JP2017028164A - Wiring board and manufacturing method of wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high reliable wiring board capable of being manufactured using metal ink by firing at a low temperature.SOLUTION: The wiring board includes: a board; a porous layer formed over the board; and a wiring layer which is formed by firing a metal ink applied on the porous layer. Between the board and the porous layer a gap is formed, and the wiring layer is formed in a part on the porous layer corresponding to the area where the gap is formed.SELECTED DRAWING: Figure 2

Description

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

  Conventionally, a method of manufacturing a wiring board in which a wiring layer is formed on a substrate by applying a metal ink containing metal fine particles on the substrate by a printing method such as an ink jet printing method and baking the substrate is known. (For example, refer to Patent Document 1). In this method, the solvent contained in the metal ink applied on the substrate is removed by baking at a predetermined temperature, and a wiring layer is formed by the remaining metal fine particles.

Japanese Patent Laying-Open No. 2015-12186

  However, when a substrate formed of a resin material or the like is used, the manufactured wiring substrate may be deformed in a firing step when manufacturing the wiring substrate. The reason why the wiring substrate is deformed in such a firing process is that the substrate is heated to a temperature at which the substrate is deformed during firing. For this reason, a method of firing the metal ink at a relatively low temperature that does not deform the substrate is conceivable, but in this case, the removal of the solvent contained in the metal ink is not sufficient, and the wiring layer after firing is not sufficient. In some cases, the solvent remains. As described above, when the solvent remains in the wiring layer, the conductivity in the wiring layer is lowered, and the adhesion between the wiring layer and the substrate is deteriorated, so that the reliability of the wiring substrate is lowered.

  Therefore, there is a demand for a highly reliable wiring board that can be produced by firing at low temperature using a metal ink.

  According to one aspect of the embodiment, a substrate, a porous layer formed on the substrate, and a wiring layer formed by firing a metal ink applied on the porous layer, A gap is provided between the substrate and the porous layer, and the wiring layer is formed on a part of the porous layer corresponding to a region where the gap is provided. It is characterized by being.

  According to the disclosed wiring board, a highly reliable wiring board can be manufactured even if low-temperature baking is performed using metal ink.

Illustration of wiring board The figure which illustrates the wiring board of a 1st embodiment The flowchart which illustrates the manufacturing method of the wiring board of a 1st embodiment. Process drawing of the manufacturing method of the wiring board of 1st Embodiment (1) Process drawing (2) of the manufacturing method of the wiring board of 1st Embodiment Process drawing of the manufacturing method of the wiring board of the first embodiment (3) Process drawing of the manufacturing method of the wiring board of the first embodiment (4) Process drawing of the manufacturing method of the wiring board of the first embodiment (5) Process drawing of the manufacturing method of the wiring board of the first embodiment (6) Process drawing of the manufacturing method of the wiring board of the first embodiment (7) The flowchart which illustrates the manufacturing method of the wiring board of a 2nd embodiment. Process drawing of the manufacturing method of the wiring board of 2nd Embodiment (1) Process drawing of the manufacturing method of the wiring board of 2nd Embodiment (2) Process drawing of the manufacturing method of the wiring board of 2nd Embodiment (3) Process drawing of the manufacturing method of the wiring board of 2nd Embodiment (4)

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

  By the way, as a method for producing a highly reliable wiring board using metal ink, a porous layer is formed on an insulating material on the board, and wiring is formed on the porous layer formed on the board. A method of forming the layer is conceivable. Specifically, as shown in FIG. 1, a porous layer 930 is formed on a substrate 910 and a wiring layer 970 is formed on the porous layer 930. 1A is a top view of the wiring board, and FIG. 1B is a cross-sectional view taken along the alternate long and short dash line 1A-1B in FIG. 1A.

  In this manner, by forming the wiring layer 970 on the porous layer 930, the solvent contained in the metal ink can be absorbed by the porous layer 930. Therefore, the removal of the solvent is promoted, and the wiring layer is baked after firing. The solvent contained in 970 can be reduced.

