JP3005546B1 - Method of manufacturing build-up wiring board - Google Patents

Abstract

A method of manufacturing a build-up wiring board capable of forming bottomed holes simultaneously and reliably. SOLUTION: An uncured resin layer 13R whose surface 13A is exposed to light is formed on a surface 14A of a substrate 14 to be laminated, and has mask diameters MD11 and MD12 and target diameters HND11, HND.
Exposure is performed using a mask M on which light-shielding patterns MP11 and MP12 for forming via holes 11 and 12 of ND12 are formed. The resin layer surface is light-cured except for portions corresponding to the light-shielding patterns. Is removed, and the resin layer is thermally cured to form a resin insulating layer 13 having a via hole having a depth substantially equal to the depth of the surface of the substrate to be laminated.

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 build-up wiring board, and more particularly, to a method of manufacturing a build-up wiring board formed by laminating a holed insulating resin layer using photolithography technology. About.

[0002]

2. Description of the Related Art Conventionally, a build-up wiring board is sequentially formed by laminating a holed insulating resin layer on a laminated substrate having a core substrate or a resin insulating layer by using a photolithography technique. It has been known.
Specifically, a photosensitive resin layer is formed on a substrate to be laminated, and is exposed using a mask having a bottomed hole forming pattern (light-transmitting pattern or light-shielding pattern) having a predetermined diameter. The unnecessary portion (portion having a bottomed hole) is dissolved, removed, developed, and cured to form an insulating resin layer having a predetermined bottomed hole. According to this method, a bottomed hole having a small diameter can be formed with high precision. Such a bottomed hole is used, for example, as a via hole for forming a via conductor (photo via conductor) that connects wiring layers formed above and below the insulating resin layer.

[0003] By the way, at the time of development, the side portion of the bottomed hole which should not be removed may be dissolved and removed, and the bottomed hole may become large. The photo-curing is inadequate on the inner side of the surface even if it becomes light-cured and becomes insoluble due to exposure (in the case of negative type), or the part which is insoluble due to non-exposure is not completely insoluble in the developing solution. This is because the etching proceeds in the radial direction of the bottomed hole as well because it partially dissolves in the case of the positive type. In particular, when using a photosensitive resin that forms a photocurable layer on the surface due to exposure but does not cure inside, such as a photosensitive resin that is insoluble near the surface but easily dissolves inside the developer. In this case, the opening on the front side has a diameter substantially the same as the diameter of the bottomed hole forming pattern, but the etching easily proceeds not only in the axial direction but also in the radial direction of the bottomed hole inside. However, when a plurality of bottomed holes having the same depth and diameter are formed simultaneously, development (etching) proceeds in the same manner for any of the bottomed holes, so that the diameter of the completed bottomed hole may vary. There is no.

[0004]

However, when the bottomed holes having different diameters and depths are simultaneously formed in one resin insulating layer, the diameter of the actually formed bottomed hole is different from each target diameter. Was biased to be large or small, and a bottomed hole having a large error was sometimes formed. It is considered that the ease of etching in the radial direction varies depending on the diameter and depth of the bottomed hole.

For example, the two via holes 101 and 102 formed in the insulating resin layer 103 of the build-up wiring board 100 shown in FIG. 7A are both lands (via receiving holes) formed on the surface 104 A of the laminated substrate 104. Pad) 1
07,108, so the depth is the same,
The diameter of the via hole 102 is larger than that of the via hole 101. In such a case, as the mask diameter of the mask M used at the time of exposure is larger, that is, as the target diameter of the bottomed hole to be formed is larger, the etching in the radial direction is more likely to proceed, and the target diameter is actually completed. It has been found that the diameter of the bottomed hole is biased toward the larger side. Therefore, even when the via hole 101 formed by the light-shielding pattern with the mask diameter MP101 (in the case of the negative type) is formed with the via diameter D101 (= HND101) substantially equal to the target diameter HND101, the light-shielding pattern with the mask diameter MP102 is used. In the via hole 102 to be formed, the via diameter D102 is larger than the target diameter HND102 (D102> HND10).
2). The larger the diameter of the bottomed hole, the more easily the developer enters and exits the bottomed hole, and more of the developer comes into contact with the side surface of the bottomed hole. It is considered that the diameter tends to be further increased in the hole.

[0006] The resin insulating layer 103 is formed of a resin in which a photocurable layer 103K is formed on the surface 103A side when exposed, but the photocurable layer is not formed up to the inside. Are mask patterns MP101, M on the opening side (surface 103A side).
Although the mask diameters are substantially the same as the mask diameters MD101 and MD102 of P102, the resin is also etched in the radial direction inside, so that the diameter becomes larger than the mask diameter MD101 and the like.
The inside is larger in diameter (jar) than the entrance. Therefore, as described later, it is preferable to increase the diameter near the opening of the via hole 101 and the like.

