JPH07321158A - Film carrier, liquid crystal display device equipped with it and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a film carrier whose wiring terminals are very reliably connected to other electrode terminals and which can be improved in productivity. CONSTITUTION:Wiring patterns 12 are formed on an organic insulating film 11 for the formation of a film carrier 10, the ends of the wiring patterns 12 are arranged in lines as wiring terminals 12a, and a wiring terminal group is electrically connected to other wiring terminal groups, and through-holes 15 are bored in the organic film 11 between the wiring terminals 12a on both the sides of a belt section that extends along the alignments of the wiring terminal 12, excluding the above belt section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier in which a wiring pattern is provided on an organic insulating film, a liquid crystal display device using the same and a method for producing the same. More specifically, the film carrier that improves reliability of electrical connection between the wiring terminal group provided at the end of the film carrier and another electrode terminal group and does not damage the pressurizing and heating tool at the time of connection. And a liquid crystal display device using the same and a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, in a flat-panel display element such as a liquid crystal display element, electrode terminals connected to electrodes provided for each pixel and a drive circuit for driving each pixel electrode are connected to each other so that they can be bent. A film carrier having a wiring pattern formed of a copper foil or the like on a flexible film is used.

Here, the film carrier is preferably a flexible organic insulating film provided with a wiring pattern by a lead wire or a copper foil, and a signal processing IC or a drive is provided in the middle of the wiring pattern. LS with circuit
A so-called TAB on which I or the like is mounted, a flexible connector for connecting the electrode terminal group of the flat display panel and the terminal of the circuit board on which the drive circuit is formed, which is provided only with the wiring pattern, etc. Is also meant to include.

In recent years, liquid crystal display elements have been tending toward larger screens and higher definition of display panels, and the number of electrode terminals has been increasing, resulting in miniaturization. Along with that, the method of connecting the liquid crystal cell electrode terminal group and the liquid crystal cell driving LSI is to connect the LSI to the conventional printed circuit board by the wire bonding method and then heat seal, zebra rubber, etc. There has been a change from a method of connecting to a liquid crystal cell driving LSI on a film carrier and a method of connecting to an electrode terminal group of a liquid crystal cell by using an anisotropic conductive film.

An example of a film carrier provided with a conventional LSI is shown in FIG.
FIG. 7 shows the procedure for connecting the electrode terminal 22 portion of No. 0.

In FIG. 6, 11 is a flexible organic insulating film, on the surface of which a wiring pattern 12 is provided,
The wiring terminal 12a is provided at one end and the LSI 30 is provided at the other end.
Are connected, and a wiring pattern 12 is further provided. Reference numeral 13 is an alignment mark, and 16 is an opening for facilitating bending of the film carrier. The wiring terminals 12a of the film carrier 10 are electrically connected to the electrode terminals of the liquid crystal cell, for example, as follows.

First, as shown in FIG. 7 (a), an anisotropic conductive film 40 is placed on the electrode terminals 22 of the liquid crystal cell 20, the film carrier 10 is further stacked, and the wiring terminals 12a are connected to the liquid crystal cell. The film carrier 10 is aligned with the liquid crystal cell 20 so as to coincide with the group of the electrode terminals 22 at the end of the substrate 21 of 20. At this time, voids 41 are formed between the wiring terminals 12a of the film carrier 10 and between the electrode terminals 22 of the liquid crystal cell 20. Next, as shown in FIG. 7B, the heating / pressurizing tool 50 is attached to the film carrier 1.
0 from the side of the organic insulating film 11 on the wiring terminal 12a portion, 150 to 220 ℃, 2 × 10 ^{5 to} 5 × 10 ⁵
The anisotropic conductive film 40 is cured by heating and pressurizing to Pa. The anisotropic conductive film 40 is a mixture of conductive particles in a thermosetting resin, and when heated, the thermosetting resin becomes liquid, and when pressed, it is extruded toward the void portion 41 side. The two terminals are electrically connected via the conductive particles sandwiched between the wiring terminal 12a and the electrode terminal 22. On the other hand, since the thermosetting resin extruded into the void 41 is not a narrow gap such as between the wiring terminal 12a and the electrode terminal 22, the conductive particles are scattered in the thermosetting resin, and both sides (lateral) There is no short circuit between terminals (direction), and only the required wiring terminal 12a and electrode terminal 2 can be electrically connected. However, the thermosetting resin extruded into the void 41 has its viscosity drastically lowered in a heated state and has extremely good fluidity, so that the air originally present in the void 41 is pushed out. It is not possible, and it will be taken into the resin. As a result, FIG. 7 (b), (c)
As shown in (4), bubbles 42 are generated, insulation failure between adjacent terminals occurs, adhesion strength between the film carrier 10 and the end of the liquid crystal cell 20 decreases, and peeling occurs,
There is a problem that moisture penetrates to lower reliability.
It should be noted that FIG. 7C is a diagram showing a state in which the heating / pressurizing tool 50 is removed after the thermosetting resin is cured.

