JPH10260421A - Liquid crystal display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid all position shifts between lead terminals of a flexible substrate and electrode terminals of a liquid crystal panel at the time of connection by predicting the rate of the sectorial expansion of the tip parts of the lead terminal part to the right and left due to pressure application and heating and arraying the electrode terminals in a sectorial shape. SOLUTION: The electrode terminals 3A on the glass substrate 2 of the liquid crystal panel are formed in the sectorial shape to the right and left around the center part of the electrode terminal group from the outside to the inside of the glass substrate 2 (a). This shape is determined by finding the rate of sectorial expansion of the tip parts of the lead terminals 6 of the flexible substrate 10 to the right and left by thermocompression bonding in advance. The lead terminals 6 of the flexible substrate 10 are positioned on the electrode terminals 3A of the glass substrate 2 across an anisotropic conductive film and bonded by thermcompression to expand the lead terminals 6 in the sectional shape, so that they are connected to the electrode terminals 3A with good position precision (b). Consequently, almost all horizontal and oblique shifts can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly, to a structure of an electrode terminal portion of a liquid crystal display panel and a lead terminal of a flexible substrate and a method of connecting the same.

[0002]

2. Description of the Related Art A liquid crystal display device mainly comprises a liquid crystal panel formed of a glass substrate or the like, and a flexible substrate formed of a resin film connected around the liquid crystal panel and having a driving IC mounted thereon. When electrically and mechanically connecting the electrode terminals of the liquid crystal panel and the lead terminals of the flexible substrate,
A method is mainly used in which an anisotropic conductive film is stuck on an electrode terminal portion of a liquid crystal panel, a flexible substrate is placed on the electrode terminal portion so as to overlap the lead terminal portion, and pressure and heat are applied by a heater tool. Next, a description will be given with reference to the drawings.

FIG. 2 is a top view of a liquid crystal panel, and FIG. 3 is a cross-sectional view when a lead terminal of a flexible substrate is connected to an electrode terminal of the liquid crystal panel by a heater tool.

Referring to FIG. 2 and FIG. 3, the liquid crystal panel 1
Flexible substrate 10 composed of glass substrate 2, liquid crystal element (not shown), and resin film 4 on which drive IC 7 is mounted
It is mainly composed of An electrode terminal group 13 composed of a plurality of electrode terminals 3 is formed in the peripheral portion of the glass substrate 2. The electrode terminals 13 are flexible on the electrode terminals 3 via an anisotropic conductive film 8 containing conductive particles in an adhesive. The lead terminals 6 of the substrate 10 are aligned, pressurized and heated by the heater tool 9 and connected.

However, according to this connection method, the temperature at the time of heating is higher at the tip of the lead terminal 6 of the flexible substrate than at the inside, so that the electrode terminal 3 and the lead terminal 6 of the flexible substrate become parallel before heating. After being heated at the same pitch, the ends of the lead terminals 6 move left and right after heating, and have a certain angle with respect to the glass substrate. For this reason, the lead terminal 6 may be displaced, may not be connected to the predetermined electrode terminal 3 with high accuracy, and may come into contact with an adjacent electrode terminal, so that the liquid crystal module may not operate normally.

As a countermeasure against such displacement of the lead terminals, the following connection method has been proposed.

In Japanese Patent Application Laid-Open No. Hei 4-287022, terminals are connected to signal lines via diagonal wiring, and at least one pitch of the terminals is made larger than the other pitches, so that the terminals of the signal lines are connected to the drive circuit side. It is said that the reliability of the connection with the terminal is improved.

In Japanese Patent Application Laid-Open No. 4-289824,
By setting the terminal pitch in consideration of the stretching of the base film of the flexible substrate in the pressurization / heating process, it is possible to avoid displacement between the electrode terminal group of the liquid crystal display panel and the lead terminal group of the flexible substrate. doing.

In Japanese Patent Application Laid-Open No. Hei 5-196952,
The flexible film on the electrode portion of the flexible substrate is removed and exposed to avoid the influence of thermal expansion.

