JPH09199855A - Manufacture of multilayer interconnection board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to be able to make a multilayer interconnection board correspond fully to a high-density mounting. SOLUTION: Through holes 52A, 52B and 63A are bored in through hole formation positions on a base board laminated with conductor layers, which consist of a conductive material, on one surface thereof and the other surface thereof and at the same time, a first process for patterning the conductor layers 55 and 56, which are respectively laminated on the one surface of the base board and the other surface of the base board, a second process for laminating resist layers 57 and 60, which consist of a photoresist, on the layers 55 and 56, which are respectively laminated on the one surface of the base board and the other surface of the base board, and a third process, wherein the layers 57 and 60 are exposed and developed into a prescribed pattern, whereby via holes 57A and 60A are respectively formed in the layers 57 and 60 so as to communicate with the holes 52A, 52B and 63A bored in the base board, are provided. Hereby, drilling work processes can be executed together at one time and at the same time, the diameter of lands on the through holes in the outermost conductor layers 55 and 56 can be lessened. In this way, a multilayer interconnection board can be made to correspond fully to a high-density mounting.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. TECHNICAL FIELD OF THE INVENTION Conventional Technology (FIGS. 4 to 10) Problems to be Solved by the Invention (FIGS. 4 to 10) Means for Solving the Problems (FIGS. 1 to 3) Embodiments of the Invention (FIGS. 1 to 3) Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer wiring board, and is suitable for application to, for example, a photo via board and a method for manufacturing the same.

[0003]

2. Description of the Related Art Conventionally, a multilayer wiring board (a four-layer wiring board in the following example) is manufactured by the following procedure shown in FIGS. 4 (A) to 5 (C). That is, first, as shown in FIG. 4A, a copper foil 2 is formed on each of the one surface and the other surface of the insulating substrate 1.
As shown in FIG. 4B, a through hole 3A is formed at a predetermined position of the double-sided copper clad laminate 3 to which A and 2B are attached.
To form

Next, a plating layer 4A is formed on the inner surface of the through hole 3A as shown in FIG. 4C by a copper plating process from one side and the other side of the double-sided copper-clad laminate 3. Thus, the through hole 4AX is formed, thus electrically connecting the copper foils 2A and 2B on one side and the other side of the double-sided copper-clad laminate 3 to each other. At this time, copper plating layers 4B and 4C are also formed on the copper foils 2A and 2B on the one surface side and the other surface side of the double-sided copper-clad laminate 3, respectively.

Then, as shown in FIG. 4 (D), the double-sided copper-clad laminate 3 has a second conductor layer 5 consisting of the copper foil 2A and the copper plating layer 4B on one side of the double-sided copper-clad laminate 3, and the double-sided copper-clad laminate. The second and third wiring patterns are formed by respectively patterning the copper foil 2B on the other surface side of the third wiring layer 3 and the third conductor layer 6 formed of the copper plating layer 4C, and thereafter, as shown in FIG. As shown in E), the single-sided copper-clad laminates 8 and 9 are attached to one side and the other side of the double-sided copper-clad laminate 3 with the prepregs 7A and 7B serving as an adhesive layer sandwiched between them. The layer substrate 10 is formed.

Next, as shown in FIG. 5 (A), a through hole 10A penetrating the four-layer substrate 10 is formed by using a cone at a predetermined position of the four-layer substrate 10, and then one surface side of the four-layer substrate 10 and As shown in FIG. 5 (B), the through-hole hole 11AX is formed by forming the plating layer 11A on the inner surface of the through-hole 10A by the texture treatment from the other surface side, and thus the four-layer substrate 10 is formed. The copper foils 12 and 13 on the one surface and the other surface are electrically connected to each other. At this time, each of these copper foils 12,
Copper plating layers 11B and 11C are also laminated on 13 respectively.

Subsequently, as shown in FIG. 5C, the first conductor layer 14 composed of the copper foil 12 and the copper plating layer 11B on one side of the four-layer board 10 and the other four-layer board 10 are formed. Each of the first and fourth conductor layers is formed by patterning the copper foil 13 on the surface side and the fourth conductor layer 15 including the copper plating layer 11C by etching using a photographic method. Wiring patterns are formed on 14 and 15, respectively. This makes it possible to obtain a four-layer wiring board 16 in which desired wiring patterns are formed on the first to fourth conductor layers 14, 5, 6, and 15, respectively.

