Electrically conductive grid and preparation method therefor, and transparent flexible printed circuit and electronic device

Abstract

The present invention relates to the technical field of electronic devices. Disclosed are an electrically conductive grid and a preparation method therefor, and a transparent flexible printed circuit and an electronic device. The preparation method for an electrically conductive grid comprises: covering a surface of a conductor with a dry film; exposing the dry film, and removing a portion of the dry film by means of a developer, so as to leave a preset dry-film grid corresponding to an electrically conductive grid to be formed; performing a first etching process, in which a vertical etching rate is lower than a lateral etching rate, on an exposed region of the conductor, so as to form the electrically conductive grid; and performing stripping on the preset dry-film grid, and then performing micro-etching treatment on the electrically conductive grid by means of a second etching process. The cross-section of each line of the electrically conductive grid obtained by means of the first etching process is in a quasi-trapezoidal shape, and the cross-section of each line of the electrically conductive grid obtained by means of the second etching process is in a quasi-rectangular shape. By means of the technical solution provided by the present invention, an electrically conductive grid that is relatively thick and relatively narrow can be prepared.

Description

Conductive mesh and its fabrication method, transparent flexible circuit board and electronic device

[0001] This application claims priority to Chinese Patent Application No. 202411907009.0, filed on December 23, 2024, entitled “Conductive Mesh and Method for Preparing the Same, Transparent Flexible Circuit Board and Electronic Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of electronic device technology, and in particular to a conductive mesh and its preparation method, a transparent flexible circuit board, and an electronic device. Background Technology

[0003] Existing subtractive methods for preparing conductive meshes are prone to tailing, which severely limits the linewidth and thickness of the formed conductive mesh, affecting its conductivity and application range. Summary of the Invention

[0004] The main objective of this invention is to provide a conductive mesh and its preparation method, a transparent flexible circuit board, and an electronic device, which can prepare both thick and fine conductive meshes.

[0005] To achieve the above objectives, the method for preparing the conductive mesh proposed in this invention includes:

[0006] Cover the surface of the conductor with a dry film;

[0007] The dry film is exposed and a portion of it is removed by a developer, leaving a pre-set dry film grid that corresponds to the pre-formed conductive grid.

[0008] A first etching process is performed on the exposed area of ​​the conductor, with the vertical etching rate being lower than the lateral etching rate, to form a conductive mesh; wherein the cross-section of the conductive mesh formed in this step is trapezoidal in shape, the trapezoidal shape having a first bottom near the dry film and a second bottom away from the dry film, the width of the first bottom being greater than the width of the second bottom.

[0009] After stripping the preset dry film mesh, the conductive mesh is micro-etched through a second etching process; wherein, the width difference between the first bottom and the second bottom of the conductive mesh after this step is smaller, and the cross-section of the resulting conductive mesh line is rectangular in shape.

[0010] In one embodiment, the etching agent used in the first etching process includes copper ions and hydrochloric acid.

[0011] In one embodiment, the etching agent used in the second etching process includes copper ions, hydrogen peroxide, and sulfuric acid.

[0012] In one embodiment, the width of the preset dry film mesh is 50% to 80% larger than the width of the line body of the preformed conductive mesh.

[0013] In one embodiment, the width of the preset dry film mesh is 60% to 70% larger than the width of the line body of the preformed conductive mesh.

[0014] In one embodiment, the step of coating the surface of the conductor with a dry film is further included before the step of:

[0015] The surface of the conductor is micro-etched through a third etching process.

[0016] In one embodiment, the etching agent used in the third etching process includes copper ions, hydrogen peroxide, and sulfuric acid.

[0017] The present invention also proposes a conductive mesh, which is prepared by the aforementioned method for preparing conductive mesh.

[0018] In one embodiment, the ratio of the line thickness to the line width of the conductive mesh is greater than or equal to 1.

[0019] In one embodiment, the linewidth of the conductive mesh is less than 10 micrometers.

