JP2002231062A - Shielded flat cable and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shielded flat cable that can secure bending resistance without requiring a complicated process, and its manufacturing method. SOLUTION: The flat cable body 1 is constructed by embedding a plurality of conductor wires 12 between the insulating layers 11, 13. A shielded flat cable is made by covering this flat cable body 1 by a shielding tape 2. The shielding tape 2 is constructed by forming a metal vapor deposition layer 22 on a resin film 21, and an insulating bonding layer 3 is applied thinly on the whole face of this metal deposition layer 22, and further a conductive bonding layer 4 is printed and formed in an island pattern on top of it. By crimping the shielded tape 2 on the flat cable body 1, the conductive bonding layer 4 is mixed with the insulating bonding layer 3 and conducts with the metal deposition layer 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to various information devices,
The present invention relates to a shielded flat cable used in communication equipment and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, flat cables have been used as signal transmission cables for various information devices and communication devices. This type of flat cable requires shielding against electromagnetic waves, and various shielded flat cables have been developed and used. For example, a flat cable main body is made by laminating an insulating film with a plurality of conductor wires interposed therebetween, and by covering the periphery with a shield tape, a shielded flat cable is obtained.

A method of using a conductive adhesive containing a metal filler as a shield layer of a shield tape is, for example, as follows.
It is disclosed in JP-A-6-283053. According to this method, by forming a hole in the grounding conductor wire portion of the flat cable main body, the grounding conductor wire can be electrically connected to the shield layer by thermocompression bonding the shield tape to the flat cable main body. .

[0004]

However, if the conductive adhesive layer is applied to the entire surface of the shield tape, the cost of processing the shield flat cable increases because the conductive adhesive layer is expensive. In order to reduce the cost, it is conceivable to use a shield tape in which a metal deposition layer is formed on the entire surface of a shield base material, and print and apply a conductive adhesive layer on the surface of the shield tape, for example, as a plurality of stripe patterns. However, when such intermittent coating is performed, the metal deposition layer may be broken at the bent portion of the flat cable. To prevent this, the conductive adhesive layer and the insulating adhesive layer may be printed and applied alternately in a stripe pattern, but this complicates the processing process and equipment,
This results in higher costs and lower productivity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a shielded flat cable which does not require a complicated process and can ensure bending resistance, and a method of manufacturing the same. And

[0006]

According to the present invention, there is provided a shielded flat cable in which a flat cable body in which a plurality of conductor wires are disposed inside an insulating layer is covered with a shield tape. A metal deposition layer is formed as a shield layer on the surface of the material, an insulating adhesive layer is applied over the entire surface of the metal deposition layer, and a conductive adhesive layer is printed in a predetermined pattern on the surface of the insulating adhesive layer,
The conductive adhesive layer is mixed with the insulating adhesive layer and thermocompression-bonded to the flat cable body so as to be connected to the metal deposition layer.

The present invention also provides a method of manufacturing a shielded flat cable by covering a flat cable body having a plurality of conductor wires disposed inside an insulating layer with a shield tape, wherein the shield layer is formed on the surface of the tape base material. An insulating adhesive layer is applied to the entire surface of the metal evaporated layer of the shield tape on which the metal evaporated layer is formed, and a conductive adhesive layer is printed in a predetermined pattern on the surface of the insulating adhesive layer, and the conductive adhesive layer is The shield tape is thermocompression-bonded to the flat cable body so as to be mixed with the insulating adhesive layer and connected to the metal deposition layer.

According to the present invention, an insulating adhesive layer is applied to the entire surface of the shield tape on which the metal vapor-deposited layer is formed, and the conductive adhesive layer is printed thereon as a predetermined pattern, preferably an array of island patterns. Thereby, cracking of the metal deposition layer due to bending of the shielded flat cable is prevented. If the insulating adhesive layer is formed to be thin to some extent, the conductive adhesive layer is mixed with the insulating adhesive layer in the thermocompression bonding step, and electrical conduction between the conductive adhesive layer and the metal deposition layer can be obtained. Because only the conductive adhesive layer is printed and applied in a predetermined pattern,
The processing cost of the shielded flat cable is also low.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view including a cut surface of a shielded flat cable according to an embodiment of the present invention in a direction orthogonal to a conductor wire. The flat cable body 1
The plurality of conductor wires 12 arranged in parallel are connected to the insulating layers 11 and 1.
3 and buried between them. A shield tape 2 is coated around the flat cable main body 1. A hole 14 is formed in the insulating layer 13 in a part of the conductor wire 12 embedded in the flat cable main body 1 on the ground conductor wire, and the ground conductor layer is connected to the shield layer of the shield tape 2 through the hole 14. Connected to.

FIGS. 2A and 2B are a plan view of the shield layer 2 of the shield tape 2 and a cross-sectional view taken along the line AA '. The shield tape 2 has a metal deposition layer 22 formed as a shield layer on the entire surface of a resin film 21 as a shield base material. A thin, insulative adhesive layer 3 containing no metal filler is applied over the entire surface of the metal deposition layer 22, and a conductive adhesive layer 4 containing a metal filler is printed thereon as an array of island patterns. ing. In the case of the figure, the conductive adhesive layer 4 is printed as a circular dot pattern.

When such a shield tape 2 is wound around the flat cable body 1 and rolled (that is, heated and pressed), the island-shaped conductive adhesive layer 4 is locally applied to the underlying thin insulating adhesive layer 3. As a result of the application of pressure, the conductive adhesive layer 4 mixes with the insulating adhesive layer 3. More specifically, the metal filler in the conductive adhesive layer 4 penetrates the insulating adhesive layer 3 and reaches the metal deposition layer 22, whereby the conductive adhesive layer 4 is electrically connected to the metal deposition layer 22. I do. In the hole 14 of the flat cable main body 1, the ground conductor wire is electrically connected via the conductive adhesive layer 4 to the metal deposition layer 22 serving as a shield layer.

FIG. 2C shows a schematic cross-sectional structure of the shield tape 2 after crimping to the flat cable body.
It is shown corresponding to FIG. As a result of the pressure applied to the lower insulating adhesive layer 3 via the conductive adhesive layer 4, the lower and lateral sides of the conductive adhesive layer 4 are electrically conductive with the insulating adhesive layer 3 due to the diffusion affinity of the metal filler. 4 and a mixed layer 5.

According to this embodiment, the thin insulating adhesive layer formed on the entire surface of the metal deposition layer of the shield tape serves as a buffer against stress, and the situation where the metal deposition layer is broken at the bent portion of the shield flat cable is prevented. In addition, since the conductive adhesive layer is arranged in a small island pattern, local stress is applied from the conductive adhesive layer to the insulating adhesive layer at the time of press bonding, and the conductive adhesive layer and the insulating adhesive layer are mixed. As a result, good electrical continuity can be obtained. In addition, a complicated process of alternately printing a conductive adhesive layer and an insulating adhesive layer with a stripe pattern is not required to ensure bending resistance.

[0014]

As described above, according to the present invention, a shielded flat cable with improved bending resistance can be obtained without requiring complicated steps.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shielded flat cable according to an embodiment of the present invention.

FIG. 2 is a plan view and a sectional view of a shield tape used for the shield flat cable.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flat cable main body, 11, 13 ... Insulation layer, 12
... conductor wire, 2 ... shield tape, 21 ... resin film (shield base material), 22 ... metal deposition layer (shield layer),
3 ... insulating adhesive layer, 4 ... conductive adhesive layer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidefumi Otsuka 1440 No.Mitsuzaki, Sakura City, Chiba Prefecture, etc. Inside Fujikura Sakura Office (72) Inventor Hirotaka Sawada 1440, Misaki, Sakura City, Chiba Prefecture Fujikura Sakura Business, etc. In-house F term (reference) 5G311 CA01 CB01 CC01 CD03 CE04 5G313 AB05 AC06 AD01 AE01 AE08 5G319 EA02 EA04 EB06 EC04

Claims (3)

[Claims] 1. A shielded flat cable in which a flat cable body in which a plurality of conductor wires are disposed inside an insulating layer is covered with a shield tape, wherein the shield tape is formed of a metal as a shield layer on a surface of a tape base material. A vapor-deposited layer is formed, an insulating adhesive layer is applied on the entire surface of the metal-deposited layer, and a conductive adhesive layer is printed in a predetermined pattern on the surface of the insulating adhesive layer, and the conductive adhesive layer is A shielded flat cable which is thermocompression bonded to the flat cable body so as to be mixed with an adhesive layer and connected to the metal deposition layer. 2. A method for manufacturing a shielded flat cable by covering a flat cable body having a plurality of conductor wires disposed inside an insulating layer with a shield tape, comprising: a metal deposition layer as a shield layer on a surface of the tape base material; An insulating adhesive layer is applied to the entire surface of the metal vapor-deposited layer of the shield tape on which is formed, and a conductive adhesive layer is printed with a predetermined pattern on the surface of the insulating adhesive layer. A method for manufacturing a shielded flat cable, comprising: bonding the shield tape to the flat cable main body so as to be mixed with an adhesive layer and connected to the metal deposition layer. 3. The method according to claim 2, wherein the conductive adhesive layer is printed as an array of island patterns.