On the other hand, in order to solve such a problem, for example, it is disclosed in Japanese Patent Laid-Open No. 4-256926, and FIG.
The film carrier 10 as shown in FIG. The film carrier 10 is provided with through holes 15 on the organic insulating film 11 and between the wiring terminals 12a in the entire wiring terminal 12a portion of the wiring pattern 12.
The air existing between the wiring terminals 12a and between the electrode terminals 22 is allowed to escape from the through holes 15 to the outside. FIG. 9 shows the procedure for connecting the film carrier 10 and the liquid crystal cell 20 shown in FIG. As in the case of the film carrier 10 shown in FIG. 6 described above, as shown in FIG. 9A, the anisotropic conductive film 40 is provided on the electrode terminal 22 provided at the end of the substrate 21 of the liquid crystal cell 20. Then, the film carrier 10 is further overlapped, and the wiring terminals 12a are aligned so that the wiring terminals 12a and the electrode terminals 22 of the liquid crystal cell 20 are aligned with each other. As shown in FIG. Bonding is performed with the anisotropic conductive film 40. At this time, the air existing in the voids 41 escapes through the through holes 15 of the film carrier 10, but a part of the anisotropic conductive material 43 also crawls into the through holes 15 and is heated by the heat treatment shown in FIG. The deposit 44 is formed on the heating and pressing tool 50 as shown after the pressing tool is removed.

[0009]

As described above, when the film carrier is not provided with the through holes, air bubbles are trapped in the anisotropic conductive material, and the insulating property and the adhesive strength are lowered. There is. When the film carrier must be peeled off after the liquid crystal cell and the film carrier are connected due to a malfunction of the liquid crystal driving LSI, a solvent such as acetone, toluene, or methyl ethyl ketone is used. Since the solvent can be sent only from around the carrier,
There is a problem that the anisotropic conductive material does not swell sufficiently and peeling is extremely difficult, and the electrode terminals of the liquid crystal cell are peeled together when peeling.

Further, when the film carrier is provided with a through hole, a part of the material forming the anisotropic conductive film flows out from the through hole to form an adhered substance on the heating / pressurizing tool, which is heated. The pressure tool becomes uneven. There is a problem in that the heating / pressurizing tool must be cleaned after each operation, because uniform pressing cannot be performed unless it is flat.

An object of the present invention is to provide a film carrier which solves such a problem, has highly reliable connection of electrode terminals, and has improved productivity.

Another object of the present invention is to provide a liquid crystal display device using the film carrier, which has improved reliability and is inexpensive, and a method for producing the same.

[0013]

In the film carrier of the present invention, a plurality of wiring patterns are formed on an organic insulating film, the ends of the plurality of wiring patterns are aligned as wiring terminals, and a group of the wiring terminals is formed. Is a film carrier that can be electrically connected to another electrode terminal group, and the organic film is formed on both sides of the strip-shaped portion except the strip-shaped portion along the alignment direction of the wiring terminals and in the gap between the wiring terminals. Through holes are provided in the insulating film.

One of the through holes in the vicinity of both ends of the wiring terminal in the alignment direction is formed to have a different shape or size from the other through holes, which is used as an alignment mark of the film carrier. It is preferable because it is possible.

Further, it is preferable that the alignment mark of the film carrier is formed on the film carrier so as to project to the inner side of one of the through holes from the viewpoint of improving the alignment accuracy.

Further, the liquid crystal display device of the present invention comprises a liquid crystal cell in which a liquid crystal material is sandwiched between two insulating transparent substrates having electrode patterns, and electrode terminal groups of the electrode patterns are provided at the ends. A drive circuit for driving the liquid crystal cell, wherein the electrode terminal group of the liquid crystal cell and the terminal of the drive circuit are connected by the film carrier according to claim 1.