In the two via holes 201 and 202 formed in the insulating resin layer 203 of the build-up wiring board 200 shown in FIG. 7B, mask diameters MD201 and MD2 of the mask patterns MP201 and MP202 to be used.
02 is the same (MD201 = MD202), but the depth of the via hole to be formed is different. That is, the via hole 20
The depth of the via hole 2 is up to the substantially flat land 107 formed on the surface 204A of the substrate 204 to be laminated.
02 has a depth up to the bottom of the substantially concave via conductor 208 formed in the resin insulating layer (surface layer of the laminated substrate 204) 205 below the resin insulating layer 203 in the figure.
It is about twice as deep as 01. In such a case, it has been found that the smaller the depth of the bottomed hole to be formed, the more the diameter of the actually formed bottomed hole is biased toward a side larger than the target diameter. Accordingly, the deep via hole 202 formed by the light-shielding pattern having the mask diameter MP202 has a via diameter D202 (= HND20) substantially equal to the target diameter HND202.
Even when the via hole 201 is formed in the light shielding pattern having the mask diameter MP201, the via hole 201 has the target diameter HN.
The via diameter D201 is larger than D201 (D201
> HND201).

[0008] The deeper the depth of the bottomed hole to be formed, the longer it takes to form the bottomed hole. Therefore, when the bottomed holes having different depths are formed at the same time, if the development is performed in accordance with the development time of the deep bottomed hole, the shallow bottomed hole is formed first. After that, since the shallow bottomed hole cannot proceed further in the depth direction, most of the developer entering and exiting the shallow bottomed hole is used for the radial etching, so the radial etching is not performed. It is considered that the diameter is likely to be large due to the shallow bottomed hole because it easily advances. On the other hand, if the development time is shortened according to the diameter of the shallow bottomed hole,
In some cases, a deep bottomed hole cannot be sufficiently developed (perforated), and a highly reliable bottomed hole cannot be formed, such as a resin residue remaining in the hole.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a small error from a target diameter regardless of the diameter and depth of the bottomed hole, and simultaneously and reliably forms the bottomed hole. It is an object of the present invention to provide a method of manufacturing a build-up wiring board that can be used.

[0010]

Means for Solving the Problems, Functions and Effects The solution is a method for manufacturing a build-up wiring board in which a resin insulating layer is laminated on the surface of a substrate to be laminated.
On the surface of the substrate to be laminated, a resin layer forming step of forming an uncured resin layer at least the surface of which is exposed by exposure, and exposed using a mask in which a plurality of bottomed hole forming patterns are formed, the resin Exposing at least the surface thereof to be insoluble in a developer except for a portion corresponding to the plurality of bottomed hole forming patterns in the layer; and A developing step of removing a portion corresponding to the formation pattern; and a curing step of curing the resin layer to form a resin insulating layer having a bottomed hole with the bottom surfaces of the plurality of stacked substrates as bottoms. In the mask, the target diameter HND of the bottomed hole becomes smaller as the depth of the bottomed hole formed at the same time becomes smaller and the diameter thereof becomes larger.
And the difference HND between the mask diameter MD of the bottomed hole forming pattern and
-A method for manufacturing a build-up wiring board, characterized in that the mask has the bottomed hole forming pattern formed so that the mask diameter reduction amount AD given by MD is increased.

According to the present invention, in the bottomed hole forming pattern formed in the mask, the smaller the depth of the simultaneously formed bottomed hole and the larger the diameter, the smaller the mask diameter reduction amount AD (= H).
ND-MD). That is, the mask diameter MD of the bottomed hole forming pattern actually formed on the mask is:
In consideration of the fact that etching proceeds not only in the depth direction but also in the radial direction in the developing step, the target diameter HND of the bottomed hole is made smaller by the mask diameter contraction amount AD than that.
Moreover, the smaller the depth of the bottomed hole to be formed and the larger the diameter, the larger the size of the mask diameter reduction amount AD. That is, the mask diameter MD of the bottomed hole forming pattern is relatively reduced.

Thus, for example, even with a bottomed hole having substantially the same target diameter HND, a bottomed hole formation pattern for a shallow bottomed hole is compared to a bottomed hole formation pattern for a deep bottomed hole. Thus, the mask diameter reduction amount AD is large, and therefore, the mask diameter MD is reduced. For this reason, in the bottomed hole having a small depth, the developer is relatively difficult to enter and exit, so that the etching speed is reduced and the etching in the radial direction is also suppressed. Therefore, even if the development is performed for a relatively long time so that a deep bottomed hole can be reliably formed, the etching amount in the radial direction is small in the shallow bottomed hole. Target diameter HN with bottom hole
A bottomed hole having a diameter close to D and having a small error can be formed.

