JPS6067984A - Electrode terminal pick up construction of flat display panel - 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] Technical Field> The present invention relates to a structure for taking out electrode terminals in a display panel, and is a technology that is particularly effective for flat display panels that require multi-terminal takeout such as matrix electrode structures. It is.

<Prior art> Flat display panels such as thin-film EL panels, liquid crystal display panels, and plasma display panels generally have a large number of terminals for taking out electrodes at a fine pitch around the panel substrate. The connecting bottle is connected to an FPC (flexible printed circuit board) formed by patterning copper foil or the like on a polyimide film by adhesion using conductive paste or hot melt, or pressure bonding using conductive elastomer. That is, in order to respond quickly to the diversification of information, the display electrodes of these flat display panels are generally configured with an X-Y matrix electrode structure, and a dot matrix type display is performed. .

Therefore, in order to clearly display a large amount of information, it is necessary to arrange the number of drive electrode lines at a high density, and the number of terminals for taking out the electrodes inevitably increases.

However, when using a bottle to measure the number of terminals, it becomes difficult to manufacture the bottle as the arrangement pitch of the electrode terminals becomes finer, and the strength of the bottle itself becomes weaker. As the pressure increases, a large pressing force is required and it is necessary to make the pressing force uniform, resulting in an increase in the size of the pressing mechanism, and both pose problems in manufacturing. Therefore, when extracting a large number of terminals from small bits, use F.
A method of bonding by combining PC and a resin material such as fusion bonding with solder or conductive paste or hot melt is widely used. In this method, since the electrode lead-out terminal formed on the panel substrate is a thin film or a thick film, it is generally protected with a resin coating from the viewpoint of moisture resistance or improving mechanical strength. However, with this protective structure, thin film EL panels etc. use glass substrates as panel substrates, and the coefficient of thermal expansion is 3~3.
Due to its small temperature of 5xio' ℃-1, protective resin and 1
This means that there is a difference of several orders of magnitude, and large stress acts between the panel substrate and the protective resin due to the temperature difference between the resin's curing temperature and room temperature or temperature changes in the usage environment, resulting in resin peeling or Defects such as glass cracks may occur.

Further, under the influence of this stress, a problem arises in that corrosion of the terminal for taking out the electrode is accelerated. Further, since it is necessary to relieve stress and the layer thickness of the resin cannot be increased, the prevention of moisture penetration is incomplete and a sufficient moisture resistance effect cannot be obtained.

FIG. 1 is a configuration diagram of an electrode terminal extraction portion in a conventional thin film EL display panel. The glass substrate 1 and the rear glass plate 2 constitute an envelope of the display panel, and a thin film EL is installed inside this envelope.
Element 3 is enclosed. A thin film EL element has a matrix electrode structure formed on the display side and the back side, and by selectively applying an alternating current voltage, the E
The L light is emitted and a light emitting display is performed through the glass substrate 1. Display electrodes constituting the matrix electrode are arranged on the glass substrate l, and these display electrodes extend outward from the envelope and are made of A/film and Ni film that are continuously formed up to the periphery of the glass substrate l. It is connected to an electrode extraction terminal 4 having a two-layer structure.

An FPC 5 is connected to the terminal 4 by solder 6, and the upper surface of the glass substrate l including this connection portion is coated with resin 7. This resin 7 constitutes the moisture-resistant protective structure described above, but since the resin 7 has a large surface area that comes into contact with air,
It has a structure that is easily impregnated with moisture in the air, and in this respect also has the disadvantage of insufficient moisture resistance.

<Object of the Invention> The present invention prevents the resin layer from peeling off by using a structure in which the moisture-resistant resin layer coated on the terminal portion for taking out the electrode is sandwiched between glass, glass members, etc. having similar coefficients of thermal expansion. Another object of the present invention is to provide a novel and useful electrode terminal extraction structure for a flat display panel that has further improved moisture resistance.

<Embodiment> FIG. 2 is a diagram showing the main part of an electrode terminal extraction structure of a thin film EL display panel showing one embodiment of the present invention.

Similarly to FIG. 1, a glass substrate 1 and a rear glass plate 2 constituting an envelope of a thin film EL display panel are stuck together with a sealant, and a thin film EL element 3 is housed in the internal gap. Thin film E
Electrode wires constituting the matrix electrode structure of the L element 3 extend outward from the envelope and are connected to electrode extraction terminals 4 arranged on the peripheral edge of the glass substrate 1. An end portion of an FPC 5 made of polyimide film or the like is bonded to the terminal 4 with solder 6. The FPC 5 has metal lead wires such as copper foil arranged on a base film at the same pitch as the terminals 4. Electrical connection is made by bringing these metal lead wires into contact with the terminals 4 and fixing them. A power feeding path to the element 3 is formed. The upper surface of the glass substrate 1 including the connecting portion between the terminal 4 and the FPC 5 is coated with a resin 7. A predetermined amount of resin 7 is applied using a dispenser.

A protective glass plate 8 is placed on this resin 7. The protective glass plate 8 is made of a material whose coefficient of thermal expansion is similar to that of the glass substrate 1 of the envelope, but is made of a material other than glass that is rigid, has a small moisture permeability coefficient, and has a coefficient of thermal expansion similar to that of the glass substrate 1. Ceramic or the like may also be used.

In this embodiment, the resin 7 is sandwiched between a protective plate made of a protective glass plate 8 and a glass substrate l. After the protective glass plate 8 is placed, the resin 7 is extended to the edge of the glass substrate 1 by applying pressure from above, and then the resin 7 is cured to complete the protective structure. Note that the resin 7 may be poured between the protective glass plate 8 and the glass substrate 1 using capillary action after the protective glass plate 8 is placed.

As the curing treatment for the resin 7, room temperature curing treatment, heat curing treatment, ultraviolet curing treatment, etc. are applied.

In the above protective structure, the resin 7 and the FPC 5 are sandwiched between the glass substrate l and the protective glass plate 8, which have similar coefficients of thermal expansion, and thermal stress deformation is regulated from both the upper and lower directions. Thermal stress is absorbed by expansion and contraction of volume in the direction parallel to the surface of the glass substrate 1, and as a result, the stress acting on the terminal 4 can be reduced, and at the same time, peeling of the resin 7 and cracking of the glass substrate 1 can be prevented. can. Also, resin 7
Since the upper surface of the device is covered with the protective glass plate 8, the surface area in contact with the air is reduced, the probability of moisture in the air entering is reduced, and the path of moisture permeation becomes longer. Therefore, corrosion of the terminal 4 is effectively prevented.

Display panels having the structure shown in FIG. 1 and the structure shown in FIG. 2 were manufactured, using an ultraviolet curing resin as the resin 7, and
The table below shows the results of a humidity test conducted by leaving the sample in a 95% RH atmosphere.

From the table above, it is recognized that the moisture-resistant protective structure of this example is very excellent.Although the above *example describes a thin film EL display panel, the present invention is applicable to other liquid crystal display panels and plasma display panels. As explained in detail above, according to the present invention, peeling of the resin layer at the terminal portion for taking out the electrodes is prevented and moisture intrusion is also significantly suppressed, so that the moisture-resistant protective structure can be made even more complete. It is possible to do this.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an electrode terminal extraction portion in a conventional thin film EL display panel. FIG. 2 is a diagram illustrating a main part of an electrode terminal extraction structure of a thin film EL display panel showing one embodiment of the present invention. 1...Glass substrate, 2...Back glass plate, 3.
...Thin film EL element, 4...Terminal, 5...FPC
. 6... Solder, 7... Resin, 8... Protective glass plate.

Claims (1)

[Claims] (1) In a flat display panel in which terminals connected to display drive electrodes are arranged around the substrate, a flexible wiring board is connected to the terminals, and resin is filled around the substrate including the connecting portion.1. An electrode terminal extraction structure for a flat display panel, characterized in that a protective plate having a coefficient of thermal expansion similar to that of the substrate is fixed onto the resin.