JP2015070169A - Wiring board and method of manufacturing wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board excellent in the internal heat dissipation, and reducing the constraints of wiring pattern design by thermal vias.SOLUTION: In a wiring board, a heat conduction path is formed in a core base material, by filling a through hole formed in the core base material with insulating resin for heat dissipation having a high thermal conductivity. Consequently, the heat in the wiring board can propagate efficiently to the outside of the wiring board. Furthermore, since the heat conduction path is formed of an insulating material, the wiring pattern can be arranged in a part where the insulating resin for heat dissipation exists, and the constraints of wiring pattern can be reduced.

Description

  The present invention relates to a wiring board and a wiring board manufacturing method suitable for manufacturing the wiring board.

  In order to electrically connect the semiconductor chip to the mother board, a wiring board is arranged between the semiconductor chip and the mother board. By arranging the wiring board, it is possible to bridge the difference in thermal expansion coefficient between the semiconductor chip and the mother board, and to improve the bonding reliability. Such a wiring substrate is called a semiconductor package substrate, an interposer substrate, or the like.

  Here, the wiring board is required to efficiently release heat generated from the semiconductor chip or the like from the viewpoint of preventing malfunction of the device due to thermal runaway of the semiconductor chip. For this reason, various heat dissipation measures have been proposed.

  For example, it has been proposed to stack a highly heat-conductive substance (ceramic) on the upper and lower surfaces of a wiring board (see Patent Document 1).

  Further, when a material having high heat conductivity is laminated on the outer periphery of the wiring board, the heat dissipation of the outer periphery of the wiring board is improved, but the heat dissipation inside the wiring board is not improved. For this reason, it has been proposed to provide a heat transfer path for heat dissipation inside the wiring board.

  For example, it has been proposed to fill a through hole with a copper paste so that the through hole electrode functions as a heat transfer path (thermal via) for heat dissipation (see Patent Document 2).

JP 2009-004709 A JP 2004-134378 A

  When a conductive metal such as copper with high thermal conductivity is used for the thermal via, the layout position of the thermal via that is optimal for heat dissipation and the optimal wiring pattern for wiring use compete spatially. However, there is a problem that is restricted by designing avoiding thermal vias.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wiring board that is excellent in heat dissipation inside the wiring board and that reduces restrictions on wiring pattern design due to thermal vias.

[1] An embodiment of the present invention includes a core base material, a pattern wiring layer formed on the core base material, and a build-up layer laminated so as to cover the pattern wiring layer, The core base material is a core base material having at least one or more through holes, and at least one or more of the through holes are filled with an insulating resin for heat dissipation having a higher thermal conductivity than the core base material. The wiring board is characterized by this.
[2] The through-hole is a through-hole having a recess that forms a step with the surface of the core substrate, and at least the recess may be filled with an insulating resin for heat dissipation.
[3] The core substrate may be a glass substrate.
[4] One embodiment of the present invention includes at least one of a recess forming step for forming a recess in a core substrate, a through hole forming step for forming a through hole in a region where the recess is formed, and the through hole. A filling step of filling the heat insulating insulating resin having a higher thermal conductivity than the core base material, and a build-up step of laminating a pattern wiring layer and a build-up layer on the core base material. It is the wiring board manufacturing method characterized.

  The wiring board of the present invention creates a heat conduction path inside the core base material by filling through-holes formed in the core base material with a heat-dissipating insulating resin having a high thermal conductivity. Thereby, the heat inside the wiring board can be efficiently propagated to the outside of the wiring board. In addition, since the heat conduction path is formed of an insulating material, the wiring pattern can be disposed at a portion where the heat-insulating insulating resin exists, and the restriction on the wiring pattern can be reduced.

It is a schematic sectional drawing which concerns on an example of the wiring board of this invention. It is a schematic sectional drawing which concerns on an example of the wiring board of this invention. It is a schematic process drawing concerning an example of a wiring board manufacturing method of the present invention. It is a schematic process drawing concerning an example of a wiring board manufacturing method of the present invention. It is a schematic sectional drawing which concerns on the wiring board of a comparative example.

(Core substrate)
The core base material is a part that becomes a base of the wiring board. The core substrate has at least one or more through holes.

  As the core substrate, an organic material substrate, a silicon substrate, a glass substrate, or the like can be used. In particular, a silicon substrate and a glass substrate are preferable because the linear expansion coefficient (CTE) is the same as or close to that of a semiconductor chip, so that stress generated by a difference in thermal expansion coefficient can be reduced during mounting. In addition, a wiring board using a silicon substrate or a glass substrate as a core base material is expected to be used for 2.5D mounting, 3D mounting, and the like.