Here, the drive circuit is a circuit in which at least a part of the drive circuit for sending a signal to each pixel of the liquid crystal display element is formed, and the circuit formed on the circuit board is IC, L.
In addition to the one formed in SI, it is meant to include a signal processing IC capable of performing some signal processing and reducing the number of wirings.

Further, according to the method of manufacturing a liquid crystal display element of the present invention, an electrode terminal group of a liquid crystal cell in which a liquid crystal material is sandwiched by two insulating transparent substrates having electrode patterns formed thereon, and a drive circuit is connected to the other end. A liquid crystal display manufacturing method for electrically connecting a plurality of wiring patterns having a group of wiring terminals at one end to the wiring terminal group of a film carrier formed on an organic insulating film, wherein the organic insulating A film carrier in which a through hole is provided between the wiring terminals on both sides of the strip-shaped portion except for the strip-shaped portion in the direction in which the wiring terminals are aligned with the film, each terminal of the wiring terminal group is an electrode terminal group of the liquid crystal cell. The terminals are overlapped with each other via an anisotropic conductive film so as to match each terminal, and a heating and pressurizing tool is applied to the band-shaped portion where the through hole is not provided to bond the terminals together with the electrode terminal group. Characterized by electrically connecting the wiring terminals.

[0019]

According to the present invention, since the through hole is provided in the organic insulating film between the wiring terminals in the area excluding the strip-shaped portion in contact with the heating and pressing tool in the wiring terminal portion of the film carrier. The air existing in the voids between the terminals when connecting the liquid crystal display element, the wiring terminal group of the film carrier, and the other electrode terminal groups penetrates when the anisotropic conductive material is pushed into the voids by heat and pressure. It is released through the pores and is not left as bubbles in the anisotropic conductive material. Therefore, the insulation between the terminals can be surely obtained, and the adhesive force can be sufficiently obtained, so that the reliability is improved.

On the other hand, since no through hole is provided in the area where the film carrier and the heating and pressing tool are in contact with each other,
Even if the material of the anisotropic conductive film is extruded into the void by heating and pressing, it does not adhere to the heating and pressing tool.

Further, by providing through holes having different sizes or shapes one by one in the vicinity of both ends in the alignment direction as positioning marks, or by providing positioning marks protruding into the through holes, The wiring terminal group is not formed even when the wiring terminal group of the new film carrier is aligned with other electrode terminal groups provided in the liquid crystal cell etc. after the film carrier is peeled off due to an LSI defect or the like. From the side, the mark for aligning the film carrier and the mark on the liquid crystal cell can be seen at the same time, and the alignment can be ensured.

According to the liquid crystal display element and the manufacturing method thereof of the present invention, a group of electrode terminals provided at the end of the liquid crystal cell,
The connection with the wiring terminal of the film carrier having the wiring pattern connected to the driving LSI or the driving circuit can be surely obtained, and a highly reliable liquid crystal display element can be obtained. Moreover, the anisotropic conductive material does not adhere to the heating / pressurizing tool that heats and presses by placing the heating / pressurizing tool on the wiring terminal portion where the through hole is not formed.

[0023]

The film carrier of the present invention will now be described with reference to the drawings.

[Embodiment 1] FIG. 1 (a) is an illustration of an embodiment of the film carrier of the present invention, and FIG. 1 (b) is FIG.
FIG. 2A is a sectional view taken along the line AA of FIG. 2A, and FIGS. 2 to 3 are sectional explanatory views showing a process of connecting a liquid crystal cell and a film carrier for forming a liquid crystal display element.

The film carrier 10 is formed of an organic insulating film 11 made of a polyimide resin or a polyester resin and a conductive metal foil such as a copper foil or a copper-based alloy foil by photolithography. Wiring pattern 12 whose part is a wiring terminal 12a
And the alignment mark 13 formed of the same material as the wiring pattern 12 at the same time. Further, as shown in FIG. 1A, a plurality of through holes 15 are formed between the wiring terminals 12a of the organic insulating film 11 except for the strip-shaped portion P pressed by the heating and pressing tool. As a method of forming the through hole 15, a conventionally used method such as mechanical punching using a press, chemical etching using a special solvent such as hydrazine, or laser cutting can be employed. This through hole 1
5 may be formed before or after the liquid crystal cell driving LSI 30 is mounted on the film carrier 10. Further, as described above, the through hole 15 is formed at a position where a heating and pressing tool to be used later does not come into contact with the through hole 15. The size of the through hole 15 is preferably about 5 to 500 μm, although it depends on the pitch of the electrode terminals.

The procedure for connecting the electrode terminals provided at the end portions of the substrate of the liquid crystal cell and the wiring terminals 12a of the film carrier 10 using the film carrier 10 of FIG.
FIG. 2 showing a part of the cross section taken along the line AA of FIG.
It demonstrates using FIG. 3 which showed a part of BB sectional drawing of (a).

As shown in FIG. 2A, the anisotropic conductive film 40 is stacked so that the electrode terminals 22 provided at the ends of the substrate 21 of the liquid crystal cell 20 are in contact with each other, and the wiring of the film carrier 10 is further provided. The film carrier 10 and the liquid crystal cell 20 are aligned so that the pattern 12 matches the electrode terminal 22 of the liquid crystal cell 20. At this time, voids 41 are formed between the wiring terminals 12a of the film carrier 10 and between the electrode terminals 22 of the liquid crystal cell 10.

Here, the liquid crystal cell 20 is manufactured by a usual method. For example, two insulating transparent substrates provided with a pattern of an electrode film, an alignment film and the like are adhered at a constant gap, and in the gap. A liquid crystal material is encapsulated. Usually, a polarizing plate is further arranged outside the both transparent substrates.

Next, the heating / pressurizing tool 50 made of a low carbon steel such as SUS304 is used to remove the organic insulating film 11 in the strip portion P of the film carrier 10 where the above-mentioned through holes 15 are not provided. Press from above,
By heating and pressurizing, the anisotropic conductive film 40 is cured by heating. At this time, the anisotropic conductive material 4 is placed in the space 41 between the terminals.
3 is extruded, but since the through hole 15 is provided in the organic insulating film 11 adjacent to the heating / pressurizing tool 50, the air in the void 41 is discharged to the outside through the through hole 15. Therefore, no bubbles are formed in the anisotropic conductive material 43. In addition, the through hole 15 is a heating and pressing tool 50.
Organic insulating film 11 in area P (see FIG. 1)
2C, the anisotropic conductive material that has flowed out to the heating / pressurizing tool 50 does not adhere to the heating / pressurizing tool 50, as shown in FIG. Further, in the portion without the heating / pressurizing tool 50, as shown in FIG. 3, the terminals 12a and 22 are connected to each other by being pressed to some extent by the elastic force of the organic insulating film 11, and the air in the void 41 is Through hole 1
5, a part of the anisotropic conductive material 43 is emitted from the through hole 1
5 Crawl up, but in this part, heating and pressing tool 50
Since it does not exist, it does not adhere to the tool 50, but rather the adhesive force is strengthened.

[Embodiment 2] FIG. 4 is a view showing another embodiment of the film carrier of the present invention. Of the many through holes 15 provided in the same manner as in Embodiment 1, one is provided near each of the left and right ends. Through holes 15a each having a different shape from the other through holes 15
Is formed and serves as an alignment mark for the film carrier 10. Although the shape of the positioning through hole 15a is formed in a quadrangular shape, it is not particularly limited to this shape, and may be a triangle or another polygon.
Further, the alignment mark can be formed by changing the size of the same circular shape.

As a result, when the wiring terminals 12a of the film carrier 10 and the electrode terminals 22 of the liquid crystal cell 20 are aligned with each other, both can be easily aligned with each other even from the surface on the organic insulating film 11 where there is no wiring pattern. The position of the film carrier 10 can be easily adjusted even with a simple optical device such as a stereoscopic microscope or a magnifying glass.

[Embodiment 3] FIG. 5 is a view showing still another embodiment of the film carrier 10 of the present invention. Of a large number of through holes 15 provided in the same manner as in Embodiment 1, the vicinity of each of the left and right ends is shown. It is characterized in that the alignment mark 13 is provided so as to project in one through hole 15a. As a method of providing the alignment mark 13 so as to project into the through hole 15a, for example, the organic insulating film 1
In order to form the wiring pattern 12 and the wiring terminal 12a after forming the predetermined through holes 15 and 15a in 1, the metal material such as copper is provided on the entire surface by the sputtering method or the vapor deposition method and is patterned by the photography technique. At this time, part of the alignment mark 13 is the through hole 1.
The alignment mark 13 can be formed at the same time as the wiring pattern 12 by patterning so as to project into the 5a.

According to the present embodiment, since the alignment mark is formed by utilizing the through hole for venting air, when the alignment with the electrode terminal group of the liquid crystal cell is performed from the back side of the film carrier 10. It can be done very easily.

[0034]

As described above, according to the film carrier of the present invention, air bubbles do not remain in the cured anisotropic conductive film, and the reliability of the insulation between terminals and the adhesive strength are improved. In addition, some anisotropic conductive material is raised in the through hole in the part where there is no heating / pressurizing tool, which further increases the connection strength and the anisotropic conductive material does not adhere to the heating / pressurizing tool. Since it is not necessary to clean the heating / pressurizing tool every time, productivity is greatly improved.

Further, since the film carrier is provided with a large number of through holes, the solvent for peeling can be easily impregnated into the anisotropic conductive material when the film carrier is peeled off.

Further, by utilizing the through hole provided by the present invention as the alignment mark itself or by projecting the alignment mark into the through hole, the terminals of the film carrier and the liquid crystal cell are connected to each other. There is also a secondary effect that the alignment can be easily performed even from the back surface side on the organic insulating film where there is no metal conductor pattern.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a film carrier of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, showing a step of connecting wiring terminal portions of an example of the film carrier of the present invention.

FIG. 3 is a cross-sectional view taken along the line BB of FIG. 1, showing a step of connecting wiring terminal portions of an example of the film carrier of the present invention.

FIG. 4 is a plan view of another embodiment of the film carrier of the present invention.

FIG. 5 is a plan view of still another embodiment of the film carrier of the present invention.

FIG. 6 is a plan view illustrating an example of a conventional film carrier.

FIG. 7 is a diagram illustrating a connecting step of the wiring terminal portion of FIG.

FIG. 8 is an explanatory plan view of an example of a conventional film carrier.

FIG. 9 is a diagram illustrating a connecting step of the wiring terminal portion of FIG.

[Explanation of symbols]

10 film carrier, 11 organic insulating film, 12 wiring pattern, 12a wiring terminal, 15 through hole, 15a
Through hole, 20 liquid crystal cell, 22 electrode terminal, 30 LS
I, 40 anisotropic conductive film, 42 bubbles, 50 heating and pressing tool.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kohei Adachi, 997 Miyoshi, Nishigoshi-cho, Kikuchi-gun, Kumamoto Prefecture Advanced Display Company

Claims (5)

[Claims] 1. A plurality of wiring patterns are formed on an organic insulating film, the ends of the plurality of wiring patterns are aligned as wiring terminals, and the wiring terminal group is electrically connected to another electrode terminal group. A film carrier that can be
A film carrier in which through holes are provided on both sides of the strip-shaped portion and in the organic insulating film in the gap between the wiring terminals, except for the strip-shaped portion along the alignment direction of the wiring terminals. 2. The film carrier according to claim 1, wherein one of the through holes in the vicinity of both ends in the alignment direction of the wiring terminals is formed in a shape or size different from other through holes. 3. The film carrier according to claim 1, wherein the film carrier has alignment marks formed so as to project inside one of the through holes. 4. A liquid crystal cell in which a liquid crystal material is sandwiched between two insulating transparent substrates having an electrode pattern formed therein, and an electrode terminal group of the electrode pattern is provided at an end portion, and a drive for driving the liquid crystal cell. A liquid crystal display device comprising a circuit, wherein the electrode terminal group of the liquid crystal cell and the terminal of the drive circuit are connected by the film carrier according to claim 1. 5. An electrode terminal group of a liquid crystal cell in which a liquid crystal material is sandwiched between two insulating transparent substrates having an electrode pattern formed thereon, a drive circuit can be connected to the other end, and a wiring terminal can be connected to one end. A method for producing a liquid crystal display in which a plurality of wiring patterns having groups are electrically connected to the wiring terminal group of a film carrier formed on an organic insulating film, wherein the wiring terminals are aligned with the organic insulating film. The film carrier in which through holes are provided between the wiring terminals on both sides of the strip-shaped portion except the strip-shaped portion in the direction so that each terminal of the wiring terminal group and the electrode terminal group of the liquid crystal cell match each terminal. The electrode terminals and the wiring terminals are electrically connected to each other by stacking them via a conductive conductive film, applying a heating and pressing tool to the band-shaped portion where the through hole is not provided and adhering it. And a method for manufacturing a liquid crystal display device, characterized by: