JPH04301622A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent the leakage of currents between connecting terminals and dislocation by providing passivation layers of the height equal to or larger than the height of terminal electrodes disposed on a liquid crystal display panel on both sides of these terminal electrodes. CONSTITUTION:Each of the terminal electrodes 2 which are led out of the picture element electrodes disposed on the surface of the liquid crystal display panel 1 is formed with the passivation layers consisting of SiO2 so as to hold the terminal electrodes 2 in-between on both sides of the terminal electrodes 2. The terminal electrodes 2 and the terminal electrodes 4 of the substrate 3 mounted with an IC for driving are connected to each other via an anisotropic conductive adhesive 6. Namely, the signals from the IC for driving are transmitted from the wirings of the substrate 3 to the terminal electrodes 4 and further to the terminal electrodes 2 of the liquid crystal display panel 1 and to the picture elements to display the liquid crystal panel. The signal currents do not leak between the connecting terminals and the dislocation between the connecting terminals is suppressed. Short circuiting is thus prevented.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a liquid crystal display device that can reliably connect terminal electrodes arranged on a liquid crystal display panel and terminal electrodes arranged on a substrate mounted with a driving IC. .

0002

[Prior Art] Among thin flat display devices, flat display devices using liquid crystals have been developed for a wide range of applications, from ultra-small micro-sized to ultra-large high-definition devices, due to the diversification of industrial equipment in recent years. being done. It is also used as a display device for television receivers, OA equipment, or video equipment. In particular, a high-resolution liquid crystal display device must be realized in order to be used as a display device for video equipment. In order to configure a high-resolution liquid crystal display device, the number of signal lines within the liquid crystal display device is increased, and the number of pixels is also increased, thereby realizing a high-resolution liquid crystal display device. As the number of pixels increases and the number of signal lines increases in this way, it becomes necessary to increase the number of terminal electrodes arranged on the liquid crystal display panel, increase the density of the arrangement pitch, and furthermore make the terminal electrodes finer. It is something. However, as the number of terminal electrodes increases, the arrangement pitch becomes higher density, and the terminal electrodes become finer, the terminal electrodes manufactured to correspond to the terminal electrodes of the liquid crystal display panel of the substrate mounted with the driving IC and the liquid crystal Leakage of signal current for driving the liquid crystal display panel at the connection portion with the terminal electrode of the display panel causes a significant deterioration in display image quality. Furthermore, short circuits due to misalignment between terminal electrodes that are to be connected to each other can also be considered a major problem.

[0003] A method of connecting the terminal electrodes of a conventional liquid crystal display panel and the terminal electrodes of a substrate mounted with a driving IC (hereinafter referred to as O
As shown in FIGS. 4 and 5, the terminal electrode 4 of the substrate 3 on which the driving IC 7 is mounted is placed directly opposite the terminal electrode 2 formed on the liquid crystal display panel 1. It was thermocompression bonded to the liquid crystal display panel 1 via a conductive adhesive 6, and electrical conductivity between the terminal electrodes 2 and 4 was ensured by the conductive agent 5 contained in the anisotropic conductive adhesive 6. With this method, the output signal from the driving IC 7 is transmitted from the wiring of the substrate 3, through the terminal electrode 4, through the conductive agent 5, and the terminal electrode 2, and then reaches the liquid crystal display panel 1.

0004

[Problems to be Solved by the Invention] However, in conventional OLBs, the terminal electrodes were simply placed directly opposite each other and connected via anisotropic conductive adhesive, so as the terminal electrodes became finer and more dense, the connecting terminals It becomes difficult to prevent signal current leaks and short circuits between the two. Therefore, there is a problem in that the display image quality of the liquid crystal display panel is significantly degraded.

An object of the present invention is to provide a liquid crystal display device that solves the above-mentioned problems.

[0006]

Means for Solving the Problems In order to achieve the above object, there is provided a device comprising a liquid crystal display panel and a substrate mounted with a driving IC for driving the liquid crystal display panel, the device comprising: a liquid crystal display panel; A passivation layer having a height equal to or higher than that of the terminal electrode is provided on both sides of each terminal electrode arranged above, and the terminal electrode and the terminal electrode arranged on the substrate are bonded with an anisotropic conductive adhesive. It is characterized by being connected by.

[0007]

[Embodiment] (Embodiment 1) Figs. 1 and 2 are main sectional views showing a first embodiment of the present invention, and in Figs. 1 and 2,
1 is a liquid crystal display panel, 2 is a terminal electrode arranged on the liquid crystal display panel 1, 3 is a substrate mounted with a driving IC 7, 4 is a terminal electrode arranged on the substrate 3, 6 is an anisotropic conductive adhesive, Reference numeral 5 indicates a conductive agent contained in the anisotropic conductive adhesive 6, and 8 indicates a passivation layer.

In the embodiment of the present invention, as shown in FIGS. 1 and 2, for each terminal electrode 2 made of ITO drawn out from a pixel electrode arranged on the surface of a liquid crystal display panel 1,
A passivation layer 8 made of SiO2 is formed on both sides of the terminal electrode 2 so as to sandwich the terminal electrode 2, and the terminal electrode 2 and the driving IC 7 are attached to the terminal electrode 3 via an anisotropic conductive adhesive 6. 4 was connected. With this configuration, the signal from the driving IC 7 is transmitted from the wiring of the substrate in the order of the terminal electrode 4 → the conductive agent 5 → the terminal electrode 2 → the pixel, and the display on the liquid crystal display panel 1 is performed.

The first embodiment will be explained in detail with reference to FIGS. 1 and 2. A pixel electrode and a terminal electrode 2 made of ITO were patterned to a thickness of 8000 Å on a glass substrate kept clean using photopatterning technology. At this time,
The width of the terminal electrodes 2 was set at a pitch of 100 μm. Furthermore, a height of 12000 Å and a width of 10 μm is provided on both sides of the terminal electrode 2.
The passivation layer 8 was formed of SiO2. Next, using the glass substrate as an element substrate and a counter substrate manufactured elsewhere, a liquid crystal display panel 1 was fabricated through a panel assembly process. Note that, for example, the passivation layer 8 can be formed simultaneously with the formation of the TFT electrode during the TFT substrate formation process. Next, a pattern having terminal electrodes 4 with a pitch of 100 μm is formed on a flexible substrate made of polyimide as a base material, and a driving I
C7 was mounted to form a driving board 3. After temporarily press-bonding the anisotropic conductive adhesive 6 to the terminal electrodes 4 of the substrate 3 on which the driving IC 7 is attached, align the terminal electrodes 4 with the terminal electrodes 2 of the liquid crystal display panel 1, and ensure sufficient alignment. A directional conductive adhesive 6 was thermocompression bonded to the panel 1 and the substrate 3 to connect both terminal electrodes 2 and 4 to each other. At this time, the anisotropic conductive adhesive 6
The conductive material 5 contained in the terminal electrodes 2 and 4 is crushed by heat and pressure to maintain continuity between the terminal electrodes 2 and 4. Further, the connection between the terminal electrodes 2 and 4 is maintained by the adhesive force of the anisotropic conductive adhesive 6. With this configuration, the signal from the driving IC 7 is transmitted from the wiring of the substrate 3 to the terminal electrode 4, further to the terminal electrode 2 of the liquid crystal display panel 1, and then to the pixel, and display on the liquid crystal display panel 1 is performed. However, the signal current is transmitted without leakage occurring between the connection terminals. Furthermore, positional deviations between the connection terminals can also be minimized.

(Embodiment 2) A second embodiment will be explained based on FIG. 3. In FIG. 3, 1 is a liquid crystal display panel, 2 is a terminal electrode arranged on the liquid crystal display panel 1, and 3 is a driving IC.
7 is attached to the board, 4 is the terminal electrode arranged on the board 3, 6
indicates a conductive adhesive, and 5 indicates a conductive agent contained in the conductive adhesive 6. In the second example, terminal electrodes 2 having a thickness of 10,000 Å and a pitch of 120 μm were formed using ITO on the surface of a glass substrate. Next, a passivation layer 8 having a height of 14 μm and a width of 5 μm was formed from SiO2 adjacent to the outside of the terminal electrode 2, and then a liquid crystal display panel 1 was constructed using the glass substrate through a panel assembly process. Next, a conductive adhesive 6 is temporarily pressed onto the terminal electrode 4 of the flexible substrate 3 on which the driving IC 7 designed and manufactured so as to directly face the terminal electrode 2 on the panel 1 is mounted, and the terminal electrode 4 is attached to the terminal electrode 4. After alignment with the electrode 2, a thermocompression bonding machine was used to press the conductive adhesive 6 onto the panel 1 and the substrate 3, thereby connecting the terminal electrodes 2 and 4 to each other. By providing the passivation layer 8 on both sides of the terminal electrode 2 in this manner, leakage between the connection terminals does not occur, and misalignment between the connection terminals can also be prevented.

[0011]

Effects of the Invention As described above, the present invention provides a passivation layer on both sides of each terminal electrode arranged on a liquid crystal display panel, which has a height equal to or higher than that of the terminal electrode. By using an anisotropic conductive adhesive to connect the terminal electrodes arranged on the board and the terminal electrodes arranged on the board mounted with the drive IC for driving the liquid crystal display panel, the connection between each connection terminal is achieved. Current leakage can be prevented. Furthermore, it has the advantage that a high level of image quality can be obtained because positional deviation between terminals is prevented and short circuits do not occur.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal display device showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the same embodiment.

FIG. 3 is an enlarged sectional view of a liquid crystal display device showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a conventional liquid crystal panel for explaining a conventional liquid crystal display panel connection method (OLB).

FIG. 5 is an enlarged sectional view of the conventional liquid crystal panel.

[Explanation of symbols]

1 Liquid crystal display panel 2 Terminal electrodes arranged on the liquid crystal display panel 3 Substrate 4 on which the driving IC is mounted Terminal electrodes 5 arranged on the substrate on which the driving IC is mounted
Conductive agent contained in anisotropic conductive adhesive 6 Anisotropic conductive adhesive 7 Drive IC 8 Passivation layer

Claims (3)

[Claims] 1. A device consisting of a liquid crystal display panel and a substrate mounted with a driving IC for driving the liquid crystal display panel, wherein terminal electrodes are provided on both sides of each terminal electrode arranged on the liquid crystal display panel. , a liquid crystal characterized in that a passivation layer having a height equal to or higher than the terminal electrode is provided, and the terminal electrode and the terminal electrode arranged on the substrate are connected by an anisotropic conductive adhesive. display device. 2. The width of the passivation layer is 10% to 20% of the width of the terminal electrodes arranged on the liquid crystal display panel.
2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is configured within the range of . 3. The liquid crystal display device according to claim 1, wherein the passivation layer is formed during the TFT substrate forming process at the same time as forming the TFT electrode.