[0013] For example, even with a bottomed hole having the same depth, a bottomed hole formation pattern for a bottomed hole having a large target diameter HND is smaller than a bottomed hole formation pattern for a bottomed hole having a small target diameter. The mask diameter reduction amount AD is large, and accordingly, the mask diameter MD of the bottomed hole forming pattern is reduced for the size of the target diameter HND. For this reason, in the bottomed hole having a large target diameter, although the developer relatively easily enters and exits and the etching in the radial direction is easy to proceed, the mask diameter MD of the bottomed hole forming pattern is considerably smaller than the target diameter HND ( Since the mask diameter reduction amount AD is increased), the target diameter HND will not be reached unless the etching amount in the radial direction increases.
Therefore, the bottomed hole having a small diameter and the bottomed hole having a large diameter can be similarly formed with a diameter close to the target diameter HND and having a small error. As described above, the bottomed hole forming pattern is formed in consideration of the mask diameter reduction amount AD based on the depth and diameter of the bottomed hole to be formed. A hole can be formed, and further, any bottomed hole can reduce the error from the target diameter HND.

In the present specification, the substrate to be laminated may be any substrate as long as a resin insulating layer can be formed on the surface thereof.
Core board made of resin or composite material such as epoxy resin composite material, ceramic board made of alumina or aluminum nitride, ceramic multilayer wiring board, laminated board with resin insulating layer already formed on the surface of core board or ceramic multilayer wiring board And the like. In addition, Cu, N
Wirings, lands (pads), via conductors, and the like made of i, Ag, Ag-Pd, W, Mo, and the like may be formed.

Further, the uncured resin layer whose surface is exposed at least by exposure is such that a portion exposed over the entire thickness of the resin layer becomes insoluble in a developer (negative type), or In addition to those that become soluble (positive type), the surface of the resin layer among the exposed portions becomes insoluble (negative type) or soluble (positive type) in the developer, and the interior is soluble in the developer. Is also included. For example,
Prob as a resin that forms a photocured layer on the surface by exposure
Examples include imer52 (a photosensitive epoxy resin manufactured by Ciba-Geigy) and Provicoat 5000 (an epoxy resin manufactured by Nippon Paint Co., Ltd.). Further, even if a resin layer having a two-layer structure in which an uncured photosensitive resin layer is disposed on an uncured non-photosensitive resin layer is used, the resin can have photosensitivity near the surface.

As the mask, a known mask may be used. For example, a mask using an organic film such as glass or a PET film as a base material and using chromium or the like as a light-shielding film may be used. Further, the bottomed hole forming pattern formed in the mask is formed according to the photosensitivity (negative type / positive type) of the resin layer. Specifically, when the photosensitivity of the resin layer is negative type,
The light-shielding pattern, that is, the light-shielding film itself is used. In the case of a positive type, the light-transmitting pattern, that is, the through-hole of the light-shielding film is used. Therefore,
The mask diameter of the bottomed hole forming pattern corresponds to the outer diameter of the diameter light shielding film itself or the inside of the through hole of the light shielding film. The formed bottomed hole can be used for a desired application.For example, plating or the like is applied to form a via hole for forming a via conductor, or an external terminal such as a pin is soldered or connected. It can be used as a bottomed hole for forming a terminal conductor to be brought into contact.

Another solution is a method for manufacturing a build-up wiring board in which a resin insulating layer is laminated on a surface of a substrate to be laminated, wherein at least the surface of the substrate to be laminated is exposed to light. A resin layer forming step of forming an uncured resin layer that is exposed to light, and a first bottomed hole forming pattern for forming a first bottomed hole having a target diameter HND1.
A first bottomed hole forming pattern having a mask diameter MD1, and a second having a target diameter HND2 larger than the target diameter HND1.
A second bottomed hole forming pattern for forming a bottomed hole, wherein the second mask diameter M is larger than the first mask diameter MD1.
Exposure is performed using a mask having a second bottomed hole forming pattern having D2 formed thereon, except for a portion of the resin layer corresponding to the first bottomed hole forming pattern and the second bottomed hole forming pattern. An exposure step of insolubilizing at least the surface of the resin layer with a developing solution, and a developing process of removing portions of the resin layer corresponding to the first bottomed hole forming pattern and the second bottomed hole forming pattern with the developing solution. A step of curing the resin layer to form a resin insulating layer having the first bottomed hole and the second bottomed hole having substantially the same depth with the bottom surface of the substrate to be laminated as a bottom, The first bottomed hole forming pattern, wherein the second mask diameter reduction amount AD2 given by AD2 = HND2-MD2 is larger than the first mask diameter reduction amount AD1 given by AD1 = HND1-MD1. Passing A method for manufacturing a build-up wiring board, characterized in that the mask second bottomed hole formed pattern is formed.

According to the present invention, when the target diameter HND2 of the second bottomed hole is larger than the target diameter HND1 of the first bottomed hole to be formed (HND1 <HND2), the first and second holes formed on the mask are formed. First mask diameter MD1 of bottomed hole forming pattern
The second mask diameter MD2 is larger (MD1 <MD2). In addition, the first mask reduction amount AD1 (= HND
1−MD1), the second mask reduction amount AD2 (= H
ND2-MD2) (AD1 <AD2). That is, the mask diameters MD1 and MD2 of the first and second bottomed hole forming patterns actually formed on the mask are such that the etching proceeds not only in the depth direction but also in the radial direction in the developing step. Considering that the larger the diameter is, the easier the etching in the radial direction proceeds, the larger the target diameter of the bottomed hole is, the larger the mask diameter contraction amount is adjusted.