In Japanese Utility Model Laid-Open No. 5-87950, a lead terminal from which a flexible film on a flexible substrate is removed and a lead terminal laid on a counterpart substrate are directly joined to each other. By applying an agent and fixing the lead wires directly in a bonded state, the displacement of the terminals due to the expansion of the flexible film during thermocompression bonding and the short circuit between adjacent lead terminals are avoided.

In Japanese Patent Application Laid-Open No. 7-5483, a conductive particle is placed on a circuit board terminal and a lead wire on a flexible board with an anisotropic conductive film interposed therebetween. By applying sufficient pressure to form and applying heating for curing the adhesive after the formation of the wedge state, the flexible film of the flexible substrate is not heated or thermally deformed before being pressed by the pressure bonding head, and the liquid crystal panel is not heated. It is stated that there is no displacement between the terminal and the lead wire of the flexible substrate.

Further, in Japanese Patent Application Laid-Open No. 5-249479, a slit is provided between the lead wires of a flexible substrate to divide the lead wire group, and the accumulated pitch error in forming the lead wire group and the elongation in thermocompression bonding are reduced. By reducing the distance, a displacement between the two is avoided.

[0013]

However, among the above connection methods, Japanese Patent Application Laid-Open Nos. 4-287022 and 4-289824 disclose only the displacement of the terminal portion of the liquid crystal panel and the flexible substrate in the parallel direction. There is a problem that if the parallel lead terminals are obliquely shifted, the shift cannot be solved.

Japanese Unexamined Patent Publication No. Hei 5-196952, Japanese Utility Model Laid-Open No. 5
JP-A-87950 and JP-A-5-249479 disclose removing a carrier tape on a flexible substrate and providing slits between terminals, so that the strength of the flexible substrate alone is reduced and the flexible substrate is manufactured. There is a problem that the number of man-hours for the operation increases.

Japanese Patent Application Laid-Open No. 7-5483 has a problem that a time loss occurs because heating is performed after pressure is applied.

An object of the present invention is to provide a liquid crystal device capable of avoiding any displacement between the electrode terminals of a liquid crystal panel and the lead terminals of a flexible substrate caused by pressurizing and heating when connecting the two. An object of the present invention is to provide a display device and a manufacturing method thereof.

[0017]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: an electrode terminal group comprising a plurality of electrode terminals formed in parallel at one end of a glass substrate of a liquid crystal display panel;
In a liquid crystal display device having a flexible substrate lead terminal aligned on the electrode terminal and connected via an anisotropic conductive film, the plurality of electrode terminals constituting the electrode terminal group are formed of the glass substrate. It is characterized in that it is formed in a fan shape on the left and right with the center of the electrode terminal group as the center from the outside to the inside.

According to a second aspect of the invention, there is provided a method of manufacturing a liquid crystal display device.
An anisotropic conductive film is formed by forming a plurality of electrode terminals, which are formed in parallel at one end of a glass substrate of a liquid crystal display panel to constitute an electrode terminal group, and lead terminals, which are formed in parallel at an equal pitch on a flexible substrate. In a method of manufacturing a liquid crystal display device which is electrically and mechanically connected by thermocompression bonding via a wire, a ratio at which the tip end of the lead terminal expands in a fan shape to the left and right by thermocompression is determined in advance, and the position is determined by thermocompression. A plurality of the electrode terminals constituting the electrode terminal group are provided in a fan shape so as to be connected with high accuracy.

[0019]

According to the present invention, the ratio of the electrode terminals of the liquid crystal panel is arranged in a fan shape by estimating the rate at which the tip of the lead terminal portion of the flexible substrate caused by pressurization and heating expands in the right and left direction. The displacement can be eliminated.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIGS. 1A and 1B are plan views of an end portion of a glass substrate of a liquid crystal panel for describing an embodiment of the present invention. This will be described below with reference to FIGS.

