JPH04121904A - Anisotropic conductive material and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an anisotropic conductive material having low conductive resistance and contact resistance, strength, stable resistant value even if stress is applied or it is rubbed and having little secular change by using a linear conductor as a conductor. CONSTITUTION:An anisotropic conductive material 1 is provided with an adhesive material layer 4, which is spread on an electrode for electrostatic planting and is removed after the curing of insulation material 3 which forms a structure body, metal short fibers 2, 2... which are electrostatically planted as multiple linear conductors into this adhesive material layer 4 and an insulation material 3, which is filled among the short fibers 2, 2... and cured so as to form the structure body, with short fibers 2, 2... oriented in thickness direction both ends of the short fibers 2, 2... exposed, from obverse and reverse side and the insulation material, for forming the abovementioned structure body, composed of different kinds of plural insulation materials 3a, 3b... and the structure body so composed as having plural layers. The short fibers 2, 2... are combined in plural number and then form an aggregate, and the short fibers 2, 2... are arranged on the surface of the insulation substrate 3 in checker board pattern.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a so-called anisotropic conductor that is conductive in the thickness direction but insulating in the plane direction, and a method for manufacturing the same. be.

[Conventional technology]

So-called anisotropic conductors, which are conductive in the thickness direction but insulating in the plane direction, have been widely used in fields such as electronic devices.

For example, due to its properties, anisotropic conductors are often used to connect printed circuit boards to each other, and to connect printed circuit boards to various electrical and electronic devices, especially liquid crystal display boards with fine connection pitches. .

Further, the anisotropic conductor can also be applied to printing electrodes of non-impact type printers.

In other words, in a non-impact type printer that records an image by transferring ink from an ink medium onto a recording medium using heat, thermal energy is applied to the ink medium in accordance with image information, and heat energy is applied to the ink medium in accordance with image information. Instead of using a recording head that carries a heat generating layer on the ink medium itself, electricity is applied only to the area corresponding to the image information through a printing electrode made of an anisotropic conductor to the heat generating layer of the ink medium. The image is recorded by causing the heating layer of the image forming apparatus to generate heat according to the image information.

Considering such an application example, the conductor of the anisotropic conductor is
Conduction resistance and contact resistance are low, and the conductor has strength,
It is desirable that the resistance value remains stable even when external force is applied or the material is rubbed. From this point of view, it is preferable to use a linear conductor made of metal fiber or the like as the conductor of the anisotropic conductor.

Conventionally, there are the following methods related to anisotropic conductors using this type of linear conductor and methods for manufacturing the same. That is, as shown in Japanese Patent Publication No. 58-58766, Japanese Patent Publication No. 60-32282, and Japanese Patent Publication No. 61-46922, a large number of magnetic linear conductors having approximately equal lengths have electrically insulating properties. The mixed liquid is held in the form of a sheet with a thickness approximately equal to the length of the magnetic linear conductor, and the mixed liquid is dispersed in a matrix liquid having a large number of regularly arranged convex portions. , and apply a nonuniform magnetic field in the thickness direction to the sheet-like mixed liquid to concentrate the magnetic linear conductors on the convex portions of the magnetic pole surface and orient them in the thickness direction. A device configured to solidify the matrix liquid while maintaining this state has been proposed and actually manufactured.

On the other hand, JP-A-59-93323 and JP-A-61-1
As shown in Publication No. 33586, metal wires or metal fibers are mixed with an insulating material and then injection molded into a disk-shaped mold from the center in the circumferential direction to form metal wires or metal fibers. There has also been proposed a structure in which a disk-shaped molded product is made in which the particles are oriented in the injection direction, and then this molded product is sliced along the circumferential direction to obtain a continuous sheet-like body.

[Problem to be solved by the invention]

However, the above conventional technology has the following problems. In other words, in the case of the former anisotropic conductor and its manufacturing method, metal fibers dispersed in a matrix liquid are oriented using a magnetic field, so it is difficult to increase the density of the conductor or arrange the conductors regularly. If this were to be done, it would be necessary to concentrate the magnetic field in one area or to generate the magnetic field regularly, which would require magnetic poles with complex shapes. Therefore,
There are problems in that the structure of a manufacturing apparatus for manufacturing an anisotropic conductor becomes complicated, resulting in high costs, and it is difficult to manufacture a large-sized anisotropic conductor.

Furthermore, since a magnetic field is applied to the matrix liquid before hardening to orient the metal fibers dispersed in the matrix liquid, the metal fibers must be able to move easily within the insulating material. Therefore, the matrix liquid is
Since the uncured viscosity is necessarily limited to low viscosity, the cured matrix becomes a flexible sheet-like material that can maintain a predetermined shape, such as the printing electrode of a printer. The problem is that it is difficult to create a structure.

On the other hand, in the case of the latter anisotropic conductor and its manufacturing method,
Since it is manufactured by injection molding an insulating material mixed with metal fibers into a mold, it is easy to make large sizes, or the metal fibers are oriented using the flow characteristics during injection molding. Therefore, there is a problem in that the conductors cannot be arranged regularly and not all the conductors necessarily penetrate through the insulating material and are electrically conductive. In addition, it is not only difficult to control the density of the conductor, but also
This requires a device or the like to cut the anisotropic conductor into thin pieces with high precision, which poses a problem in that the configuration of the manufacturing device becomes complicated.

Therefore, among the above problems, a method for solving the productivity problem and efficiently manufacturing an anisotropic conductor using metal fibers as a conductor is disclosed in Japanese Patent Application Laid-Open No. 63-34806. As mentioned above, methods applying the electrostatic flocking method have already been proposed.

This involves forming a flocking resin layer on a release sheet, flocking conductive short fibers onto the resin layer so that one end of the short fibers substantially reaches the release surface of the release sheet, and After curing the layer, the parts of the flocked short fibers that protrude from the resin layer are individually covered with an insulating resin coating, and the release sheet is peeled off.

