate with the main through-hole. An auxiliary through-hole penetrating the multilayer circuit board so as to penetrate the land portion of one or more of the inner copper foil circuit patterns, and the main through-hole so as to communicate with the main through-hole. An auxiliary hole formed adjacent to the hole, extending inside from one outer surface of the multilayer circuit board, and terminating at a position exposing the land portion of another one of the inner copper foil circuit patterns. Characteristic multilayer circuit board with through-hole conductive part. 6. A multilayer circuit board material forming step of laminating a plurality of copper foil circuit patterns via an insulating layer to form a multilayer circuit board material, and a land portion of at least one outermost copper foil circuit pattern located on the outermost side And a main through-hole forming step of forming a main through-hole penetrating the land portion of at least one inner copper foil circuit pattern located in the inner layer; and adjoining the main through-hole so as to communicate with the main through-hole,
Forming an auxiliary through hole penetrating the multilayer circuit board so as to penetrate at least the land portion of the inner copper foil circuit pattern to form a through hole; an auxiliary through hole forming step; and the main through hole and the auxiliary through hole Forming a through-hole conductive portion forming a through-hole conductive portion for electrically connecting the lands by filling a conductive paste into the through-hole formed of Method. 7. A multilayer circuit board material forming step of laminating a plurality of copper foil circuit patterns via an insulating layer to form a multilayer circuit board material, and a land portion of at least one outermost copper foil circuit pattern located on the outermost side And a main through-hole forming step of forming a main through-hole penetrating the land portion of at least one inner copper foil circuit pattern located in the inner layer; and adjoining the main through-hole so as to communicate with the main through-hole,
An auxiliary hole forming step of forming an auxiliary hole extending inward from one outer surface of the multilayer circuit board and terminating at a position exposing the land portion of the inner copper circuit pattern to form a through hole; And a through-hole conductive portion forming step of forming a through-hole conductive portion for electrically connecting between the lands by filling a conductive paste in a through-hole formed of the auxiliary through-hole. A method for manufacturing a multilayer circuit board. 8. In the through hole conductive portion forming step,
8. The through-hole conductive portion is formed by filling the entirety of the auxiliary hole with the conductive paste.
3. The method for manufacturing a multilayer circuit board with through-hole conductive portions according to item 1. 9. In the through hole conductive portion forming step,
As a non-connection portion where the through-hole conductive portion is not connected to the land portion of the inner copper foil circuit pattern,
8. The method according to claim 7, wherein the through-hole conductive portion is formed so as to cover a part of the land portion. 10. The method according to claim 9, wherein a conductive paste is filled into the through hole from the other outer surface of the multilayer circuit board. 11. A multilayer circuit board material forming step of laminating a plurality of copper foil circuit patterns via an insulating layer to form a multilayer circuit board material, and a land portion of at least one outermost copper foil circuit pattern located on the outermost side And a main through-hole forming step of forming a main through-hole penetrating the land portion of at least one inner copper foil circuit pattern located in the inner layer; and adjoining the main through-hole so as to communicate with the main through-hole,
An auxiliary through-hole that penetrates the multilayer circuit board so as to penetrate the land portion of the one or more inner copper foil circuit patterns, and the multilayer that is adjacent to the main through-hole so as to communicate with the main through-hole. Forming an auxiliary hole extending inward from one outer surface of the circuit board and terminating at a position exposing the land portion of another inner copper circuit pattern, thereby forming a through hole; and forming an auxiliary through hole and an auxiliary hole. And a through-hole conductive portion for filling a conductive paste into a through-hole formed of the main through-hole, the auxiliary through-hole and the auxiliary hole to form a through-hole conductive portion for electrically connecting the lands. A method for manufacturing a multilayer circuit board with through-hole conductive parts, comprising: a part forming step.