JP2003069227A - Mask for filling resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask for filling a resin capable of completely filling a resin filling material in all through-holes in the mask for filling the resin used when a resin filling material is filled in manufacture of a multilayer printed circuit substrate. SOLUTION: The mask for filling the resin is used when the resin filling material in the through-hole formed in the manufacture of the multilayer printed circuit substrate. The mask comprises an opening at a part corresponding to the through-hole. The opening formed at the part corresponding to the through- hole having a distance to the adjacent through hole of 2.0 mm or more has an area of 1.5 to 2.5 times as wide as an area of the through-hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin filling mask.

[0002]

2. Description of the Related Art A multilayer printed wiring board, which is a so-called multilayer build-up wiring board, is manufactured by a semi-additive method or the like and has a core of 0.5 to 1.5 m.
On a resin substrate reinforced with glass cloth of about m
It is manufactured by alternately laminating conductor circuits made of copper or the like and interlayer resin insulation layers. Connection between conductor circuits via an interlayer resin insulation layer of this multilayer printed wiring board is performed by via holes.

Conventionally, build-up multilayer printed wiring boards are manufactured by the method disclosed in, for example, Japanese Patent Laid-Open No. 9-130050. That is, first, a through hole is formed in a copper clad laminate to which a copper foil is attached, and then a through hole is formed by performing an electroless copper plating process. Subsequently, the surface of the substrate is etched into a conductor pattern using a photolithography method to form a conductor circuit. Next, a roughened layer is formed on the surface of the formed conductor circuit by electroless plating or etching, and an insulating resin layer is formed on the roughened layer. An opening for a hole is formed, and then UV curing and main curing are performed to form an interlayer resin insulation layer.

Further, after roughening the interlayer resin insulation layer with an acid or an oxidizing agent, a thin electroless plating layer is formed, a plating resist is formed on the electroless plating layer, and then electrolytic plating is performed. Thickening is performed, and etching is performed after the plating resist is peeled off to form a conductor circuit. By repeating this, a build-up multilayer printed wiring board is obtained.

In the production of such a multilayer printed wiring board, when a conductor circuit is formed on a substrate, a large number of through holes will exist in the substrate immediately after the through holes are formed. Therefore, when the interlayer resin insulation layer is formed on the substrate in this state, due to the presence of the through hole, there is a recessed portion on the surface of the interlayer resin insulation layer laminated on the substrate, and the interlayer resin insulation layer is formed. There is a possibility that a conductor circuit, a via hole, etc. formed on the insulating layer may be deformed to cause a connection failure. Therefore, in order to flatten the surface of the substrate on which the conductor circuit is formed, a resin filling material is usually filled in the through hole.

For example, in Japanese Unexamined Patent Publication No. 12-261140, a mask having an opening is placed at a portion corresponding to a through hole, and a squeegee holding a resin filler is moved on the mask to open the opening of the mask. Discloses a method of filling a resin filler by pushing it into a through hole. Since this method fills the through holes with the resin filling material, it is useful as a method for solving the above-mentioned problems relating to the shape of the interlayer resin insulation layer and the connectivity of the conductor circuit and the like.

[0007]

In recent years, with the increasing frequency of IC chips and the like, there has been a demand for miniaturization and high density of multilayer printed wiring boards, which complicates the design of conductor circuits in multilayer printed wiring boards. Is coming. Along with this, the distance between adjacent through holes also becomes nonuniform.
Specifically, since the through holes are densely present immediately below the IC chip mounting portion, the distance between the through holes is short, and the vicinity of the outer edge portion of the substrate is closer to the through hole than the portion directly below the IC chip mounting portion. Because the existence of the hall is sparse,
The distance between the through holes is long. Even when manufacturing a multilayer printed wiring board having such a high-density wiring and the distance between adjacent through holes is uneven, as described above, the method of filling the through holes with the resin filling material is This is useful in that a multi-layer printed wiring board having more excellent connection reliability can be manufactured.

However, when a through hole is filled with a resin filler in the manufacture of a multilayer printed wiring board having high-density wiring, the through hole overlaps with the through hole as disclosed in Japanese Patent Laid-Open No. 12-261140. When a mask having an opening in a portion is used, a through hole which is not completely filled with the resin filler may occur. In particular, it has been difficult to completely fill the resin filling material into the through holes having a long distance from the adjacent through holes.

[0009]

Therefore, the present inventors have
As a result of diligent studies to solve the above problems, the area of the opening formed in the portion corresponding to the through hole having a long distance from the adjacent through hole has a larger mask area than the area of the through hole, or the above through hole. By using a mask in which an opening formed in a portion corresponding to the above has a through hole in its periphery, a through hole having a long distance from an adjacent through hole can be completely filled with the through hole. It was found that a sufficient amount of the resin filler can be filled in, and the present invention having the following contents as the gist constitution was completed.

That is, the resin filling mask of the first aspect of the present invention is a resin filling mask used when filling a resin filling material into a through hole formed in the manufacture of a multilayer printed wiring board. The filling mask has an opening formed in a portion corresponding to the through hole, and the distance between adjacent through holes in the opening is 2.0.
The area of the opening formed in the portion corresponding to the through hole having a thickness of at least 1.5 mm is 1.5 to 2.
It is characterized by being 5 times.

The resin filling mask of the second aspect of the present invention is a resin filling mask used when filling a resin filling material into a through hole formed in the production of a multilayer printed wiring board. The filling mask has an opening formed in a portion corresponding to the through hole, and the distance between adjacent through holes in the opening is 2.0.
An opening formed in a portion corresponding to a through hole having a size of less than mm has an area of 0.1 mm or less of the area of the opening.
It is characterized in that it has at least one through hole that is at least twice as long as less than 1.0 times.

In the resin filling mask according to the first or second aspect of the present invention, the through hole is preferably a through hole formed to connect lower layer conductor circuits sandwiching the substrate. In the resin filling mask, it is desirable that the portion corresponding to the lower layer conductor circuit non-forming portion on the substrate also has an opening.

In the resin filling mask according to the first or second aspect of the present invention, the through hole is formed to connect at least an upper conductor circuit sandwiching a substrate and an interlayer resin insulation layer. In this resin filling mask, an opening is also provided in a portion corresponding to the upper conductor circuit non-forming portion on the interlayer resin insulation layer and a portion corresponding to a via hole formed in the interlayer resin insulation layer. Is desirable.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION First, a resin filling mask of the first invention will be described. The resin filling mask of the first invention is a resin filling mask used when filling a resin filling material into a through hole formed in the production of a multilayer printed wiring board, wherein the resin filling mask is An opening is formed in a portion corresponding to the through hole, and the opening formed in a portion of the opening corresponding to a through hole having a distance of 2.0 mm or more between adjacent through holes is Area is 1.5 of the through hole area
It is characterized by being ~ 2.5 times.

The resin filling mask according to the first aspect of the present invention is formed in a portion corresponding to a through hole having a distance of 2.0 mm or more from an adjacent through hole in an opening portion of the resin filling mask. Since the area of the opening is 1.5 to 2.5 times the area of the through hole, which is sufficiently larger than the area of the through hole, this resin filling mask is used when manufacturing a multilayer printed wiring board. By using it, all the through holes can be completely filled with the resin filler.

Distance between adjacent through holes is 2.0 mm
When the resin filler is filled into the above through holes by using a mask having an opening having a shape substantially the same as the shape of the through holes, some through holes cannot be completely filled with the resin filler. There is. The reason for this is not clear, but it is thought to be due to the following reasons. That is, when the resin filler is filled, the resin filler is pushed into the through hole from the opening while moving the squeegee holding the resin filler on the mask. When a resin filling material is filled in a through hole having a short distance (less than 2.0 mm) from the hole, the squeegee pressure is uniformly applied to the plurality of openings, but the distance from the adjacent through hole is large. When a resin filler is filled in a long through hole (2.0 mm or more), there is no other opening near the opening corresponding to this through hole, so a squeegee is pushed into this opening. It is considered that the pressure is likely to concentrate, and as a result, the resin filler is not completely filled in the through hole having a long distance (2.0 mm or more) from the adjacent through hole, and a depression is likely to occur.