Thus, even with the bottomed holes having substantially the same depth (first and second bottomed holes), the bottomed hole formation pattern for the second bottomed hole having the large target diameter HND2 is the same as the first hole having the small target diameter HND1. The mask diameter reduction amount AD2 is increased (AD1 <AD) as compared with the bottomed hole forming pattern for one bottomed hole.
2) Therefore, the mask diameter MD2 of the bottomed hole forming pattern is not so large for the size of the target diameter HND2. For this reason, in the second bottomed hole having a large target diameter HND2, although the developing solution relatively easily enters and exits and the etching in the radial direction is easy to proceed, the mask diameter MD2 is smaller than the target diameter HND.
2 (the mask diameter reduction amount AD2 is large), so that the target diameter HND does not reach unless the etching amount in the radial direction increases. Therefore, both the first bottomed hole having a small diameter and the second bottomed hole having a large diameter are close to the target diameters HND1 and HND2, and can be formed as bottomed holes having a small error. As described above, since the bottomed hole forming pattern is formed in consideration of the mask diameter reduction amount based on the diameter of the bottomed hole to be formed, the error of each bottomed hole from the target diameter can be reduced.

Still another solution is a method of manufacturing a build-up wiring board in which a resin insulating layer is laminated on a surface of a substrate to be laminated, wherein at least the surface of the substrate to be laminated is exposed to light. A resin layer forming step of forming an uncured resin layer that is exposed to light, and a third bottomed hole forming pattern for forming a third bottomed hole having a target diameter of HND3;
A third bottomed hole forming pattern having a mask diameter MD3, and a fourth bottomed hole forming pattern for forming a fourth bottomed hole having a target diameter HND4 substantially equal to the target diameter HND3, wherein the third mask Fourth mask diameter M smaller than diameter MD3
Exposure is performed using a mask on which a fourth bottomed hole forming pattern having D4 is formed, and a portion of the resin layer corresponding to the third bottomed hole forming pattern and the fourth bottomed hole forming pattern. Excluding the step of exposing at least the surface thereof to be insoluble in the developing solution, and the developing solution corresponding to the third bottomed hole forming pattern and the fourth bottomed hole forming pattern of the resin layer. A developing step for removing a portion to be formed;
Curing the resin layer to form a resin insulating layer having a third bottomed hole whose bottom is the surface of the laminated substrate and the fourth bottomed hole having a depth smaller than the third hole. A method of manufacturing a build-up wiring board characterized by the following.

According to the present invention, the target diameter HND3 of the third bottomed hole to be formed is substantially equal to the target diameter HND4 of the fourth bottomed hole (HND3 ≒ HND2), but the fourth diameter shallower than the third bottomed hole.
Since the bottomed hole is formed, the fourth mask diameter MD4 is smaller than the third mask diameter MD3 (MD3> MD4) in the third and fourth bottomed hole forming patterns formed on the mask.
That is, the diameters MD3 and MD4 of the third and fourth bottomed hole forming patterns actually formed on the mask are determined so that the etching proceeds not only in the depth direction but also in the radial direction in the developing step. When the depths of the bottomed holes are different, the aimed diameters of the bottomed holes are substantially equal (HND3 ≒ HN), taking into consideration that the smaller the depth of the bottomed hole, the easier the etching proceeds in the radial direction.
Despite D2), the mask is adjusted to be smaller (MD3> MD4) as the depth of the bottomed hole to be formed is smaller.

Thus, in the fourth bottomed hole having a small depth,
Since it is relatively difficult for the developer to enter and exit, the etching speed is reduced, and the etching in the radial direction is also suppressed.
Therefore, even if development is performed for a relatively long time so that the third bottomed hole having a large depth can be reliably formed, the amount of etching in the radial direction at the fourth bottomed hole having a small depth is small. Both the third bottomed hole and the fourth bottomed hole can be close to the target diameter and have a small error. In this manner, since the bottomed hole forming pattern is formed in consideration of the mask diameter based on the depth of the bottomed hole to be formed, the bottomed hole having a large depth can be reliably formed without resin residue due to insufficient development time or the like. In addition, the error of the diameter of any of the bottomed holes from the target diameter can be reduced.

The build-up according to any of the above.
A method for manufacturing a wiring board, wherein in the developing step,
Builds that are developed multiple times, with each build being developed
To change or reverse the orientation of the wiring board
A good manufacturing method for the build-up wiring board
No.

In this way, in the developing step, the tree
How to touch the developer shower on each part of the surface of the grease layer
Of the via hole to be formed
Variations in diameter and development speed can be suppressed.

