CN-122000128-A - Dynamically stable shielding signal cable and preparation method thereof

CN122000128ACN 122000128 ACN122000128 ACN 122000128ACN-122000128-A

Abstract

The invention discloses a dynamic stable shielding signal cable and a preparation method thereof, wherein the cable comprises a conductor, an insulating layer coated outside the conductor and a multilayer shielding structure coated outside the insulating layer; the multi-layer shielding structure comprises an inner shielding layer and a composite shielding layer, wherein the composite shielding layer is a multi-layer composite belt and comprises a metal conductive layer and at least two polymer bonding layers, a melt blending interface is arranged between the inner shielding layer and the composite shielding layer, and the melt blending interface is formed by combining and solidifying the polymer bonding layer positioned in an inner side area with the back surface of the inner shielding layer in a melt state. According to the invention, the shielding effectiveness retaining capacity of the cable under the dynamic bending working condition is remarkably improved by enabling the multi-layer shielding layers to form the integrated structure with cooperative deformation.

Inventors

QIAN HUIFANG
ZHOU ZHANGXIAN
ZHOU JIANG
XIA LANLAN
YE JIACHENG

Assignees

江苏通鼎光电科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The dynamically stable shielding signal cable is characterized by comprising a conductor, an insulating layer coated outside the conductor and a multilayer shielding structure coated outside the insulating layer; The multi-layer shielding structure comprises an inner shielding layer and a composite shielding layer; The composite shielding layer is a multilayer composite belt and comprises a metal conductive layer and at least two polymer bonding layers positioned on the inner side of the metal conductive layer, wherein among the at least two polymer bonding layers, the polymer bonding layer positioned in the outer side area has a first melting point Tm1, and the polymer bonding layer positioned in the inner side area and facing the inner shielding layer has a second melting point Tm2, and Tm1 is smaller than Tm2; A melt blending interface is arranged between the inner shielding layer and the composite shielding layer, and the melt blending interface is formed by combining and solidifying a polymer bonding layer positioned in an inner side area with the back surface of the inner shielding layer in a melt state; the inner shielding layer, the melt blending interface and the composite shielding layer form an integrated shielding core body; the forming process of the melt blending interface comprises the steps of wrapping the composite shielding layer outside the inner shielding layer, enabling the composite shielding layer to be in a temperature interval lower than Tm2 and higher than Tm1, and enabling the composite shielding layer to be in a temperature interval not lower than Tm 2.
2. The dynamically-stabilized shielded signal cable of claim 1, wherein the inner shield layer is a soft magnetic alloy foil or a metal foil, and a thermoplastic adhesive layer is provided on a side facing the insulating layer and is bonded to a surface of the insulating layer through the thermoplastic adhesive layer.
3. The dynamically-stabilized shielded signal cable of claim 1, wherein the multilayer composite tape further comprises a polymeric carrier film positioned between the polymeric adhesive layer of the outer region and the polymeric adhesive layer of the inner region.
4. The dynamically-stabilized shielded signal cable of claim 1, wherein the second melting point Tm2 differs from the first melting point Tm1 by no less than 15 ℃.
5. The dynamically stabilized shielded signal cable of claim 1, wherein the polymer adhesive layer in the outer region is an ethylene-vinyl acetate copolymer or an ethylene-acrylate copolymer and the polymer adhesive layer in the inner region is a copolyamide or a modified polyolefin.
6. The dynamically-stabilized shielded signal cable of claim 1, wherein the melt blending interface has a 180 ° peel strength of not less than 2.5N/mm as measured by ASTM D903.
7. The dynamically stabilized shielded signal cable of claim 1, wherein the unitary shield core has a shield effectiveness attenuation value of no more than 3dB at the 3GHz frequency point after undergoing 5000 dynamic bending cycles specified by the IEC 61196-1 standard.
8. The dynamically stable shielded signal cable of claim 1, wherein the insulating layer is composed of a low dielectric loss composite material and comprises, by weight, 40-60 parts of metallocene polyethylene, 20-30 parts of styrenic thermoplastic elastomer, and 10-20 parts of spherical silica surface-modified with a coupling agent.
9. The dynamically-stabilized shielded signal cable of claim 1, wherein the multi-layer shield structure further comprises an outer shield layer disposed outside the composite shield layer, the outer shield layer being a woven wire layer, and an outer surface of the woven wire layer being calendared.
10. A method of preparing a dynamically stabilized shielded signal cable according to any one of claims 1 to 9, comprising the step of forming said integral shield core in-line, the step comprising: forming an inner shielding layer outside the conductor coated with the insulating layer; Wrapping the multilayer composite tape outside the inner shielding layer, and enabling the wire core formed after wrapping to sequentially pass through at least two heating areas with different temperatures, wherein: the temperature of the first heating zone is controlled to be lower than Tm2 but higher than Tm1; the temperature of the second heating zone is controlled to be not lower than Tm2, so that the polymer bonding layer positioned in the inner side area is melted and contacted with the back surface of the inner shielding layer; And cooling the wire core passing through the second heating zone to solidify the melted polymer bonding layer, so as to form the melt blending interface.

Description

Dynamically stable shielding signal cable and preparation method thereof Technical Field The invention relates to the technical field of transmission cables, in particular to a dynamic stable shielding signal cable and a preparation method thereof. Background In the application scenarios with extremely high requirements on signal integrity, such as data centers, high-performance computing, precise measuring instruments, industrial automation, and the like, the transmission cable not only needs to have high shielding efficiency under static state, but also faces the serious challenge of keeping the electromagnetic shielding performance stable for a long time under the dynamic mechanical stress of long-term running of equipment, repeated bending or moving of the cable, and the like. This is a key technical bottleneck to ensure system reliability and data accuracy. The conventional multi-layer shielding cable (such as a metal wire braid and aluminum plastic composite tape wrapping structure or a double-layer aluminum foil wrapping structure) widely used at present has the following defects under dynamic working conditions: The interlayer slippage causes unstable electrical contact, namely, the layers of the traditional shielding structure are usually only in physical contact or are simply attached through a low-viscosity adhesive tape, and the interlayer binding force is weak. When the cable is repeatedly bent, the materials of all layers generate relative slippage due to the modulus difference, so that the contact resistance fluctuation between metal layers is increased, even microscopic fatigue damage of the metal foil layer or the braided wire is caused, and the shielding effectiveness is irreversibly deteriorated. The low-frequency magnetic field shielding material and the flexibility are difficult to be compatible, and the effect of the conventional copper and aluminum shielding layer is limited for the low-frequency magnetic field interference lower than 1 MHz. Although the high magnetic permeability material (such as permalloy) has good shielding effect, the high magnetic permeability material has large brittleness, is easy to generate microcracks during bending, damages a magnetic conduction path, and is difficult to meet the requirement of dynamic application reliability. The high frequency shielding 'dynamic leakage' problem is that the metal wire braid mainly depends on reflection loss to play a role in a high frequency band, but the shielding effect is extremely sensitive to coverage rate. When the cable is bent, the relative position and angle of the braided wires change, resulting in local mesh enlargement and coverage reduction, thereby forming electromagnetic leakage channels that vary with the state of bending. Aiming at the problems, common improvement ideas such as increasing the weaving density, increasing the thickness of the metal foil or adding the conductive adhesive layer, although the initial shielding value is improved to a certain extent, the fundamental structural defect of independent deformation of each layer is not changed. It has been widely recognized in the art that the relative displacement between the shield layers must be allowed to some extent in order to maintain the necessary flexibility of the cable, which has limited the solution to the dynamic shield stability problem. Accordingly, there is a need to provide an improved shielding structure design that allows the cooperative deformation of the multiple shielding layers under dynamic bending conditions, reducing the relative displacement between the layers, and thus maintaining long-term stability of shielding effectiveness in a composite environment of mechanical stress and electromagnetic interference. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a dynamically stable shielding signal cable and a preparation method thereof. According to the invention, the shielding effectiveness retaining capacity of the cable under the dynamic bending working condition is remarkably improved by enabling the multi-layer shielding layers to form the integrated structure with cooperative deformation. In order to achieve the technical purpose and the technical effect, the invention is realized by the following technical scheme: In a first aspect, the present invention provides a dynamically stable shielded signal cable, comprising a conductor, an insulating layer coated outside the conductor, and a multilayer shielding structure coated outside the insulating layer; The multi-layer shielding structure comprises an inner shielding layer and a composite shielding layer; The composite shielding layer is a multilayer composite belt and comprises a metal conductive layer and at least two polymer bonding layers positioned on the inner side of the metal conductive layer, wherein among the at least two polymer bonding layers, the polymer bonding layer positioned in the outer side area has a first