  However, if the porous layer 930 only absorbs the solvent, the removal of the solvent contained in the wiring layer 970 after firing is insufficient, the conductivity in the wiring layer is reduced, and the adhesion between the wiring layer and the substrate is reduced. There are cases in which it is not possible to sufficiently solve the problem.

[First Embodiment]
(Wiring board)
Next, the wiring board in the first embodiment will be described with reference to FIG.

  As shown in FIG. 2, the wiring board 1 in this embodiment includes a substrate 10, a porous layer 30, an insulating layer 40, a wiring layer 70, and the like. FIG. 2A is a top view of the wiring board in the present embodiment, and FIG. 2B is a cross-sectional view taken along the alternate long and short dash line 2A-2B in FIG.

  The substrate 10 is a thin plate-like or film-like member formed of an insulating material, and is formed of, for example, a resin material such as an epoxy resin, a polyimide resin, a PET (Poly Ethylene Terephthalate) resin, or a polycarbonate resin.

  The porous layer 30 is formed on the substrate 10, and a gap G is formed between the substrate 10 and the porous layer 30. Specifically, the porous layer 30 is supported by a support portion in contact with the substrate 10 at the peripheral portion of the porous layer 30, and the gap G is formed in a region inside the support portion of the porous layer 30. The In the present embodiment, this support portion is a part of the porous layer 30.

  In the wiring substrate 1 according to the present embodiment, the gap G, that is, the gap t1 between the substrate 10 and the porous layer 30 in the area where the gap G is formed is, for example, about 5 μm. The thickness t2 of the porous layer 30 in the formed region is, for example, about 5 μm.

The porous layer 30 is made of an insulating material and has fine holes. Specifically, for example, the porous layer 30 is formed of particles of an inorganic material such as silica (SiO ₂ ), and micropores are formed by gaps between the particles of the inorganic material.

  The porous layer 30 has an opening 30 h that penetrates in the thickness direction of the porous layer 30 in the region where the gap G is formed. The opening 30h formed in the porous layer 30 is formed in the vicinity of a region where the wiring layer 70 will be formed later. For example, the opening 30h is formed on both sides in the vicinity of the region where the wiring layer 70 is formed. Accordingly, the opening 30 h formed in the porous layer 30 is formed in a part of the region where the wiring layer 70 is not formed. The size and number of the openings 30h formed in the porous layer 30 are formed within a range in which the shape and the like of the porous layer 30 are maintained.

  The insulating layer 40 is formed so as to cover the substrate 10, a side surface around the porous layer 30, and a part of the upper surface around the porous layer 30. The thickness t3 from the surface of the substrate 10 to the upper surface of the insulating layer 40 is the thickness t1 of the gap G between the substrate 10 and the porous layer 30 and the thickness of the porous layer 30 in the region where the gap G is formed. A value larger than the sum of t2 is preferable. Thereby, the shape of the part containing the support part in the peripheral part of the porous layer 30 on the board | substrate 10 is maintainable with the insulating layer 40. FIG. For example, the thickness t3 from the surface of the substrate 10 to the upper surface of the insulating layer 40 may be about 11 μm.

  The wiring layer 70 is formed by applying the metal ink 50 on the porous layer 30 and baking it, and is formed on a part of the porous layer 30 corresponding to the region where the gap G is formed. Has been. The thickness of the wiring layer 70 thus formed is about 2 μm, for example. 2 shows a case where the shape of the wiring layer 70 is a single linear wiring pattern for the sake of convenience, the shape of the wiring layer 70 is not limited to this shape, but may be various. It can be formed in a shape.

(Method for manufacturing a wiring board)
Next, a method for manufacturing a wiring board in the first embodiment will be described with reference to FIGS. FIG. 3 is a flowchart of the method for manufacturing a wiring board in the present embodiment, and FIGS.

