JPS6348150B2 - - Google Patents

Description

Detailed Description of the Invention For example, in a liquid crystal display device or a display device using a light emitting diode, in order to connect each terminal of the display element, for example a light emitting diode, to another part such as a display drive circuit part, for example, the display part is A first wiring section is provided on one side edge of the provided first substrate in which wiring lines extending to become terminal leads of the display element are arranged in parallel, and on the other second substrate having the circuit section,
Similarly, extending to one side edge of the first wiring section is provided corresponding to each wiring, that is, each terminal lead, and each wiring to be electrically connected to these is arranged in parallel. providing a second wiring section,
Corresponding wirings of these first and second wiring parts are electrically connected to each other.

Normally, as described above, as a means for electrically connecting the first and second wiring parts each having a plurality of wirings arranged insulated and separated from each other on the first and second substrates, for example, There is a so-called zebra-type connector that fits into the side edge of the above-mentioned board where the wiring part is provided and has contacts that come into contact with each wiring part. There are disadvantages such as non-uniformity in the contact pressure between the contacts, limitations on the spacing between the contacts, which limits the wiring pattern, and high contrast.

Another method is to print and apply a conductive adhesive in which conductive powder is mixed onto the wires of one wiring section that are to be connected to each other, for example.
Corresponding wirings of the other wiring section may be overlapped and connected by thermocompression bonding via this adhesive. In this case, the conductive powder of the conductive adhesive is in the form of particles, and the amount of the conductive powder mixed with the adhesive is 70% in terms of solid ratio.
% or more, and unless printing is performed two or more times, a sufficient amount of adhesive for adhesion cannot be obtained, resulting in poor workability. For this reason, a problem arises in that when the amount of conductive material mixed in is reduced, the electrical resistance increases.

Furthermore, as another electrical connection means, for example, a conductive material in which particulate conductive materials are similarly dispersed in a hot-melt adhesive so that these particulate conductive materials do not come into contact with each other and are arranged in a single layer can be used. An adhesive sheet body is formed, and this sheet body is stacked on top of each other so that the first and second wiring portions described above are opposed to each other, and is then passed through the plurality of wires arranged in parallel in each wiring portion. There is a method in which the corresponding wires are electrically connected to each other by the particulate conductive material by sandwiching the wires together and applying heat and pressure. However, in this case, when the conductive adhesive sheet is inserted between the wiring parts and heated and pressurized, the pressure is mainly applied only to the particulate conductive material, and sufficient adhesion force cannot be obtained, and the particulate conductive material and 1st
Since each wiring of the second wiring part is connected by point contact, there is a drawback that the electrical resistance between both wiring parts becomes large.

In addition, as another electrical connection means, on each wiring of the first or second wiring part, particulate conductive material is similarly mixed with a thermosetting adhesive in an amount that does not touch each other and printed. Alternatively, there is a method in which the first and second wiring portions are coated and cured by heating and pressure so that the corresponding wirings face each other, but in this case, for example, a curing time of 5 minutes or more is required, which significantly reduces productivity. Not only does this result in a low cost, but it also has the drawback that, as in the case of the sheet body described above, the particulate conductive material is in point contact with the wiring surface, so that the electrical resistance between the two becomes large.

The present invention eliminates the above-mentioned drawbacks, and makes it possible to reliably and successfully electrically connect both wiring portions at high productivity and at low cost without causing an increase in electrical resistance at the electrical connection portions. The present invention provides an electrical connection sheet that can be used.

An example of an electrical connection sheet according to the present invention will be explained with reference to FIG. 1 in the figure shows the connecting sheet according to the present invention as a whole.

In the present invention, a fibrous conductor 3 is mixed into an insulating adhesive 2, and the fibrous conductor 3 is oriented substantially along one direction, and the conductors 3 are almost in contact with each other. A conductive layer 4 is insulated and dispersed by an adhesive 2 to prevent
A sheet-like body is constructed by. This sheet-like conductive layer 4 can be formed by coating on a support sheet or a release sheet 5 as required.
Here, it is desired that the fibrous conductor 3 is mixed in an amount of 5 to 20 parts by volume per 100 parts by volume of the adhesive 2, and the thickness of the sheet-like conductive layer 4 is determined by the amount of electricity between the wirings, which will be described later. In the unused state before physical connection
It is desirable to select a thickness of 20 to 120 μm.
As the fibrous conductor, a conductor having a diameter of 5 to 50 μm and a length of 0.05 to 3 mm, such as fibrous carbon, is used. The reason why it is desirable to select 5 to 20 parts by volume of the fibrous conductor 3 for 100 parts by volume of the adhesive 2 is that less than 5 parts by volume lowers the conductivity, and 20 parts by volume is less than 5 parts by volume. If the thickness exceeds 20 μm, the orientation becomes difficult, so it is desirable to select the thickness of the sheet-like conductive layer 4 between 20 and 120 μm.
This is because when the thickness exceeds 120 μm, the level of electrical resistance increases.

FIGS. 2 and 3 show an example of a case where a pair of objects to be joined, that is, a pair of wires are electrically connected to each other by the connection sheet 1 according to the present invention.
In the figure, 6 is a first substrate, and this substrate 6 is
A first layer is made of a transparent substrate, such as a glass substrate, constituting the display device, and on which a plurality of wires 7a, for example terminal leads, made of a transparent conductive layer such as indium oxide with a thickness of 200 Å are arranged. A wiring portion 7 is attached thereto. Also, 8 is the second
This substrate is made of, for example, a polyethylene terephthalate substrate, and is made of, for example, a 35 μm thick copper substrate.
Each wiring part 7a of the first wiring part 7 is made of Cu foil.
A second wiring part 9 in which a plurality of wirings 9a corresponding to the wirings 9a are arranged is attached. These, the first and second
The wirings 7a and 9a of the wiring portions 7 and 9 are connected to one side edges 6a and 8 of the first and second substrates 6 and 8, respectively.
Extending to a, the husband and husband are insulated and arranged side by side. Also, the wirings 7a and 9 to be connected to each other
Corresponding wirings of a are connected to both substrates 6 and 8.
are arranged in a plane, and with their side edges 6a and 8a abutting each other, so that at least their ends extend along a straight line substantially parallel to one direction X-X', facing each other. Place it in In this state, the connecting sheet 1 according to the present invention explained in FIG.
The conductive layer 4 is placed over the first and second wiring portions 7 and 9 so as to extend over the conductive layers 7 and 8a, and is heated and pressurized to bring them into contact with each other. In this case, in the conductive layer 4, the orientation direction of the conductor 3 explained in FIG.
Each wiring 7a, 9 of the first and second wiring parts 7 and 9
It is arranged along the extending direction X-X' of the end portion of a. In this way, the fibrous conductor 3 of the conductive layer 4 is pressed across the ends of the corresponding wirings 7a and 9a arranged in a straight line along the X-X' direction. Therefore, the corresponding wirings 7a and 9a are electrically connected to each other by the fibrous conductor 3. Here, the fibrous conductors 3 are electrically insulated from each other by the adhesive 2, so that between the adjacent wirings 7a, 9a
If the distance between the conductors 3 is selected to be sufficiently larger than the diameter of the conductors 3, the adjacent wirings 7a can be separated by the conductors 3.
9a can be prevented from being electrically connected to each other. Mechanically, they are connected by a sheet-like conductive layer 4 supported by an adhesive 2 and bonded by the adhesive 2. Furthermore, this mechanical connection is made more reliable if the seat 1 is provided with a support seat 5.

Note that here, since the sheet 1 has flexibility,
Both substrates 6 and 8 are not limited to being arranged two-dimensionally, but can also be arranged at a desired angle, for example, at right angles, as shown in FIG.

In some cases, as shown in FIG. 5, the first and second substrates 6 and 8 as a pair of objects to be bonded are arranged such that the ends of the wirings 7a and 9a to be connected to each other face each other. By overlapping them and interposing the connection sheet 1 between them, the corresponding wirings 7a and 9a can be electrically connected. In this case, the connecting sheet 1 is a sheet with only the adhesive conductive layer 4, or a sheet with the adhesive conductive layer 4 applied on the release sheet 5, and the release sheet 5 is peeled off before use. As shown in FIG.
Each wiring 7a is placed between the overlapping portions of the wirings 7a and 9a to be connected to each other on the substrates 6 and 8.
Therefore, it is common to 9a and is sandwiched across. In this case as well, the fibrous conductors are arranged so that the direction in which they are oriented is along the direction in which the ends of each of the wirings 7a and 9a extend. In this state, the overlapping portions of the substrates 6 and 8 are pressed and heated as shown by arrows a and b. In this way, as shown in FIG. 7, between the wires 7a and 9a which are overlapped with each other, the adhesive conductive layer 4 is crushed by being pressurized from both sides in the thickness direction. In the thickness direction, only the fibrous conductor 3 is mainly held between the wires 7a and 9a which are stacked on top of each other, and the conductors 3 are in close contact with each other along the opposing surfaces of the wires 7a and 9a. Furthermore, the adhesive 2 interposed between the wires 7a and 9a superimposed on each other due to the pressure in the thickness direction is removed from the wires 7a and 9a with respect to the portion that has entered between the adjacent conductors 3.
The remaining adhesive 2 between the wires 7
a and 9a are extruded to a portion where they are not overlapped, and the space between both substrates 6 and 8 is filled in this portion. In this way, between the wirings 7a and 9a superimposed on each other, the conductor 3 is formed in a single layer or in multiple layers in the thickness direction of the layer 4.
a and exhibits good electrical conductivity, but due to the presence of the adhesive 2, a large electrical resistance is exhibited in the plane direction, particularly between adjacent wirings 7a and 9a. The corresponding wirings 7a and 9a overlapped with each other in this way are electrically connected to each other by the conductor 3, and mechanically, the parts other than the overlapping parts of the wirings 7a and 9a are mainly filled. They are firmly connected by a sufficient amount of adhesive 2. As described above, since the conductors 3 are insulated from each other by the adhesive 2, the adjacent wires 7a
When selecting the distance between the wires 9a to be sufficiently larger than the diameter of the conductor 3, the distance between the adjacent wires 7a, 9a
It is possible to avoid short-circuiting between the two by the conductor 3.

Further, embodiments of the present invention will be described.

Example 1 Copolymer of acrylonitrile and butadiene (trade name: Hiker 1001, manufactured by BF Gutdrich Co., Ltd.) Phenol resin (trade name, BKR2620, manufactured by Showa Union Gosei Co., Ltd.) Solvent: Methyl ethyl ketone carbon fiber (diameter 7 μm, length 300 μm, specific gravity 1.74) (manufactured by Toray Industries, Inc.) ... 60 parts ... 40 parts ... 400 parts ... 30 parts of the paint is applied onto a release sheet, and the fibrous conductor,
In other words, the carbon fibers are oriented in almost one direction, and the thickness of the coating after drying is
A sheet 1 was obtained by forming an adhesive conductive layer 4 to a thickness of 40 μm. The release sheet of this sheet 1 is peeled off, the corresponding wirings of the first and second substrates are stacked facing each other, and the adhesive conductive layer 4 is sandwiched between them.
As explained in Figures 5 to 7 at ℃, 3
A pressure of Kg/cm ² for 10 seconds was applied to connect the corresponding wirings of both substrates and their characteristics were measured. In this case, the wiring on each of the first and second substrates is made of a copper foil pattern with a width of 1 mm and a pitch of 2 mm. That is, they were bonded by sandwiching the adhesive conductive layer 4 and stacking them facing each other. In this case, the conductive resistance between the first and second wires facing each other and connected by the conductive layer 4 is 20Ω or less, and the insulation resistance between adjacent wires that should be insulated from each other is 1×10 ¹⁰ It became more than Ω. In addition, the peeling force of both substrates in this case is 4
Kg/cm. After forced aging at 45°C and 95% humidity for one week, the changes in characteristics were as follows:
The insulation resistance was 30Ω or less, and the insulation resistance was 1×10 ⁹ Ω or more.

Example 2 Butadiene-styrene copolymer (trade name, Solprene 411, manufactured by Asahi Kasei Corporation) Terpene phenol resin (trade name, YS Polysta, manufactured by Yasushi Oil Co., Ltd.) Anti-aging agent toluene carbon fiber…60 parts…40 parts…0.5 parts …200 parts…25 parts of the paint is applied to the fibrous conductor on the release sheet.
In other words, the carbon fibers are oriented in almost one direction, and the thickness of the coating after drying is
An adhesive conductive layer 4 was formed to have a thickness of 50 μm to obtain a sheet 1. Using this sheet 1, the release sheet was peeled off to connect the wirings of the first and second substrates in the same manner as in Example 1. This connection process was carried out at 110° C. and under pressure of 3 kg/cm ² for 10 seconds. The peeling force in this case was 2 kg/cm. When the electrical characteristics were measured in the same manner as in Example 1, the conduction resistance was 30Ω or less, and the insulation resistance was 1×
After the same forced aging treatment, the conduction resistance was ⁴⁰ Ω or less, and the insulation resistance was 1×10 ¹⁰ Ω or more.

Example 3 Butadiene-styrene copolymer (trade name manufactured by Ciel Chemical Co., Ltd., Califrex TR1107) Aliphatic petroleum resin (trade name manufactured by Arakawa Chemical Co., Ltd., Alcon P115) Toluene carbon fiber...50 parts...50 parts...200 parts...25 A coating composition having the composition of 2 is applied onto a polyester film with the fibrous conductor, that is, the carbon fibers are oriented almost in one direction, and an adhesive conductive layer is applied so that the thickness of the coating film after drying is 50 μm. 4 was formed to obtain sheet 1. Using this sheet 1,
The polyester film was peeled off to connect the wirings of the first and second substrates in the same manner as in Example 1.
This connection process was carried out at 20° C. and under pressure of 3 kg/cm ² for 10 seconds. In this case, the peeling force is 1
Kg/cm. When the electrical characteristics were measured in the same manner as in Example 1, the conduction resistance was 40 Ω or less and the insulation resistance was 1×10 ¹⁰ Ω or more. Similarly, after forced aging treatment, the conduction resistance was 50 Ω or less and the insulation resistance was 1×10 10 Ω or more. was more than 1×10 ⁹ Ω.

Example 4 Using the sheet 1 obtained in Example 2, first and second substrates having first and second wirings similar to those described in Example 1 were prepared as shown in FIGS. 2 and 3. As explained in 2.2.1, the wiring was laid out in a two-dimensional manner and connections were made between the wires. In this case, the conduction resistance was 40Ω or less and the insulation resistance was 1×10 ¹⁰ Ω or more, and after the same forced aging treatment, the conduction resistance was 50Ω or less and the insulation resistance was 1×10 ⁹ Ω or more.

An example of the oriented coating means for the fibrous conductor for obtaining the sheet 1 according to the present invention will be explained with reference to FIG. In this example, a tank 10 is filled with an adhesive paint 11 containing a fibrous conductor, and a roll 12 immersed in the paint 11 is rotated. On the other hand, a rotating roll 13 partially immersed in the paint 11
A rolling contact roll 14 is provided which rolls into contact with this. Further, a supply roll 5 for supplying a release sheet or a support sheet 5 is provided, and this sheet 5 is wrapped around a rotating roll 16 so that the roll 16 and the rolling roll 1 are in contact with each other.
4, and by rotating the sheet 5, the sheet 5 is fed out from the supply roll 15 and guided to the drying oven 17. In this configuration, the rolls 12, 13, 16 are respectively
They are rotated in the directions indicated by d and e, respectively. According to such means, the paint 11 in the tank 10 is forcibly moved in a circular direction in one direction according to the rotation of the roll 12, and a laminar flow is generated in the tank 10. As a result of the laminar flow, the fibrous conductors are aligned along the laminar flow direction. Therefore, if the roll 13 is rotated in the direction along this laminar flow and the paint 11 is deposited on its circumferential surface, the fibrous conductor is oriented and deposited in the direction along the rotation, and this is applied to the rolling contact roll 14. Sheet 5 transferred and transferred to this
The adhesive conductive coating applied onto the sheet 5 is applied with the fibrous conductors oriented in one direction, ie along the direction of movement of the sheet 5. 8 is a squeegee and applies paint 1 to roll 13.
The coating amount of No. 1 and the thickness of the coating film on the sheet 5 are controlled. In this way, the electrical connection sheet 1 according to the present invention is obtained, in which the conductive layer 4 in which the fibrous conductors are oriented in one direction is deposited on the sheet 5.

As described above, in the connecting sheet 1 according to the present invention, the fibrous conductor 3 is oriented in one direction in the adhesive 2, so when connecting the first and second wiring, it is necessary to adjust the orientation. By matching the extension directions of the wiring at the connecting portion, the wiring and the conductor 3 can be brought into good line contact, so that the connection between the two wirings can be made with low resistance. In addition, since it is easy to manufacture and handle, the connecting part can be constructed at low cost.
The benefits of putting it into practical use are great.

[Brief explanation of drawings]

FIG. 1 is an enlarged perspective view showing a cross section of a part of a main part of an example of a connecting sheet according to the present invention, and FIGS.
The figures are an enlarged plan view of the main parts, a sectional view taken along the line A-A, and FIGS. 4 and 5.
The figure is an enlarged sectional view of the main part showing another connection mode using the connection sheet according to the present invention, FIGS. 6 and 7 are explanatory views thereof, and FIG. 8 is a configuration diagram of an example of means for orienting fibrous conductors. be. 1 is an electrical connection sheet according to the present invention, 4 is a sheet-like conductive layer, 2 is its adhesive, 3 is a fibrous conductor, 5 is a support sheet or a release sheet, 6 is a first
7 is a first wiring section made up of a plurality of wirings 7a, and 9 is a second wiring section made up of a plurality of wirings 9a.

Claims (1)

[Claims] 1 An adhesive electrical connection sheet in which fibrous conductors are dispersed in an insulating adhesive in a mutually insulated state, wherein the fibrous conductors are arranged in one direction in a plane parallel to the main surface of the connection sheet. By using at least one main surface of the sheet as a bonding surface with the pair of objects to be joined, the fibrous conductor is brought into line contact with the pair of objects to be joined. An adhesive electrical connection sheet having conductivity in one direction and insulation in a direction intersecting the above-mentioned one direction.