Anisotropic conductive film, method for producing the same, and joined structure using the same

Abstract

An anisotropic conductive film, containing a resin film; and conductive particles aligned into a monolayer within the resin film adjacent to or on one plane of the resin film with respect to a thickness direction of the resin film, wherein a distance between the one plane of the resin film and a center of the conductive particle is 9 μm or less based on 10-point average.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This is a continuation of Application No. PCT / JP2008 / 065686 filed on Sep. 1, 2008.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an anisotropic conductive film capable of electrically and mechanically connecting an electronic part (e.g. IC chip, and a liquid crystal display (LCD) panel in a liquid crystal display (LCD)) and a substrate, or connecting substrates, and also relates to a joined structure using the anisotropic conductive film.[0004]Moreover, the present invention also relates to a method for producing an isotropic conductive film (a film containing aligned particles) in which conductive particles aligned into a monolayer at a pitch of micron-order in a resin film.[0005]2. Description of the Related Art[0006]Anisotropic conductive films (ACF) have conventionally been used as means for connecting electronic parts and a circuit board, and the like. The anisotropic conductive film i...

AI Technical Summary

Benefits of technology

[0017]The present invention aims at solving the aforementioned problems in the art, and achieving the following objects. Namely, an object of the present invention is to provide an anisotropic conductive film which has excellent conduction reliability by suppressing the movement of conductive particles at the time of the connection between an electronic part or the like and a substrate, and securing the high capturing rate of the conductive particles, and to provide a joined structure of an electronic part or the like and a substrate, which has a high capturing rate of conductive particles and has excellent conduction reliability, formed by using the anisotropic conductive film.

[0018]Another object of the present invention is to provide a simple and efficient method for producing an anisotropic conductive film in which conductive particles aligned into a monolayer at a pitch of micro-order in a resin film.

[0023]In the anisotropic conductive film according to <1>, the conductive particles are aligned into a monolayer adjacent to or on one plane of the resin film with respect to the thickness direction thereof, and the center of the conductive particle is distant from 9 μm or less. Accordingly, when an electronic part or the like and a substrate are joined using the anisotropic conductive film, the conductive particles are not easily influenced by the flow of the resin, and are captured by a connection terminal at high ratio, providing excellent conduction reliability.<2> The anisotropic conductive film according to <1>, wherein a distance between a center of the conductive particle and a center of the adjacent conductive particle is 1 μm to 30 μm based on 10-point average.<3> The anisotropic conductive film according to any of <1> or <2>, wherein the anisotropic conductive film is obtained by simultaneously spraying the conductive particles, to which electrostatic potential is applied by an electrostatic potential applying unit, by means of one spraying unit, and resin particles by means of another spraying unit onto a processing surface so as to align the conductive particles into a monolayer within the resin film formed of the resin particles.

[0031]According to the present invention, there can be provided an anisotropic conductive film which has excellent conduction reliability by suppressing the movement of conductive particles at the time of the connection between an electronic part or the like and a substrate, and securing the high capturing rate of the conductive particles, as well as a joined structure of an electronic part or the like and a substrate, which has a high capturing rate of conductive particles and has excellent conduction reliability, formed by using the anisotropic conductive film.

[0032]According to the present invention, moreover, there can be provided a simple and efficient method for producing an anisotropic conductive film in which conductive particles aligned into a monolayer at a pitch of micro-order in a resin film.

Problems solved by technology

Since the conductive particles are dispersed in the insulating adhesive layer, the anisotropic conductive film has a problem such that the conductive particles are moved along with the movement of the insulating adhesive agent by heating and contact bonding at the time of the connection.

In this system, however, the charge of the conductive particles can be lost within only several tens seconds, it is difficult to maintain the aligned state of the conductive particles on the insulating adhesive layer.

In this method, however, the electric charge of the conductive particles are diffused as the thickness of the adhesive layer is increased, and thus the fine alignment of the particles corresponding to the electrode cannot be attained.

Therefore, it is difficult to align the conductive particles into a monolayer.

In this method, however, the currently commercially available conductive particles cannot be used, and there is a problem in versatility.

Accordingly, it is a current situation that a simple method, which can align conductive particles into a monolayer in an insulating resin film at a pitch of micro order without causing the aggregation of the conductive particles, and align the conductive particles on one plane of the insulating resin film in the thickness direction thereof, has not been yet provided.

Images