FFC wire for improving signal integrity

Abstract

The utility model relates to signal transmission technical field especially a kind of FFC wire rod for improving signal integrity, a kind of FFC wire rod for improving signal integrity, including conductor, first insulating layer, second insulating layer, shielding layer and reinforcing structure;One side the both ends of the shielding layer are equipped with the reinforcing structure, and the reinforcing structure is attached to the first insulating layer;The reinforcing structure includes the base material layer, electromagnetic wave shielding layer and pressure sensitive adhesive layer that are sequentially laminated, the pressure sensitive adhesive layer is attached to the first insulating layer;The length of the punched region between the both end portions of the second insulating layer and the conductor is equal to the length of the reinforcing structure, and the punched region and the reinforcing structure are arranged in alignment, solve the characteristic impedance of the port of traditional FFC wire rod and the characteristic impedance difference of wire body is larger, signal integrity is influenced.

Description

Technical Field

[0001] This utility model relates to the field of signal transmission technology, and in particular to an FFC cable for improving signal integrity. Background Technology

[0002] Traditional FFC cables are composed of PET insulation material, a certain thickness of fire-retardant insulating adhesive, and conductors. However, the characteristic impedance at the port fluctuates significantly from the characteristic impedance of the cable body. This is because the cable body has a shielding layer to achieve the target characteristic impedance, while the port generally only has a reinforcing plate to enhance its mechanical strength, without a shielding layer. This results in a large difference between the characteristic impedance at the port and the characteristic impedance of the cable body, with the impedance difference reaching over 17Ω. This increases signal reflection, leading to greater electromagnetic interference and affecting signal integrity, thus failing to meet the higher signal transmission requirements of PCIe 5.0 and PCIe 6.0. Utility Model Content

[0003] To address the aforementioned shortcomings, the purpose of this invention is to propose an FFC cable that improves signal integrity, thereby solving the problem that the characteristic impedance at the port of traditional FFC cables differs significantly from the characteristic impedance of the cable body, thus affecting signal integrity.

[0004] To achieve this objective, the present invention adopts the following technical solution: An FFC cable for improving signal integrity includes a conductor, a first insulation layer, a second insulation layer, a shielding layer, and a reinforcing structure. The conductor has a first insulating layer and a second insulating layer attached to its upper and lower surfaces, respectively. The shielding layer is attached to the side of the first insulating layer and the second insulating layer away from the conductor. The shielding layer on one side has a reinforcing structure at both ends, and the reinforcing structure is attached to the first insulating layer. The reinforcing structure includes a substrate layer, an electromagnetic wave shielding layer, and a pressure-sensitive adhesive layer stacked sequentially, wherein the pressure-sensitive adhesive layer is bonded to the first insulating layer; The two ends of the second insulating layer have punched areas between them and the conductor. The length of the punched areas is equal to the length of the reinforcing structure, and the punched areas are vertically aligned with the reinforcing structure.

[0005] Preferably, the electromagnetic wave shielding layer is an aluminum foil layer, and the thickness of the electromagnetic wave shielding layer is 0.6-20μm.

[0006] Preferably, the length of the shielding layer is the same as the length of the second insulating layer.

[0007] Preferably, the thickness of the pressure-sensitive adhesive layer is 20-60 μm.

[0008] Preferably, the thickness of the first insulating layer and the second insulating layer is 20-400 μm.

[0009] Preferably, the electromagnetic wave shielding layer is a metal plating layer or a metal mesh layer.

[0010] Preferably, the substrate layer is a PET layer.

[0011] Preferably, the first insulating layer and the second insulating layer are connected to the conductor by thermocompression, the first insulating layer and the second insulating layer are connected to the shielding layer by thermocompression, and the reinforcing structure is connected to the first insulating layer by thermocompression.

[0012] The technical solution provided by this utility model can include the following beneficial effects: The reinforcement structure replaces the traditional reinforcement plate. The reinforcement structure consists of a substrate layer, a metal layer, and a pressure-sensitive adhesive layer. It can adjust the characteristic impedance value of the FFC wire port, making the characteristic impedance of the FFC wire body and the port similar. At the same time, the length of the reinforcement structure is flush with the punched area, so that the shielding layer and the reinforcement structure have a smooth transition, avoiding sudden increases and decreases in characteristic impedance value, reducing signal reflection, reducing electromagnetic interference, and thus improving signal integrity. Attached Figure Description

[0013] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the reinforcing structure of one embodiment of the present invention.

[0015] Figure 3 This is a structural diagram of a traditional FFC cable.

[0016] The structure includes: conductor 1, first insulating layer 21, second insulating layer 22, shielding layer 3, reinforcing structure 4, substrate layer 41, electromagnetic wave shielding layer 42, pressure-sensitive adhesive layer 43, perforated area 5, and reinforcing plate 6. Detailed Implementation

[0017] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0018] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, features defined with "first" and "second" may explicitly or implicitly include one or more of these features, used to distinguish and describe features, without any order or emphasis.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] An FFC cable for improving signal integrity includes a conductor 1, a first insulation layer 21, a second insulation layer 22, a shielding layer 3, and a reinforcing structure 4; The conductor 1 has a first insulating layer 21 and a second insulating layer 22 attached to its upper and lower surfaces, respectively. The shielding layer 3 is attached to the side of the first insulating layer 21 and the second insulating layer 22 away from the conductor 1. The reinforcing structure 4 is provided at both ends of the shielding layer 3 on one side, and the reinforcing structure 4 is attached to the first insulating layer 21. The reinforcing structure 4 includes a substrate layer 41, an electromagnetic wave shielding layer 42, and a pressure-sensitive adhesive layer 43 stacked sequentially, wherein the pressure-sensitive adhesive layer 43 is bonded to the first insulating layer 21. The two ends of the second insulating layer 22 are provided with punched areas 5 between them and the conductor 1. The length of the punched areas 5 is equal to the length of the reinforcing structure 4, and the punched areas 5 and the reinforcing structure 4 are aligned vertically.

[0021] Traditional FFC cables use a reinforcing plate 6 at the port, lacking a shielding layer 3 and shielding functionality. This results in a significant difference between the characteristic impedance at the port and the characteristic impedance of the cable body, increasing signal reflection, electromagnetic interference, and affecting signal integrity. Therefore, to meet the higher signal transmission requirements of PCIe 5.0 and PCIe 6.0, this invention proposes an FFC cable that improves signal integrity, such as... Figure 1 and Figure 2As shown, the reinforcing structure 4 includes a substrate layer 41, an electromagnetic wave shielding layer 42, and a pressure-sensitive adhesive layer 43. The electromagnetic wave shielding layer 42 can be a metal layer with electromagnetic wave shielding function, such as an aluminum foil layer, a metal plating layer, or a metal mesh. The reinforcing structure 4 has a shielding effect, which can effectively achieve electromagnetic shielding while ensuring mechanical strength, stabilizing the dielectric environment, and reducing the difference between the characteristic impedance at the FFC wire port and the characteristic impedance of the FFC wire body. This matches the characteristic impedance at the FFC wire port and the wire body to be close. At the same time, the length of the reinforcing structure 4 is the same as the length of the punched area 5. Therefore, the characteristic impedance from the shielding layer 3 to the reinforcing structure 4 is a smooth transition, without sudden increases or decreases in characteristic impedance value. This reduces signal reflection, reduces electromagnetic interference, and thus improves signal integrity, solving the problem of large characteristic impedance difference between the traditional FFC wire port and the wire body, which affects signal integrity.

[0022] The thickness of the pressure-sensitive adhesive layer 43 can change the insulation distance between the electromagnetic wave shielding layer 42 and the conductor 1. Therefore, the change in the thickness of the pressure-sensitive layer can adjust the characteristic impedance at the port of the FFC wire. In specific applications, the thickness of the reinforcing structure 4 needs to be adjusted according to the characteristic impedance value of the FFC wire body to adjust the characteristic impedance value of the FFC wire port, so that the characteristic impedance at the FFC wire port is similar to that of the wire body, thereby reducing the characteristic impedance difference between the FFC wire port and the wire body.

[0023] Specifically, comparing traditional FFC cables with the FFC cable for improving signal integrity proposed in this invention, the structure of traditional FFC cables is as follows: Figure 3 As shown, traditional FFC cables also have the same structure of conductor 1, first insulation layer 21, second insulation layer 22, and shielding layer 3. The difference is that they use a reinforcing plate 6, which does not have a shielding function, and the length of the reinforcing plate 6 is not flush with the length of the perforated area 5. Comparing the two types of FFC cables, under the same characteristic impedance of the cable body, the difference between the characteristic impedance at the port and the characteristic impedance of the cable body is large for traditional FFC cables, ranging from 17 to 27 Ω. In contrast, the difference between the characteristic impedance at the port and the characteristic impedance of the cable body proposed in this invention is only 1 to 4 Ω. It can be seen that compared with traditional FFC cables, the FFC cables proposed in this invention can effectively reduce the difference between the characteristic impedance at the port and the characteristic impedance of the cable body. As a result, compared with traditional FFC cables, the absolute values ​​of attenuation at 5 GHz and 16 GHz are reduced, and the value of the maximum eye diagram is increased, meeting the higher signal transmission requirements of PCIe 5.0 and PCIe 6.0.

[0024] The first insulating layer 21 and the second insulating layer 22 can be flexible insulating film materials such as polyester film or polyimide film.

[0025] The metal used in the electromagnetic wave shielding layer 42 is a metal material with the function of shielding electromagnetic waves, which can be aluminum foil or copper foil.

[0026] Preferably, the electromagnetic wave shielding layer 42 is an aluminum foil layer, and the thickness of the electromagnetic wave shielding layer 42 is 0.6-20μm.

[0027] Specifically, aluminum foil has good processing performance and low cost. The electromagnetic wave shielding layer 42 is an aluminum foil layer with a thickness of 0.6-20μm, which can have a good shielding function against electromagnetic interference. While ensuring that the electromagnetic wave shielding layer 42 has a corresponding anti-interference effect, it also ensures that the electromagnetic wave shielding layer 42 has good mechanical strength, achieves a reinforcement effect, and meets the flexibility requirements of FFC wire.

[0028] Preferably, the length of the shielding layer 3 is the same as the length of the second insulating layer 22.

[0029] Specifically, the reinforcing structure 4 is flush with the length of the perforated area 5, and the length of the shielding layer 3 is the same as the length of the second insulating layer 22, ensuring that the shielding layer 3 and the reinforcing structure 4 together completely cover the length range of the conductor 1, thereby achieving the effect of anti-interference.

[0030] Preferably, the thickness of the pressure-sensitive adhesive layer 43 is 20-60 μm.

[0031] Specifically, the pressure-sensitive adhesive layer 43 ensures that the reinforcing structure 4 adheres to the first insulating layer 21, and the thickness of the pressure-sensitive adhesive layer 43 is limited to 20-60μm. This reduces the possibility of bonding failure and bubble residue during the production of the reinforcing structure 4, ensuring that the reinforcing structure 4 can function normally and achieve anti-interference effect.

[0032] Preferably, the thickness of the first insulating layer 21 and the second insulating layer 22 is 20-400 μm.

[0033] Specifically, the first insulating adhesive layer and the second insulating layer 22 are used to bond the conductor 1 and the shielding layer 3, preventing the surface of the conductor 1 of the FFC wire from being exposed. The thickness of the first insulating layer 21 and the second insulating layer 22 is limited to 20-400μm, which satisfies the bonding requirements while also meeting most of the requirements for characteristic impedance and conductor specification adjustment.

[0034] Preferably, the electromagnetic wave shielding layer 42 is a metal plating layer or a metal mesh layer.

[0035] Specifically, the electromagnetic wave shielding layer 42 needs to meet the anti-interference effect and also have a corresponding reinforcement effect. The electromagnetic wave shielding layer 42 is a metal plating layer, and the thickness of the electromagnetic wave shielding layer 42 can be precisely controlled to meet different thickness requirements. The electromagnetic wave shielding layer 42 is a metal mesh layer, which has high flexibility and is resistant to bending, reducing the risk of the electromagnetic wave shielding layer 42 breaking due to bending.

[0036] Preferably, the substrate layer 41 is a PET layer.

[0037] Specifically, PET film has the characteristics of excellent anti-oxidation and anti-aging properties, good toughness, high impact strength and excellent electrical insulation. It can still maintain good anti-electromagnetic interference performance at high frequencies. Therefore, it is beneficial to increase the electromagnetic shielding performance of the reinforcing structure 4.

[0038] Preferably, the first insulating layer 21 and the second insulating layer 22 are connected to the conductor 1 by thermo-pressing, the first insulating layer 21 and the second insulating layer 22 are connected to the shielding layer 3 by thermo-pressing, and the reinforcing structure 4 is connected to the first insulating layer 21 by thermo-pressing.

[0039] Specifically, the hot-press connection is simple to operate and improves the fit between the conductor 1 and the first insulating layer 21 and the second insulating layer 22, as well as between the reinforcing structure 4 and the first insulating layer 21.

[0040] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without any inventive effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. An FFC cable for improving signal integrity, characterized in that: It includes a conductor, a first insulating layer, a second insulating layer, a shielding layer, and a reinforcing structure; The conductor has a first insulating layer and a second insulating layer attached to its upper and lower surfaces, respectively. The shielding layer is attached to the side of the first insulating layer and the second insulating layer away from the conductor. The shielding layer on one side has a reinforcing structure at both ends, and the reinforcing structure is attached to the first insulating layer. The reinforcing structure includes a substrate layer, an electromagnetic wave shielding layer, and a pressure-sensitive adhesive layer stacked sequentially, wherein the pressure-sensitive adhesive layer is bonded to the first insulating layer; The two ends of the second insulating layer have punched areas between them and the conductor. The length of the punched areas is equal to the length of the reinforcing structure, and the punched areas are vertically aligned with the reinforcing structure.

2. The FFC cable for improving signal integrity according to claim 1, characterized in that: The electromagnetic wave shielding layer is an aluminum foil layer, and the thickness of the electromagnetic wave shielding layer is 0.6-20μm.

3. The FFC cable for improving signal integrity according to claim 1, characterized in that: The length of the shielding layer is the same as the length of the second insulating layer.

4. The FFC cable for improving signal integrity according to claim 1, characterized in that: The thickness of the pressure-sensitive adhesive layer is 20-60 μm.

5. The FFC cable for improving signal integrity according to claim 1, characterized in that: The thickness of the first insulating layer and the second insulating layer is 20-400 μm.

6. The FFC cable for improving signal integrity according to claim 1, characterized in that: The electromagnetic wave shielding layer is a metal plating layer or a metal mesh layer.

7. The FFC cable for improving signal integrity according to claim 1, characterized in that: The substrate layer is a PET layer.

8. The FFC cable for improving signal integrity according to claim 1, characterized in that: The first insulating layer and the second insulating layer are connected to the conductor by thermocompression, the first insulating layer and the second insulating layer are connected to the shielding layer by thermocompression, and the reinforcing structure is connected to the first insulating layer by thermocompression.

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