JPS62208509A - Manufacture of annular structure for anisotropic conductive sheet - 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 [Industrial Field of Application] The present invention relates to a method for manufacturing an annular structure. More specifically, the present invention relates to a method for manufacturing an annular structure used to manufacture an anisotropically conductive sheet useful as a connector for various electronic components.

[Conventional technology]

A thin sheet that allows electricity to flow freely in the thickness direction but is electrically insulated in the plane direction is called an anisotropic conductive sheet, and by sandwiching and crimping it, it is possible to solder electrical circuit elements together. It is well known that it is useful as a member of various connectors because it can be connected in the same way as a conventional case.

As conventionally known anisotropic conductive sheets, the following various sheets are known. For example, a sheet obtained by adding conductive particles to an insulating elastomer in an amount adjusted so that contact between the particles occurs only when the sheet is compressed; A sheet obtained by holding a linear conductor cut into a certain length in a magnetic field in the thickness direction of the sheet, and then solidifying the matrix liquid (for example, JP-A-53-3339)
(No. 0 Publication); Alternatively, linear conductors cut to a certain length are dispersed in an insulating elastomer in a plasticized state, and then extruded from a nozzle, whereby the linear conductors are oriented in a substantially constant direction in the insulating elastomer. A rod-shaped molded product is made, and then a large number of rod-shaped products molded in this way are stacked to form a block-shaped molded product, which is then sliced in a plane almost perpendicular to the orientation direction of the linear conductors to obtain a sheet-shaped product. (Japanese Unexamined Patent Publication No. 52-65892).

However, all of the conventionally known anisotropic conductive sheets have a problem in that the manufacturing process is complicated and many steps are required to produce the product, resulting in an unavoidably high manufacturing cost. In addition, it is not possible to completely control the conductive particles and linear conductors in the insulating elastomer during the manufacturing process, so the anisotropic conductive sheet obtained from this cannot have a very high conductor density, and as a result, it is difficult to control the conductive particles and linear conductors in the insulating elastomer. Only products with low conduction density and so-called poor electrolytic performance were obtained.

[Problem that the invention seeks to solve]

To this end, the present inventors have proposed a manufacturing method that applies warping technology for warp sizing in the fabric manufacturing process as a manufacturing method that can solve the above problems.
That is, this method applies a liquid insulating material while running at least one linear conductor, dries and solidifies the liquid insulating material to a semi-hardened state, and then forms an anisotropically conductive annular structure by laminating and winding the material. After that, the annular structure is divided and cut along a plane perpendicular to the linear conductor to obtain an anisotropically conductive sheet.

This manufacturing method certainly has the advantage of producing an anisotropic conductive sheet with a very fine arrangement pitch of linear conductors in the insulating material and high electrolytic performance compared to the conventional manufacturing method described above. To manufacture a structure, after applying a liquid insulating material to a linear conductor, it is necessary to roll the insulating material into a ring shape in a so-called semi-hardened state, without completely solidifying it in a dryer. When the applied linear conductors are superimposed, the arrangement pitch of the linear conductors in the annular structure varies depending on the hardening state of the liquid insulating material applied in the previous step.

That is, when looking at the cross section of an annular structure having a hollow hole with a radius R and a thickness t in the radial direction, if the curing conditions are appropriate, a group of linear conductors will form as shown in FIG. 2(A). 10 are uniformly laminated in the annular structure 20, but if the applied liquid insulating material is not sufficiently cured, the linear conductor group 1° is laminated in the annular structure 20 as shown in FIG. 2(B). On the other hand, if the facilitation is sufficient, as shown in FIG. 2(C), the linear conductor group 1o coated with a liquid insulating material is rolled up and laminated, and then the linear conductor group 1o They are not adhered to each other and form layers, making it impossible to obtain a uniform structure.

Therefore, in order to industrially produce an anisotropically conductive sheet with a uniform array of linear conductors from an anisotropically conductive annular structure obtained by the above manufacturing method, there is a problem of lack of stability. have

The present invention solves the problems in the manufacturing method described above, and has the desired size and elasticity, and all the gaps between the constituent linear conductors are filled with a solid insulating material. An object of the present invention is to provide a method for manufacturing an annular structure in which an anisotropic conductive sheet having extremely uniform arrangement intervals can be produced by cutting.

[Means for solving problems]

The object of the present invention is to have a substantially square or rectangular cross-sectional shape in any plane including its axis, and a plurality of linear conductors in a direction perpendicular to the plane are integrated with each other through an insulating material. A method for manufacturing an annular structure in which the linear conductors are wound in an integrated manner, the method being achieved by a method for manufacturing an annular structure, characterized in that the manufacturing method comprises the following steps: .

