JPH11121930A - Method for manufacturing multilayer printed wiring board - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a multilayer printed wiring board having an interlayer connection structure with high wiring density and high connection reliability. SOLUTION: A conductor layer 22 having a terminal 22a is formed on an insulating substrate 21, and the insulating layer 2 is covered by the conductor layer 22.
Form 3 A conductor layer having a land is formed on the insulating layer, and a photosensitive resin layer is formed to cover the conductor layer. An insertion hole 26a is formed in the photosensitive resin layer 25 by photolithography, and a portion of the land 24a and the insulating layer 23 surrounded by the land 24a are formed.
To expose. The exposed insulating layer 23 is irradiated with laser light by using the exposed land 24a as a mask to remove the
6b is formed. The insertion holes 26a and 26b form the insertion holes 26 for via holes. A conductor layer having terminals is formed on the photosensitive resin layer 25, and at the same time, a conductor covering the surface of the insertion hole 26 is formed.

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 multilayer printed wiring board by a so-called build-up method, and more particularly to a method of manufacturing a multilayer printed wiring board having a so-called via hole, which connects different conductor layers to each other. About.

[0002]

2. Description of the Related Art FIGS. 6 and 7 are sectional views showing stepwise printed wiring boards 10a to 10g for explaining a method of manufacturing a multilayer printed wiring board by a build-up method as a conventional technique. First, as shown in FIG. 6A, conductor layers 2 are formed on both front and back surfaces of an insulating substrate 1 made of an insulating resin, and a printed wiring board 10a is formed. Conductor layer 2
Consists of a conductor pattern formed by an etching method or the like. The conductor layer 2 has terminals 2a for connecting different conductor layers to each other.

[0006] Next, as shown in FIG. 6 (B), insulating layers 3 made of an insulating resin are formed on both surfaces of the insulating substrate 1 so as to cover the conductor layer 2, thereby forming a printed wiring board 10 b. Is done. The insulating layer 3 is formed by a full-screen printing method using screen printing, a method of attaching a resin film coated with a film-like semi-cured resin or an adhesive, or the like.
As the insulating resin, a material conventionally used as a wiring board material such as an acrylic resin, an epoxy resin, or a polyimide resin is used.

[0006] Next, as shown in FIG. 6 (C), through holes 4 for via holes are formed in predetermined regions of the insulating layer 3, and a printed wiring board 10 c is formed. A part of the terminal 2a is exposed by the insertion hole 4. The insertion hole 4 is formed by irradiating a laser beam. The laser beam to be used is selected depending on the insulating resin material. For example, a general carbon dioxide laser or a YAG (yttrium aluminum garnet) laser is used.

[0005] Next, as shown in FIG. 6 (D), the printed wiring board 10 covering the exposed insulating layer 3 and the terminal 2 a.
c, conductors 5 are respectively formed on the front and back surfaces of the printed wiring board 1.
0d is created. The conductor 5 is formed by a plating method.
Copper is used as a conductor material to be used.

Next, as shown in FIG. 7A, the conductor 5 is selectively corroded by an etching method to form a conductor layer 6 composed of a conductor pattern, and a printed wiring board 10e is formed. The formed conductor layer 6 has a land 6a which is a terminal for connecting different conductor layers to each other.
At the same time as the conductor layer 6, a connection conductor 6b for connecting the terminal 2a and the land 6a is formed so as to cover the surface of the insertion hole 4, and thus a via hole for connecting the conductor layers 2 and 6 to each other is formed. It is formed.

Next, as shown in FIG. 7B, an insulating layer 7 is formed on the insulating layer 3 so as to cover the conductor layer 6, and a printed wiring board 10f is formed. The insulating layer 7 is formed in the same manner as the insulating layer 3.

Next, as shown in FIG. 7C, a conductor layer 9 is formed, and a printed wiring board 10g is formed. The conductor layer 9 is formed in the same manner as the conductor layer 6. Further, similarly to the above, the terminal 6c of the conductor layer 6 and the conductor layer 9 are formed by the via hole using the insertion hole 8 formed in the insulating layer 7.
Are connected to each other by the connecting conductor 9b.