A tenting method, which is one of the wiring pattern forming methods, is shown in FIGS. In this method, first, as shown in FIG. 6 (A), a double-sided copper-clad laminate in which copper foils 21A and 21B are attached to one surface and the other surface of the insulating substrate 20 is cut into a predetermined shape, and thus obtained. A through hole 22A is formed at a predetermined position of the double-sided copper-clad laminate 22 by using a cone as shown in FIG. 6 (B).

Next, the electroless plating treatment from one side and the other side of the double-sided copper-clad laminate 22 is performed as shown in FIG.
As described above, the plating layer 23A is formed on the inner surface of the through hole 22A, thus electrically connecting the copper foils 21A and 21B on one surface side and the other surface side of the double-sided copper-clad laminate 22 to each other. At this time, the first copper plating layers 23B and 23C are laminated on the copper foils 21A and 21B, respectively.

Next, electrolytic plating is applied to the double-sided copper-clad laminate 22 this time, so that the first copper-plating on one side and the other side of the double-sided copper-clad laminate 22 as shown in FIG. 6D. Layer 2
2B on 3B and 23C and on the plating layer 23A, respectively.
The copper plating layers 24B and 24C or the plating layer 24A are laminated and formed, and thereafter, as shown in FIG. 1 of photoresist so as to cover the copper plating layers 24B and 24C.
The seed dry film 25A, 25B is pressure bonded.

Subsequently, as shown in FIG. 7A, each of the dry films 25A and 25B is exposed in accordance with a desired wiring pattern and developed to pattern each of the dry films 25A and 25B. Figure 7
As shown in (B), the remaining dry film 25A,
Using 25B as a mask, the copper foil 21A on one side of the double-sided copper-clad laminate 22, the first conductor layer 26 including the first copper-plated layer 23B and the second copper-plated layer 24B, and the double-sided copper-clad laminate Two
The copper foil 21B on the other side of the second surface, the second conductor layer 27 composed of the first copper-plated layer 23C and the second copper-plated layer 24C are patterned by etching.

Further, as shown in FIG. 7C, after the dry films 25A and 25B are peeled off from one side and the other side of the double-sided copper-clad laminate 22, respectively, as shown in FIG.
As shown in (D), solder resists 28A and 28B are formed on one side and the other side of the double-sided copper-clad laminate 22, respectively.
Is applied, surface treatment is performed, and outer shape processing is performed. As a result, desired wiring patterns can be formed on one surface side and the other surface side of the double-sided copper-clad laminate 22, respectively.

By the way, a method of manufacturing a multilayer wiring board by stacking described above with reference to FIGS.
This is called a lamination method), but in this method, in addition to the thickness (18 [μm]) of the copper foils 2A, 2B, 12 and 13 of the copper clad laminates 3, 8 and 9, through through holes are used. 11AX
About 20 [μm] of copper material due to plating treatment to form
, The conductor layers 14 of the first to fourth layers,
The copper thicknesses of 5, 6, and 15 are close to 40 [μm].

However, in general, the copper clad laminates 3, 8, 9
In the process of patterning by etching, the thicker the copper is, the longer the etching time is required, and the etching liquid is soaked from the lateral direction, and the pattern is etched more than necessary (over-etching). Therefore, there is a problem that the wiring pattern of each conductor layer 14, 5, 6, 15 becomes thinner than a desired thickness.
Therefore, it has been difficult to form a fine pattern by the above-described lamination method.

Further, in the laminating method as described above, all the through holes 4AX, 11 including the through through hole 11AX.
Since the AX is formed entirely by using the cone, the hole diameters of the through holes 4AX and 11AX depend on the diameter of the cone. However, at present, since it is necessary to use a cone having a diameter of 0.3 [mm] even if it has a small diameter due to the problem of the strength of the cone, the uppermost and lowermost conductor layers (one layer in a four-layer wiring board) of the formed multilayer wiring board 16 are used. There is a problem that the land diameter of the through-holes 11AX in the first and fourth conductor layers 14 and 15) becomes large, resulting in a decrease in wiring efficiency.

