Conductive cloth, conductive foam and electronic equipment

Abstract

A conductive fabric, a conductive foam and an electronic device, the conductive fabric comprises a fabric base material, the fabric base material is formed by interweaving a plurality of strands of first wire harnesses and a plurality of strands of second wire harnesses, the fabric base material comprises a plurality of weaving units, each weaving unit is composed of a first wire harness segment and a second wire harness segment which are connected, a height difference exists between the surface of the first wire harness section and the surface of the second wire harness section; the conductive cloth further comprises a conductive material, and the conductive material covers the surface, facing a device to be connected, of the cloth base material. The conductive material covering the first surface and the second surface has a thickness difference; under the condition that the extrusion force applied to the conductive cloth is 0.2 N-0. 4N, the knitting units with the difference value between the thickness difference and the height difference smaller than or equal to a first threshold value are effective knitting units, and the ratio of the number of the effective knitting units to the number of the knitting units is larger than or equal to 50%. Therefore, the conductive cloth can be in full contact with a device to be connected under the condition of weak extrusion force.

Description

Conductive cloth, conductive foam and electronic device TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical connectors, and more particularly, to a conductive cloth, a conductive foam and an electronic device. BACKGROUND

[0002] In electronic devices such as mobile phones, televisions, displays, notebook computers, tablet computers, vehicle navigation systems, etc., conductive foam is often used to fill the gaps of electronic devices and connect the reference ground, or to electrically connect between the shielding cover of electronic components inside the electronic device and the reference ground, or to electrically connect between functional devices such as screens, camera modules, system on chips (SOC) and the reference ground.

[0003] When the conductive foam is applied to the connection scheme of functional devices such as screens, applying a large extrusion force to the conductive foam will cause film printing on the screen and affect the user experience. If the screen film printing is to be avoided, the extrusion force received by the conductive foam needs to be weakened, and weakening the extrusion force will make the conductive cloth and the screen unable to fully contact, which will cause the third harmonic to easily occur at the contact interface, and thus will bring the risk of failing to pass the radiated spurious emission (RSE) regulation test.

[0004] Therefore, how to achieve full contact with the device to be connected under weak extrusion force is a problem that needs to be solved in the industry.

[0005] SUMMARY

[0006] The purpose of the present application is to provide a conductive cloth, a conductive foam and an electronic device, which can improve the surface flatness of the conductive cloth by using conductive materials to compensate for the height difference of the cloth substrate, so that the surface of the conductive cloth can approach a plane under weak extrusion force, thereby achieving full contact with the device.

[0007] In a first aspect, the present application provides a conductive cloth for connecting with a device, comprising a cloth substrate and a conductive material, the cloth substrate is woven by interlacing a plurality of first strands and a plurality of second strands, the cloth substrate comprises a plurality of woven units, each woven unit is composed of an adjacent first strand segment and a second strand segment, the first strand segment is a segment of the first strand, the first strand segment is woven on the second strand, the second strand segment is a segment of the second strand, the second strand segment is woven on the first strand, the first strand segment has a height difference with the second strand segment towards a first surface of the device; the conductive material covers the surface of the cloth substrate towards the device, and the conductive material covering the first surface of the woven unit and the conductive material covering the second surface of the same woven unit are configured to have a thickness difference.

[0008] When the cloth substrate is applied with a pressure of 0.2N-0.4N, if the difference between the thickness difference and the height difference in the area corresponding to the woven unit on the cloth substrate is less than or equal to 5μm, the woven unit is an effective woven unit; wherein the ratio of the number of effective woven units on the cloth substrate to the number of woven units is greater than or equal to 50%.

[0009] The conductive cloth provided by the present application configures the conductive material covering the first surface of the woven unit and the conductive material covering the second surface of the woven unit to have a thickness difference, and at least 50% of the woven units satisfy that when the conductive cloth is applied with a pressure of 0.2N-0.4N, the difference between the thickness difference and the height difference of the first surface and the second surface is less than or equal to 5μm, that is, the thickness difference is approximately equal to the height difference, so as to compensate for the height difference of the cloth substrate by the conductive material, thereby improving the surface flatness of the conductive cloth. From a microscopic perspective, even under weak pressure, more conductive materials in the area corresponding to the woven unit move towards the device, so that more conductive materials in the area corresponding to the woven unit can be deformed by the device under pressure, thereby increasing the contact area between the conductive cloth and the device, that is, the conductive cloth can also be in full contact with the device under weak pressure, thereby increasing the conductive path between the conductive cloth and the device, and avoiding screen printing when the conductive cloth is applied to the screen connection scheme, in addition, the generation of third harmonic is also weakened, thereby ensuring that the radiation spurious test of the electronic device is successfully passed.

[0010] In a possible design, the effective woven unit comprises an effective first surface and an effective second surface, and the effective woven unit is configured such that when the conductive cloth is applied with a pressure of 0.2N-0.4N, the surface of the conductive material covering the effective first surface tends to be horizontal with the surface of the conductive material covering the effective second surface.

[0011] In the area corresponding to the effective weaving unit, the conductive material covering the effective weaving unit compensates for the height difference of the effective weaving unit itself, so that the surface of the conductive cloth in the area tends to be horizontal under weak extrusion pressure, thereby realizing sufficient contact with the device.

[0012] In a possible design, the difference between the thickness difference and the height difference is less than or equal to a first threshold value, which includes that the effective first surface includes the highest point of the effective weaving unit, and the effective second surface includes the lowest point of the effective weaving unit; or, the effective first surface includes the lowest point of the effective weaving unit, and the effective second surface includes the highest point of the effective weaving unit; the height difference between the highest point and the lowest point is a first value; the thickness difference between the conductive material covering the highest point and the conductive material covering the lowest point is a second value, and the difference between the first value and the second value is less than or equal to 5 μm.

[0013] Generally, the two points with the largest difference on the first surface and the second surface are selected, so that the highest point and the lowest point can be filled by the conductive material. When the thickness of the conductive material is configured to compensate for the height difference between the highest point and the lowest point, other points on the two surfaces can also be filled, thereby ensuring that the areas corresponding to the two surfaces are generally horizontal.

[0014] In a possible design, the difference between the thickness difference and the height difference is less than or equal to 3 μm.

[0015] Further reducing the first threshold value to 3 μm can further ensure the overall flatness of the area corresponding to each effective weaving unit, and further improve the flatness of the surface of the conductive cloth.

[0016] In a possible design, the conductive cloth is configured such that, under the condition of an extrusion pressure of 0.2 N to 0.4 N, the effective contact area fraction of the conductive cloth with the device is greater than or equal to 50%.

[0017] The effective contact area fraction of the conductive cloth with the device is greater than or equal to 50%, so that the effective contact area of the conductive cloth with the device surface is increased, and the conductive cloth has more contact area with the device, that is, the conductive cloth can also realize sufficient contact with the device under weak extrusion pressure, thereby increasing the conductive path of the conductive cloth and the device.

[0018] In a possible design, each first strand is a layer of first wire, and the first wire includes a plurality of first fiber filaments; and each second strand is a layer of second wire, and the second wire includes a plurality of second fiber filaments.

[0019] By reducing the number of layers of wire in each strand, the height difference of the cloth substrate itself can be reduced, so that the conductive material fills the height difference better.

[0020] In a possible design, the conductive material includes a metal plating layer, and a thickness of the metal plating layer is greater than or equal to 10 μm.

[0021] By thickening the thickness of the metal plating layer, such as controlling the thickness of the metal plating layer to be greater than or equal to 10 μm, it is ensured that at least 50% of the braided units can be compensated for the height difference by the thickness of the metal plating layer, so as to increase the effective contact area of the conductive cloth surface and the device surface. Under other conditions, compared with the conductive material of 5 μm, the harmonic current is significantly reduced.

[0022] In a possible design, the metal plating layer includes a copper layer, a nickel layer, and a gold layer, and a thickness of the gold layer is greater than or equal to 0.5 μm.

[0023] Since gold is more expensive than copper and nickel, the thickness of the copper layer and the nickel layer is usually greater than that of the gold layer, such as the sum of the thicknesses of the copper layer and the nickel layer being 9.5 μm, and the gold layer being 0.5-1 μm.

[0024] In a possible design, the metal plating layer includes a copper layer, a nickel layer, and a silver layer, and a thickness of the silver layer is greater than or equal to 0.5 μm.

[0025] The gold layer can also be replaced by a silver layer, that is, a stack (or plating layer) composed of silver, and under the same conditions, the PIM performance of silver is better than that of gold as a whole.

[0026] In a possible design, the conductive material is a conductive paste, and a thickness of the conductive paste is greater than or equal to 10 μm.

[0027] The conductive paste is a viscous paste composed of high-purity metal particles, a binder, a solvent, and an additive, and the mass ratio of the metal particles is usually greater than 60%. Since the conductive paste is in a liquid state during coating processing, before the conductive paste is solidified, the conductive paste flows on the surface of the cloth substrate, and based on the leveling effect of the liquid, the conductive paste of different thicknesses covers the first surface and the second surface with height differences, so that the surface area of the final conductive paste tends to be horizontal, thereby compensating for the height difference of the cloth substrate itself, improving the up-and-down undulation of the conductive cloth surface, and further improving the effective contact area between the conductive cloth and the device. Therefore, under the same working pressure, the harmonic current generated by the conductive cloth is smaller, that is, the working pressure of the conductive foam can be reduced under the premise of ensuring the harmonic level. The thickness of the conductive paste is greater than or equal to 10 μm, which can further improve the surface flatness.

[0028] In a possible design, the surface of the conductive cloth is coated with the conductive paste.

[0029] The conductive paste is coated on the surface of the conductive cloth in contact with the device. Since the conductive paste is in a liquid state before curing, the flatness of the surface of the conductive cloth can be improved.

[0030] In a possible design, the conductive material further includes a metal plating layer, and the cloth substrate, the metal plating layer, and the conductive paste are sequentially stacked in the thickness direction of the conductive cloth.

[0031] The surface of the cloth substrate can be covered with a metal plating layer, and the metal plating layer is further covered with the conductive paste, to further improve the flatness of the surface of the conductive cloth.

[0032] In a possible design, the cloth substrate has pores filled with the conductive paste.

[0033] Since the conductive paste contains adhesives and other substances, it has a certain viscosity. The conductive paste can seep out of the pores of the cloth substrate. Since the liquid has fluidity, the seeped conductive paste will flow around the pores. Based on the leveling effect, the height difference between the first surface and the second surface is compensated for, thereby improving the ups and downs of the surface of the conductive cloth, and further improving the effective contact area between the conductive cloth and the device.

[0034] In a possible design, the conductive material further includes a metal plating layer, and the surface of the conductive cloth facing the device includes the metal plating layer and the conductive paste.

[0035] The conductive paste seeping out of the pores is mainly used for filling. The surface of the cloth substrate can be coated with a metal plating layer. When the amount of the seeped conductive paste is small, the surface of the conductive cloth can be partly the metal plating layer and partly the conductive paste.

[0036] In a possible design, the material of the conductive paste includes at least one of conductive silver paste, conductive copper paste, conductive nickel paste, and conductive graphene paste.

[0037] The conductive paste is a mixture of conductive substances suspended or dispersed in a liquid medium. It mainly consists of two components: conductive particles and medium. The conductive particles are usually silver, copper, aluminum, and other metal materials, which have very high electrical conductivity and mechanical strength. The difference between the conductive silver paste, the conductive copper paste, the conductive nickel paste, and the conductive graphene paste lies in the different conductive particles, and the medium can all be organic substances.

[0038] In a possible design, part of the cloth substrate does not have the second wire harness.

