JP5335080B2 - Flexible flat cable with shield layer - Google Patents

Abstract

Provided is a flexible flat cable with a shield layer, which has both excellent electrical properties and an incombustible characteristic. A flat cable body (5) is made by having a pair, consisting of a foamed insulation film (2) with an adhesion layer on one-side thereof, and an incombustible resin film (3) with an adhesion layer on one-side thereof, adhered together, with both the adhesion layers mutually facing the inner side, and having multiple conductors (1) arranged in parallel at a prescribed interval between these films, and also providing terminal conductor-exposing sections (connecting terminal-sections) (t) by having the conductors at both ends exposed for a prescribed length. Furthermore, the flexible flat cable with shield layer (10) is made by having a shielded insulation film (6), which has an insulation film (6a) and a metal foil unified, has an incombustible layer (7) coated onto aforementioned insulation film (6a) surface, and which has an adhesion layer attached to aforementioned metal foil surface, adhered onto the outer surface of the foamed insulation film (2) surface of the flat cable body (5).

Description

  The present invention relates to a flexible flat cable with a shield layer, and more particularly, to a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy.

Flexible flat cables (hereinafter also referred to as flat cables) are widely used as printed circuit boards, internal wiring materials, or automobile internal wiring materials for electronic devices such as printers and scanners due to the space saving and simple connection of wiring materials. . Also, in video equipment such as liquid crystal TVs and plasma TVs, use has started as a high-speed signal transmission cable in which a flat cable is covered with a shielding material.
A conventional flat cable has a structure in which a plurality of conductors are arranged in parallel between two insulating films with both ends of the conductors exposed. A wiring method in which the flat cable and the insertion type connector are combined or a wiring method in which the flat cable and the pad of the board terminal are directly connected by soldering is widely used.
An example of a conventional flat cable will be described with reference to FIG.
Two insulating films (f, f) having a heat-sealable adhesive layer (not shown) on one side, with the adhesive layer surfaces facing each other, a plurality of flat conductors (1) are placed at a predetermined interval (pitch). ) And (p) are arranged in parallel, the conductors (1) at both ends are exposed for a predetermined length and are provided as connection terminal portions (terminal conductor exposed portions) (t), and the whole is heated and fused, preferably the connection terminal portions. A reinforcing tape (h) is attached to (t) to form a flat cable (50). This conventional flat cable is described in Patent Document 1 below.

JP 2001-43743 A

A flat cable used for the liquid crystal TV, plasma TV, etc. needs high-speed signal transmission performance. The characteristic impedance of the flat cable needs to be set to 100Ω (allowable range 100 ± 10Ω), which is the same as the impedance of the transmission / reception end of the high-speed digital signal. Thus, a flat cable having excellent electrical characteristics is demanded.
However, since a conventional flat cable uses a solid body as an insulating film, it is difficult to set the characteristic impedance of the flat cable to 100Ω, and there is a problem in that it is inferior in terms of electrical characteristics.
The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a shielded flexible flat cable having both excellent electrical characteristics and flame retardancy.

As a first aspect, the present invention is a two-piece set of one sheet of a foamed insulating film with an adhesive layer on one side and one sheet of a flame retardant resin film with an adhesive layer on one side, with both adhesive layer surfaces inside each other. In between, a plurality of conductors are arranged in parallel at a predetermined interval, the conductors of both ends are exposed for a predetermined length, and a connection terminal portion (terminal conductor exposed portion) is provided and bonded to form a flat cable body, A shield in which an insulating film and a metal foil are integrated on the outer surface of the foamed insulating film of the flat cable body, a flame retardant layer is coated (painted) on the surface of the insulating film, and an adhesive layer is attached to the surface of the metal foil Provided is a flexible flat cable with a shield layer, wherein an insulating film is bonded.
The flexible flat cable with a shield layer according to the first aspect uses a foamed insulator (not a solid body) with an adhesive layer on one side. Excellent electrical characteristics (for example, differential characteristic impedance, propagation delay time, insertion loss) can be obtained by the foamed insulator and the adhesive layer. Moreover, a flame retardance is acquired by the flame-retardant layer coated on the insulating film surface of the flame-retardant resin film with the adhesive layer on one side and the shield insulating film. Thus, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy is obtained.

As a second aspect, the present invention provides two foam insulating films with an adhesive layer on one side, both adhesive layer surfaces inside each other, and a plurality of conductors arranged in parallel at a predetermined interval between them. A conductor is exposed for a predetermined length, and a connection terminal portion (terminal conductor exposed portion) is provided and bonded to form a flat cable main body. Further, an insulating film is formed on both outer surfaces of the two foamed insulating films of the flat cable main body. With a shield layer, wherein a metal foil is integrated, a shield insulation film having a flame retardant coating (painted) on the surface of the insulation film and an adhesive layer on the surface of the metal foil is adhered to each other. Provide flexible flat cable.
In the flexible flat cable with a shield layer according to the second aspect, excellent electrical characteristics can be obtained by the foamed insulating film (not a solid body) having an adhesive layer on one side and the adhesive layer. Moreover, a flame retardance is acquired by the flame-resistant layer coated on the insulating film surface of each shield insulating film. Thus, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy similar to the flat cable of the first aspect is obtained.

As a third aspect, the present invention relates to a two-sheet set of one sheet of a foamed insulating film with an adhesive layer on one side and one sheet of a flame-retardant resin film with an adhesive layer on one side, with both adhesive layer surfaces inside each other. In between, a plurality of conductors are arranged in parallel at a predetermined interval, the conductors of both ends are exposed for a predetermined length, and a connection terminal portion (terminal conductor exposed portion) is provided and bonded to form a flat cable body, A metal foil and an insulating film are integrated on the outer surface of the foamed insulating film of the flat cable body, and a flame retardant resin film or a flame retardant layer coating insulation with an adhesive layer on one side at a predetermined position on the surface of the metal foil. Provided is a flexible flat cable with a shield layer, characterized in that a shield insulating film having a film adhered thereto and having an adhesive layer on the surface of the insulating film is adhered.
In the flexible flat cable with a shield layer according to the third aspect, excellent electrical characteristics can be obtained with a foamed insulating film (not a solid body) with an adhesive layer on one side and an adhesive layer. In addition, flame retardancy is obtained by the flame retardant resin film having an adhesive layer on one side and the flame retardant resin film or the flame retardant layer coating insulating film bonded to a predetermined position on the surface of the metal foil of the shield insulating film. . Thus, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy similar to the flat cables of the first and second aspects is obtained.
In addition, the said predetermined position is a position which left the part used as a ground plate (metal foil exposed part) of a terminal, for example in the metal foil surface of a shield insulation film.

As a fourth aspect, the present invention provides two foam insulating films with an adhesive layer on one side, both adhesive layer surfaces inside each other, and a plurality of conductors arranged in parallel at a predetermined interval between them. A conductor is exposed for a predetermined length, a connection terminal portion (terminal conductor exposed portion) is provided, and bonded to form a flat cable body. Further, metal foils are formed on both outer surfaces of the two foamed insulating films of the flat cable body. A shield in which an insulating film is integrated, a flame retardant resin film with an adhesive layer on one side or a flame retardant layer coating insulating film is bonded to a predetermined position on the surface of the metal foil, and an adhesive layer is attached to the surface of the insulating film Provided is a flexible flat cave with a shield layer, characterized in that insulating films are bonded to each other.
In the flexible flat cable with a shield layer according to the fourth aspect, excellent electrical characteristics can be obtained with a foamed insulating film (not a solid body) with an adhesive layer on one side and an adhesive layer. Moreover, a flame retardance is acquired by the flame-retardant resin film or flame-resistant layer coating insulation film adhere | attached on the predetermined position of the metal foil surface of each shield insulation film. Thus, similarly to the flat cables of the first, second, and third aspects, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy is obtained.
The predetermined position refers to, for example, a portion of the metal foil surface on the upper surface side (terminal conductor exposed surface side) used as a ground plate (metal foil exposed portion) on the entire surface, and the metal foil surface on the lower surface side is the terminal surface. This is a position where a portion used as a ground plate (metal foil exposed portion) remains.

As a fifth aspect, the present invention relates to a two-sheet set of one sheet of a foamed insulating film with an adhesive layer on one side and one sheet of a flame retardant resin film with an adhesive layer on one side, with both adhesive layer surfaces facing each other. In between, a plurality of conductors are arranged in parallel at a predetermined interval, the conductors of both ends are exposed for a predetermined length, and a connection terminal portion (terminal conductor exposed portion) is provided and bonded to form a flat cable body, A flame retardant resin film and a metal foil are integrated on the outer surface of the foamed insulating film of the flat cable body, and a shield flame retardant film having an adhesive layer on the surface of the metal foil is bonded. A flexible flat cable with a shield layer is provided.
In the flexible flat cable with a shield layer according to the fifth aspect, excellent electrical characteristics can be obtained with a foamed insulating film (not a solid body) having an adhesive layer on one side and an adhesive layer. Moreover, a flame retardance is acquired by the flame-retardant resin film with an adhesive layer on one side and the flame-retardant resin film of a shield flame-retardant film. Thus, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy similar to the flat cable of the first, second, third, and fourth aspects is obtained. Moreover, the man-hour of a flame-resistant layer coating can be reduced by integrating a flame-retardant resin film and metal foil beforehand.
The flame retardant resin film includes a non-flammable resin film.

As a sixth aspect, the present invention provides two foam insulating films with adhesive layers on one side, both adhesive layer surfaces inside each other, and a plurality of conductors arranged in parallel at a predetermined interval between them. A conductor is exposed for a predetermined length to provide a connection terminal portion (terminal conductor exposed portion) and bonded to form a flat cable main body. Further, flame retardant is provided on both outer surfaces of the two foamed insulating films of the flat cable main body. Provided is a flexible flat cable with a shield layer, wherein a resin film and a metal foil are integrated, and a shield flame retardant film having an adhesive layer on the surface of the metal foil is bonded.
In the flexible flat cable with a shield layer according to the sixth aspect, excellent electrical characteristics can be obtained with a foamed insulating film (not a solid body) having an adhesive layer on one side and an adhesive layer. Moreover, a flame retardance is acquired with each shield flame retardant film. Thus, a flexible flat cable with a shield layer having both excellent electrical characteristics and flame retardancy similar to the flat cable of the first, second, third, fourth, and fifth aspects is obtained.

As a seventh aspect of the present invention, the shield insulating film having an adhesive layer on the surface of the metal foil is coated with a conductive adhesive layer on one side of a metal foil having a thickness of 0.005 to 0.03 mm and insulated on the opposite side. It is a composite structure in which a film is laminated, or a composite structure in which a non-conductive adhesive layer is applied in a zebra shape on one side of a metal foil having a thickness of 0.005 to 0.03 mm and an insulating film is laminated on the opposite side. There is provided a flexible flat cable with a shield layer according to the first or second aspect.
In the flexible flat cable with a shield layer according to the seventh aspect, it is more preferable that the shield insulating film has the above-described configuration in terms of strengthening the adhesion with the outer surface of the foamed insulating film.
The reason for limiting the thickness of the metal foil to the above numerical range is that a metal foil having a thickness of less than 0.005 mm is difficult to manufacture, lacks superiority in terms of material procurement and price, and has a thickness of 0. This is because, when a metal foil exceeding 03 mm is used, the flexibility of the cable is extremely lost, so it is preferable to limit the value within this numerical range.

As an eighth aspect of the present invention, in the shield insulating film having an adhesive layer on the surface of the insulating film, a conductive adhesive layer or a non-conductive adhesive layer is applied on one side of the insulating film, and the thickness is 0.005 on the opposite side. Provided is a flexible flat cable with a shield layer according to the third or fourth aspect, wherein the flexible flat cable has a composite structure in which a metal foil of ˜0.03 mm is laminated.
In the flexible flat cable with a shield layer according to the eighth aspect, it is more preferable that the shield insulating film has the above-described configuration in terms of strengthening the adhesion with the outer surface of the foamed insulating film.
The reason for limiting the thickness of the metal foil to the above numerical range is the same as the reason for limiting the seventh aspect.

As a ninth aspect of the present invention, the shield flame retardant film having an adhesive layer on the surface of the metal foil is obtained by applying a conductive adhesive layer on one side of a metal foil having a thickness of 0.005 to 0.03 mm and It is a composite structure in which a flame-retardant resin film is laminated, or a non-conductive adhesive layer is applied to one side of a metal foil having a thickness of 0.005 to 0.03 mm in a zebra shape, and the flame-retardant resin is applied to the opposite side A flexible flat cable with a shield layer according to the fifth or sixth aspect, wherein the flexible flat cable has a composite structure in which films are laminated.
In the flexible flat cable with a shield layer according to the ninth aspect, it is more preferable that the configuration of the shield insulating film is the above configuration in terms of improving flame retardancy.
The reason for limiting the thickness of the metal foil to the above numerical range is the same as the reason for limiting the seventh aspect.

As a tenth aspect, in the present invention, the foamed insulating film with an adhesive layer on one side has a thickness of 0.15 to 0.25 mm, a relative dielectric constant of 2.0 to 3.0, and a dielectric loss tangent of 0.003 to 0.00. A 010 foam insulating film is coated with an adhesive layer having a thickness of 0.020 to 0.050 mm and a relative dielectric constant of 2.5 to 4.5 and a dielectric loss tangent of 0.010 to 0.030. A flexible flat cable with a shield layer according to any one of the first to ninth aspects is provided.
In the flexible flat cable with a shield layer according to the tenth aspect, the thickness, relative dielectric constant, and dielectric loss tangent of the foamed insulating film (not solid) with the adhesive layer on one side and the adhesive layer are limited to the above numerical range. As a result, more excellent electrical characteristics can be obtained.
In addition, the said numerical range was obtained by making many trial manufactures (refer to the chart 7, Examples 1-6, another Example, and a comparative example).

As an eleventh aspect of the present invention, the flame retardant layer comprises an organic phosphorus flame retardant with respect to 100 parts by weight of a polyester base resin having a glass transition point (Tg) of 30 ° C. or less and a breaking elongation of 200% or more. A flexible flat cable with a shield layer according to any one of the first to fourth, seventh, eighth, and tenth aspects, characterized by being a flame retardant layer containing 200 to 500 parts by weight of .
From the viewpoint of ensuring the safety of equipment, flame retardant treatment for flat cables is mandatory. In a conventional flat cable provided with flame retardancy, for example, a flame retardant such as a chlorine compound or a bromine compound (hereinafter abbreviated as a halogen compound) is applied to the heat-fusible adhesive layer of the insulating film constituting the flat cable. It was made to have flame retardancy by adding. In addition, as a standard regarding the flame retardance of an electric wire or a cable, there exists UL94 VW-1 flame resistance test standard (henceforth VW-1 test), for example.
However, there has been a problem in terms of non-halogenation that has been required in recent years.
On the other hand, in the flexible flat cable with a shield layer according to the eleventh aspect, it is preferable that the flame retardant layer has the above configuration in order to achieve non-halogenation and to maintain good flame retardancy and mechanical properties.
The reason why the glass transition point (Tg) of the polyester base resin is limited to 30 ° C. or less and the breaking elongation is limited to 200% or more is that the durability of the flame retardant layer is deteriorated under the actual use temperature environment outside this range ( This is because the adhesion with the insulating film surface is reduced).
The reason why the content of the organic phosphorus flame retardant is limited to 200 to 500 parts by weight is as follows.
(1) Without flame retardant layer coating: VW-1 test failure (2) With flame retardant 100 parts by weight: Flame retardant is not sufficient, VW-1 test failure (3) Flame retardant 200-500 In the case of parts by weight: The flame retardancy is sufficient, passes the VW-1 test, and the flexibility and adhesion are good and the flame retardant layer does not peel off. (4) In the case of 600 parts by weight of the flame retardant: Flexibility and adhesion Is bad, peeling occurs and NG
In addition, the adhesive force can be further improved by coating the flame retardant layer after applying a primer treatment to the insulating film surface in advance.

As a twelfth aspect, the present invention provides the flame retardant layer,
(A) whether the insulating film surface of the shield insulating film is coated in advance;
(B) After the shield insulation film is adhered to the flat cable body, the insulation film surface of the shield insulation film is coated,
(C) After the shield insulation film is adhered to the flat cable body, the insulation film is adhered to a predetermined position on the metal foil surface of the shield insulation film and then coated on the surface of the insulation film,
A flexible flat cable with a shield layer according to any one of the first to fourth, seventh, eighth, tenth, or eleventh aspects is provided.
In the flexible flat cable with a shield layer according to the twelfth aspect, the flame retardant layer can be suitably coated on the insulating film surface or the insulating film of the shield insulating film by the above method.

As a thirteenth aspect of the present invention, the flexible flat cable with a shield layer according to any one of the first to twelfth aspects is manufactured by several sets at the same time and then slit (collectively cut). A flexible flat cable with a shield layer is provided.
In the flexible flat cable with a shield layer according to the thirteenth aspect, after several sets are manufactured at the same time, slitting and separating into individual flat cables having a specified number of conductor cores can dramatically improve mass productivity. I can do it. In addition, the flexible flat cable with a shield layer of this aspect uses a flame-retardant resin film with an adhesive layer on one side and a shield insulation film with a flame-retardant layer coated on the insulation film side. Even in this respect, it is inferior to the conventional structure in which the entire surface is wrapped with a shield layer.

As a fourteenth aspect, the present invention provides the flexible flat cable with a shield layer according to any one of the first to thirteenth aspects, wherein one foamed insulating film itself is used as a reinforcing plate instead of separately attaching the reinforcing plate. A flexible flat cable with a shield layer is provided.
In the flexible flat cable with a shield layer according to the fourteenth aspect, one foamed insulating film itself can be used as a reinforcing plate, so that the conventionally required reinforcing plate is not required and the cost is reduced.

According to the flexible flat cable with a shield layer of the present invention, excellent electrical characteristics can be obtained by the foamed insulating film (not solid) and the adhesive layer.
Also, (1) a flame retardant layer coated on the insulating film surface of the flame retardant resin film and the shield insulating film, or (2) a flame retardant layer coated on the insulating film surface of each shield insulating film, or (3 ) A flame retardant resin film or a flame retardant layer coating insulating film adhered to a predetermined position on the metal foil surface of the shield insulating film, or (4) a flame retardant bonded to a predetermined position on the metal foil surface of each shield insulating film. A flame retardant resin film or a flame retardant layer coating insulating film, or (5) a flame retardant resin film of a flame retardant resin film and a shield flame retardant film, and (6) a flame retardant resin film of each shield flame retardant film. High flame retardancy can be obtained, so a shielded layer with excellent electrical properties and flame retardancy Carboxymethyl became a flat cable.
As a result, a high-speed digital signal exceeding 400 Mbps can be transmitted over a long distance of 500 mm or more by using a foamed insulating film and an adhesive layer excellent in electrical characteristics surrounding the conductor group while ensuring high flame retardancy.
Moreover, in the flexible flat cable with a shield layer of this invention, the flame retardance is not calculated | required by the contact bonding layer of an insulating film. Therefore, it becomes unnecessary to add a flame retardant filler to the adhesive layer for the flame retardant treatment of the adhesive layer. As a result, the flame retardant resin film and the foamed insulating film adhesive layer constituting the flexible flat cable with shield layer of the present invention can be freely selected to obtain the desired performance (electrical characteristics, adhesive strength, etc.). I can do it now.
Further, since it is no longer necessary to use a flame retardant such as a halogen compound in the adhesive layer, it can be easily non-halogenated.
In addition, a flame-retardant flat cable that complies with UL94 VW-1 flame resistance test standards can be obtained.
Therefore, the present invention has an extremely large effect contributing to the industry.

FIG. 1 is a schematic view showing Example 1 of a flexible flat cable with a shield layer according to the present invention. FIG. 1 (a) is a perspective view, and FIG. 1 (b) is a cross-sectional view taken along line bb in FIG. FIG. FIG. 2 is a schematic view showing Example 2 of the flexible flat cable with a shield layer of the present invention. FIG. 2 (a) is a perspective view, and FIG. 2 (b) is a cross-sectional view taken along the line bb in FIG. FIG. FIG. 3 is a chart showing the characteristic impedance of the flexible flat cable with a shield layer according to the first embodiment of the present invention. FIG. 4 is a chart showing insertion loss characteristics of the flexible flat cable with a shield layer according to the first embodiment of the present invention. FIG. 5 is a chart showing an eye pattern (Differential Eye-Pattern), where FIG. 5A is an input waveform, and FIG. 5B is a measurement result of a flexible flat cable with a shield layer of Example 1 of the present invention. It is. FIG. 6 is a perspective view showing an example of a conventional flexible flat cable. FIG. 7 is a table summarizing the physical properties of Examples 1 to 6, other examples and comparative examples. FIG. 8 is a schematic view showing Example 3 of the flexible flat cable with a shield layer of the present invention, where FIG. 8 (a) is a perspective view, and FIG. 8 (b) is a cross-sectional view taken along the line bb of FIG. FIG. FIG. 9 is a schematic view showing Example 4 of the flexible flat cable with a shield layer of the present invention, where FIG. 9 (a) is a perspective view, and FIG. 9 (b) is a cross-sectional view taken along line bb of FIG. FIG.

  Hereinafter, the contents of the present invention will be described in more detail with reference to examples (embodiments) shown in the drawings. Note that the present invention is not limited thereby.

Example 1
Example 1 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view taken along line bb in FIG. 1A.
A foamed insulating film (2f) with a heat-fusible polyester-based adhesive layer (2s) (for example, a foamed PET (polyethylene terephthalate) film with a polyester-based adhesive layer) is used as the foamed insulating film (2) with an adhesive layer on one side. . The thickness is 0.223 mm. For the heat-fusible polyester adhesive layer (2s), a material having a thickness of 0.035 mm, a relative dielectric constant of 3.6, and a dielectric loss tangent of 0.014 was used. A foamed insulating film (2f) having a thickness of 0.188 mm, a relative dielectric constant of 2.8, and a dielectric loss tangent of 0.005 was used.
As the flame-retardant resin film with an adhesive layer (3) on one side, a flame-retardant resin film (3f) with a heat-fusible polyester-based adhesive layer (3s) (for example, a polyimide-coated PET film with a polyester-based adhesive layer) is used. . The thickness is 0.057 mm. As the foamed insulating film ( 3 f), a film having a thickness of 0.188 mm, a relative dielectric constant of 2.8, and a dielectric loss tangent of 0.005 was used.
As the plurality of conductors (1), two or more flat conductors (for example, 51 bare soft copper flat conductors) (only three are shown in the figure) having a conductor size of 0.035 mm in thickness and 0.3 mm in width are used. The plurality of conductors (1) are arranged in parallel so that the distance between the conductor centers is 0.5 mm to form a conductor group.
The conductor group is composed of a foamed insulating film (2) with an adhesive layer on one side, a flame retardant resin film (3) with an adhesive layer on one side, and both adhesive layers (2s) and (3s) on the inside. Hold in both directions from both sides. Moreover, the connection terminal part (terminal conductor exposed part) (t) is provided by exposing the conductors of both terminals for a predetermined length.
Then, it laminated and set it as the flat cable main body (5).
Subsequently, a shield insulation film (6) is affixed on the outer surface of the foam insulation film (2f) of the flat cable body (5).
As a shield insulating film (6), a heat-fusible polyester adhesive layer (6s) is applied in a zebra shape on one side of an aluminum foil (6k) to be a shield layer, and a PET film (6f) is laminated on the opposite side. Use the product.
Further, a flame retardant layer (7) is provided on the surface of the PET film (6f) by coating a flame retardant blended resin obtained by adding an organic phosphorus flame retardant to a polyester base resin. As said flame retardant compounding resin, the thing which contained 200 weight part of organophosphorus flame retardant with respect to 100 weight part of polyester-type base resins was used.
Thus, a flexible flat cable (10) with a shield layer having a shield layer provided on one side was produced.
The conductor (1) is more preferably made of annealed copper and subjected to surface treatment only at the terminal exposed portion by metal plating. A round conductor can also be used.
The flame retardant layer (7) may be coated in advance on the surface of the PET film (6f) of the shield insulating film (6). In this case, it can be handled as one flame retardant layer coat shield insulating film (8). If this flame retardant layer coated shield insulation film (8) is attached to the outer surface of the foam insulation film (2f) of the flat cable body (5) by the polyester adhesive layer (6s), the shield layer is formed on one side similar to the above. The provided flexible flat cable (10) with a shield layer can be manufactured.
As a specific example of the flame retardant layer coated shield insulating film (8), AL-PET obtained by laminating a 0.009 mm PET film (6f) on a 0.007 mm aluminum foil (6k) can be used.
In addition, after manufacturing several sets of said flexible flat cables (10) with a shield layer, they may be slit and made into individual flat cables.

-Example 2-
Example 2 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG.
As in Example 1 above, two or more flat conductors (1) having conductor dimensions of thickness 0.035 mm and width 0.3 mm (for example, 51 bare soft copper flat conductors) (only three are shown in the figure) A conductor group is formed by arranging them in parallel so that the distance between the conductor centers is 0.5 mm. This conductor group is formed from two sides in the thickness direction using a foamed insulating film (2f) (for example, a foamed PET film with a polyester adhesive layer) having the same thickness of 0.223 mm and having a polyester adhesive layer (2s). Both adhesive layers (2s) and (2s) are sandwiched inside. Moreover, the connection terminal part (terminal conductor exposed part) (t) is provided by exposing the conductors of both terminals for a predetermined length. Then, it laminated and set it as the flat cable main body (15).
Next, the flame retardant layer coated shield insulating film (8) shown in Example 1 is applied to the both outer surfaces of the both foamed insulating films (2f) and (2f) of the flat cable body (15). ) On the inside.
As described above, a flexible flat cable with shield layer (20) having shield layers on both sides was produced.
Here, as the polyester-based adhesive layer (2s), the same material as in Example 1 having a thickness of 0.035 mm, a relative dielectric constant of 3.6, and a dielectric loss tangent of 0.014 was used. On the other hand, as the foamed insulating films (2f) and (2f), those having a thickness of 0.188 mm, a relative dielectric constant of 2.3, and a dielectric loss tangent of 0.005 were used.
In the case of providing a ground plate to the flexible flat cable terminal shielded layer obtained in Examples 1 and 2, a ground plate of the shield and the cable terminal is divided, Ru is contacted by the rerouting.

-Example 3-
Example 3 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG.
As a foam insulation film (2) with an adhesive layer on one side, a foam insulation film (2f) with a heat-fusible polyester adhesive layer (2s) having a thickness of 0.223 mm (for example, foamed PET (polyethylene with polyester adhesive layer) Terephthalate) film). The same material as in Example 1 was used for the heat-fusible polyester adhesive layer (2s). Moreover, the same thing as the said Example 1 was used also for the said foaming insulation film (2f).
Flame retardant resin film (3f) with a heat-fusible polyester adhesive layer (3s) having a thickness of 0.057 mm (for example, with a polyester adhesive layer) as a flame retardant resin film (3) with an adhesive layer on one side Polyimide-coated PET film ) is used.
As a plurality of conductors (1), two or more rectangular conductors (1) having conductor dimensions of 0.035 mm thickness and 0.3 mm width (for example, 51 bare soft copper rectangular conductors) (only three are shown in the figure) Is used. The plurality of conductors (1) are arranged in parallel so that the distance between the conductor centers is 0.5 mm to form a conductor group.
The conductor group is composed of a foamed insulating film (2) with an adhesive layer on one side, a flame retardant resin film (3) with an adhesive layer on one side, and both adhesive layers (2s) and (3s) on the inside. Hold in both directions from both sides. Moreover, the connection terminal part (terminal conductor exposed part) (t) is provided by exposing the conductors of both terminals for a predetermined length.
Then, it laminated and set it as the flat cable main body (5).
Next, a shield insulation film (6 ′) is attached to the outer surface of the foam insulation film (2f) of the flat cable body (5).
As the shield insulating film (6 ′), a PET film (6f) coated with a heat-sealable polyester adhesive layer (6s) on one side and laminated with an aluminum foil (6k) on the opposite side is used. Specifically, an AL-PET obtained by laminating a 0.009 mm PET film (6f) on a 0.007 mm aluminum foil (6k) and coating the surface of the PET film (6f) with a polyester adhesive layer (6s). used.
Furthermore, a flame retardant blended resin is coated on the surface of the insulating film (9f) at a predetermined position on the surface of the aluminum foil (6k) (a surface other than a portion used as a terminal ground plate (metal foil exposed portion) (u)). The flame retardant layer coating insulating film (9) provided with the flame retardant layer (7) is adhered.
As said flame retardant compounding resin, the thing containing 200 weight part of organophosphorus flame retardants with respect to 100 weight part of polyester-type base resins was used.
As described above, a flexible flat cable (30) with a shield layer having a shield layer provided on one side was produced.

Example 4
Example 4 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG.
As in Example 1 above, two or more flat conductors (1) having conductor dimensions of thickness 0.035 mm and width 0.3 mm (for example, 51 bare soft copper flat conductors) (only three are shown in the figure) A conductor group is formed by arranging them in parallel so that the distance between the conductor centers is 0.5 mm. This conductor group is formed from two sides in the thickness direction using a foamed insulating film (2f) (for example, a foamed PET film with a polyester adhesive layer) having the same thickness of 0.223 mm and having a polyester adhesive layer (2s). Both adhesive layers (2s) and (2s) are sandwiched between them. Moreover, the connection terminal part (terminal conductor exposed part) (t) is provided by exposing the conductors of both terminals for a predetermined length. Then, it laminated and set it as the flat cable main body (15). Here, the same thing as the said Example 2 was used for the said foaming insulation film (2f).
Subsequently, the same thing as the said Example 3 is affixed on both the outer surfaces of the foam insulation film (2f) of the said flat cable main body (15) as a shield insulation film (6 '), and also the upper side aluminum foil (6k) The same surface is bonded with the same flame retardant layer coating insulating film (9) as in Example 3 above, and the surface of the aluminum foil (6k) on the lower surface side is at a predetermined position (terminal ground plate (metal foil exposed portion)). The same flame retardant layer coating insulating film (9) as in Example 3 was adhered to the surface other than the portion used as (u). Here, the same thing as the said Example 3 was used as a flame retardant compounding resin of a flame retardant layer coating insulation film (9).
As described above, a flexible flat cable with a shield layer (40) having shield layers on both sides was produced.
In addition, you may affix a flame-resistant layer coat | cover shield insulating film directly on the outer surface of a foamed insulating film similarly to the said Examples 1 and 2 to the shield insulating film of the side which is not used as a ground board.
Since the flexible flat cable with a shield layer obtained in Examples 3 and 4 has a structure in which the aluminum foil surface of the shield insulation film of the terminal is exposed, the terminal can be used as a ground plate without any reconnection. .
Further, in the flexible flat cable with a shield layer obtained in Examples 3 and 4, the shield and the ground plate are integrated, and the contact resistance at this portion can be ignored. , Reduction of EMS).

-Example 5
Example 5 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG. In Example 5, the shield insulation film (6) in FIG. 1 is replaced with a shield flame retardant film, and there is no flame retardant layer (7).
First, a flat cable body (5) having the same structure as in Example 1 was manufactured.
Next, on the outer surface of the foamed insulating film (2f) of the flat cable body (5), as a shield flame retardant film (corresponding to (6) in FIG. 1), an aluminum foil having a thickness of 0.007 mm serving as a shield layer ( 6k) is coated with a heat-bondable polyester adhesive layer (6s) in a zebra shape with a thickness of 0.010 mm on one side, and PPS (polyphenylene sulfite with a thickness of 0.009 mm as a flame retardant resin film on the opposite side. A laminate of a resin) film (corresponding to (6f) in FIG. 1) was attached.
Thus, a flexible flat cable with a shield layer having a shield layer provided on one side was produced.
As the flame retardant resin film, a polyimide film or a fluorine resin film can be used instead of the PPS film.

-Example 6
Example 6 of the flexible flat cable with a shield layer of the present invention will be described with reference to FIG. In Example 6, the shield insulation film (6) in FIG. 2 is replaced with a shield flame retardant film, and there is no flame retardant layer (7).
First, a flat cable body (5) having the same structure as that of Example 2 was manufactured.
Next, on both outer surfaces of the foamed insulating film (2f) of the flat cable body (5), an aluminum foil having a thickness of 0.007 mm serving as a shield layer as a shield flame retardant film (corresponding to (6) in FIG. 2). A heat-fusible polyester adhesive layer (6s) is applied in a zebra shape on one side of (6k) to a thickness of 0.010 mm, and a PPS film having a thickness of 0.009 mm on the opposite side (corresponding part of FIG. 2 (6f)) ) Was pasted.
As described above, a flexible flat cable with a shield layer having shield layers provided on both sides was manufactured.
In addition, when providing a ground plate in the terminal of the flexible flat cable with a shield layer obtained in the said Example 5 and 6, the ground board of a shield and a cable terminal is divided | segmented and connected similarly to the said Example 1 and 2. Contact by replacement.

-About trial production-
In the tenth aspect, the foam insulation film of the foam insulation film with the adhesive layer and the thickness range of the adhesive layer, the relative dielectric constant and the dielectric loss tangent are limited, but this limitation is limited to many prototypes (Chart 7, Examples 1 to 6 and other examples and comparative examples). In addition, about the other Example and the comparative example, the structure except the combination of the numerical value range of the thickness of a foaming insulating film and an adhesive layer, a dielectric constant, and a dielectric loss tangent was made the same as the said Example 2.

-Electrical characteristics test-
With respect to the flexible flat cable with a shield layer of Example 1, the sample lot was set to 3, and the characteristic impedance, the insertion loss characteristic, the propagation delay time, and the eye pattern were tested.
In these tests, a TDR (Time Domain Reflect meter) measuring instrument (manufactured by Nippon Tektronix: TDS8000, sampling head 80E04) was used, and the connection with the flexible flat cable with the shield layer was performed through a dedicated jig.
FIG. 3 shows the test results of characteristic impedance.
As is clear from the chart of FIG. 3, the flexible flat cable with a shield layer of the present invention can secure a differential characteristic impedance of 100 ± 10Ω.
FIG. 4 shows the insertion loss characteristic test results.
As is clear from the chart of FIG. 4, the flexible flat cable with a shield layer of the present invention can secure an insertion loss of 19 dB / m (at 5.1 GHz).
FIG. 5 shows the eye pattern test results.
As is apparent from the chart of FIG. 5, the eye pattern has a large aperture ratio at a transmission rate of 2 Gbps. That is, the quality of the transmission signal was good. Although not shown, the same applies to 3 Gbps.
Moreover, it tested similarly about the flexible flat cable with a shield layer of Examples 2-6, and the same favorable electrical property as the flat cable of Example 1 was obtained.

-Combustion test-
About the flexible flat cable with a shield layer obtained by the said Example 1, 2, the combustion test was done according to UL94 VW-1 (test product hold | maintained to the perpendicular state) flame resistance test standard.
As a result, the flexible flat cable with a shield layer of Examples 1 and 2 cleared the test standard.
Moreover, it tested similarly about the flexible flat cable with a shield layer of Examples 3-6, and was able to clear the test standard similarly to the flexible flat cable with a shield layer of Examples 1,2.
An outline of the test standard of the UL94 VW-1 flame resistance test will be described.
• When the standard test flame contact for 15 seconds is performed 5 times on the test piece held in the vertical state, the following shall not occur at any time.
(A) Flame propagation to the entire test product,
(B) More than 25% burnout or carbonization on the indicator flag attached to the test specimen at any point of the propagation of flames to nearby flammables and 5th flame contact (occurrence of soot that can be removed with cloth or fingers and If brown scorch is not considered carbonized), the wire, cable or cord is considered to have a flame spread throughout the specimen. When the absorbent cotton ignited on the burner, wedge or test surface is ignited by a flammable piece, red hot piece or flammable drop of the test product at any point in time (the burning of absorbent cotton that does not lead to the occurrence of flame is ignition) Not to be considered) and when the test piece continues to burn for more than 60 seconds during the flame contact period of the gas flame or after the flame contact is over, the wire, cable or cord propagates to nearby combustibles. It is considered to be. (failure)

  The flexible flat cable with a shield layer of the present invention has excellent electrical characteristics and flame retardancy, and can be used as a high-speed signal transmission cable.

1 Conductor (flat rectangular conductor)
2 Foam insulation film with adhesive layer (foamed PET film with adhesive layer)
2f Foam insulation film (foamed PET film)
2s adhesive layer (polyester adhesive layer)
3 Flame-retardant resin film with adhesive layer (Polyimide-coated PET film with adhesive layer)
3f Flame-retardant resin film (polyimide coated PET film)
3s adhesive layer (polyester adhesive layer)
5 Flat cable body 6 Shield insulation film (shield insulation film with metal foil surface adhesive layer)
6 'Shield insulation film (shield insulation film with adhesive film surface adhesive layer)
6f Insulating film (PET film)
6k shield layer (metal foil, aluminum foil)
6s adhesive layer (polyester adhesive layer)
7 Flame retardant layer (flame retardant compound resin)
8 Flame retardant layer coated shield insulating film 9 Flame retardant layer coated insulating film 9f Insulating film 10 Flexible flat cable with shield layer (Flexible flat cable with single-sided shield layer)
15 Flat cable body 20 Flexible flat cable with shield layer (Flexible flat cable with double-sided shield layer)
30 Flexible flat cable with shield layer (Flexible flat cable with single-sided shield layer)
40 Flexible flat cable with shield layer (Flexible flat cable with double-sided shield layer)
t Connection terminal part (terminal conductor exposed part)
u Ground plate (exposed metal foil)

Claims (13)

  Two sheets of a foam insulation film with an adhesive layer on one side and a flame retardant resin film with an adhesive layer on one side, with both adhesive layers facing each other, with multiple conductors in between Arranged in parallel at a predetermined interval, exposed the conductor of both ends for a predetermined length, provided a connection terminal portion, bonded to form a flat cable body, and further, an insulating film on the outer surface of the foamed insulating film of the flat cable body A flexible flat cable with a shield layer, wherein a shield insulation film in which a flame retardant layer is coated on the insulating film surface and an adhesive layer is attached to the surface of the metal foil is bonded. Two sheets of a foam insulation film with an adhesive layer on one side and a flame retardant resin film with an adhesive layer on one side, with both adhesive layers facing each other, with multiple conductors in between Arranged in parallel at a predetermined interval, exposed the conductor of both ends for a predetermined length, provided a connection terminal portion, and bonded to form a flat cable body, and further, a metal foil on the outer surface of the foamed insulating film of the flat cable body And an insulating film are integrated, a flame retardant resin film with an adhesive layer on one side or a flame retardant coating insulating film is adhered to a predetermined position on the surface of the metal foil, and an adhesive layer is attached to the surface of the insulating film A flexible flat cable with a shield layer, wherein a shield insulating film is bonded. Two terminals of foam insulation film with adhesive layer on one side, both adhesive layer surfaces inside each other, a plurality of conductors are arranged in parallel at a predetermined interval between them, and the conductors of both ends are exposed for a predetermined length to connect terminals A flat cable body, and a metal foil and an insulating film are integrated on both outer surfaces of the two foamed insulating films of the flat cable body, and a predetermined position on the surface of the metal foil is provided. Has a shield layer characterized in that a flame-retardant resin film with an adhesive layer on one side or a flame-retardant layer-coated insulating film is bonded, and a shield insulating film with an adhesive layer is bonded to the surface of the insulating film. Flexible flat cable. Two sheets of a foam insulation film with an adhesive layer on one side and a flame retardant resin film with an adhesive layer on one side, with both adhesive layers facing each other, with multiple conductors in between Arranged in parallel at a predetermined interval, exposed the conductors of both terminals for a predetermined length, provided a connection terminal part, and bonded to form a flat cable body, and further on the outer surface of the foam insulation film of the flat cable body, flame retardant A flexible flat cable with a shield layer, wherein a heat-resistant resin film and a metal foil are integrated, and a shield flame retardant film having an adhesive layer on the surface of the metal foil is bonded . The shield insulating film with an adhesive layer on the surface of the metal foil has a composite structure in which a conductive adhesive layer is applied to one side of a metal foil having a thickness of 0.005 to 0.03 mm and an insulating film is laminated on the opposite side. Or a composite structure in which a non-conductive adhesive layer is applied in a zebra shape on one side of a metal foil having a thickness of 0.005 to 0.03 mm and an insulating film is laminated on the opposite side. The flexible flat cable with a shield layer according to 1 . The shield insulating film with an adhesive layer on the insulating film surface is coated with a conductive adhesive layer or a non-conductive adhesive layer on one side of the insulating film, and a metal foil having a thickness of 0.005 to 0.03 mm is applied to the opposite side. 4. The flexible flat cable with a shield layer according to claim 2, wherein the flexible flat cable has a laminated composite structure . The shielded flame retardant film having an adhesive layer on the surface of the metal foil was obtained by applying a conductive adhesive layer to one side of a metal foil having a thickness of 0.005 to 0.03 mm and laminating a flame retardant resin film on the opposite side. It is a composite structure or a composite structure in which a non-conductive adhesive layer is applied in a zebra shape on one side of a metal foil having a thickness of 0.005 to 0.03 mm, and a flame-retardant resin film is laminated on the opposite side The flexible flat cable with a shield layer according to claim 4 . The foamed insulating film with an adhesive layer on one side has a thickness of 0.15 to 0.25 mm, a dielectric constant of 2.0 to 3.0, and a dielectric loss tangent of 0.003 to 0.010. An adhesive layer having a relative dielectric constant of 2.5 to 4.5 and a dielectric loss tangent of 0.010 to 0.030 is coated at 0.020 to 0.050 mm. The flexible flat cable with a shield layer in any one of Claim 3, Claim 5, or Claim 6 . The foamed insulating film with an adhesive layer on one side has a thickness of 0.15 to 0.25 mm, a dielectric constant of 2.0 to 3.0, and a dielectric loss tangent of 0.003 to 0.010. An adhesive layer having a dielectric constant of 0.010 to 0.030 and a dielectric constant of 2.5 to 4.5 and a relative dielectric constant of 2.5 to 4.5 is coated. The flexible flat cable with a shield layer as described . The flame retardant layer contains 200 to 500 parts by weight of an organic phosphorus flame retardant with respect to 100 parts by weight of a polyester base resin having a glass transition point (Tg) of 30 ° C. or less and a breaking elongation of 200% or more. The flexible flat cable with a shield layer according to claim 1, wherein the flexible flat cable is a flame retardant layer . The flame retardant layer is
(A) whether the insulating film surface of the shield insulating film is coated in advance;
(B) After the shield insulation film is adhered to the flat cable body, the insulation film surface of the shield insulation film is coated,
(C) after adhering the shield insulating film to the flat cable main body, adhering the insulating film to a predetermined position on the surface of the metal foil of the shield insulating film, and then being coated on the surface of the insulating film;
The flexible flat cable with a shield layer according to claim 1, wherein the flexible flat cable is a shield layer according to any one of claims 1, 2, 3, 5, 6, 8, or 10 . The flexible flat cable with a shield layer according to any one of claims 1 to 11, wherein several sets of the flexible flat cable with a shield layer are manufactured simultaneously and then cut . The flexible flat cable with a shield layer according to any one of claims 1 to 12, wherein one foamed insulating film itself is used as a reinforcement plate instead of separately attaching the reinforcement plate. Flexible flat cable .

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