JP2017034193A - Wiring board and manufacturing method therefor, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable wiring board by, by taking account of thermal expansion of an insulation material filling a first through-hole in a first insulation part and the thermal expansion of a second insulation part, reducing stress load on a third conductive part resulting mainly from the thermal expansion of the latter together with stress load on a second conductive part resulting mainly from the thermal expansion of the former, thereby preventing fracture in both as much as possible, and to provide a manufacturing method for the wiring board, and to provide an electronic apparatus.SOLUTION: A wiring board comprises: a core substrate 11 having a through-hole 11a; a conductive film 21 formed on the internal wall of the through-hole 11a; resin 22 filling the through-hole 11a via the conductive film 21; an insulation film 23 formed on the core substrate 11; a land 24 formed in the insulation film 23, electrically connected with the conductive film 21, and having a through-hole 24a on the resin 22; and a veer 26 electrically connected with the land 24 within the insulation film 23.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiring board, a manufacturing method thereof, and an electronic device.

  As a wiring substrate, for example, as shown in FIG. 10, there is an insulating layer or an insulating part such as a substrate, for example, one having a through electrode 102 that penetrates a core substrate 101. The through electrode 102 is formed by covering the inner wall of the through hole 101 a formed in the core substrate 101 with the conductive film 111 and filling the through hole 101 a with the resin 112 through the conductive film 111. In the wiring board, build-up layers 103 are respectively laminated on the upper surface and the lower surface of the core substrate 101, and in the insulating film 113 of each build-up layer 103, there are lands 114 that are conductors connected to the conductive film 111, and thereabove. Land 115, and via 116 connecting land 114 and land 115 are formed.

JP 2000-49458 A JP 2003-218529 A JP2015-126053A

  In the wiring board having the through electrode 102 as shown in FIG. 10, there is a difference in thermal expansion coefficient between the materials used, that is, the insulating material, the conductive material, and the resin material. The resin 112 is relatively large in thermal expansion and contracts by subsequent cooling. Therefore, when the land 114 is formed on the conductive film 111 and the resin 112 of the core substrate 101, stress is applied to the land 114 due to the expansion and contraction of the resin 112 in the through hole 101a as shown in FIG. There is a concern that the land 114 may break.

  The present invention considers the thermal expansion of the insulating material embedded in the first through hole of the first insulating portion and the thermal expansion of the second insulating portion, and mainly stress load of the second conductive portion due to the former thermal expansion. In addition, a highly reliable wiring board, a method of manufacturing the same, and an electronic device are provided by reducing the stress load on the third conductive portion mainly caused by the latter thermal expansion and preventing the breakage of both as much as possible. For the purpose.

  As one aspect, the wiring board includes a first insulating part having a first through hole, a first conductive part formed on an inner wall of the first through hole, and the first through part as the first conductive part. An insulating material embedded therein, a second insulating portion formed on the first insulating portion, a second insulating portion formed in the second insulating portion and connected to the first conductive portion, and a second on the insulating material A second conductive part having a through hole; and a third conductive part connected to the second conductive part in the second insulating part.

  As one aspect, a method for manufacturing a wiring board includes a step of forming a first through hole in a first insulating portion, a step of forming a first conductive portion on an inner wall of the first through hole, and the first through hole. Embedded with an insulating material through the first conductive portion, forming a second conductive portion connected to the first conductive portion on the first insulating portion, and in the second conductive portion, Forming a second through hole exposing a part of the surface of the insulating material; and forming a second insulating portion on the first insulating portion so as to cover the second conductive portion and bury the second through hole. And a step of forming a third conductive portion connected to the second conductive portion in the second insulating portion.

  As one aspect, an electronic device includes a wiring board and an electronic component mounted on the wiring board, and the wiring board includes a first insulating portion having a first through hole, and an inner wall of the first through hole. A first conductive part formed on the first conductive part, an insulating material filling the first through-hole through the first conductive part, a second insulating part formed on the first insulating part, and in the second insulating part And a second conductive part having a second through hole on the insulating material, and a third conductive part connected to the second conductive part in the second insulating part. A conductive portion.