[0039] Generally, the fabric substrate is deeply recessed at the weaving nodes, so that the conductive fabric presents a rough shape, further increasing the area and height difference value of the existing height difference, making it more difficult for the conductive material to compensate for the height difference. Therefore, the flatness of the fabric substrate itself can be further improved by reducing the weaving nodes, so that the overall surface of the fabric substrate itself is more close to a plane relative to the more fabric substrate of the weaving nodes, so as to reduce the area and thickness value of the height difference that needs to be compensated by the conductive material.

[0040] In a second aspect, the application also provides a conductive foam, comprising the conductive fabric of any one of the above.

[0041] The conductive foam in the application comprises a conductive fabric, the conductive fabric is configured to have a thickness difference between the conductive material covering the first surface of the weaving unit and the conductive material covering the second surface of the weaving unit, and at least 50% of the weaving units satisfy that under the condition that the conductive fabric is subjected to an extrusion force of 0.2N-0.4N, the difference between the thickness difference and the height difference of the first surface and the second surface is less than or equal to 5μm, that is, the thickness difference is approximately equal to the height difference, so as to compensate for the undulating height difference of the fabric substrate by the conductive material, thereby improving the surface flatness of the conductive fabric. From a microscopic perspective, even under the condition of weak extrusion force, the conductive material in the area corresponding to more weaving units is close to the device, so that the conductive material in the area corresponding to more weaving units can be deformed by the extrusion of the device, thereby enabling the conductive fabric to have more contact area with the device, that is, enabling the conductive fabric to achieve sufficient contact with the device under the condition of weak extrusion force, thereby increasing the conductive path between the conductive fabric and the device, and avoiding screen printing when the conductive fabric is applied to the screen connection scheme. In addition, the generation of third harmonic is also weakened, thereby ensuring the smooth passing of the radiation spurious test of the electronic equipment.

[0042] In a possible design, the conductive foam further comprises a foam core and an adhesive, and the conductive fabric is bonded to the surface of the foam core by the adhesive.

[0043] In a possible design, an insulating adhesive is further included, which is arranged on the surface of the foam core and used to bond the foam core to the component to be connected.

[0044] The insulating adhesive serves to bond and fix the conductive foam as a whole to the component to be connected. In addition, the insulating adhesive is mainly selected to improve the bonding strength. In the related art, the conductive foam is generally bonded and fixed as a whole by using conductive adhesive. However, since the conductive adhesive mainly comprises two parts of conductive particles (for conducting) and adhesive (for bonding), and the insulating adhesive only has adhesive, under the premise that the conductive adhesive and the insulating adhesive have the same weight, the insulating adhesive contains more adhesive, and therefore has greater bonding strength.

[0045] In a possible design, the insulating glue is located in the middle of the surface of the bubble core or adjacent to the edge.

[0046] When the insulating glue is located in the middle of the surface of the bubble core, the whole conductive foam is bonded to the part at the middle part, so that the fixed constraint point of the conductive foam is located in the middle part and can be kept stable, so as to improve the shock resistance of the conductive foam.

[0047] The insulating glue is adjacent to the edge of the bubble core, so that the fixed constraint point of the conductive foam is located at the edge. This design can be used in some narrow special installation scenes.

[0048] In a possible design, the surface of the bubble core has a reserved area without the conductive cloth.

[0049] The surface of the bubble core has a reserved area without the conductive cloth, so as to avoid false connection to the non-grounded part and facilitate installation of the conductive foam.

[0050] In a possible design, the number of the conductive cloths is two, and the two conductive cloths are oppositely arranged on the surface of the bubble core. The pores of the bubble core are filled with the conductive paste.

[0051] Since only the opposite two surfaces of the bubble core have the conductive cloths, and the peripheral wall of the bubble core does not have the conductive cloth, the volume of the conductive foam can be further reduced. Moreover, the pores of the bubble core are filled with the conductive paste, so that the conductive paste can electrically connect the upper and lower conductive cloths when the conductive foam is extruded, thereby ensuring that the conductive foam can be electrically connected.

[0052] In a possible design, the adhesive is the conductive paste, and the conductive paste seeps out of the pores of the cloth substrate to form a conductive material or part of the conductive material.

[0053] Since the conductive paste contains adhesives and other substances, it has a certain viscosity and can be used as an adhesive. When the conductive paste is used as an adhesive, the conductive paste can seep out of the pores of the cloth substrate. Since the liquid has fluidity, the seeped conductive paste will flow to the periphery of the pores. Based on the leveling effect, the height difference between the first surface and the second surface is compensated, so as to improve the ups and downs of the surface of the conductive cloth, and further improve the effective contact area between the conductive foam and the device.

[0054] In a third aspect, the application also provides an electronic device comprising the conductive foam according to any one of the above.

[0055] The electronic device in the embodiment can be installed more easily in the electronic device due to the miniaturization and thinness of the conductive foam, so as to reduce the manufacturing difficulty of the electronic device. Meanwhile, the conductive foam occupies less internal space, which is beneficial to the layout optimization of other functional components, so as to further reduce the manufacturing difficulty of the electronic device. In addition, the conductive foam applied to the screen grounding scheme can avoid screen printing and weaken or even avoid the generation of third harmonic, so as to ensure the smooth passing of the radiation spurious test of the electronic device.

[0056] In a possible design, the electronic device further includes a screen and a metal middle frame, and the device is the screen or the metal middle frame.

[0057] The conductive foam can be applied to the electrical connection scene of the screen and the middle frame. The upper surface of the conductive foam is connected with the screen, and the lower surface of the conductive foam is connected with the metal middle frame. For the conductive cloth on the upper surface of the conductive foam, the device is the screen. For the conductive cloth on the lower surface of the conductive foam, the device is the metal middle frame. BRIEF DESCRIPTION OF DRAWINGS

[0058] FIG. 1 is a schematic diagram of the conductive foam according to an embodiment of the present application;

[0059] FIG. 2 is a schematic diagram of the conductive cloth according to an embodiment of the present application;

[0060] FIG. 3 is a schematic diagram of a smart phone according to an embodiment of the present application;

[0061] FIG. 4 is a physical sectional view of A-A in FIG. 2;

[0062] FIG. 5 is a physical top view of the conductive cloth according to an embodiment of the present application;

[0063] FIG. 6 is a sectional view of the partial device of T-T in FIG. 3;

[0064] FIG. 7 is a sectional view of an example of the camera module of the smart phone according to an embodiment of the present application;

[0065] FIG. 8 is a sectional view of another example of the camera module of the smart phone according to an embodiment of the present application;

[0066] FIG. 9 is a sectional view of four embodiments of the conductive foam according to an embodiment of the present application;

[0067] FIG. 10 is a sectional view of another example of the conductive foam according to an embodiment of the present application;

[0068] FIG. 11 is a sectional view of another example of the conductive foam according to an embodiment of the present application;

[0069] FIG. 12 is a schematic diagram of the working principle of the conductive foam in FIG. 10;

[0070] Fig. 13 is a sectional view of another example of the conductive foam according to an embodiment of the present application;

[0071] Fig. 14 is a top view of an example of the cloth substrate according to an embodiment of the present application;

[0072] Fig. 15 is an equivalent matrix diagram of Fig. 14;

[0073] Fig. 16 is a sectional view of an example of E-E in Fig. 14;

[0074] Fig. 17 is a sectional view of an example of M-M in Fig. 14;

[0075] Fig. 18 is a sectional view of an example of the conductive cloth connected to the screen according to an embodiment of the present application;

[0076] Fig. 19 is a top view of the screen grounded through the conductive foam according to an embodiment of the present application;

[0077] Fig. 20 is a sectional view of an example of U-U in Fig. 19;

[0078] Fig. 21 is a top view of the circuit board grounded through the conductive foam according to an embodiment of the present application;

[0079] Fig. 22 is a sectional view of V-V in Fig. 21;

[0080] Fig. 23 is a schematic view of an example of the conductive cloth according to an embodiment of the present application;

[0081] Fig. 24 is a schematic view of another example of the conductive cloth according to an embodiment of the present application;

[0082] Fig. 25 is a schematic view of another example of the conductive cloth according to an embodiment of the present application;

[0083] Fig. 26 is a sectional view of an example of the conductive cloth according to an embodiment of the present application;

[0084] Fig. 27 is a schematic view of another example of the conductive cloth according to an embodiment of the present application.

[0085] Reference signs:

[0086] 10, first wire bundle; 11, first wire; 111, first fiber;

[0087] 20, second wire bundle; 21, second wire; 211, second fiber;

[0088] 100, conductive foam; 101, conductive cloth; 102, adhesive; 103, foam core; 103a, avoidance area; 104, insulating adhesive;

[0089] 1011, cloth substrate; 1012, conductive material;

[0090] 200, screen;

[0091] 300, case; 301, middle frame; 302, battery cover;

[0092] 400, circuit board; 401, electronic component; 402, solder pad;

[0093] 500, shielding cover;

[0094] 600, camera module; 601, steel sheet support; 602, copper foil;

[0095] 700, antenna. DETAILED DESCRIPTION

[0096] The following exemplary describes the related content that the embodiments of the present application can involve. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0097] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected or can communicate with each other; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0098] In the description of the present application, it should be understood that the terms "upper", "lower", "side", "inner", "outer", "top", "bottom" and the like indicate the orientation or positional relationship based on the installation, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0099] It should be further pointed out that in the embodiments of the present application, the same reference signs represent the same components or the same parts, and for the same parts in the embodiments of the present application, only one part or component may be taken as an example and marked with a reference sign in the drawing, and it should be understood that the reference sign is also applicable to other identical parts or components.

[0100] In the description of the present application, it should be noted that the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone.

[0101] In electronic devices such as mobile phones, televisions, displays, notebook computers, tablet computers, and car navigation systems, conductive foam is often used to fill the gaps of electronic devices and connect the reference ground, or to electrically connect the shielding cover of electronic components inside the electronic device and the reference ground, or to electrically connect functional devices such as screens, camera modules, and system-on-chip devices and the reference ground.

[0102] FIG. 1 is a schematic diagram of a conductive foam 100 in the related art.

[0103] As shown in FIG. 1, the current conductive foam 100 is usually composed of a foam core 103, an adhesive 102, and a conductive cloth 101. The conductive cloth 101 is fixed to the outside of the foam core 103 by the adhesive 102. When the conductive foam 100 is in contact with a device to be connected to achieve electrical connection, the current is mainly conducted through the conductive cloth 101, and the foam core usually mainly plays a supporting role. It can be understood that the device to be connected herein can also be referred to as a device.

[0104] As shown in FIG. 2, the conductive cloth 101 includes a cloth substrate 1011 and a conductive material 1012. The cloth substrate 1011 can be plated or coated with a conductive material 1012 such as gold, nickel, copper, etc., so that the conductive cloth 101 has conductive properties. The cloth substrate 1011 is usually plain cloth, which is usually woven by a plurality of warp threads and a plurality of weft threads using a multi-strand crossing weaving process. Each warp thread or each weft thread is usually composed of multiple layers of fiber filaments. In order to meet the increasingly high requirements of miniaturization of the whole machine, the conductive material 1012 is usually 3-7 μm under the premise of realizing conductivity.

[0105] However, the surface of the woven cloth substrate 1011 is up and down and has pores, and the conductive material 1012 covering the cloth substrate 1011 is thin, and its surface tends to follow the surface of the cloth substrate 1011, that is, the surface of the conductive cloth 101 ultimately formed by the lamination of the cloth substrate 1011 and the conductive material 1012 is uneven. When the conductive foam 100 is in contact with the device to be connected under normal working conditions, only a part of the area of the higher part of the surface of the conductive foam 100 can be in contact with the surface of the device to be connected. The lower part of the surface of the conductive foam 100 can only be in contact with the device to be connected under extreme compression (i.e., the extrusion force between the device to be connected and the conductive foam 100 is greater than a certain threshold). This results in that the conductive cloth 101 cannot be in full contact with the device to be connected under weak extrusion conditions, and the use scenarios are greatly limited. This will be described in detail below with reference to the accompanying drawings.

[0106] Fig. 3 is a schematic diagram of a smart phone according to an embodiment of the present application. In Fig. 3, (a) is a front view of the smart phone, and (b) is a back view of the smart phone. In the following, the conductive foam 100 is applied to the grounding of the screen 200, which is the device to be connected in the present example. The electrical connection between the conductive foam 100 and the screen 200 is described in detail.

[0107] Fig. 4 is a sectional view of A-A in Fig. 2. Fig. 5 is a top view of the conductive cloth 101. In Figs. 4 and 5, the conductive cloth 101 is a magnified photograph taken by an electron microscope, and the conductive cloth 101 in Figs. 4 and 5 is in a natural state without force. It can be understood that the conductive material 1012 is not shown in Figs. 4 and 5, and when the conductive material 1012 is thin, for example, less than 7 μm, the surface relief state of the conductive cloth 101 can be approximated to the relief state of the cloth base material 1011. Therefore, the conductive material 1012 is omitted in Figs. 4 and 5, but in fact, in Fig. 4, the conductive material 1012 is between the cloth base material 1011 and the screen 200, and in Fig. 5, the conductive material 1012 is on the cloth base material 1011. As can be seen from the sectional view of the conductive cloth 101 in Fig. 4, the warp 10' and the weft 20' of the conductive cloth 101 are composed of three layers of fiber filaments, wherein the A layer of fiber filaments is defined as the outermost fiber filaments, the C layer of fiber filaments is defined as the fiber filaments in contact with the weft 20', and the B layer of fiber filaments is defined as the fiber filaments between the A layer and the C layer. It can be understood that three layers of fiber filaments are taken as an example, but the number of layers of fiber filaments of the warp 10' and the weft 20' is not limited in the present application. The surface of the conductive cloth 101 facing the screen 200 presents a concave-convex form, especially at the weaving nodes between the warp 10' and the weft 20' (i.e., the position indicated by D1 in the figure), which is deeply concave, while the parts of the warp 10' and the weft 20' closest to the screen 200 (i.e., the positions indicated by D2 and D3 in the figure) are obviously convex, and it can be seen that the warp 10' is obviously higher than the weft 20'. Correspondingly, the corresponding position of A-A in the top view is shown in Fig. 5, D2 is more prominent than D1 and D3, and the area H where D2 is located is the higher part of the surface of the conductive cloth 101, which is the area framed by the dashed line in Fig. 5.

[0108] As can be seen, when the screen 200 is placed on the surface of the conductive cloth 101, the first part in contact with the surface of the screen 200 is D2 (the comparison here is only within the range shown in FIG. 4), at this time the effective contact area of the screen 200 with the conductive cloth 101 is the area of the region where D2 is located (the area of the H region). As the pressing force between the screen 200 and the conductive cloth 101 gradually increases, the surface of the screen 200 will be in contact with D2 and D3, at this time the effective contact area of the screen 200 with the conductive cloth 101 is the area of the region where D2 is located and the area of the region where D3 is located. When the pressing force between the screen 200 and the conductive cloth 101 continues to increase to a certain value, the surface of the screen 200 will be in contact with D1, D2 and D3, at this time the effective contact area of the screen 200 with the conductive cloth reaches the maximum, which is the area of the region where D1 is located, the area of the region where D2 is located and the area of the region where D3 is located. Similar rules exist in other regions in FIG. 5, for example, there are multiple higher regions H on the surface of the conductive cloth 101, which are represented by dashed lines in FIG. 5.

[0109] In this case, in order to achieve sufficient contact between the conductive cloth 101 and the screen 200, it is necessary to increase the pressing force on the conductive foam 100, so that the surface of the conductive cloth 101 is pressed by the screen 200 to present a flat shape, thereby increasing the effective contact area between the conductive cloth 101 and the screen 200. However, excessive pressing force will cause the screen 200 to appear to be imprinted. In order to avoid the screen 200 from being imprinted, the pressing force on the conductive foam 100 needs to be reduced, and the reduction of the pressing force will make the conductive cloth 101 and the screen 200 unable to be in sufficient contact. It is analyzed that under the condition of weak pressing force, only the warp 10' at D2 is the main contact part of the conductive cloth 101, and it is difficult for the weft 20' at D3 and the woven node at D1 to contact the screen 200. In the case that the conductive cloth 101 cannot fully contact the screen 200, the nonlinearity of the contact interface will become more obvious, and it will be more likely to generate third harmonic, passive intermodulation (PIM) and other frequency signals other than the main frequency. These other frequency signals are the main source of radiated spurious emission (RSE), and the RSE index is an important index for acceptance of electronic equipment products such as mobile phones. Therefore, the case that the conductive cloth 101 cannot fully contact the screen 200 will bring the risk that the radiated spurious emission test cannot be passed. The theoretical basis will be described in detail below.

[0110] According to the research theory, the key parameters affecting the third harmonic current value I of the conductive foam 100 are:

[0111] Wherein, k is the interface effective contact area fraction, F is the contact pressure, S is the size of the conductive foam, p is the resistivity, the third harmonic current value I is proportional to the above key parameters.

[0112] As described above, the main factors affecting the third harmonic current I include the contact pressure F and the effective contact area fraction k. The contact pressure F is the pressing force of the screen 200 on the conductive cloth 101 mentioned above, and the contact pressure F is negatively correlated with the third harmonic current I, that is, the greater the contact pressure F, the smaller the third harmonic current I, however, limited by the problem of screen 200 stamping, the pressing force of the screen 200 on the conductive cloth 101 cannot be too large, that is, the value of the contact pressure F is limited; the effective contact area fraction k is the contact degree of the screen 200 and the conductive cloth 101 mentioned above, the greater the effective contact area fraction k, the more sufficient the contact between the screen 200 and the conductive cloth 101, and the effective contact area fraction k is also negatively correlated with the third harmonic current I, that is, the greater the effective contact area fraction k, the smaller the third harmonic current I. Therefore, in order to weaken the third harmonic at the contact interface of the conductive foam 100 and the screen 200, it is necessary to ensure that the screen 200 and the conductive cloth 101 can be in sufficient contact.

[0113] In summary, the conductive cloth 101 in the related art has the problem that it cannot be in sufficient contact with the device to be connected under the condition of weak pressing force.

[0114] Therefore, in order to solve the above technical problems, the present application provides a conductive cloth, a conductive foam and an electronic device, which can improve the surface flatness of the conductive cloth by using a conductive material to compensate for the height difference of the cloth substrate, so that the surface of the conductive cloth can approach a plane under the condition of weak pressing force, thereby achieving sufficient contact with the device to be connected.

[0115] The electronic device provided by the embodiment of the present application can also be referred to as a mobile device, a terminal device, a mobile terminal or a terminal. The electronic device includes but is not limited to a handheld device, a vehicle-mounted device, a wearable device, a computing device or other processing devices connected to a wireless modem. For example, the electronic device can include a smart watch, a smart wristband, a smart phone, a personal digital assistant (PDA) computer, a tablet computer, a notebook computer, a vehicle-mounted computer, smart glasses, a game console and other electronic devices with the conductive foam 100 and requiring thin and light design.

[0116] For more convenient to elaborate the electronic device provided by the embodiments of the present application, as an example but not limited, the following will be in detail to elaborate the technical solutions of the present application with the electronic device is a smart phone. At the same time, in order to facilitate the description of each embodiment, for conductive foam 100, establish XYZ coordinate system. Specifically, the definition of the smart phone short side of the extension direction is X direction, the definition of the smart phone long side of the extension direction is Y direction, the definition of the smart phone thickness direction is Z direction, and the X direction, Y direction and Z direction are perpendicular to each other.

[0117] Continuing to refer to the smart phone provided by the embodiments of the present application shown in Figure 3, including screen 200, shell 300 and conductive foam 100 (not shown in Figure 3). Shell 300 includes middle frame 301 and battery cover 302. The front end surface of the middle frame 301 is fixedly provided with the screen 200, and the rear end surface of the middle frame 301 is fixedly provided with the battery cover 302. The screen 200, the middle frame 301 and the battery cover 302 jointly define the accommodation space of the smart phone, which is used to install various functional elements of the smart phone, such as the conductive foam 100, the camera module 600, the circuit board 400 and other functional elements mentioned below.

[0118] Optionally, the battery cover 302 can be covered on the middle frame 301 by screwing, clamping or the like. A sealing ring can be provided between the battery cover 302 and the middle frame 301 to improve the sealing and waterproof effect of the joint between the battery cover 302 and the middle frame 301. The sealing ring can be made of high elastic material such as silica gel or rubber.

[0119] In addition, the smart phone can also include: processor, universal serial bus (universal serial bus, USB) interface, charging management module, power management module, battery, microphone, mobile communication module, antenna, wireless communication module, audio module, earphone interface, sensor module, key and subscriber identification module (subscriber identification module, SIM) card interface and other functional elements.

[0120] These functional elements can be changed according to user needs. It can be understood that the specific embodiments introduced above are only one specific embodiment of the present application, and other ways that can realize the scheme of the present application are also the scope of protection of the present application, which is not described here.

[0121] Figure 6 is a sectional view of the partial device of T-T in Figure 3. It can be understood that Figure 6 only shows the relevant part of the device and its connection relationship.

[0122] As shown in FIG. 6, in the scenario of grounding the screen 200 of the smart phone, the inner side of the screen 200, i.e. the side of the screen 200 facing the inside of the phone, is connected with the conductive foam 100, and the side of the screen 200 facing the inside of the phone is also provided with the metal middle frame 301 at intervals, so that the conductive foam 100 is compressed between the screen 200 and the metal middle frame 301, thereby realizing the grounding of the screen 200. It can be understood that, in the scenario of using the conductive foam 100 to connect the screen 200 and the metal middle frame 301, as an example, the extension direction of the short side of the conductive foam 100 can be parallel to the above-mentioned X direction, the extension direction of the long side of the conductive foam 100 can be parallel to the above-mentioned Y direction, and the thickness direction of the conductive foam can be parallel to the above-mentioned Z direction.

[0123] Continuing to refer to FIG. 6, the circuit board 400 of the smart phone has various electronic components 401 such as resistors, capacitors, chips, etc., in order to shield the influence of external electromagnetic waves on the internal circuit and the external radiation of the internally generated electromagnetic waves, part of the electronic components 401 need to be covered with a shielding cover 500, and in the scenario of grounding the shielding cover 500, the metal middle frame 301, the conductive foam 100 and the shielding cover 500 are sequentially stacked, and the conductive foam 100 is compressed between the shielding cover 500 and the metal middle frame 301, thereby realizing the grounding of the shielding cover 500.

[0124] In addition to being used for the grounding of the screen 200 and the grounding of the shielding cover 500, the conductive foam 100 in the embodiments of the present application can also be used for electrical connection between other functional elements, for example, continuing to refer to FIG. 6, the antenna 700 is made on the battery cover 302 of the smart phone by laser direct structuring (LDS) technology or by a flexible circuit board, and the conductive foam 100 is arranged between the circuit board 400 and the battery cover 302, so that the antenna 700 on the circuit board 400 and the battery cover 302 is electrically connected through the conductive foam 100. Generally, two to four antennas 700 are needed for each signal frequency band, and each antenna 700 has two connection points to form a feed point, so two conductive foams 100 are needed for each antenna 700.

[0125] FIG. 7 is a sectional view of an example of the camera module 600 of the smart phone provided by the embodiments of the present application.

[0126] As shown in FIG. 7, in the scenario of grounding the camera module 600 of the smart phone, the side of the camera module 600 away from the lens is provided with a copper foil 602, a steel sheet support 601 is provided above the copper foil 602 at intervals, and the conductive foam 100 compressed and deformed is arranged in the gap between the copper foil 602 and the steel sheet support 601, and the end of the steel sheet support 601 is fixed on the power connection end of the circuit board 400 by a screw, thereby realizing the grounding of the camera module 600.

[0127] FIG. 8 is a cross-sectional view of another example of the camera module 600 of the smart phone according to an embodiment of the present application.

[0128] As shown in FIG. 8, in another scenario, due to the limited internal space of the smart phone, the gap between the camera module 600 and the steel bracket 601 can not be wide enough to provide sufficient layout space for the conductive foam 100, and in this case, only the conductive cloth 101 can be laid between the copper foil 602 and the steel bracket 601 to establish electrical connection between the copper foil 602 and the steel bracket 601, thereby achieving grounding of the camera module 600.

[0129] Similarly to the above scenario, in other scenarios, for example, in the grounding scenario of the screen 200, only the conductive cloth 101 can be used to achieve electrical connection between the screen 200 and the metal middle frame 301, thereby achieving grounding of the screen 200; for another example, in the grounding scenario of the shielding cover 500, only the conductive cloth 101 can be used to achieve electrical connection between the shielding cover 500 and the metal middle frame 301, thereby achieving grounding of the shielding cover 500; for another example, electrical connection between the circuit board 400 and the antenna 700, and electrical connection between other functional elements, can all be achieved only by using the conductive cloth 101.

[0130] In the above scenarios, the extrusion force between the conductive foam 100 and the device to be connected is usually weak, for example, 0.2N-0.4N. The device to be connected can be the screen 200, the metal middle frame 301, the circuit board 400, the battery cover 302, and the like.

[0131] FIG. 9 is a cross-sectional view of four embodiments of the conductive foam 100 according to an embodiment of the present application. In FIG. 9, (a) is a D-shaped conductive foam; (b) is an L-shaped conductive foam; (c) is a T-shaped conductive foam; and (d) is a P-shaped conductive foam.

[0132] As shown in FIG. 9, the present application provides a conductive foam 100, the cross section of which includes but is not limited to D-shaped, L-shaped, T-shaped, P-shaped, and the like. The conductive foam 100 includes the conductive cloth 101, the foam core 103, and the adhesive 102, and the conductive cloth 101 is adhered to the outside of the foam core 103 by the adhesive 102.

[0133] Optionally, the material of the foam core 103 includes but is not limited to foamed polyurethane, foamed polypropylene, foamed polyethylene, special rubber, ethylene-vinyl acetate copolymer (EVA), and ethylene-propylene-diene rubber.

[0134] Optionally, the adhesive 102 includes but is not limited to heat-set adhesive, pressure-sensitive adhesive, and light-sensitive adhesive.

[0135] Optionally, besides the D-shaped, L-shaped, T-shaped, P-shaped, the cross-sectional shape of the conductive foam 100 in the present application can also be triangular, circular, oval, polygonal and other irregular shaped structures.

[0136] FIG. 10 is a sectional view of another example of the conductive foam 100 provided in an embodiment of the present application.

[0137] As shown in FIG. 10, in one embodiment provided in the present application, the conductive foam 100 further comprises an insulating glue 104, which is arranged on the surface of the bubble core 103 and used to bond the bubble core 103 to the device to be connected.

[0138] In the present embodiment, the insulating glue 104 serves the purpose of bonding and fixing the conductive foam 100 as a whole to the component to be connected. In addition, the insulating glue 104 is mainly selected to improve the bonding strength. In the related art, the conductive foam 100 is usually bonded and fixed as a whole by using conductive glue. However, since the conductive glue is mainly composed of two parts, conductive particles (for conducting electricity) and glue (for bonding), while the insulating glue 104 only has glue, under the premise that the conductive glue and the insulating glue 104 are of the same weight, the insulating glue 104 contains more glue and thus has greater bonding strength.

[0139] Optionally, the insulating glue 104 can be arranged on the top of the bubble core 103; or the insulating glue 104 can be arranged on the bottom of the bubble core 103, for example, as shown in FIG. 10; or the insulating glue 104 can also be arranged on the side of the bubble core 103.

[0140] As shown in FIG. 10, in one embodiment provided in the present application, on the surface of the bubble core 103 with the insulating glue 104, the insulating glue 104 is located in the middle.

[0141] In the present embodiment, the insulating glue 104 is located in the middle of the side surface of the bubble core 103, which makes the conductive foam 100 as a whole bonded to the component at the middle part, so that the fixed constraint point of the conductive foam 100 is located in the middle and can remain stable, thereby improving the shock resistance of the conductive foam 100.

[0142] Of course, in other embodiments, the insulating glue 104 can also be arranged at the edge of the bubble core 103. For example, FIG. 11 is a sectional view of another example of the conductive foam 100 provided in an embodiment of the present application. As shown in FIG. 9, in one embodiment provided in the present application, on the surface of the bubble core 103 with the insulating glue 104, the insulating glue 104 is adjacent to the edge.

[0143] In the present embodiment, the insulating glue 104 is adjacent to the edge of the bubble core 103, so that the fixed constraint point of the conductive foam 100 is located at the edge, which can be used in some narrow and special installation scenarios.

[0144] As shown in FIG. 11, in an embodiment provided by the present application, the surface of the foam core 103 has an avoiding area 103a, and the avoiding area 103a is not provided with the conductive cloth 101.

[0145] In the embodiment, the surface of the foam has the avoiding area 103a which is not provided with the conductive cloth 101, so as to avoid the false connection to the non-grounded components, thereby facilitating the installation of the conductive foam 100. For example, if the installation space is narrow and the side of the installation site has a component which does not need to be grounded, the conductive foam 100 cannot avoid the component as a whole, and the avoiding area 103a can be used to stick to the component, thereby avoiding the false connection to the component.

[0146] FIG. 12 is a schematic diagram of the working principle of the conductive foam 100 in FIG. 10.

[0147] Taking the screen 200 of a smart phone as an example, as shown in FIG. 12, the components at the top and bottom of the conductive foam 100 are the screen 200 and the metal middle frame 301 respectively. After the screen 200 and the metal middle frame 301 deform and extrude the conductive foam 100, the conductive cloth 101 of the conductive foam 100 is tightly attached to the opposite surfaces of the screen 200 and the metal middle frame 301. Under the skin effect, the static electricity and interference current accumulated on the screen 200 flow to the metal middle frame 301 through the conductive cloth 101, and then the metal middle frame 301 conducts the current to the user's hand or the external environment, so as to reduce the influence of the static electricity and the interference current on the screen 200 and ensure the normal work of the screen 200.

[0148] FIG. 13 is a sectional view of another example of the conductive foam 100 provided by the embodiment of the present application.

[0149] As shown in FIG. 13, in an embodiment provided by the present application, the number of the conductive cloth 101 is two, and the two conductive cloths 101 are oppositely arranged on the surface of the foam core 103. The pores of the foam core 103 are filled with the conductive paste 30.

[0150] In the embodiment, since the foam core 103 does not have the conductive cloth 101 on the peripheral wall, the volume of the conductive foam 100 can be further reduced. Moreover, the pores of the foam core 103 are filled with the conductive paste 30, and the two conductive cloths 101 can be electrically connected when the conductive foam 100 is extruded, thereby ensuring that the conductive foam 100 can be electrically connected.

[0151] As mentioned above, the present application will focus on the new improvement scheme of the conductive cloth 101. The conductive cloth 101 provided by the embodiment of the present application will be described in detail in combination with the drawings. It can be understood that the conductive foam 100 described above is an example of the application scene of the conductive cloth 101 provided by the embodiment of the present application, and is not limited.

[0152] Taking the conductive cloth 101 between the conductive foam 100 and the screen 200 in FIG. 12 as an example. In this example, the direction of the screen 200 relative to the conductive foam 100 is defined as the positive direction of the Z-axis. In this example, "up" refers to the positive direction of the Z-axis, "down" refers to the negative direction of the Z-axis, "high" refers to the positive direction of the Z-axis, and "low" refers to the negative direction of the Z-axis, that is, along the positive direction of the Z-axis, gradually "up", gradually "high".

[0153] FIG. 14 is a top view of an example of the cloth substrate 1011 provided in an embodiment of the present application. FIG. 15 is an equivalent matrix diagram of FIG. 14. FIG. 16 is a cross-sectional view of an example of E-E in FIG. 14. FIG. 17 is a cross-sectional view of an example of M-M in FIG. 14.

[0154] As shown in FIGS. 14-17, in one embodiment provided in the present application, the cloth substrate 1011 has oppositely arranged third and fourth surfaces, and the surface of the cloth substrate 1011 facing the screen 200 is defined as the third surface, and the surface of the cloth substrate 1011 facing the bubble core 103 is defined as the fourth surface. It should be noted that, as known from the foregoing, the surface of the cloth substrate 1011 is not a flat plane, and the part of the cloth substrate 1011 exposed on the side close to the screen should be considered as part of the third surface, and the part of the cloth substrate 1011 exposed on the side close to the bubble core 103 should be considered as part of the fourth surface.

[0155] The cloth substrate 1011 is woven by interlacing a plurality of first strands 10 and a plurality of second strands 20. That is, the cloth substrate 1011 includes a plurality of first strands 10 arranged at intervals along a first direction, and a plurality of second strands 20 arranged at intervals along a second direction, the first direction being perpendicular to the second direction. Each of the plurality of first strands 10 is interlaced with the plurality of second strands 20, and each of the plurality of second strands 20 is interlaced with the plurality of first strands 10. As shown in FIG. 16, the second strand 2001 is one of the plurality of second strands 20, and the second strand 2001 is interlaced with the two adjacent first strands 1001 and 1002, that is, the second strand 2001 is above the first strand 1001 and below the first strand 1002, and so on. As shown in FIG. 17, the first strand 1001 is one of the plurality of first strands 10, and the first strand 1001 is interlaced with the two adjacent second strands 2001 and 2002, that is, the first strand 1001 is below the second strand 2001 and above the second strand 2002, and so on. For ease of description, the first direction can be the X-axis direction and the second direction can be the Y-axis direction.

[0156] In the present example, each first wire bundle 10 is a layer of first wire 11, and the first wire 11 includes a plurality of first fiber filaments 111. Each second wire bundle 20 is a layer of second wire 21, and the second wire 21 includes a plurality of second fiber filaments 211. Compared with the cloth base material composed of three layers of fiber filaments in the above, the cloth base material composed of one layer of fiber filaments in the first wire bundle 10 and the second wire bundle 20 can not only reduce the overall thickness of the conductive cloth 101, but also make the surface facing the screen 200 more planar. However, the number of layers of fiber filaments in the present embodiment is not limited to one, and can also be two, three or more.

[0157] As shown in FIGS. 14 and 15, the cloth base material 1011 includes a plurality of weaving units W, each of which is composed of a column bundle segment C woven on the second wire bundle 20 and a row bundle segment R woven on the first wire bundle 10. Among them, the column bundle segment woven on the second wire bundle means that the column bundle segment is woven on the side of the second wire bundle close to the screen 200, and similarly, the row bundle segment woven on the first wire bundle means that the row bundle segment is woven on the side of the first wire bundle close to the screen 200. The column bundle segment and the row bundle segment are connected, the column bundle segment is a segment of the first wire bundle 10, and the row bundle segment is a segment of the second wire bundle 20, such as the first row bundle segment R1 and the first column bundle segment C1 in FIG. 14, which are connected to form the first weaving unit W1, and the second row bundle segment R2 and the second column bundle segment C2 are connected to form the first weaving unit W2. Among them, connected means adjacent to each other, and from the perspective of the third surface, C1, C2, C3, and C4 are adjacent to R1. It can also be said that each weaving unit is composed of a connected first wire bundle segment and a second wire bundle segment, the first wire bundle segment can be a column bundle segment, and the second wire bundle segment can be a row bundle segment, and vice versa. The part of the column bundle segment of each weaving unit belonging to the third surface is the first surface, and the part of the row bundle segment belonging to the third surface is the second surface, and the first surface and the second surface have a height difference. Or, the first surface of the column bundle segment of each weaving unit facing the screen 200 has a height difference with the second surface of the row bundle segment facing the screen 200.

[0158] For ease of description, define each first wire bundle 10 as a column, and each second wire bundle 20 as a row. As shown in FIG. 15, the row and column of FIG. 14 can be equivalent to FIG. 15. The corner region refers to the region where the first row intersects the first column, the first row intersects the last column, the last row intersects the first column, and the last row intersects the last column, as shown in the grid block in FIG. 15. The edge region refers to the region where the first row, the last row, the first column, and the last column are located, except for the corner region, as shown in the diagonal block in FIG. 15. The middle region refers to the region other than the corner region and the edge region, as shown in the dot block in FIG. 15.

[0159] From the perspective of the row beam segments, the row beam segments can include a plurality of middle row beam segments, edge row beam segments, and corner row beam segments. As shown in FIG. 14, the middle row beam segments are the row beam segments located in the middle region. For example, the row beam segment R1 is a middle row beam segment, and the row beam segment R1 forms the weaving unit W1, the weaving unit W2, the weaving unit W3, and the weaving unit W4 with the column beam segment C1, the column beam segment C2, the column beam segment C3, and the column beam segment C4, respectively. The area enclosed by the dashed line in FIG. 14 is the area of the weaving unit W1, and the areas of the other weaving units W are the same as that of the weaving unit W1, which are not shown one by one. The edge row beam segments are the row beam segments located in the edge region. For example, the row beam segment R2 is an edge row beam segment, and the row beam segment R2 forms the weaving unit W5, the weaving unit W6, and the weaving unit W7 with the column beam segment C5, the column beam segment C6, and the column beam segment C7, respectively. The corner row beam segments are the row beam segments located in the corner region. For example, the row beam segment R3 is a corner row beam segment, and the row beam segment R3 forms the weaving unit W8 and the weaving unit W9 with the column beam segment C8 and the column beam segment C9, respectively. It can be understood that the above three types of row beam segments are not necessarily included on the weaving fabric substrate 1011 with a small number of weaving counts, that is, the number of the above three types of row beam segments can be any positive integer greater than or equal to 0. The division method from the perspective of the column beam segments is similar to that from the perspective of the row beam segments, which is not described herein again. The weaving units divided from the two perspectives are consistent. It should be noted that when the number of row beam segments is counted from the perspective of the row beam segments, the row beam segment and a plurality of column beam segments around the row beam segment form a weaving unit, which means that although the row beam segment is not counted repeatedly, there is a common column beam segment between two adjacent row beam segments, which forms two different weaving units with the two row beam segments, respectively. Therefore, the column beam segment is counted repeatedly in adjacent weaving units. This can be understood as follows: in order to make the surface relatively flat, it is necessary to compare each adjacent row beam segment and column beam segment, so the column beam segment is counted into the weaving units of the adjacent row beam segments multiple times. When the number of column beam segments is counted from the perspective of the column beam segments, the situation is opposite, which is not described herein again.

[0160] The conductive material 1012 is covered on the surface of the fabric substrate 1011 facing the screen 200, that is, the third surface. The conductive material 1012 is a material with conductive properties and can conduct current under certain conditions. The conductive material 1012 can be a metal such as gold, nickel, copper, or a combination of multiple metals, or a conductive paste, or a combination of a metal and a conductive paste, etc. The conductive material 1012 covers the third surface so that the conductive fabric 101 has conductive properties. It can be understood that the conductive material 1012 can completely or partially cover the third surface.

[0161] The conductive material 1012 is configured to have a thickness difference between the conductive material 1012 covering the first surface of the weaving unit W and the conductive material 1012 covering the second surface of the same weaving unit W.

[0162] The plurality of weaving units includes at least a plurality of effective weaving units, and a ratio of a number of the effective weaving units to a number of the weaving units is greater than or equal to 50%.

[0163] As to the number of the weaving units, the angle of the row wire bundle segment is taken as an example here, and the angle of the column wire bundle segment is not described again because the number of the weaving units calculated by the two angles is consistent. It is assumed that the cloth base material 1011 includes L first row wire bundle segments, M second row wire bundle segments, and N third row wire bundle segments. The first row wire bundle segment is located in the middle area (the first row wire bundle segment can be the middle row wire bundle segment in the foregoing), the second row wire bundle segment is located in the edge area (the second row wire bundle segment can be the edge row wire bundle segment in the foregoing), and the third row wire bundle segment is located in the corner area (the third row wire bundle segment can be the corner row wire bundle segment in the foregoing), and L, M, and N are positive integers greater than or equal to 0. As known from the foregoing example, the middle row wire bundle segment can form four weaving units together with the surrounding column wire bundle segments, the edge row wire bundle segment can form three weaving units together with the surrounding column wire bundle segments, and the corner row wire bundle segment can form two weaving units together with the surrounding column wire bundle segments. Therefore, the number X of the weaving units of the cloth base material 1011 is L*4+M*3+N*2.

[0164] Taking the cloth base material 1011 in FIG. 14 as an example, the cloth base material 1011 is woven by 8 first wire bundles 10 and 4 second wire bundles 20 crossing each other, and the cloth base material 1011 includes 8 columns and 4 rows, and L=6, M=8, and N=2. Therefore, the number X of the weaving units W of the cloth base material 1011 is 6*4+8*3+2*2=52.

[0165] As known from FIGS. 16 and 17, the weaving unit W has a fluctuation height difference, and the height difference exists between the second surface and the first surface of the weaving unit W, and the surfaces do not tend to be horizontal (see the dashed horizontal line in the figures). That is, the higher part and the lower part of the weaving unit W have a height difference, causing the surface to be uneven. When the conductive material 1012 is covered on the weaving unit W, the overall height of each area of the conductive cloth 101 is the sum of the height of the cloth base material 1011 in the area and the thickness of the conductive material 1012. Whether the surface of the conductive cloth 101 facing the screen 200 tends to be flat depends on whether the overall height of each area of the conductive cloth 101 tends to be consistent. In the conductive cloth 101, the fluctuation height difference of the weaving unit W can be compensated by covering the conductive material 1012 with different thicknesses in different areas. For ease of description, this type of weaving unit W is referred to as an effective weaving unit W in this application. 有效For example, the conductive material 1012 is covered with a thinner layer at the upper part of the effective weaving unit W, and covered with a thicker layer at the lower part of the effective weaving unit W, so that the surface of the conductive cloth 101 tends to be flat in the area of the effective weaving unit W. It should be understood that the effective weaving unit is only a name for convenience of description and does not constitute any limitation. The effective weaving unit will be described in detail below.

[0166] In an embodiment provided by the present application, the effective weaving unit W 有效 is configured such that, when the conductive cloth 101 is subjected to a pressure of 0.2 N to 0.4 N, the surface of the conductive material 1012 covered on the effective first surface tends to be horizontal with the surface of the conductive material 1012 covered on the effective second surface.

[0167] FIG. 18 is a cross-sectional view of an example of the conductive cloth 101 connected to the screen 200 according to an embodiment of the present application. Taking the effective weaving unit W 有效 in FIG. 18 as an example, the effective weaving unit W 有效 includes an effective first surface and an effective second surface, the first surface of the effective weaving unit W 有效 is the effective first surface, and the second surface of the effective weaving unit W 有效The second surface of the conductive cloth 101 is an effective second surface. The conductive material 1012 covers the effective first surface and the effective second surface. In the corresponding area of the woven unit on the base material 1011, the effective first surface includes a first area S1, and the effective second surface includes a second area S2. When the conductive cloth 101 is applied with a weak extrusion force (such as F in FIG. 18) of 0.2 N to 0.4 N, the difference between the height H1 of the first area S1 and the height H2 of the second area S2 is a first value h1 = ±(H1-H2) (height difference), the difference between the thickness T1 of the conductive material 1012 covering the first area S1 and the thickness T2 of the conductive material 1012 covering the second area S2 is a second value h2 = ±(T1-T2) (thickness difference), and the difference between the first value and the second value is a third value h3 = ±(h1-h2). The third value h3 is less than or equal to a first threshold value, so that the surface of the conductive cloth 101 in the first area and the surface of the conductive cloth 101 in the second area tend to be level. For example, the first threshold value can be 5 μm, 3 μm, 0.5 μm, 0 μm, etc. The first threshold value also takes into account that it can be difficult to achieve a complete consistency between the thickness difference and the height difference due to the error of the manufacturing process, and allows a certain error between the two. Of course, the most ideal case is that the first value is equal to the second value, that is, the third value is equal to 0, which means that the overall height of the conductive cloth 101 in the first area is equal to the overall height of the conductive cloth 101 in the second area, and finally the surface of the conductive cloth 101 in the first area and the surface of the conductive cloth 101 in the second area are at the same level. Among them, the above difference values are the difference values when the conductive cloth 101 is applied with a weak extrusion force of 0.2 N to 0.4 N. When the extrusion force applied to the conductive cloth 101 is within the range of 0.2 N to 0.4 N, it can be considered as the weak extrusion force mentioned above. Of course, the range includes both end values. It can be understood that when the conductive cloth 101 is applied in a scene, the greater the extrusion force applied, the higher the error tolerance of the difference value, and the first threshold value can also be smaller accordingly. In addition, the first area S1 and the first area S2 can approach a point infinitely. The first area S1 can be a first position of the effective first surface, or a first position and a surrounding area thereof. The second area S2 can be a second position of the effective second surface, or a second position and a surrounding area thereof. That is, the first value is the difference between the two areas. By covering the conductive material 1012 with different thicknesses in different areas with height differences, the original undulating height difference of the base material 1011 is compensated, and the flatness of the conductive cloth 101 is improved, so that the conductive cloth 101 can also be in full contact with the device under the condition of weak extrusion force.

[0168] It should be noted that the thickness direction and the height direction in the embodiments of the present application can be along the Z-axis direction, the thickness of the conductive material 1012 at a certain position can be the distance from the lowest point to the highest point of the conductive material at the position; the height of the cloth substrate 1011 or the conductive cloth 101 at a certain position can be the distance from the highest point of the cloth substrate 1011 or the conductive cloth 101 at the position to the reference plane, for example, the reference plane can be the plane where the surface of the bubble core 103 faces the conductive cloth 101, as long as the reference plane for comparing the height difference remains consistent. The height and thickness of a certain area mentioned in the embodiments of the present application can be measured by the multi-point measurement method, and a value is obtained by a certain calculation method to represent the height or thickness of the area. For example, 3 points can be taken, and if the area is very small, only 1 point can be taken, and the number of measurement points is not limited. For example, the average value of multiple values can be taken, and the calculation method is not limited. The height difference between the first surface and the second surface can also be compared by randomly taking multiple sample values in the regions of the two surfaces. Alternatively, when the areas of the first surface and the second surface are very small, the height difference between the first surface and the second surface can be approximately the height difference between the first region and the second region, or the height difference between the first position and the second position. The thickness difference between the conductive material covering the first surface and the conductive material covering the second surface is the same, and details are not repeated here.

[0169] Generally, whether the surface of the conductive material 1012 covering the effective first surface and the surface of the conductive material 1012 covering the effective second surface tend to be horizontal or not can also be compared by randomly taking multiple sample values on the effective second surface and the effective first surface respectively, if multiple places satisfy the condition of "the third value h3 is less than or equal to the first threshold value", it can be considered that the two surfaces tend to be horizontal. Alternatively, when the areas of the second surface and the first surface are very small, it can be approximately compared between two positions in the two regions, if the two positions satisfy the condition of "the third value h3 is less than or equal to the first threshold value", it can be considered that the two surfaces tend to be horizontal.

[0170] In order to further improve the flatness of the effective weaving unit surface (the effective weaving unit surface includes the effective second surface and the effective first surface), assuming that the highest point of the effective weaving unit surface is on the effective first surface and the lowest point of the effective weaving unit surface is on the effective second surface, the first area S1 can be the highest point of the effective first surface or the highest point and the surrounding area of the highest point (the area can be referred to as a peak), and the second area S2 can be the lowest point of the effective second surface or the lowest point and the surrounding area of the lowest point (the area can be referred to as a valley). Assuming that the highest point of the effective weaving unit surface is on the effective second surface, the first area S1 can be the lowest point of the effective first surface or the lowest point and the surrounding area of the lowest point (the area can be referred to as a valley), and the second area S2 can be the highest point of the effective second surface or the highest point and the surrounding area of the highest point (the area can be referred to as a peak). That is, the first value is the height difference between the peak and the valley, and the second value is the thickness difference between the conductive material 1012 covering the peak and the valley, and at this time, the conductive material 1012 covering the valley is the thickest, and the conductive material 1012 covering the peak is the thinnest. By covering the conductive material 1012 with different thicknesses on the peak and the valley, the original relief height difference of the base fabric 1011 itself is compensated, and the surface flatness of the conductive cloth 101 is improved, so that the conductive cloth 101 can also be in full contact with the device under the condition of weak extrusion force. It can be understood that the comparison range of the "highest point" and the "lowest point" here is within the effective weaving unit.

[0171] Taking the base fabric 1011 in FIG. 14 as an example, the base fabric 1011 is covered with the conductive material 1012 to form the conductive cloth 101, when the extrusion force applied to the conductive cloth 101 is in the range of 0.2N-0.4N, the effective weaving unit W 有效 The number of the effective weaving unit W 有效 The ratio of the number of the effective weaving unit W 有效 to the number of the weaving unit W is 87%. Generally, when the ratio of the number of the effective weaving unit W

[0172] It should be noted that in the embodiments of the present application, the first bundle 10 can be the warp, and the second bundle 20 corresponds to the weft; the first bundle 10 can be the weft, and the second bundle 20 corresponds to the warp.

[0173] Further, still taking the conductive cloth 101 between the conductive foam 100 and the screen 200 in the screen grounding scenario as an example, FIG. 19 is a top view of the screen 200 grounded through the conductive foam 100, and FIG. 20 is a top view of the screen 200 from the inner side of the screen 200. FIG. 20 is a cross-sectional view of an example of U-U in FIG. 19, and the foam core 103 and the conductive material 1012 are omitted in FIG. 20.

[0174] Hereinafter, the contact area of the conductive cloth 101 and the screen 200 will be calculated and analyzed in detail by taking the conductive cloth 101 shown in FIG. 20 as an example. First, the following terms will be explained: nominal contact area, also known as surface contact area or geometric contact area, which is the area determined by the boundary of the macroscopic interface of two contact objects; and real contact area, also known as effective contact area or actual contact area, which is the sum of the areas of the micro contact surfaces generated by the direct transmission of the interface interaction force between two contact objects through the micro convex bodies and the deformation thereof.

[0175] Continuing to refer to FIG. 20, the nominal contact area of the conductive cloth 101 and the screen 200 is S, and the effective contact area of the conductive cloth 101 and the screen 200 is the sum of the contact areas of the surfaces of the conductive material 1012 on each first fiber filament 111 and the screen 200, plus the sum of the contact areas of the surfaces of the conductive material 1012 on each second fiber filament 211 and the screen 200, i.e., s1+s2+s3+s4+s5+s6+s7.

[0176] It can be understood that FIG. 20 only shows a partial area of the conductive cloth, and the effective contact area and the nominal contact area of the entire conductive cloth are analogously derived.

[0177] After the conductive cloth 101 and the screen 200 are in contact with each other, the ratio of the effective contact area to the nominal contact area, or the effective contact area fraction, is (s1+s2+s3+s4+s5+s6+s7) / S. The effective contact area fraction is an important indicator for measuring whether the conductive cloth 101 and the screen 200 are in sufficient contact. When the effective contact area fraction is greater than or equal to 50%, the two objects are in sufficient contact, the grounding requirement can be met, and the risk of RSE testing can be avoided. In an embodiment provided by the present application, when the effective contact area fraction of the conductive cloth is greater than or equal to 50%, it is considered that the surface of the conductive cloth tends to be horizontal.

[0178] In yet another embodiment provided in the present application, the conductive cloth 101 is configured such that, when the conductive cloth 101 is applied with a pressure of 0.2N-0.4N, the effective contact area ratio of the conductive cloth 101 to the device to be connected is greater than or equal to 50%. The device to be connected can be the screen 200. The nominal contact area of the conductive cloth 101 to the device to be connected is the sum of S of each region (each region is not overlapped), the effective contact area of the conductive cloth 101 to the device to be connected is the sum of (s1+s2+s3+s4+s5+s6+s7), and thus the effective contact area ratio of the conductive cloth 101 to the device is (s1+s2+s3+s4+s5+s6+s7) / S. In the related art, when the screen 200 applies a pressure of 0.5N to the conductive cloth 101, the effective contact area ratio of the conductive cloth 101 to the screen 200 is 40%-50%; and when the screen 200 applies a pressure of about 0.3N to the conductive cloth 101, the effective contact area ratio of the conductive cloth 101 to the screen 200 reaches 65% in the embodiment of the present application.

[0179] In addition, the nominal contact area is further explained. With reference to FIGS. 19-20, the device to be connected is taken as the screen 200, for example. When the area of the screen 200 is greater than or equal to the conductive cloth 101, the area of the conductive cloth 101 is taken as the nominal contact area, which can be approximately the area of the third surface in FIG. 14 without considering the conductive material. FIG. 21 is a top view of the circuit board 400 grounded by the conductive foam 100 according to an embodiment of the present application, in which the conductive foam 100 in FIG. 21 appears slightly transparent in vision, which is for the purpose of contrasting the area difference between the ground pad 402 and the conductive foam 100, and in fact, the conductive foam 100 is not transparent. FIG. 22 is a sectional view of V-V in FIG. 21, in which the foam core 103 and the conductive material 1012 are omitted in FIG. 22. As shown in FIGS. 21-22, the device to be connected is taken as the ground pad 402, for example. When the area of the ground pad 402 is less than the conductive cloth 101, the area of the ground pad 402 is taken as the nominal contact area, i.e., the area of the ground pad 402 in FIG. 21.

[0180] In summary, the conductive cloth 101 provided by the embodiment of the present application can compensate for the height difference caused by the undulation of the weaving unit of the cloth substrate 1011 by covering the weaving unit surface of the cloth substrate 1011 with conductive material 1012 of different thicknesses, thereby improving the effective contact area fraction between the conductive cloth 101 and the device under the same extrusion force. From a microscopic perspective, there is undulation between the row beam segments and the column beam segments of the weaving unit, resulting in a height difference between the second surface and the first surface. If the thickness of the conductive material 1012 remains substantially constant, the surface of the conductive material 1012 covering the surface of the weaving unit still has a height difference between the second surface and the first surface, which reduces the effective contact area fraction between the surface of the conductive material 1012 on the surface of the weaving unit and the device. In general, only a part of the highest area of the surface can be in contact with the surface of the device under weak extrusion force. When the thickness of the conductive material 1012 is thicker at the lower part of the weaving unit surface and thinner at the higher part of the weaving unit surface, the height difference between the second surface and the first surface is compensated for, so that the effective area fraction between the surface of the conductive material 1012 and the device is greater than or equal to 50%. When the number of weaving units that satisfy this condition, i.e., the number of effective weaving units, is further increased, for example, the ratio of the number of effective weaving units to the number of weaving units is greater than or equal to 50%, the conductive cloth 101 has more contact area with the device to be connected, that is, the conductive cloth 101 can fully contact the device under weak extrusion force, thereby increasing the conductive path between the conductive cloth 101 and the device. When the conductive cloth 101 is applied to the screen 200 grounding scheme, the screen 200 mold printing can be avoided, and the generation of third harmonic waves is also weakened or even avoided, thereby ensuring the smooth passing of the radiation spurious test of the electronic equipment.

[0181] Through simulation tests, under the same weak extrusion force, for example, 0.5N extrusion force is applied to the conductive cloth 101, the effective contact area fraction between the conductive cloth 101 in the embodiment of the present application and the device to be connected can reach more than 70%, while the effective contact area fraction between the conductive cloth 101 in the related art and the device to be connected is only 40%-50%. Compared with the related art, the conductive cloth 101 in the embodiment of the present application can reduce the third harmonic current by 20%-30%. If the same effective contact area fraction is achieved as a premise, the conductive cloth 101 in the embodiment of the present application can reduce the extrusion force by 40%-50%, which can effectively avoid the screen 200 mold printing problem in the screen 200 grounding scenario. If the same extrusion force and the same third harmonic current are achieved as a premise, the nominal contact area of the conductive cloth 101 in the embodiment of the present application can be reduced by 40%-50%, that is, the size of the conductive cloth 101 required is reduced, and in addition, the amount of adhesive 102 required by the small-size conductive cloth 101 is also reduced, so that the volume and weight of the conductive foam 100 formed finally are reduced.

[0182] The following will provide various specific examples for illustration.

[0183] FIGS. 23-27 are schematic diagrams of various embodiments of the conductive cloth 101 provided in the present application. The cloth substrate 1011 in the following embodiments can be any of the cloth substrates 1011 mentioned above, or any other cloth substrate having the function of a cloth substrate, and the type of the cloth substrate 1011 is not limited herein.

[0184] Please refer back to FIG. 10. The conductive foam 100 includes the conductive cloth 101, the foam core 103, and the adhesive 102, and the conductive cloth 101 is adhered to the outside of the foam core 103 by the adhesive 102. The conductive foam 100 further includes the insulating glue 104, which is arranged on the surface of the foam core 103 and used to adhere the foam core 103 to the component to be connected. Various cross-sectional views of the conductive cloth 101 along the thickness direction are shown in FIGS. 23-27. It should be noted that FIGS. 23-27 are schematic diagrams, and the proportional relationship of each part in the diagrams is only for the convenience of description and does not constitute any special limitation.

[0185] As shown in FIG. 23, in the related art, the conductive cloth 101 includes the cloth substrate 1011 and the conductive material 1012’. The thickness of the conductive material 1012’ is usually 5-7.5 μm, and the present example takes 5 μm as an example. Since the surface of the cloth substrate 1011 is uneven and has pores, and the thickness of the conductive material itself is relatively thin, it is difficult to make the difference between the thicknesses of the conductive materials in different regions greater than a certain threshold value, so the thickness of the conductive material 1012’ covering each region on the surface of the weaving unit is basically uniform. This makes the surface of the conductive material 1012’ in the present example basically consistent with the unevenness of the cloth substrate 1011. According to the microscope observation, the height difference between the highest point and the lowest point of the conductive cloth 101 in the present example is about 10 μm, and the unevenness is concentrated between the weaving unit peaks and the weaving unit valleys of each weaving unit.

[0186] Fig. 24 is an embodiment provided by the present application. In the example, the conductive material 1012 includes a metal plating layer. The thickness of the conductive material 1012 is increased to ensure that the difference in thickness of the conductive material between different regions is greater than or equal to a threshold value, so as to compensate for the height difference between the first region S1 of the first surface and the second region S2 of the second surface of the woven unit. In this way, the ups and downs of the surface of the conductive cloth 101 are improved, and the effective contact area between the conductive cloth 101 and the device is increased, so that the harmonic current generated by the conductive foam under the same working pressure is reduced, that is, the working pressure of the foam can be reduced under the premise of keeping the harmonic level unchanged. Experimental data show that as the thickness of the conductive material 1012 itself increases, the proportion of effective woven units that can be compensated for the height difference gradually increases, and the effective contact area k also increases significantly. Therefore, under the condition that other conditions remain unchanged, increasing the thickness of the conductive material 1012 itself can improve the probability of compensating for the ups and downs of the height of the cloth substrate 1011 itself.

[0187] Specifically, in the embodiments provided by the present application, the thickness of the conductive material 1012 is greater than or equal to 10 μm, such as 12 μm. It should be noted that the thickness of the conductive material 1012 can also be measured by the multi-point measurement method mentioned above, such as randomly selecting three points to measure the thickness. If the thickness of the three points is greater than or equal to 10 μm, it is considered that the thickness of the conductive material 1012 is greater than or equal to 10 μm. The conductive material 1012 can include a copper layer, a nickel layer, and a gold layer, which are stacked in the thickness direction of the conductive cloth 101. The copper layer is a stack (or plating layer) composed of metal copper, the nickel layer is a stack (or plating layer) composed of metal nickel, and the gold layer is a stack (or plating layer) composed of metal gold. The sum of the thicknesses of the copper layer, the nickel layer, and the silver layer is greater than or equal to 10 μm. Since gold is more expensive than copper and nickel, the thickness of the copper layer and the nickel layer is usually greater than that of the gold layer. For example, the sum of the thicknesses of the copper layer and the nickel layer can be set to 9.5 μm, and the gold layer can be set to 0.3-1 μm. The gold layer can also be replaced by a silver layer, that is, a stack (or plating layer) composed of metal silver. Since the thickened metal plating layer improves the ups and downs of the surface of the conductive cloth 101, the part of the conductive foam in Fig. 24 that contacts the device to be connected is almost all gold or silver, which can fully utilize the good performance of gold or silver.

[0188] For example, when the 5 μm conductive material 1012' in the conductive foam 100 of FIG. 23 is replaced by the 10 μm conductive material 1012 of FIG. 24, the harmonic current becomes 63% of the original under the same conditions of the extrusion force and other conditions. In another aspect, under the premise of ensuring that the harmonic level does not deteriorate, by replacing the 5 μm conductive material 1012' in the conductive foam 100 of FIG. 23 with the 10 μm conductive material 1012 of FIG. 24, the extrusion force can be reduced by at least 50%. That is, the application scenario of weaker extrusion force can be adapted and good harmonic level can be ensured.

[0189] Similarly, for example, when the 5 μm conductive material 1012' in the conductive foam 100 of FIG. 23 is replaced by the 10 μm conductive material 1012 of FIG. 24, the harmonic current becomes 52% of the original under the same conditions of the extrusion force and other conditions. In another aspect, under the premise of ensuring that the harmonic level does not deteriorate, by replacing the 5 μm conductive material 1012' in the conductive foam 100 of FIG. 23 with the 10 μm conductive material 1012 of FIG. 24, the extrusion force can be reduced by at least 40%. That is, the application scenario of weaker extrusion force can be adapted and good harmonic level can be ensured. Under the same conditions, the PIM performance of silver is better than that of gold as a whole.

[0190] As an example, the conductive cloth 101 composed of the cloth base material 1011 and the metal plating layer can be generally made by electroplating or chemical plating, and the thickness of the metal plating layer is controlled to be greater than or equal to 10 μm during the manufacturing process to ensure that at least 50% of the weaving units can be compensated for the height difference by the thickness of the metal plating layer to increase the effective contact area between the surface of the conductive cloth 101 and the surface of the device to be connected.

[0191] It can be understood that the present application does not limit the manufacturing process. Moreover, the thickness of the metal plating layer is greater than or equal to 10 μm only as an example. For the cloth base material 1011 commonly used in the market, the height difference between the highest point and the lowest point is usually less than 10 μm, so setting the thickness of the metal plating layer to be greater than or equal to 10 μm can compensate for the height difference in most areas with a high probability. Of course, if another cloth base material 1011 has a large fluctuation due to the weaving process, the height difference between the highest point and the lowest point is further improved, and the thickness of the metal plating layer can be further increased, such as greater than or equal to 12 μm.

[0192] Figure 25 is another embodiment provided by the present application, in this example, the conductive material 1012 comprises a conductive paste. The conductive paste is a viscous paste composed of fine particles of high-purity metal, a binder, a solvent, and an auxiliary agent, and the mass ratio of the metal particles is usually more than 60%. The conductive foam can comprise a conductive cloth 101, a foam core 103, and an adhesive 102. The third surface of the cloth substrate 1011 of the conductive cloth 101 is covered with conductive paste. Since the conductive paste is in a liquid state during the coating process, the conductive paste will flow on the third surface of the cloth substrate 1011 before it solidifies. Based on the leveling effect of the liquid, the conductive paste will form the first region S1 and the second region S2 with different thicknesses mentioned above, so that the surface area of the conductive paste tends to be horizontal, thereby compensating for the height difference of the cloth substrate 1011 itself, improving the ups and downs of the surface of the conductive cloth 101, and thereby increasing the effective contact area between the conductive cloth 101 and the device. Therefore, the harmonic current generated by the conductive cloth 101 under the same working pressure is smaller, that is, the working pressure of the conductive cloth 101 can be reduced under the premise of keeping the harmonic level unchanged.

[0193] The conductive paste can be processed by coating, and the processing method is not limited. In addition, the third surface of the cloth substrate 1011 can also be covered with a metal plating layer, and the conductive paste is covered on the metal plating layer, that is, whether there is a metal plating layer between the cloth substrate 1011 and the conductive paste is not limited. The thickness of the conductive paste can be greater than or equal to 10 μm. It should be noted that the thickness of the conductive paste refers to the thickness of the conductive paste after solidification.

[0194] Compared with the metal plating scheme of FIG. 24, the conductive paste scheme utilizes the liquid state of the conductive paste before curing during processing, thereby improving the probability of forming an effective braided unit. During processing, because the conductive paste is in a liquid state, on the cloth base material 1011, for one braided unit, the conductive paste tends to flow from a higher place to a lower place, and finally tends to be leveled, thereby compensating for the height difference. Referring to FIG. 26, in an embodiment provided in the present application, each first strand 10 is a layer of first wire 11, and the first wire 11 includes a plurality of first fiber filaments 111 that are not twisted with each other. Each second strand 20 is a layer of second wire 21, and the second wire 21 includes a plurality of second fiber filaments 211 that are not twisted with each other. After the first strand 10 and the second strand 20 are braided into the conductive cloth 101, the conductive paste is coated on the surface of the conductive cloth 101. In the embodiment, the conductive paste is coated on the surface of the conductive cloth 101, which can fill the gaps between the fiber filaments by the conductive paste, and can also fill the pits at the braided nodes of the first strand 10 and the second strand 20, so that the surface of the conductive cloth 101 is closer to a plane, and the conductive cloth 101 can better fit the device to be connected, and further enables the conductive cloth 101 to maintain sufficient contact with the device to be connected, so as to meet the use requirements of the conductive foam 100 under weak extrusion force; in addition, the first strand 10 and the second strand 20 formed by a layer of fiber filaments reduce the thickness of the conductive cloth 101 to the extreme, and on this basis, the conductive paste is coated, thereby increasing the conductive path.

[0195] In an embodiment provided in the present application, the material of the conductive paste includes at least one of conductive silver paste, conductive copper paste, conductive nickel paste, and conductive graphene paste.

[0196] The conductive paste is a mixture of conductive substances suspended or dispersed in a liquid medium, commonly used for manufacturing electronic components 401 and circuit boards 400. It is mainly composed of two components: conductive particles and medium. The conductive particles are usually silver, copper, aluminum and other metal materials, which have very high electrical conductivity and mechanical strength. The difference between the conductive silver paste, the conductive copper paste, the conductive nickel paste and the conductive graphene paste lies in the different conductive particles, and the medium can all be organic matter.

[0197] In addition, a dispersant can also be added to the conductive paste. The dispersant refers to a substance added to the medium to improve the affinity between the particle surface and the medium, so that the particles can be easily infiltrated and remain in a dispersed state in the medium; or a substance that can produce steric hindrance to form a complete covering layer on the surface of the particles, thereby preventing the particles from agglomerating. In the present application, the dispersant can effectively improve the wettability, suspension stability and rheological properties of the conductive particles, prevent agglomeration and precipitation, uniformly disperse the conductive particles, and make the conductive paste have a suitable viscosity.

[0198] Optionally, the dispersant includes, but is not limited to, aqueous borate, sodium polyacrylate, glycerol, polyethylene glycol, triethanolamine, sodium hexametaphosphate, etc.

[0199] For example, when the conductive material 1012' in the conductive foam 100 of FIG. 23 is replaced by the conductive paste of FIG. 25, under the same extrusion force and other conditions, the harmonic current becomes 78% of the original. In other words, under the premise of ensuring that the harmonic level does not deteriorate, by replacing the conductive material 1012' in the conductive foam 100 of FIG. 23 with the conductive paste of FIG. 25, the extrusion force can be reduced by at least 65%.

[0200] FIG. 27 is another embodiment provided by the present application. In this example, the adhesive 102 in FIG. 23 is replaced by a conductive paste. Since the conductive paste contains adhesives and other substances, it has a certain viscosity and can be used as an adhesive. When the conductive paste is used as an adhesive, the conductive paste can seep out of the pores of the cloth substrate 1011. Since the liquid has fluidity, the seeped conductive paste will flow to the surrounding of the pores. Based on the leveling effect, the height difference between the first area S1 and the second area S2 is compensated, thereby improving the ups and downs of the surface of the conductive cloth 101, and further improving the effective contact area between the conductive cloth 101 and the device. Thus, under the same working pressure, the harmonic current generated by the conductive foam is smaller, that is, the working pressure of the foam can be reduced under the premise of ensuring that the harmonic level does not change. As shown in FIG. 26, a part of the conductive paste is between the bubble core 103 and the cloth substrate 1011, and a part of the conductive paste seeping out of the pores is on the third surface of the cloth substrate 1011, forming the conductive material 1012.

[0201] In this example, the conductive paste can also provide viscosity, so that the bubble core 103 and the conductive cloth 101 are adhered together, saving the adhesive. This means that the amount of conductive paste that seeps out due to the extrusion of the conductive cloth is reasonably utilized as the adhesive. Compared with the adhesive that only has adhesion performance but does not have conductive performance, this way saves the amount and operation steps. That is, in this embodiment, the seeped conductive paste not only fills the gaps between the fiber filaments, but also has the effect of bonding adjacent fiber filaments, so as to improve the connection reliability of the fiber filaments and avoid the disconnection between the fiber filaments, thereby avoiding the current circuit breaking. In this example, the conductive paste replaces the adhesive 102, reducing the overall thickness of the conductive foam 100.

[0202] Still taking the example that the conductive paste includes the conductive silver paste, when the conductive material 1012' in the conductive foam 100 of FIG. 23 is replaced by the conductive paste of FIG. 27, the harmonic current becomes 57% of the original under the same extrusion force and other conditions. In another aspect, under the premise of ensuring that the harmonic level does not deteriorate, by replacing the conductive material 1012' in the conductive foam 100 of FIG. 23 with the conductive paste of FIG. 27, the extrusion force can be reduced by at least 45%.

[0203] It can be understood that the conductive paste seeping out of the pores is mainly used for filling, and the surface of the cloth substrate 1011 can be coated with a metal plating layer. When the amount of seeping conductive paste is small, the surface of the conductive cloth 101 can be partially a metal plating layer and partially a conductive paste. As an example, a layer of conductive paste can be coated on the bubble core 103, and the metal-plated conductive cloth 101' is wrapped before the conductive paste is solidified. The conductive paste will seep out of the pores of the conductive cloth, thereby increasing the effective contact area of the conductive cloth 101 with the device to be connected. Optionally, the conductive paste overflowing the surface of the conductive cloth can be scraped off with a scraper to further improve the flatness of the surface of the conductive cloth 101.

[0204] It should be noted that the above various embodiments can also be combined for implementation. For example, the conductive foam 100 provided in the embodiments of the present application has a metal plating layer on the cloth substrate 1011, and the thickness of the metal plating layer is greater than or equal to 10 μm. A layer of conductive silver paste is further coated on the metal plating layer. Further, the adhesive of the conductive foam 100 is conductive silver paste, and the conductive silver paste seeps out to form a conductive material or part of a conductive material.

[0205] Further, the conductive cloth 101 in the above embodiments can be applied only to one or more surfaces of the conductive foam 100. Taking the example of a cuboid conductive foam 100, which includes six surfaces, the conductive cloth 101 provided in the embodiments of the present application is mainly used to improve the connection performance between the upper and lower interfaces of the conductive foam 100 and the device. It can be applied only to the interface without insulating glue, or only to part of a surface, which is not limited herein.

[0206] In addition, the first wire bundle 10 and the second wire bundle 20 of the conductive cloth 101 in the related art are usually composed of three or more layers of fiber layers, so that the conductive cloth 101 presents a concave-convex shape, further increasing the area and the height difference value of the second surface and the first surface of the weaving unit, and increasing the difficulty of the conductive material 1012 to compensate for the height difference. Therefore, it can be further considered to thin the first fiber filament 111 constituting the first wire bundle 10 to one or two layers, and thin the second fiber filament 211 constituting the second wire bundle 20 to one or two layers, because the number of layers of the first fiber filament 111 and the second fiber filament 211 is reduced, the overall surface of the cloth base material 1011 of the conductive cloth 101 itself is more close to a plane relative to the cloth base material 1011 of three or more layers of fiber filaments, so as to reduce the area and the thickness value of the height difference that needs to be compensated by the conductive material 1012. At the same time, the thickness of the conductive cloth 101 can be reduced, and the mass of the thinned conductive cloth 101 is also reduced accordingly, thereby reducing the amount of adhesive 102 used for bonding the conductive cloth 101, and when the conductive cloth 101 is applied to the conductive foam 100, the volume and the weight of the conductive foam 100 can be reduced, so as to realize the lightness, thinness and miniaturization of the conductive foam 100.

[0207] The conductive cloth 101 in the related art is deeply recessed at the weaving nodes (i.e., at D1 in FIG. 2), so that the conductive cloth 101 presents a concave-convex shape, further increasing the area and the height difference value, and increasing the difficulty of the conductive material 1012 to compensate for the height difference. Therefore, it can be considered to further improve the flatness of the cloth base material 1011 by reducing the weaving nodes, so that the overall surface of the cloth base material 1011 of the conductive cloth 101 itself is more close to a plane relative to more cloth base material 1011 of the weaving nodes, so as to reduce the area and the thickness value of the height difference that needs to be compensated by the conductive material 1012. In the embodiment, the number of the first fiber filament 111 in the first wire 11 and the number of the second fiber filament 211 in the second wire 21 are further limited, compared with the related art, under the condition that the conductive cloth 101 has the same area, the number of the weaving nodes can be reduced by 40%, so that the surface of the conductive cloth 101 is approximately a plane, and the effective contact area can be close to 100% when contacting the device to be connected.

[0208] In the above embodiments, the fiber filament can also be pre-processed to have a cross-sectional width greater than a cross-sectional height, i.e., the fiber filament is flat, and the cross-section is approximately elliptical. Such a fiber filament woven into a conductive cloth 101 has two effects: one is that a larger size conductive cloth 101 can be woven with fewer fiber filaments; and two is that the cross-sectional width of the fiber filament is wider, so that the fiber filament fills the pores formed due to the reduction in the number of layers of the fiber filament, so that the surface of the conductive cloth 101 is more close to a plane.

[0209] In an embodiment provided by the present application, the fiber filaments in the base substrate 1011 can be metal fiber filaments or non-metal fiber filaments, which are not limited herein. Alternatively, in the above-mentioned embodiments, the metal fiber filament material includes at least one of copper, aluminum, silver, gold, magnesium, zinc, iron, lead, nickel, cobalt, tin, bismuth, palladium, platinum, ruthenium, and rhodium. Alternatively, in the above-mentioned embodiments, the non-metal fiber filament material includes at least one of natural fiber, carbon fiber, ceramic fiber, silicon carbide fiber, glass fiber, polyamide fiber (nylon), polyester fiber (polyester), polysulfone terephthalamide fiber (PSA), aramid fiber, and poly-p-phenylene-benzobisoxazole fiber (PBO). Specifically, the natural fiber can be at least one of cotton fiber, hemp fiber, wool fiber, and silk fiber.

[0210] Alternatively, the non-metal fiber filaments can be plated with a metal plating layer through physical vapor deposition (PVD) and chemical vapor deposition (CVD).

[0211] In an embodiment provided by the present application, the material of the first fiber filaments 111 and the second fiber filaments 211 can be the same, for example, both can be copper metal fiber filaments, both can be silver metal fiber filaments, both can be copper-plated glass fiber, or both can be copper-plated aramid fiber.

[0212] In an embodiment provided by the present application, the material of the first fiber filaments 111 and the second fiber filaments 211 can be different, for example, the first fiber filaments 111 are copper metal fiber filaments, and the second fiber filaments 211 are silver metal fiber filaments; the first fiber filaments 111 are silver metal fiber filaments, and the second fiber filaments 211 are copper-plated glass fiber; the first fiber filaments 111 are copper-plated aramid fiber, and the second fiber filaments 211 are copper-plated glass fiber.

[0213] Finally, it should be noted that the above description is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electrically conductive cloth for use in connection with a device, characterized in that, The conductive cloth comprises: a cloth substrate, the cloth substrate is interlaced by a plurality of first strands and a plurality of second strands, the cloth substrate comprises a plurality of interlaced units, each of the interlaced units is composed of an adjacent first strand segment and a second strand segment, the first strand segment is a segment of the first strand, the first strand segment is interlaced on the second strand, the second strand segment is a segment of the second strand, the second strand segment is interlaced on the first strand; wherein the first strand segment and the second strand segment have a height difference in a direction towards a first surface of the device; a conductive material, the conductive material is coated on a surface of the cloth substrate towards the device; wherein the conductive material is configured to have a thickness difference between the conductive material coated on a first surface of the interlaced unit and the conductive material coated on a second surface of the interlaced unit; when the difference between the thickness difference and the height difference in the area corresponding to the interlaced unit on the cloth substrate under the condition that the conductive cloth is applied with an extrusion pressure of 0.2N-0.4N is less than or equal to 5μm, the interlaced unit is an effective interlaced unit; wherein the ratio of the number of effective interlaced units to the number of interlaced units on the cloth substrate is greater than or equal to 50%.

2. The conductive cloth according to claim 1, wherein The effective interlaced unit comprises an effective first surface and an effective second surface, and the effective interlaced unit is configured to have a surface of the conductive material coated on the effective first surface and a surface of the conductive material coated on the effective second surface tend to be horizontal under the condition that the conductive cloth is applied with an extrusion pressure of 0.2N-0.4N.

3. The conductive cloth according to claim 1 or 2, wherein The difference between the thickness difference and the height difference is less than or equal to a first threshold value, which includes: The effective first surface comprises a highest point of the effective interlaced unit, and the effective second surface comprises a lowest point of the effective interlaced unit; Or, the effective first surface comprises a lowest point of the effective interlaced unit, and the effective second surface comprises a highest point of the effective interlaced unit; The height difference between the highest point and the lowest point is a first value; The thickness difference between the conductive material coated on the highest point and the conductive material coated on the lowest point is a second value, and the difference between the first value and the second value is less than or equal to 5μm.

4. The conductive cloth according to any one of claims 1 to 3, wherein, The difference between the thickness difference and the height difference is less than or equal to 3μm.

5. The conductive cloth according to any one of claims 1 to 4, wherein The conductive cloth is configured to have a contact area fraction with the device greater than or equal to 50% under the condition that the conductive cloth is applied with an extrusion pressure of 0.2N-0.4N.

6. The conductive cloth according to any one of claims 1 to 5, wherein, Each of the first strands is a layer of first wire, and the first wire comprises a plurality of first fiber filaments. Each of the second strands is a layer of second wire, and the second wire comprises a plurality of second fiber filaments.

7. The conductive cloth according to any one of claims 1 to 6, wherein The conductive material comprises a metal plating layer, and the thickness of the metal plating layer is greater than or equal to 10μm.

8. The conductive cloth according to claim 7, wherein The metal plating layer comprises a copper layer, a nickel layer, and a gold layer, and the thickness of the gold layer is greater than or equal to 0.5μm.

9. The conductive cloth according to claim 7, wherein The metal plating layer comprises a copper layer, a nickel layer, and a silver layer, and the thickness of the silver layer is greater than or equal to 0.5μm.

10. The conductive cloth according to any one of claims 1 to 6, wherein, The conductive material is a conductive paste, and the thickness of the conductive paste is greater than or equal to 10 μm.

11. The conductive cloth according to claim 10, wherein The surface of the conductive cloth is coated with the conductive paste.

12. The conductive cloth according to claim 11, wherein, The conductive material further comprises a metal plating layer, and the cloth substrate, the metal plating layer, and the conductive paste are sequentially stacked in the thickness direction of the conductive cloth.

13. The conductive cloth of claim 10, wherein, The cloth substrate is impregnated with the conductive paste.

14. The conductive cloth according to claim 13, wherein, The conductive material further comprises a metal plating layer, and the surface of the conductive cloth facing the device comprises the metal plating layer and the conductive paste.

15. The conductive cloth according to any one of claims 1 to 14, wherein, The material of the conductive paste comprises at least one of conductive silver paste, conductive copper paste, conductive nickel paste, and conductive graphene paste.

16. The conductive cloth according to any one of claims 1 to 15, wherein, The cloth substrate does not have the second wire harness in some areas.

17. An electrically conductive foam, characterized in that, The conductive cloth comprises any one of claims 1-16.

18. The electrically conductive foam of claim 17, wherein, The conductive cloth is further bonded to the surface of the foam core by the adhesive.

19. The electrically conductive foam of claim 18, wherein, The conductive cloth is further bonded to the surface of the foam core by the adhesive.

20. The electrically conductive foam of claim 19, wherein, The surface of the foam core has an insulation adhesive for bonding the foam core to the device.

21. The electrically conductive foam according to any one of claims 18-20, wherein, The insulation adhesive is located in the middle or adjacent to the edge on the surface of the foam core having the insulation adhesive.

22. The electrically conductive foam according to any one of claims 18-20, wherein, The surface of the foam core has a relief area without the conductive cloth.

23. The electrically conductive foam according to any one of claims 18-20, wherein, The number of the conductive cloth is two, and the two conductive cloths are oppositely arranged on the surface of the foam core.

24. An electronic device, comprising: The adhesive is a conductive paste, and the conductive paste is impregnated from the pores of the cloth substrate to form the conductive material or part of the conductive material.

25. The electronic device of claim 24, wherein, The conductive foam comprises any one of claims 17-23. The device is a screen or a metal middle frame. The device is a screen or a metal middle frame.

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