Further, in the laminating method as described above, after the single-sided copper-clad laminates 8 and 9 are attached to both sides of the double-sided copper-clad laminate 22, the perforating work for forming the through through holes 11AX is performed. Therefore, in addition to the alignment accuracy between the double-sided copper-clad laminate 22 and each of the single-sided copper-clad laminates 8 and 9, the cone alignment accuracy with respect to the four-layer board 10 in the drilling process is also necessary. Since the land diameter of the through-hole 11AX is determined according to the positioning accuracy, the land diameter of the outermost conductor layer has a radius of 0.6 [mm].
However, there is a problem that the wiring efficiency further deteriorates due to the increase in the size.

On the other hand, conventionally, there is a substrate called a photo via substrate that can be used for high-density mounting (hereinafter, a 4-layer photo via substrate will be described as a photo via substrate). Usually, in this type of substrate, for example, FIG.
It is manufactured by the following procedure shown in (A) to FIG. 10 (C).

That is, first, as shown in FIG. 8A, the double-sided copper-clad laminate 32 in which copper foils 32A and 32B are adhered to one surface and the other surface of the insulating substrate 30, respectively, is placed at a predetermined position in FIG. After forming the through hole 32A with a cone like this,
As shown in FIG. 8C, the through holes 32 are formed by the copper plating treatment from one side and the other side of the double-sided copper-clad laminate 32.
The through hole 33AX is formed by forming the plating layer 33A on the inner surface of A, and thus each copper foil 31A, 31
Electrically connect between B. At this time, each of these copper foils 3
Copper plating layers 33B and 33C on 1A and 31B, respectively
Is formed.

Then, as shown in FIG. 8D, the copper foil 31A and the copper plating layer 3 on one surface of the double-sided copper-clad laminate 32 are formed.
3B second conductor layer 34 and double-sided copper clad laminate 32
The second-layer and third-layer wiring patterns are formed by respectively patterning the copper foil 31B on the other surface side and the third-layer conductor layer 35 formed of the copper plating layer 33C.

Next, as shown in FIG. 8 (E), a resist layer 36 is formed by applying photo resistitos to one surface of the double-sided copper-clad laminate 32, and thereafter, as shown in FIG.
As shown in FIG. 9A, the resist layer 36 is exposed from the same surface side of the double-sided copper clad laminate 32 through the mask 35 and developed to develop the resist layer 36 as shown in FIG. 9B.
A via hole 36A for establishing electrical connection between the first conductor layer and the second conductor layer 34 is formed at a predetermined position.

Subsequently, a photoresist is applied to the other surface of the double-sided copper-clad laminate 32 to form a resist layer 38. Thereafter, as shown in FIG. 9C, the resist layer 38 is formed on both sides. By exposing and developing from the same surface side of the copper clad laminate 32 through the mask 39, as shown in FIG.
As shown in (D), a via hole 38A for establishing electrical connection between the third conductor layer 35 and the fourth conductor layer is formed at a predetermined position of the resist layer 38.

Further, as shown in FIG. 10A, a through hole 32B for a through through hole is formed at a predetermined position of the double-sided copper-clad laminate 32 by using a cone, and then, as shown in FIG. As shown, the resist layers 36 and 38 are subjected to the copper plating treatment from one side and the other side of the double-sided copper-clad laminate 32.
The first or fourth conductor layers 40 and 41 are respectively formed on the upper side, and the plating layer 42 is formed on the inner surface of the through hole 32B.
To form the through-hole 42A, and thus the first and fourth conductor layers 40 and 41 are electrically connected.

Further after this, as shown in FIG.
The conductor layers 40 and 41 of the first and fourth layers of the four-layer substrate 43 thus formed are patterned into desired patterns. As a result, the first to fourth conductor layers 40,
It is possible to obtain a four-layer photovia substrate 44 in which 34, 35, and 41 are patterned into desired patterns.