When a through hole that is not completely filled with the resin filling material and a through hole that is completely filled with the resin filling material are formed in this manner, the following inconvenience occurs. That is, when manufacturing a multilayer printed wiring board, a resin filler is filled in the through holes, and then the resin filler is cured to form a resin filler layer. Here, the volume of the cured resin filler is usually larger than that of the uncured resin filler. Therefore, the resin filler after the curing treatment has a shape in which the surface layer portion is raised from the through hole. So usually,
After the resin filler is semi-cured (cured by about 60 to 70%), the entire surface of the substrate is polished, and then the resin filler is completely cured to fill the surface layer with a flat resin. A material layer is formed.

However, as described above, when the through hole completely filled with the resin filler and the through hole not completely filled with the resin filler coexist, a curing treatment (semi-curing treatment) is performed. Since the volume of the resin filler that increases at that time is different, the degree of swelling from the through hole is different, and there are a large swelled portion and a little swelled portion. Therefore, when performing a polishing process that completely removes a large swelled portion, the less swelled portion is dented, and the conductor circuit around the less swelled portion is also polished and becomes conductive. It may cause a defect. On the other hand, if the polishing treatment is performed to the extent that the portion that does not rise so much is completely removed, the portion that greatly rises is not completely polished, and when an interlayer resin insulation layer is further laminated, undulations and This may cause the formation of surface depressions.

In the resin filling mask of the first aspect of the present invention, as described above, the opening formed for filling the resin filling material into the through hole having a long distance from the adjacent through hole has the area thereof. Through-hole area 1.5 to 2.5
Double the size of the through hole, which is larger than the area of the through hole and has a long distance between adjacent through holes. It is also possible to fill a sufficient amount of resin filler into the through holes. In addition, all the through holes can be completely filled with the resin filling material. in this way,
When all the through holes are completely filled with the resin filler, the volume that increases during the curing process is about the same, and the entire surface can be planarized by performing the polishing process.

The distance between the adjacent through holes is 2.0.
If the area of the opening formed in the portion corresponding to the through hole of mm or more is less than 1.5 times the area of the through hole, the mask is filled with the resin filler in an amount capable of completely filling the through hole. It is not possible to fill the through hole, and the filling of the through hole becomes incomplete. On the other hand, 2.
If it exceeds 5 times, the through hole can be completely filled with the resin filling material, but since the resin filling material is filled through the mask in an amount larger than that required to fill the through hole, an extra amount is required. Such a resin filling material may adhere to the periphery of the through hole, or the surface layer portion of the filled resin filling material may have a greatly raised shape. In this case, if the excess resin filler cannot be sufficiently removed in the subsequent polishing process, it may cause undulations in the laminated interlayer resin insulation layer, and also cause a problem in the area around the through hole. It is not easy to completely remove the excess resin filler existing only in the part.

The distance between adjacent through holes is 2.
The through hole having a size of less than 0 mm can be completely filled with the resin filler by using a mask having an opening having substantially the same shape as the through hole. Here, “substantially the same shape” means a shape that is similar to the shape of the cross section of the through hole (usually circular) and has an area within the range of ± 30% of the area of the through hole.

In the present specification, the area of the opening of the resin filling mask means the area of the opening when the resin filling mask is viewed in plan, and the area of the through hole means the through hole. The area of the void portion existing in the center of the through hole when the substrate in which the hole is formed is viewed in plan.

The through hole for filling the resin filling material using the resin filling mask of the first aspect of the present invention is specifically a through hole formed for connecting lower layer conductor circuits sandwiching the substrate. And at least a through hole formed for connecting at least the upper conductor circuit circuit sandwiching the substrate and the interlayer resin insulation layer.

In the resin filling mask, an opening is formed in a portion corresponding to the lower layer conductor circuit non-forming portion on the substrate, or an upper layer conductor circuit non-forming portion on the interlayer resin insulation layer is formed. It is desirable that openings are also formed in the corresponding portions and the portions corresponding to the via holes formed in the interlayer resin insulation layer. These will be described in detail when the method for manufacturing a multilayer printed wiring board using the resin filling mask of the present invention is described.

The material of the resin filling mask is not particularly limited, and examples thereof include metals such as nickel alloys, nickel-cobalt alloys and SUS; and plastics such as epoxy resins and polyimide resins. The method for manufacturing the resin filling mask is not particularly limited, and examples thereof include etching processing, additive processing, and laser processing.

Further, the resin filler to be filled in the through hole using the resin filling mask is not particularly limited, and examples thereof include epoxy resins such as A type and F type bisphenol type epoxy resins, and imidazole type curing agents. And the like, and those containing inorganic particles such as an aluminum compound and a calcium compound.

In addition to the above epoxy resin and the like, the resin filler contains thermosetting resin such as polyimide resin and phenol resin, and thermoplastic resin such as fluororesin and polyolefin resin. Alternatively, these resins may be contained in place of the epoxy resin.

The resin filling mask of the first aspect of the present invention having such a structure can be suitably used when filling the resin filling material in the production of a multilayer printed wiring board. The method for manufacturing a multilayer printed wiring board using the resin filling mask of the first aspect of the present invention will be described in detail later.

Next, the resin filling mask of the second invention will be described. The resin filling mask of the second invention is
A resin filling mask used for filling a resin filling material into a through hole formed in the manufacture of a multilayer printed wiring board, wherein the resin filling mask has an opening at a portion corresponding to the through hole. The distance between adjacent through holes in the above openings is 2.0 mm.
The opening formed in the portion corresponding to the above through hole has at least one through hole having an area of 0.1 times or more and less than 1.0 times the area of the opening around the opening. It is characterized by

The resin filling mask of the second aspect of the present invention is formed in a portion corresponding to a through hole having a distance of 2.0 mm or more from an adjacent through hole in an opening portion of the resin filling mask. Since the through-hole having an area of 0.1 times or more and less than 1.0 times the area of the opening is formed around the opening, the resin filler is provided through the through-hole together with the opening. Is pushed into the through hole. Therefore, it is possible to fill the resin filling material through the mask in an amount capable of completely filling the through hole, and by using this resin filling mask when manufacturing a multilayer printed wiring board, The through hole can be completely filled with the resin filler. In this way, when all the through holes are completely filled with the resin filler, the volume that increases during the curing treatment (semi-curing treatment) is about the same as described above, and the entire surface is polished. Therefore, flattening can be achieved.

The distance between the adjacent through holes is 2.0.
The area of the through hole around the opening formed in the portion corresponding to the through hole having a size of at least 0.1 mm is 0.
If it is less than 1 time, the area of the through hole is too small, so that the resin filler cannot be easily removed and the resin filler cannot be pushed into the through hole through the through hole. Can't get On the other hand, when it is 1.0 times or more, the through hole can be completely filled with the resin filling material, but a large amount of the resin filling material adheres to or is filled in the portion other than the through hole (around the through hole). The surface layer portion of the resin filler may have a largely raised shape, and in this case, it may be difficult to sufficiently remove the excess resin filler in the subsequent polishing process.

Also in the resin filling mask of the second aspect of the present invention, like the resin filling mask of the first aspect of the present invention, the through hole whose distance from the adjacent through hole is less than 2.0 mm is the through hole. It is possible to completely fill the through hole with the resin filling material by using a mask having an opening having substantially the same shape as the above.

In the resin filling mask of the second aspect of the present invention, the opening formed in the portion corresponding to the through hole may have substantially the same shape as the through hole. Further, the number of the through holes is not particularly limited, and may be appropriately selected in consideration of the distance between the through hole filled with the resin filler through the through hole and the through hole adjacent to the through hole. However, normally, about 1 to 8 is desirable.

Further, it is preferable that the through holes are formed uniformly along the outer periphery of the opening. The distance between the through hole and the opening is 0.1
It is desirable to be 0.5 mm. If it is less than 0.1 mm, the distance between the through hole and the opening is too short, and the mechanical strength of the resin filling mask at that location is reduced. When the resin filling material is filled with the resin filling mask, the resin filling mask may be damaged. On the other hand, if it exceeds 0.5 mm, the distance between the through hole and the opening is too long, so that the through hole to be filled may not be filled with the resin filler. Further, the distance between the through hole and the opening is more preferably 0.1 to 0.3 mm. This is because the composition and viscosity of the resin filler are not so much affected. The distance between the through hole and the opening means the shortest distance between the outer edge portions of both.