Such insulating layers 3 and 7 and conductor layers 6
9 is repeated, and finally, the outermost layer is subjected to solder resist or silk printing to complete a multilayer printed wiring board. Although FIGS. 7A to 7C show only one surface of the insulating substrate 1, the other surface is formed in the same manner.

An example in which the insertion holes 4 and 8 are formed by irradiating a laser beam as described above is disclosed in, for example, JP-A-9-1864.
No. 60 is disclosed. Also, the insertion holes 4 and 8 are
In addition to the above-described formation by laser light irradiation, it can be formed by a photolithography method or a physical polishing method. In the photolithography method, an interlayer insulating layer is formed of a photosensitive resin, the resin is selectively irradiated with light, and an uncured resin is removed to form an insertion hole. In the physical polishing method, an interlayer insulating layer is formed. Is polished by sandblasting or the like to form an insertion hole.

In the photolithography method, a large number of insertion holes can be formed in one process, the processing speed is high, the manufacturing cost is low, and the mass productivity is excellent. Poor density. The same applies to the physical polishing method. On the other hand, the laser beam irradiation method is suitable for forming an insertion hole having a small diameter and enables high-density wiring. However, since the insertion holes are formed one by one, the processing speed is low and the manufacturing cost is high. Inferior in mass productivity. In the present circumstances,
Photolithography is used relatively frequently.

[0012]

In the manufacturing method shown in FIGS. 6 and 7, since the insertion holes are formed for each layer, the history of the insertion holes formed in the lower layer affects the upper layer, and the surface of the printed wiring board has A recess is formed. This recess has an adverse effect on the formation of the upper conductor layer, and hinders the stable formation of a photosensitive resin for patterning the conductor layer. Therefore, it is not possible to form a conductor pattern on a via hole or to form a via hole at the same position in each layer, and it is necessary to form an upper conductor layer and a via hole avoiding a lower via hole, and to increase the wiring density. Decrease.

Further, according to the laser beam irradiation method, it is possible to collectively form a through hole for a via hole in two or more insulating layers. The pattern of each conductor layer must be accurately positioned and formed, and the laser beam must be accurately irradiated through the upper insulating layer in the land of the lower insulating layer hidden by the upper insulating layer. If the positioning accuracy of the conductor pattern is inferior, the connection reliability decreases. For example, referring to FIG. 8, when connecting three conductor layers to each other, lands 6a are formed by accurately positioning lands 6a with respect to terminals 2a.
It is necessary to accurately irradiate the insulating layer 3 in the hidden land 6a with the laser light. Further, in order to obtain high connection reliability, it is necessary to remove the insulating layer 7 so that the side surface of the land 6a is surely exposed. However, the insulating resin tends to remain on the side surface of the land 6a substantially parallel to the irradiation direction of the laser beam, and it is not easy to reliably expose the side surface of the land. In addition, the height of the land is only a few tens of μm, and connection failure is likely to occur due to various factors such as dust generated during removal and plating failure.

Further, when the through holes having different diameters are formed by using any one of a laser beam irradiation method, a photolithography method and a physical polishing method, it is not optimal in terms of mass productivity or wiring density. Further, regardless of which method is used, if the insulating resin remains in the insertion hole, plating failure occurs, and connection reliability decreases.

An object of the present invention is to provide a method of manufacturing a multilayer printed wiring board having an interlayer connection structure having high wiring density and high connection reliability.

[0016]

According to the present invention, a plurality of conductor layers are laminated via an insulating layer, and different conductor layers are electrically connected to each other by using insertion holes penetrating the insulating layer between the conductor layers. In the method for manufacturing a multilayer printed wiring board having an interlayer connection structure, the insulating layer is made of a photosensitive resin, and selectively one of a laser beam irradiation method and a photolithography method according to the diameter of the insertion hole. A method for manufacturing a multilayer printed wiring board, comprising a step of forming an insertion hole in an insulating layer using the same.