As shown in FIGS. 2 and 3, the liquid crystal display device mainly includes a liquid crystal panel 1 composed of a glass substrate 2 and the like, and a flexible substrate 10 composed of a resin film connected around the liquid crystal panel and having a driving IC mounted thereon. Is configured. Then, the anisotropic conductive film 8 is formed by connecting a plurality of electrode terminals formed in parallel to an end of one side of the glass substrate 2 to form an electrode terminal group and lead terminals 6 formed in parallel on the flexible substrate at an equal pitch. Electrical and mechanical connection by thermocompression bonding via a wire, especially the electrode terminal 3A on the glass substrate 2.
As shown in FIG. 1 (a), are formed in a fan shape on the left and right around the center of the electrode terminal group in a direction from the outside to the inside of the glass substrate 2. This shape is determined in advance by calculating the rate at which the tip end of the lead terminal 6 expands in a fan shape to the left and right by thermocompression bonding. In particular, the arrangement of the electrode terminals 3A is determined by obtaining the angle α of the deviation of the lead terminal at the end.

By positioning the lead terminals 6 of the flexible substrate 10 via the anisotropic conductive film 8 on the electrode terminals 3A on the glass substrate thus configured, and performing thermocompression bonding with the heater tool 9, As shown in FIG. 1B, the lead terminals 6 spread in a fan shape and are connected to the electrode terminals 3A with high positional accuracy. That is, the displacement in the horizontal direction and the oblique direction can be almost eliminated.

In the case of this embodiment, when the width of the flexible substrate is 25 mm and the pressing temperature is 180 ° C., the angle deviation α at both ends of the flexible substrate is 2 degrees. For this reason, the angle of the electrode terminal 3A to which the lead terminal of the liquid crystal panel is connected is set such that the angle α between the electrode terminals at both ends is 0 ° and 2 °, and the angle α is in the range of 0 ° to 2 °. It has a fan-like structure that changes gradually. Since the angle deviation is 0 degree at the terminal at the center of the flexible substrate, the proportional calculation was performed so that the setting of the angle from the center of the electrode terminal group to both ends was 0 degree to 2 degrees. For example, the electrode terminal group 13
Is 240, the angle α of the 60th electrode terminal 3A from the end is 2/240 / (60 × 2) = 1 degree.

[0024]

As described above, according to the present invention, the electrode terminals are formed in a fan shape in advance by determining the rate at which the tip of the lead terminal expands in a fan shape to the left and right by thermocompression bonding.・ The electrode terminals of the liquid crystal panel during heating and the lead terminals of the flexible substrate are connected without displacement,
It is possible to solve the short circuit between the adjacent electrode terminals caused by the displacement of the lead terminal as in the related art. Therefore, the reliability of the liquid crystal display device can be improved, and
It is possible to correspond to fine pitch.

[Brief description of the drawings]

FIG. 1 is a plan view of an end portion of a glass substrate of a liquid crystal panel for describing an embodiment of the present invention.

FIG. 2 is a top view of a liquid crystal panel.

FIG. 3 is a cross-sectional view of an edge portion of a liquid crystal panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Glass substrate 3, 3A electrode terminal 4 Resin film 6 Lead terminal 7 Drive IC 8 Anisotropic conductive film 9 Heating tool 10 Flexible substrate

Claims (2)

[Claims] An electrode terminal group comprising a plurality of electrode terminals formed in parallel at one end of a glass substrate of a liquid crystal display panel, and an electrode terminal group positioned on the electrode terminals via an anisotropic conductive film. In a liquid crystal display device having a lead terminal of a flexible substrate connected thereto, the plurality of electrode terminals constituting the electrode terminal group are centered on the center of the electrode terminal group in a direction from the outside to the inside of the glass substrate. A liquid crystal display device formed in a fan shape on the left and right. 2. A liquid crystal display panel comprising a plurality of electrode terminals formed in parallel at one end of a glass substrate of a liquid crystal display panel and constituting an electrode terminal group and lead terminals formed in parallel at an equal pitch on a flexible substrate. In a method of manufacturing a liquid crystal display device which is electrically and mechanically connected by thermocompression bonding via an isotropic conductive film, a ratio in which the tip of the lead terminal expands in a fan shape to the left and right by thermocompression is determined in advance. A method of manufacturing a liquid crystal display device, wherein a plurality of electrode terminals constituting the electrode terminal group are provided in a fan shape so as to be connected with good positional accuracy by thermocompression bonding.