WO2010010609A1

WO2010010609A1 - Method for forming contact hole, and circuit board

Info

Publication number: WO2010010609A1
Application number: PCT/JP2008/063138
Authority: WO
Inventors: 悟大田
Original assignee: パイオニア株式会社
Priority date: 2008-07-22
Filing date: 2008-07-22
Publication date: 2010-01-28

Abstract

[PROBLEMS] To form a wiring of a contact hole structure by a simple wet process. [MEANS FOR SOLVING PROBLEMS] On a base surface (2) on which first conductive members (31, 41) are formed, a photosensitive resin obtained by mixing a liquid repellent photosensitive resin or liquid repellent component containing a conductive material is applied to generate a coating film (71). The coating film (71) is patterned by photolithography to form a conducting portion (72) of a contact hole. Thereafter, on the base surface on which the conducting portion (72) of the contact hole and the first conductive members (31, 41) are formed, an insulating material is applied to form an insulating film (8). Finally, second conductive members (32, 33, 42, 43) are formed on the insulating film (8).

Description

Contact hole forming method and circuit board

The present invention relates to a contact hole forming method and a circuit board.

A contact hole is one of the wirings connecting elements such as transistors and capacitors formed on a circuit board. A conventional typical method for forming a contact hole is a method as disclosed in Patent Document 1. That is, as shown in FIG. 4A, the insulating film 11 is formed on the substrate 1 on which the metal thin film to be the lower electrode 10 is formed, and the resist film 12 is formed on the insulating film 11. Then, as shown in FIG. 4B, an opening for forming a contact hole is formed in the resist film 12 by a photolithography technique, and reactive gas etching, reactive ion etching, or the like is performed using the resist film 12 as a mask. By performing etching or ashing with oxygen plasma, the insulating film 11 is selectively removed to form the holes 13. Subsequently, as shown in FIG. 4C, a conductive portion 14 is formed in the hole by a vacuum process such as sputtering, the resist film 12 is removed, and then a metal thin film that becomes the upper electrode 15 is formed on the insulating film 11. A contact hole is formed by forming.

In addition, the conductive material is injected into the hole 13 formed by etching or ashing in place of the above-described vacuum process, such as a method of plating after forming a conductive polymer, or a method of pouring the conductive polymer into the hole 13. It can also be formed by a wet process (see, for example, Patent Document 2).

However, since the conventional method includes an etching process and an ashing process, there is a problem that an expensive apparatus is required and a large number of substrates cannot be processed at a time. In addition, these devices consume a large amount of power, and it is difficult to say that they are desirable steps in the recent call for CO ₂ reduction.

Furthermore, in the conventional method including the dry process such as etching and ashing as described above, there is a problem that the advantage in the manufacturing aspect of the organic transistor is offset when the circuit substrate is formed using the organic transistor which has been attracting attention in recent years. is there. That is, an organic transistor uses an organic material as a material for an insulating film (gate insulating film) and a semiconductor layer, and thus has an advantage that a circuit can be formed by a simple method such as a wet process. If it is included, the advantages of the organic transistor that can be manufactured only by the wet process are offset.

In addition, conventionally, a method of forming the hole 13 without performing etching or ashing has been studied. Specifically, this is a method of forming a hole 13 in the insulating film 11 by a photolithography technique using a photosensitive material for the insulating film 11. However, in this case, an undesired component such as a photoinitiator or the like as a gate insulating film of the transistor is included, and thus desired insulating characteristics may not be obtained.

JP-A-2-26025 JP 2005-203667 A

The above-mentioned problem is given as an example of the problem to be solved by the present invention. In view of the above, an object of the present invention is to provide a contact hole forming method capable of forming a contact hole structure wiring by a simple wet process, and to provide a circuit board having a contact hole.

Another object of the present invention is to overcome the conventional common sense of forming a hole in an insulating film and injecting a conductive material, and to form a novel contact hole forming method in which a conductive portion of a contact hole is formed first, and An example is to provide a circuit board having contact holes.

Another object of the present invention is to provide a contact hole forming method suitable for a circuit board having an organic transistor as an element, and a circuit board having a contact hole connected to the organic transistor, as an example. .

The contact hole forming method according to the present invention is a contact hole forming method for connecting a first conductive member and a second conductive member arranged via an insulating film as described in claim 1. Applying a liquid-repellent photosensitive resin containing a conductive material or a photosensitive resin mixed with a liquid-repellent component to a base surface on which the first conductive member is formed, and forming a coating film; Patterning the coating film by photolithography to form a conductive portion of a contact hole made of a liquid repellent photosensitive resin containing the conductive material or a photosensitive resin mixed with a liquid repellent component; and the contact Forming an insulating film by applying an insulating material to a ground surface on which the conductive portion of the hole and the first conductive member are formed; and forming a second conductive member on the insulating film; Special features, including To.

A circuit board according to the present invention is a circuit board including a contact hole for connecting a first conductive member and a second conductive member arranged via an insulating film as described in claim 12. The conductive portion of the contact hole is formed of a liquid repellent photosensitive resin containing a conductive material or a photosensitive resin mixed with a liquid repellent component.

As a circuit board according to a preferred embodiment of the present invention, a circuit board for an organic EL display device is shown. It is a circuit diagram of the circuit board. FIG. 6 is a process diagram in which contact holes are formed according to a preferred embodiment of the present invention. It is a figure which shows the formation method of the contact hole by a conventional method.

Explanation of symbols

3 Organic transistor (Tr1)
31 Gate electrode 32 Source electrode 33 Drain electrode 4 Organic transistor (Tr2)
41 Gate electrode 42 Source electrode 43 Drain electrode 5 Organic EL element 6 Capacitor 7 Contact hole 72 Conducting portion 8 Insulating film

A preferred embodiment of the contact hole forming method and circuit board according to the present invention will be described in detail with reference to the accompanying drawings. However, the technical scope of the present invention is not limited and interpreted by the embodiments described below.

As an example of the circuit board according to the present embodiment, FIG. 1 and FIG. 2 show a circuit board 2 for an organic EL display device. FIG. 1 shows a plan view and a side view (portion of an organic transistor) of the circuit board 2, and FIG. 2 shows a circuit diagram.

As shown in FIG. 1, the circuit board 2 according to the present embodiment includes two organic transistors (Tr1) 3 and (Tr2) 4 (for example, organic TFT) and an organic EL (electroluminescence) element 5 (light emitting element) ( For example, an OLED or the like) and a charge holding capacitor (Cap) 6 (for example, a storage capacitor or the like) are formed to form a dot of the display device. In an actual apparatus, a display area is configured by arranging a large number of dots in a matrix. The organic transistor 3 is a switching transistor, and the organic transistor 4 is a driving transistor. These elements formed on the circuit board 2 form a circuit as shown in FIG. 2 and are configured to actively drive the organic EL element 5. Note that the arrangement of each element shown in FIG. 1 is described as an example, and is not limited to this arrangement.

As shown in FIG. 2, the gate electrode 31 of the switching organic transistor 3 is connected to the scan line (Vscan), and the source electrode 32 is connected to the data line (Vdata). Further, the drain electrode 33 is connected to the gate electrode 41 of the driving organic transistor 4 and to one terminal of the capacitor 6 of the capacitance line (Vcap).

The source electrode 42 of the driving organic transistor 4 is connected to the low potential side power supply line (Vss). Furthermore, the anode terminal of the organic EL element 5 is connected to the drain electrode 43 of the organic transistor 4 for driving. Note that

reference numerals

34 and 44 in FIG. 1 denote organic semiconductor layers.

As described above, when forming a circuit for actively driving the organic EL element 5 using the two

organic transistors

3 and 4, it is necessary to ensure conduction between the

organic transistors

3 and 4 and the capacitor 6. Therefore, a contact hole 7 as shown in FIG. 1B is formed in the insulating film (gate insulating film) 8.

In this embodiment, a liquid repellent photosensitive resin containing a conductive material or a mixture of a liquid repellent component mixed with a photosensitive resin containing a conductive material is used as a material for forming the conductive portion of the contact hole 7. And the said photosensitive resin is apply | coated on the board | substrate 2, a coating film is formed, and the conductive part of a desired magnitude | size is formed in a desired position by patterning by the photolithographic method. Thus, after forming the conductive portion by the wet process, the insulating film 8 is also formed by the wet process, thereby realizing the formation of the contact hole structure in the reverse order. .

As the conductive material, any one of a conductive nanotube, metal fine particles, and a conductive polymer, or a mixture of two or more types can be used.

The conductive nanotube only needs to have conductivity, and the size and type thereof are not particularly limited. As the conductive nanotube, a carbon nanotube is preferable. However, it is not limited to carbon nanotubes, and noble metal nanotubes such as gold nanotubes and platinum nanotubes can be used. Furthermore, the structure may be either a single layer structure or a multilayer structure, and may be either a structure with a closed tip or an open structure. Furthermore, either a conductor or a semiconductor may be used. However, in order to ensure conduction, it is preferable to use a material having a diameter of 0.5 to 100 nm and a length of 0.05 to 1 μm. If the amount of the conductive nanotube is too small with respect to the photosensitive resin, sufficient conduction may not be obtained. Conversely, if the amount of conductive nanotubes is too large, patterning may not be possible by photolithography. Accordingly, a preferable blending ratio of the conductive nanotubes is 1 to 50% by mass, preferably 1 to 25% by mass. Since the nanotubes have an elongated shape, there is an advantage that the contact rate between the nanotubes in the photosensitive resin is increased and it is easy to ensure conduction.

Further, the type of metal fine particles is not particularly limited as long as it is conductive metal fine particles. Preferable examples include fine particles of any one of Ag, Au, Cu, Cr, Fe, Zn, Al, Pt, ZuO, SnO, IZO, and ITO, or a mixture of two or more fine particles. The size of the metal fine particles is not particularly limited, but is preferably fine to ensure conduction, and it is preferable to use nanoparticles or microparticles. More preferred are fine particles having a particle size of 1 to 100 nm. In addition, for the same reason as that of the conductive nanotube, a preferable blending ratio of metal fine particles that can provide sufficient conduction and can be patterned can be 50 to 90% by mass.

The type of the conductive polymer is not particularly limited as long as it is a conductive polymer. Preferred conductive polymers include conjugated polymer compounds such as PEDOT / PSS, polyacetylene, polyparaphenylene, polyaniline, polythiophene, and polyparaphenylene vinylene. Further, a preferable blending ratio of the conductive polymer can be 50 to 90% by mass.

As the photosensitive resin containing (dispersing) the above-described conductive material, a photoresist can be cited as an example. The photosensitive property may be either positive or negative, and a chemically amplified resist can also be used. The resin is not particularly limited as long as it can form a pattern by being exposed to light. Preferable examples include acrylic resin, epoxy resin, polyimide resin and the like. Furthermore, although detailed reason is mentioned later, it is preferable that the photosensitive resin used for this embodiment has a liquid-repellent property. In this case, it is preferable to use a liquid repellent photosensitive resin having a liquid repellent molecule such as a fluorine component in the molecular structure of the photosensitive resin, or a photosensitive resin mixed with a liquid repellent component such as a fluorine component.

As the conductive material, the photosensitive resin, and the liquid repellent material, commercially available materials may be used, respectively, or they may be manufactured using a known manufacturing method. In the present embodiment, a liquid repellent photosensitive material containing a conductive material is mixed by mixing a large number of conductive materials in a solvent in which a liquid repellent photosensitive resin or a photosensitive resin mixed with a liquid repellent component is dissolved. You may make it prepare the mixture which mixed the liquid repellent component with resin or the photosensitive resin containing an electroconductive material. Of course, it may be prepared by other methods.

The type of the solvent is not particularly limited, and an example is propylene glycol monomethyl ether acetate (PGMEA). In the present embodiment, the conductive material and the photosensitive resin, and in the case of further addition, the liquid repellent component may be used as a main component, and the addition of other components is not limited. As other additive components, in particular, when metal fine particles are used, a dispersant for suppressing aggregation of the fine particles can be added. One example thereof is modifying the surface of the fine particles with a thiol compound or a silane coupling agent.

In addition, the material of the insulating film used in this embodiment may be formed by a wet process such as a coating method, and any insulating material can be used as long as this condition is satisfied. In the case of forming a gate insulating film of an organic transistor, preferred examples include an aqueous solution containing polyvinyl alcohol (PVA), a PGMEA solution of polyvinyl phenol, and the like.

Subsequently, a process of forming a contact hole according to the present embodiment will be described with reference to FIG. FIG. 3 schematically shows a cross section of the substrate in the main process.

First, a lower electrode is formed as a first conductive member on the substrate 2. In the example shown in FIG. 3A, the gate electrodes (31, 41) of the

organic transistors

3 and 4 are formed. Further, although not shown, the lower electrode, the scan line, and the capacitance line of the capacitor 6 can be formed in this step. Examples of the electrode forming method include a sputtering method and an electroless plating method. However, it is not limited to this, and any film forming method may be used. Also, the electrode material is not particularly limited, but as an example, Pt, Au, W, Ru, Ir, Al, Sc, Ti, V, Mn, Fe, Co, Ni, Zn, Ga, Y, Zr Nb, Mo, Tc, Rh, Pd, Ag, Cd, Ln, Sn, Ta, Re, Os, Tl, Pb, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb, Lu and other metal or combinations thereof, organic conductive materials including conjugated polymer compounds such as metal oxides such as ITO and IZO, polyanilines, polythiophenes and polypyrroles be able to. Examples of the substrate 2 include a glass substrate and a plastic substrate.

Subsequently, as shown in FIG. 3B, a liquid-repellent photosensitive material containing a conductive material on the substrate 2 on which the gate electrodes (31, 41) are formed (that is, a base surface on which a conductive portion is formed). A mixture of a resin or a photosensitive resin containing a conductive material mixed with a liquid repellent component is applied and dried to form a coating film 71. Next, a known resist is applied on the coating film 71 and dried to form a resist film 9. An example of the coating method is a spin coating method. However, it is not limited to this, and any coating method may be used. Further, by exposing and developing through a photomask (not shown), an opening 91 of the resist film 9 is formed at a position where a conductive portion of the contact hole is to be formed. In addition to exposure through a photomask, a known photolithography method such as electron beam drawing can be employed.

Subsequently, as shown in FIG. 3C, the resist film 9 in which the opening 91 is formed is used as a mask to irradiate light to the lower layer film 71 and develop the conductive film at a position corresponding to the opening 91. A conductive portion 72 made of a liquid repellent photosensitive resin containing a conductive material or a mixture of a liquid repellent component mixed with a photosensitive resin containing a conductive material is formed. When the conductive portion 72 is formed in this way, for example, a baking process is performed by heating at a temperature corresponding to the type of resin, and the resin of the conductive portion 72 is cured. The film 71 can be irradiated with light by using a light source such as ultra-high pressure mercury as an example.

Subsequently, as shown in FIG. 3D, on the substrate 2 on which the conductive portion 71 and the gate electrodes (31, 41) are formed (that is, the ground surface on which the conductive portion and the first conductive member are formed). Then, an insulating material (for example, 10% aqueous solution of PVA) is applied and dried to form the insulating film 8. The insulating film 8 can be a dielectric of the capacitor 6 as well as the gate insulating films of the

transistors

3 and 4. The insulating material is not limited to PVA, and other polymers having insulating properties can also be used. In this embodiment, since the conductive portion having liquid repellency is formed, it is possible to use almost all polymers in addition to the polymer that dissolves in water. Examples of the coating method include spin coating and the like. However, it is not limited to this, and any coating method may be used.

Subsequently, an upper electrode as a second conductive member is formed on the insulating film 8. In the example shown in FIG. 3 (e), the source electrodes (32, 42) and drain electrodes (42, 43) of the

organic transistors

3 and 4; the upper electrode of the capacitor 6 (not shown); the data line and the power line; Wires to be connected are formed in a lump. Examples of the electrode forming method include a sputtering method and an electroless plating method. However, it is not limited to this, and any film forming method may be used. Further, the electrode material is not particularly limited, and the same material as the above-described gate electrode can be used. In the example of FIG. 3, the electrodes and wirings are formed in a lump in order to simplify the process, but each electrode or wiring may be formed in a separate process.

Finally, for the channel portions of the source electrode (32, 42) and the drain electrode (33, 43), for example, poly-3-hexylthiophene (P3HT), poly [9,9-dioctylfluorene-co-bithiophene] An organic semiconductor material such as (F8T2) is applied and dried to form the organic semiconductor layers (34, 44). As an example, the organic semiconductor material may be applied by an inkjet method. At this time, the bank may be formed so as to surround a region where the organic semiconductor material is applied. Although detailed explanation is omitted, the lower electrode, the organic EL layer, and the upper electrode of the organic EL element 5 are sequentially formed at predetermined positions and sealed with an inorganic material. Through such steps, the circuit board 2 for the organic EL display device having the

organic transistors

3 and 4 is formed.

According to the above-described embodiment, the liquid repellent photosensitive resin containing a fine conductive material or the photosensitive resin containing a fine conductive material as a material for forming the conductive portion 72 of the contact hole 7 is liquid repellent. By using the mixture in which the components are mixed to form a coating film 71 on the substrate 2 and patterning by irradiating light, it is possible to form a conductive portion 72 having a desired size at a desired position. Further, after the conductive portion 72 is formed by the wet process as described above, the insulating film 8 is similarly formed by the wet process. Wiring can be formed. In addition, power consumption can be reduced by the amount corresponding to the elimination of the etching and ashing steps, which can contribute to the reduction of CO ₂ emissions.

Furthermore, according to the above-described embodiment, by using a photosensitive resin having a liquid repellent property, even if an insulating material such as a PVA aqueous solution is applied to the substrate 2 on which the conductive portion 72 is formed, the upper surface and the periphery of the conductive portion 72 Can be prevented from being covered with an insulating material. If the upper surface of the conductive portion 72 is covered with an insulating material, an insulating material is interposed between the upper electrode and the conductive material 72, and sufficient conduction may not be obtained. Therefore, in the present embodiment, by using a photosensitive resin having liquid repellency, the upper surface of the conductive portion 72 is prevented from being covered with an insulating material. As a result, it is possible to form a contact hole that ensures conduction more reliably. This eliminates the step of confirming that it is not covered with an insulating material, and the step of removing it when it is covered, thereby enabling a simple process step.

Furthermore, according to the above-described embodiment, only the conductive portion 72 of the contact hole 7 is formed first, and then the insulating film 8 is formed, thereby preventing problems due to thermal contraction of the conductive portion 72 formed by the wet process. It becomes possible. That is, when a hole is formed in the insulating film in accordance with the conventional method and a conductive material is injected into the hole by a wet process to form the conductive portion 72, the conductive portion 72 is thermally shrunk by drying or baking, and the hole is formed in the hole. In some cases, a cavity is formed, or the upper surface of the conductive portion 72 is lower than the surface of the insulating film. However, in the case of this embodiment, only the conductive portion 72 of the contact hole is formed first, and the insulating film 8 is formed after drying and baking, so that the conductive portion 72 is not thermally contracted. Even the amount of shrinkage is slight. As a result, it is possible to ensure conduction with the upper electrode more reliably.

Furthermore, according to the above-described embodiment, the wiring of the contact hole structure can be formed by a series of wet processes. Therefore, this method is applied to the formation of a circuit substrate having an organic transistor, and can be manufactured by a simple method such as a wet process. It is possible to take advantage of the organic transistor fabrication aspect that it is possible. That is, the contact hole forming method according to the present embodiment is suitable for forming a circuit board having an organic transistor.

As another embodiment, when metal nanoparticles are used as the conductive material, the conductive portion 72 is formed by the process shown in FIG. 3C, and then a sintering process is performed to remove the metal fine particles in the conductive portion 72. You may make it sinter. The temperature for sintering varies depending on the type of metal, but it is usually an example that the temperature is about 80% of the melting temperature of the metal. For example, in the case of Ag, the temperature is 200 to 250 ° C. Except for performing the sintering treatment, the other steps can be performed in the same manner as in the above-described embodiment. Thus, by performing the sintering process, it becomes possible to ensure conduction more reliably.

In still another embodiment, after the conductive portion 72 is formed by the process shown in FIG. 3C, UV treatment, or a combination of UV treatment and ozone treatment is performed, so that all or one of the organic substances contained in the conductive portion 72 is obtained. The part may be disassembled and removed. Thus, by performing the decomposition / removal processing of the organic matter, it is possible to increase the contact rate between the conductive materials and to ensure the conduction more reliably. It is more effective to perform the organic substance decomposition / removal process together with the above-described sintering process.

In the description of the above-described embodiment, the circuit board 2 for an organic EL display device as shown in FIG. 1 is taken as an example. However, the circuit board 2 is not limited to this, and a liquid crystal display or electronic paper is used. Not only a circuit board having an organic transistor such as a general circuit board as shown in FIG. That is, the contact hole forming method according to the present embodiment can be applied to all substrates having contact holes.

Furthermore, in the above-described embodiment, an example in which a contact hole structure wiring is formed is described. However, a liquid repellent photosensitive resin containing a conductive material, or a liquid repellent component in a photosensitive resin containing a conductive material. A mixture obtained by mixing can also be used as a wiring material other than contact holes. In this case, it does not necessarily have liquid repellency.

Further, in the example shown in FIG. 1, a top contact type organic transistor is described, but the structure is not limited to this structure. For example, a bottom contact type or top gate type organic transistor may be used. Furthermore, it is not necessarily an organic transistor and may be an inorganic transistor.

Although one embodiment of the present invention has been described above, it will be apparent to those skilled in the art that many modifications and variations can be made without departing from the spirit and scope of the present invention. Included in the technical scope.

A mixture of Ag particles in a fluorine-containing acrylic photoresist was applied by spin coating on a glass substrate on which a transistor electrode and a capacitor electrode pattern were formed. Next, after UV exposure, the unexposed portion was removed and baked at 220 ° C. to form a conductive portion. Thereafter, a polyvinyl alcohol (PVA) 10% aqueous solution was applied to the glass substrate by spin coating as an insulating film material. Since the conducting portion was water-repellent, no PVA remained on the upper surface of the conducting portion. Finally, an electrode was produced by sputtering to ensure conduction between the transistors and form a circuit.

Claims

A method for forming a contact hole for connecting a first conductive member and a second conductive member disposed via an insulating film,
Applying a liquid repellent photosensitive resin containing a conductive material or a photosensitive resin mixed with a liquid repellent component to a base surface on which the first conductive member is formed;
Patterning the coating film by a photolithography method to form a conductive portion of a contact hole made of a liquid repellent photosensitive resin containing the conductive material or a photosensitive resin mixed with a liquid repellent component;
Applying an insulating material to the base surface on which the conductive portion of the contact hole and the first conductive member are formed, and forming an insulating film;
Forming a second conductive member on the insulating film. A method for forming a contact hole.
2. The contact hole forming method according to claim 1, wherein the conductive material includes a conductive nanotube.
2. The contact hole forming method according to claim 1, wherein the conductive material includes metal fine particles.
2. The contact hole forming method according to claim 1, wherein the conductive material includes a conductive polymer.
The method for forming a contact hole according to claim 2, wherein the compounding ratio of the conductive nanotube to the photosensitive resin mixed with the liquid-repellent photosensitive resin or the liquid-repellent component is 1 to 50% by mass.
The method for forming a contact hole according to claim 3, wherein the compounding ratio of the metal fine particles with respect to the liquid repellent photosensitive resin or a photosensitive resin mixed with a liquid repellent component is 50 to 90% by mass.
The contact hole forming method according to claim 4, wherein the compounding ratio of the conductive polymer to the liquid-repellent photosensitive resin or the photosensitive resin mixed with the liquid-repellent component is 50 to 90% by mass. .
The first conductive member and / or the second conductive member are a lower electrode and / or an upper electrode of a transistor, and the insulating film is a gate insulating film of the transistor. The method for forming a contact hole according to any one of the above.
9. The contact hole forming method according to claim 8, wherein the transistor is an organic transistor, and at least the gate insulating film and the organic semiconductor are formed by a wet method.
The method for forming a contact hole according to claim 1, wherein the conductive material includes metal fine particles, and further includes a step of heating the conductive portion of the contact hole to sinter the metal fine particles.
The sintering step is a step of decomposing / removing all or part of the organic matter contained in the conductive portion by UV treatment or a combination of UV treatment and ozone treatment, and sintering metal fine particles by heating. The method for forming a contact hole according to claim 10.
A circuit board including a contact hole for connecting a first conductive member and a second conductive member disposed via an insulating film,
A circuit board, wherein a conductive portion of the contact hole is formed of a liquid repellent photosensitive resin containing a conductive material or a photosensitive resin mixed with a liquid repellent component.
The circuit board according to claim 12, wherein the conductive material includes a conductive nanotube.
The circuit board according to claim 12, wherein the conductive material includes metal fine particles.
The circuit board according to claim 12, wherein the conductive material includes a conductive polymer.
The circuit board is a circuit board on which at least one transistor is formed, and the first conductive member and / or the second conductive member are a lower electrode and / or an upper electrode of the transistor, The circuit substrate according to any one of claims 12 to 15, wherein the insulating film is a gate insulating film of a transistor.