JP3057766B2 - Thick film multilayer circuit board and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thick-film multilayer circuit board used for multi-layering a circuit board having through holes formed therein, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a circuit board made of an insulating material such as alumina, various circuit patterns are formed on the front and back surfaces, and a plurality of electronic components are mounted. In such a circuit board, a conductor connection through a through hole is performed as a technique for electrically connecting a circuit pattern between the front and back surfaces.

Further, a multilayer circuit board in which circuit boards on which independent circuit patterns are formed is laminated has been put to practical use.
In such a multilayer circuit board, a high-density mounting of electronic components becomes possible as well as a reduction in the size of a complicated circuit, and great expectations are placed on the realization of a complicated functional circuit.

[0004]

When circuit boards having through holes formed thereon are laminated, the through holes formed in the circuit boards cause irregularities in the laminated insulating layers and conductor patterns, and the multilayered circuit board has a multilayer structure. Hinder the transformation. Further, if air remains in the through hole confined by the insulating layer, the expansion and contraction of the air may cause separation from the conductor pattern, which may cause a decrease in the reliability of the circuit board.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a thick-film multilayer circuit board which prevents the occurrence of unevenness in the multilayering of a circuit board having a through-hole formed therein and prevents air from remaining in the through-hole, and a method of manufacturing the same. With the goal.

[0006]

According to the present invention, there is provided a thick-film multilayer circuit board which is formed of an insulating material and has a flat surface.
A circuit board (2) for forming a circuit, and the front and back of the circuit board
Single or multiple through holes (4a, 4a, 4
b) and a predetermined layer formed on the front and back surfaces of the circuit board by printing.
A thick conductor, and
Conduction between the circuits by conductors placed on the inner wall of the
Causing the first conductor pattern (6a, 6b, 6c, 6d )
And the first conductor pattern filled in the through hole.
And an insulator (resist 8) in a through hole that forms a uniform layer surface with the pattern and printed on the surface of the circuit board.
A first insulating layer (resist 10a, 10b) for forming a uniform layer surface with the first conductor pattern, and the first insulating layer;
The first conductor pattern and the insulator in the through hole
A second insulating layer (resist 12a, 12b) printed on the substrate to form a flat layer surface, and a table of the second insulating layer.
Second conductor patterns printed on the surface (14a, 14b,
14c, 14d) and covering the second conductor pattern
And formed on the second insulating layer.
Third insulating layer (resist 16a, 16b, 18a, 18
b) . In addition, the thickness of the present invention
In the film multilayer circuit board, the third insulating layer is
From the second conductor pattern to the surface of the second insulating layer
And the same layer surface as that of the second conductor pattern.
An insulating layer (resist 16a, 1
6b) and a table of the insulating layer and the second conductor pattern.
An insulating layer (resist 18a,
18b).

Further, according to the present invention, there is provided a method of manufacturing a thick film multilayer circuit board , comprising:
Forming a circuit board (2) for forming a circuit,
Single or multiple through holes
Forming a tool (4a, 4b);
It is said that a conductor is formed to a predetermined layer thickness by printing on the front and back sides
In addition, the conductor provided on the inner wall surface of the through hole
The first conductor pattern (6
a, 6b, 6c, 6d);
Insulation of through holes to form a uniform layer surface with conductor patterns
Step of filling an edge (resist 8) into the through hole
And the first conductor printed on the surface of the circuit board
A first insulating layer (resist) forming a uniform layer surface with the pattern
And installing the first insulation
Layer, the first conductive pattern and the through hole
Second insulation printed over the edge to form a flat layer surface
Providing a layer (resist 12a, 12b);
Second conductor pattern printed on the surface of the second insulating layer
Step of installing (14a, 14b, 14c, 14d)
Formed over the second conductor pattern
Next, a third insulating layer (layer) formed on the second insulating layer
Work to install the diest 16a, 16b, 18a, 18b)
And characterized in that: Also, the thick film of the present invention
The method for manufacturing a multilayer circuit board includes forming the third insulating layer.
The step of performing the second insulation from the second conductor pattern.
A second conductor pattern formed on the surface of the layer by printing;
An insulating layer that forms the same layer surface as the
Placing the insulating layer and the second conductor pattern
Of installing an insulating layer formed by printing on the surface of
And characterized by the following.

[0008]

[Action] Further, in thick-film multi-layer circuit substrate of the present invention, flat
Form a predetermined layer thickness on the front side of a circuit board that has
Single or multiple through conductors
A conductor is disposed on the inner wall surface of the through hole of the first conductor path.
A turn is formed, and the through hole is extinct
Edges are filled to form a first conductor pattern and a uniform layer surface
As a result, there is no generation of recesses due to through holes.
The first conductor pattern and the insulator in the through hole.
Thus, the surface of the circuit board is flattened. Flat on this flat surface
A first insulating layer forming a layer surface is formed by printing.
And a second conductor pattern is formed thereon.
And the third insulating layer on the second insulating layer.
Is formed. As a result, the first and second
By laminating the conductor pattern and the first, second and third insulating layers
With the increase in the number of layers, the circuit board
The circuit pattern on the back side can be conducted,
Layering has been realized. Further, the third insulating layer is formed of the second insulating layer.
The printed layer is formed on the same layer as the conductive pattern.
The edge layer and the surface of the insulating layer and the second conductor pattern are marked.
If it is composed of an insulating layer formed by printing,
Can be tanned.