[0020] In one embodiment, the thickness of the conductive mesh wires is 6 micrometers to 12 micrometers.

[0021] In one embodiment, the ratio of the line thickness to the line width of the conductive mesh is greater than or equal to 1.4.

[0022] The present invention also proposes a transparent flexible circuit board, including the aforementioned conductive mesh.

[0023] The present invention also proposes an electronic device comprising the aforementioned conductive mesh.

[0024] In one embodiment, the electronic device is configured as a head-mounted display device, the lenses of which are provided with at least one of an antenna structure, an electrochromic film, and an electrothermal film, wherein at least one of the antenna structure, the electrochromic film, and the electrothermal film includes the conductive mesh.

[0025] In one embodiment, the electronic device includes a touch screen, the touch screen including the conductive mesh.

[0026] In one embodiment, the electronic device has an electromagnetic shielding structure, the electromagnetic shielding structure including the conductive mesh.

[0027] In the technical solution of this invention, the conductor is over-etched through a first etching process, so that the cross-section of the conductive mesh has an inverted trapezoidal or trapezoidal shape. This avoids tailing when etching thicker conductors, preventing excessive linewidth on the lower surface and ensuring that the linewidth on the lower surface meets the requirements for ultra-fine lines in some fields. Then, the conductive mesh formed by the first etching process is micro-etched through a second etching process. The second etching process mainly etches one side of the upper surface of the line, so that the linewidth on the upper surface of the line can also meet the requirements for ultra-fine lines. It can also correct the inverted trapezoidal cross-section of the line obtained by the first etching process, resulting in a rectangular cross-section shape. This ensures high width consistency of the line in the line thickness direction, which is beneficial to ensuring the conductivity of the conductive mesh. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 is a schematic flowchart of an embodiment of the conductive mesh preparation method provided by the present invention;

[0030] Figure 2 is a schematic diagram of a portion of the process forming structure of an embodiment of the conductive mesh preparation method provided by the present invention;

[0031] Figure 3 is a schematic diagram of the fabrication process of an embodiment of the transparent flexible circuit board provided by the present invention;

[0032] Figure 4 is a structural schematic diagram of an embodiment of the transparent flexible circuit board provided by the present invention;

[0033] Figure 5 is a schematic diagram of a structural embodiment of the conductive mesh provided by the present invention;

[0034] Figure 6 is a schematic diagram of another embodiment of the conductive mesh provided by the present invention;

[0035] Figure 7 is a schematic diagram of another embodiment of the conductive mesh provided by the present invention;

[0036] Figure 8 is a structural schematic diagram of another embodiment of the conductive mesh provided by the present invention;

[0037] Figure 9 is a schematic diagram of the structure of a conductive mesh installed on the lens of a head-mounted display device.

[0038] Explanation of reference numerals: 100, conductive grid; 110, main body area; 120, buffer zone; 130, pin area; 101, first line body; 102, second line body; 103, third line body; 104, second boundary line body; 210, substrate; 220, cover layer; 230, adhesive layer.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0042] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0043] This invention proposes a method for preparing a conductive mesh.

[0044] Please refer to Figures 1 and 2. In one embodiment of the present invention, the method for preparing the conductive mesh includes:

[0045] S200, Cover the surface of the conductor with a dry film;

[0046] S300, Expose the dry film and remove part of the dry film with a developer, leaving a preset dry film grid corresponding to the pre-formed conductive grid;

[0047] S400, A first etching process is performed on the exposed area of ​​the conductor, with the vertical etching rate being lower than the lateral etching rate, to form a conductive mesh;

[0048] S500: After stripping the preset dry film mesh, the conductive mesh is micro-etched through the second etching process.

[0049] In step S400, the cross-section of the conductive mesh formed has a trapezoidal shape, which has a first bottom near the dry film and a second bottom away from the dry film, and the width of the first bottom is greater than the width of the second bottom.

[0050] After step S500, the width difference between the first bottom and the second bottom of the conductive mesh is smaller, and the cross-section of the resulting conductive mesh line body is rectangular.

[0051] It is understandable that the side of the conductor covering the dry film is generally located at the top, and the side of the conductor away from the dry film is generally provided with a substrate. The conductor and the substrate are generally fixed together by adhesive.

[0052] In step S400, the first bottom of the conductive mesh formed in the wire cross-section is trapezoidal in shape, and this trapezoidal shape is also inverted trapezoidal. Specifically, in step S400, the vertical etching rate of the first etching process is less than the lateral etching rate, which can create an over-etching effect. In addition, the dry film can protect the upper surface of the conductor, so that the etching amount on the lower surface of the conductor is greater than the etching amount on the upper surface. This makes the overall wire cross-section of the conductive mesh have a shape that is wider at the top and narrower at the bottom, and the wire thickness gradually decreases from top to bottom.

[0053] In step S500, since the dry film is removed, the upper surface of the conductive mesh line no longer has a protective structure, while the lower surface is still protected by the substrate. This results in a higher etching rate on the upper surface than on the lower surface. The second etching process at this point can etch more of the upper surface of the line, thereby reducing the width difference between the first and second bottom edges and mitigating the slope from the first to the second bottom edge. This allows the two sides of the trapezoidal shape to be nearly perpendicular to the first and second bottom edges, resulting in a rectangular cross-section of the conductive mesh line obtained in this step. Because the second etching process is a micro-etching process with a small etching amount, it does not excessively damage the shape of the line. Its main function is to correct the inverted trapezoidal cross-section obtained in step S400 towards a rectangular cross-section.

[0054] In the technical solution of this invention, the conductor is over-etched through a first etching process, so that the cross-section of the conductive mesh has an inverted trapezoidal or trapezoidal shape. This avoids tailing when etching thicker conductors (e.g., conductors with a thickness of 6 to 12 micrometers), preventing excessive linewidth on the lower surface and ensuring that the linewidth on the lower surface meets the requirements for ultra-fine lines in some fields (e.g., linewidth within 10 micrometers). Then, the conductive mesh formed by the first etching process is micro-etched through a second etching process. The second etching process mainly etches one side of the upper surface of the line, so that the linewidth on the upper surface of the line also meets the requirements for ultra-fine lines. It can also correct the inverted trapezoidal cross-section of the line obtained by the first etching process, resulting in a rectangular cross-section shape. This ensures high width consistency of the line in the thickness direction, which is beneficial to ensuring the conductivity of the conductive mesh.

[0055] In the prior art, in order to achieve a transparent visual effect in the mesh area of ​​the conductive mesh, the line width of the mesh line is set to be relatively small. Due to the limitations of the manufacturing process, the line thickness of the mesh line is generally smaller than the line width, which results in poor mesh line strength of the conductive mesh and easy breakage during the manufacturing process.

[0056] This invention enables the stable and reliable molding of thicker conductors into ultra-fine conductive meshes, and allows the fabrication of conductive meshes with a line thickness-to-width ratio greater than 1. This improves the structural stability of the conductive mesh, making it less prone to breakage during the manufacturing process and enhancing its manufacturability. Simultaneously, the thicker lines provide better conductivity, higher current carrying capacity, and superior heat dissipation, ensuring the performance of the conductive mesh. The line width can be maintained at a relatively fine level to ensure a transparent visual effect, thus guaranteeing applicability in fields such as touchscreens and transparent antennas.

[0057] In one embodiment, the etchant used in the first etching step includes copper ions and hydrochloric acid. Thus, the conductor can be etched using hydrochloric acid, while the copper ions act as a buffer during the etching process, helping to maintain a stable pH value or other key parameters, ensuring the consistency and repeatability of the etching conditions. Without loss of generality, the conductor is made of copper, which helps prevent the generation of by-reaction products during the etching process. Of course, in other embodiments, the etchant may also include nitric acid, phosphoric acid, etc.

[0058] In one embodiment, the etchant used in the second etching step includes copper ions, hydrogen peroxide, and sulfuric acid. That is, the conductor is etched using hydrogen peroxide and sulfuric acid, and copper ions act as a buffer during the etching process. Of course, in other embodiments, sodium persulfate (SPS) + sulfuric acid series micro-etching solutions or potassium persulfate surface micro-etching agents can also be used.

[0059] In one embodiment, the width of the preset dry film mesh is 50% to 80% larger than the width of the pre-formed conductive mesh. Thus, in the first etching step, the mesh lines of the preset dry film mesh provide reliable protection for the upper surface of the pre-formed conductive mesh. Under the limitation of the preset dry film mesh's mesh line width, the lower surface of the conductor is not over-etched, and the width of the etched line is comparable to the pre-formed width. The excess width of the upper surface of the line compared to the pre-formed line width is also maintained within a suitable range. After the second etching step, this excess width is reduced to a width comparable to the pre-formed line width. Preferably, the width of the preset dry film mesh is 60% to 70% larger than the width of the pre-formed conductive mesh. Of course, under other process conditions, this ratio can also be between 50% and 60%, or between 70% and 80%, or less than 50% or greater than 80%.

[0060] In one embodiment, referring to Figures 1 and 2 together, the step S200 includes the following step:

[0061] S100. The surface of the conductor is micro-etched through the third etching process.

[0062] Specifically, the etching agents used in the third etching process include copper ions, hydrogen peroxide, and sulfuric acid. That is, the surface of the conductor is micro-etched using hydrogen peroxide and sulfuric acid, with copper ions acting as a buffer. Step S100 removes the oxide layer on the conductor surface, enhancing the adhesion of the conductor surface to the dry film. At the same time, it can thin the incoming conductor, making the conductor thickness comparable to the pre-formed wire thickness.

[0063] Without loss of generality, the preset dry film grid in step S300 includes a first grid area, a second grid area, and a solid area distributed sequentially. A first boundary line body is provided between the first grid area and the second grid area. The first grid area has a first grid line connecting the first boundary line body. The second grid area is provided with at least one row of second grid lines distributed along the extension direction of the first boundary line body. The position where the boundary line body connects to the first grid line is staggered from the position where the first boundary line body connects to the second grid line.

[0064] The conductive mesh thus formed can have a shape that is roughly the same as the preset dry film mesh. Please refer to Figures 5 to 8. The conductive mesh will form a pin area 130 corresponding to the solid area, a buffer area 120 corresponding to the first mesh area, and a main body area 100 corresponding to the second mesh area. A second dividing line body 104 corresponding to the first dividing line body is provided between the buffer area 120 and the main body area 110. The main body area 110 is formed with a first line body 101 connecting to the second dividing line body 104 corresponding to the first mesh line. The buffer area 120 is formed with at least one row of second lines body 102 distributed along the extension direction of the second dividing line body 104 corresponding to the second mesh line. The position of the second dividing line body 104 connecting to the first line body 101 is staggered from the position of the second dividing line body 104 connecting to the second line body 102.

[0065] This conductive mesh, through the buffer zone 120, releases stress between the main body region 110 and the pin region 130. The connection position of the second line 102 of the buffer zone 120 on the second boundary line 104 is staggered from the connection position of the first line 101 of the main body region 110 on the second boundary line 104. This disperses stress between the pin region 130 and the main body region 110, allowing for a more even load distribution and reducing the risk of localized overload. It also lowers the probability of line detachment or breakage at the connection point between the pin region 130 and the main body region 110 during manufacturing, thus improving the manufacturability of the conductive mesh 100. Furthermore, the extremely fine linewidth of the lines in the main body region 110 ensures the structural stability of the conductive mesh 100. Simultaneously, the conductive mesh 100 exhibits good electrical performance and high light transmittance, making it suitable for applications such as transparent antennas and touch screens. Furthermore, since the buffer zone 120 also forms a grid, it has little impact on the transmittance and conductivity of the conductive grid 100, which helps to ensure the performance of the conductive grid 100 and its applicability to fields such as transparent antennas and touch screens.

[0066] Optionally, in the preset dry film grid, the second grid lines are arranged in multiple rows. The second grid area also includes a third grid line disposed between two adjacent rows of the second grid lines. The third grid line runs parallel to the dividing line, and the position where the third grid line connects to one of the adjacent rows of the second grid lines is staggered from the position where it connects to another adjacent row of the second grid lines. Thus, correspondingly, in the conductive grid, referring to Figure 5, the buffer zone 120 will form multiple rows of the second line bodies 102. A third line body corresponding to the third grid line will be formed between two adjacent rows of the second line bodies. The third line body runs parallel to the first dividing line body, and the position where the third line body connects to one of the adjacent rows of the second line bodies is staggered from the position where it connects to another adjacent row of the second line bodies. In the conductive mesh thus formed, the buffer zone 120 achieves further stress dispersion through the staggered arrangement of multiple rows of wires. The load can be evenly distributed in the extension directions of the second wire 102 and the third wire 103, which can further reduce the risk of excessive local stress and help prevent the wires of the buffer zone 120 from floating away or breaking, thereby ensuring the structural stability of the conductive wires.

[0067] Furthermore, in the preset dry film grid, the number of rows of the second dividing line 104 is set to at least four. In this way, in the conductive grid, the buffer can form at least four rows of second lines 102, which can effectively disperse the stress between the pin area 130 and the main body area 110, reduce the stress on the lines of the buffer 120, and thus prevent the lines of the buffer 120 from floating or breaking.

[0068] Optionally, in the preset dry film mesh, the line width of the second mesh line is at least twice the line width of the first mesh line. Correspondingly, in the conductive mesh, the line width of the second wire 102 is at least twice the line width of the first wire 101. Thus, by increasing the line width of the second wire 102, its resistance to external forces can be improved, making it less prone to deformation and thus helping to prevent breakage, thereby ensuring the structural stability of the conductive mesh 100. Without loss of generality, a row of second mesh lines is provided; see Figure 6, where a corresponding row of second wires 102 is also formed. Of course, in other embodiments, the line width of the second mesh line can also be 1.5 times or 1.8 times the line width of the first mesh line. A line width greater than the first mesh line can, to a certain extent, improve the deformation resistance of the second wire 102.

[0069] In the preset dry film mesh, the distance between the solid area and the boundary line is greater than or equal to 8 mm. Correspondingly, in the conductive mesh, the distance between the pin area 130 and the boundary line 104 is greater than or equal to 8 mm. This ensures that the buffer zone 120 can cover the high-risk area between the pin area 130 and the main body area 110, which is the area where the wire is prone to breakage. The mesh of the buffer zone 120 can thus disperse stress in this high-risk area, preventing structural damage at the connection between the pin area 130 and the main body area 110, thereby ensuring the structural stability of the conductive mesh 100. Of course, in other embodiments, this distance can also be adjusted to less than 8 mm, provided that the structural stability of the conductive mesh 100 is ensured.

[0070] Without loss of generality, the exposure of the dry film in step S300 is as follows:

[0071] The dry film is exposed by a mask; wherein the shape of the mask corresponds to the preset dry film grid.

[0072] That is, the shapes of the mask, the pre-formed dry film grid, and the conductive grid will be largely the same. The shape of the mask determines the shape of the conductive grid. The shape of the mask can be customized according to the shape of the pre-formed conductive grid, and the exposure process quality can be controlled to ensure that the pre-formed dry film grid and the pre-formed conductive grid correspond to each other. In this way, the conductive grid can be reliably formed. Of course, in other embodiments, the dry film can also be exposed by electron beam direct writing or laser direct writing.

