WO2010116980A1 - Wiring board and connection structure - Google Patents

Abstract

Disclosed are: a wiring board which is an amorphous film that can be easily patterned by weak acid etching and has low resistance and high transmittance, said amorphous film being able to be easily crystallized and capable of forming a good junction through an anisotropic material; and a connection structure. Specifically disclosed is a wiring board having a wiring pattern that is formed on a transparent substrate, wherein the wiring pattern comprises a connection terminal part that is connected to a member to be connected through an anisotropic conductive material, and at least the surface layer of the connection terminal part is composed of a transparent conductive film that contains indium oxide, and if necessary tin, while containing 0.00001 mole or greater but less than 0.10 mole of barium per 1 mole of indium.

Description

Wiring board and connection structure

The present invention relates to a wiring board and a connection structure that are well connected to a member to be connected via an anisotropic conductive material and have excellent bonding strength.

An indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ composite oxide, hereinafter referred to as “ITO”) film has high visible light transmittance and high electrical conductivity, so that it can be used as a transparent conductive film such as a liquid crystal display device or glass. However, it is difficult to obtain an amorphous film. That is, when patterning is performed by etching after film formation, it is necessary to use a strong acid, and there is a problem that microfabrication is difficult. In particular, in a display substrate such as a liquid crystal display device, a TAB (Tape Automated Bonding) tape equipped with a driver circuit or the like is connected by TCP (Tape Carrier Package), or a COF (Chip On Film) tape is connected by FCB (Flip Chip Bonding). An ITO film is used for a terminal portion to be connected (hereinafter, these connections are referred to as connections to connected members), but miniaturization has progressed year by year and patterning is becoming difficult.

On the other hand, an indium oxide-zinc oxide (IZO) transparent conductive film is known as an amorphous film. However, when such an IZO film is used as a wiring for a liquid crystal display device, connection resistance increases when TCP connection is used. In addition, it has been reported that there is a problem that the connection resistance increases with time (see Patent Document 1).

Further, Patent Document 1 proposes an invention in which the composition range of the IZO film is limited and the surface of the connection portion has crystallinity. However, when TCP connection is performed using an anisotropic conductive material, connection is made. There is a problem that the strength is not sufficient.

On the other hand, the present applicant previously proposed an amorphous transparent conductive film formed by adding silicon to an ITO film under a predetermined condition as a transparent conductive film (see Patent Document 2). There was a problem that there was a tendency to change.

Further, the present applicant can obtain an amorphous film by adding barium to the ITO film as a transparent conductive film, and then anneal to obtain a low resistance and highly transparent film. Moreover, the technique which can improve the corrosion resistance in the post process, moisture resistance, and environmental resistance by this was proposed previously (refer patent document 3).

Japanese Patent No. 3916172 (paragraph [0006], claims, etc.) JP 2005-135649 A (Claims etc.) JP 2007-294447 A (Claims etc.)

In view of such circumstances, the present invention can be easily patterned by weak acid etching with an amorphous film, further has low resistance and high transmittance, can be crystallized more easily, and is bonded via an anisotropic conductive material. It is an object of the present invention to provide a wiring board and a connection structure that can perform the above-described process well.

A first aspect of the present invention that achieves the above object is to provide a wiring board having a wiring pattern formed on a transparent substrate, wherein the wiring pattern is connected to a connected member via an anisotropic conductive material. A transparent conductive film comprising a terminal portion, wherein at least a surface layer of the connection terminal portion contains indium oxide and, if necessary, tin, and barium is contained in an amount of 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium; The wiring board is characterized by the following.

In the first aspect, the surface of the connection terminal portion is made of a transparent conductive film containing indium oxide and tin as required and containing barium in an amount of 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium. Therefore, the connection strength is sufficiently high and stable when connected to the connected member via the anisotropic conductive material.

According to a second aspect of the present invention, in the wiring substrate according to the first aspect, the transparent conductive film is formed as an amorphous film and then crystallized by annealing. Located on the wiring board.

In the second aspect, since the connection terminal portion is annealed and crystallized, the environment resistance is high.