  According to the above aspects, in consideration of the thermal expansion of the insulating material filling the first through hole of the first insulating portion and the thermal expansion of the second insulating portion, the second conductivity mainly resulting from the thermal expansion of the former. In addition to the stress load on the part, the stress load on the third conductive part mainly due to the latter thermal expansion is reduced to prevent the breakage of both as much as possible, thereby realizing a highly reliable wiring board and electronic device.

It is a partial cross section figure which shows the main structures of the wiring board by 1st Embodiment. It is a partial cross section for demonstrating the effect which the wiring board by 1st Embodiment show | plays. It is a flowchart which shows the manufacturing method of the wiring board by 1st Embodiment to process order. It is a schematic sectional drawing which shows the manufacturing method of the wiring board by 1st Embodiment to process order. FIG. 5 is a schematic cross-sectional view subsequent to FIG. 4, showing the method of manufacturing the wiring board according to the first embodiment in the order of steps. It is a schematic diagram which shows the main structure and simulation analysis result of the wiring board by the comparative example of 1st this embodiment. It is a schematic diagram which shows the main structure and simulation analysis result of the wiring board by 1st this embodiment. It is a partial cross section figure which shows the main structures of the electronic device by 2nd Embodiment. It is a partial cross section figure which shows the main structures of the electronic device by the modification of 2nd Embodiment. It is a partial cross section figure which shows the main structures of the conventional wiring board. It is a partial cross section for demonstrating the subject of the conventional wiring board.

  Hereinafter, embodiments of a wiring board and an electronic device will be described in detail with reference to the drawings.

(First embodiment)
In the present embodiment, a wiring board and a manufacturing method thereof are disclosed.

−Schematic configuration of wiring board−
FIG. 1 is a partial cross-sectional view showing the main configuration of the wiring board according to the first embodiment.
This wiring board includes a core substrate 11 that is a first insulating portion, a through electrode 12 that penetrates the core substrate 11, and a buildup layer 13 that is laminated on each of the upper and lower surfaces of the core substrate 11.

  For the core substrate 11, for example, an organic insulating substrate such as a glass epoxy substrate, a polyimide substrate, or a bismaleimide triazine substrate, or an inorganic insulating substrate such as a ceramic substrate can be used.

  The through electrode 12 covers the inner wall of the through hole 11a that is the first through hole formed in the core substrate 11 with the conductive film 21 that is the second conductive portion, and the inside of the through hole 11a is made of an insulating material via the conductive film 21. It is formed by being embedded with a certain resin 22. For the conductive film 21, for example, copper (Cu), silver (Ag), gold (Au), aluminum (Al), or the like can be used. In this embodiment, for example, Cu is used. For example, an epoxy resin can be used as the resin 22.

  In the insulating film 23, the build-up layer 13 includes a land 24 that is a second conductive portion electrically connected to the conductive film 21, a land 25 that is a fourth conductive portion above the land 24, and a land 24 and a land 25. A via 26, which is a third conductive portion to be electrically connected, is formed. For the insulating film 23, for example, a resin material (prepreg) such as an epoxy resin, a phenol resin, or a polyimide resin containing glass filler, glass fiber, carbon fiber, or the like can be used. Various conductive materials can be used for the lands 24 and 25 and the via 26. In this embodiment, for example, Cu is used. The build-up layers 13 on the upper surface and the lower surface of the core substrate 11 are exemplified as a single layer in the present embodiment, but are laminated in a desired plurality of layers.

  The via 26 is a region on the land 24 that includes a portion that is aligned above the conductive film 21, specifically a region that extends over the conductive film 21 and the resin 22 (a region that includes the boundary between the conductive film 21 and the resin 22. In this embodiment, it is provided at two locations as shown in the figure. By forming the via 26 in the region, the land 24 is pressed and thermal expansion of the resin 22 toward the land 24 can be suppressed.