As a concrete example of the through hole for filling the resin filling material using the resin filling mask of the second aspect of the present invention,
Similar to the through hole filled with the resin filler using the resin filling mask of the first aspect of the present invention, the through hole formed for connecting the lower layer conductor circuits sandwiching the substrate, or at least the substrate and the interlayer resin insulation Examples thereof include through holes formed to connect upper layer conductor circuits sandwiching the layers. Also in the resin filling mask of the second aspect of the present invention, an opening is formed in a portion corresponding to the lower conductor circuit non-forming portion on the substrate, or an upper conductor circuit non-forming portion on the interlayer resin insulation layer is not formed. It is desirable that openings are also formed in a portion corresponding to the forming portion and a portion corresponding to a via hole formed in the interlayer resin insulation layer.

As the material of the resin filling mask of the second aspect of the present invention and the manufacturing method thereof, the same methods as those of the resin filling mask of the first aspect of the present invention can be mentioned. The resin filling mask of the second aspect of the present invention having such a configuration can also be suitably used when filling a resin filling material in the production of a multilayer printed wiring board. The method for manufacturing a multilayer printed wiring board using the second resin filling mask of the present invention will be described later.

Next, a method of manufacturing a multilayer printed wiring board using the resin filling masks of the first and second aspects of the present invention will be described. Of course, the manufacturing method of the multilayer printed wiring board using the resin filling mask of the first and second aspects of the present invention is not limited to the following manufacturing method.

(1) First, using an insulating substrate as a starting material,
A lower layer conductor circuit is formed on the insulating substrate. Examples of the insulating substrate include a glass epoxy substrate, a polyester substrate, a polyimide substrate, a bismaleimide-triazine resin substrate, a copper clad laminate, and an RCC substrate.
The lower layer conductor circuit can be formed, for example, by forming a solid conductor layer on the surface of the insulating substrate by electroless plating or the like, and then performing etching. Alternatively, the copper clad laminate or the RCC substrate may be formed by etching.

When the lower layer conductor circuits sandwiching the insulating substrate are connected by through holes, for example, a through hole is formed in the insulating substrate by using a drill, a laser or the like, and then electroless. A through hole can be formed by performing a plating process.

(2) Next, when a through hole is formed in the above step (1), a resin filler is filled in the through hole. In this step, the resin filling mask of the first or second aspect of the present invention can be used. Specifically, after mounting the resin filling mask of the first or second invention on a substrate, a squeegee holding a resin filling is pressed against the resin filling mask, and the squeegee is the resin filling mask. By moving it upward, the resin filling material is filled into the through hole through the opening of the mask. The resin filler described above can be used as the resin filler.

Further, in this step, a resin filling mask having an opening at a portion corresponding to the through hole and an opening at a portion corresponding to the lower layer conductor circuit non-forming portion is used, and at the same time, the lower layer is formed. It is desirable that the conductor circuit non-formation portion is also filled with the resin filler. By filling the lower-layer conductor circuit non-formation part with the resin filler, the entire surface becomes flat when the polishing process is performed later, so that the interlayer resin insulation layer formed in a later step has a swell or a surface. This is because depressions are less likely to occur.

The shape of the opening corresponding to the lower layer conductor circuit non-formed portion may be substantially the same as the shape of the lower layer conductor circuit non-formed portion. In a multilayer printed wiring board having high-density wiring, L / S (width of conductor circuit / distance between conductor circuits) is about 25/25 to 75/75, and the distance between adjacent conductor circuits is equal to that of adjacent through circuits. Short compared to the distance between the holes. However, since the lower conductor circuit non-forming portion has a depth of about several μm to several tens of μm, the amount of the resin filler filled in the lower conductor circuit non-forming portion is the same as that of the resin filler filling the through hole. Much less than the quantity. Therefore, even if the shape of the opening of the portion corresponding to the lower layer conductor circuit non-formed portion formed in the resin filling mask is substantially the same as the shape of the lower layer conductor circuit non-formed portion, the lower layer conductor circuit is not formed. The part can be completely filled with the resin filler.

First, the resin filling mask is used to fill only the through holes with a resin filling mask having openings only in the portions corresponding to the through holes, and thereafter, the portions corresponding to the lower layer conductor circuit non-forming portion. The resin filling material may be filled in the lower conductor circuit non-forming portion using a resin filling mask having only the opening.

After the resin filler is filled, the resin filler is dried to a semi-cured state (cured state of 60 to 70%) and further cured to form a resin filler layer. . The semi-cured state of the resin filler is such that if the resin filler is completely cured, it becomes difficult to carry out polishing, while if the semi-curing is insufficient, foreign matter is contained in the resin filler layer during polishing. This may cause the interlayer limb insulating layer to swell and the resin filler layer to peel off. The drying can be performed, for example, under the condition of 100 ° C./20 minutes. Further, the curing treatment can be performed at a temperature of, for example, 50 to 250 ° C., and step curing may be performed in which the temperature is changed from a low temperature to a high temperature for curing.

Since the resin filler layer formed through the drying process as described above has many portions higher than the height of the conductor circuit as described above, polishing is performed to form the resin filler layer. The both main surfaces of the substrate are flattened by grinding. Also,
When the resin filler layer is also formed on the outer edge of the lower conductor circuit, the surface of the lower conductor circuit is also polished in this step.

The above-mentioned polishing is performed by belt sander polishing using polishing paper, buff polishing using a polishing agent, jet scrubbing, or the like. Among these, it is desirable to roughly polish with a belt sander or the like, and then to carry out buffing using fine abrasive grains. Further, when the resin filler is easily polished (for example, when the blending amount of inorganic particles is small), it is also desirable to achieve the flattening only by buffing using fine abrasive grains. This is because the surface of the substrate is less likely to be damaged.

In this step, a roughened surface may be formed on the wall surface of the through hole or the surface of the lower layer conductor circuit before the resin filling material is filled. This is because the adhesion between the through hole or the lower conductor circuit and the resin filler layer is improved. As a method of forming the roughened surface, for example, blackening (oxidation) -reduction treatment, etching treatment, Cu-Ni-
Examples include treatment with P needle-shaped alloy plating.

(3) Next, an uncured resin composed of a thermosetting resin or a resin composite containing a thermosetting resin and a thermoplastic resin is provided on the substrate on which the lower conductor circuit and the resin filler layer are formed. A layer is formed, or a resin layer made of a thermoplastic resin is formed. The uncured resin layer, uncured resin is applied by a roll coater, curtain coater, or the like,
It can be formed by thermocompression bonding an uncured (semi-cured) resin film. Further, the resin layer made of the above-mentioned thermoplastic resin can be formed by thermocompression bonding a resin molded body molded on the film.

Examples of the thermosetting resin include epoxy resin, phenol resin, polyimide resin, polyester resin, bismaleimide resin, polyolefin resin, and polyphenylene ether resin.

Examples of the thermoplastic resin include phenoxy resin, polyether sulfone, polysulfone and the like. The resin composite is not particularly limited as long as it contains a thermosetting resin and a thermoplastic resin, and examples thereof include a resin composition for forming a roughened surface.

The above-mentioned roughened surface-forming resin composition is, for example, in an uncured heat-resistant resin matrix which is hardly soluble in a roughening liquid consisting of at least one selected from acids, alkalis and oxidizers. Examples thereof include those in which a substance soluble in a roughening liquid containing at least one selected from an acid, an alkali and an oxidizing agent is dispersed. It should be noted that the terms "poorly soluble" and "soluble" are referred to as "soluble" for the sake of convenience, and those having a relatively high dissolution rate when immersed in the same roughening solution for the same time are referred to as "relatively soluble". The slow one is called "poorly soluble" for convenience.

