WO2016114400A1

WO2016114400A1 - Laminated wiring structure, and methdod for forming laminated wiring structure

Info

Publication number: WO2016114400A1
Application number: PCT/JP2016/051185
Authority: WO
Inventors: 仲島　厚志
Original assignee: コニカミノルタ株式会社
Priority date: 2015-01-15
Filing date: 2016-01-15
Publication date: 2016-07-21
Also published as: JPWO2016114400A1

Abstract

In order to provide a laminated wiring structure and a method for forming the laminated wiring structure that ensure the electrical interlayer connection between upper and lower electrodes, which are laminated with an insulating layer therebetween, and that provide reliable conductivity, the present invention is equipped with a lower electrode 3, an insulating layer 4 provided above the lower electrode 3, and an upper electrode 5 provided above the insulating layer 4. A contact hole 41 is provided in the insulating layer 4. A post electrode 6 for achieving conductivity between the lower electrode 3 and the upper electrode 5 is provided in the contact hole 41. A conductive layer 7 is formed between the post electrode 6 and the upper electrode 5 by using a conductive ink.

Description

Wiring multilayer structure and method for forming wiring multilayer structure

The present invention relates to a wiring laminated structure and a method for forming a wiring laminated structure, and more specifically, a wiring laminated structure and a wiring laminated structure in which upper and lower electrodes laminated with an insulating layer interposed therebetween are electrically connected by a post electrode. About the body.

In a structure in which electrodes are stacked with an insulating layer sandwiched between them, when it is necessary to connect the upper and lower electrodes, a contact hole is formed in the insulating layer, and a via electrode is formed in the contact hole to electrically connect the upper and lower electrodes. A connection is made.

In a typical photolithography process, interlayer connection is achieved by forming a via hole and an upper electrode by a method such as plating after forming a through hole in an insulating layer provided on the lower electrode.

JP 2004-179181 A

The present inventor is examining a method for producing an electronic device directly by printing or coating (also referred to as printed electronics).

Taking a thin film transistor as an example of an electronic device, it has been attempted to form an electrode material, an insulating material, a semiconductor material, and the like in a process by printing or coating (hereinafter sometimes referred to as a wet process).

However, as a method for manufacturing an electronic device, a technique for achieving the above-described interlayer connection with high reliability is sufficiently established when the above-described wet process is included, particularly when all layers are formed by a wet process. It is hard to say that it is.

Patent Document 1 proposes forming a photo-curing ceramic layer as an insulating layer after forming a conductor pattern layer to be a via electrode.

However, in the technique of Patent Document 1, when the upper electrode is stacked on the via electrode, the electrical connection between the via electrode and the upper electrode is likely to be unstable, so that reliable conduction is obtained. There is room for further improvement from the viewpoint.

Accordingly, an object of the present invention is to provide an electrical interlayer connection between upper and lower electrodes laminated with an insulating layer interposed therebetween, and to provide a reliable electrical connection and a method for forming a wiring multilayer structure Is to provide.

Further, other problems of the present invention will become apparent from the following description.

The above problems are solved by the following inventions.