  First, in step 11 (S11), the sacrificial layer 20 is formed on the substrate 10. The sacrificial layer 20 is for forming the gap G, and in this embodiment, the sacrificial layer 20 is formed to have a thickness of about 5 μm. Specifically, as shown in FIG. 4, a photosensitive resin film is entirely coated on the substrate 10, and the photosensitive resin film is exposed and developed to form a gap G on the substrate 10. A sacrificial layer 20 is formed in the region. Alternatively, the sacrificial layer 20 may be formed on the substrate 10 by transferring a preliminarily molded photosensitive resin onto the substrate 10. The substrate 10 is a material made of a resin material or the like, and is made of a material that does not deform in the subsequent step of firing the metal ink 50. The sacrificial layer 20 may be any material that can be removed by the removal liquid 60 and may be formed of a metal material or the like. FIG. 4A is a top view in this step, and FIG. 4B is a cross-sectional view taken along the alternate long and short dash line 4A-4B in FIG.

  Next, in step 12 (S12), the porous layer 30 is formed so as to cover the sacrificial layer 20. Specifically, as shown in FIG. 5, a part of the sacrificial layer 20 on the substrate 10 around the sacrificial layer 20 is sacrificed by transferring a preformed sheet-like member onto the substrate 10 and the sacrificial layer 20. A porous layer 30 covering the upper surface of the layer 20 and the surrounding side surfaces is formed. The formed porous layer 30 is formed to have a thickness of about 5 μm on the sacrificial layer 20, and the opening 30 h in the porous layer 30 is a part of the region where the sacrificial layer 20 is formed. It is formed in the part. Therefore, in this state, the sacrificial layer 20 is exposed in the opening 30 h in the porous layer 30. The porous layer 30 is formed of a material that does not deform or the like in the subsequent step of firing the metal ink 50. The porous layer 30 is formed so that the speed at which the metal ink 50 penetrates is faster in the thickness direction than in the surface direction. As a result, the line width and the like of the wiring layer 70 formed with the metal ink 50 can be formed with a desired line width and the like with high accuracy. 5A is a top view in this step, and FIG. 5B is a cross-sectional view taken along the alternate long and short dash line 5A-5B in FIG. 5A.

  Next, in step 13 (S13), the insulating layer 40 is formed so as to surround the periphery of the porous layer 30 in plan view. In the present embodiment, the insulating layer 40 is formed so that the thickness from the surface of the substrate 10 to the upper surface of the insulating layer 40 is about 11 μm. Specifically, as shown in FIG. 6, a part of the porous layer 30 on the substrate 10 around the porous layer 30, the porous layer 30, is transferred by transferring a pre-molded sheet-like insulating layer 40 onto the substrate 10. An insulating layer 40 is formed to cover a side surface around 30 and a part of the upper surface from the side surface. The insulating layer 40 may be formed by applying an ultraviolet curable resin on the substrate 10 by an inkjet printing method, and then irradiating the ultraviolet ray to cure the ultraviolet curable resin. The formed insulating layer 40 is formed on a part of the side surface and the upper surface around the porous layer 30, and the region where the wiring layer 70 is formed on the porous layer 30 and the opening of the porous layer 30. It is not formed in the region where 30h is formed. Therefore, the sacrificial layer 20 in the upper surface of the porous layer 30 and the opening 30 h of the porous layer 30 is exposed inside the region surrounded by the insulating layer 40. 6A is a top view in this step, and FIG. 6B is a cross-sectional view taken along the alternate long and short dash line 6A-6B in FIG. 6A.

  Next, in step 14 (S14), the metal ink 50 for forming the wiring layer 70 is applied on the porous layer 30. Specifically, as shown in FIG. 7, a metal ink 50 is applied to a part on the porous layer 30 corresponding to the region where the sacrificial layer 20 is formed by an ink jet printing method. The amount of ejection when the metal ink 50 is applied can be determined by the thickness of the metal ink 50 to be applied, the application speed, and the like. In the present embodiment, the metal ink 50 is applied so that the wiring layer 70 formed of the metal ink 50 has a thickness of 2 μm. As the metal ink 50, for example, an ink containing metal fine particles such as silver (Ag) and copper (Cu) and an organic solvent can be used. Since such an organic solvent is removed by firing such a metal ink 50, the wiring layer 70 can be formed from remaining metal fine particles such as silver and copper. The solvent included in the metal ink 50 may include a solvent other than the organic solvent.