According to the present invention, the insertion hole formed in the insulating layer made of a photosensitive resin for the interlayer connection structure is formed by a method according to the diameter. Therefore, the wiring density can be increased by using the laser light irradiation method, and the mass productivity can be increased by using the photolithography method.

Further, according to the present invention, the diameter of the insertion hole is 0.1
0.15 m
When m is exceeded, a photolithography method is used.

According to the present invention, each method is properly used as described above according to the diameter of the insertion hole. Therefore, a multilayer printed wiring board having a high wiring density can be manufactured with excellent mass productivity.

The present invention also relates to a method for manufacturing a multilayer printed wiring board having a plurality of laminated conductor layers and an interlayer connection structure for electrically connecting different conductor layers to each other. Forming a conductive layer having a land on the insulating layer; forming a conductive layer having a land on the insulating layer; and forming a photosensitive layer covering the land on the insulating layer. Forming a resin layer; removing the photosensitive resin layer by photolithography so as to expose the land and an insulating layer surrounded by the land to form an insertion hole; And removing the insulating layer by irradiating a laser beam to form an insertion hole.

According to the present invention, a conductor layer is formed on an insulating substrate, a conductor layer having a land is formed via an insulating layer covering the conductor layer, and a photosensitive resin layer covering the land is formed. Removing the photosensitive resin layer by a photolithography method so that the lands and an insulating layer surrounded by the lands are exposed, and removing the exposed insulating layers by irradiating a laser beam; A through hole for an interlayer connection structure can be formed by using a method and a laser beam irradiation method.

Further, the present invention is characterized in that, in the step of removing the insulating layer by irradiating the laser beam, the exposed land is used for positioning the laser beam.

According to the present invention, the land exposed together with the insulating layer by the photolithography method can be used for determining the irradiation position of the laser beam, and thereby the irradiation position can be accurately and easily determined. Since the insertion hole can be formed at an accurate position, an interlayer connection structure with high connection reliability can be provided.

Further, the invention is characterized in that in the step of removing the insulating layer by laser light irradiation, the exposed land is used as a mask to irradiate laser light.

According to the present invention, it is possible to irradiate a laser beam to an accurate position by using a land exposed together with an insulating layer by photolithography as a mask. Since the insertion hole can be formed at an accurate position in this manner, an interlayer connection structure with high connection reliability can be provided.

Further, in the present invention, in the step of removing the insulating layer by laser light irradiation, the exposed land surface is also irradiated with laser light.

According to the present invention, the surface of the land exposed together with the insulating layer by the photolithography method is also irradiated with the laser beam, whereby the photosensitive resin remaining on the land surface and not completely removed by the photolithography method can be surely removed. Can be removed. Therefore, an interlayer connection structure with high connection reliability can be provided.

Further, according to the present invention, after the insulating layer is removed by laser light irradiation, a conductor layer is formed on the exposed photosensitive resin layer, and at the same time, the insertion layer formed by photolithography and laser light irradiation is used. Forming a conductor on a side surface of the hole.

According to the present invention, after forming an insertion hole for an interlayer connection structure, a conductor layer is formed on the photosensitive resin layer. At the same time, a conductor is formed on the side surface of the insertion hole,
Different conductor layers are connected to each other via the lands. Since the conductor is formed not only on the side surface of the land but also on the surface thereof, the conductor layers can be reliably connected to each other.

Further, the present invention is characterized in that the conductor layer on the exposed photosensitive resin layer and the conductor on the side surface of the insertion hole are formed by plating.

According to the present invention, the conductor layer on the photosensitive resin layer after the formation of the insertion hole and the conductor on the side surface of the insertion hole can be simultaneously formed by plating. Therefore, these members can be formed relatively easily.

Further, the present invention includes a plurality of steps of forming the conductor layer having the lands, wherein the diameter of the insulating layer surrounded by the lands of each layer increases toward the upper layer.