  In the present embodiment, the land 24 is formed with a through hole 24 a that is a second through hole on the resin 22, here in a region between the two vias 26. In the through hole 24a, the resin 22 and the insulating material of the buildup layer 13 are in contact with each other. Further, the land 25 is formed with a through hole 25a, which is a third through hole, at a position aligned above the through hole 24a, in this case, between the two vias 26.

  When thermal expansion occurs in the resin 22, as will be described later, in a configuration in which the land 24 does not have a through hole, stress due to the thermal expansion concentrates on the via 26, and the via 26 may be broken. In the present embodiment, a through hole 24 a is formed in the land 24, and a through hole 25 a is formed in the land 25. Therefore, when the pressure of thermal expansion increases in the resin 22, as shown in FIG. 2, the resin 22 pushes the insulating film 23 of the buildup layer 13 through the through hole 24a and expands in the direction of the arrow A, for example. Along with this, the insulating film 23 expands outward, for example, in the direction of arrow B in the through hole 25a. By this action, the stress due to the thermal expansion on the land 24 is relieved to prevent the land 24 from being destroyed, and the stress due to the thermal expansion on the via 26 is relieved to prevent the via 26 from being destroyed.

-Wiring board manufacturing method-
FIG. 3 is a flowchart showing the method of manufacturing the wiring board according to the present embodiment in the order of steps. 4 and 5 are schematic cross-sectional views showing the method of manufacturing the wiring board according to the present embodiment in the order of steps. 4 and 5, the same reference numerals are given to the structural members corresponding to FIG. 1.

First, as shown in FIG. 4A, the core substrate 11 having the conductive film 31 formed on both the upper surface and the lower surface is prepared (step S1).
The conductive film 31 is made of Cu, for example, and has a thickness of about 0.015 mm. The core substrate 11 has a thickness of about 0.85 mm, for example.

Subsequently, as shown in FIG. 4B, the through electrode 12 is formed on the core substrate 11 (step S2).
Specifically, first, the core substrate 11 is processed using a predetermined drill to form a through hole 11a having a diameter of about 0.15 mm, for example.
Next, the conductive film 21 is formed on the inner wall of the through hole 11a using, for example, an electroless plating method, or an electroless plating method and an electrolytic plating method. The conductive film 21 is made of, for example, Cu and has a thickness of about 0.025 mm.
Next, the inside of the through hole 11 a is filled with a resin 22 that is an insulating material via a conductive film 21. Thus, the through electrode 12 that penetrates the core substrate 11 is formed.

Subsequently, as shown in FIG. 4C, a conductive film 32 is formed (step S3).
Specifically, the conductive film 32 is formed on both the upper surface and the lower surface of the core substrate 11 so as to cover the conductive film 31 and the through electrode 12 by using, for example, an electroless plating method or an electroless plating method and an electrolytic plating method. Form. The conductive film 32 is made of, for example, Cu and has a thickness of about 0.015 mm.

Subsequently, as shown in FIG. 4D, the conductive films 31 and 32 are patterned (step S4).
Specifically, the conductive films 31 and 32 are patterned using a photolithography technique and an etching technique. As a result, a through hole 24 a that exposes a part of the surface of the resin 22 of the through electrode 12 is formed in the conductive film 31, and the conductive films 31 and 32 are removed on the core substrate 11 leaving a part of the land 24. Is formed. The through hole 24a is formed with a diameter of about 0.06 mm, for example. The land 24 is formed with a diameter of, for example, about 0.25 mm. Note that, since the thickness of the conductive film to be etched is different between the formation process of the through hole 24a and the formation process of the land 24, both may be sequentially performed as separate processes. The land 24 needs to appropriately adjust the thickness of the conductive film 32 when the conductive film 32 is formed in order to secure a sufficient conductor area necessary for forming a via in a process described later.

