JPS61195569A - Film connector and manufacture thereof - 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 Field of Industrial Application The present invention is useful for solving problems such as electrical connection between a liquid crystal display panel and a drive module, or electrical connection by soldering such as electrical components having high density terminal leads. The present invention relates to a film connector that can connect various parts, and a method for manufacturing the same.

BACKGROUND OF THE INVENTION In recent years, electric circuit components have become more densely packaged, patterns have become finer, and two components have become more compact.

As for display devices, the development of liquid crystal display devices has been remarkable, and various methods of electrical connection with peripheral modules have been studied accordingly.

Heretofore, several methods have been known for electrically connecting the corresponding electrodes of a plurality of circuit boards, and these will be described below.

First, one method is to form corresponding electrodes in the same shape and make them face each other, and then press the elastic connector between them to obtain an electrical connection.

A second method is to connect an insulating film with thermoplastic conductive ink and insulating ink alternately printed in stripes. Next, a third method is to obtain electrical connection using an anisotropic conductive adhesive containing powder or fibrous conductive filler.

Problems to be Solved by the Invention In such conventional methods, in the case of the first method, □ uniform pressure is always required, and alignment is difficult in fine-pitch electrodes, and the position may be distorted due to distortion. It has the disadvantage of causing misalignment. The second method has the disadvantage that it is difficult to produce narrow pitch patterns because there are many printing steps and there is a limit to fine pattern printing. The third method has the disadvantage that a flexible printed circuit board must be used to pull out the leads.

There is also a method of using metal conductive powder such as silver paste, but this method causes short circuits due to migration and has problems with reliability.

The purpose of the present invention is to eliminate such problems, and to provide a film connector and its manufacturing method that can ensure electrical connection even between high-density terminal leads and improve reliability. That is.

Means for Solving the Problem In order to solve this problem, the present invention uses copper on one main surface of a flexible insulating film.

a first metal film made of one of silver, nickel, and aluminum or an alloy thereof; and nickel.

A second metal film made of one of chromium, tungsten, and silver or an alloy thereof; a third isotropic conductive film made of carbon powder A-7 and synthetic resin; and a third isotropic conductive film made of carbon powder and synthetic resin. The film connector has a structure in which the third conductive film is also provided with a fourth anisotropic conductive film containing less carbon powder and having a larger particle size. Further, a first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof, and a first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof, and nickel, chromium, tungsten, silver, etc. A step of sequentially forming a second metal film made of one of these or an alloy thereof, and forming a third isotropic conductive film made of carbon powder and synthetic resin into an arbitrary pattern by printing. Step 1 above. a step of etching away the second metal film, and forming a fourth anisotropic conductive film containing less carbon powder and having a larger particle size than the third conductive film, which is made of carbon powder and synthetic resin; This is the first method of manufacturing a film connector, which includes the step of forming a pattern on the entire surface.

Here, the first metal film has a metal 2 which can be a good conductor.
For example, although copper shows good results, nickel and nickel are also disadvantageous compared to copper in terms of electrical conductivity, but their use is advantageous in terms of oxidation resistance. For this first metal film, silver and aluminum can also be used, and alloys thereof including the above-mentioned copper and nickel can also be used. If a copper-nickel alloy is used, it has the same oxidation resistance as nickel. Favorable results can be obtained in this respect. Also, the second
The main purpose of the metal film is to prevent oxidation to protect the highly conductive first metal film. Further, the third isotropic conductive film can be used as an etching resist, and is formed as an auxiliary conductive film for the purpose of forming an arbitrary pattern and for increasing the connection accuracy as a connector. This third
The conductive film protects the underlying metal film as described above, and ensures conductivity when a crack occurs in the metal film, so an isotropic conductive film is required. Further, the fourth anisotropic conductive film needs to have adhesion to the object to be adhered, conduction in the thickness direction, and insulation in the lateral direction. Therefore, it is necessary to use less carbon powder than that of the third conductive film. Further, it is effective to make the particle diameter 7 .\ of the carbon powder larger than that of the carbon powder used for the third conductive film in terms of conduction in the thickness direction. This is because when compression is applied, if it is small, it will flow along with the flow of the synthetic resin, and it will not contribute to conductivity.

Function With this configuration, the film connector of the present invention can be broadly divided into two parts: a patterned film and an anisotropic conductive adhesive, and their functions ensure electrical connection even between high-density terminal leads. As a result, a film connector with improved reliability can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

First, FIG. 2 shows a cross section of a film in which two layers of metal films are formed to form the basis of a pattern. In Figure 2, 1 is a flexible insulating film, and here 3
8 μm polyethylene terephthalate (PET) film was used, but polyether sulfone (PE) film was also used.
S), polyimide (PI), and other films can also be used. On one main surface of this insulating film 1, copper was applied as a first metal film 2 having conductivity, and nickel was applied as a second metal film 3 which also served as oxidation prevention.
They were sequentially formed by sputtering to a thickness of 350 mm. These first. The second metal films 2 and 3 can be formed by other means than sputtering, such as EB (electron=g-line illumination) and plating. Next, on the second metal film 3, a thermosetting resin based on phenol resin (100 parts by weight), 60 parts by weight of carbon powder carbon black (acetylene black) as a conductive filler, and an average particle size of 0 ．．
06μm and 40 parts by weight of graphite (made by Nippon Graphite@),
A conductive paste (manufactured by Three Bond Co., Ltd.) using parts by weight of GSP4o and an average particle diameter of 5 μm was silk screen printed into an arbitrary pattern, and heat-cured at 130° C. for 30 minutes. The cross section is shown in FIG. 3, and 4 is a third isotropic conductive film made of conductive paste. This isotropic conductive film 4
The coating film 9 ＼ - The thickness is about 10 μm, and its cross section forms a semicylindrical shape as shown in the figure. Next, the underlying metal films 2 and 3 were etched using the isotropic conductive film 4 as a resist to obtain a pattern as shown in FIG. On the other hand, as shown in FIG. 6, the thermoplastic resin 6 is polyester [Toyobo Co., Ltd.
Anisotropic conductive adhesive 7 containing carbon powder 6 as a conductive filler.
[manufactured by ThreeBond Co., Ltd.] was attached to release paper 8 and prepared. Here, the carbon powder 7 is obtained by firing and solidifying 100 parts by weight of phenol resin [J-1000, manufactured by Matsushita Electric Works Co., Ltd.] and 100 parts by weight of acetylene black [manufactured by Denki Kagaku Co., Ltd.], and then pulverizing the powder ( Average particle size 2oμm
) was used in an amount of 5 parts by weight. Then, as shown in Fig. 1, the anisotropic conductive adhesive was applied to the pattern surface using a laminator at a roll temperature of 80°C and a film speed of 2 m/m.
The film was laminated to a thickness of 30 μm using an in-line method to create a film connector 9. In FIG. 1, 7a is a fourth anisotropic conductive film made of the anisotropic conductive adhesive 7 formed by this laminate.

As a connection test for this film connector, the line width was 325 μm, and the line width was 200 μm at equal intervals with a total pitch of 650 μm.
A 1.6 mm thick glass epoxy base substrate with 36 μm copper foil lined with book lines, and a 1.1 mm thick transparent conductive film (ITO) with a surface resistance of 10 Ω/hole were deposited on the same pitches as above. Prepare each etched glass plate and use a hot pressure bonding machine to attach it to the part to be fixed in advance on the film connector with a pattern formed at the same pitch.
℃.

After applying tackiness by pounding at 3okg/art, ○, 5sec, remove the release paper, align the electrodes on the glass epoxy board with the electrodes on one end of the film connector, and press lightly with your fingers to temporarily tighten. After fixing, heat it to 160℃ using a heat-pressing machine.
, 3 okg7cn5 , and the main crimping was performed for 30 seconds. This state is shown in FIG. 6, where 1o is a glass epoxy substrate and 11 is a metal electrode. Next, the electrode on the other end of the film connector is similarly given tackiness, and IT
After temporarily fixing it on the O glass plate, 160℃ and 9/c at 30℃.
The main crimping was performed for 11 hours and 45 seconds. This state is shown in FIG. 7, where 12 is a glass plate and 13 is an ITO electrode.

Further, FIG. 8 shows the metal electrode 1 on the polyimide film 14.
6 and a film connector 9 are shown connected.

In the connection between the film connector 9 and the object to be connected, whose states after the final crimping are shown in FIGS. 6 to 8, it was confirmed that the connection resistance did not change under various environments.

Effects of the Invention The film connector of the present invention is constructed as described above, and can be roughly divided into two types: a patterned film and an anisotropic conductive adhesive. In conventional flexible printed circuit boards, the surface of the copper foil pattern is flat, and when the anisotropic conductive adhesive is sandwiched and heat-pressed, the resin does not flow sufficiently.
However, in the film connector pattern of the present invention, the conductive paste constituting the third isotropic conductive film on the top layer is anisotropically formed during heat and pressure bonding. It pushes away the conductive adhesive and connects to the counter electrode, and the surface of the paste itself is porous.
The minute protrusions collapse and become surface connections. Further, the carbon filler in the anisotropic conductive adhesive is sandwiched between the paste and the electrode of the object to be connected, and is bitten into the paste side to some extent. This ensures that the initial connection is sufficiently maintained.

Then, as shown in Figures 6 to 8, when connecting to the object to be connected, the anisotropic conductive adhesive resin flows between adjacent electrodes, filling the gap and firmly fixing the film that has been distorted by pressure. do. Therefore, even during the environmental test period, the tensile force of the adhesive and the restoring force of the film constantly press down the connected electrodes to stabilize the contact resistance.

Further, the anisotropic conductive adhesive formed on the pattern provides both protection of the pattern and insulation of the surface. for example,
It has the effect of alleviating strong bending of the pattern, and even if the metal film rusts and partially lifts or cracks occur in the conductive paste, the coated anisotropic conductive adhesive layer protects the pattern body or insulation. It is effective in preventing pattern breakage by pressing strongly against the film. Furthermore, it also has the effect of protecting the metal pattern from moisture, which greatly contributes to reliability.

As described above, the film connector of the present invention has various characteristics and can be used for reliable electrical connections between liquid crystal display panels and drive modules, for which demand is rapidly increasing, and for electrical components with high-density terminal leads. It is something that can be connected, and its industrial nature is a dog.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the film connector according to the present invention, and FIG. 2 is a cross-sectional view showing a method of manufacturing the film connector according to the present invention. A cross-sectional view showing the state in which the second metal film is formed, FIG.
Figure 4 is a cross-sectional view showing a state in which a conductive paste is printed on the metal film shown in the figure, Figure 4 is a cross-sectional view showing a state in which a pattern is formed by etching the same as in Figure 3, and Figure 5 is also coated on release paper. A cross-sectional view showing the anisotropic conductive adhesive, No. 6
8 are sectional views showing the connection state of the film connector and the object to be connected after crimping according to the present invention. DESCRIPTION OF SYMBOLS 1... Insulating film, 2... First metal film, 3... Second metal film, 4...
Third isotropic conductive film, 6...Synthetic resin, 6...
...Carbon powder, 7...Anisotropic conductive adhesive, 7a...Fourth anisotropic conductive film, 9...
・Film connector. Name of agent: Patent attorney Toshio Nakao, 1 person [F
]C″1 Totsuka Gakudai − ′-1-ゎ憾 School 25

Claims (2)

[Claims] (1) A first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof, and a first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof, on one main surface of a flexible insulating film, and a first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof. a second metal film made of one of these or an alloy thereof; a third isotropic conductive film made of carbon powder and a synthetic resin; and a third conductive film made of carbon powder and a synthetic resin; and a fourth anisotropic conductive film containing less carbon powder and having a larger particle size than the film connector. (2) A first metal film made of one of copper, silver, nickel, and aluminum or an alloy thereof, and nickel, chromium, tungsten, and silver on the entire principal surface of the flexible insulating film. a step of sequentially forming a second metal film made of one of the following or an alloy thereof;
forming a third isotropic conductive film made of carbon powder and synthetic resin into an arbitrary pattern by printing;
, etching away the second metal film, and applying a fourth anisotropic conductive film made of carbon powder and synthetic resin and having less carbon powder and larger particle size than the third conductive film on the entire surface of the pattern. 1. A method for manufacturing a film connector, comprising the steps of forming a film connector.