  Further, the opening 30 h in the porous layer 30 is preferably formed in the vicinity of a region where the metal ink 50 for forming the wiring layer 70 is applied. Thus, in a later step, the removal liquid 60 is supplied from the opening 30h of the porous layer 30 and the sacrificial layer 20 is removed, so that the metal ink 50 is applied to the region below the porous layer 30. The gap G can be easily formed.

  In the present embodiment, when the metal ink 50 is applied on the porous layer 30, a part of the metal fine particles contained in the metal ink 50 enters the micropores of the porous layer 30. The adhesive force between the formed porous layer 30 and the wiring layer 70 becomes strong. Such an effect is called an anchor effect. The metal ink 50 may be applied by a printing method other than the ink jet printing method. For convenience, in FIG. 7 to FIG. 10, the metal fine particles included in the metal ink 50 entering the micropores in the porous layer 30 are omitted. FIG. 7A is a top view in this step, and FIG. 7B is a cross-sectional view taken along the alternate long and short dash line 7A-7B in FIG. 7A.

  Next, in step 15 (S15), the metal ink 50 applied on the porous layer 30 is dried. Specifically, the metal ink 50 applied on the porous layer 30 is dried at room temperature or a temperature lower than the temperature at which the metal ink 50 in the subsequent process is baked. By drying the metal ink 50 in this way, the shape of the metal ink 50 applied on the porous layer 30 can be maintained.

  Next, in step 16 (S 16), the sacrificial layer 20 is removed by supplying the removal liquid 60 from the opening 30 h formed in the porous layer 30. Specifically, as shown in FIG. 8, the substrate is formed between the substrate 10 and the porous layer 30 by supplying the removal liquid 60 from the opening 30 h formed in the porous layer 30 by an ink jet printing method. The sacrificial layer 20 is removed. By removing the sacrificial layer 20 in this manner, the gap G can be formed in the region where the sacrificial layer 20 is removed. The removal liquid 60 is supplied from the direction indicated by the broken-line arrow in FIG. The removal liquid 60 can be selected according to the material of the sacrificial layer 20. For example, when the sacrificial layer 20 is a photosensitive resin, a developer can be used, and when the sacrificial layer 20 is a metal. An etching solution such as an acid can be used. Although FIG. 9 shows a state in which all the sacrificial layer 20 formed on the substrate 10 is removed, the sacrificial layer 20 may not be completely removed. For example, even if a part of the sacrificial layer 20 remains, it is sufficient that the gap G is formed below the porous layer 30 in the region where the metal ink 50 is applied. The removing liquid 60 supplied from the opening 30h of the porous layer 30 can be removed by drying, baking, or the like. In this embodiment, since the insulating layer 40 is formed so as to surround the side surface around the porous layer 30, the removal liquid 60 is removed when the sacrificial layer 20 is removed by the removal liquid 60. Leakage around 30 can be prevented. As a result, even if another wiring layer or the like is formed around the porous layer 30, the removal liquid 60 does not leak out of the porous layer 30. It does not affect electrical characteristics such as resistance. 8A is a top view in this step, and FIG. 8B is a cross-sectional view taken along the alternate long and short dash line 8A-8B in FIG. 8A. FIG. 9A is a top view in this step, and FIG. 9B is a cross-sectional view taken along the alternate long and short dash line 9A-9B in FIG. 9A.

  Next, in step 17 (S17), the metal ink 50 applied on the porous layer 30 is baked. Specifically, as shown in FIG. 10, the metal ink 50 applied on the porous layer 30 is baked at about 125 ° C., thereby removing the organic solvent contained in the metal ink 50, and the metal ink 50. The wiring layer 70 is formed from the metal fine particles contained in the substrate. Thereby, the wiring board in this embodiment can be produced. 10A is a top view in this step, and FIG. 10B is a cross-sectional view taken along the alternate long and short dash line 10A-10B in FIG. 10A.