In the method of manufacturing a thick-film multilayer circuit board according to the present invention , the first conductor is formed in the circuit board and its through-hole.
When the pattern is formed, the first conductor pattern is formed on the circuit board.
Unevenness occurs due to holes, and the through hole space
Cause. Therefore, through-hole abortion in the through-hole
Fill the rim with the insulator in the through-hole
The first conductor is formed on a uniform layer surface with the pattern.
The first insulating layer forming the same layer surface as the pattern is
When formed on the surface, the surface of the circuit board becomes flat. So
The second insulating layer formed by printing on the substrate is a flat layer
Form a surface. A second conductor pattern is formed thereon.
You. As a result, the first and second conductor patterns and the first and second conductor patterns
With multi-layering by laminating the second and third insulating layers,
Through the circuit pattern on the front and back sides of the circuit board
It can be conducted, and the air in the through hole passes through
Flat thick multilayer circuit eliminated by insulators in the holes
The substrate is realized. The third insulating layer is a second conductor
Insulating layer that forms the same printing layer as the pattern
Is formed on the surface of this insulating layer and the second conductor pattern.
If the insulating layer is formed by printing, it can be flattened.
Become.

[0010]

FIG. 1 shows an embodiment of a thick film multilayer circuit board according to the present invention, and FIGS. 2 and 3 show an embodiment of a method of manufacturing a thick film multilayer circuit board according to the present invention. As shown in FIG. 2A, a circuit board 2 made of an insulating material such as alumina or ceramic is used for the thick-film multilayer circuit board. Through holes 4a and 4b for conducting between circuits to be formed are formed.

As shown in FIG. 2B and FIG. 4, first conductor patterns 6a, 6b, 6c and 6d are formed on the front and back surfaces of the circuit board 2 by printing a conductor paste or the like. The conductor patterns 6a to 6d are through holes 4a,
4b are connected through the inner wall portion. In the case of this embodiment, the electrical connection between the two circuits is made through the through holes 4a and 4b.

And, in each through hole 4a, 4b,
As shown in FIG. 2C, a resist 8 is filled as an insulator by printing or dispensing.
Each of the through holes 4a and 4b is filled up to form the same plane as the conductor patterns 6a to 6d.

After the through holes 4a and 4b are filled with the resist 8, the portions exposed from the conductor patterns 6a to 6d on the front and back surfaces of the circuit board 2 are shown in FIG.
As shown in FIG . 1, a resist 10a as a first insulating layer ,
10b is installed by printing, this resist 10a,
10b is set to the same thickness as the conductor patterns 6a to 6d. Therefore, the through holes 4a and 4b are filled with the resist 8 and the conductive patterns 6a
Since the portions other than 6d are covered with the resists 10a and 10b, the front and back surfaces of the circuit board 2 form flat surfaces ideal for multilayering.

As shown in FIG. 3E, a resist 1 as a second insulating layer is formed on the front and back surfaces of the circuit board 2.
2a and 12b are formed uniformly, and each of the conductor patterns 6a to 6b
6d of insulation is achieved.

On the surfaces of the resists 12a and 12b,
As shown in FIG. 3F, second conductor patterns 14a, 14b, 14c, and 14d for forming a specific circuit.
Are selectively formed, and resists 16a and 16b as insulating layers having the same thickness as the conductor patterns 14a to 14d are provided in the intervals between the conductor patterns 14a to 14d, as shown in FIG. Formed and conductive patterns 14a to 14
As a result, the unevenness between d and the resists 12a and 12b is compensated, so that the circuit board 2 is flattened. Although not shown, the conductor patterns 14a to 14d and the conductor patterns 6a to 6d formed directly on the circuit board 2 are electrically connected as necessary, and the connection is performed by a conductor pattern penetrating the resists 12a and 12b. Will be

As shown in FIG. 1, a resist 18 serving as an insulating layer is formed on the surface of the circuit board 2 thus multilayered.
a and 18b are formed by printing, and the outer surface of the circuit board 2 is electrically insulated.

As described above, the portions of the through holes 4a and 4b are filled with the insulator to flatten the circuit board 2, and the air in the through holes 4a and 4b is eliminated by the insulator. The resists 12a and 12b, the conductor patterns 14a to 14d, and the like are stacked to form a multilayer circuit.

Further, the unevenness due to the through holes 4a and 4b is compensated by the resist 8, and the circuit board 2 is flattened. Therefore, each of the conductor patterns 14a to 14d has a flat plate shape, and the accuracy of pattern printing is improved, and the reliability is improved. Thus, a circuit pattern having high performance can be obtained.

Although the embodiment has been described with reference to the case where two circuit layers are formed on the front and back sides of the circuit board, that is, four circuit patterns are formed. However, since the circuit board is flattened, five or more layers are formed. The thick-film multilayer circuit board of the present invention is not limited to the four-layer board of the embodiment.

[0020]

According to the thick film multilayer circuit board of the present invention,
You can flatten the circuit board by filling an insulating material in the through holes
Therefore, the thickness of the circuit board is partially reduced by through holes
Unchanged, unevenness caused by conductor pattern
Is flat by forming an insulating layer for each conductor pattern
And the desired number of stacked layers
Through the through-holes on the front and back sides of the circuit board.
Realization of multi-layered front and back surface that enables connection between circuit patterns
A thick multilayer circuit board can be provided.

Further, according to the method of manufacturing a thick film multilayer circuit board of the present invention, the through hole is filled with an insulator to form a through hole.
Flatten the unevenness caused by the
The unevenness caused by the conductor pattern formed on the layer
An insulation layer that insulates conductor patterns between turns
Since it is formed to the same thickness as the
And the conductor pattern can be set to the desired number of layers, and
Air inside the through hole can be eliminated by filling with insulation
Therefore, high-density and reliable thick film multilayer circuit board
Boards can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a thick film multilayer circuit board according to the present invention.

FIG. 2 is a sectional view showing one embodiment of a method of manufacturing a thick film multilayer circuit board according to the present invention.

FIG. 3 is a sectional view showing one embodiment of a method of manufacturing a thick film multilayer circuit board according to the present invention.

FIG. 4 is a partial perspective view showing a circuit board in one embodiment of a method of manufacturing the thick film multilayer circuit board shown in FIG. 2;

[Explanation of symbols]

2 circuit board 4a, 4b through hole 6a, 6b, 6c, 6d first conductor pattern 8 resist (insulator) 14a, 14b, 14c, 14d second conductor pattern 10a, 10b resist (first resist)
Edge layer) 12a, 12b Resist ( second insulating layer)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H05K 3/46

Claims (4)

(57) [Claims] 1. A front and back surface made of an insulating material to form a flat surface.
A circuit board on which a circuit is formed, a single or a plurality of through holes penetrating the front and back surfaces of the circuit board, and a predetermined layer thickness formed by printing on the front and back surfaces of the circuit board
And the inner wall of the through hole
A first conductor pattern for conduction between the circuit by conductors disposed on the surface, is filled in the through hole, the first conductor pattern
An insulator in a through hole forming a uniform layer surface, and the first conductor pattern printed on a surface portion of the circuit board.
A first insulating layer that forms a uniform layer surface with the ground, the first insulating layer, the first conductive pattern, and the space.
Printed on insulator in through hole to form flat layer surface
A second insulating layer to be formed; a second conductive pattern printed on the surface of the second insulating layer ; and a second conductive pattern formed so as to cover the second conductive pattern.
And a third insulating layer formed on the second insulating layer . 2. The method according to claim 1, wherein the third insulating layer is formed on the second conductor path.
Formed by printing on the surface of the second insulating layer from a turn
To form the same layer surface as the second conductor pattern.
An insulating layer for forming a printing surface, the insulating layer and the second conductive layer;
Insulating layer formed by printing on the surface of body pattern
2. The thick-film multilayer circuit board according to claim 1, wherein
Board. 3. A front and back surface made of an insulating material to form a flat surface.
Form a circuit board to form a circuit on the surface
Single or multiple through holes
Forming a conductive layer on the front and back surfaces of the circuit board to a predetermined layer thickness by printing.
And disposed on the inner wall of the through hole
Conductor that conducts between the circuits by the separated conductor
Forming a pattern, and forming a uniform layer surface with the first conductor pattern.
Filling the through hole with an insulator in the hole; and printing the first conductor pattern printed on the surface of the circuit board.
To install a first insulating layer that forms a uniform layer surface
And degree, the first insulating layer, the first conductor pattern and the scan
Printed on insulator in through hole to form flat layer surface
Providing a second insulating layer to be formed, and a second conductor pattern printed on the surface of the second insulating layer.
A step of installing the down, while being formed to cover the second conductor pattern,
Disposing a third insulating layer formed on the second insulating layer;
That process and manufacturing side of the thick-film multi-layer circuit board comprising the
Law. 4. The step of forming the third insulating layer comprises the steps of:
A mark is formed on the surface of the second insulating layer from the second conductor pattern.
And the same as the second conductor pattern
A step of installing an insulating layer that forms a layer surface and forms a printing surface
And a mark on the surface of the insulating layer and the second conductor pattern.
Installing an insulating layer formed by printing.
4. The method for manufacturing a thick film multilayer circuit board according to claim 3, wherein
Construction method.