According to the present invention, when a plurality of conductor layers having lands are formed, generally, in a conductor layer formed by lamination, the positional deviation from the lowermost layer becomes larger toward the upper layer. According to the present invention, since the diameter of the insulating layer surrounded by the lands of each layer is selected to be larger toward the upper layer, the above-described positional shift can be tolerated, and thus a multilayer printed wiring board having high connection reliability can be provided.

[0034]

1 and 3 show a first embodiment of the present invention.
It is sectional drawing which shows stepwise the printed wiring board 29a-29f for demonstrating the manufacturing method of the multilayer printed wiring board by the build-up method which is embodiment. FIG. 2 shows the printed wiring board 2.
It is a perspective view which shows 9b. In the present embodiment, the common name is “2”.
A multilayer printed wiring board called the “+ 2 + 2” type will be described. The multilayer printed wiring board has a total of six conductive layers in which two conductive layers are formed on both sides of a printed wiring board 29a having conductive layers formed on both sides by a build-up method. 1 (B) to FIG.
(E) and FIG. 3 show only one surface of the insulating substrate 21, but the other surface is formed in the same manner.

First, as shown in FIG. 1A, a conductive layer 22 is formed on both front and back surfaces of an insulating substrate 21 made of insulating resin.
Are formed, and the printed wiring board 29a is created.
The conductor layer 22 is made of a conductor pattern formed by an etching method or the like, and has terminals 22a for connecting different conductor layers to each other.

Next, as shown in FIG. 1B, an insulating layer 23 is formed on the insulating substrate 21 so as to cover the conductor layer 22. The insulating layer 23 is formed by a full-screen printing method using screen printing or a method of attaching a resin film coated with a film-like semi-cured resin or an adhesive. As the insulating resin to be used, a material conventionally used as a wiring board material such as an acrylic resin, an epoxy resin, or a polyimide resin is used. Further, the conductor layer 24 is formed on the insulating layer 23 and the printed wiring board 29
b is created. The conductor layer 24 is made of a conductor pattern formed by patterning a conductor such as copper formed by a plating method by an etching method or the like, and has a land 24a for connecting different conductor layers to each other. The land 24a is an annular conductor having a predetermined land width as shown in FIG. 2, and the diameter W of the insulating layer 23 surrounded by the land 24a is set to a predetermined length. The diameter W is selected to be a length necessary as a mask when irradiating a laser beam to be described later and a length necessary to maintain high reliability of interlayer connection.

Next, as shown in FIG. 1C, a photosensitive resin layer 25 is formed on the insulating layer 23 so as to cover the conductor layer 24, and a printed wiring board 29c is formed.

Next, as shown in FIG. 1D, an insertion hole 26a is formed in a predetermined area of the photosensitive resin layer 25,
The printed wiring board 29d is created. A part of the land 24a on the inner side and the land 2 are formed by the insertion hole 26a.
The insulating layers 23 surrounded by 4a are respectively exposed.
The insertion hole 26a is formed by a known photolithography method. Specifically, a mask having a pattern of the insertion holes 26a is arranged on the photosensitive resin layer 25, and light is irradiated through the mask. The photosensitive resin layer 25 can insolubilize or solubilize the light-irradiated region depending on the form of the material to be used, and remove the resin in a predetermined region by developing. Thus, the insertion hole 26a is formed.

Next, after the photosensitive resin is cured, FIG.
As shown in (E), the exposed insulating layer 23 is irradiated with a laser beam, and the insulating layer 23 is removed.
Is formed, and the printed wiring board 29e is created. At this time, the exposed land 24a is used for determining the irradiation position of the laser beam. In particular, laser light is irradiated using the exposed land 24a as a mask. Therefore, the irradiation position of the laser beam can be accurately and easily determined,
Part of the terminal 22a can be reliably exposed.
Further, it is preferable to irradiate the exposed surface of the land 24a with a laser beam, whereby the insulating resin remaining on the surface of the land 24a can be surely removed. The insertion holes 26a and 26b allow the insertion holes 2 for via holes to be formed.
6 are configured. The laser beam used is selected depending on the insulating resin material. For example, a general carbon dioxide laser or a YAG laser is used.

Next, a conductor made of copper or the like is formed on the exposed surface of the photosensitive resin layer 25, the land 24a, the insulating layer 23, and the terminal 22a, that is, the surface of the printed wiring board 29e by plating, and the conductor is etched. As shown in FIG. 3, the conductor layer 27 is formed of a conductor pattern by selective etching, and a printed wiring board 29f is formed. The formed conductor layer 27 has terminals 27a for connecting different conductor layers to each other. At the same time as the conductor layer 27, a connection conductor 27b for interconnecting the terminals 22a, 27a and the lands 24a is formed so as to cover the surface of the insertion hole 26, thereby forming a via hole. Finally, the outermost layer is subjected to solder resist or silk printing to complete a multilayer printed wiring board.

As described above, according to the first embodiment, the conductor layer 22 having the connection terminals 22 a is formed on the insulating substrate 21, and the land 24 a is provided via the insulating layer 23 covering the conductor layer 22. A conductor layer 24 is formed, and the land 24 is formed.
a is formed to cover the land 24a.
The photosensitive resin layer 25 is removed by photolithography so that the insulating layer 23 surrounded by the land 24a is exposed, and the exposed insulating layer 23 is removed by irradiating a laser beam. An insertion hole 26 for a via hole can be created. Further, the conductor layer 27 is formed on the photosensitive resin layer 25, and at the same time, the connection conductor 27b is formed.

According to such a manufacturing method, the insertion holes 26 for the via holes can be formed collectively after the formation of the insulating layer 23 and the photosensitive resin layer 25, and the history of the insertion holes formed in the lower layer is recorded in the upper layer. The recess is not formed on the surface of the printed wiring board due to adverse effects. Therefore, a photosensitive resin for patterning the conductor layer can be formed stably, and a conductor pattern can be formed on the via hole and a via hole can be formed in the same place of each layer by overlapping.
The wiring density can be increased.

Further, by using the exposed land 24a for positioning the laser beam, the laser beam irradiation position for the insertion hole 26b can be accurately and easily determined. In particular, the terminal 22a can be reliably exposed by irradiating a laser beam using the exposed land 24a as a mask. In this manner, the insertion hole 26 can be formed at an accurate position, and thus a via hole with high connection reliability can be formed.

The exposed surface of the land 24a is also irradiated with a laser beam, whereby the photosensitive resin remaining on the surface of the land 24a can be reliably removed. Therefore, a via hole with high connection reliability can be formed.

The conductor layer 27 on the photosensitive resin layer 25
And the connection conductor 27b are formed simultaneously by plating. Therefore, these members can be formed easily and in a short time.

In this embodiment, the example of the multilayer printed wiring board of the "2 + 2 + 2" type has been described. However, the present invention is connected to each other when forming a via hole for connecting two or more conductor layers to each other. Any structure as long as the lands of the second conductor layer from the outermost layer of the conductor layers are exposed by photolithography and the insulating layer surrounded by the lands is removed by laser light irradiation. May be applied to the multi-layer printed wiring board, and the same effects as those of the present embodiment can be obtained.

In this embodiment, the terminals 22a, 27
Although the example of the via hole connecting all of the land 22a and the land 24a has been described, the terminal 22a and the land 24a are
Alternatively, an example of a via hole connecting the land 24a and the terminal 27a also belongs to the scope of the present invention.

FIG. 4 is a sectional view showing stepwise printed wiring boards 33a to 33c for explaining a method of manufacturing a multilayer printed wiring board by a build-up method according to a second embodiment of the present invention. In the present embodiment, a multilayer printed wiring board called a “1 + 2 + 1” type will be described, but the structure is not limited to this. The multilayer printed wiring board has a total of four conductive layers in which one conductive layer is formed on each side by a build-up method on both sides of a printed wiring board having conductive layers formed on both sides. The first
Members similar to those of the printed wiring board 29f of the embodiment are denoted by the same reference numerals.

First, as shown in FIG. 4A, a conductor layer 22 is formed on each of the front and back surfaces of an insulating substrate 21. The conductor layer 22 made of a conductor pattern has terminals 22a and 22b for connecting different conductor layers to each other. Further, a photosensitive resin layer 30 is formed on the insulating substrate 21 so as to cover the conductor layer 22, and a printed wiring board 33a is formed.

Next, as shown in FIG. 4B, a relatively large diameter insertion hole 3 is formed in a predetermined area of the photosensitive resin layer 30.
1 is formed by the photolithography method, and the printed wiring board 33b is created. The terminal 2 is inserted through the insertion hole 31.
Part of 2a is exposed.

Next, after the photosensitive resin is cured, FIG.
As shown in FIG. 2C, a relatively small diameter insertion hole 32 is formed in a predetermined area of the photosensitive resin layer 30 by irradiating a laser beam, and a printed wiring board 33c is formed. A part of the terminal 22b is exposed by the insertion hole 32.

Next, a conductor such as copper is formed on the exposed photosensitive resin layer 30 and the terminals 22a and 22b by plating, and the conductor is selectively corroded by etching to form a conductor layer comprising a conductor pattern. Is formed. The conductor layer is a terminal for connecting different conductor layers to each other, and has terminals connected to the terminals 22a and 22b. At the same time as the conductor layer, connection conductors for connecting the terminals to each other are formed to cover the surfaces of the insertion holes 31 and 32, thereby forming via holes.
Finally, the outermost layer is subjected to solder resist or silk printing to complete a multilayer printed wiring board.

As described above, according to the second embodiment, when the insertion holes 31 and 32 having different diameters for the via holes are provided, the insertion holes 31 and 32 are formed by the photolithography method and the laser beam according to the diameter. It is formed by any one of irradiation methods. In particular, when the diameter of the insertion hole is 0.15 mm or less, the laser beam irradiation method is used.
When it exceeds 15 mm, it is preferable to use a photolithography method. Therefore, the diameter of the insertion hole is not carelessly increased, and the wiring density can be increased. According to such a manufacturing method, a multilayer printed wiring board having a high wiring density can be manufactured in a large amount in a short time, and the manufacturing cost can be reduced.

The diameter for selectively using the method for forming the through-hole is not limited to the above-mentioned value, but is appropriately selected depending on the specifications of the wiring board and the hole diameter distribution.

FIG. 5 is a sectional view showing a printed wiring board 37 for explaining a method of manufacturing a multilayer printed wiring board by a build-up method according to a third embodiment of the present invention. In the present embodiment, a multilayer printed wiring board called “3 + 2 + 3” type will be described, but the structure is not limited to this. The multilayer printed wiring board has a total of 8 printed conductor boards each having a conductor layer formed on both sides, and three conductor layers each formed on both sides thereof by a build-up method.
And a conductor layer. Although only one surface of the insulating substrate 21 is shown in FIG. 5, the other surface is formed in the same manner. The same members as those of the printed wiring board 29f of the first embodiment are denoted by the same reference numerals.

First, a conductor layer 22 is formed on an insulating substrate 21. The conductor layer 22 made of a conductor pattern has terminals 22a for connecting different conductor layers to each other. Further, an insulating layer 23 is formed on the insulating substrate 21 so as to cover the conductor layer 22. Next, the conductor layer 24 is formed on the insulating layer 23. The conductor layer 24 made of a conductor pattern has lands 24a for connecting different conductor layers to each other. The diameter of the insulating layer 23 surrounded by the land 24a has a predetermined length W1. Further, an insulating layer 34 is formed on the insulating layer 23 so as to cover the conductor layer 24. Next, the conductor layer 27 is formed on the insulating layer 34.
Is formed. The conductor layer 27 made of a conductor pattern has lands 27c for connecting different conductor layers to each other. The diameter of the insulating layer 34 surrounded by the land 27c has a predetermined length W2 (> W1). Further, a photosensitive resin layer 35 is formed on the insulating layer 34 so as to cover the conductor layer 27.