However, this method requires the conductive fibers to penetrate the resin layer that serves as the hair flocking in order to obtain conductivity in the thickness direction. In addition to causing conductive fibers that do not penetrate to form, causing poor conductivity, there is also the problem that if the viscosity of the resin layer is low, the flocked conductive fibers will fall down before the resin layer hardens, resulting in conductivity in the plane direction. It has points. Also,
The problem is that it is not possible to prevent the conductive fibers from adhering to the resin layer by laying them down, and it is also impossible to remove the conductive fibers which have adhered to the resin layer by lying them down, so it is impossible to prevent conduction from occurring in the plane direction. It also has

Another problem is that the conductors cannot be arranged regularly.

Therefore, the present inventor solved the problems of the above-mentioned conventional technology,
By using a linear conductor as the conductor, the continuity resistance and contact resistance of the conductor are low, the conductor has strength, and the resistance value is stable even when external force is applied or rubbed. It is possible to manufacture anisotropic conductors with simple manufacturing equipment, which have little change in conductors over time, have no size restrictions, can arrange conductors in a high-density and regular manner, and can use a variety of insulators. We have already proposed an anisotropic conductor and its manufacturing method that can reduce costs (Japanese Patent Application No. 2-94975).

As shown in FIG. 21, this anisotropic conductor is coated on an electrode for electrostatic flocking, and an insulating material 10 forming a structure is used.
an adhesive layer lO1 that is removed after 0 is cured;
A large number of linear conductors 102, 102, etc. are electrostatically flocked to this adhesive layer 101, and the flocked linear conductors 102
．． The linear conductor 102 is filled and hardened between 102 and 102.
．． 102... are oriented in the thickness direction thereof, and both ends of the linear conductors 102, 102... are exposed from both the front and back sides. It is composed of

However, in the anisotropic conductor according to this proposal, since the insulating material 1.0 that forms the structure is made of one type of material, the structure that makes up the anisotropic conductor has a single layer structure. There is. Therefore, when heat resistance is required for the anisotropic conductor, for example, polyimide resin or the like having excellent heat resistance is used as the insulating material 100 for forming the structure.

However, when the anisotropic conductor is applied to a printing electrode of a non-impact type printer as described above, the anisotropic conductor is required to have a certain degree of mechanical strength. However, when polyimide resin is used as the insulating material 100 for forming the structure, the polyimide resin is varnish-like and can only be produced in the form of a thin film even if cast. Therefore, there is a problem that a thick anisotropic conductor having mechanical strength that can be used as a printing electrode of a non-impact type printer cannot be manufactured.

On the other hand, in order to impart mechanical strength to the anisotropic conductor, it is conceivable to select, for example, an epoxy resin or the like that can form a thick structure as the insulating material 100 forming the structure.

However, as mentioned above, when the anisotropic conductor is applied to the printing electrode of a non-impact type printer,
Since one surface of the anisotropic conductor comes into contact with the heat generating layer of the ink medium, its surface temperature reaches as high as 300 to 400°C. Therefore, the insulating material 1 for forming the structure
If, for example, epoxy resin or the like is used as 00, a problem arises in terms of heat resistance.

[Means to solve the problem]

Therefore, the present invention was made to solve the problems of the prior art described above, and by using a linear conductor as the conductor, the conductor has low conduction resistance and contact resistance, and has strength. Not only does the resistance value remain stable even when external force is applied or rubbed, but the conductor changes little over time, and there are no size restrictions, allowing conductors to be arranged densely and regularly. Anisotropic conductors that can use insulators can be manufactured using simple manufacturing equipment, which not only reduces costs but also provides the heat resistance and mechanical strength required for anisotropic conductors. It is an object of the present invention to provide an anisotropic conductor and a method for manufacturing the same that can satisfy the requirements.

That is, as shown in FIG. 1, the anisotropic conductor according to the present invention is an adhesive that is applied onto an electrode for electrostatic flocking and is removed after the insulating material 3 forming the structure has hardened. An adhesive layer 4, a large number of linear conductors 2.2 that are electrostatically flocked to the adhesive layer 4, and the flocked linear conductors 2.2...
・A structure in which the linear conductors 2.2... are filled and hardened between the spaces, and are oriented in the thickness direction, and both ends of the linear conductors 2.2... are exposed from both the front and back surfaces. comprising an insulating material 3 for forming the structure, the insulating material 3 for forming the structure being made of a plurality of different types of insulating materials,
The structure is constructed to have multiple layers.

As shown in FIG. 2(a), the first manufacturing method of this anisotropic conductor includes an adhesive application step A1 of applying an adhesive on an electrode for electrostatic flocking, and An electrostatic flocking step A2 in which a large number of linear conductors are electrostatically flocked onto the adhesive layer applied on the electrode for electrostatic flocking, and a plurality of linear conductors are flocked between the adhesive layer on the electrode for electrostatic flocking. An insulating structure forming step A3 of filling and curing the insulating material in a layered manner to form a plurality of insulating structures 3 in a layered manner, and removing an electrode for electrostatic flocking stuck to one side of the insulating structure. Thereafter, a polishing step A4 is performed in which both the front and back surfaces of the insulating structure are polished to expose both ends of the linear conductor from both the front and back surfaces of the insulating structure.

Moreover, as a second manufacturing method of this anisotropic conductor, the second
As shown in FIG. Electrostatic flocking step B2 of electrostatically flocking the linear conductor having the above-mentioned properties, and applying a magnetic field to the linear conductor flocked on the adhesive layer on the electrostatic flocking electrode while the hot melt adhesive is softened. Magnetic field application step B improves the uprightness of the linear conductor by
3, an insulating structure forming step of filling and curing a plurality of insulating materials in layers between the linear conductors flocked to the adhesive layer on the electrostatic flocking electrode to form a plurality of insulating structures in layers. B4
After removing the electrostatic flocking electrode fixed to one side of the insulating structure, both the front and back sides of the insulating structure are polished to expose both ends of the linear conductor from both the front and back sides of the insulating structure. It consists of a polishing step B5.

Furthermore, as a third manufacturing method of this anisotropic conductor, as shown in FIG. A flocking position regulating member laying step C2 of laying a flocking position regulating member for flocking the linear conductor according to a predetermined pattern on the adhesive layer applied on the electrode for electrostatic flocking; An electrostatic flocking step C3 in which a large number of linear conductors are electrostatically flocked on the adhesive layer, and a plurality of insulating materials are inserted between the linear conductors flocked on the adhesive layer on the electrostatic flocking electrode. Insulating structure forming step C4 in which a plurality of insulating structures are laminated by filling and curing in layers, and after removing the electrostatic flocking electrode fixed to one side of the insulating structure, It consists of a polishing step C5 in which both the front and back surfaces of the insulating structure are polished to expose both ends of the linear conductor from both the front and back surfaces of the insulating structure.

Furthermore, as a fourth manufacturing method of this anisotropic conductor, as shown in FIG. 2(d), an adhesive application step D1 of applying a hot melt adhesive onto an electrode for electrostatic flocking; A flocking position regulating member laying step D2 for laying a flocking position regulating member for flocking linear conductors according to a predetermined pattern on the adhesive layer applied on the electrostatic flocking electrode; and an electrostatic flocking electrode. An electrostatic flocking process D3 in which a large number of magnetic linear conductors are electrostatically flocked to the adhesive layer applied on the adhesive layer, and the adhesive on the electrode for electrostatic flocking is applied in a state where the hot melt adhesive is softened. A magnetic field application process D4 of improving the uprightness of the linear conductor by applying a magnetic field to the linear conductor flocked on the layer, and a step D4 of applying a magnetic field to the linear conductor flocked on the adhesive layer on the electrostatic flocking electrode. Insulating substrate forming step D, in which a plurality of insulating materials are filled and cured in layers, and a plurality of insulating structures are laminated.
Step 5: After removing the electrostatic flocking electrode fixed to one side of the insulating substrate, both the front and back sides of the insulating structure are polished to expose both ends of the linear conductor from both the front and back sides of the insulating structure. It consists of a polishing step D6.

In such technical means, as the plurality of insulating materials forming the insulating structure, an appropriate combination of a plurality of synthetic resins such as silicone rubber, epoxy resin, and polyimide resin is used. However, in addition to this, other materials may be used in combination as long as they have good adhesion to the metal used as the linear conductor and can be molded into the specified shape by casting. Of course.

Further, by using, for example, a slurry of ceramics or glass as a part of the insulating structure, an anisotropic conductor having heat resistance can be manufactured. Furthermore, in order to improve the slidability of the insulating structure, an epoxy resin mixed with, for example, Teflon powder may be used on the surface of the insulating structure.

In addition, as the adhesive, a hot melt adhesive is used, but in the claimed invention that does not require a hot melt adhesive, the invention is not necessarily limited to this, and commonly used adhesives are used. An adhesive or a tack sheet may be used as the adhesive layer.

Further, as the linear conductor, one made of short metal fibers, carbon fiber, or the like is used. From the viewpoint of lowering the resistance of the anisotropic conductor, this linear conductor may be made of metals with low resistivity such as copper, aluminum, silver, or alloys of these materials. sex,
From a reasonable price point, for example, iron, nickel, tin,
Cobalt or alloys thereof (Ni-Co, Co-3
n, stainless steel, bronze (Cu-8n), brass (Cu-Z
n), Cu-Be, phosphor bronze, nickel silver (Cu-Ni-
Zn), Dvar (Ni-Co-Fe).

Cu-Fe, Fe-Ni, etc.) can be selected.

Further, the length and thickness of the linear conductor are determined in consideration of the characteristics of the anisotropic conductor.

In addition, if the above-mentioned linear conductor is required to have magnetism, any magnetic metal such as nickel, iron, ferrite, or martensitic stainless steel can be used as is. Even non-magnetic metals can be used by plating the surface with magnetic nickel, iron, or the like.

Furthermore, by plating the surface of the linear conductor with gold, tin, etc., the corrosion resistance of the contact can be improved and the contact resistance can also be reduced. Furthermore, by applying insulation treatment to the surfaces of the linear conductors as necessary, it is possible to prevent conduction in the planar direction due to the linear conductors coming into contact with each other.

The methods for producing the short metal fibers include a melt spinning method in which molten metal is jet-sprayed from a thin nozzle onto a roll rotating at high speed, a method in which long metal fibers are produced by pultrusion molding using a wire drawing method, and then separated. A method of shearing the plate material, a method of directly generating it from the base material by chatter vibration cutting method, etc. may be selected as appropriate.

In addition, as a method of electrostatically flocking the linear conductor to the adhesive layer, any method may be selected as appropriate as long as the electrically charged linear conductor is flung toward the adhesive layer by the action of an electrostatic field. . In this case, the flying direction of the linear conductor may be selected as appropriate, such as the down method in which it flies from above to below, the up method in which it flies from below to above, or the side method in which it flies in the horizontal direction. From the viewpoint of reducing loss and facilitating recovery, the up method is preferable.

[Effect]

According to the above-mentioned technical means, since the linear conductor is electrostatically flocked to the adhesive layer, it is possible to easily flock the linear conductor in an upright state. Even when an insulating material is filled and cured between the layers, the linear conductor can be oriented in the thickness direction of the insulating structure, and the linear conductor ensures conductivity only in the thickness direction of the anisotropic conductor. In addition, it is possible to prevent conduction in the plane direction of the anisotropic conductor.

In addition, since the insulating structure is formed by electrostatically flocking linear conductors onto the adhesive layer and filling and curing the insulating material between the linear conductors, the material of the insulating structure is particularly limited. Moreover, the anisotropic conductor can be formed into any shape.

Furthermore, since anisotropic conductors mainly consist of an electrostatic flocking process, an insulating structure formation process, and a polishing process, they can be manufactured using simple manufacturing equipment and in a relatively short time, reducing costs. becomes possible.

In addition, even when linear conductors are arranged regularly, it is only necessary to lay a flocking position regulating member on the adhesive layer prior to the electrostatic flocking process, and it is possible to arrange the linear conductors regularly in a very simple process. Direct conductors can also be produced. Further, by using the flocking position regulating member, it is possible to prevent the linear conductor from adhering to the adhesive layer horizontally, so that insulation in the plane direction can be maintained.

Furthermore, since the insulating material for forming the structure is made of a plurality of different types of insulating materials, and the structure is configured to have a plurality of layers, the anisotropic conductor has, for example, heat resistance. When both mechanical strength is required, an insulating material with high heat resistance and an insulating material with excellent mechanical strength are placed on the side where the insulating material with high heat resistance is required. By laminating and using them in such a manner, it is possible to provide an anisotropic conductor having excellent heat resistance, mechanical strength, and the like.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, an anisotropic conductor and a manufacturing method thereof according to the present invention will be described in detail based on embodiments shown in the accompanying drawings.

Example 1 FIGS. 3 and 4 show an example of an anisotropic conductor according to the present invention.

In the figure, 1 indicates an anisotropic conductor, which is applied onto the electrode for electrostatic flocking and is removed after the insulating material 3 forming the structure has hardened. adhesive layer 4, a large number of short metal fibers 2.2 as linear conductors that are electrostatically flocked to this adhesive layer 4, and flocked short metal fibers 2.2... Filled and hardened between
An insulating material for forming a structure in which short metal fibers 2.2... are oriented in the thickness direction, and both ends of the short metal fibers 2.2... are exposed from both the front and back surfaces. 3, the insulating material for forming the structure is composed of a plurality of insulating materials 3a and 3b of different types, and the structure is configured to have a plurality of layers.

A plurality of short metal fibers 2.2... form an aggregate, and as shown in FIG. 3, these short metal fibers 2.2... They are arranged in a pattern on the surface of the base.

In this embodiment, as the insulating material forming the insulating substrate 3, a polyimide resin 3a having a thickness of 30 to 80 μm and an epoxy resin 3b having a thickness of 900 to 950 μm are used in a laminated manner.

Further, as the metal short fibers 2, for example, stainless steel wires cut into predetermined lengths were used, and the average length and thickness of the metal short fibers 2 was 1.2 mm and 50 μm.

Next, a method for manufacturing the above-mentioned anisotropic conductor will be explained.

First, an adhesive application step is performed to apply an adhesive onto the electrode for electrostatic flocking. That is, as shown in FIG. 5(a),
An aluminum plate 10 as an electrode formed into a rectangular shape of a predetermined size is prepared, and a conductive hot melt adhesive 4 is applied onto the aluminum plate 10. In this example, as the conductive hot melt adhesive 4, 75w of electrolytic silver powder of 200 mesh or less is added to the polyamide hot melt adhesive 4.
A mixture of t% is used. Further, as a method of applying the hot melt adhesive 4, a roller coater is used, which has grooves on the surface of the roller to regulate the thickness of the coating film, and is capable of applying the adhesive 4 to a uniform thickness. Aluminum plate 1
conductive hot melt adhesive to a thickness of 40 μm on top of the
Apply.

Next, a flocking position regulating member laying step is performed in which a flocking position regulating member for flocking the linear conductors according to a predetermined pattern is laid on the adhesive layer applied on the electrostatic flocking electrode. In this flocking position regulating member laying process, as shown in FIG. 5(b), a flocking position regulating sheet 11 for flocking the short metal fibers 2 at predetermined positions is laid on the aluminum plate 10. This flocking position regulation sheet 1
1, as shown in FIG. 6, for example, photosensitive polyvinyl alcohol resin is exposed to light according to a predetermined pattern to form square holes 12, 12, . . . for regulating the position of flocking.
・ are used, which are drilled in the shape of the base at a predetermined pitch. In this example, as the above-mentioned flocking position regulating sheet 11, a 100-μm-thick one in which square-shaped holes 12, 12, each side of which is 300 μm on a side, are bored at a pitch of 500 μm in the shape of a grid in the substrate was used. .

Thereafter, as shown in FIG. 5(C), an electrostatic flocking process is performed in which a large number of magnetic linear conductors are electrostatically flocked onto the adhesive layer coated on the electrostatic flocking electrode. The electrostatic flocking method used in this short metal fiber flocking process is the so-called up method, and as shown in FIG. A high-voltage generator 14 consisting of a high-voltage power supply is connected to.

Further, above the high voltage electrode 13, an aluminum plate 10 as a ground electrode facing the high voltage electrode 13 is placed at an appropriate distance (17 cm in this embodiment) via an acrylic cover C. A large number of short metal fibers on 13 2.2.
...is placed. In addition, in FIG. 7, D indicates an insulating base.

Further, a silicon rubber heater 15 is placed on the top of the aluminum plate 10, and the silicon rubber heater 15 is energized to generate heat to soften the hot melt adhesive 4 applied on the aluminum plate 10. let Then, by applying a high voltage (approximately +27'KV in this example) from the high voltage generator 14 to the high voltage electrode 13 for a predetermined time (3 minutes in this example), the short metal fibers on the high voltage electrode 13 are At the same time as charging the short metal fibers 2.2, an electric field E acting in the vertical direction is formed between the high voltage electrode 13 and the aluminum plate 10 serving as a ground electrode, and the metal short fibers 2.2 are charged along the electric field E. ... is flown toward the adhesive layer 4 side of the aluminum plate 10, and short metal fibers 2.2... are flocked onto the adhesive layer 4 by electrostatic force. Thereafter, while applying voltage to the high-voltage electrode 13, electricity to the silicon rubber heater 15 is stopped to cool the aluminum plate IO, the hot melt adhesive 4 is hardened, and the short metal fibers 2.2... It is fixed to the adhesive layer 4.

During the electrostatic flocking, on the surface side of the adhesive layer 4,
Since the flocking position regulating sheet 11 is arranged, the short metal fibers 2.2... are flocked only through the openings 12, 12... of the flocking position regulating sheet 11. the result,
As shown in FIG. 5(c), the short metal fibers 2.2... are implanted in openings 12.12... of the flocking position regulating sheet 11 in a relatively upright state. Ru.

In this short metal fiber flocking process, since the direction of action of the electric field E is perpendicular to the adhesive layer 4, the short metal fibers 2.2... flying along the direction of action of the electric field E are attached to the adhesive layer 4. The hair will be densely implanted in an upright position.

In addition, since the adhesive layer 4 on which the metal short fibers 2.2... are flocked has conductivity, the electric charges charged on the metal short fibers 2.2... during electrostatic flocking are as follows. Short metal fiber 2
．． 2... are flocked to the adhesive layer 4, they escape to the ground via the adhesive layer 4 and the aluminum plate 10 and are neutralized.

Therefore, as in the case where the short metal fibers 2.2... are flocked while being charged, the electric charges charged at the tips of the short metal fibers 2.2... repel each other, and the short metal fibers 2.2... 2・
It is possible to prevent the uprightness of ... from being disturbed.

In addition, in the short metal fibers 2.2..., charge polarization occurs again due to electrostatic induction phenomenon after flocking, but the adhesive layer 4
Since the charge on the side escapes to the ground and is neutralized, the lower end of the flocked short metal fibers 2.2...
The short metal fibers 2.2... can maintain their uprightness from this point as well.

Incidentally, the electrostatic flocking method is not limited to the above method, but for example, the so-called down method shown in FIG. A high-voltage electrode 16 made of metal net or the like is arranged in a substantially horizontal direction on the lower surface of the hopper 19 in which ... is accommodated, and a ground electrode 17 facing the high-voltage electrode 16 is arranged below the high-voltage electrode 16. By applying a high voltage from the high voltage generator 18 to the high voltage electrode 16, an electric field E acting vertically between the picture electrodes 16 and 17 is formed, and the adhesive layer 4 disposed on the ground electrode 17 side is formed. The short metal fibers 2.2 for flocking are implanted in the hair, or the so-called side method shown in FIG. 9 is used, specifically, the short metal fibers 2.2 for flocking
. . . A high voltage electrode 20 is placed on the lower side of the hopper 19 that is accommodated.
and a ground electrode 21 are arranged to face each other along the substantially vertical direction, and by applying a high voltage from a high voltage generator 22 to the high voltage electrode 20, an electric field E acting in the horizontal direction is formed between the picture electrodes 20 and 21. , metal short fibers 2.2... falling from the hopper 19 onto the adhesive layer 4 disposed on the ground electrode 21 side are approximately 9
The hair may be transplanted by changing the direction by 0°.

Thereafter, a magnetic field application step is performed to improve the uprightness of the linear conductor by applying a magnetic field to the linear conductor flocked on the adhesive layer on the electrostatic flocking electrode. That is,
The aluminum plate 10 on which the short metal fibers 2, 2, .

As shown in FIG. 1O, this magnetic field generating device 23 includes a pair of permanent magnets 25 and 26 fixed to mutually parallel opposing surfaces of a yoke 24 having a U-shaped cross section.
A uniform magnetic field H is generated between the opposing N and S poles of both permanent magnets 25 and 26. By supporting the aluminum plate 10 on which the short metal fibers 2.2 are flocked by the support member 27, both permanent magnets 25.
The silicon rubber heater 15 is placed between the opposed north and south poles of the aluminum plate 10 and placed on the back surface of the aluminum plate 10.

Next, the silicon rubber heater 15 is energized to heat the aluminum plate 10 and soften the hot melt adhesive 4 coated on the aluminum plate 10.

By holding this state for several minutes, the short metal fibers 2
．． 2... becomes able to move freely to some extent as the hot melt adhesive layer 4 softens, and the magnetic field generating device 23
The fibers are oriented along the magnetic field H formed by the fibers, and stand upright within the holes 12, 12, . . . of the flocking position regulating sheet 11. Thereafter, the power supply to the silicon rubber heater 15 is stopped to cool the aluminum plate IO, the hot melt adhesive layer 4 applied on the aluminum plate 10 is hardened, and the short metal fibers 2.2... are erected. keep it in the same state. By doing so, as shown in No. 59 (d), the uprightness of the short metal fibers 2.2... can be further improved.

The inventor of the present invention has discovered that the metal short fibers 2.2 obtained by the above-mentioned magnetic field application process are
In order to confirm the improvement in the uprightness of the short metal fibers 2.2, we observed the flocked state of the short metal fibers 2.2 after the magnetic field application process using a microscope. was found to have definitely improved.

In addition, in this embodiment, as the magnetic field generating device 23,
A device that generates a uniform magnetic field of about 500 [gauss] was used.

Furthermore, filling and hardening a plurality of insulating materials in layers between the linear conductors flocked on the adhesive layer on the electrostatic flocking electrode,
An insulating substrate forming step is performed in which a plurality of insulating substrates are laminated. At that time, prior to filling with insulating synthetic resin,
The flocked part is removed from the magnetic field generator 23, and the short metal fiber 2 is
．． 2... and the polyimide resin constituting the first layer of the insulating substrate 3a, a titanate coupling agent (manufactured by Ajinomoto Co., Inc.: 138S3) is used to suppress air bubbles generated at the contact area between the polyimide resin and the first layer of the insulating substrate 3a.
38X) or a silane coupling agent in an amount of 0.5 to 1.0% is preferably added to the polyimide resin. Then, as shown in FIG. 5(e), a casting mold 30 is attached around the flocked area, and polyimide varnish 3a (Kanebo N5C
I! A 20% diluted IP630 in NMP) was cast and defoamed, and the polyimide varnish 3a was cured.

Next, as shown in FIG. 5(f), epoxy resin 3b (CECO9IC: manufactured by Hitachi Chemical Co., Ltd.) is poured onto the polyimide varnish 3a that has been cast and cured in the formwork 30 as described above. The epoxy resin 3b is foamed and cured.

Finally, after removing the electrostatic flocking electrode fixed to one side of the insulating substrate, both the front and back sides of the insulating substrate are polished.
A polishing step is performed to expose both ends of the linear conductor from both the front and back surfaces of the insulating substrate. That is, the above epoxy resin 3b
After curing, remove the flocked part from the aluminum plate 10, and sequentially coat the top and bottom of the insulating substrate 3 with #500, #1000, and #20.
Polished with 00 sandpaper and polyimide face 3a
And while smoothing the surface of the epoxy resin 3b, the end faces of the nickel short metal fibers 2.2... are exposed from the surface, and as shown in the 5th WJ (g), the polyimide varnish 3a and the epoxy resin 3b are coated. An anisotropic conductor 1 was manufactured by laminating the following materials in a layered manner. At this time, the adhesive layer 4 applied on the aluminum plate 10 is also removed from the surface of the insulating substrate 3 by the polishing process.

The anisotropic conductor 1 constructed as described above is constructed by laminating a polyimide varnish 3a with excellent heat resistance and an epoxy resin 3b which can be formed into a thick layer and has excellent mechanical strength. Therefore, it is possible to provide an anisotropic conductor 1 that has both heat resistance and mechanical strength.

The thickness of the anisotropic conductor 1 manufactured in this way is 0.
9 mm, and stainless steel short metal fibers 2.2, which are linear conductors, are arranged on the surface of the insulating substrate 3 at a pitch of 500 um.
... were arranged in a pattern on the base.

Next, the resistance values in the thickness direction of the anisotropic conductor 1 and between adjacent conductors were measured using a digital voltmeter.

The Hori constant of the resistance value in the thickness direction of the anisotropic conductor 1 is as shown in FIG. In addition to placing the body 1 on the anisotropic conductor 1, a wire with a diameter of 1.3 mm (area of 1 c
Place the end face of the metal rod 33 of m2) on the conductor pattern 32.
The resistance value between the conductor pattern 32 and the metal rod 33 was measured using a digital voltmeter, and the resistance value when the anisotropic conductor 1 was not interposed between the conductor pattern 32 and the metal rod 33 was subtracted.

Furthermore, the resistance value between adjacent conductors of the anisotropic conductor l is the first
As shown in Figure 2, two electrodes 34 and 35 each having a width of 1 cm are placed in the plane direction on the prototype anisotropic conductor L with an insulating tape 36 having a thickness of 0.1 mm interposed therebetween. The resistance value was determined by measuring the resistance value between .

As a result of the above measurement, the resistance value in the thickness direction of the anisotropic conductor 1 and between adjacent linear conductors was approximately 20 mΩ and infinite.

In the above embodiment, as the insulating material constituting the anisotropic conductor 1, the polyimide varnish 3a is first filled and cured, and then the epoxy resin 3b is filled and cured, so that the polyimide varnish 3a and the epoxy resin 3b are combined. Although the case of laminated formation has been described, it is not limited to this.
First, the epoxy resin 3b is filled and cured, then the polyimide varnish 3a is filled and cured, and the polyimide varnish 3a is
and the epoxy resin 3b may be formed in a laminated manner.

Embodiment 2 FIGS. 13 and 14 show an anisotropic conductor according to a second embodiment of the present invention, and the same parts as in the previous embodiment are denoted by the same reference numerals. In this example,
Stainless steel mesh is used as a flocking position regulating member to regularly arrange linear conductors at high density, and as an insulating substrate, Teflon powder is applied to the surface to improve surface sliding properties. Mixed epoxy resin 3C is laminated.

The anisotropic conductor according to this example is manufactured as shown in FIG. 15.

First, as shown in FIG. 15(a), an aluminum plate 10 as an electrode formed in a rectangular shape of a predetermined size is prepared.
A rectangular opening 40 is formed in this aluminum plate 10 as shown in FIG. Then, as shown in FIG. 15(b) and FIG. 18, on the surface side of the opening 40 of this aluminum plate 10, the pitch is 63 μm, and the size of the opening 41a is 40 μm.
A polyamide hot-melt adhesive is attached with a m square stainless steel mesh 41 (shown in Figure 17) and a conductive coating agent is applied to the back side of the opening 40 to adjust the surface resistance to 101-10°Ω. Attach the agent sheet 42.

In this example, Ni metal short fibers having an average length and thickness of 1.2 mm and 20 μm were used as the metal short fibers 2.

Next, the surface of the short metal fiber 2 is coated with electroless copper plating.
A copper plating layer with a thickness of 1 to 3 μm is provided, and then the short metal fibers 2 are placed in a solution of 10 g/l of potassium persulfate and 50 g/β of sodium hydroxide heated to 102 to 110°C for 3 to 10 minutes. As shown in FIG. 19, the copper plating layer was oxidized to form a high resistance layer 43 made of cupric oxide.

Thereafter, in the same manner as in Example 1, the short metal fibers 2.2... are placed in the flocking apparatus shown in FIG. 7, and the electrostatic flocking process is performed. At this time, the silicon rubber heater 15 is energized to generate heat to soften the hot melt adhesive sheet 42, and a high voltage (approximately +22 KV in this embodiment) is applied to the high voltage electrode 13 from the high voltage generator 14 for a predetermined period of time. In the example, the electrostatic flocking process is performed by applying the voltage for 3 minutes. By doing so, the short metal fibers 2.2... can be implanted in the opening 41a of the stainless steel mesh 41 at high density and at a fine pitch.