[0025]

(Embodiment 1) A method of manufacturing a build-up wiring board according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 and FIG. 2 are explanatory views showing steps of forming the via holes 11 and 12. In the resin layer forming step shown in FIG. 1A, first, a substrate to be laminated 14 having lands 17 and 18 on the surface 14A and made of a glass-epoxy resin composite material is prepared, and uncured (semi-cured) is formed on the surface 14A. The (state) resin layer 13R is formed. Specifically, a dry film (uncured film-like resin) made of Provicoat 5000 having a thickness of 50 μm is stuck on the surface 14A,
Perform prebaking for 15 minutes. This pre-baking can eliminate the stickiness of the surface of the resin layer 13R, and can prevent the glass mask M from sticking to the resin layer 13R in an exposure step described later. As described below, this resin is a negative photosensitive resin having low photosensitivity. When exposed, the surface thereof is photocured to a thickness of about 5 μm and becomes insoluble in a developing solution, but is sufficiently photocured in the interior. And a resin that dissolves in a developer.

Next, in the exposure step shown in FIG. 1B, the mask diameters MD11 and MD12 are formed on the lower surface MB, respectively.
The resin layer 13R is exposed using a glass mask M on which light-shielding patterns MP11 and MP12 made of chromium (MD11 <MD12) are formed, and the photocured layer 1 is exposed near the surface 13A.
Form 3K. The light shielding patterns MP11, MP1
Needless to say, the photocurable layer 13K is not formed on the surface 13A corresponding to No. 2. Here, the light shielding pattern M
The mask diameter MD12 of P12 is set to be relatively smaller than the target diameter HND12 of the via hole 12 to be formed in consideration of the ease of etching in the radial direction in the later-described development process. That is, the mask diameter reduction amount AD11 (= HND11-MD11) given by the difference between the target diameter HND11 of the via hole 11 and the mask diameter MD11.
Target diameter HND12 of via hole 12 and mask diameter MD
12, the mask diameter reduction amount AD12 (= H
ND12-MD12), AD11 <AD
It is set to 12.

Thereafter, the resin layer 1 is formed so as to withstand development.
3R is further subjected to a heat treatment at 80 ° C. × 45 minutes. Next, in the developing step, a developer (not shown) made of Provicoat 5000 developer is showered from the surface 13A side, and as shown in FIG. 1 (c), via holes 11 of diameters (maximum diameters) D11 and D12 are formed. 12 are formed. The via holes 11 and 12 are formed such that the lands 17 and 18 are exposed at the bottoms thereof. In this development step, the resin is dissolved from portions corresponding to the light-shielding patterns MP11 and MP12 where the photocurable layer 13K is not formed, and holes are formed in the thickness direction (downward in the figure). However, the photocurable layer 13K of the resin layer 13R is insoluble in the developing solution, but is not cured, so that it is dissolved in the developing solution. On the other hand, the inside becomes a large pot-shaped via hole with a large diameter. Here, the small diameter via hole 11
Thus, the via hole diameter D11 was formed as intended with respect to the aimed diameter HND11. Further, even in the via hole 12 having a large diameter, the etching in the radial direction is apt to progress. Therefore, by setting the mask diameter MD12 slightly smaller in advance as described above, the actual via hole diameter D12 is as expected with respect to the target diameter HND12. Value.

In the developing step, the shower pressure is preferably increased in order to make the etching amount in the radial direction as small as possible with respect to the etching amount in the thickness direction (axial direction). It is good to be cm2.
Also, when developed in the shower in this way, the via hole 1
It is also preferable in that the resin can be reliably removed from the bottom surfaces of the first and second (exposed surfaces of the lands 17 and 18). Further, in the development process, the development is performed in a plurality of times, and in each time, when the direction of the wiring board to be developed is changed or reversed, the developing solution shower which hits each part of the surface 13A of the resin layer 13R may be lost. Variations can be eliminated, and variations in the diameter of the via holes to be formed and variations in the developing speed can be suppressed.

Thereafter, in the curing step, 150 ° C. ×
Heating is performed for 120 minutes to sufficiently cure the resin layer 13R, thereby forming the insulating resin layer 13 having the via holes 11 and 12. Furthermore, in order to reliably form via conductors VC1 and VC2, which will be described later, also in the vicinity of the opening, the shape of the substantially pot-shaped via holes 11 and 12 whose inside is larger in diameter than the opening is set so that the opening has the largest diameter. Into a generally bowl-shaped shape. In particular,
Pure water is sprayed with a high-pressure shower, and the overhanging opening is cut off by impact to shape it.
Specifically, the shower pressure is set to 30 to 50 kg / cm2. As a result, as shown in FIG.
12, the resin insulating layer 13 having the substantially bowl-shaped via holes 11 and 12 was completed.

As shown in FIG. 3, via conductors VC1 and VC2 are formed in the via holes 11 and 12 and the periphery of the opening thereof by a known method, and the build-up wiring board 1 is formed.
Complete 0. For example, although not shown in detail, specifically, an electroless copper plating layer is formed in the via holes 11 and 12 and on the surface 13A of the insulating resin layer 13 by electroless plating, and a plating resist is applied thereon. Exposure and development are performed to open the via holes 11 and 12 and their peripheral edges. Further, an electrolytic copper plating layer is formed in the opening by electrolytic copper plating using the electroless copper plating layer as a common electrode, the plating resist is removed, and the exposed electroless plating layer is removed by etching to form via conductors VC1 and VC2. To form

As described above, in this embodiment, the larger the diameter of the via hole to be formed, the larger the mask diameter reduction amount AD and the smaller the mask diameter MD. Specifically, the mask diameters MD11 and M of the light-shielding patterns MP11 and MP12 are
When compared with D12, MD11 <MD12,
AD11 <AD12, and the mask diameter MD12 is set to a relatively small diameter for the size of the target diameter HND12.
For this reason, in the development process, utilizing the fact that etching proceeds more easily in the radial direction as the via diameter becomes larger, ultimately, a via hole having a smaller diameter and a via hole having a larger diameter are obtained.
Similarly, a via hole having a diameter close to the target diameter can be formed.

(Embodiment 2) Next, a method of manufacturing a build-up wiring board according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 and FIG. 5 are explanatory views showing steps of forming the via holes 21 and 22. First, the laminated substrate 24 having the lands 17 and the concave via conductors 28 on the surface 24A is prepared. The laminated substrate 24 is formed of the resin insulating layer 2
6, and has a resin insulating layer 25 made of an epoxy resin, forming a surface layer. Further, the via conductor 28 penetrates through the insulating resin layer 25 and is connected to a land 29 located below in the figure. In the resin layer forming step, FIG.
First, as shown in FIG.
Uncured (semi-cured) resin layer 2 having a thickness of 50 μm on A
Form 3R. Specifically, as in the first embodiment, a dry film made of Provicoat 5000 is attached on the surface 14A, and prebaked at 80 ° C. for 15 minutes.

Next, in the exposure step shown in FIG. 4B, the mask diameters MD21 and MD22 are respectively formed on the lower surface MB.
The resin layer 23R is exposed using a glass mask M on which light-shielding patterns MP21 and MP22 made of chromium are formed to form a photo-cured layer 23K near the surface 23A. The surface 2 corresponding to the light-shielding patterns MP21 and MP22
It goes without saying that the photocurable layer 23K is not formed on 3A. Here, in consideration of the fact that the progress of etching in the radial direction in the later-described development process differs depending on the difference in the depth of the via hole to be formed, the light shielding pattern MP
The mask diameter MD21 of 21 is relatively smaller than the target diameter HND21 of the shallow via hole 21. That is, the target diameter HND2 of the via holes 21 and 22
1, HND22 is equal, but the target diameter HND2
The mask diameter reduction amount AD21 (= HND21-MD21) given by the difference between 1 and the mask diameter MD21, and the target diameter HN
Comparing the mask diameter reduction amount AD22 (= HND22-MD22) given by the difference between D22 and the mask diameter MD22, AD21> AD22.

Further, after a heat treatment at 80 ° C. for 45 minutes, a developing solution (not shown) made of PROVICOAT 5000 developing solution is showered from the surface 23A side in the developing step, as shown in FIG. Thus, via holes 21 and 22 having diameters (maximum diameters) D21 and D22 are formed. As can be easily understood from FIG.
Is about twice the depth of the via hole 21. Therefore, in the developing step of the present embodiment, the development is performed not only while the land 27 is exposed at the bottom of the via hole 21 but also during the time until the via conductor 28 is sufficiently exposed at the bottom of the via hole 22.

In this developing step, the resin is dissolved from portions corresponding to the light shielding patterns MP21 and MP22 where the photocurable layer 23K is not formed, and holes are formed in the thickness direction. However, the photocurable layer 23K of the resin layer 23R is insoluble in the developing solution, but the inside thereof is dissolved in the developing solution. It becomes a large diameter via hole. In particular, in the via hole 21 having a shallow bottom, the development is performed for a long time in accordance with the development time of the via hole 22, so that when the land 27 is exposed, the etching does not proceed further in the depth (thickness) direction, resulting in over-etching conditions. Thus, the etching in the radial direction proceeds. However, in the present embodiment, since the mask diameter MD21 was previously made smaller, the actual via hole diameter D21 could be set to the same value as the target diameter HND21. Also, the deep via hole 22
However, the via hole diameter D22 could be formed to match the target diameter HND22, and the development time could be sufficiently long, so that the via conductor 28 could be sufficiently exposed. In the developing step, the shower pressure is preferably increased in order to make the etching amount in the radial direction as small as possible with respect to the etching amount in the thickness direction (axial direction). Is preferably 5 to 10 kg / cm 2. Also, when developed in the shower like this,
Bottom of via holes 21 and 22 (land 27, via conductor 2
8 is also preferable in that the resin can be reliably removed from the (exposed surface 8) and resin residue can be prevented.