According to a third aspect of the present invention, in the wiring substrate according to the first or second aspect, the transparent conductive film is formed under a condition that the partial pressure of water is less than 1.0 × 10 ⁻⁴ Pa. It is in the wiring board characterized by being.

In the third aspect, since the film is formed in a state where water is not substantially present, the environmental resistance is further improved.

According to a fourth aspect of the present invention, in the wiring substrate according to any one of the first to third aspects, the molar ratio y of tin to 1 mol of indium is expressed by the molar ratio x of barium to 1 mol of indium. (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) or more, and (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ^{− The} wiring board is characterized in that it is in the range excluding y = 0 below the value of ¹ ).

In the fourth aspect, since the surface of the connection terminal portion is made of a transparent conductive film having a predetermined composition range, it is advantageous for patterning, and a high-definition pattern is well patterned.

According to a fifth aspect of the present invention, in the wiring substrate according to any one of the first to third aspects, the molar ratio y of tin to 1 mol of indium is expressed by the molar ratio x of barium to 1 mol of indium. (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) or more, and (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ^{− The} wiring board is characterized by being in the range of ¹ ) or less and excluding y = 0, and in the range of 0.22 or less.

In the fifth aspect, since the surface of the connection terminal portion is made of a transparent conductive film having a predetermined composition range, it is advantageous for patterning, and a high-definition pattern is well patterned.

According to a sixth aspect of the present invention, in the wiring substrate according to the fifth aspect, the molar ratio y of tin to 1 mol of indium is represented by the molar ratio x of barium to 1 mol of indium (5. 9 × 10 ⁻² Ln (x) + 4.9 × 10 ⁻¹ ) or less.

In the sixth aspect, since the surface of the connection terminal portion is made of a transparent conductive film having a predetermined composition range, it is further advantageous for patterning, and a high-definition pattern is well patterned.

According to a seventh aspect of the present invention, in the wiring board according to the sixth aspect, the molar ratio y of tin to 1 mol of indium is 0.08 or more, and the molar ratio x of barium to 1 mol of indium is The wiring board is characterized by being in a range of 0.025 or less.

In the seventh aspect, the resistivity after annealing is very low, the resistivity is as low as 3.0 × 10 ⁻⁴ Ωcm or less, and the resistance after bonding is also low.

According to an eighth aspect of the present invention, there is provided the wiring board according to any one of the first to seventh aspects, and a connected member that is thermocompression bonded to the connection terminal portion of the wiring board via an anisotropic conductive material. It is in the connection structure characterized by comprising.

In the eighth aspect, the connection terminal portion and the member to be connected via the anisotropic conductive material have good connection strength and high durability.

According to a ninth aspect of the present invention, in the connection structure according to the eighth aspect, the wiring board is a substrate for display display, and the pixel group provided on the transparent substrate and the pixel group are drawn out from the pixel group. And a wiring group, wherein the connection terminal portion is connected to the wiring group.

In the ninth aspect, a display device with high connection strength and high durability can be realized.

It is the schematic plan view and sectional drawing of the connection structure which concern on one Embodiment of this invention. It is a figure which shows the connection structure of the ACF connection test of the test example of this invention. It is a figure which shows the time-dependent change of ACF connection resistance of Example 1 of this invention. It is a figure which shows the time-dependent change of ACF connection resistance of the comparative example 1 of this invention. It is a figure which shows the time-dependent change of ACF connection resistance of the comparative example 2 of this invention. It is a figure which shows the state after the ACF connection test of Example 1 of this invention. It is a figure which shows the state after the ACF connection test of the comparative example 1 of this invention. It is a figure which shows the state after the ACF connection test of the comparative example 2 of this invention.

The wiring board of the present invention is not particularly limited as long as it includes a connection terminal portion connected to a connected member via an anisotropic conductive material. Moreover, as long as at least the surface layer of the connection terminal portion is made of a transparent conductive film having a predetermined composition, the material of the wiring other than the connection terminal portion is not particularly limited, and the entire connection terminal portion has a predetermined composition in the thickness direction. The indium oxide-based transparent conductive film may be formed, or a transparent conductive film having a predetermined composition may be formed on a terminal portion made of a different material. In addition, since the conductive film of a predetermined composition is transparent, it is a transparent conductive film. However, it goes without saying that the characteristic of being transparent may not be used, for example, the substrate is not a transparent substrate. Is included.

