JPH02267876A - Electrode terminal connection structure - Google Patents

Abstract

PURPOSE:To avoid reduction in connecting reliability due to reduced insulation resistance between adjacent terminals by dust and dirt adhering to an anisotropic conductive film which is caught between two opposed electrodes in a connecting portion by allowing the electrode terminals for connecting the ends of the anisotropic conductive adhesive film to extend past the connecting portion in their vicinity. CONSTITUTION:When electrode terminals are connected to each other for electrical connection with the use of an anisotropic conductive adhesive film 1, the ends 1A, 1B of the conductive adhesive film are allowed to extend past the connecting portion where electrode terminals 3, 4 overlap each other, there by avoiding reduction in connecting reliability and electrical resistance between the adjacent electrode terminals due to dust and dirt adhering to the ends of the conductive adhesive film 1 and which is caught between the electrode terminals 3, 4. Also, removing the end of the conductive adhesive film 1 extending past the portion where the electrode terminals 3, 4 are connected after they have bean connected to each other helps to provide an effective means of avoiding reduction in insulation resistance between the adjacent terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrode terminal connection structure in which electrode terminals are electrically connected using an anisotropic conductive adhesive film.

[Prior Art] In recent years, conductive particles have been incorporated into insulating adhesives for circuit connections between display elements and wiring boards using liquid crystal, EL, plasma, or fluorescent displays, and for circuit connections between integrated circuits and wiring boards. A connection structure using a dispersed anisotropic conductive adhesive film is used. This has come to be used as a circuit connection structure as the pitch of connection terminals has become narrower and the number of connection terminals has increased, and it has conductivity only in the thickness direction between opposing circuits to be connected. This is realized by a method of sandwiching such anisotropic conductive adhesive films and performing connection by means including pressure.

FIG. 4 shows a conventional circuit connection structure using an anisotropic conductive adhesive film. In the figure, 1 is an anisotropic conductive adhesive film, 2 is a glass substrate of a liquid crystal display element, and 3 is on a glass substrate 2. 4 is an extraction electrode terminal of an external circuit electrically connected to the extraction electrode terminal 3 via anisotropic conductive adhesive 811; 5 is a support member for the extraction electrode terminal 4; It is.

[Problems to be Solved by the Invention] Incidentally, in such a conventional connection structure, the anisotropic conductive adhesive film is formed into a tape or strip shape with a width corresponding to the width of the overlap of opposing terminals to be connected. used. When such molding is performed, even if one or both sides of the anisotropic conductive adhesive film is covered with a separator to prevent dust from entering the film, when cutting the anisotropic conductive adhesive film into a tape or strip shape, Dust that is generated tends to adhere to the cut end of the anisotropic conductive adhesive film. Furthermore, when placing an anisotropic conductive adhesive film on one of the opposing terminals to be connected, the ends of the anisotropic conductive adhesive film are always exposed to the outside during or after the process. Since it is exposed, it is easily contaminated with dust, moisture, oil, solvents, etc.

When an anisotropic conductive adhesive film with dust attached or contaminated ends is used in a conventional connection structure as shown in Fig. 4, the insulation resistance between terminals or There were the following problems in terms of insulation reliability, etc.

In other words, at the connection between opposing terminals that are connected by means such as applying pressure or heating, dust adhering to the edges of the anisotropic conductive adhesive film causes a decrease in insulation resistance between adjacent terminals. Put it away.

Further, dust causes uneven distribution of conductive particles existing between adjacent terminals, and agglomeration of the conductive particles causes a decrease in insulation resistance between adjacent terminals. Furthermore, there is a problem in that contamination of the ends of the anisotropic conductive adhesive film lowers the insulation reliability between adjacent terminals and lowers the connection reliability between opposing terminals.

In view of the above-mentioned problems with the conventional type, the present invention avoids a decrease in insulation resistance between adjacent terminals and a decrease in connection reliability caused by dust or contamination at the edge of an anisotropic conductive adhesive film. The purpose of the present invention is to provide a connection structure for electrode terminals that can be connected to an electrode terminal.

[Means and effects for solving the problem] In order to achieve the above object, the present invention provides an edge portion of an anisotropic conductive adhesive film,
The opposing terminals to be connected are located outside the overlapping connection portion. This can prevent dust and dirt attached to the ends of the anisotropic conductive adhesive film from being caught between opposing terminals.

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic partial sectional view showing an electrode terminal connection structure according to an embodiment of the present invention, and FIG. 2 is a plan view thereof. FIG. 1 shows a cross section taken along the line X-x in FIG. 2.

In these figures, 1 is an anisotropic conductive adhesive film, 2 is a glass substrate of a liquid crystal display element, 3 is an extraction electrode terminal of a liquid crystal display element formed on the glass substrate 2, and 4 is an anisotropic conductive adhesive film 1. 5 is a base film of the TAB film which is a supporting member of the extraction electrode terminal 4.

In this embodiment, the ends IA and IB of the anisotropic conductive adhesive film 1 are exposed outside the connection portion where the electrode terminals 3 and 4 overlap. Therefore, it is possible to avoid a decrease in insulation resistance between adjacent electrode terminals and a decrease in connection reliability due to dust and dirt attached to the ends of the anisotropic conductive adhesive film 1 being sandwiched between the electrode terminals 3 and 4. can.

Furthermore, removing the ends of the anisotropic conductive adhesive film 1 protruding from the connection portion of the terminal 3.4 after connection is an effective means for avoiding a drop in insulation resistance between adjacent terminals. It is.

The specifications of the TAB film, glass wiring board, and anisotropic conductive adhesive film used in this example are shown below.

TAB film specifications Base film: Polyimide film 75μm External electrode pattern: Electrolytic copper foil 35μm Ni plating 0
．． 5μm Au plating 0.5μm 240μ heavy pitch 80 rye glass wiring board specifications Glass substrate: Blue plate glass 1.1mm thickness External electrode pattern: ITO sheet resistance 20Ω 240μm pitch Anisotropic conductive 1 coated film specifications Adhesive: Thermosetting epoxy resin Conductive particles: Low melting point metal particles In this example, the TAB film and the glass wiring board were connected by thermocompression bonding with the end of the anisotropic conductive adhesive film positioned so as to protrude 0.5 m+a from the electrode terminal connection part. went.

A comparison between this embodiment and a conventional example regarding the frequency of occurrence of current leakage between adjacent terminals after connection is shown below.

Note that the present invention is applicable to all connection structures in which opposing electrode terminals are connected by an anisotropic conductive adhesive film.

[Another Embodiment] FIG. 3 is a schematic sectional view showing a connection structure of electrode terminals according to another embodiment of the present invention.

In the figure, 1 is an anisotropic conductive adhesive film, 7 is an output electrode terminal for connecting an external circuit to a printed wiring board, 4 is an output electrode terminal for a flexible wiring board for an external circuit, 6 is a support member for the electrode terminal 7, 8 is an insulating paint, and 5 is a support member for the electrode terminal 4.

In the connection structure of this embodiment, the end portion of the anisotropic conductive adhesive film 1 is exposed to the outside of the connection portion where the electrode terminal 7 and the electrode terminal 4 are close to each other. This prevents a decrease in insulation resistance between adjacent electrode terminals and a decrease in connection reliability due to dust and dirt attached to the ends of the anisotropic conductive adhesive film 1 being sandwiched between the electrode terminals 3 and 4. can.

[Effects of the Invention] As explained above, according to the present invention, the ends of the anisotropic conductive adhesive film are exposed to the outside of the connection portion adjacent to the picture electrode terminal to be connected, so that the anisotropic It is possible to avoid a decrease in insulation resistance between adjacent terminals and a decrease in connection reliability due to dust or dirt adhering to the end of the conductive film being caught between opposing electrodes of the connection portion.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a connecting part between a liquid crystal panel lead-out electrode terminal and an electrode terminal to an external circuit according to an embodiment of the present invention, FIG. 2 is a plan view of the connection structure of the above embodiment, and FIG. The diagram is
FIG. 4 is a cross-sectional view of a connecting portion between a printed wiring board and a flexible wiring board according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of a connecting portion of a conventional example. DESCRIPTION OF SYMBOLS 1: Anisotropic conductive adhesive film, 2: Glass substrate of liquid crystal display element, 3: Leading electrode terminal of liquid crystal display element, 4: Leading electrode terminal of external circuit, 5: Supporting member of leading electrode 4.

Claims (1)

[Claims] (1) An anisotropic conductive adhesive film made of conductive particles dispersed in an insulating adhesive is interposed between opposing electrode terminals,
In the connection structure in which the electrode terminals are connected to each other by bringing them close to each other, an end portion of the anisotropic conductive adhesive film is located outside the connection portion where the opposing electrode terminals overlap, A connection structure for electrode terminals using an anisotropic conductive adhesive film, characterized in that opposing electrode terminals are brought close to each other.