  The core substrate is particularly preferably a glass substrate. The thermal conductivity of silicon is about 168 W / m · K, and the thermal conductivity of glass is about 1 W / m · K, which is a difference of 100 times or more. That is, the glass substrate is less likely to escape heat than the silicon substrate, and if the structure is the same, the wiring substrate using the glass substrate tends to have lower heat dissipation. For this reason, the glass substrate tends to accumulate heat inside, and there is a great need to improve heat dissipation. According to the wiring board of the present invention, heat inside the wiring board can be efficiently propagated to the outside of the wiring board, so that problems specific to the glass substrate can be effectively solved. Here, as the glass substrate, specifically, for example, non-alkali glass, synthetic quartz glass, or the like may be used. Moreover, when using a glass substrate, it is preferable that the thickness of a glass substrate exists in the range of about 100 micrometers or more and 500 micrometers or less. However, the thickness of the glass substrate used in the wiring board of the present invention is not limited to the above range.

  Further, the outer shape of the core substrate is not particularly limited, and may be appropriately determined according to the desired use. For example, it may be an outer shape such as a plate shape, a square shape, or a circular shape.

(Through hole)
A through hole is a hole which penetrates the front and back of a core base material. By filling the through holes with a conductive material, the upper and lower surfaces of the core substrate can be electrically connected (through hole electrodes). Further, in the wiring board of the present invention, the through hole is filled with a heat radiation insulating resin having a higher thermal conductivity than the core base material. As a result, a heat conduction path penetrating the front and back of the core base material can be formed, and heat inside the wiring board can be propagated to the outside.

  Further, the arrangement location, range, dimensions, shape, quantity, etc. of the through holes are not particularly limited, and may be determined based on the design of the wiring pattern. Specifically, for example, a circular hole shape with an opening diameter of about 10 μm to 500 μm may be used.

  The through hole may be a through hole having a recess that forms a step with the core substrate surface. By filling the recess with the insulating resin for heat dissipation, the surface area where the core substrate and the insulating resin for heat dissipation come into contact can be increased. For this reason, heat can be suitably propagated from the core base material to the insulating resin for heat dissipation, and the heat dissipation characteristics are improved.

(Insulating resin for heat dissipation)
The heat radiating insulating resin is filled in at least one of the through holes formed in the core base material. By filling the through-hole with insulating resin for heat dissipation with high thermal conductivity, it is possible to create a heat conduction path inside the core base material and efficiently propagate the heat inside the wiring board to the outside of the wiring board. it can. In addition, since the heat conduction path is formed of an insulating material, the wiring pattern can be disposed at a portion where the heat-insulating insulating resin exists, and the restriction on the wiring pattern can be reduced.

  As the insulating resin for heat dissipation, an insulating resin having a thermal conductivity larger than that of the selected core substrate and having good adhesion to the selected core substrate may be appropriately selected and used. For example, when a glass substrate is used for the core base material, an epoxy resin containing a heat conductive filler, a ceramic resin, or the like may be used.

  Further, an adhesive layer may be formed between the heat radiation insulating resin and the core base material. By forming the adhesive layer, the adhesion between the insulating resin for heat dissipation and the core base material is improved, and even a resin with poor adhesion to the core base material can be selected as the insulating resin for heat dissipation. The material for the adhesion layer may be any material having an insulating property. In the case of forming the adhesion layer, the film thickness of the adhesion layer may be in the range of about 1 nm to 9 nm. However, the film thickness of the adhesion layer is not limited to the above range.

(Build-up layer / Pattern wiring layer)
The pattern wiring layer is formed on both surfaces of the core substrate. The buildup layer is laminated so as to cover the pattern wiring layer. Furthermore, a multilayer wiring board can be manufactured by alternately laminating pattern wiring layers and build-up layers (build-up method). Here, the stacked build-up layer is processed by forming a hole (via hole), filled with a conductive material, and electrically connected to the upper and lower pattern wiring layers of the build-up layer (via electrode).

  The material of the pattern wiring layer is formed using a conductive material. For example, copper may be used.

  The material for the buildup layer may be appropriately selected from insulating materials used in known buildup methods. For example, an epoxy resin, a polyimide resin, or the like may be used.

  In the via hole formed in the build-up layer, the shape / dimension may be appropriately determined according to the design of the wiring pattern. Specifically, for example, it may be a hole having an opening diameter in the range of about 20 μm to 100 μm.