The heat-resistant resin matrix is preferably one that can maintain the shape of the roughened surface when the roughened surface is formed in the interlayer resin insulating layer by using the roughening liquid. Examples thereof include curable resins, thermoplastic resins, and composites of these. Examples of the soluble substance include inorganic particles, resin particles, metal particles, rubber particles, liquid phase resin, liquid phase rubber, and the like.

(4) Next, in the case of forming an interlayer resin insulation layer using a thermosetting resin or a resin composite as a material thereof, the uncured resin insulation layer is subjected to a curing treatment and also for via holes. An opening is formed to serve as an interlayer resin insulation layer. Further, in this step, a through hole may be formed, if necessary. The via hole opening is preferably formed by laser processing. When a photosensitive resin is used as the material of the interlayer resin insulation layer, it may be formed by exposure and development processing.

When forming an interlayer resin insulation layer using a thermoplastic resin as its material, a via hole opening is formed in the resin layer made of the thermoplastic resin to form an interlayer resin insulation layer. In this case, the via hole opening can be formed by performing laser processing. Also,
When the through hole is formed in this step, the through hole may be formed by drilling, laser processing, or the like.

(5) Next, an upper conductor circuit is formed on the surface of the interlayer resin insulation layer including the inner wall of the via hole opening. In forming the upper layer conductor circuit, first, a thin film conductor layer is formed on the surface of the interlayer resin insulation layer. The thin film conductor layer can be formed by a method such as electroless plating or scatterer. A roughened surface may be formed on the surface of the interlayer resin insulation layer before forming the thin film conductor layer. By forming the roughened surface, the adhesion between the interlayer resin insulation layer and the thin film conductor layer can be improved.

When the through hole is formed in the above step (4), the thin film conductor layer is formed on the wall surface of the through hole when the thin film conductor layer is formed on the interlayer resin insulation layer. It may be a through hole.

(6) Next, a plating resist is formed on the substrate having an electroless plating film formed on its surface. The plating resist can be formed, for example, by sticking a photosensitive dry film or applying a liquid resist, and then exposing and developing the liquid resist.

Then, electroplating is performed using the electroless plated film as a plating lead to form an electroplated layer on the plating resist non-forming portion. After that, the above-mentioned plating resist and the electroless plating film and the thin film conductor layer under the plating resist are removed to form an upper conductor circuit (including a via hole). Further, after forming this plating resist, instead of forming the electroplating layer, an electroplating layer is formed on the entire surface of the thin film conductor layer, and then an etching process is applied to form the upper conductor circuit. May be.

(7) Next, when a through hole is formed in the above steps (4) and (5), a resin filler is filled in the through hole. In this process,
The resin filling mask of the first or second aspect of the present invention can be used. Specifically, after attaching the resin filling mask of the first or second present invention on the interlayer resin insulation layer, the squeegee holding the resin filler is pressed against the resin filling mask, and the squeegee is attached to the resin. By moving on the filling mask, the resin filling material is filled into the through hole through the opening of the mask.

Further, in this step, an opening is formed in the portion corresponding to the through hole, and an opening is also formed in the portion corresponding to the upper conductor circuit non-forming portion and / or the portion corresponding to the via hole. It is desirable to use a resin filling mask and at the same time fill the upper conductor circuit non-forming portion and the via hole with the resin filling material.
By filling the resin filling material also in the upper layer conductor circuit non-formed portion and in the via hole, the entire surface becomes flat when the subsequent polishing treatment is performed, and the interlayer resin insulation layer or This is because waviness and surface depressions are less likely to occur in the solder resist layer.

The shapes of the openings corresponding to the upper conductor circuit non-formation portion and the via hole may be substantially the same as the shapes of the upper conductor circuit non-formation portion and the via hole, respectively. The reason for this is that the shape of the opening of the resin filling mask used when filling the lower conductor circuit non-forming portion with the resin filler is substantially the same as the shape of the lower conductor circuit non-forming portion. The reason is the same.

First, a resin filling mask is used to fill only the through holes with a resin filling mask having openings only in the portions corresponding to the through holes, and thereafter, if necessary, the upper layer conductor circuit is not formed. The resin filling material may be filled in the upper layer conductor circuit non-formed portion or the via hole by using a resin filling mask having an opening only in the portion corresponding to the portion or the via hole. The resin filler to be filled here may be the same as the resin filler used in the above step (2).

After the resin filler is filled, the resin filler is dried as in the step (2), and further,
A resin filler layer is obtained by performing a curing treatment. In addition,
Since the dried resin filler layer is higher than the height of the upper conductor circuit as described above, polishing is performed and the resin filler layer is ground to flatten both main surfaces of the substrate. Here, the polishing treatment can be performed by the same method as the method used in the step (2).

Further, after the above-mentioned polishing treatment, the surface layer portion of the resin filler and the surface of the upper conductor circuit are substantially flattened, and if necessary, electroless plating is performed, so that the surface portion of the resin filler layer is formed. You may form the cover plating layer which covers. The lid plating layer may be formed by performing sputtering instead of electroless plating, or by performing electroless plating or sputtering and then electrolytic plating to form a two-layer lid plating layer. May be. By forming the lid plating layer, the via hole can be formed immediately above the through hole. When the via hole is filled with the resin filler, a lid plating layer may be formed to cover the resin filler layer in the via hole. By forming the lid plating layer, the via hole can be formed immediately above the via hole.

Also in this step, a roughened surface may be formed on the wall surface of the through hole or the surface of the upper conductor circuit (including the wall surface of the via hole) before the resin filling material is filled. This is because the adhesion between the through hole or upper conductor circuit and the resin filler layer is improved. As a method of forming the roughened surface, for example, blackening (oxidation) -reduction treatment,
Examples thereof include etching treatment and treatment with Cu-Ni-P needle-shaped alloy plating.

(8) Next, when the lid plating layer is formed, the surface of the lid plating layer is roughened if necessary, and the steps (3) to (7) are repeated. As a result, the interlayer resin insulation layer and the upper layer conductor circuit are laminated on both surfaces thereof. In addition, in this step, the through hole may or may not be formed.

(9) Next, a solder resist layer is formed on the surface of the substrate including the uppermost conductor circuit, the solder resist layer is opened to form a solder pad, and a solder paste is applied to the solder pad. Solder bumps are formed by filling and reflowing. After that, PGA (Pin Grid Array) or BGA (Ball G) is provided by arranging pins or forming solder balls on the external board connecting surface.
rid Array).

The solder resist layer can be formed using a solder resist composition made of, for example, polyphenylene ether resin, polyolefin resin, fluororesin, thermoplastic elastomer, epoxy resin, polyimide resin or the like.

As the solder resist composition other than the above, for example, (meth) acrylate of novolac type epoxy resin, imidazole curing agent, bifunctional (meth) acrylic acid ester monomer, molecular weight 500 to 50.
A (meth) acrylic acid ester polymer of about 00, a thermosetting resin composed of a bisphenol type epoxy resin, a photosensitive monomer such as a polyvalent acrylic monomer, a paste-like fluid containing a glycol ether solvent, etc. The viscosity is preferably adjusted to 1 to 10 Pa · s at 25 ° C.

As a method of forming the opening in the solder resist layer, for example, the same method as the method of forming the opening for via hole, that is, the method of irradiating with laser light can be used. At this time, examples of the laser used include a carbon dioxide (CO ₂ ) laser, an ultraviolet laser, an excimer laser, and the like.

The upper conductor circuit portion exposed by opening the solder resist layer is usually desirably covered with a corrosion-resistant metal such as nickel, palladium, gold, silver or platinum. Specifically, nickel-gold, nickel-silver, nickel-palladium, nickel-palladium-
It is desirable to form the coating layer with a metal such as gold. The coating layer can be formed by, for example, plating, vapor deposition, electrodeposition, or the like. Among these, plating is preferable because of excellent uniformity of the coating layer.

Further, the solder pump is provided with a mask having an opening formed in a portion corresponding to the solder pad,
It is formed by filling the solder pad with solder paste and then reflowing. The solder paste is not particularly limited, and those generally used in the production of printed wiring boards can be used. Specifically, for example, S
n: Pb (weight ratio) = 63: 37, Sn: Pb: Ag =
Examples include 62: 36: 2, Sn: Ag = 96.5: 3.5, and the like, Sn and Sb, and the like.