  Here, when a wiring layer having a film thickness of 2 μm is formed by directly applying and baking a metal ink on a substrate on which a porous layer is not formed, an organic solvent contained in the metal ink is removed. It is assumed that the firing temperature necessary for sufficient removal is 150 ° C. In the method for manufacturing a wiring board in the present embodiment, the organic solvent is also removed from the side of the porous layer to which the metal ink is applied, and thus the firing temperature necessary for sufficiently removing the organic solvent contained in the metal ink. The temperature can be lower than 150 ° C., for example, 125 ° C. Therefore, in the present embodiment, the organic solvent contained in the metal ink 50 can be sufficiently removed at a temperature lower than that in the past.

  As described above, in the wiring board according to the present embodiment, since the gap G is formed between the substrate 10 and the porous layer 30, the organic solvent contained in the metal ink 50 is not only the upper surface of the metal ink 50, It is also removed from the gap G through the porous layer 30 under the metal ink 50. Thereby, the removal of the organic solvent contained in the metal ink 50 can be promoted, and the organic solvent remaining in the wiring layer 70 after firing can be reduced as much as possible. Therefore, in this embodiment, even when the substrate 10 made of a resin material having low heat resistance is used, the conductivity in the wiring layer is good, and the adhesion between the wiring layer and the substrate is good. A highly reliable wiring board with good performance can be obtained.

[Second Embodiment]
The second embodiment is a method for manufacturing a wiring board in which the wiring board in the first embodiment is manufactured by a method different from that in the first embodiment.

  A method for manufacturing a wiring board according to the second embodiment will be described with reference to FIGS. FIG. 11 is a flowchart of the manufacturing method of the wiring board in the present embodiment, and FIGS. 12 to 15 are process diagrams of the manufacturing method of the wiring board in the present embodiment. In the wiring board manufacturing method according to this embodiment, steps 21 to 23 shown in FIG. 11 are the same processes as those in the first embodiment. 6 will be described.

  First, in step 21 (S21), the sacrificial layer 20 is formed on the substrate 10. The sacrificial layer 20 is for forming the gap G, and in this embodiment, the sacrificial layer 20 is formed to have a thickness of about 5 μm. Specifically, as shown in FIG. 4, a photosensitive resin film is coated on the entire surface of the substrate 10, and the photosensitive resin film is exposed and developed to form a gap G on the substrate 10. A sacrificial layer 20 is formed in the region.

  Next, in step 22 (S22), the porous layer 30 is formed so as to cover the sacrificial layer 20. Specifically, as shown in FIG. 5, a part of the sacrificial layer 20 on the substrate 10 around the sacrificial layer 20 is sacrificed by transferring a preformed sheet-like member onto the substrate 10 and the sacrificial layer 20. A porous layer 30 covering the upper surface of the layer 20 and the surrounding side surfaces is formed.

  Next, in step 23 (S23), the insulating layer 40 is formed so as to surround the periphery of the porous layer 30 in plan view. In the present embodiment, the insulating layer 40 is formed so that the thickness from the surface of the substrate 10 to the upper surface of the insulating layer 40 is about 11 μm. Specifically, as shown in FIG. 6, a part of the porous layer 30 on the substrate 10 around the porous layer 30, the porous layer 30, is transferred by transferring a pre-molded sheet-like insulating layer 40 onto the substrate 10. An insulating layer 40 is formed to cover a side surface around 30 and a part of the upper surface from the side surface.

  Next, in step 24 (S24), the sacrificial layer 20 is removed by supplying the removal liquid 60 from the opening 30h formed in the porous layer 30. Specifically, as shown in FIG. 12, the substrate is formed between the substrate 10 and the porous layer 30 by supplying the removal liquid 60 from the opening 30 h formed in the porous layer 30 by an ink jet printing method. The sacrificial layer 20 is removed. By removing the sacrificial layer 20 in this way, the gap G can be formed in the region where the sacrificial layer 20 was formed. The removal liquid 60 is supplied from the direction indicated by the broken-line arrow in FIG. The removal liquid 60 can be selected according to the material of the sacrificial layer 20. For example, when the sacrificial layer 20 is a photosensitive resin, a developer can be used, and when the sacrificial layer 20 is a metal. An etching solution such as an acid can be used. Although FIG. 13 shows a state where all the sacrificial layer 20 formed on the substrate 10 is removed, the sacrificial layer 20 may not be completely removed. For example, even if a part of the sacrificial layer 20 remains, it is sufficient that the gap G is formed below the porous layer 30 in the region where the metal ink 50 is applied. The removing liquid 60 supplied from the opening 30h of the porous layer 30 can be removed by drying, baking, or the like. In this embodiment, since the insulating layer 40 is formed so as to surround the side surface around the porous layer 30, the removal liquid 60 is removed when the sacrificial layer 20 is removed by the removal liquid 60. Leakage around 30 can be prevented. As a result, even if another wiring layer or the like is formed around the porous layer 30, the removal liquid 60 does not leak out of the porous layer 30. It does not affect electrical characteristics such as electrical resistance. 12A is a top view in this step, and FIG. 12B is a cross-sectional view taken along the alternate long and short dash line 12A-12B in FIG. 12A. FIG. 13A is a top view in this step, and FIG. 13B is a cross-sectional view taken along the alternate long and short dash line 13A-13B in FIG.

  Next, in step 25 (S25), the metal ink 50 for forming the wiring layer 70 is applied on the porous layer 30. Specifically, as shown in FIG. 14, the metal ink 50 is applied to a part on the porous layer 30 corresponding to the region where the gap G is formed by the ink jet printing method. The amount of ejection when applying the metal ink 50 can be determined by the thickness of the metal ink 50 to be applied, the application speed of the metal ink 50, and the like. In the present embodiment, the metal ink 50 is applied so that the wiring layer 70 formed of the metal ink 50 has a thickness of 2 μm. As the metal ink 50, for example, an ink containing metal fine particles such as silver (Ag) and copper (Cu) and an organic solvent can be used. Since such an organic solvent is removed by firing such a metal ink 50, the wiring layer 70 can be formed from remaining metal fine particles such as silver and copper.

  The metal ink 50 may be applied by a printing method other than the ink jet printing method. After applying the metal ink 50, the metal ink 50 may be dried if necessary. For convenience, in FIG. 14 and FIG. 15, metal fine particles included in the metal ink 50 entering the micropores in the porous layer 30 are omitted. FIG. 14A is a top view in this step, and FIG. 14B is a cross-sectional view taken along the alternate long and short dash line 14A-14B in FIG.

  Next, in step 26 (S26), the metal ink 50 applied on the porous layer 30 is baked. Specifically, as shown in FIG. 15, the metal ink 50 applied onto the porous layer 30 is baked at about 125 ° C., thereby removing the organic solvent contained in the metal ink 50, and the metal ink 50. The wiring layer 70 is formed from the metal fine particles contained in the substrate. Thereby, the wiring board in this embodiment can be produced. FIG. 15A is a top view in this step, and FIG. 15B is a cross-sectional view taken along the alternate long and short dash line 15A-15B in FIG. 15A.

  As described above, in the wiring board according to the present embodiment, since the gap G is formed between the substrate 10 and the porous layer 30, the organic solvent contained in the metal ink 50 is not only the upper surface of the metal ink 50, It is also removed from the gap G through the porous layer 30 under the metal ink 50. Thereby, the removal of the organic solvent contained in the metal ink 50 can be promoted, and the organic solvent remaining in the wiring layer 70 after firing can be reduced as much as possible. Therefore, in this embodiment, even when a substrate formed of a resin material having low heat resistance is used, the conductivity in the wiring layer is good, and the adhesion between the wiring layer and the substrate is also good. It is possible to obtain a highly reliable wiring board in which the resistance is good.

  Further, in the present embodiment, it is possible to omit the step of drying the metal ink, and thus it is possible to manufacture a wiring board at a low cost.

  Although the embodiments have been described in detail above, the present invention is not limited to specific embodiments, and various modifications and changes can be made within the scope described in the claims.

Regarding the above embodiment, the following additional notes are disclosed.
(Appendix 1)
A substrate,
A porous layer formed on the substrate;
A wiring layer formed by firing a metal ink applied on the porous layer;
Have
A gap is provided between the substrate and the porous layer,
The wiring board, wherein the wiring layer is formed on a part of the porous layer corresponding to a region where the gap is provided.
(Appendix 2)
The wiring substrate according to appendix 1, wherein the porous layer is supported in contact with the substrate at a peripheral portion of the porous layer.
(Appendix 3)
The wiring board according to appendix 1 or 2, wherein the porous layer has an opening penetrating in a thickness direction of the porous layer in a region where the void is formed.
(Appendix 4)
4. The wiring board according to any one of appendices 1 to 3, wherein an insulating layer is formed to cover a side surface around the porous layer and a part of an upper surface from the side surface.
(Appendix 5)
The thickness from the surface of the substrate to the upper surface of the insulating layer is greater than the sum of the gap distance between the substrate and the porous layer and the thickness of the porous layer in the region where the void is formed. The wiring board according to appendix 4, characterized by:
(Appendix 6)
The wiring board according to any one of supplementary notes 1 to 5, wherein the board includes any one of an epoxy resin, a polyimide resin, a PET resin, and a polycarbonate resin.
(Appendix 7)
Forming a sacrificial layer on the substrate;
Forming a porous layer covering the top and side surfaces of the sacrificial layer on the substrate;
Applying a metal ink on the porous layer;
After the step of forming the porous layer, a step of forming a void in the region where the sacrificial layer has been removed by supplying a removing liquid and removing the sacrificial layer;
Firing the metal ink after removing the sacrificial layer;
A method of manufacturing a wiring board, comprising:
(Appendix 8)
The method for manufacturing a wiring board according to appendix 7, wherein the step of forming the gap is performed after the step of applying the metal ink.
(Appendix 9)
The porous layer is provided with an opening that penetrates the porous layer in the thickness direction and exposes the sacrificial layer,
9. The method of manufacturing a wiring board according to appendix 7 or 8, wherein in the step of removing the sacrificial layer, the removing liquid is supplied from the opening.
(Appendix 10)
The method of manufacturing a wiring board according to any one of appendices 7 to 9, wherein the step of applying the metal ink is a step of applying the metal ink by an ink jet printing method.
(Appendix 11)
11. The method of manufacturing a wiring board according to any one of appendices 7 to 10, wherein the step of forming the porous layer forms the porous layer by a transfer method.
(Appendix 12)
12. The method for manufacturing a wiring board according to any one of appendices 7 to 11, wherein the step of forming the gap is to supply the removal liquid by an ink jet printing method.

DESCRIPTION OF SYMBOLS 1 Wiring board 10 Board | substrate 20 Sacrificial layer 30 Porous layer 30h Opening 40 Insulating layer 50 Metal ink 60 Removal liquid 70 Wiring layer G Gap

Claims (8)

A substrate,
A porous layer formed on the substrate;
A wiring layer formed by firing a metal ink applied on the porous layer;
Have
A gap is provided between the substrate and the porous layer,
The wiring board, wherein the wiring layer is formed on a part of the porous layer corresponding to a region where the gap is provided.   The wiring substrate according to claim 1, wherein the porous layer is supported in contact with the substrate at a peripheral portion of the porous layer.   The wiring substrate according to claim 1, wherein the porous layer has an opening penetrating in a thickness direction of the porous layer in a region where the void is formed.   The wiring board according to claim 1, wherein an insulating layer is formed to cover a side surface around the porous layer and a part of an upper surface from the side surface. Forming a sacrificial layer on the substrate;
Forming a porous layer covering the top and side surfaces of the sacrificial layer on the substrate;
Applying a metal ink on the porous layer;
After the step of forming the porous layer, a step of forming a void in the region where the sacrificial layer has been removed by supplying a removing liquid and removing the sacrificial layer;
Firing the metal ink after removing the sacrificial layer;
A method of manufacturing a wiring board, comprising:   The method for manufacturing a wiring board according to claim 5, wherein the step of forming the void is performed after the step of applying the metal ink. The porous layer is provided with an opening that penetrates the porous layer in the thickness direction and exposes the sacrificial layer,
The method for manufacturing a wiring board according to claim 5, wherein in the step of removing the sacrificial layer, the removing liquid is supplied from the opening.   8. The method for manufacturing a wiring board according to claim 5, wherein the step of applying the metal ink is a step of applying the metal ink by an ink jet printing method.

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