Thereafter, in a curing step, 150 ° C. × 120
The resin layer 23 </ b> R is sufficiently cured by heating for a minute to form the insulating resin layer 23 having the via holes 21 and 22.
In order to reliably form via conductors VC3 and VC4, which will be described later, also in the openings, via holes 21 and 22 are provided.
The shape of pure water is 30 to 50 kg /
A high pressure shower of cm 2 is sprayed, and the overhanging opening is cut off by impact to shape it. Thereby, as shown in FIG. 5B, the diameters D21 and D22 are almost equal to each other (D2
1 ≒ D22), a resin insulating layer 23 having substantially bowl-shaped via holes 21 and 22 was obtained. Further, similarly to the first embodiment, via conductors VC3 and VC4 are formed on the via holes 21 and 22 and the peripheral edge of the opening, and the build-up wiring board 2 is formed.
Complete 0.

As described above, in the present embodiment, the smaller the depth of the via hole to be formed, the larger the mask diameter reduction amount AD, and the smaller the mask diameter MD. More specifically, the via holes 21 and the target diameter HND21 = HND22 are set.
2, when the mask diameters MD21 and MD22 of the light-shielding patterns MP21 and MP22 were compared, the mask diameter of the shallow via hole 21 was smaller (MD21 <MD22), that is, AD21> AD22 as compared with the mask reduction amount. Therefore, in the developing process, the shallow via hole 21
In this case, the diameter of the opening becomes small, so that the developer is relatively difficult to enter and exit, and the developing speed is reduced. In addition, since etching is suppressed in the radial direction, development is performed for a relatively long time in accordance with the deep via hole 22 so that the shallow via hole 22 has a via hole diameter D2 close to the target diameter HND22.
Can be 1.

In the above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. Nor. For example, in the above two embodiments, an example was shown in which a via hole was formed as a bottomed hole, and then a via conductor was formed. However, a terminal conductor that receives an external terminal such as a pin and is connected by soldering or abutment is used. It may be a bottomed hole or the like for forming. Also,
In the first embodiment, via holes 11 and 12 having the same depth and different diameters are formed. In the second embodiment, via holes 21 and 22 having the same depth and different diameters are formed. The same applies to the case where they are mixed. That is, the shallower the depth and the larger the diameter, the larger the mask reduction amount AD, that is, the smaller the mask diameter MD, so that a bottomed hole having the target diameter HND can be formed.

In the above embodiment, an example is shown in which a negative photosensitive resin whose surface is light-cured by exposure is used, but a positive photosensitive resin may be used in reverse. Furthermore, the surface (for example, 4 to 5 μm thick) is exposed to light.
Although the resin which becomes insoluble by curing only m) is used, the present invention may be applied to a case where a resin which becomes insoluble to the inside by exposure is used. This is because the inside is not sufficiently cured as compared to the surface, and etching may easily proceed in the radial direction when forming a bottomed hole by development. Further, the present invention may be applied to a case where an uncured resin layer having a two-layer structure in which a photosensitive resin layer is formed on a non-photosensitive resin layer is used. Further, in the above two embodiments, in each of the embodiments, a dry film is attached to form the resin layers 13R and 23R, but may be formed by applying a resin paste. Furthermore, in the above embodiment, once the resin layer 1
3R and 23R are cured to form insulating resin layers 13 and 23,
Thereafter, the overhang-shaped openings such as the via holes 11 were removed by a high-pressure shower of pure water. However, in the developing step, the developing solution was sprayed with a high-pressure shower to perform development, and the openings of the holes became overhang-shaped. May be suppressed.

[Brief description of the drawings]

FIGS. 1A and 1B show a via hole forming process according to a first embodiment, wherein FIG. 1A shows a resin forming process, FIG.
FIG. 4 is an explanatory view showing a developing step.

FIG. 2 is an explanatory diagram illustrating a completed state of the via hole according to the first embodiment;

FIG. 3 is an explanatory diagram showing a state in which a via conductor is further formed in the via hole shown in FIG. 2;

FIGS. 4A and 4B are explanatory views showing a resin forming step and an exposing step in a via hole forming step according to the second embodiment.

FIGS. 5A and 5B are explanatory diagrams showing a developing step and a completed state of a via hole forming step according to the second embodiment. FIGS.

FIG. 6 is an explanatory view showing a state in which a via conductor is further formed in the via hole shown in FIG. 5 (b).

FIGS. 7A and 7B are explanatory diagrams showing a relationship between an insulating resin layer in which a via hole is formed and a light shielding pattern of a mask, wherein FIG. 7A shows a relationship in a via hole having a different diameter, and FIG. 7B shows a relationship in a via hole having a different depth. FIG.

[Explanation of symbols]

10, 20 Build-up wiring board 11, 12, 21, 22 Via hole (bottomed hole) 13, 23 Insulating resin layer 13R, 23R Resin layer 13K, 23K Photo-cured layer 14, 24 Multi-layer substrate 14A, 24A (Multi-layer substrate Surface 25 Insulating resin layer 17, 18, 27, 29 Land (via receiving pad) 28 Via conductor M mask MP11, MP12, MP21, MP22 Light shielding pattern (bottomed hole-shaped pattern) MD11, MD12, MD21, MD22 Mask Diameter D11, D12, D21, D22 Via hole diameter HND11, HND12, HND21, HND22 Target diameter VC1, VC2, VC3, VC4 Via conductor

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoki Kito 14-18, Takatsuji-cho, Mizuho-ku, Nagoya Japan Inside Special Ceramic Industry Co., Ltd. (72) Inventor Satoshi Hirano 14-18 Takatsuji-cho, Mizuho-ku, Nagoya Japan (56) References JP-A-6-252560 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 3/46 G03F 1/08

Claims (4)

(57) [Claims] 1. A method for manufacturing a build-up wiring board, comprising laminating a resin insulating layer on a surface of a substrate to be laminated, wherein the uncured substrate is exposed to light on at least the surface of the substrate to be laminated. A resin layer forming step of forming a resin layer, and exposed using a mask having a plurality of bottomed hole forming patterns formed thereon, excluding portions of the resin layer corresponding to the plurality of bottomed hole forming patterns, An exposure step of making at least the surface insoluble in a developing solution, a developing step of removing portions of the resin layer corresponding to the plurality of bottomed hole forming patterns with the developing solution, and curing the resin layer A curing step of forming a resin insulating layer having a bottomed hole with the surface of the plurality of laminated substrates as the bottom, and wherein the mask has a shallower depth of the simultaneously formed bottomed hole, And large diameter The target diameter HN of the bottomed hole
Difference HN between D and the mask diameter MD of the bottomed hole forming pattern
A method for manufacturing a build-up wiring board, characterized in that the mask has the above-described bottomed hole forming pattern formed such that the mask diameter reduction amount AD given by D-MD is increased. 2. A method of manufacturing a build-up wiring board, comprising laminating a resin insulating layer on a surface of a substrate to be laminated, wherein the uncured substrate is exposed on at least the surface of the substrate to be laminated by exposure. A resin layer forming step of forming a resin layer, and a first bottomed hole forming pattern for forming a first bottomed hole having a target diameter HND1, and a first bottomed hole forming pattern having a first mask diameter MD1. And a second bottomed hole forming pattern for forming a second bottomed hole having a target diameter HND2 larger than the target diameter HND1 and the first mask diameter M
Exposure is performed using a mask on which a second bottomed hole forming pattern having a second mask diameter MD2 larger than D1 is formed, and the first bottomed hole forming pattern and the second bottomed hole forming pattern of the resin layer are exposed. Exposing at least the surface thereof to be insoluble in a developing solution except for a portion corresponding to the above, and forming the first bottomed hole forming pattern and the second bottomed hole forming pattern in the resin layer by the developing solution. A developing step of removing a corresponding portion; and a resin insulating layer having the first bottomed hole and the second bottomed hole having a depth substantially equal to a depth of the surface of the substrate to be laminated by curing the resin layer. And a curing step of forming the following. The mask is compared with the first mask diameter reduction amount AD1 given by AD1 = HND1-MD1, and AD2 = HND2-
A method of manufacturing a build-up wiring board, characterized in that the mask has the first bottomed hole forming pattern and the second bottomed hole forming pattern in which the second mask diameter reduction amount AD2 given by MD2 is large. 3. A method for manufacturing a build-up wiring board, comprising laminating a resin insulating layer on a surface of a substrate to be laminated, wherein the uncured substrate is exposed to light on at least the surface of the substrate to be laminated. A resin layer forming step of forming a resin layer; and a third bottomed hole forming pattern for forming a third bottomed hole having a target diameter HND3, the third bottomed hole forming pattern having a third mask diameter MD3. And a fourth bottomed hole forming pattern for forming a fourth bottomed hole having a target diameter HND4 substantially equal to the target diameter HND3, wherein the third mask diameter MD
Exposure is performed using a mask in which a fourth bottomed hole forming pattern having a fourth mask diameter MD4 smaller than 3 is formed, and the third bottomed hole forming pattern and the fourth bottomed hole forming pattern in the resin layer are exposed. An exposure step of exposing at least the surface thereof to insoluble in a developing solution except for a portion corresponding to the bottomed hole; and the third bottomed hole forming pattern and the fourth bottomed hole in the resin layer by the developing solution. A developing step of removing a portion corresponding to the formation pattern bottomed hole; a third bottomed hole having the surface of the laminated substrate as a bottom by curing the resin layer; A method of forming a resin insulating layer having a bottom hole. 4. The builder according to claim 1, wherein
A method of manufacturing a wiring board, wherein a plurality of developments are performed in the developing step, and
And change the direction of the build-up wiring board to be developed
Or a build-up wiring base characterized by being inverted
Plate manufacturing method.