The use of such a wiring board is not particularly limited as long as it is intended for connection with an anisotropic conductive material, but a wiring board for display display is particularly preferable.

Here, the display display wiring board is a liquid crystal display wiring board, a plasma display wiring board, an organic or inorganic EL wiring board, and the like, and generally includes a transparent substrate provided with a pixel group. And a wiring group led out from the pixel group. In such a display display wiring board, it is sufficient that at least the surface layer of the connection terminal portion connected to the wiring group is made of an indium oxide-based transparent conductive film having a predetermined composition, and the material of the wiring group connected thereto is not particularly limited, It may be a film made of the same material, a film made of another transparent conductive material, or a film made of a conductive metal, and is not particularly limited.

Moreover, the connection structure of the present invention includes the above-described wiring board and a connected member that is thermocompression bonded to the connection terminal portion of the wiring board via an anisotropic conductive material, and the use thereof is as follows. Although not particularly limited, it is particularly preferable that the wiring board is a display display wiring board.

Here, an example of a connection structure provided with a display display wiring board will be described with reference to FIG. 1A is a schematic plan view of the connection structure, and FIG. 1B is a schematic cross-sectional view. As shown in these drawings, the display display wiring substrate 10 includes a pixel group 12 formed on a transparent substrate 11. Thus, the end portion of the wiring group 13 drawn out from the pixel group 12 becomes the connection terminal portion 14. A carrier tape 30 of a TAB tape or a COF tape, which is an example of a member to be connected, is thermocompression bonded to the connection terminal portion 14 in which a plurality of terminals are arranged in parallel via an anisotropic conductive material 20.

Here, the anisotropic conductive material 20 is an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP), and a known material can be used. Further, the connected member is not limited to a carrier tape such as a TAB tape or a COF tape.

Hereinafter, the indium oxide-based transparent conductive film having a predetermined composition constituting at least the surface layer of the connection terminal portion described above will be described. Such a transparent conductive film having a predetermined composition contains indium oxide and tin as required and contains barium in an amount of 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium. It has been done.

When such an indium oxide-based transparent conductive film is formed by sputtering, the transparent conductive film sputtering target used is mainly composed of indium oxide and contains tin as required, and oxide sintering containing barium. The barium is not particularly limited as long as it is in the form of its oxide, as a composite oxide, or as a solid solution.

The barium content is preferably in a range formed by using a sputtering target containing 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium. If it is less than this, the effect of addition is not remarkable, and if it is more than this, the resistance of the formed transparent conductive film tends to increase and the color tends to deteriorate. In addition, barium content in the transparent conductive film formed with the sputtering target mentioned above turns into content same as content in the used sputtering target.

Further, the content of tin is within a range in which a film is formed using a sputtering target containing 0 to 0.3 mol per 1 mol of indium. When tin is contained, it is desirable to form a film using a sputtering target contained in a range of 0.001 to 0.3 mol with respect to 1 mol of indium. Within this range, the density and mobility of carrier electrons in the sputtering target can be appropriately controlled to keep the conductivity in a good range. Further, addition beyond this range is not preferable because the mobility of carrier electrons of the sputtering target is lowered and the conductivity is deteriorated. In addition, content of the tin in the transparent conductive film formed with the sputtering target mentioned above turns into content same as content in the used sputtering target.

Since such a sputtering target has a resistance value that can be sputtered by DC magnetron sputtering, it can be sputtered by a relatively inexpensive DC magnetron sputtering. Of course, a high-frequency magnetron sputtering apparatus may be used. .

By using such a transparent conductive film sputtering target, an indium oxide-based transparent conductive film having the same composition can be formed. For the composition analysis of such an indium oxide-based transparent conductive film, the entire amount of a single film may be dissolved and analyzed by ICP. In addition, when the film itself has an element configuration, if necessary, a cross section of the corresponding part is cut out by FIB or the like, and an element analyzer (EDS, WDS, Auger analysis, etc.) attached to the SEM, TEM, etc. ) Can also be specified.

The indium oxide-based transparent conductive film formed in this manner contains a predetermined amount of barium, and thus varies depending on the barium content. The film is formed in an amorphous state by performing under a temperature condition lower than 150 ° C., preferably lower than 150 ° C., and more preferably lower than 100 ° C. Further, such an amorphous film has an advantage that it can be etched with a weakly acidic etchant. Here, in the present specification, the etching is included in the patterning step and is for obtaining a predetermined pattern. And the connection terminal part which has the obtained indium oxide type transparent conductive film in a surface layer has a favorable connection with a to-be-connected member via an anisotropic conductive material, sufficient connection strength is obtained, and durability It has the advantage of being excellent.

Further, the resistivity of the transparent conductive film obtained varies depending on the barium content, but the resistivity is 1.0 × 10 ⁻⁴ to 1.0 × 10 ⁻³ Ωcm.

Furthermore, the crystallization temperature of the deposited film varies depending on the content of barium contained, and increases as the content increases, but it can be crystallized by annealing at a temperature of 100 ° C. to 400 ° C. it can. Since such a temperature region is used in a normal semiconductor manufacturing process, it can be crystallized in such a process. In this temperature range, those that crystallize at 100 ° C. to 300 ° C. are preferred, crystals that crystallize at 150 ° C. to 250 ° C. are more preferred, and those that crystallize at 200 ° C. to 250 ° C. are most preferred.

Here, annealing refers to heating at a desired temperature for a certain period of time in air, atmosphere, or vacuum. The fixed time is generally several minutes to several hours, but a short time is preferred industrially if the effect is the same.

Thus, the transparent conductive film after crystallization by annealing has improved transmittance on the short wavelength side, for example, the average transmittance at a wavelength of 400 to 500 nm is 85% or more. This also eliminates the problem of a yellowish film that is a problem with IZO. In general, a higher transmittance on the short wavelength side is preferred.

On the other hand, the crystallized transparent conductive film has improved etching resistance and cannot be etched with a weakly acidic etchant that can be etched with an amorphous film. This improves the corrosion resistance in the subsequent process and the environmental resistance of the device itself.

And in this invention, it is preferable that the transparent conductive film which comprises the surface layer of a connection terminal part is annealed before connecting through an anisotropic conductive material, and it is in this transparent crystallized conductive film By connecting to the member to be connected through the anisotropic conductive material, the connection strength is sufficiently high and the durability is excellent.

Thus, in the indium oxide transparent conductive film having a predetermined composition used in the present invention, the crystallization temperature after film formation can be set to a desired temperature by changing the barium content. The amorphous state may be maintained without being subjected to heat treatment at a temperature higher than the temperature, or after patterning after film formation, heat treatment is performed at a temperature equal to or higher than the temperature for crystallization, and crystallization is achieved. It may be changed.

Furthermore, when forming an indium oxide-based transparent conductive film containing barium, the optimum oxygen partial pressure changes depending on the temperature depending on the composition range of the sputtering target, and an amorphous film is formed at a temperature oxygen partial pressure that becomes low resistance after annealing. A low resistance transparent conductive film is formed by forming a film and then annealing and crystallizing the film.

That is, the molar ratio y of tin to 1 mol of indium is represented by the molar ratio x of barium to 1 mol of indium (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) Or more and less than (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ⁻¹ ) and in a range excluding y = 0, the resistance of the deposited amorphous film The optimal oxygen partial pressure that is the lowest oxygen partial pressure, and the oxygen partial pressure that provides the lowest resistance of the crystallized film after annealing (or the optimal oxygen partial pressure when deposited at the annealing temperature) Is different. Therefore, in this range, it is possible to obtain a transparent conductive film having a low resistance if the film is formed at an oxygen partial pressure that has a low resistance after annealing, or a film can be formed at a low oxygen concentration even if the resistance is the same. You can get a profit.

Further, the etching rate varies depending on the composition, and the molar ratio y of tin to 1 mol of indium is represented by the molar ratio x of barium to 1 mol of indium (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) or more, (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ⁻¹ ) or less and excluding y = 0, When the etching rate is in the range of 0.22 or less, the etching rate is particularly high. For example, as will be described in detail later, etching using an etchant in which a solution having an oxalic acid concentration of 50 g / L is heated to 30 ° C. is used. The rate is 3 kg / sec or more. Further, among these, the range in which the molar ratio y of tin is not more than the value of (5.9 × 10 ⁻² Ln (x) + 4.9 × 10 ⁻¹ ) represented by the molar ratio x of barium to 1 mol of indium. However, the etching rate is further increased, and the etching rate when an etchant obtained by heating a solution having an oxalic acid concentration of 50 g / L to 30 ° C. is 4 Å / sec or more. In such an etching rate region, a good pattern can be obtained during patterning. The upper limit of the etching rate is generally said to be about 30 liters / sec.

Further, in such a composition range where the etching rate is high, there is a range where the resistance is particularly low. That is, in the range where the etching rate is high, the molar ratio y of tin to 1 mol of indium is 0.08 or more, and in the range where the molar ratio x of barium to 1 mol of indium is 0.025 or less, the resistivity is A transparent conductive film of 3.0 × 10 ⁻⁴ Ωcm or less is preferable.

Therefore, by using a sputtering target having such a composition range and forming a transparent conductive film having such a composition range, the film is crystallized after the film formation. A transparent conductive film having excellent etching resistance and low resistance is obtained.

Next, the manufacturing method of the sputtering target used in the present invention will be described. However, this is merely an example, and the manufacturing method is not particularly limited.

First, the starting material constituting the sputtering target of the present invention is generally a powder of In ₂ O ₃ , SnO ₂ , or BaCO ₃ , but In ₂ O ₃ and BaCO ₃ are pre-calcined to BaIn _2. It is preferable to use O ₄ in a mixture of In ₂ O ₃ and SnO ₂ . This is to prevent generation of pores due to gas generation due to decomposition of BaCO ₃ . These simple substances, compounds, composite oxides, and the like may be used as raw materials. When using a simple substance or a compound, it is made to go through a process of making it oxide in advance.

The method of mixing and molding these raw material powders at a desired blending ratio is not particularly limited, and various conventionally known wet methods or dry methods can be used.

Examples of the dry method include a cold press method and a hot press method. In the cold press method, the mixed powder is filled in a mold to produce a molded body and fired. In the hot press method, the mixed powder is fired and sintered in a mold.

As the wet method, for example, a filtration molding method (see JP-A-11-286002) is preferably used. This filtration molding method is a filtration molding die made of a water-insoluble material for obtaining a molded body by draining water from a ceramic raw material slurry under reduced pressure, and a lower molding die having one or more drain holes And a water-permeable filter placed on the molding lower mold, and a molding mold clamped from the upper surface side through a sealing material for sealing the filter, the molding lower mold, Forming mold, sealing material, and filter are assembled so that they can be disassembled respectively. Using a filtration mold that drains water in the slurry under reduced pressure only from the filter surface side, mixed powder, ion-exchanged water and organic Prepare a slurry consisting of additives, inject the slurry into a filtration mold, drain the water in the slurry only from the filter surface side, and produce a molded body. After drying degreasing, and firing.

The firing temperature of the one formed by the cold press method or the wet method is preferably 1300 to 1650 ° C., more preferably 1500 to 1650 ° C., and the atmosphere is an air atmosphere, an oxygen atmosphere, a non-oxidizing atmosphere, a vacuum atmosphere, or the like. It is. On the other hand, in the case of the hot press method, sintering is preferably performed at around 1200 ° C., and the atmosphere is a non-oxidizing atmosphere, a vacuum atmosphere, or the like. In addition, after baking in each method, the machining for shaping | molding and a process is given to a predetermined dimension, and it is set as a target.

Example 1
A sputtering target of Ba-added ITO (In: Sn: Ba = 86.2 at%: 12.9 at%: 0.86 at%) was mounted on a 4-inch DC magnetron sputtering apparatus, and the thickness was 6000 mm under the following conditions. A membrane was obtained.

Target dimension: φ = 4 in. t = 6mm
Sputtering method: DC magnetron sputtering Exhaust device: Rotary pump + cryopump Ultimate vacuum: 5.0 × 10 ⁻⁵ [Pa]
Ar pressure: 4.0 × 10 ⁻¹ [Pa]
Oxygen pressure: 2.1 × 10 ⁻³ [Pa]
Water pressure: 5.0 × 10 ⁻⁵ [Pa]
Substrate temperature: Room temperature Sputtering power: 130 W (Power density 1.6 W / cm ² )
Substrate used: Corning # 1737 (glass for liquid crystal display)
t = 0.8mm

(Comparative Example 1)
Sputtering targets of IZO (In: Zn: Sn = 83.1 at%: 16.9 at%: 0.86 at%) were respectively mounted on a 4-inch DC magnetron sputtering apparatus, and an oxygen pressure of 5.2 × 10 ⁻³ [Pa ] A film having a thickness of 6000 mm was obtained under the same conditions as in Example 1 except that.

(Comparative Example 2)
A 4 inch DC magnetron sputtering system with an ITO (In: Sn = 90.8 at%: 9.2 at%) sputtering target, an oxygen pressure of 0 (ITO) [Pa], and an amorphous film capable of weak acid etching Thus, a film having a thickness of 6000 mm was obtained under the same conditions as in Example 1 except that water vapor gas was added during film formation (moisture pressure 1.0 × 10 ⁻² [Pa]).

(Test example)
FIG. 2 shows a plan view and a side view of a test pattern for performing a connection test for ACF connection. As shown in FIG. 2, three strip-shaped patterns 102 formed on a glass substrate 101 with a size of 20 mm × 3 mm at intervals of 5 mm are obtained by applying each film sample formed in the above-described example and comparative example to an oxalic acid type. Etching (ITO-07N, manufactured by Kanto Chemical Co., Inc.) was used, and the Ba-added ITO and ITO films were annealed at 250 ° C. for 1 hour in the atmosphere to crystallize the films.

Next, the strip pattern 102 of each film sample and the gold-deposited copper foil 103 (thickness 50 μm) were combined into an anisotropic conductive adhesive 104 (AC-4251FY, Hitachi, 1 mm thick × 30 mm long) as shown in FIG. Using Kasei). Further, a lead wire 105 is bonded to the opposite end of the connection surface between the strip pattern and the ACF as a resistance measurement terminal by solder 106, and test sample 1 (Example 1: Ba-added ITO film) and test sample 2 ( Comparative Example 1: IZO film) and test sample 3 (Comparative Example 2: ITO film) were prepared.

Each test sample prepared was measured for 250 hours in the ACF connection resistance (3 locations) when a bias of ± 5 V and 60 Hz was applied in a thermo-hygrostat set at a temperature of 60 ° C. and a humidity of 90%. The change with time was examined.

Figures 3 to 5 show the changes over time in the ACF connection resistance of each test sample. In the Ba-added ITO film of Example 1 and the ITO film of Comparative Example 2, the initial resistance and the resistance after 250 hours hardly changed at all three locations, and no change with time was observed. On the other hand, in the IZO film of Comparative Example 2, the resistance increased 20 to 30 hours after the start of the test. In particular, no. In No. 2, after about 70 hours, a large resistance fluctuation considered to be caused by peeling of the joint was confirmed. This is because the Ba-added ITO film or ITO film is crystallized by annealing, but the IZO film is kept in an amorphous state. In general, it is known that the amorphous state has more lattice defects, is structurally sparse, and has a lower density than the crystallized state. For this reason, in an IZO film that is in an amorphous state, moisture in the atmosphere is adsorbed during the test, and the moisture also enters the bonding interface, thereby causing a decrease in adhesion at the joint and peeling. It is thought that. The IZO film used in this test is generally formed near room temperature and used in an amorphous state. In addition, since the crystallization temperature of the IZO film is 500 ° C. or higher, it is not crystallized by annealing (about 200 to 250 ° C.) in the liquid crystal panel manufacturing process.

6 to 8 show an overview of the ACF connection part after 250 hours of ACF connection resistance measurement. In the Ba-added ITO of Example 1 and the ITO of Comparative Example 2, the ACF and the transparent conductive film were firmly connected, and no change was observed on the overview compared to before the test. On the other hand, in the IZO of Comparative Example 1, peeling was confirmed at the joint between the ACF and the transparent conductive film in the portion surrounded by a circle. Furthermore, it was confirmed that ACF was altered and dissolved. As described above, the film is taken into the film while adsorbing moisture in the atmosphere at the time of the test, moisture enters the junction between the film and the ACF, and further, the water is immersed in the ACF, so that the ACF is altered. It is thought that it melted and caused a decrease in adhesion at the joint between the ACF and the transparent conductive film.

(Other examples)
Transparent conductivity having a composition of (In: Sn: Ba = 89.3 at%: 8.9 at%: 1.78 at%), (In: Sn: Ba = 86.6 at%: 13.0 at%: 0.43 at%) When the ACF connection test was conducted using the film in the same manner as in Example 1, it was confirmed that there was no change with time in the ACF connection resistance as in Example 1, the connection state was maintained and there was no decrease in adhesion. .

DESCRIPTION OF SYMBOLS 10 Display display wiring board 11 Transparent substrate 12 Pixel group 13 Wiring group 14 Connection terminal part 20 Anisotropic conductive material 30 Carrier tape (member to be connected)
101 Glass substrate 102 Strip pattern (transparent conductive film)
103 Gold-deposited copper foil 104 Anisotropic conductive adhesive 105 Lead wire 106 Solder

Claims (9)

1. In a wiring board having a wiring pattern formed on a transparent substrate, the wiring pattern includes a connection terminal part connected to a connected member via an anisotropic conductive material, and at least a surface layer of the connection terminal part is A wiring substrate comprising a transparent conductive film containing indium oxide and tin as required and containing barium in an amount of 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium.
2. 2. The wiring board according to claim 1, wherein the transparent conductive film is formed as an amorphous film and then crystallized by annealing.
3. 3. The wiring board according to claim 1, wherein the transparent conductive film is formed under a condition that a partial pressure of water is less than 1.0 × 10 ⁻⁴ Pa. ⁴ .
4. 4. The wiring board according to claim 1, wherein a molar ratio y of tin to 1 mol of indium is represented by a molar ratio x of barium to 1 mol of indium (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) or more, and (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ⁻¹ ) or less and y = A wiring board having a range excluding 0.
5. 4. The wiring board according to claim 1, wherein a molar ratio y of tin to 1 mol of indium is represented by a molar ratio x of barium to 1 mol of indium (−2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) or more, and (−2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ⁻¹ ) or less and y = A wiring board having a range excluding 0 and a range of 0.22 or less.
6. 6. The wiring board according to claim 5, wherein a molar ratio y of tin to 1 mol of indium is represented by a molar ratio x of barium to 1 mol of indium (5.9 × 10 ⁻² Ln (x) +4). .. A wiring board having a value of 9 × 10 ⁻¹ ) or less.
7. The wiring board according to claim 6, wherein the molar ratio y of tin to 1 mol of indium is 0.08 or more, and the molar ratio x of barium to 1 mol of indium is in the range of 0.025 or less. A characteristic wiring board.
8. 8. A connection comprising: the wiring board according to claim 1; and a connected member thermocompression bonded to the connection terminal portion of the wiring board via an anisotropic conductive material. Construction.
9. 9. The connection structure according to claim 8, wherein the wiring board is a display display substrate, and includes a pixel group provided on a transparent substrate and a wiring group drawn from the pixel group, and the connection terminal. A connection structure characterized in that a portion is connected to the wiring group.

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