DE-102017219845-B4 - Shielded flat cable, cable harness and shielding element

Abstract

Shielded flat cable, with: a large number of ladders arranged parallel to each other; an insulating sheathing section which covers the multiple conductors and has an exposed conductor section which exposes part of at least one of the conductors; and a shielding element that covers an outer circumference of the sheathing section, wherein the part of at least one of the conductors is electrically connected to the shielding element via the exposed conductor section; wherein the shielding element comprises a first layer of shielding material for blocking external interference noise and a second layer of binder resin containing a metal filler, the second layer being designed to make contact with the conductor via the exposed conductor section; and wherein the metal filler is made of silver, the D90 particle diameter of the metal filler contained in the binder resin is 6.7µm to 29.1µm, and the difference between a D10 particle diameter and a D95 particle diameter of the metal filler is 6.4µm or more, and wherein the metal filler is contained in the second layer in an amount of 65 wt.% or more.

Inventors

• Hiroki Kondo
• Mizuki SHIRAI
• Daisuke Suzuki

Assignees

• YAZAKI CORPORATION

Dates

Publication Date

20260513

Application Date

20171108

Priority Date

20161110

Claims (5)

1. Shielded flat cable comprising: a plurality of conductors arranged parallel to one another; an insulating sheath section covering the plurality of conductors and having an exposed conductor section exposing a portion of at least one of the conductors; and a shielding element covering an outer circumference of the sheath section, wherein the portion of at least one of the conductors is electrically connected to the shielding element via the exposed conductor section; wherein the shielding element comprises a first layer of shielding material for blocking external interference and a second layer of binder resin containing a metal filler. holding, wherein the second layer is provided to establish contact with the conductor via the exposed conductor section; and wherein the metal filler is made of silver, a D90 particle diameter of the metal filler contained in the binder resin is 6.7µm to 29.1µm, and a difference between a D10 particle diameter and a D95 particle diameter of the metal filler is 6.4µm or more, and wherein the metal filler is contained in the second layer in an amount of 65 wt.% or more.
2. Shielded flat cable to Claim 1 , wherein the contact resistance between the second layer and the conductor over the exposed conductor section is 100mΩ or less, and the bond strength between the second layer and the conductor over the exposed conductor section is 0.3N/19mm or more.
3. Shielded flat cable to Claim 1 or 2 , wherein the exposed conductor section is provided to expose a side section of a conductor located at one end of the plurality of conductors; and wherein the shielding element is wound one or more turns around the sheathing section.
4. Wiring harness, including: the shielded flat cable after one of the Claims 1 until 3 ; and a pressure contact connector that is connected to an end section of the shielded flat cable.
5. Shielding element comprising: a first layer of shielding material for blocking external interference; and a second layer of binder resin containing a metal filler, where the metal filler is made of silver, the D90 particle diameter of the metal filler contained in the binder resin is 6.7 µm to 29.1 µm, and the difference between a D10 particle diameter and a D95 particle diameter of the metal filler contained in the binder resin is 6.4 µm or more, and wherein the metal filler is present in the second layer in an amount of 65 wt.% or more.

Description

Background of the invention 1. Field of the invention The present invention relates to a shielded flat cable, a cable harness and a shielding element. 2. Description of the related technology Recently, shielded electrical wires have become known in which each individual wire is completely coated with a shielding layer, such as metal foil or braid, to prevent malfunctions of various types of electronic devices due to external interference. Shielded flat cables have also been proposed, in which each flat wire is provided with a shielding layer. In this type of shielded flat cable, the sheathing section of a conductor used as one of the many parallel conductors of the flat cable, serving as a ground wire, is removed to form an exposed conductor section, and the outer circumference of the flat cable is coated with a shielding element. The shielding element has a first layer, made, for example, of metal foil, which serves as a shielding layer to block external interference, and a second layer made of an adhesive layer containing a conductive filler or of conductive paste. The shielding element is wrapped around the flat cable with the second layer facing inwards, whereby the adhesive layer containing the conductive filler, or the conductive paste, is positioned between the shielding layer and the exposed conductor section from which the sheathing has been removed, and the leakage wire is electrically connected to the shielding layer via this interposed substance (reference to JP 2008- 4 464 A and JP 2011- 165 393 A ). Regarding the shielded flat cables according to JP 2008- 4 464 A and JP 2011- 165 393 A However, the intervening substance between the conductor wire and the shielding layer has not been sufficiently investigated, and the electrical connection between the conductor and the shielding layer lacks stability, and there is a possibility that smooth grounding of an interference noise may be hindered. The JP 2002- 184 245 A This describes a shielded flat cable. In this shielded flat cable, several flat conductors, including at least one grounding wire and a signal line that excludes at least part of the grounding wire, are integrally covered with an insulator, and a shielding tape is applied over this. A conductive adhesive layer is provided in such a way that it is in contact with the non-insulating part of the grounding wire. JP H10- 251 606 A This describes a conductive adhesive. The conductive adhesive is formed, for example, from a thermoplastic resin containing a conductive filler of 70 to 95 wt%. The conductive filler is, for example, a conductive metal (e.g., silver) and has a particle size of 0.1–10 µm. JP 2 649 946 B2 This describes a conductive adhesive. A base comprising an adhesive made of a synthetic resin is kneaded with, for example, a first flaky metal powder (e.g., silver), and the mixture in the mixer is stirred by rotating a propeller with a sharp edge, thereby breaking up the edges of the flakes of metal powder to form a second flaky metal powder. In this way, the present adhesive contains at least two types of flaky metal powders that differ in the central values of the value distributions of (a+b)/2, where a is the length of the longitudinal area of a flake in the base, and b is the length in the direction intersecting it. Summary of the invention The present invention has been made to solve the above problems, and one object of the present invention is to provide a shielded flat cable, a cable harness and a shielding element that are able to increase the stability of the electrical connection between a conductor and a shielding layer. This problem is solved with a shielded flat cable according to claim 1, a cable harness according to claim 4 and a shielding element according to claim 5. A shielded flat cable according to the present invention is defined in claim 1 and comprises: a large number of ladders arranged parallel to each other; an insulating sheathing section covering the multiple conductors and having an exposed conductor section that exposes part of at least one of the conductors; and a shielding element that covers an outer circumference of the sheathing section, wherein the part of at least one of the conductors is electrically connected to the shielding element via the exposed conductor section; wherein the shielding element comprises a first layer made of shielding material for blocking external interference noise, and a second layer made of binder resin containing a metal filler, the second layer being designed to make contact with the conductor via the exposed conductor section; and wherein the metal filler is made of silver, the D90 particle diameter of the metal filler contained in the binder resin is 6.7µm to 29.1µm, and the difference between a D10 particle diameter and a D95 particle diameter of the metal filler is 6.4µm or more, and wherein the metal filler is contained in the second layer in an amount of 65 wt.% or more. In the shielded flat cable, the shiel