Next, an insertion hole 36 is formed in a predetermined region of the photosensitive resin layer 35 by photolithography, and a printed wiring board 37 is formed. The insulating layer 34 surrounded by a part of the land 27a and the land 27c is exposed by the insertion hole 36. Next, after the photosensitive resin is cured, a predetermined region of the exposed insulating layer 34 is irradiated with laser light to form an insertion hole. At least a part of the terminal 22a is exposed by the insertion hole. Also, a part of the land 24a can be exposed. Also, a part of the terminal 22a can be exposed.

Next, the exposed photosensitive resin layer 35, lands 27c and 24a, insulating layers 34 and 23, and terminal 22
A conductor such as copper is formed on a by a plating method, and the conductor is selectively corroded by an etching method to form a conductor layer composed of a conductor pattern. The conductor layer is a terminal for connecting different conductor layers to each other, and has terminals connected to the terminal 22a and the lands 24a and 27c. At the same time as the conductor layer, a connection conductor for connecting the terminals to each other is formed to cover the surface of the insertion hole 36, thereby forming a via hole. Finally, the outermost layer is subjected to solder resist or silk printing to complete a multilayer printed wiring board.

When a plurality of conductor layers having lands are formed, generally, in a conductor layer formed by lamination, the positional shift with respect to the lowermost layer becomes larger toward the upper layer. According to the third embodiment, the lands 24a of the conductor layers 24 and 27,
27c, the diameters W1,
W2 is largely selected toward the upper layer. That is, W2
> W1, the above-described positional deviation can be allowed. Therefore, a multilayer printed wiring board with high reliability of interlayer connection can be produced.

The first embodiment may be combined with the second embodiment, or the third embodiment may be combined. Further, all of the first to third embodiments may be implemented in combination.

[0061]

As described above, according to the present invention, the insertion hole for the interlayer connection structure is formed by one of the laser beam irradiation method and the photolithography method according to the diameter. In addition, a multilayer printed wiring board having a high wiring density can be manufactured with excellent mass productivity.

Further, according to the present invention, the diameter of the insertion hole is equal to 0.
A multilayer printed wiring board having a high wiring density can be manufactured with high mass productivity by using a laser beam irradiation method when the thickness is 15 mm or less and using a photolithography method when exceeding 15 mm.

According to the present invention, the photosensitive resin layer is removed by photolithography to expose the land and the insulating layer surrounded by the land, and the insulating layer is removed by irradiating a laser beam. In this way, an insertion hole for an interlayer connection structure can be created.

Further, according to the present invention, the irradiation position can be accurately and easily determined by using the land exposed together with the insulating layer by the photolithography method for positioning the laser beam. With the insertion hole formed in this way, a highly reliable interlayer connection structure can be realized.

Further, according to the present invention, it is possible to irradiate a laser beam to a precise position using a land exposed together with an insulating layer by photolithography as a mask. With the insertion hole formed in this way, a highly reliable interlayer connection structure can be realized.

Further, according to the present invention, the surface of the land exposed together with the insulating layer by the photolithography method is irradiated with the laser beam, whereby the insulating layer remaining on the land surface can be surely removed. With the insertion hole formed in this way, a highly reliable interlayer connection structure can be realized.

Further, according to the present invention, after forming the insertion hole for the interlayer connection structure, the conductor layer is formed on the photosensitive resin layer, and at the same time, the conductor is formed on the side surface of the insertion hole. Different conductor layers can be connected to each other by the conductor. Thus, a multilayer printed wiring board having an interlayer connection structure with high connection reliability can be produced.

According to the present invention, the conductor layer and the conductor can be simultaneously formed by plating. Therefore, these members can be formed relatively easily.