1.
A lower electrode, an insulating layer provided on the lower electrode, and an upper electrode provided on the insulating layer,
A contact hole is provided in the insulating layer, and a post electrode for obtaining conduction between the lower electrode and the upper electrode is provided in the contact hole,
A wiring laminated structure in which a conductive layer formed of conductive ink is interposed between the post electrode and the upper electrode.
2.
2. The wiring laminated structure according to 1 above, wherein the conductive layer and the upper electrode are fired simultaneously.
3.
The wiring laminated structure according to 1 or 2, wherein the lower electrode is supported by a base material.
4).
4. The wiring laminate structure according to 3 above, wherein the substrate is a film.
5.
Forming a post electrode on the lower electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the post electrode;
Applying a conductive ink for forming a conductive layer so as to be in contact with the post electrode;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
A method for forming a wiring laminated structure having:
6).
Forming a post electrode on the lower electrode;
Applying a conductive ink for forming a conductive layer so as to be in contact with the post electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the conductive ink;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
A method for forming a wiring laminated structure having:
7).
Forming a post electrode on the lower electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the post electrode;
Forming an upper electrode having an opening exposing the post electrode on the insulating layer;
Applying a conductive ink for forming a conductive layer so as to be in contact with the upper electrode and the post electrode through the opening of the upper electrode;
A method for forming a wiring laminated structure having:
8).
8. The method for forming a wiring laminated structure according to 7, wherein the upper electrode is formed by transferring an electrode film that has been previously patterned into a shape having an opening.
9.
9. The method for forming a wiring laminated structure according to any one of 5 to 8, wherein the post electrode is formed by any one of screen printing, gravure printing, flexographic printing, and inkjet printing.
10.
10. The method for forming a wiring laminated structure according to any one of 5 to 9, wherein the conductive ink is applied by ink jet printing.
11.
11. The method for forming a wiring laminated structure according to any one of 5 to 10, wherein the upper electrode is formed by transfer printing.
12
12. The method for forming a wiring laminated structure according to any one of 5 to 11, wherein the conductive ink is baked after forming the upper electrode.
13
13. The method for forming a wiring laminated structure according to any one of 5 to 12, wherein the lower electrode is supported on a base material.
14
14. The method for forming a wiring laminated structure according to 13, wherein the substrate is a film.
15.
Applying a conductive ink to form a post electrode on the lower electrode;
Forming a post electrode precursor in which the conductive ink remains on at least a part of the surface by drying a part of the conductive ink; and
Forming an insulating layer on the lower electrode so as to expose at least part of the conductive ink;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
Baking the conductive ink after forming the upper electrode to form the post electrode precursor as a post electrode;
A method for forming a wiring laminated structure having:
16.
16. The method for forming a wiring laminated structure according to 15, wherein the conductive ink for forming the post electrode is applied by ink jet printing.

According to the present invention, there is provided a wiring laminated structure and a method for forming the wiring laminated structure that can ensure reliable electrical connection between upper and lower electrodes laminated with an insulating layer interposed therebetween, and provide reliable conduction. Can be provided.

Sectional drawing which explains notionally an example of wiring lamination structure Sectional drawing which illustrates notionally an example of the formation method of the wiring laminated structure shown in FIG. Sectional drawing explaining notionally other examples of wiring lamination structure Sectional drawing which illustrates notionally an example of the formation method of the wiring laminated structure shown in FIG. Sectional drawing which illustrates further another example of wiring lamination structure Sectional drawing which illustrates notionally an example of the formation method of the wiring laminated structure shown in FIG. Sectional drawing explaining notionally an example of the wiring laminated structure in which the post electrode is formed in a part in the contact hole of an insulating layer Sectional drawing which illustrates notionally an example of the formation method of the wiring laminated structure shown in FIG. Sectional drawing which conceptually demonstrates the other aspect of the formation method of a wiring laminated structure Sectional drawing explaining notionally an example of the thin-film transistor provided with the wiring laminated structure

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view conceptually illustrating an example of a wiring laminated structure.

In FIG. 1, reference numeral 1 denotes a wiring laminated structure, which includes a base material 2, a lower electrode 3 provided on the base material 2, an insulating layer 4 provided on the lower electrode 3, and the insulating layer 4. And an upper electrode 5 provided on the top. That is, the lower electrode 3 and the upper electrode 5 are stacked with the insulating layer 4 interposed therebetween.

The insulating layer 4 is provided with a contact hole 41 that penetrates the insulating layer 4. In the contact hole 41, a post electrode 6 for obtaining electrical connection between the lower electrode 3 and the upper electrode 5 is provided. The contact hole 41 may be blocked by the post electrode 6 as in the illustrated example.

Further, a conductive layer 7 made of conductive ink is interposed between the post electrode 6 and the upper electrode 5.

Thereby, an electrical interlayer connection between the lower electrode 3 and the upper electrode 5 is ensured, and an effect of obtaining reliable conduction is obtained.

FIG. 2 is a cross-sectional view conceptually illustrating an example of a method for forming the wiring laminated structure shown in FIG.

As shown in FIG. 2A, the lower electrode 3 is formed on the substrate 2.

The lower electrode 3 can be formed, for example, by applying or printing ink containing a conductive material.

Examples of the conductive material include metals such as Ag, Au, Pt, Pd, Cr, Se, and Ni, oxide conductive materials such as ITO and ZnO, and conductive polymers. The ink can contain such a conductive material dissolved or dispersed in an organic solvent and / or water. Examples of preferred inks include inks containing PEDOT-PSS in water or isopropyl alcohol (abbreviated as IPA), water-based Ag nanoinks containing Ag particles in polar solvents such as ethanol and IPA in addition to water, and Ag particles. Examples thereof include solvent-based Ag nanoinks in which is added in a hydrocarbon-based solvent such as tetradecane.

As a method for forming the coating, a known coating method such as dipping, spin coating, knife coating, bar coating, blade coating, squeeze coating, reverse roll coating, gravure roll coating, curtain coating, spray coating, die coating or the like is used. be able to.

Also, as a method for forming a print, for example, a printing method known per se such as screen printing, offset printing, flexographic printing, gravure printing, ink jet printing and the like can be used. Among these, the offset printing method is preferable. The offset printing method is not particularly limited, but the microcontact printing method, the reverse printing method, etc. are suitable as a printing method for the lower electrode 3 in the electronic device because the flatness of the coating film is good and high-resolution printing can be handled. It is.

The lower electrode 3 can also be formed by photolithography or the like.

It is also preferable to perform firing after forming the lower electrode 3.

Next, as shown in FIG. 2B, a post electrode 6 is formed on the lower electrode 3.

The post electrode 6 can be formed using, for example, the method described for the lower electrode 3.

From the viewpoint of easily imparting a desired formation height to the post electrode 6, printing methods such as screen printing, gravure printing, flexographic printing, and inkjet printing, and photolithography can be preferably exemplified.

In addition, in particular, inkjet printing, gravure printing, photolithography, and the like are preferable from the viewpoint of suitably responding to a request for reducing the diameter of the post electrode 6.

In the case of using gravure printing, gravure offset printing is particularly suitable. Gravure offset printing is a method in which ink supplied to a gravure plate (intaglio) is transferred to a rotating rubber roll and then adhered to an object (work) from the rubber roll.

In the case of using photolithography, for example, the post electrode 6 can be formed by forming a metal layer (for example, a copper layer) on the workpiece and patterning the metal layer.

It is also preferable to perform baking after forming the post electrode 6.

Next, as shown in FIG. 2C, an insulating layer 4 is formed on the lower electrode 3. The insulating layer 4 is formed so as not to completely cover the post electrode 6. That is, the insulating layer 4 is formed so that at least a part of the post electrode 6 is exposed. As shown in the figure, it is particularly preferable to form the insulating layer 4 so that the upper portion of the post electrode 6 is exposed.

The insulating layer 4 can be formed, for example, by applying or printing ink containing an insulating material. As a specific method of application or printing, for example, the method described for the lower electrode 3 can be used.

Further, as a particularly preferable method for forming an insulating layer, an ink is applied to a roll to form an application surface, and then the relief plate is pressed against the application surface of the roll to transfer the ink to the convex portion of the relief plate. Examples thereof include a method in which ink is partially removed from the application surface, and then the ink remaining on the application surface is transferred to a workpiece.

As the insulating material, for example, an inorganic material such as SiO ₂ or SiN, or an organic material such as polyvinyl phenol resin, polyvinyl alcohol resin, polyimide resin, or novolac resin can be used. The ink can contain such an insulating material dissolved or dispersed in an organic solvent and / or water. Further, the ink can further contain a curing agent, a crosslinking aid and the like as appropriate. As an example of a preferable ink, an ink containing a polyvinyl phenol resin, an epoxy resin, and a crosslinking aid in an organic solvent capable of dissolving the polyvinyl phenol resin can be given.

Also, the insulating layer 4 can be formed by, for example, sputtering, vapor deposition, CVD, or the like.

Furthermore, the insulating layer 4 may have a laminated structure formed by using a plurality of insulating materials.

It is also preferable to perform baking after forming the insulating layer 4.

Next, as shown in FIG. 2D, a conductive ink layer 8 made of a conductive ink is applied so as to come into contact with the post electrode 6. The conductive ink layer 8 is a layer that forms the conductive layer 7 by drying or by drying and baking.

As the conductive ink, an ink containing a conductive material described for the method of forming the lower electrode 3 can be used.

The conductive ink used for forming the conductive ink layer 8 can be in good contact with the surface of the post electrode 6 due to the fluidity because it is an ink. Therefore, the conductive layer 7 formed from the conductive ink layer 8 has good contact with the post electrode 6 and can improve the stability of electrical connection.

From the viewpoint of imparting suitable fluidity to the conductive ink, the viscosity of the conductive ink is preferably in the range of 0.5 mPa · s to 1000 mPa · s. The viscosity here is a value measured at 25 ° C.

As a method for forming the conductive ink layer 8 by applying conductive ink, for example, the method described for the lower electrode 3 can be used, but it is particularly preferable to use a printing method, and among these, ink jet printing is preferable. When ink jet printing is used, the viscosity of the ink is preferably in the range of 1 mPa · s to 20 mPa · s. The viscosity here is measured at the temperature at which the ink is ejected.

It is possible to carry out baking after forming the conductive ink layer 8, but preferably the following upper electrode 5 is formed without baking. That is, it is particularly preferable to fire the conductive ink layer 8 and the upper electrode 5 at the same time.

Next, as shown in FIG. 2E, the upper electrode 5 is formed on the insulating layer 4. The upper electrode 5 is formed so as to be in contact with the conductive ink layer 8.

The upper electrode 5 can be formed using, for example, the method described for the lower electrode 3, but is particularly preferably formed by transfer printing.

Transfer printing is a method in which an electrode film formed in advance is transferred to a workpiece and printed, and examples thereof include offset printing, flexographic printing, and gravure printing. In transfer printing, an electrode film that has been dried in advance is preferably used as the electrode film transferred to the workpiece. This is because the flowability can be reduced and the printing accuracy can be improved by proceeding with drying. Specifically, when the drying proceeds, for example, semi-drying or full drying can be performed. In the conventional method, the electrode film with reduced fluidity has a point contact with the post electrode 6 and lacks reliability of conduction, but according to the present invention, such an electrode film is not suitable. However, the reliability of conduction can be ensured. Therefore, by forming the upper electrode by transfer printing, it is possible to achieve both improvement in printing accuracy and reliability of conduction.

Baking is preferably performed after the upper electrode 5 is formed, whereby the conductive ink layer 8 made of conductive ink becomes a conductive layer 7 as shown in FIG. By firing the upper electrode 5 together with the conductive ink layer 8, the electrical connection between the fired conductive layer 7 and the upper electrode 5 can be further stabilized. Since the conductive layer 7 and the upper electrode 5 are fired at the same time, a conductive material constituting the conductive layer 7 and a conductive material constituting the upper electrode 5 are formed at the joint between the conductive layer 7 and the upper electrode 5. A region in which is mixed is formed. Thereby, as described above, the electrical connection between the conductive layer 7 and the upper electrode 5 can be further stabilized.

In this way, the wiring laminated structure 1 shown in FIG. 1 can be formed.

According to the present invention, it is possible to prevent an increase in the resistance value between the electrodes due to the residue derived from the ink component. That is, in the ink, various additives such as a fluorosurfactant can be blended in order to adjust the ink physical properties such as viscosity and surface tension to obtain printability. In particular, in an ink containing a conductive material, an organic substance such as a dispersant can be blended in order to maintain the dispersibility of the metal particles. In the conventional method, these compounding components can become a residue after firing and cause the resistance value between the electrodes to increase, but in the present invention, the electrical connection can be stabilized by the interposition of the conductive layer 7. Thus, it is possible to sufficiently reduce the influence of the residue and prevent an increase in the resistance value between the electrodes.

Moreover, according to the present invention, it is possible to prevent an increase in the interelectrode resistance value derived from the insulating layer 4. That is, it is preferable to form the insulating layer 4 after the post electrode 6 is formed. However, in the conventional method, the post-patterning accuracy of the insulating layer 4 and the residue generated during the formation of the insulating layer 4 may cause the post. The area of the conductive portion on the surface of the electrode 6 becomes small, or the resistance value on the surface of the post electrode 6 becomes high, which easily leads to poor connection. On the other hand, in the present invention, since the electrical connection is stabilized by the interposition of the conductive layer 7, the influence derived from the insulating layer 4 can be sufficiently reduced to prevent an increase in the resistance value between the electrodes. it can.

Furthermore, in the conventional technique, the surface of the post electrode after firing is porous and has many irregularities, so that the contact with the upper electrode becomes a point contact, which may easily cause a connection failure. According to the invention, even in such a case, the electrical connection can be secured stably.

Further, in the conventional technique, when a voltage is applied between the upper and lower electrodes, a phenomenon in which a current hardly flows in a weak voltage region may be observed, but according to the present invention, the voltage region is weak. However, since a current value proportional to the voltage is observed, the reliability of the electrical connection can be improved from this viewpoint.

In the above description, the case where the conductive ink for forming the conductive layer is applied before the upper electrode is formed is shown, but the present invention is not limited to this.

For example, it is also preferable to apply conductive ink for forming a conductive layer after forming the upper electrode. In this case, for example, when the conductive ink is applied, the conductive ink can be applied through the opening by providing an opening for exposing the post electrode in the upper electrode in advance.

FIG. 3 is a cross-sectional view conceptually illustrating another example of a wiring laminated structure.

In the illustrated example, an opening 51 is provided in the upper electrode 5 of the wiring laminated structure 1.

The wiring laminated structure 1 includes a conductive layer 7 formed of a conductive ink applied through the opening 51 of the upper electrode 5.

FIG. 4 is a cross-sectional view conceptually illustrating an example of a method for forming the wiring laminated structure shown in FIG.

As shown in FIG. 4A, the lower electrode 3 is formed on the substrate 2.

Next, as shown in FIG. 4B, a post electrode 6 is formed on the lower electrode 3.

Next, as shown in FIG. 4C, an insulating layer 4 is formed on the lower electrode 3. The insulating layer 4 is formed so as not to completely cover the post electrode 6. That is, the insulating layer 4 is formed so that at least a part of the post electrode 6 is exposed.

Next, an upper electrode 5 is formed on the insulating layer 4 as shown in FIG. The upper electrode 5 is provided with an opening 51 for exposing the post electrode 6.

The method of forming the upper electrode 5 having such an opening 51 is not particularly limited, but a method of transferring an electrode film that has been previously patterned into a shape having the opening 51 is particularly suitable.

At this stage, the upper electrode 5 can be fired, but preferably, the following conductive ink layer 8 is formed without firing. It is particularly preferable to fire the conductive ink layer 8 and the upper electrode 5 at the same time.

Next, as shown in FIG. 4E, a conductive ink layer 8 made of a conductive ink is applied so as to come into contact with the post electrode 6. The conductive ink can be applied through the opening 51 of the upper electrode 5. The conductive ink layer 8 is formed in contact with the upper electrode 5.

After the conductive ink layer 8 is formed, firing is performed, so that the conductive ink layer 8 made of the conductive ink becomes the conductive layer 7 as shown in FIG.

In this way, the wiring laminated structure 1 shown in FIG. 3 can be formed.

Next, the case where the ink jet method is used for applying the conductive ink for forming the conductive layer will be described in more detail.

FIG. 5 is a cross-sectional view conceptually illustrating still another example of the wiring laminated structure.

In the illustrated example, an opening 51 is provided in the upper electrode 5 of the wiring laminated structure 1 as in the example of FIG. The opening 51 in the example of FIG. 5 is formed larger than the opening 51 in the example of FIG. Specifically, the opening 51 in the example of FIG. 3 has an opening area approximately equal to the diameter of the post electrode 6, whereas the opening 51 in the example of FIG. Has a wide opening area.

The wiring laminated structure 1 includes a conductive layer 7 formed of a conductive ink applied through the opening 51 of the upper electrode 5. The conductive layer 7 is formed of an aggregate of conductive ink droplets that have landed at different landing positions using the inkjet head method.

FIG. 6 is a cross-sectional view conceptually illustrating an example of a method for forming the wiring laminated structure shown in FIG.

As shown in FIG. 6A, the lower electrode 3 is formed on the substrate 2.

Next, as shown in FIG. 6B, a post electrode 6 is formed on the lower electrode 3.

Next, as shown in FIG. 6C, an insulating layer 4 is formed on the lower electrode 3. The insulating layer 4 is formed so as not to completely cover the post electrode 6. That is, the insulating layer 4 is formed so that at least a part of the post electrode 6 is exposed.

Next, as shown in FIG. 6D, the upper electrode 5 is formed on the insulating layer 4. The upper electrode 5 is provided with an opening 51 for exposing the post electrode 6. The opening 51 has an opening area wider than the diameter of the post electrode 6. Since the opening 51 has a wide opening area, the post electrode 6 can be more reliably exposed from the opening 51. For example, the post electrode 6 can be exposed from the opening 51 even if a slight shift occurs between the position of the opening 51 of the upper electrode 5 and the post electrode 6 when the upper electrode 5 is formed.

Next, as shown in FIG. 6E, a conductive ink layer 8 made of a conductive ink is applied so as to come into contact with the post electrode 6. The conductive ink can be applied through the opening 51 of the upper electrode 5. The conductive ink layer 8 is formed of an aggregate of conductive ink droplets that have landed at different landing positions using the inkjet head method. The conductive ink layer 8 is formed in contact with the upper electrode 5.

After the conductive ink layer 8 is formed, baking is performed, so that the conductive ink layer 8 made of the conductive ink becomes the conductive layer 7 as shown in FIG.

In this way, the wiring laminated structure 1 shown in FIG. 5 can be formed.

In the above description, the case where the contact hole 41 of the insulating layer 4 is blocked by the post electrode 6, that is, the case where the post electrode 6 is formed in the entire contact hole 41 of the insulating layer 4 is shown. However, the present invention is not limited to this.

For example, as shown in FIG. 7, it is also preferable that the post electrode 6 is formed in a part of the contact hole 41 of the insulating layer 4. In this case, as shown in FIG. 7, it is also preferable that the conductive layer 7 enters a region other than the region where the post electrode 6 is formed in the contact hole 41 of the insulating layer 4.

FIG. 8 is a cross-sectional view conceptually illustrating an example of a method for forming the wiring laminated structure shown in FIG.

As shown in FIG. 8A, the lower electrode 3 is formed on the substrate 2.

Next, as shown in FIG. 8B, a post electrode 6 is formed on the lower electrode 3.

Next, as shown in FIG. 8C, an insulating layer 4 is formed on the lower electrode 3. The insulating layer 4 has a contact hole 41 having a diameter larger than that of the post electrode 6 so that the post electrode 6 is formed in a part of the contact hole 41 of the insulating layer 4.

Next, as shown in FIG. 8D, the upper electrode 5 is formed on the insulating layer 4. The upper electrode 5 is provided with an opening 51 for exposing the post electrode 6.

Next, as shown in FIG. 8 (e), a conductive ink layer 8 made of a conductive ink is applied so as to come into contact with the post electrode 6. The conductive ink can be applied through the opening 51 of the upper electrode 5. The conductive ink enters the region other than the region where the post electrode 6 is formed in the contact hole 41 of the insulating layer 4 to form the conductive ink layer 8. The conductive ink layer 8 is formed so as to be in contact with the upper electrode 5.

In this way, the wiring laminated structure 1 shown in FIG. 7 can be formed.

In the above description, the case where the step of applying the conductive ink so as to come into contact with the post electrode is mainly provided after the step of forming the insulating layer, but the present invention is not limited to this. As another aspect of the method for forming the wiring laminated structure, a step of forming an insulating layer may be provided after the step of applying the conductive ink so as to be in contact with the post electrode.

Another aspect of the method for forming the wiring laminated structure will be described in detail with reference to FIG.

FIG. 9 is a cross-sectional view conceptually illustrating another aspect of the method for forming the wiring laminated structure.

Also in this embodiment, first, the lower electrode 3 is formed on the substrate 2 as shown in FIG. *

Next, as shown in FIG. 9B, a post electrode 6 is formed on the lower electrode 3. It is also preferable to perform baking after forming the post electrode 6.

Next, as shown in FIG. 9C, a conductive ink layer 8 made of conductive ink is applied so as to come into contact with the post electrode 6. The conductive ink layer 8 is a layer that forms the conductive layer 7 by drying or by drying and baking.

In this aspect, since the conductive ink is applied before the formation of the insulating layer 4, the conductive ink can be more reliably applied to the post electrode 6 in a suitably exposed state. Further, it is easy to form the conductive ink layer 8 so as to be in contact with a wide range of the surface of the post electrode 6, and an effect of further stabilizing the electrical connection can be obtained.

Next, as shown in FIG. 9D, an insulating layer 4 is formed on the lower electrode 3. The insulating layer 4 is formed so as not to completely cover the conductive ink layer 8 made of conductive ink. That is, the insulating layer 4 is formed so that at least a part of the conductive ink constituting the conductive ink layer 8 is exposed. As shown in the drawing, it is particularly preferable to form the insulating layer 4 so that the conductive ink layer 8 covering the upper portion of the post electrode 6 is exposed.

Next, as shown in FIG. 9E, the upper electrode 5 is formed on the insulating layer 4. The upper electrode 5 is formed so as to be in contact with the conductive ink layer 8.

Baking is preferably performed after the upper electrode 5 is formed, whereby the conductive ink layer 8 made of conductive ink becomes the conductive layer 7 as shown in FIG. By firing the upper electrode 5 together with the conductive ink layer 8, the electrical connection between the fired conductive layer 7 and the upper electrode 5 can be further stabilized.

In this way, the wiring laminated structure 1 can be formed.

In the embodiment described above, a liquid that does not contain a conductive material may be applied in contact with the post electrode 6 instead of the conductive ink. Examples of the liquid not containing the conductive material include water and organic solvents. In this case, the conductive material which comprises at least a part of the surface of the post electrode 6 is eluted or dispersed by the liquid not containing the conductive material, and the conductive ink composed of the liquid and the conductive material is used as the post electrode 6. Can be produced on the surface. Thereby, the conductive ink layer 8 similar to that shown in FIG. 9C can be formed. That is, the conductive ink layer 8 can be formed by wetting at least part of the surface of the post electrode 6. The liquid not containing the conductive material may be applied by a printing method or the like, but may be applied by exposing the post electrode 6 under the vapor of the liquid.

Further, as another aspect, the post electrode precursor can be obtained without completely baking the post electrode by adjusting the conditions for drying and baking the conductive ink applied to form the post electrode. It is also preferable to form By using such a post electrode precursor, the surface layer of the post electrode precursor can function as the conductive ink layer described above.

Specifically, first, a conductive ink for forming a post electrode is applied on the lower electrode. As a method for applying the conductive ink, per se known printing methods such as the above-described screen printing, offset printing, flexographic printing, gravure printing, and ink jet printing can be used, and ink jet printing is particularly preferable.

Next, a part of the conductive ink is dried to form a post electrode precursor in which the conductive ink remains on at least a part of the surface. Here, “drying a part of the conductive ink” means that the ink solvent derived from the conductive ink is not completely dried, and as described above, when the conductive ink is dried and baked. This can be achieved by adjusting the conditions. Further, “the conductive ink remains on at least part of the surface” means that the ink solvent derived from the conductive ink remains on at least part of the surface. A conductive ink layer is formed by the portion where the ink solvent remains.

Next, an insulating layer is formed on the lower electrode so as to expose at least a part of the conductive ink (conductive ink layer) on the surface of the post electrode precursor.

Next, an upper electrode is formed on the insulating layer so as to come into contact with the conductive ink (conductive ink layer) on the surface of the post electrode precursor.

The post electrode precursor can be made into a post electrode by firing the conductive ink after forming the upper electrode. The upper electrode is also baked simultaneously with the conductive ink remaining on the surface of the post electrode precursor, whereby the electrical connection between the baked post electrode and the upper electrode can be further stabilized.

By using the post electrode precursor as described above, the process for manufacturing the wiring laminated structure can be shortened. Furthermore, since an interface is unlikely to be generated between the post electrode and the conductive ink layer, an effect of further stabilizing the electrical connection can be obtained.

The substrate 2 is not particularly limited, and an insulating material can be preferably applied, and a known material can be appropriately used depending on the purpose. For example, in addition to relatively hard and high heat resistant substrates such as glass substrates, ceramic substrates, metal substrates (eg metal thin film substrates), paper phenol substrates, paper epoxy substrates, nanocellulose fiber paper, It may be a substrate made of a mixture of two kinds such as a glass composite substrate and a glass epoxy substrate, or may be a resin substrate. Examples of the resin of the resin base material include polyimide, polyamide, polyethylene terephthalate, polyethylene naphthalate, and polyethersulfone. The substrate 2 may have a single layer structure or a multilayer structure, and an insulating coated conductive material or the like can also be used.

In particular, the substrate 2 is preferably a flexible substrate (also referred to as a flexible substrate) such as a film or the like from the viewpoint of remarkably exhibiting the effects of the present invention. Even if deformation based on the flexibility of the base material 2 occurs, an electrical interlayer connection between the lower electrode 3 and the upper electrode 5 is ensured, and an effect of obtaining reliable conduction is obtained. Because. In the conventional technique, when a resin film derived from an ink component is formed on the surface of the post electrode or the upper electrode, the resistance value is likely to increase when deformation based on the flexibility of the base material occurs. However, in the present invention, reliable conduction can be maintained even in such a case.

In the case where the lower electrode has sufficient strength, the use of the base material may be omitted as appropriate.

The use of the wiring laminated structure according to the present invention is not particularly limited, and is suitably used when a lower electrode and an upper electrode laminated via an insulating layer are connected via a contact hole provided in the insulating layer. be able to. Particularly preferred applications include flexible printed circuit boards, printed circuit boards (also simply referred to as printed circuit boards), thin film transistors, integrated circuits, and the like.

FIG. 10 is a cross-sectional view conceptually illustrating an example of a thin film transistor provided with a wiring laminated structure.

The thin film transistor shown in FIG. 10 includes a gate electrode 9 on a base material 2, an insulating layer 10 on the gate electrode 9, and a source electrode 11 and a lower electrode 3 that is a drain electrode on the insulating layer 10. . That is, here, the drain electrode corresponds to the lower electrode 3. Reference numeral 12 denotes a semiconductor layer formed between the source electrode 11 and the drain electrode (lower electrode 3).

The insulating layer 4 is provided on the drain electrode (lower electrode 3), and the upper electrode 5 is provided on the insulating layer 4.

In the contact hole 41 of the insulating layer 4, a post electrode 6 for obtaining conduction between the drain electrode (lower electrode 3) and the upper electrode 5 is provided.

Thereby, the electrical interlayer connection between the drain electrode (lower electrode 3) and the upper electrode 5 is ensured, and an effect of obtaining reliable conduction is obtained.

In the above description, the configuration described for one aspect can be appropriately applied to other aspects.

1: Wiring laminated structure 2: Base material 3: Lower electrode 4: Insulating layer 41: Contact hole 5: Upper electrode 51: Opening 6: Post electrode 7: Conductive layer 8: Conductive ink layer

Claims

A lower electrode, an insulating layer provided on the lower electrode, and an upper electrode provided on the insulating layer,
A contact hole is provided in the insulating layer, and a post electrode for obtaining conduction between the lower electrode and the upper electrode is provided in the contact hole,
A wiring laminated structure in which a conductive layer formed of conductive ink is interposed between the post electrode and the upper electrode.
The wiring laminated structure according to claim 1, wherein the conductive layer and the upper electrode are fired simultaneously.
The wiring laminated structure according to claim 1 or 2, wherein the lower electrode is supported by a base material.
The wiring laminated structure according to claim 3, wherein the base material is a film.
Forming a post electrode on the lower electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the post electrode;
Applying a conductive ink for forming a conductive layer so as to be in contact with the post electrode;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
A method for forming a wiring laminated structure having:
Forming a post electrode on the lower electrode;
Applying a conductive ink for forming a conductive layer so as to be in contact with the post electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the conductive ink;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
A method for forming a wiring laminated structure having:
Forming a post electrode on the lower electrode;
Forming an insulating layer on the lower electrode so as to expose at least part of the post electrode;
Forming an upper electrode having an opening exposing the post electrode on the insulating layer;
Applying a conductive ink for forming a conductive layer so as to be in contact with the upper electrode and the post electrode through the opening of the upper electrode;
A method for forming a wiring laminated structure having:
The method for forming a wiring laminated structure according to claim 7, wherein the upper electrode is formed by transferring an electrode film that has been previously patterned into a shape having an opening.
9. The method for forming a wiring laminated structure according to claim 5, wherein the post electrode is formed by any one of screen printing, gravure printing, flexographic printing, and inkjet printing.
10. The method for forming a wiring laminated structure according to claim 5, wherein the conductive ink is applied by ink jet printing.
The method for forming a wiring laminated structure according to any one of claims 5 to 10, wherein the upper electrode is formed by transfer printing.
12. The method for forming a wiring laminated structure according to claim 5, wherein the conductive ink is baked after forming the upper electrode.
The method for forming a wiring laminated structure according to any one of claims 5 to 12, wherein the lower electrode is supported by a base material.
14. The method for forming a wiring laminated structure according to claim 13, wherein the substrate is a film.
Applying a conductive ink to form a post electrode on the lower electrode;
Forming a post electrode precursor in which the conductive ink remains on at least a part of the surface by drying a part of the conductive ink; and
Forming an insulating layer on the lower electrode so as to expose at least part of the conductive ink;
Forming an upper electrode on the insulating layer in contact with the conductive ink;
Baking the conductive ink after forming the upper electrode to form the post electrode precursor as a post electrode;
A method for forming a wiring laminated structure having:
The method for forming a wiring laminated structure according to claim 15, wherein the conductive ink for forming the post electrode is applied by ink jet printing.