JPH05191008A - Anisotropic conductor film connection terminals - Google Patents

Abstract

PURPOSE:To ensure the reliability in connection, and o arrange in fine pitch even when the width of connection terminals is small by suppressing the flow out of conductor material from between the connector terminals connected by an anisotropic conductive bonding agent. CONSTITUTION:In the title anisotropic conductor film connection terminals which are electrically connected by an anisotropic conductive film using a conductor material 6 by applying pressure and heat between the connection terminals 1 and 4 which are opposingly arranged with an anisotropic conductive bonding agent 5 interposed between them, the flowing out of the conductive material 6, contained in the anisotropic conductive bonding agent 5, is suppressed by the recesses and protrusions on the surface which is formed by roughing at least the surface of one of the connection terminals 1 and 4 which are opposingly arranged when pressure is applied between the connection terminals. Besides, as the conductor material 6 between connection terminals 1 and 4 is ensured, a complete connection is conducted, and the reliability of connection can be improved. At the same time, the width of the connection terminal can be made small, and the formation of fine pitch can also be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of an anisotropic conductive film connection terminal for conductive connection between connection terminals using an anisotropic conductive adhesive which is mainly used for electronic devices having a small and thin shape. It is a thing.

[0002]

2. Description of the Related Art In electronic equipment such as a calculator, which is required to be thin, for example, the connection between a liquid crystal display and a circuit board is required to be thin, and soldering and lead wire drawing are also restricted. Therefore, the connection between the connection terminals by the anisotropic conductive adhesive is adopted. As shown in FIG. 3, the liquid crystal display 11
The connection terminals 12 provided on the circuit board 13 and the connection terminals 14 provided on the circuit board 13 are arranged facing each other, and the anisotropic conductive adhesive 15 is applied to the joint portion between the liquid crystal display 11 and the circuit board 13. By pressing the circuit board 13 and the liquid crystal display body 11 while heating them, the circuit board 13 and the liquid crystal display body 11 are adhered to each other, and the anisotropy existing between the connection terminals 12 and 14 is increased. The anisotropic conductive film formed by the conductive material 16 in the conductive adhesive 15 electrically connects the connection terminals 12 and 14.

[0003]

However, since the surface of the connection terminal 12 or 14 is smooth and flat, the conductive material 16 is pushed out from between the connection terminals 12 and 14 when pressure is applied. In addition, as shown in FIG.
Since 14 is often formed to have a slightly convex cross-sectional shape due to the erosion when it is formed by etching, the conductive material 16 is more likely to flow out at this time. Will increase. Therefore, the amount of the conductive material 16 that conductively connects the connection terminals 12 and 14 is reduced, and the connection reliability is reduced. Therefore, the connection width of the conventional connecting terminal is required to be predicted in advance that the conductive material 16 will flow out, and to secure a required width that allows the conductive material 16 to remain at a minimum between the terminals. It was an obstacle to the fine pitch reduction. In view of the above circumstances, the present invention provides an anisotropic conductive film connection terminal that prevents the conductive material from flowing out and improves the connection reliability even when the connection terminal width is small and enables a fine pitch. To aim.

[0004]

In order to achieve the above-mentioned object, the means adopted by the present invention is to apply pressure and heat between connecting terminals arranged facing each other with an anisotropic conductive adhesive interposed therebetween. In the anisotropic conductive film connection terminal in which the connection terminals are conductively connected by an anisotropic conductive film, the surface of at least one of the connection terminals arranged facing each other is roughened. Is an anisotropic conductive film connection terminal.

[0005]

According to the present invention, by roughening at least one surface of the facing connection terminals, when pressure is applied between the connection terminals, it is anisotropic due to the resistance due to the unevenness of the roughened surface. The flow of the conductive material contained in the conductive conductive adhesive from between the connection terminals is suppressed, and a required amount of the conductive material sandwiched between the connection terminals is secured, so that the connection reliability is improved. Therefore, the width of the connection terminal can be reduced, and the fine pitch can be improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. still,
The following examples are examples of embodying the present invention and do not limit the technical scope of the present invention. FIG. 1 is a schematic view showing a cross section of an embodiment in which a liquid crystal display body 3 and a circuit board 2 on which a printed wiring circuit is formed in a calculator are bonded to each other at a connecting terminal portion. The connection terminal 4 and the connection terminal 1 provided on the circuit board 2 are electrically connected by the conductive material 6 contained in the anisotropic conductive adhesive 5. Anisotropic conductive adhesive 5
Contains a conductive material 6 which is a conductive particle in the adhesive, and when the circuit board 2 and the liquid crystal display body 3 are pressed in the bonding direction at the time of bonding work, between the connection terminals 1 and 4. A conductive film is formed by the conductive material 6 that is sandwiched by, and the connection terminals 1 and 4 are conductively connected. At this time, the conductive material 6 in the anisotropic conductive adhesive 5 which is not interposed between the connection terminals 1 and 4 does not participate in the conductivity. The liquid crystal display body 3 has a liquid crystal display portion formed on a thin glass substrate, and a plurality of connection terminals 4 for connecting to the circuit board 2 are provided at one end in a row. A plurality of connection terminals 1 are also arranged in a row at one end of the circuit board 2 on which a circuit for operating the liquid crystal display 3 is formed. The connection between the connection terminals 1 and 4 is required to be thin, such as a calculator, because soldering and lead wire extraction are also restricted. The conductive connection and the bonding between the substrates are simultaneously made. The circuit board 2 and the liquid crystal display 3 are joined to each other by applying an anisotropic conductive adhesive 5 to the formation portions of the connection terminals 1 and 4 formed on each and then applying a predetermined heat and pressure. It At this time, among the conductive materials 6 contained in the anisotropic conductive adhesive material 5, the connection terminal 1
Conductive connection is established between the connection terminals 1 and 4 by the conductive material 6 interposed between the connection terminals 1 and 4.

In the conventional structure, the surfaces of the connection terminals 1 and 4 are smooth, and further, the thickness of the peripheral portion is reduced due to the erosion when formed by etching, and the connection terminals 1 and 4 are formed to have a slightly convex sectional shape. Since the conductive material 6 is sandwiched between the connection terminals 1 and 4 and receives pressure,
Is less likely to flow out of the connection terminals 1 and 4 and be sandwiched between them. Therefore, conventionally, the width of the connection terminals 1 and 4 was required to be large enough to leave the conductive material 6 sufficient to secure the conductivity reliability, but the surface of the connection terminals 1 and 4 according to the present embodiment is shown in FIG.
As shown in a partially enlarged view in Fig. 1, since the surface of the connection terminal 1 is roughened and fine irregularities are continuously formed,
The resistance due to the unevenness reduces the flow-out of the conductive material 6. Therefore, even if the width of the connection terminals 1 and 4 is smaller than the conventional one, the number of the conductive materials 6 sandwiched between the connection terminals 1 and 4 can be secured, the reliability of the conductive connection can be secured, and the connection can be made more easily than the conventional configuration. A fine pitch is possible in which a large number of connection terminals can be arranged within a fixed width by reducing the width of the terminal portion. By the way, the lower limit of the spacing between the connection terminals in the conventional configuration is 200 μm / pitch, but in this embodiment, it is 200 μm.
Fine pitch less than / pitch is possible. The roughening of the surfaces of the connection terminals 1 and 4 can be performed by processing such as sandblasting and reverse sputtering.

[0008]

As described above, according to the present invention, by roughening at least one surface of the connecting terminals facing each other, when pressure is applied between the connecting terminals, unevenness of the rough surface is caused. The resistance prevents the conductive material contained in the anisotropic conductive adhesive from flowing out between the connection terminals, and the conductive material sandwiched between the connection terminals is secured, so that the connection reliability of the connection terminals is improved, It is possible to provide an anisotropic conductive film connection terminal that can improve the fine pitch when forming the connection terminal.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an anisotropic conductive film connection terminal constituent portion according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the anisotropic conductive film connection terminal shown in FIG.

FIG. 3 is an enlarged cross-sectional view of a conventional anisotropic conductive film connection terminal (when the surface of the connection terminal is flat).

FIG. 4 is an enlarged cross-sectional view of a conventional anisotropic conductive film connection terminal (when the surface of the connection terminal is slightly convex).

[Explanation of symbols]

 1, 4 ... Connection terminal (anisotropic conductive film connection terminal) 5 ... Anisotropic conductive adhesive 6 ... Conductive material

Claims (1)

[Claims] 1. An anisotropic conductive material in which an anisotropic conductive film conductively connects between the connecting terminals by applying pressure and heat between the connecting terminals facing each other with an anisotropic conductive adhesive interposed. In the film connecting terminal, the surface of at least one of the connecting terminals arranged facing each other is roughened to form an anisotropic conductive film connecting terminal.