Plasma processing with oxygen, carbon tetrachloride, or the like may be performed at appropriate times for a character printing process for forming product recognition characters or the like or for modifying the solder resist layer. Although the above method is based on the semi-additive method, the full-additive method may be adopted.

[0074]

The present invention will be described in more detail below. (Example 1) A. Preparation of resin film for interlayer resin insulation layer Bisphenol A type epoxy resin (epoxy equivalent 46
9, Epicort 1001) 30 manufactured by Yuka Shell Epoxy Co., Ltd.
40 parts by weight, cresol novolac type epoxy resin (epoxy equivalent 215, Epicron N-673 manufactured by Dainippon Ink and Chemicals, Inc.), triazine structure-containing phenol novolac resin (phenolic hydroxyl equivalent 120, Dainippon Ink and Chemicals Feno Light KA-705
2) 30 parts by weight of 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha were dissolved by heating while stirring, and epoxidized polybutadiene rubber having a terminal end (Denalex R-45 EPT manufactured by Nagase Kasei Kogyo Co., Ltd.)
Epoxy resin composition containing 15 parts by weight, 1.5 parts by weight of 2-phenyl-4,5-bis (hydroxymethyl) imidazole pulverized product, 2 parts by weight of finely pulverized silica, and 0.5 parts by weight of silicon-based defoaming agent. Was prepared. The obtained epoxy resin composition was applied onto a PET film having a thickness of 38 μm by a roll coater so that the thickness after drying was 50 μm, and then dried at 80 to 120 ° C. for 10 minutes to obtain an interlayer resin. A resin film for an insulating layer was produced.

B. Preparation of Resin Filler 100 parts by weight of bisphenol F type epoxy monomer (Made by Yuka Shell Co., molecular weight: 310, YL983U), the surface of which is coated with a silane coupling agent has an average particle diameter of 1.6 μm and a maximum particle diameter. Is less than 15 μm
iO ₂ spherical particles (manufactured by Adtech, CRS 1101-
72 parts by weight of CE) and 1.5 parts by weight of a leveling agent (Perenol S4 manufactured by San Nopco Co.) were placed in a container and mixed by stirring to give a viscosity of 30 to 80 at 23 ± 1 ° C.
A Pa · s resin filler was prepared. As a curing agent, an imidazole curing agent (2E4MZ-manufactured by Shikoku Kasei Co., Ltd.
(CN) 6.5 parts by weight was used.

C. Manufacture of multilayer printed wiring board (1) 0.8mm thick glass epoxy resin or BT
A copper clad laminate having 18 μm of copper foil 8 laminated on both surfaces of an insulating substrate 1 made of (bismaleimide triazine) resin was used as a starting material (see FIG. 1A). First,
This copper clad laminate is drilled to form a through hole having a diameter of 350 μm, electroless plating is performed, and pattern etching is performed to form the lower conductor circuit 4 and the through hole 9 on both sides of the substrate. did. Among the through holes 9 formed in this step, the through holes existing near the center of the substrate have a distance of 650 from the adjacent through holes.
The through hole existing in the vicinity of the outer edge of the substrate has a distance of 2.0 mm from the adjacent through hole. In addition, all the through holes have a conductor layer thickness of 25 μm,
The diameter of the void existing in the center of the through hole is 300 μm
Is.

(2) The substrate on which the through holes 9 and the lower conductor circuit 4 are formed is washed with water and dried, and then NaOH is used.
(10 g / l), NaClO ₂ (40 g / l), Na ₃
Blackening treatment using an aqueous solution containing PO ₄ (6 g / l) as a blackening bath (oxidizing bath), and NaOH (10 g / l), Na
Reduction treatment using an aqueous solution containing BH ₄ (6 g / l) as a reduction bath was performed to form roughened surfaces 4 a and 9 a on the entire surface of the lower conductor circuit 4 including the through holes 9 (see FIG. 1 (b)). ).

(3) After the resin filler described in the above B is prepared, the lower layer conductor circuit non-forming portion and the lower layer in the through hole 9 and on one surface of the substrate 1 and the lower layer are prepared within 24 hours after the preparation by the following method. Resin filling material 10 'on the outer edge of the conductor circuit 4
Layers were formed. That is, a resin filling mask having an opening at a portion corresponding to a through hole and a lower conductor circuit non-forming portion is placed on a substrate, and a squeegee is used to form a lower conductor circuit not forming a recess in the through hole. Part and the outer edge of the lower conductor circuit were filled with the resin filler 10 'and dried (semi-cured) under the condition of 100 ° C./20 minutes (see FIG. 1 (c)).

The opening in the resin filling mask corresponding to the through hole in the vicinity of the center of the substrate has a diameter of 300 μm and corresponds to the through hole in the vicinity of the outer edge of the substrate. The diameter of the opening in the portion is 400 μm (about 1.78 times the area of the through hole).

(4) Buffing is performed on both surfaces of the substrate that has been subjected to the treatment of (3) above so that the resin filler 10 'is not left on the outer edge of the lower conductor circuit 4 or the land of the through hole 9. And the surface of the resin filler was made flat. Then, heat treatment was performed at 100 ° C. for 1 hour and at 150 ° C. for 1 hour to cure the resin filler 10 ′.

In this manner, the surface layer portion of the resin filler layer 10 and the surface of the lower conductor circuit 4 formed in the through hole 9 and the lower conductor circuit non-forming portion are flattened, and the resin filler layer 10 and the lower conductor circuit 10 are flattened. 4 was firmly adhered to the side surface 4a of the through-hole 4 via the roughened surface, and the inner wall surface 9a of the through hole 9 was firmly adhered to the resin filler layer 10 via the roughened surface (FIG. 1). (See (d)). That is, by this step, the surface of the resin filler layer 10 and the surface of the lower conductor circuit 4 become substantially flush with each other.

(5) After washing the above substrate with water and acid degreasing,
By soft etching and then spraying an etching solution on both surfaces of the substrate to etch the surface of the lower conductor circuit 4, the land surface of the through hole 9 and the inner wall, the entire surface of the lower conductor circuit 4 is roughened. Surface 4a, 9a
Was formed (see FIG. 2A). As the etching solution, an etching solution (Mec Etch Bond, manufactured by Mec Co., Ltd.) containing 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride was used.

(6) A resin film for an interlayer resin insulation layer, which is slightly larger than the substrate prepared in A, is placed on both sides of the substrate, and the pressure is 0.4 MPa, the temperature is 80 ° C., and the pressure bonding time is 1
After being temporarily pressure-bonded and cut under the condition of 0 second, the interlayer resin insulating layer 2 was formed by further bonding and curing using a vacuum laminator device by the following method (see FIG. 2B). . That is, the resin film for the interlayer resin insulation layer is placed on the substrate, the degree of vacuum is 67 Pa, the pressure is 0.4
Main pressure bonding was performed under conditions of a, temperature of 80 ° C., and pressure bonding time of 60 seconds, and then heat cured at 170 ° C. for 30 minutes.

(7) Next, a beam diameter of 4.0 was obtained with a CO ₂ gas laser having a wavelength of 10.4 μm through a mask in which a through hole having a thickness of 1.2 mm was formed on the interlayer resin insulation layer 2.
mm, top hat mode, pulse width 8.0 μsec, mask through-hole diameter 1.0 mm, and one-shot condition, the via hole opening 6 having a diameter of 80 μm was formed in the interlayer resin insulating layer 2 (see FIG. See c)).

(8) The substrate having the via hole openings 6 formed therein is immersed in a solution containing 60 g / l of permanganate at 80 ° C. for 10 minutes to remove the epoxy resin particles existing on the surface of the interlayer resin insulation layer 2. The surface of the interlayer resin insulation layer 2 including the inner wall of the via hole opening 6 was roughened by dissolution and removal (see FIG. 2D).