Further, according to the present invention, even when a plurality of conductor layers having lands are formed, the diameter of the insulating layer surrounded by the lands of each layer is selected to be larger toward the upper layer. , A multilayer printed wiring board with high performance can be produced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing stepwise printed wiring boards 29a to 29e for describing a method for manufacturing a multilayer printed wiring board according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a printed wiring board 29b for describing a method for manufacturing a multilayer printed wiring board according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a printed wiring board 29f for describing a method for manufacturing a multilayer printed wiring board according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing stepwise printed wiring boards 33a to 33c for describing a method for manufacturing a multilayer printed wiring board according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a printed wiring board 37 for describing a method for manufacturing a multilayer printed wiring board according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing stepwise printed wiring boards 10a to 10d for describing a conventional method for manufacturing a multilayer printed wiring board.

FIG. 7 is a cross-sectional view showing stepwise printed wiring boards 10e to 10g for describing a conventional method for manufacturing a multilayer printed wiring board.

FIG. 8 is a cross-sectional view showing a printed wiring board when three conductor layers are connected to each other.

[Explanation of symbols]

 21 Insulating substrate 22, 24, 27 Conductive layer 22a, 22b, 27a Terminal 23, 34 Insulating layer 24a, 27c Land 25, 30, 35 Photosensitive resin layer 26, 26a, 26b, 31, 32, 36 Insertion hole 27b Connection Conductors 29a-29f, 33a-33c, 37 Printed wiring board

Claims (9)

[Claims] 1. A multilayer printed wiring having an interlayer connection structure in which a plurality of conductor layers are stacked via an insulating layer, and different conductor layers are electrically connected to each other using insertion holes penetrating the insulating layer between the conductor layers. In the method of manufacturing a plate, the insulating layer is made of a photosensitive resin, and selectively uses one of a laser beam irradiation method and a photolithography method according to the diameter of the insertion hole, and the insertion hole is formed in the insulating layer. Forming a multilayer printed wiring board. 2. The multilayer printed wiring according to claim 1, wherein a laser beam irradiation method is used when the diameter of the insertion hole is 0.15 mm or less, and a photolithography method is used when the diameter exceeds 0.15 mm. Plate manufacturing method. 3. A method for manufacturing a multilayer printed wiring board having a plurality of stacked conductor layers and an interlayer connection structure for electrically connecting different conductor layers to each other, wherein the conductor layer is formed on an insulating substrate. A step of forming an insulating layer covering the conductor layer on the insulating substrate; a step of forming a conductor layer having a land on the insulating layer; and a photosensitive resin layer covering the land on the insulating layer. Forming, forming a through hole by removing the photosensitive resin layer by photolithography so that the land and the insulating layer surrounded by the land are exposed; and forming an insulating hole surrounded by the exposed land. Removing the layer by irradiating a laser beam to form an insertion hole. 4. The method according to claim 3, wherein in the step of removing the insulating layer by irradiating the laser beam, the exposed land is used for positioning the laser beam. 5. The method for manufacturing a multilayer printed wiring board according to claim 3, wherein in the step of removing the insulating layer by laser beam irradiation, the exposed land is used as a mask to irradiate the laser beam. 6. The method for manufacturing a multilayer printed wiring board according to claim 3, wherein in the step of removing the insulating layer by laser light irradiation, the exposed land surface is also irradiated with laser light. 7. After the insulating layer is removed by irradiating a laser beam, a conductor layer is formed on the exposed photosensitive resin layer,
4. The method for manufacturing a multilayer printed wiring board according to claim 3, further comprising a step of simultaneously forming a conductor on a side surface of said insertion hole formed by a photolithography method and a laser beam irradiation method. 8. The method for manufacturing a multilayer printed wiring board according to claim 7, wherein the conductor layer on the exposed photosensitive resin layer and the conductor on the side surface of the insertion hole are formed by plating. 9. The multilayer according to claim 3, comprising a plurality of steps of forming the conductor layer having the lands, wherein the diameter of the insulating layer surrounded by the lands of each layer increases toward the upper layer. Manufacturing method of printed wiring board.