JPH0572551A - Terminal connecting method for display element - Google Patents

Abstract

PURPOSE:To improve the reliability of connection by disposing anisotropic conductive films only in electrode terminal parts facing each other and disposing flexible adhesives of an acrylic system in the spacings between the electrode terminals. CONSTITUTION:After the anisotropic conductive films 3 are disposed for each of the respective display element electrode terminals 2 led out of the sealing part of a display element substrate 1, the flexible adhesives 6 thicker than the thickness of the anisotropic conductive films 3 are disposed in the spacings between the respective adjacent display element electrode terminals 2. The flexible adhesives 6 consist of the materials of the acrylic system which have high insulation resistance and are thermoset at the time of heating and compression bonding. On the other hand, a flexible printed circuit board 4 disposed with flexible printed circuit board electrode terminals 5 of the same shape at the intervals equal to the intervals of the display element electrode terminals 2 is subjected to heating and pressing after the alignment of the respective electrode terminals 2, 5, by which the anisotropic conductive films 3a having an electrical conductivity are formed between the display element electrode terminals 2 and the flexible printed circuit board electrode terminals 5 facing each other. The flexible adhesives 6 are packed between the adjacent anisotropic conductive films 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting terminals of a display element, and more particularly to a method of connecting terminals of a display element connected by an anisotropic conductive film.

[0002]

2. Description of the Related Art In recent years, a flexible printed circuit board has been used for the purpose of thinning a display element and simplifying a device assembly process of the display element.

A method of connecting the display element electrode terminal and the flexible printed circuit board electrode terminal is derived from a seal portion (not shown) of the display element substrate 1 as shown in the sectional structure before connection in FIG. 3 (a). An orthogonal tape-shaped anisotropic conductive film 3 is arranged on the display element electrode terminal 2 and pre-pressurized, and then the flexible substrate electrode terminal 5 of the flexible printed board 4 and the display element electrode terminal 2 of the display element substrate 1 are arranged. After aligning each other with each other, by heating and pressure bonding, as shown in FIG.
As shown in (b) the cross-sectional structure after the connection, the anisotropic conductive film disposed between the respective electrode terminals 2 and 5 is heated and pressure-bonded, and the internal conductive material (solder or nickel) is mutually bonded. On the other hand, the anisotropic conductive film 3a other than the electrode terminals 2 and 5 does not have the same conductivity, and only the electrode terminals 2 and 5 are electrically connected.

[0004]

In the conventional method of disposing the anisotropic conductive film 3 also between the flexible printed circuit board 4 and the adjacent electrode terminals 5 and 2 of the display element substrate 1, the opposing electrodes 2 and 5 are arranged. When the thickness between the electrode terminals 2 and 5 of which the anisotropic conductive film 3 and the anisotropic conductive film 3a itself between the adjacent electrode terminals 2 and 5 which protrude from the space are opposed to each other, in particular, the insulating characteristics are opposed to each other, is small. The anisotropic conductive film 3 is pressed against the entire surface to deteriorate the insulation characteristics, increase the leakage between the adjacent electrode terminals 2 and 5, and heat between the opposing electrode terminals 2 and 5,
There are restrictions on connection strength, working conditions, and electrode terminal structure, such as an increase in connection resistance due to insufficient crimping, and there is a problem in connection reliability.

In particular, this problem is remarkable in an electroluminescence display or a plasma display which operates as a display element under the conditions of high voltage and large current.

An object of the present invention is to provide a terminal connection method for a display element having high connection reliability.

[0007]

SUMMARY OF THE INVENTION The present invention is a display element in which a display element electrode terminal and one of the external electrode terminal and the flexible printed circuit board electrode terminal are connected by an anisotropic conductive film. In the method of connecting terminals described above, a flexible adhesive having a thickness of the anisotropic conductive film, which has been supplied on the display element electrode terminals in advance, is disposed between the display element electrode terminals and pressure-bonded to the display element. Any one of the element electrode terminal, the external electrode terminal, and the flexible printed board electrode terminal is conductively connected by the anisotropic conductive film.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a partially enlarged perspective view of a display element electrode terminal portion according to an embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views showing a sequence of steps for explaining the embodiment of the present invention. is there.

As shown in FIG. 1, after the anisotropic conductive film 3 is arranged for each display element electrode terminal 2 led out from the seal portion 7 of the display element substrate 1, a gap between adjacent display element electrode terminals 2 is provided. Flexible adhesive 6 thicker than the thickness of anisotropic conductive film 3
To place. This flexible adhesive 6 has high insulation resistance,
It is made of an acrylic material that is thermoset when heated and pressed.

On the other hand, as shown in FIG. 2 (a), the flexible printed circuit board 4 on which the flexible printed circuit board electrode terminals 5 of the same shape as the display element electrode terminals 2 are arranged at equal intervals.
After the alignment of the respective electrode terminals 2 and 5,
As shown in FIG. 2 (b), a conductive anisotropic substance is applied between the display element electrode terminal 2 and the flexible printed circuit board electrode terminal 5 which are opposed to each other by heating and pressurizing under the conditions of ℃, 45 Kg / cm ₂ and 20 seconds. A flexible conductive film 3a is formed, and a flexible adhesive 6 having a high insulation resistance is filled between adjacent anisotropic conductive films 3a to obtain a highly reliable connection structure.

[0012]

As described above, according to the present invention, an acrylic flexible adhesive having a good insulating property is provided only in the electrode terminal portion for connecting the anisotropic conductive film, and the gap between the electrode terminals is good. Since the electrodes are arranged, the connection between the opposite electrode terminals is good, the protrusion of the anisotropic conductive film from the electrode terminal portion is small, and the gap between the adjacent electrode terminals is filled with the acrylic flexible adhesive. As a result, there is no deterioration of insulation resistance between adjacent electrode terminals. Moreover, the acrylic flexible adhesive material also reinforces the adhesion between the display element substrate and the flexible printed circuit board, and has sufficient connection strength only by heating and crimping work, and the conventional post-reinforcement finishing process is also omitted. There is an effect that extremely effective terminal connection can be obtained.

[Brief description of drawings]

FIG. 1 is a partially enlarged perspective view of a display element electrode terminal portion according to an embodiment of the present invention.

2A to 2D are cross-sectional views showing a process sequence for explaining an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional method of connecting terminals of a display element, which is shown in the order of steps.

[Explanation of symbols]

 1, 1a Display element substrate 2 Display element electrode terminal 3, 3a Anisotropic conductive film 4 Flexible printed circuit board 5 Flexible printed circuit board electrode terminal 6 Flexible adhesive 7 Seal part

Claims (1)

[Claims] 1. A terminal connection method for a display element, comprising: connecting a display element electrode terminal and one of the external electrode terminal and the flexible printed circuit board electrode terminal with an anisotropic conductive film. A flexible adhesive having the thickness of the anisotropic conductive film, which has been supplied in advance on the display element electrode terminals, is placed between the display element electrode terminals and pressure-bonded to the display element electrode terminals and the external electrode terminals. A terminal connection method for a display element, characterized in that one of the electrode terminals of the flexible printed circuit board and the electrode terminal of the flexible printed circuit board is electrically connected by the anisotropic conductive film.