JP3356650B2 - Printed wiring board and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printed wiring board, and more particularly to a multilayer printed wiring board having an insulating layer and an outer layer pattern formed on an inner layer substrate.

[0002]

2. Description of the Related Art As a method of manufacturing a high-density multilayer printed wiring board, a build-up method has been conventionally known. Hereinafter, a conventional printed wiring board and a method for manufacturing the same will be described with reference to FIG.

FIG. 5 is a schematic cross-sectional view showing a manufacturing process of a conventional printed wiring board. By forming a through hole using a drill or the like on a double-sided printed wiring board having conductor layers provided on both sides of an insulating plate, plating the inside of the through hole, and patterning the conductor layers on both sides, as shown in FIG. An inner substrate 60 is formed. Reference numeral 51 denotes an insulating plate;
a and 52b are inner layer patterns. Reference numeral 55 denotes a through hole, on the inner surface of which a plating layer 55a is formed.
The inner layer patterns 52a and 52b are electrically connected by the through hole 55 having the plating layer 55a.

After filling the inside of the through hole 55 with the filler 55b, a film-shaped photosensitive insulating resin is laminated using a vacuum heat roller or the like so as to cover the inner layer patterns 52a and 52b, and FIG. Insulating layer 53a shown,
53b is formed.

By selectively exposing and developing the insulating layer 53 using a mask, a via hole 57 is formed as shown in FIG.

Next, as shown in FIG. 5D, through through holes 56 are formed by a drill or the like.

Subsequently, the surfaces of the insulating layers 53a and 53b, the inner surface of the via hole 57, and the inner surface of the through-hole 56 are plated to form the conductor layer 5 as shown in FIG.
8a, 58b and plated layer 57a of via hole 57
And the plating layer 56a of the through-hole 56 is formed.

Then, by patterning the conductor layers 58a and 58b, outer layer patterns 54a and 54b are formed as shown in FIG. A multilayer build-up type printed wiring board 50 is completed.

In FIG. 5F, an inner layer pattern 52a is formed.
The inner layer pattern 52b is electrically connected to the inner layer pattern 52b by the plating layer 55a on the inner surface of the through hole 55. The outer layer pattern 54a and the inner layer pattern 52a are electrically connected to each other by a plating layer 57a formed on the inner surface of the via hole 57. The outer layer pattern 54b and the inner layer pattern 52b are electrically connected to each other by a plating layer 57a formed on the inner surface of the via hole 57. The outer layer pattern 56a and the outer layer pattern 56b are electrically connected to each other by the plating layer 56a on the inner surface of the through-hole.
The through-hole 56 can be mounted with an insertion component having a lead pin, and can be electrically connected to a portion other than the printed wiring board 50, for example, a housing or the like by using a screw or the like. .

[0010]

In the above-mentioned printed wiring board, in the manufacturing process, a through hole for connecting the inner layer patterns on both sides of the inner layer substrate to each other and a through hole for connecting the outer layer patterns on both sides to each other, or an insertion part is formed. It is necessary to drill holes in the printed circuit board with through holes for mounting in separate processes, respectively.
At least one drilling step is required before and after the formation of the insulating layer, respectively, which complicates the process.

The present invention has been made in view of the above problems, and eliminates the step of forming through-holes by drilling or the like after the formation of an insulating layer, and provides a printed wiring having through-holes using a build-up method. An object of the present invention is to provide a board and a method for manufacturing the board.

[0012]

According to a first aspect of the present invention, there is provided a printed wiring board, wherein an insulating layer is formed on an inner layer substrate having an inner layer pattern, and an outer layer pattern is formed on the insulating layer. In a printed wiring board having a through hole penetrating the inner layer substrate, the insulating layer, and the outer layer pattern, the through hole is located at a position corresponding to the through hole formed in the inner layer substrate and the through hole of the insulating layer. Do from the via holes formed in the Ri, before
Forming a groove in the insulating layer around the through hole;
Form a plating layer on the inner surface of the part to form an outer layer pattern and inner layer pattern.
And is electrically connected to the terminal .

A printed wiring board according to claim 2 of the present invention.
The method of manufacturing includes the steps of forming a through hole in the inner layer board, the
Arranging an insulating layer on an inner substrate having a through hole formed therein;
And patterning the insulating layer disposed on the inner layer substrate.
At the position of the insulating layer corresponding to the through hole.
Forming a via hole and forming the via hole
Forming an outer layer pattern on the formed insulating layer .

A printed wiring board according to claim 3 of the present invention.
The method of manufacturing the position of the insulating layer corresponding to the through hole
Removing the insulating layer around the via hole formed in
Forming a groove by forming a plating layer on the inner surface of the groove.
Is characterized in that a step of forming.

According to a fourth aspect of the present invention, in the method for manufacturing a printed wiring board, the groove is concentric with the via hole.
It is characterized by being formed in .

[0016]

FIG. 1 is a schematic sectional view of a printed wiring board according to an embodiment of the present invention. Printed wiring board 1
0 denotes inner layer patterns 12a and 12b formed by patterning a conductor layer such as copper formed on the insulating plate 11.
And insulating films 13a and 13b formed on inner layer patterns 12a and 12b, respectively, and outer layer patterns 14a and 14b formed on insulating films 13a and 13b, respectively.

Reference numeral 15 denotes a through hole, on the inner surface of which a plated layer 15a is formed. The inner layer pattern 12a and the inner layer pattern 12b are electrically connected via the plated layer 15a of the through hole 15. The inside of the through hole 15 is filled with a filler 15b such as an epoxy resin.

The through hole 16 provided in the printed wiring board 10 is provided with a through hole 16b penetrating through the inner layer substrate 20, ie, the insulating plate 11 and the inner layer patterns 12a and 12b.
And via holes 16c and 16d formed by removing the insulating film 13a or 13b immediately above the through hole 16b. The through hole 16 is provided with a plating layer 16a on its inner surface.
The outer layer pattern 14a, the outer layer pattern 14b, the inner layer pattern 12a, and the inner layer pattern 12b are electrically connected to each other. Further, by inserting the lead terminal of the insertion component into the through hole 16 and fixing it with solder, the insertion component can be mounted.

Reference numeral 17 denotes a via hole formed by patterning the insulating layers 13a and 13b, the inner surface of which is plated 17a, and the outer layer pattern 14a and the inner layer pattern 1 are formed.
2a and the outer layer pattern 14b and the inner layer pattern 12b.

The through hole 16 is formed on the through hole 16b formed by drilling or the like.
and d. Therefore, the through hole 16b penetrating through the insulating plate 11 and the inner layer patterns 12a and 12b can be formed together with the through hole 15 by using a drill or a laser, and the step of using a drill or a laser again becomes unnecessary. Can be simplified.

FIG. 2 is a schematic sectional view showing a manufacturing process of the printed wiring board of the present invention. Hereinafter, each step will be described with reference to FIGS.

(Step 1) Through holes 15 and through holes 16b are formed in a double-sided copper-clad laminate in which conductor layers are laminated on both sides of an insulating plate.
Is formed, and a plating layer 15a is formed on the inner surfaces of the through hole 15 and the through hole 16b. At this time, the inner surface of the through hole 16b is also plated. The thickness of the plating layer is about 20 μm. . Further, the diameter of the through hole and the through hole is about 0.
5 mm. Subsequently, the conductor layers on both sides are patterned to form inner layer patterns 12a and 12b, and FIG.
Is obtained. Inner layer patterns 12a, 12
b is electrically connected by the plating 15a on the inner surface of the through hole 15. The inner substrate 20 may be a multilayer printed wiring board including an inner circuit in a portion corresponding to the insulating plate 11.

(Step 2) As shown in FIG. 2 (b), after filling the inside of the through hole 15 with a filler 15b such as a resin, both sides of the surface of the double-sided printed wiring board are coated with a film-like photosensitive material. Insulating layers 13a and 13b are formed by laminating the resin using a vacuum heat roller or the like. By forming an insulating layer with a film-like photosensitive resin, the through holes 16 can be formed.
The photosensitive resin does not penetrate deeply into the inside of b, and there is no fear that the resin remains on the inner surface of the hole when patterning is performed.

(Step 3) As shown in FIG. 2C, the insulating layers 13a and 13b of the film-shaped photosensitive resin are selectively exposed to light by using a mask and developed, so that the via holes 17 and , Via holes 16c and 16d are obtained.
After the development process, the insulating layers 13a and 13b are cured by heat treatment or the like. The via holes 16c and 16d are provided just above the through hole 16b and have substantially the same size as the through hole 16b, and communicate with the through hole 16b, respectively. Through hole 16
The through hole 16 is formed by b, the via hole 16c, and the via hole 16d.