  In the wiring board of the present invention, an electrode pad may be formed on the outermost surface in order to connect an electric signal to the outside. When the electrode pad is formed, a solder resist may be laminated on the outermost surface so as to open on the electrode pad. Here, as the solder resist, for example, a photosensitive epoxy resin, a resin to which a filler is added, and the like can be used.

FIG. 1 shows an example of a wiring board of the present invention in which a through hole having a recess is formed.
The wiring board of the present invention shown in FIG. 1 includes a core substrate 1 in which through holes having recesses are formed, an insulating resin 2 for heat dissipation filled in the through holes having recesses, and electrical surfaces on the front and back of the core substrate 1. A through-hole electrode 3 to be connected, a pattern wiring layer 4 laminated on the core substrate 1 and the build-up layer 5, a build-up layer 5 provided to insulate the pattern wiring layer 4 of each layer, and the build-up layer 5 The structure includes a via electrode 6 that electrically connects the pattern wiring layer 4 up and down, a solder resist 8 provided on the uppermost buildup layer 5, and an electrode pad 7 provided in an opening of the solder resist 8. In FIG. 1, a part of the pattern wiring layer 4 disposed on the core substrate 1 is disposed on the filling surface of the heat-dissipating insulating resin 2 filled in the through-holes having the recesses, thereby restricting the wiring pattern. It has been shown that it can be mitigated.

  In the wiring board of the present invention, when a through hole having a concave portion is formed, it is sufficient that at least the concave portion is filled with an insulating resin for heat dissipation, and a plurality of materials may be filled in the through hole. If the insulating resin for heat dissipation is provided at least in the recesses, the surface of the core substrate can be insulated, so that the pattern wiring layer formed on the surface of the core substrate can be freely designed. At this time, since the material filled in the through hole does not necessarily need to be an insulating material, a material having high thermal conductivity can be freely selected. For example, a metal material such as copper may be used as a material for filling the through hole.

FIG. 2 shows an example of the wiring board of the present invention in which a through hole having a concave portion is formed and only the concave portion is filled with an insulating resin for heat dissipation.
The wiring board of the present invention shown in FIG. 2 includes a core base material 1 in which through holes having recesses are formed, an insulating resin 2 for heat dissipation filled in the recesses of the through holes having recesses, and the through holes having recesses. Filled high thermal conductive material 9, through-hole electrode 3 for electrical connection between the front and back of core substrate 1, pattern wiring layer 4 laminated on core substrate 1 and buildup layer 5, pattern wiring layer 4 of each layer Build-up layer 5 provided so as to insulate, via electrode 6 electrically connecting pattern wiring layer 4 above and below build-up layer 5, solder resist 8 provided on uppermost build-up layer 5, solder resist 8 is provided with electrode pads 7 provided in the openings. In FIG. 2, the through hole having a recess formed in the core substrate 1 is filled with a heat-dissipating insulating resin 2 and the high thermal conductive material 9 inside, and the through hole is filled with a plurality of materials. Is shown. In the wiring board of the present invention shown in FIG. 2, the high thermal conductivity material 9 does not necessarily need to be an insulating material, and may be a metal material such as copper having a high thermal conductivity.

  Hereinafter, an example of the wiring board manufacturing method of the present invention will be described. In addition, the wiring board of this invention is not limited to the wiring board manufactured with the following wiring board manufacturing methods.

(Recess formation process)
First, a recess is formed in the core substrate.

  In forming the recesses, a material selected for the core base material, the shape / dimensions of the recesses, and the like may be taken into consideration and selected from known fine processing methods. The depth of the recess is appropriately determined in consideration of the rigidity of the core substrate. For example, (1) ablation with a laser device, (2) chemical etching, (3) fine cutting, or the like may be used. Here, when a glass substrate is selected as the core base material, hydrofluoric acid can be used for chemical etching.

(Through hole forming process)
Next, a through hole is formed in the region where the recess is formed. At this time, a through hole for a through hole electrode may be formed at the same time.

  For forming the through hole, a known hole processing method may be appropriately selected and used. For example, laser processing (specifically, UV laser, carbon dioxide laser, excimer laser, etc.), drill processing, or the like may be used.

(Filling process)
Next, the through holes are filled with insulating resin for heat dissipation.

  The filling method of the insulating resin for heat dissipation may be appropriately selected from known filling methods according to the selected insulating resin for heat dissipation, the shape and dimensions of the through hole, and the like. For example, (1) a printing method, (2) a method of laminating a film-like insulating resin for heat dissipation and reducing the pressure may be performed. In addition, when filling the insulating resin for heat dissipation, it may be filled one side or both sides of the core substrate at a time.