(9) Next, the substrate after the above treatment was immersed in a neutralizing solution (made by Shipley Co., Ltd.) and washed with water. Further, by applying a palladium catalyst to the surface of the substrate that has been roughened (roughening depth 3 μm), catalyst nuclei are attached to the surface of the interlayer resin insulating layer 2 and the inner wall surface of the via hole opening 6. (Not shown). That is, the above-mentioned substrate is placed on palladium chloride (PdCl ₂ ) and stannous chloride (SnC
The catalyst was applied by immersing it in a catalyst solution containing 1 ₂ ) and precipitating palladium metal.

(10) Next, the substrate to which the catalyst is applied is immersed in an electroless copper plating solution having the following composition to form an electroless copper plating film having a thickness of 0.6 to 3.0 μm on the entire rough surface. 12 was formed to obtain a substrate in which the electroless copper plating film 12 was formed on the surface of the interlayer resin insulation layer including the inner wall of the via hole opening (see FIG. 3A). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l Tartaric acid 0.200 mol / l Copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α′-bipyridyl 100 mg / l polyethylene glycol (PEG) 0.10 g / l [electroless plating conditions] 40 minutes at a liquid temperature of 34 ° C

(11) A commercially available photosensitive dry film is attached to the substrate on which the electroless copper-plated film 12 is formed, a mask is placed, and exposure is carried out at 100 mJ / cm ² to obtain 0.8%.
The plating resist 3 having a thickness of 20 μm was provided by developing with an aqueous solution of sodium carbonate (see FIG. 3B).

(12) Next, the substrate is washed with water at 50 ° C. to degrease it, washed with water at 25 ° C., and further washed with sulfuric acid, and then electrolytic plating is performed under the following conditions to remove the plating resist 3 An electrolytic copper-plated film 13 having a thickness of 20 μm was formed on the formation portion (see FIG. 3C). [Electrolytic plating solution] Sulfuric acid 2.24 mol / l Copper sulfate 0.26 mol / l Additive 19.5 ml / l (Akatech Japan Co., Ltd., Kaparaside GL) [Electrolytic plating conditions] Current density 1 A / dm ² hours 65 minutes temperature 22 ± 2 ℃

(13) Furthermore, the plating resist 3 is 5%.
After stripping and removing with KOH, the electroless plated film under the plating resist 3 is subjected to etching treatment with a mixed solution of sulfuric acid and hydrogen peroxide to dissolve and remove it, and an independent upper conductor circuit 5 (including via hole 7) is formed. (See FIG. 3D).

(14) Then, the same treatment as in the above (5) was performed to form a roughened surface on the surface of the upper conductor circuit (FIG. 4).
(See (a)).

(15) By repeating the steps (6) to (14), a conductor circuit in an upper layer is formed to obtain a multilayer wiring board (see FIGS. 4 (b) to 5 (b)). .

(16) Next, a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) to a concentration of 60% by weight was acrylated with 50% epoxy groups. Oligomer for imparting sex (molecular weight: 4000) 46.6
7 parts by weight, 80% by weight dissolved in methyl ethyl ketone
Bisphenol A type epoxy resin (made by Yuka Shell Co.,
Trade name: Epicoat 1001) 15.0 parts by weight, imidazole curing agent (manufactured by Shikoku Kasei, trade name: 2E4MZ-C
N) 1.6 parts by weight, a bifunctional acrylic monomer which is a photosensitive monomer (manufactured by Nippon Kayaku Co., Ltd., trade name: R604) 4.5
Parts by weight, also polyvalent acrylic monomer (Kyoei Chemical Co.,
Trade name: DPE6A) 1.5 parts by weight and dispersion defoaming agent (S-65, manufactured by San Nopco, S-65) 0.71 parts by weight are put in a container, stirred and mixed to prepare a mixed composition, and this mixed composition By adding 2.0 parts by weight of benzophenone (manufactured by Kanto Chemical Co., Inc.) as a photopolymerization initiator and 0.2 part by weight of Michler's ketone (manufactured by Kanto Chemical Co., Inc.) as a photosensitizer, the viscosity at 25 ° C. A solder resist composition adjusted to 2.0 Pa · s was obtained. The viscosity was measured with a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) in the case of 60 min ⁻¹ . Rotor N for 4, 6 min ^-1
o. According to 3.

(17) Next, the solder resist composition having a thickness of 20 μm is applied to both surfaces of the multilayer wiring board,
After performing a drying treatment under conditions of 70 ° C. for 20 minutes and 70 ° C. for 30 minutes, a photomask having a thickness of 5 mm on which a pattern of a solder resist opening portion is drawn is brought into close contact with the solder resist layer, and a photo resist of 1000 mJ / cm ² Exposed with UV light,
It was developed with a DMTG solution to form an opening having a diameter of 200 μm. And then, at 80 ℃ for 1 hour, 100 ℃
1 hour, 120 ° C. for 1 hour, and 150 ° C. for 3 hours to heat-treat the solder resist layer, thereby forming a solder resist pattern layer 14 having openings and a thickness of 20 μm. . As the solder resist composition, a commercially available solder resist composition can also be used.

(18) Next, the substrate on which the solder resist layer 14 is formed is treated with nickel chloride (2.3 × 10 ⁻¹ mol).
/ L), sodium hypophosphite (2.8 × 10 ⁻¹ mol
/ L), sodium citrate (1.6 × 10 ⁻¹ mol /
2) to the electroless nickel plating solution of pH = 4.5 containing 1)
After immersion for 0 minute, a nickel plating layer 15 having a thickness of 5 μm was formed in the opening. Furthermore, the substrate gold potassium cyanide ^{(7.6 × 10 -3 mol / l} ), ammonium chloride ^{(1.9 × 10 -1 mol / l} ), sodium citrate (1.2 × 10 ^-1 mol / l) and sodium hypophosphite (1.7 × 10 ⁻¹ mol / l) in an electroless gold plating solution at a temperature of 80 ° C. for 7.5 minutes. A gold plating layer 16 of 0.03 μm was formed.

(19) Then, a solder paste containing tin-lead is printed on the opening of the solder resist layer 14 on the surface of the substrate on which the IC chip is mounted, and the opening of the solder resist layer 14 on the other surface is opened. After printing a solder paste containing tin-antimony on the substrate, the solder bumps (solder bodies) 17 are formed by reflowing at 200 ° C., and a multilayer printed wiring board having the solder bumps 17 is manufactured (FIG. 5C). reference).

(Example 2) A. Preparation of resin film for interlayer resin insulation layer and preparation of resin filler Preparation of resin film for interlayer resin insulation layer and preparation of resin filler were carried out in the same manner as in Example 1.

B. Manufacture of multilayer printed wiring board (1) 0.8mm thick glass epoxy resin or BT
A copper clad laminate having 18 μm copper foil 32 laminated on both surfaces of an insulating substrate 30 made of (bismaleimide triazine) resin was used as a starting material (see FIG. 6A). First, this copper clad laminate was etched into a lower conductor circuit pattern shape to form lower conductor circuits 34 on both surfaces of the substrate (see FIG. 6B).

(2) Substrate 3 on which the lower conductor circuit 34 is formed
Washed with water, dried and then NaOH (10 g / l),
NaClO ₂ (40 g / l), Na ₃ PO ₄ (6 g /
blackening treatment using an aqueous solution containing 1) as a blackening bath (oxidizing bath),
And NaOH (10 g / l), NaBH ₄ (6 g / l
A reduction treatment using an aqueous solution containing 1) as a reduction bath was performed to form a roughened surface 34a on the surface of the lower conductor circuit 34 (FIG. 6).
(See (C)).

(3) Next, the resin film for the interlayer resin insulation layer prepared in the above A is laminated by vacuum pressure bonding at 0.5 MPa while being heated to a temperature of 50 to 150 ° C., and the resin film layer 50α is formed. Was formed (see FIG. 6D). Further, the substrate 30 having the resin film layer 50α attached thereto is drilled to form a through hole 35 having a diameter of 300 μm.
Was formed (see FIG. 6 (E)).

(4) Next, on the resin film layer 50α,
Through a mask in which a through hole having a thickness of 1.2 mm is formed,
CO ₂ gas laser with a wavelength of 10.4 μm, beam diameter 4.0 mm, top hat mode, pulse width 8.0 μ
Second, an opening 52 for a via hole having a diameter of 80 μm was formed in the resin film layer 50α under the condition of one shot of a mask through hole having a diameter of 1.0 mm to form an interlayer resin insulation layer 50 (see FIG. 7A). .

(5) The substrate having the via hole openings 52 formed therein is dipped in a solution containing 60 g / l of permanganic acid at 80 ° C. for 10 minutes to perform desmear treatment on the wall surface of the through hole 35 and to remove the interlayer resin. By dissolving and removing the epoxy resin particles existing on the surface of the insulating layer 50, the roughened surface 50a on the surface including the inner wall surface of the via hole opening 52,
52a was formed (see FIG. 7B).

(6) Next, the substrate after the above processing is
It was immersed in a Japanese solution (made by Shipley) and washed with water. It
In addition, the surface of the substrate that has been roughened (roughening depth 3 μm)
By adding a palladium catalyst to the
The surface of the edge layer 50 (including the inner wall surface of the via hole opening 52).
And the catalyst nuclei were attached to the wall surface of the through hole 35.
(Not shown). That is, the above substrate is palladium chloride
(PdCl₂ ) And stannous chloride (SnCl) ₂ ) And including
Immersion in the catalyst solution to deposit palladium metal
More catalyst was applied.

(7) Next, the substrate is immersed in an electroless copper plating solution having the following composition, and the surface of the interlayer resin insulation layer 50 (including the inner wall surface of the via hole opening 52) and:
An electroless copper plating film 42 having a thickness of 0.6 to 3.0 μm was formed on the wall surface of the through hole 35 (see FIG. 7C). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l Tartaric acid 0.200 mol / l Copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α′-bipyridyl 100 mg / l polyethylene glycol (PEG) 0.10 g / l [electroless plating conditions] 40 minutes at a liquid temperature of 34 ° C

(8) Next, a commercially available photosensitive dry film is attached to the substrate on which the electroless copper plating film 42 is formed,
Place a mask and expose at 100 mJ / cm ² ,
By developing with an 8% sodium carbonate aqueous solution,
A plating resist 43 having a thickness of 20 μm was provided (see FIG. 7).
(D)).

(9) Next, the substrate is washed with water at 50 ° C. to degrease it, washed with water at 25 ° C., and further washed with sulfuric acid, and then electrolytic plating is performed under the following conditions to remove the plating resist 43 An electrolytic copper plating film 44 having a thickness of 20 μm was formed in the formation portion (see FIG. 7E). [Electrolytic plating solution] Sulfuric acid 2.24 mol / l Copper sulfate 0.26 mol / l Additive 19.5 ml / l (Akatech Japan Co., Ltd., Kaparaside GL) [Electrolytic plating conditions] Current density 1 A / dm ² hours 65 minutes temperature 22 ± 2 ℃

(10) Further, the plating resist 43 is set to 5
After stripping off with% KOH, the electroless plating film under the plating resist 43 is etched by a mixed solution of sulfuric acid and hydrogen peroxide to dissolve and remove the through hole 36 and the upper conductor circuit (via hole 46). Is included) (see FIG. 8 (A)). Among the through holes 36 formed in this step, the through hole existing near the center of the substrate (interlayer resin insulation layer) has a distance of 650 μm from the adjacent through hole, and is located near the outer edge of the substrate (interlayer resin insulation layer). The existing through holes have a distance of 2.0 to 3.0 mm from the adjacent through holes. In all the through holes, the conductor layer has a thickness of 25 μm, and the diameter of the void existing in the center of the through hole is 300 μm.

(11) Next, the substrate 30 having the through holes 36 and the like formed therein is immersed in an etching solution to form the through holes 3
6 and upper layer conductor circuit (including via hole 46)
Roughened surfaces 36a and 46a were formed on the surface of (FIG. 8 (B)).
reference). As the etching solution, an etching solution (10% by weight of imidazole copper (II) complex, 7 parts by weight of glycolic acid, 5 parts by weight of potassium chloride (manufactured by MEC Co., Ltd.,
Mech etch bond) was used.

(12) Next, after the resin filler described in the above B is prepared, the through hole 36 and the via hole 46 on one side of the substrate 30 are prepared within 24 hours after the preparation by the following method. The resin filler 54 'was filled. That is, a resin filling mask having openings in portions corresponding to through holes and via holes is placed on the interlayer resin insulation layer on which the upper conductor circuit is formed, and a squeegee is used to insert the resin into the through holes and the recesses. Was filled with a resin filler and dried (semi-curing treatment) at 100 ° C. for 20 minutes. Further, in the same manner, the resin filling material 54 'was filled in the via hole on the other surface of the substrate and dried (semi-curing treatment) (see FIG. 8C).

The opening in the resin filling mask corresponding to the through hole existing in the vicinity of the center of the substrate (interlayer filling insulating layer) has a diameter of 300 μm. The diameter of the opening portion at the portion corresponding to the through hole existing in the vicinity of the outer edge of (4) is 400 μm (about 1.78 times the area of the through hole).

(13) Next, both sides of the substrate which has been subjected to the treatment of (12) above are subjected to buff polishing to flatten the surface of the resin filler exposed from the through holes 36 and the via holes 46. Then, heat curing was performed at 100 ° C. for 1 hour and at 150 ° C. for 1 hour to form a resin filler layer 54.

(14) Next, on the surface of the interlayer resin insulation layer 50 and the exposed surface of the resin filler layer 54, the above (6) is applied.
A palladium catalyst (not shown) was applied by carrying out the same treatment as described above. Further, electroless plating was performed under the same conditions as in (7) above to form an electroless plated film 56 on the surface of the interlayer resin insulation layer 50 and the exposed surface of the resin filler layer 54 (FIG. 9 (A). )reference).

(15) Next, a plating resist having a thickness of 20 μm was provided on the electroless plated film 56 by using the same method as the above (8) (not shown). Furthermore, the above (9)
Electrolytic plating was performed under the same conditions as above to form an electrolytic plated film 57 on the plating resist non-formed portion. After that, the plating resist and the electroless plating film 56 existing thereunder are removed, and the lid plating layer 58 including the electroless plating film 56 and the electrolytic plating film 57 is formed on the through hole 36 and the via hole 46. Formed (see FIG. 9B).

(16) Next, a roughened surface 58a was formed on the surface of the lid plating layer 58 by using the etching solution (Mec Etch Bond) used in the above (11) (see FIG. 9C).

(17) Next, by repeating the above steps (3) to (11), the upper interlayer resin insulation layer 60 and the conductor circuit (including the via hole 66) are formed,
A multilayer wiring board was obtained (see FIG. 9 (D)). No through holes were formed in this step.

(18) Next, a solder resist composition was obtained in the same manner as in Example 1, and the solder resist composition was applied to both surfaces of the multilayer wiring board to a thickness of 20 μm, and 70 The layer 7 of the solder resist composition is subjected to a drying treatment under conditions of 20 ° C. for 20 minutes and 70 ° C. for 30 minutes.
0α was formed (see FIG. 10A). Then, a 5 mm-thick photomask on which the pattern of the solder resist opening is drawn is brought into close contact with the solder resist layer to form 100
It was exposed to ultraviolet rays of 0 mJ / cm ² and developed with a DMTG solution to form openings 71 having a diameter of 200 μm. Then, at 80 ° C. for 1 hour, 100 ° C. for 1 hour, 12
The solder resist layer was cured by heat treatment under conditions of 0 ° C. for 1 hour and 150 ° C. for 3 hours to form a solder resist layer 70 having openings and a thickness of 20 μm (FIG. 10 (B )reference). A commercially available solder resist composition can also be used as the above-mentioned solder resist composition.

(19) Next, the solder resist layer 70 is formed.
The formed substrate is replaced with nickel chloride (2.3 × 10^-1mol
/ L), sodium hypophosphite (2.8 × 10^-1mol
/ L), sodium citrate (1.6 × 10^-1mol /
2) to the electroless nickel plating solution of pH = 4.5 containing 1)
Immerse for 0 minutes, and insert nickel in the opening 71 to a thickness of 5 μm.
A plating layer 72 was formed. In addition, the substrate is gold cyanide
Potassium (7.6 x 10 ^-3mol / l), ammonium chloride
Umm (1.9 × 10^-1mol / l), sodium citrate
Mu (1.2 x 10^-1mol / l), sodium hypophosphite
Mu (1.7 × 10 ^-1mol / l) containing electroless gold plating
Immerse the solution in the liquid at 80 ° C for 7.5 minutes and apply nickel plating.
A 0.03 μm thick gold plating layer 74 is formed on the plating layer 72.
(See FIG. 10 (C)).

(20) After that, tin-plated in the opening 71 of the solder resist layer 70 on the surface of the substrate on which the IC chip is mounted.
By printing a solder paste containing lead and forming a solder bump (solder body) 76 by reflowing at 200 ° C., after printing the solder paste on the other surface, by attaching a conductive connection pin 78 , A multilayer printed wiring board was manufactured (see FIG. 11).

Example 3 A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that the following resin filling mask was used in the step (3) of Example 1. The resin filling mask has a diameter of an opening portion of 300 μm at a portion corresponding to a through hole existing near the outer edge of the substrate and a through hole having a diameter of 150 μm (0.25 times the area of the opening portion) around the opening. Have The distance between the through hole and the opening is 0.2 mm. In addition, the diameter of the opening in the portion corresponding to the through hole existing near the center of the substrate is 300 μm.

Example 4 A multilayer printed wiring board was manufactured in the same manner as in Example 2 except that the following resin filling mask was used in the step (12) of Example 2. The resin filling mask has a diameter of an opening of 300 μm in a portion corresponding to a through hole existing near the outer edge of the substrate.
And a through hole having a diameter of 200 μm (0.44 times the area of the opening) is provided around it. The distance between the through hole and the opening is 0.3 mm. In addition, the diameter of the opening in the portion corresponding to the through hole existing near the center of the substrate is 300 μm.

Comparative Example 1 A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that the following resin filling mask was used in the step (3) of Example 1. As the resin-filling mask, the opening in the portion corresponding to the through hole near the center of the substrate and the opening in the portion corresponding to the through hole near the outer edge of the substrate have a diameter of 300 μm. Was used. The polishing of the resin filler was carried out until there was no raised portion.

Comparative Example 2 A multilayer printed wiring board was manufactured in the same manner as in Example 2 except that the resin filling mask described below was used in the step (12) of Example 2. As the resin-filling mask, the opening in the portion corresponding to the through hole near the center of the substrate and the opening in the portion corresponding to the through hole near the outer edge of the substrate have a diameter of 300 μm. Was used. The polishing of the resin filler was carried out until there was no raised portion.

Obtained in Examples 1 to 4 and Comparative Examples 1 and 2.
Through-holes for multi-layer printed wiring boards
Cut at the part that contains, and observe the cross-sectional shape with a microscope.
It was In addition, a heat cycle test was conducted by the following method.
After that, cut the multilayer printed wiring board and
The surface was observed under a microscope. Also, Examples 1 to 4 and comparison
Another multi-layer printed wiring board obtained by the method of Examples 1 and 2 has an IC chip.
Of the continuity test before and after the heat cycle test.
Test was carried out.Heat cycle test Cycling at 130 ° C for 3 minutes and -65 ° C for 3 minutes
1000 cycles.

As a result, in the multilayer printed wiring boards obtained in Examples 1 to 4, the through holes were completely filled with the resin filler, and the interlayer resin insulation layer formed thereon had undulations or depressions. Did not occur. The continuity was good before and after the heat cycle test. further,
In the multilayer printed wiring boards of Examples 2 and 4, the adhesion between the resin filler and the lid plating layer was good before and after the heat cycle test.

On the other hand, in the multilayer printed wiring board obtained in Comparative Example 1, the resin filler in the through hole formed in the vicinity of the center of the substrate has a concave surface layer portion. In some cases, the interlayer resin insulation layer formed thereon had undulations or depressions. Further, in the continuity test after the heat cycle test, there were some in which continuity failure occurred.

Further, even in the multilayer printed wiring board obtained in Comparative Example 2, the resin filler in the through hole formed near the center of the substrate was found to have a concave surface layer portion, Some of the lid plating layers formed thereon had depressions, and due to these depressions, there were portions where undulations and depressions were produced in the interlayer resin insulation layer. In addition, in the continuity test after the heat cycle test,
Some of them had poor continuity. Further, when the cross section of the multilayer printed wiring board was observed after the heat cycle test, there was a portion where peeling occurred between the resin filler and the lid plating layer.

[0127]

As described above, since the resin-filling masks of the first and second aspects of the present invention have the above-described structure, they can be used as through-holes when used in manufacturing a multilayer printed wiring board. The resin filler can be completely filled. Therefore, by manufacturing a multilayer printed wiring board using this resin filling mask, it is possible to reliably manufacture a multilayer printed wiring board having excellent connection reliability.

[Brief description of drawings]

1 (a) to 1 (d) are cross-sectional views showing a part of a manufacturing process of a multilayer printed wiring board using the resin filling mask of the present invention.

2 (a) to 2 (d) are cross-sectional views showing a part of manufacturing process of a multilayer printed wiring board using the resin filling mask of the present invention.

3 (a) to 3 (d) are cross-sectional views showing a part of a manufacturing process of a multilayer printed wiring board using the resin filling mask of the present invention.

4 (a) to 4 (c) are cross-sectional views showing a part of manufacturing process of a multilayer printed wiring board using the resin filling mask of the present invention.

5 (a) to 5 (c) are cross-sectional views showing a part of a manufacturing process of a multilayer printed wiring board using the resin filling mask of the present invention.

6 (A) to 6 (E) are cross-sectional views showing a part of a manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

7 (A) to 7 (E) are cross-sectional views showing a part of a manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

8A to 8D are cross-sectional views showing a part of a manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

9A to 9D are cross-sectional views showing a part of a manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

10A to 10C are cross-sectional views showing a part of the manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

FIG. 11 is a cross-sectional view showing a part of the manufacturing process of another multilayer printed wiring board using the resin filling mask of the present invention.

[Explanation of symbols]

1 substrate 2 interlayer resin insulation layer 3 plating resist 4 Lower layer conductor circuit 4a, 9a roughened surface 5 Upper layer conductor circuit 7 Via hole openings 8 copper foil 9 through holes 10 Resin filler 12 Electroless copper plating layer 13 Electrolytic plating layer 14 Solder resist layer 15 Nickel plating layer 16 Gold plating layer 17 Solder bump

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Claims (6)

[Claims] 1. A resin filling mask used for filling a resin filling material into a through hole formed in the manufacture of a multilayer printed wiring board, wherein the resin filling mask corresponds to the through hole. An opening is formed in the opening, and the opening formed in a portion of the opening corresponding to a through hole having a distance of 2.0 mm or more between adjacent through holes has an area equal to that of the through hole. A mask for resin filling, which is 1.5 to 2.5 times. 2. A resin filling mask used to fill a resin filling material into a through hole formed in the manufacture of a multilayer printed wiring board, wherein the resin filling mask corresponds to the through hole. An opening is formed in the opening, and the opening formed in a portion of the opening corresponding to a through hole having a distance between adjacent through holes of 2.0 mm or more has the area around the opening. A resin-filling mask having at least one through hole that is 0.1 times or more and less than 1.0 times the area of the part. 3. The resin filling mask according to claim 1, wherein the through hole is a through hole formed for connecting lower layer conductor circuits sandwiching the substrate. 4. The resin filling mask according to claim 3, wherein an opening is also provided in a portion corresponding to the lower conductor circuit non-forming portion on the substrate. 5. The resin filling mask according to claim 1, wherein the through hole is a through hole formed to connect at least the upper conductor circuit sandwiching the substrate and the interlayer resin insulation layer. 6. The opening according to claim 5, wherein the portion corresponding to the upper conductor circuit non-forming portion on the interlayer resin insulating layer and / or the portion corresponding to the via hole formed in the interlayer resin insulating layer also has an opening. Resin filling mask.