(Step 4) As shown in FIG. 2D, plating is applied to the upper surfaces of the insulating layers 13a and 13b, the inner surfaces of the through holes 16 and the inner surfaces of the via holes 17. In addition,
Before the plating step, the surfaces of the insulating layers 13a and 13b may be roughened by a permanganic acid treatment or the like in order to improve the adhesion between the conductor layers 18a and 18b for plating. 1
6a is a plating layer of the through hole 16 and 17a is a plating layer of the through hole 17.

(Step 5) As shown in FIG. 2E, the conductor layers 18a and 18b formed on the insulating layers 13a and 13b are patterned to form outer layer patterns 14a and 14b.
To form a multilayer build-up type printed wiring board 10
Can be obtained.

FIG. 3 is a schematic sectional view showing a reference example . The printed wiring board 10 has an insulating pattern 13a and 12b formed by patterning a conductive layer such as copper formed on the insulating plate 11 and insulating films 13a and 13b formed on the inner layer patterns 12a and 12b, respectively. Membrane 1
It has outer layer patterns 14a and 14b formed on 3a and 13b, respectively.

Numeral 15 denotes a through hole, on the inner surface of which a plating layer 15a is formed. The inner layer pattern 12a and the inner layer pattern 12b are electrically connected via the plated layer 15a of the through hole 15. The inside of the through hole 15 is filled with a filler 15b such as an epoxy resin.

Reference numeral 17 denotes a via hole formed by patterning the insulating layers 13a and 13b, the inner surface of which is plated with 17a, the outer layer pattern 14a and the inner layer pattern 12a.
b, the outer layer pattern 14b and the inner layer pattern 12
b are electrically connected to each other.

The through hole 16 includes a through hole 16b formed by drilling or the like, and via holes 16c and 16d at positions corresponding to the through holes 16b formed by patterning the insulating layers 13a and 13b. The via holes 16c and 16d have a diameter of about 0.2 mm to 0.5 mm, preferably about 0.2 mm, more than the through hole 16b.
It is formed to be about 3 mm larger and has a through through hole 16.
Has step portions 16e and 16f.

The plating layer 16a of the through hole 16 is electrically connected to the inner layer patterns 12a and 12b.
By providing 6e and 16f, the contact area between the plating layer 16a and the inner layer patterns 12a and 12b increases, so that conduction between the plating layers 16a and 16b can be further ensured.

Further, since the via holes 16c and 16d are formed larger than the through holes 16b, errors can be absorbed even if exposure deviation or the like occurs, so that the plating layer in the through holes is completely exposed. A printed wiring board can be obtained.

FIG. 4 is a schematic sectional view showing another embodiment of the printed wiring board of the present invention. The printed wiring board 10
On the inner layer patterns 12a and 12b formed by patterning a conductor layer such as copper formed on the insulating plate 11, the insulating films 13a and 13b formed on the inner layer patterns 12a and 12b, respectively, and on the insulating films 13a and 13b. Outer layer patterns 14a and 14b formed respectively
have.

Reference numeral 15 denotes a through hole, on the inner surface of which a plated layer 15a is formed. The inner layer pattern 12a and the inner layer pattern 12b are electrically connected via the plated layer 15a of the through hole 15. The inside of the through hole 15 is filled with a filler 15b such as an epoxy resin.

Reference numeral 17 denotes a via hole formed by patterning the insulating layers 13a and 13b, the inner surface of which is plated 17a, and the outer layer pattern 14a and the inner layer pattern 1 are formed.
2a and the outer layer pattern 14b and the inner layer pattern 12b.

The through hole 16 is formed between the through hole 16b formed by drilling or the like and the insulating layers 13a and 13b.
And via holes 16c and 16d at positions corresponding to the through holes 16b formed by patterning. Further, a plating layer 16a is formed on the inner surface of the through hole 16, and the outer layer patterns 14a, 14a are formed.
b, the inner layer patterns 12a and 12b are conducted.

By removing the insulating layers 13a and 13b concentrically with the through via hole 16, a concentric groove 19a is formed. A plating layer 19a is formed on the inner surface of the groove 19, and the outer layer pattern 14a and the inner layer pattern 12 are formed.
a, the outer layer pattern 14b and the inner layer pattern 1
2b are electrically connected to each other.