  In addition, when a plurality of materials are filled in the through hole having the recess, the filling methods may be appropriately combined depending on the material to be filled. For example, when filling the through hole with copper / recessed insulating resin for heat dissipation, (1) an electroless plating film is formed on the surface of the core substrate by electroless plating, and (2) the through hole is formed by electrolytic plating. An electrolytic plating film may be formed inside, (3) etching the electroless plating film and the electrolytic plating film formed at the concave portion, and (4) filling the concave portion with an insulating resin for heat dissipation. .

  Further, the surface polishing may be performed after filling the through hole with the insulating resin for heat dissipation. By performing the surface polishing, the surface positions of the core base material surface and the filling portion of the insulating resin for heat radiation can be aligned, and the pattern wiring layer can be suitably laminated. As the surface polishing, for example, chemical polishing, sandblasting method, or the like may be used.

(Build-up process)
Next, a pattern wiring layer / build-up layer is laminated on the core substrate.

  First, a through-hole electrode and a pattern wiring layer are formed on the core substrate. Specifically, for the formation of the through-hole electrode and the pattern wiring layer, for example, (1) an electroless copper plating film is applied to the surface of the core substrate, the side surface of the through-hole, and the surface filled with the insulating resin for heat dissipation by electroless plating (2) A photoresist is formed on the electroless copper plating film, exposed and developed, and a resist pattern is formed. (3) Electrolytic copper is applied to the mask opening of the resist pattern by electrolytic plating. A plating film may be formed, (4) the resist pattern is peeled and removed, and (5) the electroless copper plating film exposed by the peeling of the resist pattern is removed by etching. Further, the copper plating forming method in the through hole is not limited to filled plating, and conformal plating may be performed. When conformal plating is performed, after conformal plating, a through hole electrode can be formed by inserting a resin into the through hole.

  Next, a buildup layer is formed on the pattern wiring layer. For the build-up layer formation, (1) the surface of the core substrate on which the pattern wiring layer is formed is roughened, (2) the insulating resin is laminated using a vacuum laminator, and (3) the insulating resin is cured. , You may go. At this time, lamination may be performed on both surfaces of the core base material on which the pattern wiring layer is formed.

  Next, a via is formed in the buildup layer. For forming the via, a hole processing method may be selected and used. For example, laser processing (specifically, UV laser, carbon dioxide laser, excimer laser, etc.) may be used. Further, when a photosensitive resin is selected as the insulating material used for the build-up layer, vias may be formed using a photolithography method.

  Next, desmear processing is performed. The desmear treatment is a step of removing smear (resin residue) generated in the via processing step. In particular, since laser processing generates smear, it is preferable to dissolve and remove smear by chemical treatment.

  Next, a via electrode and a pattern wiring layer are formed on the buildup layer. Specifically, the formation of the via electrode and the pattern wiring layer is, for example, (1) forming an electroless copper plating film on the entire surface of the buildup layer and the via side surface by electroless plating, and (2) electroless. A photoresist is formed on the copper plating film, exposed, developed, and a resist pattern is formed. (3) An electrolytic copper plating film is formed in the mask opening of the resist pattern by electrolytic plating, and (4 The resist pattern may be stripped and removed, and (5) the electroless copper plating film exposed by the stripping of the resist pattern may be removed by etching. Further, the copper plating forming method in the via is not limited to filled plating, and conformal plating may be performed, and a via electrode may be formed by inserting a resin into the through hole.

  In the build-up process, stacking may be repeated alternately with a pattern wiring layer / build-up as one set according to a desired wiring pattern. Thereby, a more multilayer wiring board can be manufactured. (Build-up method). Here, further formation of the pattern wiring layer / buildup layer may be performed in the same manner as described above.

(Formation of electrode pad / solder resist)
Next, an electrode pad / solder resist is formed on the uppermost layer of the buildup layer. Specifically, for example, (1) an electrode pad is formed on the top surface of the buildup layer, (2) a solder resist is laminated on the surface of the buildup layer including the electrode pad, and (3) the solder resist is exposed. The electrode pad may be exposed by developing and forming an opening. Further, for example, solder bumps and gold bumps may be formed as necessary for connection to the outside.

<Example 1>
Hereinafter, an example of the method for manufacturing a wiring board according to the present invention will be specifically described with reference to FIGS.