Subsequently, as shown in FIG. 5A, an insulating film 23 is formed (step S5).
Specifically, the insulating film 23 is formed on both the upper surface and the lower surface of the core substrate 11 so as to fill the through holes 24 a and cover the lands 24. The insulating film 23 is formed with a thickness of about 0.075 mm, for example.

Subsequently, as shown in FIG. 5B, a via 26 is formed (step S6).
Specifically, first, an opening for exposing a part of the surface of the land 24 is formed in the insulating film 23. The opening is formed in a region straddling the conductive film 21 and the resin 22 (a region including the boundary between the conductive film 21 and the resin 22), for example, with a diameter of about 0.06 mm and a depth of about 0.03 mm. For forming the opening, for example, a laser such as a carbon dioxide laser, an excimer laser, a UV (Ultra Violet) laser, a YAG (Yttrium Aluminum Garnet) laser is used.
Next, the opening is filled with a conductive material, for example, Cu, using, for example, an electroless plating method, or an electroless plating method and an electrolytic plating method. As a result, the via 26 electrically connected to the land 24 is formed.

Subsequently, as shown in FIG. 5C, lands 25 are formed (step S7).
Specifically, first, for example, by using an electroless plating method or an electroless plating method and an electrolytic plating method, a conductive film is formed on both the upper surface and the lower surface of the core substrate 11 so as to cover the conductive film 31 and the through electrode 12. Form. The conductive film is made of, for example, Cu and has a thickness of about 0.015 mm.
Next, the conductive film is patterned using a photolithography technique and an etching technique. As a result, a through hole 25a exposing a part of the surface of the insulating film 23 is formed in the conductive film in the region between the vias 26, and the conductive film is removed on the insulating film 23 leaving a part of the land 25. It is formed. The through hole 25a is formed at a position aligned above the through hole 24a of the land 24, for example, with a diameter of about 0.06 mm. The land 25 is formed with a diameter of about 0.25 mm, for example. As a result, the buildup layer 13 including the land 24, the land 25 above the land 24, and the via 26 that electrically connects the land 24 and the land 25 is formed in the insulating film 23.

  Thereafter, the process of forming the insulating film 23 (step S5), the process of forming the via 25 (step S6), and the process of forming the land 25 (step S7) are repeated as many times as desired for the buildup layer 13. As described above, the wiring board according to the present embodiment is formed.

In order to confirm the technical effect of the wiring board according to the present embodiment, a simulation analysis based on a comparison with the comparative example (Patent Document 3) of the present embodiment was performed.
FIG. 6 is a schematic diagram illustrating a main configuration of a wiring board and a simulation analysis result according to a comparative example of the present embodiment. FIG. 7 is a schematic diagram showing a main configuration (corresponding to FIG. 1) of the wiring board according to the present embodiment and a simulation analysis result.

  The wiring board according to the comparative example is different from the wiring board according to the present embodiment in that the lands 114 and 115 of the buildup layer 103 do not have through holes. The other points are the same as those of the wiring board according to the present embodiment. That is, the wiring board according to the comparative example includes a core substrate 101, a through electrode 102 that penetrates the core substrate 101, and a buildup layer 103 that is laminated on each of the upper and lower surfaces of the core substrate 101. The through electrode 102 is formed by covering the inner wall of the through hole 101 a formed in the core substrate 101 with the conductive film 111 and filling the through hole 101 a with the resin 112 through the conductive film 111. The buildup layer 103 is formed by forming a land 114 electrically connected to the conductive film 111, a land 115 above the conductive film 111, and a via 116 electrically connecting the land 114 and the land 115 in the insulating film 113. .

  The via 116 is a region on the land 114 that includes a position aligned above the conductive film 111, specifically a region that extends over the conductive film 111 and the resin 112 (a region that includes a boundary between the conductive film 111 and the resin 112. In this embodiment, it is provided at two locations as shown in the figure. By forming the via 116 in the region, the land 114 is pressed, and thermal expansion of the resin 112 toward the land 114 can be suppressed.

  In the comparative example, the land 114 is prevented from being broken due to the thermal expansion of the resin 112, while the stress is easily concentrated on the via 116 that suppresses and suppresses the thermal expansion of the resin 112. Furthermore, since the lower and upper sides of the via 116 are covered with the lands 114 and 115, when the insulating film 113 is thermally expanded, the thermal expansion mainly spreads in the horizontal direction of the insulating film 113, and the inside of the insulating film 113 It becomes easy to concentrate on the via 116. As shown in FIG. 6, a large stress is applied to the upper and lower portions of the via 116, and it can be seen that the stress is relatively large even in the central portion. Due to the stress, the via 116 may break.

  In contrast, in this embodiment, as shown in FIG. 7, when the resin 22 is thermally expanded, the stress generated due to this is suppressed by the via 26, and from the through hole 24 a of the land 24. Dispersed in the insulating film 23 of the buildup layer 13. Further, the stress generated in the via 26 by suppressing the thermal expansion of the resin 22 by pressing and the stress generated due to the thermal expansion of the insulating film 23 are dispersed outward from the through hole 25a of the land 25. The As a result, as shown in FIG. 7, the stress applied to the via 26 is reduced (particularly at the lower and center portions) compared to the via 116 of the comparative example. As a result, the breakage of the via 26 due to the stress is suppressed.

  As described above, according to the present embodiment, in consideration of the thermal expansion of the resin 22 that fills the through hole 11a of the through electrode 12 and the thermal expansion of the insulating film 23 of the buildup layer 13, the former heat is mainly used. Together with the stress load on the land 24 caused by the expansion, the stress load on the via 26 mainly caused by the latter thermal expansion is reduced to prevent breakage of both as much as possible, thereby realizing a highly reliable wiring board.

(Second Embodiment)
In the present embodiment, an electronic device including the wiring board according to the first embodiment is disclosed.
FIG. 8 is a partial cross-sectional view showing the main configuration of the electronic device according to the second embodiment.

This electronic device is configured by mounting an electronic component 20 on the wiring board 10 according to the first embodiment.
The wiring board 10 is the same as the wiring board of FIG. 1, but the build-up layers 13 respectively laminated on the upper surface and the lower surface of the core substrate 11 are laminated in a plurality of layers in the upper and lower sides, and in the illustrated example, in two layers. Has been.

Examples of the electronic component 20 include a semiconductor element (semiconductor chip), a semiconductor package including the semiconductor element, and the like.
A protective film 41 having an opening exposing the surface of the electrode (land 25) is formed on the surfaces of the uppermost layer and the lowermost buildup layer 13. For the protective film 41, for example, a solder resist or the like is used. A bonding material 42 such as a solder bump is provided on the uppermost electrode (land 25) of the wiring board 10. The electrode (land 25) and the electronic component 20 are electrically connected by the bonding material 42.

  According to the present embodiment, considering the thermal expansion of the resin 22 filling the through-hole 11a of the through-electrode 12 and the thermal expansion of the insulating film 23 of the buildup layer 13, the land 24 mainly caused by the former thermal expansion is considered. In addition to the stress load of the latter, the stress load of the via 26 caused mainly by the latter thermal expansion is reduced to prevent both of the breaks as much as possible, and the highly reliable electronic circuit having the highly reliable wiring board 10 is provided. The device is realized.

(Modification)
Hereinafter, modifications of the second embodiment will be described. In this example, the electronic device according to the second embodiment is disclosed as an electronic device mounted on another wiring board.
FIG. 9 is a partial cross-sectional view showing the main configuration of an electronic device according to a modification of the second embodiment.