Next, in the same manner as in Example 1, a magnetic field application step is performed to improve the uprightness of the flocked portion.

Furthermore, an insulating substrate forming step is performed in the same manner as in Example 1.

That is, as shown in FIG. 15(e), the aluminum plate lO
polyimide varnish 3a (Kanebo NSC)
Polyimide varnish 3a is cured by casting and degassing a product obtained by diluting 20% of polyimide varnish 3a with the solvent NMP.

Thereafter, as shown in FIG. 15(f), epoxy resin 3b (CECO91C: manufactured by Hitachi Chemical Co., Ltd.) is cast and defoamed onto the polyimide varnish 3a that has been cast and cured in the mold 30 as described above. Then, the epoxy resin 3b is cured.

Next, as shown in FIG. 15(g), epoxy resin 3c (CECO91C
: manufactured by Hitachi Chemical Co., Ltd.) is cast and defoamed, and this epoxy resin 3c is cured.

Finally, the flocked portion is taken out from the aluminum plate 10, and the upper and lower surfaces of the insulating substrate 3 are sequentially polished using a single-sided lapping machine to make the surface smooth and insulating. Short metal fibers 2 from the surface of the substrate 3.
2... are exposed, and as shown in FIG. 13, an anisotropic conductor 1 having an insulating substrate 3 made of polyimide varnish 3a and epoxy resins 3a, 3b is manufactured.

In this embodiment, the surface of the anisotropic conductor 1 is made of epoxy resin 3c mixed with Teflon powder,
Since the epoxy resin 3c mixed with Teflon powder has a low surface contact resistance, it is possible to improve the slidability of the surface of the anisotropic conductor 1.

The thickness of the anisotropic conductor 1 manufactured in this way is 0.
The surface of the insulating substrate 3 has an average of 12 wires/
Short metal fibers made of nickel, which are linear conductors, were arranged in the shape of a grid on the substrate at a pitch of mm.

Next, when the resistance values in the thickness direction of the anisotropic conductor 1 and between adjacent conductors were measured using a digital voltmeter, the resistance values in the thickness direction of the anisotropic conductor 1 and between adjacent linear conductors were measured. was approximately 20 mΩ and infinite.

In addition, measurements were conducted to examine the temperature rise of the anisotropic conductor 1 when a large current was continuously passed through the metal end fibers 2, 2, . . . of the anisotropic conductor 1. As shown in FIG. 20, this temperature measurement is carried out by providing a conductor pattern 51 with a width of 3 cm on an insulating substrate 50, placing the prototype anisotropic conductor l on it, and then At a position corresponding to the conductor pattern 51 on the conductor 1, a diameter 1.3 mm (area 1 c
m2) is placed on the end face of the metal rod 52, and the conductor pattern 51 is placed.
A current of 4 A is passed between the metal rod 52 and the metal rod 52 via a power source 53, an ammeter 54, and a constant voltage load device 55.
The temperatures of the upper end, the surface of the anisotropic conductor 1 on the conductor pattern 51, and the surface of the anisotropic conductor 1 at a position away from the conductor pattern 51 were measured.

As a result, the temperature difference between the surface of the anisotropic conductor 1 on the conductor pattern 51 and the upper end Td of the metal rod 52 was 24°C.

〔Effect of the invention〕

This invention consists of the above-mentioned structure and operation, and according to the anisotropic conductor and the manufacturing method thereof according to claims 1 to 8, since a linear conductor is used as the conductor, the conductor is not electrically conductive. We manufacture anisotropic conductors that have low resistance and contact resistance, have strong conductors, and have stable resistance values even when external force is applied or rubbed, and the conductors change little over time. Not only can the wire conductors be electrostatically flocked to the adhesive layer, so the wire conductors can be easily flocked in an upright state, and there is no insulation between the wire conductors. Even when the material is filled and cured, the linear conductor can be oriented in the thickness direction of the insulating substrate, and the linear conductor can ensure conductivity only in the thickness direction of the anisotropic conductor. Moreover, since the anisotropic conductor mainly consists of an electrostatic flocking process, an insulating substrate forming process, a polishing process, etc., it can be manufactured using a simple manufacturing apparatus, and costs can be reduced. Furthermore, since the insulating material filled and hardened between the electrostatically flocked linear conductors is not particularly limited, it is possible to manufacture anisotropic conductors of arbitrary shapes and large areas.

Further, according to the method for manufacturing an anisotropic conductor according to claim 6, after electrostatic flocking, a uniform magnetic field is applied to the magnetic linear conductor, thereby improving the uprightness of the linear conductor. Therefore, even when the linear conductors are arranged at high density, the insulating properties of the anisotropic conductor in the plane direction can be reliably maintained.

Furthermore, according to the method for producing an anisotropic conductor according to claim 6 or 7, the flocking position regulating member is laid on the surface of the adhesive layer prior to electrostatic flocking. An anisotropic conductor in which conductors are regularly arranged can be manufactured extremely easily.

Furthermore, according to the method for manufacturing an anisotropic conductor as set forth in claim 8, it is possible to manufacture an anisotropic conductor that has both the effects of the above claims 6 and 7.

In this way, since a plurality of insulating materials are laminated, it is possible to provide the anisotropic conductor with multiple functions. For example, it is possible to improve heat resistance, sliding properties, etc.

In addition, since the insulating material for forming the structure is made of a plurality of different types of insulating materials, and the structure is configured to have a plurality of layers, the anisotropic conductor has, for example, heat resistance and mechanical properties. When both mechanical strength and mechanical strength are required, an anisotropic material that satisfies both heat resistance and mechanical strength can be created by laminating an insulating material with excellent heat resistance and an insulating material with excellent mechanical strength. A conductor can be provided.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an anisotropic conductor according to the present invention, and FIG.
Figures (a) to (cl) are process diagrams showing the method for manufacturing an anisotropic conductor according to the present invention, and Figures 3 and 4 are perspective views showing an embodiment of the anisotropic conductor according to the present invention. 5(a) to 5(g) are sectional views showing the manufacturing process of the anisotropic conductor, FIG. 6 is a plan view showing the flocking position regulating sheet, and FIG. 7 is the electrostatic flocking device. Fig. 8 and 9 are block diagrams showing other embodiments of the electrostatic flocking device, Fig. 1θ is a block diagram showing a magnetic field generating device, and Figs. 13 and 14 are perspective views and cross-sectional views showing other embodiments of the anisotropic conductor according to the present invention, respectively, and FIGS. (h) is a cross-sectional view showing the manufacturing process of the anisotropic conductor according to the present invention, FIG. 16 is a perspective view showing an aluminum plate, FIG. 17 is a plan view showing a stainless steel mesh, and FIG. 18 is an aluminum plate. Fig. 19(a) is a perspective view showing the state in which the stainless steel mesh and adhesive sheet are attached to the
b) is an external perspective view and a cross-sectional view showing an insulating layer of short metal fibers, FIG. 20 is a perspective view showing an apparatus for measuring the temperature rise of an anisotropic conductor, and FIG. 21 is a difference according to the applicant's proposal. FIG. 2 is a conceptual diagram showing a directional conductor. [Explanation of symbols] 1...Anisotropic conductor 2...Metal short fibers 3...Insulating structure 4...Adhesive patent Applicant Fuji Xerox Co., Ltd. Representative Patent attorney Satoshi Nakamura Hiroshi (1 other person) 2 Short metal fiber 3 Insulating structure 4 Adhesive Figure 15 Figure 16 Figure 17 (a) Figure 18 Figure 19 (b)

Claims (8)

[Claims] (1) An adhesive layer that is applied on the electrode for electrostatic flocking and is removed after the insulating material forming the structure has hardened, and a large number of wires that are electrostatically flocked to this adhesive layer. It is filled and hardened between the conductor and the flocked linear conductor, forming a structure in which the linear conductor is oriented in the thickness direction and both ends of the linear conductor are exposed from both the front and back sides. An anisotropic conductor comprising: an insulating material for forming the structure, wherein the insulating material for forming the structure is made of a plurality of different types of insulating materials, and the structure has a plurality of layers. (2) The anisotropic conductor according to claim 1, wherein the linear conductor is made of short metal fibers. (3) Claim 1 or 2, wherein the linear conductor is made of short metal fibers whose surface is insulated.
Anisotropic conductor described in section. (4) The anisotropic conductor according to any one of claims 1 to 3, wherein the linear conductors are regularly arranged. (5) An adhesive application process of applying adhesive onto the electrode for electrostatic flocking, and an electrostatic process of electrostatic flocking of a large number of linear conductors on the adhesive layer coated on the electrode for electrostatic flocking. The flocking process and the formation of an insulating structure in which multiple insulating materials are filled and cured in layers between the linear conductors that are flocked to the adhesive layer on the electrostatic flocking electrode, and a plurality of insulating structures are laminated. After removing the electrostatic flocking electrode stuck to one side of the insulating structure, both the front and back sides of the insulating structure are polished, and both ends of the linear conductor are removed from both the front and back sides of the insulating structure. A method for manufacturing an anisotropic conductor, comprising a polishing step for exposing. (6) An adhesive coating process in which hot melt adhesive is applied onto the electrode for electrostatic flocking, and a large number of magnetic linear conductors are statically coated on the adhesive layer coated on the electrode for electrostatic flocking. The electrostatic flocking process involves applying a magnetic field to the wire conductor flocked on the adhesive layer on the electrostatic flocking electrode while the hot melt adhesive is softened. A magnetic field application process that improves uprightness is performed, and multiple insulating materials are filled and cured in layers between the linear conductors flocked to the adhesive layer on the electrostatic flocking electrode to form multiple insulating structures. After removing the electrostatic flocking electrode fixed to one side of the insulating structure, the front and back surfaces of the insulating structure are polished to form an insulating structure at both ends of the linear conductor. A method for manufacturing an anisotropic conductor, comprising a polishing step of exposing the body from both the front and back sides. (7) An adhesive application step of applying adhesive on the electrode for electrostatic flocking, and for flocking a linear conductor according to a predetermined pattern on the adhesive layer applied on the electrode for electrostatic flocking. an electrostatic flocking process in which a large number of linear conductors are electrostatically flocked to an adhesive layer coated on an electrode for electrostatic flocking; an insulating structure forming step in which a plurality of insulating materials are filled and cured in layers between the linear conductors flocked on an adhesive layer on an adhesive layer on an electrode, and a plurality of insulating structures are layered; After removing the electrostatic flocking electrode fixed to one side of the body, both the front and back sides of the insulating structure are polished to expose both ends of the linear conductor from both the front and back sides of the insulating structure. A method for manufacturing an anisotropic conductor, characterized by: (8) An adhesive application step of applying hot melt adhesive onto the electrode for electrostatic flocking, and flocking a linear conductor in a predetermined pattern on the adhesive layer applied on the electrode for electrostatic flocking. an electrostatic flocking process in which a large number of magnetic linear conductors are electrostatically flocked to the adhesive layer coated on the electrostatic flocking electrode; A magnetic field application process that improves the uprightness of the linear conductor by applying a magnetic field to the linear conductor flocked to the adhesive layer on the electrostatic flocking electrode while the hot melt adhesive is softened. and an insulating structure forming step in which a plurality of insulating materials are filled and cured in layers between the linear conductors flocked on the adhesive layer on the electrostatic flocking electrode, and a plurality of insulating structures are layered. After removing the electrostatic flocking electrode fixed to one side of the insulating structure, both the front and back sides of the insulating structure are polished to expose both ends of the linear conductor from both the front and back sides of the insulating structure. 1. A method for producing an anisotropic conductor, comprising a polishing step.