First, the core base material 1 was prepared (FIG. 3A).
The core substrate 1 was made of alkali-free glass of 27 mm × 27 mm and 500 μmt.

Next, the recessed part 10 was formed in the core base material 1 (FIG.3 (b)).
The concave portion 10 was formed by ablation using an excimer laser. Moreover, the dimension of the recessed part 10 was 2 mm x 2 mm and 50 micrometers. A plurality of recesses 10 were formed at predetermined locations.

Next, a through hole was formed in the core substrate 1, and a through hole 11 having a recess and an electrode through hole 12 were formed (FIG. 3C).
A maxima laser was used to form the through hole. The dimensions of the through holes were 50 μm opening diameter and 200 μm pitch.

Next, the heat-insulating insulating resin 2 was filled in the through-hole 11 having a recess (FIG. 3D).
The insulating resin 2 for heat radiation was a liquid resin obtained by adding a thermally conductive filler to an epoxy resin of 10 W / m · K. Moreover, the printing method was used for application filling of the insulating resin 2 for heat radiation.

  Next, the filled insulating resin 2 for heat radiation was cured, and the surface positions of the surface of the core base material 1 and the insulating resin 2 for heat radiation filled in the recess 10 were aligned by surface polishing. Here, the effect condition of the insulating resin 2 for heat radiation was 180 ° C. for 1 hour. Further, a sand blasting device was used for the surface polishing.

Next, the through-hole electrode 3 was formed in the pattern wiring layer 4 and the electrode through-hole 12 on the surface of the core substrate 1 (FIG. 3E).
The through-hole electrode 3 and the pattern wiring layer 4 are (1) electroless copper plated on the surface of the core substrate 1 (including the surface filled with the insulating resin 2 for heat dissipation) and the side surface of the electrode through-hole 12 by electroless plating. A film is formed, (2) a photoresist is formed on the formed electroless copper plating film, exposed and developed to form a resist pattern, and (2) an opening of the resist pattern is formed. Then, an electrolytic copper plating film is formed by electrolytic plating, (3) the resist pattern is peeled and removed, and (4) the electroless copper plating film exposed by peeling the resist pattern is removed by etching. did. Here, the film thickness of the photoresist was about 30 μmt. The thickness of the electrolytic copper plating film formed by the electrolytic plating method was about 17 μm. The pattern wiring layer 4 was formed of two layers in which an electrolytic copper plating film was laminated on an electroless copper plating film.

Next, a first buildup layer 5 was formed so as to cover the first pattern wiring layer 4.
The build-up layer 5 includes (1) roughening the surface of the core substrate 1 on which the pattern wiring layer 4 is formed, (2) laminating an insulating material using a vacuum laminator device, and (3) the insulating material Cured and formed. Here, the build-up layer 5 has a thickness of 50 μmt. Further, an epoxy insulating resin was used as the insulating material. The lamination conditions were 100 ° C. and a load of 10 kg / cm 2. The curing conditions for the insulating material were 100 ° C., 30 minutes, 170 ° C., and 30 minutes.

Next, a via hole was formed in the first buildup layer 5.
A UV laser device was used to form the via hole. The opening diameter of the via hole was 50 μm. In addition, desmear treatment was performed on smears of via holes generated during laser processing.

Next, a second pattern wiring layer 4 was formed on the surface of the first buildup layer 5, and a via electrode 6 was formed in the via hole (FIG. 4A).
The via electrode 6 and the pattern wiring layer 4 are formed by (1) forming an electroless copper plating film on the surface of the buildup layer 5 and the side surface of the via hole by electroless plating, and (2) on the formed electroless copper plating film (2) An electrolytic copper plating film is formed by electrolytic plating at the opening of the resist pattern, and (3) a photoresist pattern is formed, exposed and developed. The resist pattern was removed by stripping, and (4) the electroless copper plating film exposed by the stripping of the resist pattern was removed by etching. Here, the film thickness of the photoresist was about 30 μmt. The thickness of the electrolytic copper plating film formed by the electrolytic plating method was about 17 μm. The pattern wiring layer 4 was formed of two layers in which an electrolytic copper plating film was laminated on an electroless copper plating film.

Next, a second buildup layer 5 was formed so as to cover the second pattern wiring layer 4.
The build-up layer 5 is (1) roughening the build-up layer 5 on which the pattern wiring layer 4 is formed, (2) laminating an insulating material using a vacuum laminator, and (3) curing the insulating material. And formed. Here, the build-up layer 5 has a thickness of 50 μmt. Further, an epoxy insulating resin was used as the insulating material. The lamination conditions were 100 ° C. and a load of 10 kg / cm 2. The curing conditions for the insulating material were 100 ° C., 30 minutes, 170 ° C., and 30 minutes.

Next, via holes were formed in the second buildup layer 5.
A UV laser device was used to form the via hole. The opening diameter of the via hole was 50. In addition, desmear treatment was performed on smears of via holes generated during laser processing.

Next, the electrode pad 7 and the via electrode 6 were formed in the via hole on the surface of the second buildup layer 5 (FIG. 4B).
The via electrode 6 and the electrode pad 7 are formed by (1) forming an electroless copper plating film on the surface of the buildup layer 5 and the side surface of the via hole by an electroless plating method, and (2) on the formed electroless copper plating film. A photoresist film is formed, exposed and developed to form a resist pattern; (2) an electrolytic copper plating film is formed in the opening of the resist pattern by electrolytic plating; The resist pattern was peeled and removed, and (4) the electroless copper plating film exposed by peeling of the resist pattern was removed by etching. Here, the film thickness of the photoresist was about 30 μmt. The thickness of the electrolytic copper plating film formed by the electrolytic plating method was about 17 μm. The electrode pad 7 was formed of two layers in which an electrolytic copper plating film was laminated on an electroless copper plating film.

  Next, a photosensitive solder resist 8 was laminated on the uppermost layer of the buildup layer 5 by a vacuum laminating apparatus, exposed and developed, and the solder resist on the electrode pad 7 was removed (FIG. 4C).

  From the above, the wiring board of the present invention having a three-layer structure shown in FIG. 1 was manufactured.

<Comparative Example 1>
A wiring board was manufactured in the same manner as in Example 1. However, a through hole having a recess was not formed in the core base material.

FIG. 5 shows a wiring board manufactured in Comparative Example 1.
The wiring substrate of Comparative Example 1 shown in FIG. 5 includes a core base material 1 in which through holes are formed, a through-hole electrode 3 that electrically connects the front and back of the core base material 1, the core base material 1 and the buildup layer 5 Pattern wiring layer 4 stacked on each other, build-up layer 5 provided so as to insulate pattern wiring layer 4 of each layer, via electrode 6 electrically connecting pattern wiring layer 4 above and below build-up layer 5, uppermost layer The solder resist 8 provided on the buildup layer 5 and the electrode pad 7 provided in the opening of the solder resist 8 are provided.

<Measurement / Evaluation>
The thermal conductivity of the wiring boards manufactured in Example 1 and Comparative Example 1 was measured. The thermal conductivity was calculated from the amount of heat and the temperature difference in which one side of the wiring substrate was heated and the other side was cooled using a temperature gradient method, and the temperature gradient was provided on each surface. The results are shown below.
Example 1: 0.76 W / m · K
Comparative Example 1: 0.61 W / m · K

  When the thermal conductivity was compared between Example 1 and Comparative Example 1, it was shown that Example 1 had a larger value and heat was efficiently propagated. Therefore, it was confirmed that by adopting the structure of the wiring board of the present invention, the thermal conductivity of the wiring board was increased and the heat dissipation of the wiring board was improved.

DESCRIPTION OF SYMBOLS 1 ... Core base material 2 ... Insulating resin 3 for thermal radiation ... Through-hole electrode 4 ... Pattern wiring layer 5 ... Build-up layer 6 ... Via electrode 7 ... Electrode pad 8 ... Solder resist 9 ... High heat Conductive material 10 ... recess 11 ... through hole 12 having a recess 12 through hole for electrode

Claims (4)

A core substrate;
A pattern wiring layer formed on the core substrate;
A build-up layer laminated so as to cover the pattern wiring layer,
The core substrate is a core substrate having at least one or more through holes,
A wiring board, wherein at least one of the through holes is filled with an insulating resin for heat radiation having a higher thermal conductivity than the core base material. The through hole is a through hole having a recess that forms a step with the core substrate surface,
The wiring board according to claim 1, wherein at least the recess is filled with an insulating resin for heat dissipation. The wiring substrate according to claim 1, wherein the core base material is a glass base material. A recess forming step of forming a recess in the core substrate;
A through hole forming step of forming a through hole in a region where the concave portion is formed;
A filling step of filling at least one or more of the through holes with an insulating resin for heat dissipation having a higher thermal conductivity than the core substrate;
A build-up step of laminating a pattern wiring layer and a build-up layer on the core substrate;
A method for manufacturing a wiring board, comprising: