JPS6251116A - Manufacture of anisotropically conducting film - 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 method of manufacturing an anisotropic conductive film used for connecting printed circuits together.

(Prior Art) A method of using an anisotropic conductive film is known as one of the methods for interconnecting electronic circuit members such as printed circuits, flexible printed circuits, and flexible printed cables (for example, Electronic Technology No. 26S No. 7). No. 119-120).

In this method, first, as shown in FIG. Insulating base material 14
A second electronic circuit member 1 on which a large number of electrodes 15 are formed
6, an anisotropic conductive film 17 is sandwiched between the connection points of the two, and the anisotropic conductive film 17 is formed into a film by dispersing metal particles 19 in a hot melt adhesive 18. Then, as mentioned above, the two-type circuit member 13.1
When the adhesive 18 is sandwiched between the electrodes 12 and 15 and heated and pressurized, the adhesive 18 protrudes between the electrodes 12 and 15 facing each other as shown in FIGS. It can be taken. Since the metal particles 19 remain wrapped in the adhesive 18 at other locations, insulation is maintained. In this way, the anisotropic conductive film 17 exhibits anisotropy in that conduction can be established in the thickness direction but not in the width direction, that is, it maintains insulation properties.

Therefore, it is suitable for connecting electronic circuit members with extremely small distances between electrodes.

However, in the anisotropic conductive film 17 described above, if the density of the metal particles 19 contained is low, the conduction resistance is too large, and conversely, if the density of the metal particles 19 is increased in an attempt to lower the conduction resistance, the insulation There is the contradictory problem of decreased performance, and so far no good product has been obtained that can solve this problem.

[Object of the Invention] In view of the above-mentioned problems, an object of the present invention is to provide a method for manufacturing an anisotropic conductive film with low conduction resistance in the conductive part and high insulation in the insulating part, that is, with excellent reliability. It's about doing.

[Structure of the invention]

In order to achieve the above object, the method of the present invention provides kjAl! placed on a patterned electrode. A conductive polymer is grown and diffused in the thickness direction of the hot-melt adhesive thin film by electrolytic polymerization to form an anisotropic adhesive film corresponding to the pattern of the patterned electrode on the hot-melt adhesive thin film. It is characterized by being provided with a conductive pattern.

[Embodiments of the invention]

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

FIG. 1(a) shows an embodiment of the patterned electrode 1 used in the present invention, where the reference numeral 2 is an electrode, in this case a copper plate with a diameter of several micrometers to several tens of micrometers mounted on a base such as a copper plate. The cylindrical electrodes 2 are welded so as to be spaced apart from each other and are covered with an insulating film 3 so that only the end faces of each are exposed.

In addition, as another example, as shown in this figure (b),
Similarly to the above, electrodes 2 made of a copper plate several microns thick are welded to a copper plate parallel to each other and separated from each other, and an insulating film 3 is covered with only the end face of each electrode exposed.

As shown in FIG. 2, an insulating hot-melt adhesive thin film 4 is placed on the patterned electrode 1 thus formed, and this is placed facing a counter electrode, for example, a normal flat electrode 5, to form an electrolytic container 6. Place inside. The electrolytic solution in the electrolytic container 6 contains a conductive polymer such as pyrrole, thiophine, or aniline as an electrolyte. As the hot-melt adhesive thin film 4, an insulating film made of metal salt ionomer, EAA, EVA, EEA, etc., which has good adhesion to printed circuit boards, flexible printed cables, etc., is used.

In this way, electricity is applied between both electrodes 155 in the electrolytic container 6, and the conductive polymer is diffused in the hot melt adhesive thin film 4 by electrolytic polymerization, thereby forming a conductive material corresponding to the pattern electrode of the pattern electrode l. Grow the pattern through its thickness. This growth state is shown in FIGS. 3(a), (b), and (c).

By the above method, the anisotropic conductive film 7 shown in FIGS. 4(a) and 4(b) is obtained. Here, reference numeral 8 is a conductive part, and reference numeral 9 is an insulating part, and this figure (a) is obtained corresponding to the pattern electrode l of Fig. 1 (a), and this figure (b) is the part obtained corresponding to the pattern electrode l of Fig. 1 (a). Figure 1 (b)
This was obtained in response to These Figure 4 (a),
It goes without saying that the anisotropic conductive film 7 shown in (b), as well as the respective conductive portions 8, are insulated from each other, and conduction is established in the thickness direction of the film, but not in the width direction.

The adhesive anisotropic conductive film 7 thus obtained is used to form a large number of electrodes 12 (usually copper foil) on the insulating base material 11 at the connection points, as shown in FIG. 5(a). Similarly, a large number of electrodes 1 are placed on the insulating base material 14.
5 is sandwiched between the connection points with the second electronic circuit member 16 on which the electrodes 12 and 15 are formed, and when heated and pressurized, conduction is broken between the opposing electrodes 12 and 15 as shown in FIGS. 5(b) and 5(c). , and insulation is maintained between adjacent electrodes. Moreover, since the base material of this anisotropic conductive film 7 is a hot melt adhesive resin, both electronic members 13 and 16 can be easily and firmly bonded together by the aforementioned heating and pressing.

〔Effect of the invention〕

As described above, according to the present invention, an anisotropic conductive film can be formed with the conductive part and the insulating part clearly separated, so that the conduction resistance of the conductive part can be further reduced, and the insulation of the insulating part An anisotropic conductive film with higher properties, that is, excellent reliability, can be obtained. Moreover, since it is possible to obtain a material corresponding to a patterned electrode, there is also the effect that an anisotropic conductive film having a pattern as required can be obtained.

[Brief explanation of the drawing]

1(a) and 1(b) are partially cutaway perspective views showing one embodiment and other embodiments of the patterned electrode according to the present invention, the second is a schematic diagram showing the state of electrolytic polymerization, and FIG. is a vertical cross-sectional view showing the state of growth of a conductive pattern by electrolytic polymerization;
A) and (B) are perspective views of the anisotropic conductive film obtained in accordance with FIGS. 1A and 1B, and FIG. 5 is a perspective view of the anisotropic conductive film obtained according to the present invention. FIG. 6 is a sectional view showing a conventional anisotropic conductive film in use. 1 - Patterned electrode 2 - Electrode 3 - Insulating film 4 - Hot melt adhesive thin film 5 - Planar electrode 6 - Electrolytic vessel 7 - Anisotropic conductive film 8 - Conductive part 9 - Insulating part Fig. 1 (a) (b) Figure 2
Figure 3 Figure 4 Figure 5 (A') (0)
(c) A-A fitting Figure 6

Claims (3)

[Claims] (1) A conductive polymer is grown and diffused by electrolytic polymerization in the thickness direction of an insulating hot-melt adhesive thin film placed on the patterned electrode to form the pattern of the patterned electrode on the hot-melt adhesive thin film. 1. A method for producing an anisotropic conductive film, which comprises imparting an anisotropic conductive pattern corresponding to the above. (2) A patent characterized in that the anisotropic conductive pattern is such that each conductive part is scattered apart from the adjacent conductive part in the cross section in the thickness direction of the anisotropic conductive film. A method for manufacturing an anisotropic conductive film according to claim 1. (3) The anisotropic conductive pattern is characterized in that each conductive part is separated from the adjacent conductive part and is in the form of parallel lines. A method for producing an anisotropic conductive film.