■ Applying an insulating substance in a viscous liquid state to at least one running linear conductor so that each linear conductor is coated with the insulating substance; ■ (1) above; (2) heating at least one linear conductor coated with an insulating material in step (2); a step of applying an adhesive substance in a viscous liquid state; ■ winding at least one linear conductor to which an adhesive substance has been applied in step (3) in a layered or traversing manner to form an annular structure; the step of forming a body; ■ during step (4) above or during step (4) above;
) heat treatment step that is performed after the completion of the step.

As the adhesive substance applied in step (3) above, the same substance as the insulating substance applied in step (1) may be used.

The present invention will be described below with reference to the accompanying drawings showing an example of an apparatus for carrying out the method for manufacturing an annular structure according to the present invention, and an example of an anisotropic conductive structure and an anisotropic conductive sheet made from the annular structure. details.

FIG. 3(A) shows a perspective view of the annular structure 2o.

FIG. 3(B) shows an anisotropic conductive structure 30 obtained by dividing the annular structure 2o along a plane substantially perpendicular to the arrangement direction of the plurality of linear conductors 10 in the structure. shows.

FIG. 4 is an enlarged view of the anisotropic conductive structure 3o.

Here, the anisotropic conductive structure 3o has a substantially rectangular shape, and the surfaces indicated by 2 and 3 are slightly curved. However, as in the example shown in Figure 3 (A), the radius of curvature of the surface 2 is 30
If a1 or more, 2 and 3 are substantially flat. However, the diameter R of the center hole of the annular structure 20 shown in FIG. It is preferable to select the value of R to be 10C11 or more. Also, the annular structure 2
The wall thickness t of 0 may be arbitrarily selected in consideration of the size of the anisotropically conductive sheet that is the final use.

A plurality of linear conductors 10 pass through the anisotropically conductive structure in parallel along said plane 2.3 and are arranged at regular intervals from each other as shown in FIG. Fourth
As is clear from FIG. 4, which shows the anisotropically conductive structure 30 shown in the figure cut along the linear conductor lO, in the anisotropically conductive structure 30 according to the present invention, the linear conductor 10 The gap between them is filled with a solid insulating substance 5, and there is no gap in the contact area 6 between the insulating substance 5 and the linear conductor 10.

The anisotropically conductive structure 30 is shown in FIGS. 3(B) and 3(C).
), the anisotropic conductive sheet 40 shown in FIG.
is obtained. This anisotropic conductive sheet 40 is shown in FIG. 5(B).
As shown in the cross-sectional view, a plurality of linear conductors 11 and 12 are arranged in parallel to penetrate the anisotropically conductive sheet 40 in the thickness direction, and the gap between adjacent linear conductors 11 and 12 is are uniform and all filled with the insulating material 5. Therefore, even if the thickness of the anisotropically conductive sheet 40 is increased in order to give it elasticity, the conductive fiber density will not decrease and dielectric breakdown between adjacent linear conductors will not occur. The linear conductor 10 used in the annular structure 20 includes, for example, copper, aluminum,
Thin metal wires such as stainless steel, carbon fibers, graphite fibers, synthetic fibers made of conductive polymer materials, synthetic fibers coated or plated with conductive substances such as gold, silver, nickel, etc., or as conductivity imparting agents. Synthetic fibers mixed with carbon blank, metal powder, graphite, etc. can be used.

There are no particular restrictions on the cross-sectional shape and thickness of the linear conductor, and it is sufficient to select an appropriate one depending on the application.
It is also preferable because it has a small surface area and improves adhesiveness with insulating substances. The thickness of the linear conductor is 3 to 300 mm in diameter.
Although it is possible to use a conductor having a diameter of 3 to 100 μm, it is more preferable to use a conductor having a diameter of 3 to 100 μm, considering the ease of handling the linear conductor and the electrical conduction density when used in a connector as a final product.

Next, if the current level of a linear conductor is expressed in terms of volume resistivity, it is 10
-4Ω·1 or less is preferable, and depending on the application, a linear conductor having a more appropriate volume resistivity may be selected and used.

Any of thermosetting resins or thermoplastic resins such as insulating resins, polyamide resins, ABS resins, silicone resins, etc. used in the annular structure according to the present invention and the anisotropically conductive sheet made by cutting it. can be used. However, it is more preferable to use silicone resin in consideration of electrical properties, mechanical properties against compression, etc.

The linear conductors in the insulating material are required to be arranged at regular intervals. The size of the interval, that is, the packing density may be appropriately selected depending on the final use of the anisotropic conductive sheet within a range where adjacent linear conductors do not come into contact with each other. - As an example, when linear conductors with a diameter of 30 μm are used, they can be used at a packing density in the range of 10 to 500 conductors/ram'', and the mechanical properties such as elasticity of the anisotropic conductive sheet can be sufficiently maintained. In order to secure 10 to 200 pieces/
It may be used within the range of m1Iz.

As shown in FIG. 1, the apparatus for carrying out the method of manufacturing an annular structure of the present invention includes a thread alignment process section 50, a liquid insulating material application process section 60, a drying process section 70, and a liquid insulating material regeneration process section. It includes a applying process section 80 and a winding and laminating process section 90. In one embodiment of the annular structure manufacturing apparatus shown in FIG. 1, the thread alignment device 50 has a plurality of linear conductor packages around which the linear conductors 10 are wound. A creel 51 and a batten 52 that ranks and regularly arranges a plurality of linear conductors drawn out from the creel 51.
, a curved line 53 disposed downstream of the batten for arranging a plurality of linear conductors roughly in a sheet shape, and a sheet-shaped linear conductor arranged at predetermined intervals depending on the final use of the annular structure. body 1
8.

Further, in one embodiment of the annular structure manufacturing apparatus shown in FIG. The extruder 61 is provided to apply an insulating substance in a viscous liquid state to the sheet-like linear conductor 18.

The drying process section 70 is disposed downstream of the insulating material coating device to almost completely or completely harden the insulating material on the sheet-like linear conductor 18, and has an electric heater and a circulation system therein. A fan (both not shown) is provided. Note that the dryer may be of any type, such as a hot air type or an infrared type, as long as it is a non-contact type.

The liquid insulating material reapplying process section 8o consists of an upper and lower pair of feed rolls 81, delivery rolls 83, liquid insulating material deposition rolls 82, and liquid insulating material baths 84. The tension of the sheet-shaped linear conductor is adjusted by the rotation ratio of the feed roll 81 and the delivery roll 83, and
The amount of the insulating material deposited is controlled by the squeeze pressure of the liquid insulating material depositing rolls 82 and 83.

The winding and laminating process section 90 includes a rotating device (not shown) that removably holds the winding bobbin 91 and a driving device that drives the rotating device. If the winding bobbin 91 is a bobbin having flanges 93 and 94 on both sides as illustrated in FIG.
It is useful for regularly winding up 0 and forming an annular structure 2o with a beautiful end surface. At this time, one flange 94 is formed to be removable, and the outer diameter of the winding part 92 of the bobbin 91 is set to 6.
It is more preferable to set it to 0 [.

A speed change that adjusts the rotational speed of the rotating device so as to keep the running speed and torque of the sheet-like linear structure 100 constant regardless of changes in the outer diameter of the annular structure 20 during lamination and winding in the drive device. Preferably, a mechanism (not shown) is provided.

As described above, in the manufacturing method according to the present invention, the sheet-like linear power transmitter 100 coated with a liquid insulating material is completely cured, and then laminated again with the liquid insulating material being re-attached to its surface. The annular structure 20 is thus formed.

After the bobbin is removed, the annular structure 20 is heated and left for about 48 hours, during which time the insulating material f5 is completely cured. However, the heat treatment may be performed while winding the sheet-like linear conductor in the winding and laminating process section 90.

The re-deposited liquid insulating material is laminated in an uncured state and then completely cured, so that each layer of the insulating material is completely bonded.

The method for manufacturing the annular structure described with reference to FIG. 1 is a method in which an insulating material is applied to a plurality of linear conductors while running them at predetermined intervals, and then the wires are wound into layers.
The insulating material may be applied in two stages while one or several linear conductors are running, and then wound up while being traversed to a predetermined width. In this case as well, it is important that the second insulating material is applied after the first insulating material is completely cured together with the linear conductor.

In the method for manufacturing an annular structure according to the present invention, the second insulating material used is usually the same material as the first insulating material applied.

However, since the main purpose of the second insulating material is adhesion, other adhesive materials may be used as long as they do not impede the insulation properties of the final product, the anisotropically conductive sheet.

Further, as the means for applying the first insulating substance and the means for applying the second insulating substance, means other than the means explained based on FIG. 1 may be used. For example, a doctor knife may be used to apply the first insulating material, or a dipping method may be used.

When carrying out the method for manufacturing an annular structure according to the present invention, the width D of the annular structure (Fig. 3 ( A) can be arbitrarily selected. Warping techniques used in the weaving process can easily obtain a width of 2 to 3 meters. On the other hand, the thickness t (FIG. 3(A)) of the annular portion can also be arbitrarily selected by changing the number of windings. Further, the inner diameter R of the annular structure can be easily increased to about 2 m using a partial warping machine used in the weaving process. Thus, by using the annular structure obtained by the manufacturing method of the present invention, an anisotropically conductive sheet having a desired size can be obtained.

〔Example〕

Hereinafter, specific examples regarding the method for manufacturing an anisotropically conductive annular structure according to the present invention will be shown, and a performance comparison with comparative examples will also be shown.

Example 1 A ring-shaped structure was prepared under the following conditions using an apparatus similar to the manufacturing apparatus shown in FIG. 1.

- Linear conductor used: Copper wire (diameter 40μmφ) - Yarn feeding method: bobbin rotation - Number of creels: 1000 - VI4 wire arrangement reed pitch: 100μn + (reed space ratio 50%) )・Liquid silicone species...manufactured by Toshiba Silicon Co., Ltd. (
JIS 3212)・Liquid silicone adhesion rate; 1st liquid silicone adhesion rate (in Figure 1 = 0.88 2nd liquid silicone adhesion rate (in Figure 1 = 0.10 ・Dryer temperature... 180 ”C Length: 1 m Winding and stacking speed of copper thin wire sheet: 1.0 m/min Size of annular structure to be manufactured Using the dimension symbols in Figure 3, R= 150 mm t = 100 mmD = 10
0 mm Annular structure weight 17.46 kg The annular structure manufactured under the above conditions was left in a dryer at a set temperature of 100°C for 48 hours with the flange bobbin for a winding device attached, and then removed from the flange bobbin.

1 Comparison ■ A circular structure was prepared as a comparative example under the same conditions as in the example except that the secondary liquid silicone deposition was omitted and the temperature setting of the dryer was changed to 80°C.

Next, the two obtained annular structures are shown in Fig. 3A and Fig. 3Be.
As shown in Figure 8, in order to know the dispersion state of the thin wires contained in the annular structure, lm is measured in the diameter direction ■◎ and the direction O■ perpendicular to the diameter direction of the structure before it is cut into parts, as shown in
When the number of fine copper wires contained within a plane of m x 1 mm was measured at 10 locations at equal intervals under magnification using a microscope, the results shown in Table 1 were obtained.

From Table 1, it was found that in the annular structure having anisotropic conductivity obtained by the manufacturing method according to the present invention, fine copper wires were extremely uniformly dispersed and arranged throughout the structure.

Therefore, it can be said that the anisotropically conductive sheet obtained from the annular structure obtained by the manufacturing method of the present invention has extremely uniform upper and lower electrical conductivity over the entire sheet surface and is useful.

〔Effect of the invention〕

Since the method for manufacturing an annular structure according to the present invention is configured as described above, the linear conductors are uniformly arranged in the annular structure produced using the method according to the present invention, and therefore, The arrangement spacing of the linear conductors in the anisotropic conductive sheet made from the annular structure can be made extremely uniform.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of an apparatus used to carry out the method for manufacturing an annular structure according to the present invention;
The figure is a cross-sectional view of an annular structure manufactured under different conditions according to the annular structure manufacturing method previously submitted by the same applicant as the present application, and FIG. FIG. 4 is a perspective view showing an enlarged view of the anisotropic conductive structure, and FIG. 5 shows the anisotropic conductive sheet. FIG. 5(A) is a perspective view thereof, FIG. 5(B) is a sectional view thereof, and FIG. 6 is a perspective view showing a cross section of an anisotropically conductive structure cut along a linear conductor. 7 is a sectional view of a bobbin used in the winding and laminating process section of the apparatus shown in FIG. 1, and FIG. 8 is a diagram showing the arrangement of linear conductors in an anisotropically conductive structure. FIG. 2 is a perspective view of an anisotropically conductive structure illustrating a method of measuring uniformity. 5... Insulating substance, 1o... Linear conductor, 20
...Annular structure, 30...Anisotropically conductive structure, 4
0... Anisotropic conductive sheet, 50... Yarn alignment process section, 51... Creel, 54... Reed, 60...
Insulating substance coating device, 61... Extruder, 62... T-die, 70...
-Drying process section, 80...Insulating material coating device, 81...Feed roll, 82...Insulating material adhesion roll, 83...Terriberry roll, 84...Bath, 90...
... Winding and laminating process section, 91... Winding bobbin. I- =0.5 G (A) (N, s -< Sn) Prostitute 6 Art 70

Claims (1)

[Claims] 1. The cross-sectional shape in any plane including its axis is substantially square or rectangular, and a plurality of linear conductors are connected to each other in a direction perpendicular to the plane through an insulating material. A method for manufacturing an annular structure in which the linear conductor is wound so as to be integrated into one body, the method comprising the following steps; (1) applying an insulating material in a viscous liquid state to at least one running linear conductor so that each linear conductor is coated with the insulating material; (2) heating at least one linear conductor coated with an insulating material in step (1); (3) at least one linear conductor heated in step (2); applying an adhesive substance in a viscous liquid state to each surface of the (5) Step (4) of forming an annular structure by winding it in a swing shape;
A heat treatment step performed during step (4) or after completion of step (4). 2. The method according to claim 1, wherein the adhesive substance applied in step (3) is the same material as the insulating substance applied in step (1). .