  The electronic device according to the second embodiment is configured by mounting an electronic device in which an electronic component 20 is mounted on a wiring board 10 on another wiring board 30. A bonding material 42 such as a solder bump is provided on the uppermost layer and the lowermost electrode (land 25) of the wiring substrate 10. In the uppermost layer of the wiring substrate 10, the electrode (land 25) and the electronic component 20 are electrically connected by the bonding material 42. In the lowermost layer of the wiring board 10, the electrode (land 25) and the wiring board 30 are electrically connected by the bonding material 42.

  According to this example, the thermal expansion of the resin 22 filling the through hole 11a of the through electrode 12 and the thermal expansion of the insulating film 23 of the buildup layer 13 are considered, and the land 24 mainly caused by the thermal expansion of the former is considered. A highly reliable electronic device including the highly reliable wiring board 10 that reduces the stress load of the via 26 caused mainly by the latter thermal expansion together with the stress load and prevents the breakage of both vias as much as possible. Is realized.

  Hereinafter, various aspects of the wiring board, the manufacturing method thereof, and the electronic device are collectively described as supplementary notes.

(Appendix 1) a first insulating part having a first through hole;
A first conductive portion formed on the inner wall of the first through hole;
An insulating material that embeds the first through hole through the first conductive portion;
A second insulating part formed on the first insulating part;
A second conductive portion formed in the second insulating portion and connected to the first conductive portion, and having a second through hole on the insulating material;
A wiring board comprising: a third conductive part connected to the second conductive part in the second insulating part.

  (Supplementary note 2) The wiring board according to supplementary note 1, wherein the third conductive portion is formed at a position aligned above the first conductive portion.

  (Additional remark 3) It is connected with the said 3rd electroconductive part on the said 2nd insulating part, and further contains the 4th electroconductive part which has a 3rd through-hole in the site | part aligned above the said 2nd through-hole. The wiring board according to appendix 1 or 2, which is characterized.

  (Appendix 4) The wiring board according to any one of appendices 1 to 3, wherein the second insulating portion is formed on an upper surface and a lower surface of the first insulating portion, respectively.

  (Appendix 5) The wiring board according to any one of appendices 1 to 4, wherein the first insulating portion and the second insulating portion are in contact with each other in the second through hole.

(Appendix 6) forming a first through hole in the first insulating portion;
Forming a first conductive portion on the inner wall of the first through hole;
Filling the first through hole with an insulating material through the first conductive portion;
Forming a second conductive portion connected to the first conductive portion on the first insulating portion;
Forming a second through hole in the second conductive portion to expose a part of the surface of the insulating material;
Forming a second insulating portion on the first insulating portion so as to cover the second conductive portion and bury the second through hole;
Forming a third conductive portion connected to the second conductive portion in the second insulating portion;
A method for manufacturing a wiring board, comprising:

  (Additional remark 7) The said 3rd electroconductive part is formed in the position aligned above the said 1st electroconductive part, The manufacturing method of the wiring board of Additional remark 6 characterized by the above-mentioned.

(Appendix 8) Forming a fourth conductive portion connected to the third conductive portion on the second insulating portion;
The method of manufacturing a wiring board according to appendix 6 or 7, further comprising: forming a third through hole at a position aligned with the second through hole of the fourth conductive portion.

  (Additional remark 9) The said 2nd insulation part is formed in the upper surface and lower surface of a said 1st insulation part, respectively, The manufacturing method of the wiring board of any one of Additional remarks 6-8 characterized by the above-mentioned.

  (Additional remark 10) The said 1st insulating part and the said 2nd insulating part contact in the said 2nd through-hole, The manufacturing method of the wiring board of any one of Additional remark 6-9 characterized by the above-mentioned.

(Appendix 11) a wiring board;
An electronic component mounted on the wiring board,
The wiring board is
A first insulating part having a first through hole;
A first conductive portion formed on the inner wall of the first through hole;
An insulating material that embeds the first through hole through the first conductive portion;
A second insulating part formed on the first insulating part;
A second conductive portion formed in the second insulating portion and connected to the first conductive portion, and having a second through hole on the insulating material;
An electronic device comprising: a third conductive portion connected to the second conductive portion in the second insulating portion.

  (Additional remark 12) The said 3rd electroconductive part is formed in the position aligned above the said 1st electroconductive part, The electronic device of Additional remark 11 characterized by the above-mentioned.

  (Additional remark 13) The said wiring board is connected with the said 3rd electroconductive part on the said 2nd insulating part, and the 4th electroconductive part which has a 3rd through-hole in the site | part aligned above the said 2nd through-hole. The electronic device according to appendix 11 or 12, further comprising:

  (Supplementary note 14) The electronic device according to any one of supplementary notes 11 to 13, wherein the second insulating portion is formed on an upper surface and a lower surface of the first insulating portion, respectively.

  (Supplementary note 15) The electronic device according to any one of Supplementary notes 11 to 14, wherein the first insulating portion and the second insulating portion are in contact with each other in the second through hole.

10, 30 Wiring substrate 11, 101 Core substrate 11a, 24a, 25a, 101a Through hole 12, 102 Through electrode 13, 103 Build-up layer 20 Electronic component 21, 31, 32, 111 Conductive film 22, 112 Resin 23, 113 Insulation Films 24, 25, 114, 115 Lands 26, 116 Via 41 Protective film 42 Bonding material

Claims (11)

A first insulating part having a first through hole;
A first conductive portion formed on the inner wall of the first through hole;
An insulating material that embeds the first through hole through the first conductive portion;
A second insulating part formed on the first insulating part;
A second conductive portion formed in the second insulating portion and connected to the first conductive portion, and having a second through hole on the insulating material;
A wiring board comprising: a third conductive part connected to the second conductive part in the second insulating part.   The wiring board according to claim 1, wherein the third conductive portion is formed at a position aligned above the first conductive portion.   The semiconductor device further comprises a fourth conductive portion connected to the third conductive portion on the second insulating portion and having a third through hole at a position aligned above the second through hole. The wiring board according to 1 or 2.   The wiring board according to claim 1, wherein the second insulating portion is formed on an upper surface and a lower surface of the first insulating portion, respectively.   5. The wiring board according to claim 1, wherein the first insulating portion and the second insulating portion are in contact with each other in the second through hole. Forming a first through hole in the first insulating portion;
Forming a first conductive portion on the inner wall of the first through hole;
Filling the first through hole with an insulating material through the first conductive portion;
Forming a second conductive portion connected to the first conductive portion on the first insulating portion;
Forming a second through hole in the second conductive portion to expose a part of the surface of the insulating material;
Forming a second insulating portion on the first insulating portion so as to cover the second conductive portion and bury the second through hole;
Forming a third conductive portion connected to the second conductive portion in the second insulating portion. A method of manufacturing a wiring board, comprising:   The method for manufacturing a wiring board according to claim 6, wherein the third conductive portion is formed at a position aligned above the first conductive portion. Forming a fourth conductive portion connected to the third conductive portion on the second insulating portion;
The method for manufacturing a wiring board according to claim 6, further comprising: forming a third through hole at a position aligned with the second through hole of the fourth conductive portion.   The method for manufacturing a wiring board according to claim 6, wherein the second insulating portion is formed on an upper surface and a lower surface of the first insulating portion, respectively.   The method for manufacturing a wiring board according to claim 6, wherein the first insulating portion and the second insulating portion are in contact with each other in the second through hole. A wiring board;
An electronic component mounted on the wiring board,
The wiring board is
A first insulating part having a first through hole;
A first conductive portion formed on the inner wall of the first through hole;
An insulating material that embeds the first through hole through the first conductive portion;
A second insulating part formed on the first insulating part;
A second conductive portion formed in the second insulating portion and connected to the first conductive portion, and having a second through hole on the insulating material;
An electronic device comprising: a third conductive portion connected to the second conductive portion in the second insulating portion.