The photo-via substrate 44 thus formed is usually provided between adjacent conductor layers (between the first and second conductor layers 40 and 34, the third and fourth conductor layers 3).
Photovoltaic 3 for electrical connection (between 5 and 41)
Since 6A and 38A are formed by the photographic method as described above, the diameter is considerably small, about 0.2 [mm], and the uppermost and lowermost conductor layers (each conductor of the first and fourth layers). Layer 4
Since the copper thickness of 0, 41) is about 20 [μm] for one plating treatment, it can be said that it is suitable for forming a fine pattern.

[0025]

However, in the photo-via substrate 44 of this type, since the through hole 32B, which is the source of the through hole 42A, is formed by the drilling process as described above, the structure shown in FIG. It is difficult to reduce the land diameter of the through-through hole 42A as in the method of manufacturing a multilayer wiring substrate by stacking described above in FIG. 5C, and as a result, wiring cannot be performed around the land of the through-hole hole 42A, resulting in wiring efficiency. There was a problem of decrease.

Further, in this drilling process, the uppermost conductor layer and the inner conductor layers (first conductor layer 4 and second conductor layer 4) are formed.
0, 34), and between the bottom and inner conductor layers (third and fourth conductor layers 35, 41), alignment accuracy is required. There was a problem that it was difficult to perform high-precision positioning because the double-sided copper-clad laminate 32 with a work size of 600 [mm] was moved while the workpiece was fixed to make holes.

Further, in this type of photo-via substrate 44, since this positioning accuracy is included in addition to the diameter of the cone (drill), the uppermost and lowermost conductor layers (first conductor layer and fourth conductor layer). Through-hole 4 in 40, 41)
The land diameter of 2A is large, and the drilling process is 2
There was a problem that it took tact time because it was divided into times.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a method for manufacturing a multilayer wiring board which can sufficiently cope with high-density mounting.

[0029]

In order to solve the above problems, according to the present invention, a through hole is formed at a position where a through hole is formed in a base substrate on which a conductor layer made of a conductive material is laminated on one surface and / or the other surface. At the same time, the first step of patterning the conductor layer of the base substrate, the second step of laminating a resist layer made of photoresist on the conductor layer of the base substrate, and the resist layer is exposed to a predetermined pattern and developed. Thus, a third step of forming a via hole in the resist layer so as to communicate with the through hole of the base substrate is provided.

In this case, for example, after the conductor layer is formed on the resist layer while avoiding the via hole, the conductor layer is patterned, and then the second and subsequent steps are repeated in the same manner. It is possible to form a through-hole therethrough. In the multilayer wiring board formed in this case, since the step of forming the through hole in the base substrate to form the through through hole is performed not after the resist layer is sequentially laminated on the conductor layer, but before that.
It is not necessary to perform the drilling process multiple times, and the drilling for through-holes can be performed using a cone with a smaller diameter than the drilling for the final multilayer wiring board. The land diameter of the through hole in the outermost conductor layer can be reduced.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A to 3B show a manufacturing procedure of a multilayer wiring board (four-layer wiring board) according to an embodiment. First, an insulating substrate 50 as shown in FIG. 1 (B) at the inner layer through-hole forming position and the through-hole forming position of the double-sided copper-clad laminate 52 in which copper foils 51A and 51B are adhered to one surface and the other surface, respectively.
, The first and second through holes 52A, 5
Drill 2B respectively.

Then, as shown in FIG. 1C, the inner surfaces of the first and second through holes 52A and 52B are subjected to the plating treatment from one side and the other side of the double-sided copper-clad laminate 52. The first and second through holes 53AX and 53BX are formed by forming the plating layers 53A and 53B respectively on the copper foils 51A and 51A of the double-sided copper clad laminate 52.
Make electrical connection between B. At this time, each of these copper foils 5
Copper plated layers 54A and 54B on 1A and 51B, respectively
Is formed.

Next, the second conductor layer 55 consisting of the copper foil 51A and the copper plating layer 54A on one side of the double-sided copper-clad laminate 52, the copper foil 51B on the other side of the double-sided copper-clad laminate 52, and A desired wiring pattern is formed by patterning each of the third conductor layer 56 formed of the copper plating layer 54B as shown in FIG. 1D.

Subsequently, as shown in FIG. 1E, a resist layer 57 is formed by applying a photoresist to one surface of the double-sided copper-clad laminate 52, and thereafter, as shown in FIG.
As shown in (A), openings 58 are formed on the resist layer 57 at positions corresponding to via holes for establishing electrical connection between the first conductor layer and the second conductor layer 55.
After positioning and placing the first mask 58 having A formed therein, the resist layer 57 is exposed from the same surface side of the double-sided copper-clad laminate 52 through the first mask 58.

At this time, the second through hole 53 of the double-sided copper-clad laminate 52 is also provided on the other side of the double-sided copper-clad laminate 52.
After positioning and abutting a second mask 59 having an opening 59A corresponding to each BX, the resist layer 57 is formed through the second mask 59 and the second through hole 53BX sequentially. Exposure is performed from the different surface side of the double-sided copper clad laminate 52.

After that, the resist layer 57 is further developed to electrically connect the first conductor layer 55 and the second conductor layer 55 at predetermined positions of the resist layer 57 as shown in FIG. A first via hole 57A for forming the second through hole 53BX is formed immediately above the second through hole 53BX, and a second via hole 57B communicating with the second through hole 53BX is formed immediately above the second through hole 53BX.

Next, a photoresist layer 60 is formed by applying a photoresist to the other surface of the double-sided copper-clad laminate 52 (FIG. 2 (B)).
As shown in (C), openings 61 are formed on the resist layer 60 in correspondence with the positions of via holes for establishing conduction between the third conductor layer 56 and the fourth conductor layer.
After positioning and placing the third mask 61 having A formed therein, the resist layer 60 is exposed from the same side of the double-sided copper-clad laminate 52 through the first mask 61.

At this time, the second through hole 53 of the double-sided copper-clad laminate 52 is also provided on one side of the double-sided copper-clad laminate 52.
After positioning and abutting a fourth mask 61 having an opening 61A corresponding to each BX, the resist layer 60 is formed through the second mask 61 and the second through hole 53BX sequentially. Exposure is performed from the different surface side of the double-sided copper clad laminate 52.

After that, the resist layer 60 is further developed, so that the resist layer 6 is formed as shown in FIG.
A first via hole 60A for establishing electrical connection between the third conductor layer 56 and the fourth conductor layer is formed at a predetermined position of 0, and the second via hole 53BX is provided directly above the second through hole 53BX. A second via hole 60B communicating with the through hole 53BX is formed.

As a result, the multilayer plate 63 thus formed
Then, a through hole 63A including the second via hole 57B of the resist layer 57, the second through hole 53BX of the double-sided copper clad laminate 52, and the second via hole 60B of the resist layer 60 is formed.

Next, as shown in FIG. 3A, a first conductor layer 64 is formed on one surface side of the multilayer board 63 by copper plating treatment from one surface side and the other surface side of the multilayer board 63. At the same time, the fourth conductor layer 65 is formed on the other surface side of the multilayer board 63.
To form

At this time, a copper material is also deposited in the through holes 63A of the multi-layer plate 63 to form through through holes 66 for electrically connecting the first and fourth conductor layers 64, 65. .

After this, as shown in FIG. 3B, the conductor layers 64 and 65 of the first and fourth layers formed on the one surface side and the other surface side of the multilayer board 63 are respectively formed into desired patterns. Pattern. As a result, it is possible to obtain the multilayer wiring board 67 in which the conductor layers 64, 55, 56 and 65 having desired patterns are laminated.

In the above structure, in the method for manufacturing a multilayer wiring board, the through-hole 52B is formed at the position where the through-hole is formed in the double-sided copper clad laminate 52 (FIG. 1 (B)), and the through-hole 52B is formed. The through hole 53BX is formed by forming the plating layer 53B on the inner surface (FIG. 1C).

Next, the resist layers 57 and 60 sequentially formed on one surface side and the other surface side of the double-sided copper clad laminate 52 are sequentially exposed from the other surface side or the one surface side through the through holes 53BX. Through holes 63A are formed by forming via holes 57B and 60B at positions directly above and below the hole 53BX, respectively (FIG. 2A).
-FIG. 2 (D).

Thereafter, the first and fourth conductor layers 64 and 65 are respectively formed by plating treatment from the one surface side and the other surface side of the thus formed multilayer plate 63, and at this time, through holes are formed. By depositing a copper material in 63A as well, a through-hole 66 for electrically connecting the first and fourth conductor layers 64, 65 is formed (see FIG. 3).
(A)), and thereafter the first and fourth conductor layers 64, 6
5 is patterned into a desired pattern.

Therefore, according to this method for manufacturing a multilayer wiring board, the drilling process required to form the through-holes 66 is performed by the inner conductor layers (the second conductor layer 55 and the third conductor layer 55). , 56) for conductive connection between the through holes 5
Since the drilling process can be collectively performed at a time when 2A is drilled, compared with the laminating method described above in FIGS. 4 and 5 and the photovia method described in FIGS. 8 to 10, accordingly. Thus, the multilayer wiring board can be manufactured more easily and in a shorter time.

Further, in this method for manufacturing a multilayer wiring board, since all the drilling is performed in one step as described above, the inner conductor layers and the outer conductor layers (first conductor layer 6 and second conductor layer 6) are formed.
Between 4, 55, the third and fourth conductor layers 56, 65
Does not require drill alignment in (between).

In addition to this, in this method of manufacturing a multilayer wiring board, through-holes 52B pre-drilled in the double-sided copper clad laminate 52 are formed.
Since the through through-hole 66 is formed by using, the multi-layer plate 63 having a large thickness (FIG. 2D), for example.
The double-sided copper-clad laminate 52 is formed by using a cone having a diameter smaller than that of the cone used for drilling (for example, a diameter of about 0.2 mm).
A through hole 52B for the through through hole 66 may be formed in
And after this, for example, a thickness of 0.05
The through hole 6 for forming the plating layer 53B of about [μm]
The inner diameter of 3A can be further reduced.

Therefore, according to this method for manufacturing a multilayer wiring board, each resist layer 5 is exposed by exposure through the through hole 63A.
Diameter of photo vias 57B and 60B formed in
Since it can be suppressed to about 0.10 to 0.15 [mm], the land diameter in the outermost layer of the through through hole 66 can be reduced.

Further, in this method for manufacturing a multilayer wiring board,
The resist layers 57 and 60 sequentially formed on one surface side and the other surface side of the double-sided copper-clad laminate 52 are exposed through the through holes 53BX formed in the double-sided copper-clad laminate 52, respectively. Through holes 53 in 57 and 60
Since the via holes 57B and 60B communicating with the BX are formed, the positioning accuracy of the masks 59 and 61 can be made rougher as compared with the case where exposure is performed from the same side as the resist layers 57 and 60. There is also an advantage that the manufacturing process can be facilitated.

According to the above configuration, the double-sided copper clad laminate 52
A through hole 52B is formed at the through hole forming position of
After forming the plating layer 53B on the inner surface of the through hole 52B, the resist layers 57 and 60 sequentially formed on the one surface side and the other surface side of the double-sided copper clad laminate 52 are respectively separated through the through hole 52B. The via holes 5 are formed directly above and below the through holes 52B by sequentially exposing from the surface side or one surface side.
By forming 7B and 60B respectively, the through hole 63
A is formed, and then the first and fourth conductor layers 64 and 65 are respectively formed by plating treatment from the one surface side and the other surface side of the multilayer board 63 thus formed, and at the same time, through holes are formed. By forming the through-holes 66 by depositing the copper material in the 63A as well, the land diameter of the through-holes 66 in each outermost conductor layer can be reduced, and thus high-density mounting can be achieved. It is possible to realize a method for manufacturing a multilayer wiring board that can sufficiently cope with the above.

In the embodiment described above, the present invention is applied to a multilayer wiring board 67 having four conductor layers 64, 55, 56 and 65.
However, the present invention is not limited to this and can also be applied to the case of manufacturing a multilayer wiring board other than four layers. In practice, when a multilayer wiring board having four or more layers is formed using the present invention, until the copper material is finally deposited in the through hole for the through through hole or the through hole is formed, the through hole is not exposed. It is necessary to make the land diameter so that a photo via hole can be formed by backside exposure so that it will not be blocked by resist or copper plating, but if the light can pass through, it will eventually penetrate the through hole. The state in which the light-transmissive substance is filled may be provided until the copper material is deposited in the holes or the through-hole plating is formed.

Further, in the above-mentioned embodiment, the conductor layers 64, 55, are sequentially formed on one surface side and the other surface side of the double-sided copper clad laminate 52.
Although the case where the layers 56 and 65 are formed is described, the present invention is not limited to this, and the conductor layers may be sequentially formed on one surface of the single-sided copper-clad laminate having the copper foil attached thereto. Of course, various other base substrates can be applied as a substrate (this is referred to as a base substrate) which is a base of the formed multilayer wiring substrate.

Further, in the above-described embodiment, the resist layers 57 and 60 formed on one side and the other side of the double-sided copper-clad laminate 52 are exposed through different sides of the double-sided copper-clad laminate 52. The case where the via holes 57B and 60B communicating with the hole 53BX are formed has been described, but the present invention is not limited to this, and these resist layers 5 are not limited thereto.
The via holes 57B and 60B may be formed by exposing 7 and 60 from the same surface side of the double-sided copper clad laminate 52.

[0057]

As described above, according to the present invention, a through hole is formed at a position where a through hole is formed in a base substrate having a conductor layer made of a conductive material laminated on one surface and / or the other surface, and the base substrate is formed. Of the base substrate, a second step of laminating a resist layer made of photoresist on the conductor layer of the base substrate, and a step of exposing the resist layer to a predetermined pattern and developing the resist layer to form a base substrate. By providing the third step of forming a via hole in the resist layer so as to communicate with the through hole, the drilling step can be performed at one time and the through hole in the outermost conductor layer can be formed. It is possible to reduce the land diameter, and thus it is possible to realize a method for manufacturing a multilayer wiring board that can sufficiently cope with high-density mounting.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing procedure of a multilayer wiring board according to an embodiment.

FIG. 2 is a cross-sectional view showing the manufacturing procedure of the multilayer wiring board according to the example.

FIG. 3 is a cross-sectional view showing the manufacturing procedure of the multilayer wiring board according to the example.

FIG. 4 is a cross-sectional view showing a conventional procedure for manufacturing a multilayer wiring board by lamination.

FIG. 5 is a cross-sectional view showing a manufacturing procedure of a conventional multilayer wiring board by lamination.

FIG. 6 is a cross-sectional view showing a pattern forming procedure by a tenting method.

FIG. 7 is a cross-sectional view showing a pattern forming procedure by a tenting method.

FIG. 8 is a cross-sectional view showing a procedure for manufacturing a conventional photovia substrate.

FIG. 9 is a cross-sectional view showing a procedure for manufacturing a conventional photovia substrate.

FIG. 10 is a cross-sectional view showing a procedure for manufacturing a conventional photovia substrate.

[Explanation of symbols]

52: Double-sided copper clad laminate, 52A, 52B, 63A
Through hole, 53AX, 53BX ... through hole, 55,
56, 64, 65 ... Conductor layer, 57, 60 ... Resist layer, 57A, 60A ... Via hole, 58, 59, 6
1, 62 ... Mask, 63A ... Through hole, 66 ... Through hole, 67 ... Multilayer wiring board.

Claims (2)

[Claims] 1. A through hole is formed at a position where a through hole is formed in a base substrate having a conductor layer made of a conductive material laminated on one surface and / or the other surface, and the conductor layer of the base substrate is patterned. And a second step of laminating and forming a resist layer made of photoresist on the conductor layer of the base substrate, and exposing the resist layer to a predetermined pattern and developing the through hole of the base substrate. And a third step of forming a via hole in the resist layer so as to communicate with the above-mentioned resist layer. 2. In the third step, the exposure of the resist layer for forming the via hole communicating with the through hole of the base substrate is performed from the surface side of the base substrate different from the resist layer. The method for manufacturing a multilayer wiring board according to claim 1, wherein the method is performed through the through hole of the base substrate.