By the groove 19 and the plating layer 19a, the reliability of conduction between the outer layer pattern 14a and the inner layer pattern 12a and between the outer layer pattern 14b and the inner layer pattern 12b can be improved. In addition, a printed wiring board having an improved conductor adhesion strength between the outer layer pattern and the insulating layer after the component is inserted into the through-hole 16 and soldered can be obtained.

[0039]

According to the printed wiring board of the first aspect of the present invention, an insulating layer is formed on an inner substrate having an inner layer pattern, and an outer layer pattern is formed on the insulating layer. A printed wiring board having a through hole penetrating a substrate, the insulating layer, and the outer layer pattern, wherein the through hole is a position corresponding to the through hole formed in the inner layer substrate and the through hole of the insulating layer. Do Ri, the through scan from the via holes formed in
A groove is formed in the insulating layer around the hole and the inner surface of the groove is formed.
Forming a plating layer to lead the outer layer pattern and inner layer pattern
It is characterized by passing through , and it is possible to eliminate the step of forming through-holes by drilling or the like after forming the insulating layer, and to simplify the process, thereby efficiently manufacturing a multilayer printed wiring board. Can be. further,
Conduct more reliably between the outer layer pattern and the inner layer pattern.
Can be.

[0040]

[0041]

According to the method of manufacturing a printed wiring board according to the second aspect of the present invention, a step of forming a through hole in the inner substrate, and disposing an insulating layer on the inner substrate in which the through hole is formed. a step, a step of forming a via hole in <br/> position of the insulating layer with patterning the insulating layer disposed on the inner layer board, corresponding to the previous SL through holes, the via-hole
Forming an outer layer pattern on the insulating layer on which the insulating layer is formed, thereby eliminating the step of forming through-holes by drilling or the like after forming the insulating layer, thereby simplifying the process. Therefore, a multilayer printed wiring board can be efficiently manufactured. Of the present invention
A method for manufacturing a printed wiring board according to claim 3.
For example, it is formed at the position of the insulating layer corresponding to the through hole.
The insulating layer around the via hole was removed to form a groove.
Forming a plating layer on the inner surface of the groove.
And the groove is formed in the via.
Characterized by being formed concentrically with the hole
Yes, outer layer pattern and inner layer depending on groove and plating layer
The reliability of conduction with the pattern can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view illustrating a manufacturing process of the printed wiring board of the present invention.

FIG. 3 is a schematic sectional view showing a reference example .

FIG. 4 is a schematic sectional view showing another embodiment of the printed wiring board of the present invention.

FIG. 5 is a schematic cross-sectional view showing a manufacturing process of a conventional printed wiring board.

[Explanation of symbols]

10 printed wiring board 11 insulating plates 12a, 12b the inner layer patterns 13a, 13b insulating layers 14a, 14b outer layer pattern 16 through through hole 16a plated layer 16b through holes 16c, 16 d via holes 16e, 16f stepped portion 19 groove 19a plating layer 20 inner layer board

Claims (4)

(57) [Claims] An insulating layer is formed on an inner substrate having an inner layer pattern, an outer layer pattern is formed on the insulating layer, and a through hole penetrating the inner layer substrate, the insulating layer, and the outer layer pattern is formed. in the printed wiring board having said through through-holes, the Ri Do and a through-hole formed in an inner layer substrate and via holes formed at positions corresponding to the through hole of the insulating layer, insulation around the through through-hole Forming a groove in the layer;
A plating layer is formed on the inner surface of the groove to form an outer layer pattern and inner layer pattern.
A printed wiring board characterized by being electrically connected to the circuit board. 2. A process of forming a through hole in the inner layer substrate, patterning the step of disposing an insulating layer on an inner layer substrate on which the through holes are formed, an insulating layer disposed on the inner layer board with, before Symbol forming a via hole in a position of the insulating layer corresponding to the through-hole, printed wiring, which comprises a step of forming an outer layer pattern on the via hole is formed an insulating layer Plate manufacturing method. 3. A method for manufacturing a printed wiring board according to claim 2.
In the method, a bar formed at the position of the insulating layer corresponding to the through hole is formed.
The insulating layer around the ear hole is removed to form a groove.
And a step of forming a plating layer on the inner surface of the groove.
A method for manufacturing a printed wiring board, which is a feature. 4. A method for manufacturing a printed wiring board according to claim 3.
In the method, the groove is formed concentrically with the via hole.
A method for manufacturing a printed wiring board, comprising: