JPS60170176A - Connecting structure with transparent conductive film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a connection structure with a transparent conductive film suitable for use in, for example, a liquid crystal display device.

Background Art and Problems Therein, for example, in a liquid crystal display device, a large number of strizoid transparent electrodes made of a transparent conductive film of an oxide such as tin oxide or a composite oxide of indium and tin are formed in a dense array on a transparent substrate. When connecting and leading out the corresponding external leads to the e-turns, these external leads are formed as a conductive pattern made of a conductive film on another substrate, for example, a flexible substrate, and these conductive holes and turns are connected to transparent electrodes. It is desirable to electrically connect the turns to each other to lead out external leads.

Transparent electric sign Hatan and other conductive No. 4 like this? Connections with turns are generally made using so-called wire endings using, for example, gold wire, or soldering that involves soldering, according to the law.

However, with wire binding using gold wire, the wire itself is expensive, the connection work is complicated and costly because it cannot be connected all at once, and the narrow pitch of the many connections makes it difficult to connect. Problems also arise in reliability, such as contact between wires or narrow bonding portions, resulting in connection strength and short circuits between the bonding portions.

In the case of solder dilag, the narrowing of the joints causes solder to flow between the joints, leading to accidents such as short circuits, and similar reliability problems arise.

Another method is to connect using a so-called zebra connector, but the zebra connector itself does not have a mechanical fixing function and has the disadvantage that it is difficult to maintain a specified width with a constant pressure force. be.

In addition, a connection can be made in which an adhesive layer consisting of a conductive heat-melt type adhesive containing carpin fibers and an insulating heat-melt type adhesive are alternately applied in streaks at the connection between the conductive pattern and the conductor. went. However, in this case, there is a limit to narrowing the width of the streaks, because of narrow pitch electrodes. It has the drawback that it is not suitable for connecting to turns and is extremely complicated to manufacture.

Another method for connecting conductive mother turns to each other is disclosed in Japanese Patent Publication No. 47-2223. In this method, a wiring pattern is formed on a substrate via a thermoplastic adhesive, and two substrates are bonded under heat and pressure to melt the adhesive and join the two substrates together. However, in this case, when the adhesive is melted by heat, the conductive pattern moves and short circuits occur between adjacent turns or between turns. The disadvantage is that it cannot be measured.

Further, it was proposed in Japanese Patent Application No. 41330/1983 that conductive patterns to be connected to each other be connected using an anisotropic connecting sheet. This anisotropic connection sheet is a sheet-like material in which a fibrous conductor such as carbine fiber is oriented and dispersed in an insulating adhesive, and this is attached to a transparent electrode or a pattern on a transparent substrate. With the connecting parts of the conductive wires and turns on the flexible substrate that will be the corresponding external leads to be connected overlapped, the direction of orientation of the fibrous conductor is aligned with the extension direction of these patterns, and the connection is made between the inner substrates. By pressing and heating the adhesive, the two substrates and the conductive turns stacked on each other are mechanically bonded, and the two patterns are pressed together to form a fibrous conductive layer in both patterns. The two patterns are sandwiched so that their bodies are in direct contact with each other to establish an electrical connection between the two patterns.

In this case, since the fibrous conductors are electrically insulated from each other by the adhesive, it is possible to By specifying the length, it is possible to avoid mutual electrical connection between adjacent connection parts, and in addition, both 4' turns are mechanically firmly bonded between the inner boards with adhesive. This ensures a stable electrical connection. When using such an anisotropic connection sheet, it is possible to simultaneously connect conductive wires and turns as external leads to a large number of arranged electrodes and turns without causing short circuits between adjacent electrode patterns. It has the advantage that a connected structure with excellent mass productivity can be obtained.

However, in this case, the connection between both patterns is, for example, a car connection with relatively high electrical resistance. The conduction resistance at each connection part is relatively high because the connection is made by contacting the fiber conductors.Object of the InventionThe present invention solves the above-mentioned drawbacks, and provides a method for forming a large number of oxide transparent conductive films arranged at narrow pitches. A connection structure with a transparent conductive film that enables reliable electrical and mechanical connection of four conductive turns made of a conductive film as an external lead to a transparent electrode pattern made of a transparent electrode pattern. It provides:

Summary of the Invention In the present invention, the connection portions of an oxide transparent conductive film and a conductive film connected thereto are overlapped, and in this overlapped portion, Pb-8n is used as a master alloy, and Zn, An insulating adhesive layer in which metal particles containing at least one kind of rare earth metal are dispersed is interposed, and this adhesive layer is pressed between the oxide transparent conductive film and the conductive film. When heated, the oxide transparent conductive film and the corresponding conductive film are electrically connected by melting the metal particles to form a connection structure with the transparent conductive film.

Here, the metal particles dispersed in the insulating adhesive layer have a relatively low melting point of 50 to 350 °C, preferably 800 to 260 °C.
℃, and the particle size is selected to be sufficiently smaller than this depending on the distance between adjacent transparent conductive films, but from 0.5 μm to
It is desirable that the thickness be selected to be about 2 μm. In addition, for 100 parts by weight of the adhesive (solid content) of this metal particle,
The amount is 5 to 300 parts by weight.

In addition, the thickness of the insulating adhesive layer is 10 to 300% of the volume of the gap that occurs between the inner curtain plates having both the conductive films when the transparent conductive film and the conductive film connected thereto are overlapped.
Preferably, the volume is selected to be 5 to 200%.

In addition, the electrical properties of the insulating adhesive include a specific resistance of 10
It is selected from those with a resistance of 7Ω (7) or more, preferably 100m or more. In addition, its fluidity is 0.001 or more in M, F, I (melt flow index), preferably 0.
．． Selected from 005 or higher. In addition, here M, F,
1 means ASTM, 01238 NoA method or JIS,
K7210 (7) This indicates the number of grams of resin that flows out of the orifice r in 10 minutes when a load of 2160 g is applied at a predetermined compression temperature using a device specified in Method A.

The above-mentioned metal particles in the adhesive layer include pb-8n as a mother alloy, Zn+rare earth metals Sc and Y.

La, Ce, Pr, Nd, Pm, Sm+E
u, Gd+ Tb+ Dy+ Ha.

It is a metal containing at least one of the following: Err Tm + Yb + Lu, and in addition, Sb is added to improve water resistance, At is added to prevent scaling, and At is added to prevent fogging. S l + T l
+Se, and further Bi and Cd can be added to control the melting point.

As described above, in the bonded structure according to the present invention, metal particles, that is, solder particles are placed between the oxide transparent conductive films to be connected to each other and the corresponding conductive films, and the metal particles, that is, the solder material particles are bonded to each other by the heating and pressurization described above. It is used to fusion bond membranes,
Due to this pressure, part or most of the insulating adhesive is pushed outward from between the conductive films stacked on top of each other, and this insulating adhesive effectively binds the metal particles between the adjacent conductive films. Insulation between the transparent conductive film and the conductive film that are wrapped and adjacent to each other is achieved, and the substrates having the conductive film are bonded and held together by an adhesive.

EXAMPLE The present invention will now be described in detail.
As shown in the figure, a transparent conductive oxide film made of a composite oxide of indium oxide and tin oxide is formed on a transparent glass substrate (1) by photo-etching and then turned into stripes and arranged in parallel to form transparent electrodes. A turn is provided, and the other thickness is 25 mm corresponding to the connection part (2) K with the external lead.
μ's, j? A striped conductive pattern (4) was formed on a polyimide flexible substrate (3) made of IJ imide by photo-etching a copper foil with a thickness of 18μ.
) are all connected to each other. In this case, each pitch P between the transparent electrode pattern (2) and the conductive pattern (4) is 0.
．． 4+a+ (width: 02 m, interval: 0.2 tm). In the present invention, these four turns (2) and (4) are arranged so that their connecting parts overlap each other as shown in FIG. 2 in a plan view and in FIG. and an adhesive layer with metal particles dispersed between the two (
5) is used to perform the bonding.

Example I Alloy metal solder particles (melting point: 145° C.) consisting of 30 parts by weight of Tb, 45 parts by weight of Sn, 20 parts by weight of Cd, 3 parts by weight of Zn, and 2 parts by weight of Sb, with a particle size of 20 μm.
110 parts by weight of metal particles of m were uniformly dispersed in a paint having the following composition.

The thickness of the paint mixed with the metal particles mentioned above after drying is 3.
A sheet-like adhesive layer was obtained by coating on a release paper so that the thickness was 0 μm. The inner curtain plates (1) and (3) are sandwiched between the overlapped portions of the transparent electrodes and turns (2) and the conductive patterns (4) explained in FIGS. 1 to 3. At 180°C, which is higher than the melting point of the metal particles sandwiched between them, 40°C
kg/crn", 30 seconds of pressure and heating conditions.The connected structure in which both the arm turns (2) and (4) are electrically and mechanically connected in this way has good electrical properties. A connection has been made.

Example 2 110 parts by weight of metal powder with a particle size of 20 μm of solder for bonding glass ceramics (Cerasolza #143 (melting point, 143° C., manufactured by Asahi Glass Co., Ltd.)) was dispersed and mixed in a paint having the following composition.

The paint in which this metal powder was dispersed was applied onto a release paper so that the thickness after drying was 30 μm to obtain an insulating adhesive layer in which sheet-like metal particles were dispersed. This is peeled off from the release paper, and this insulating adhesive layer is sandwiched between the patterns (2) and (4) which are overlapped with each other as described in FIGS. 1 to 3. 3) When crimping was performed by heating and pressing at 180°C + 40 kg 7 cm for 20 seconds, the conduction resistance between each pattern was less than 100, and the insulation resistance between adjacent patterns was more than 10,100. Even after forced aging at 100°C for one week, the conduction resistance was 100 or less and the insulation resistance was 100 or more.

Example 3 580 parts by weight of metal powder with a particle size of 10 μm of solder for bonding glass ceramics (Cell Solza #123 (manufactured by Asahi Glass Co., Ltd., melting point: 123°C)) was uniformly dispersed and mixed, and spread on release paper so that the thickness after drying was 20 μm. An insulating adhesive layer in which metal particles were dispersed was obtained. This sheet-like insulating adhesive layer was peeled off from the release paper, interposed between the transparent electrode pattern (2) and the conductive pattern (4) explained in FIGS. 1 to 3, and heated at 150°C, 40 kg, and Heat and pressure were applied for seconds. In this embodiment, each pitch P of the transparent electrode/main turn (2) and conductive pattern is 0.3 mm (width 0.3 mm).
This is a case where the interval is 0.15 groups). In this case, no change was observed in electrical conduction resistance and insulation resistance even after one week of forced aging treatment at 80° C. and 95° relative humidity.

Example 4 In this example, a connected structure was obtained by the same method as in Example 2, but the composition of the paint was selected as follows.

The insulating adhesive layer in which the sheet-shaped metal particles obtained in this manner are dispersed is interposed between the mutually overlapping parts of the turns (2) and (4) explained in FIGS. 1 to 3. let 30
0℃, 60kHz, 30kg/6n, 30
Ultrasonic soldering is performed using a device (Asahi Glass Co., Ltd. ZAN?) under conditions of seconds.
Each pattern (2) and (
4) The conduction resistance between the patterns was 50 or less, and the insulation resistance between adjacent patterns was 10,100 or more. As mentioned above, the connection structure according to the present invention has good sag. Connections between the main turns can be made. It is something.

In addition, on each side described above, an insulating adhesive layer in which sheet-shaped metal particles are dispersed is obtained, and this is inserted between the two thread plates to be bonded to each other and crimped. A similar adhesive layer can also be applied directly onto predetermined portions of the substrate (1) or (3) to provide electrical and mechanical bonding thereof.

Effects of the Invention As described above, in the present invention, an insulating adhesive layer in which metal particles, that is, solder metal particles having a special composition are dispersed, is interposed between the oxide transparent electrode pattern and the corresponding conductive e-turn. Electrical connection between the transparent electrode pattern and the corresponding conductive pattern is made by full solder fusion using metal particles by heating and pressurizing the metal particles, and the metal particles existing between adjacent conductive glossy turns are wrapped with an insulating adhesive. This provides insulation between adjacent patterns. Therefore, the conduction resistance between the conductive and main turns is sufficiently small, and the electrical insulation between adjacent conductive patterns can be well achieved. Despite the connection, it is possible to make an electrically and mechanically excellent connection, further promoting the narrowing of the pitch of the nine turns, and making it possible to achieve mass production.

[Brief explanation of the drawing]

FIG. 1 is an exploded plan view for explaining a connection structure with a transparent conductive film according to the present invention, FIG. 2 is an enlarged plan view of the connection structure with a transparent conductive film according to the present invention, and FIG. 3 is an A- A sectional view on line A. (1) is a transparent substrate, (2) is a transparent electrode/cutane made of a conductive film on this, (3) is a flexible substrate, (4)
) It is a conductive turn made of a conductive film which is formed on top of the conductive film and serves as an external lead. Same as Hidehiro Matsukuma 6 (Do, iBi:: 1-2 Figure 3 Figure 3 Continued from page 1 [Phase] Inventor Hidehiro Numao @ Inventor Suzuki Kazuaki Kanuma-shi Satsuki-cho 1 Hata Sony Chemical Corporation Inside Kanuma factory

Claims (1)

[Claims] The oxide transparent conductive film and the conductive film connected thereto are mated together, and Pb-8 is applied to this overlapped part.
An insulating adhesive layer is interposed in which metal particles containing Zn and at least one metal selected from rare earth metals are dispersed, using n as a mother alloy, and the adhesive layer is connected to the oxide transparent conductive film. and the conductive film are heated under pressure,
A connection structure in which the oxide transparent conductive film and the conductive film are electrically connected to each other by melting the metal particles.