[0073] The process for manufacturing transparent flexible circuit boards also includes the steps of the aforementioned conductive mesh preparation method. The process flow for manufacturing transparent flexible circuit boards is shown in Figure 3. The raw materials for manufacturing transparent flexible circuit boards are generally an adhesive substrate and a conductor layer. By processing the conductor layer using the steps described above, a conductive mesh can be formed. After processes such as punching, slitting, and blackening, a CVL (Coverlay) is attached to the formed conductive mesh and laminated to obtain the transparent flexible circuit board. Subsequent processes such as acid washing, electrical testing, and slitting can be performed as needed.

[0074] This invention also proposes a conductive mesh, which is prepared by the aforementioned conductive mesh preparation method. The conductive mesh thus prepared has thicker and finer lines. The thicker lines improve the structural stability of the conductive mesh, making it less prone to line breakage during the manufacturing process, thus improving the manufacturability of the conductive mesh. In use, the thicker lines provide better conductivity, the ability to carry large currents, and excellent heat dissipation performance, which helps ensure the performance of the conductive mesh. The line width can be maintained at a relatively fine level to ensure a transparent visual effect, thereby ensuring applicability in fields such as touch screens and transparent antennas.

[0075] Without loss of generality, referring to Figures 2, 5 to 8, the conductive mesh 100 includes multiple preset lines connected to form a mesh. The ratio of the thickness to the width of each preset line is greater than or equal to 1. The conductive mesh 100 includes a pin area 130 and a main body area 110, with the main body area 110 having multiple preset lines. This ensures the strength, conductivity, and visual transparency of the lines in the main body area. Preferably, the ratio of the thickness to the width of the preset lines is greater than or equal to 1.4, allowing for a smaller line width and facilitating a more transparent visual effect. Furthermore, a ratio of less than 3 makes the lines less prone to tipping over, thus ensuring the structural stability of the conductive mesh 100.

[0076] In one embodiment, the line width of the preset line is within 10 micrometers. This allows the preset line to be relatively thin, making it suitable for more precise applications and easier to create a transparent visual effect.

[0077] In one embodiment, the thickness of the preset line body is 6 to 12 micrometers. That is, the thickness of the preset line body is greater than or equal to 6 micrometers and less than or equal to 12 micrometers. In this way, the thickness and width of the preset line body are both within a suitable range to ensure the performance of the conductive grid 100. Preferably, the thickness of the preset line body is 8 to 10 micrometers.

[0078] In one embodiment, referring to Figures 2 and 4 together, the conductive mesh 100 is disposed on the substrate 210. The preset line has a second bottom and a first bottom that are relatively distributed in the line thickness direction. The second bottom is located on the side closer to the substrate 210. The line width of the first bottom w2 exceeds the line width w1 of the second bottom by less than 10%. That is, the line width w2 at the first bottom exceeds the line width w1 at the second bottom, and the ratio of the line width exceeding the second bottom by the first bottom to the line width of the second bottom is less than 10%, i.e., the value of (w2-w1) / w1 is less than or equal to 10%. In this way, the preset line can exhibit a relatively uniform line width in the line thickness direction, which is beneficial to ensuring the conductivity and structural stability of the preset line.

[0079] It is understood that the second bottom layer is connected to the substrate 210 via adhesive layer 230, while the first bottom layer is connected to the cover layer 220 or other structures via adhesive layer 230. Due to the larger linewidth at the first bottom layer, the contact area between the first bottom layer and the cover layer 220 or other upper components can be increased, thereby improving the uniformity of lateral current distribution and reducing surface resistance. When viewed from one side, the first bottom layer can shield other parts of the conductive mesh 100, making the mesh appear finer and less conspicuous, thus improving the product's visual appearance. Furthermore, when the cover layer 220 or other materials are bonded to the conductive mesh 100, the wider first bottom layer helps guide and disperse the adhesive, ensuring its uniform distribution and avoiding the formation of bubbles or voids, thereby improving the overall packaging quality. Of course, in other embodiments, the second bottom layer may also have a wider linewidth.

[0080] In one embodiment, referring to Figure 6, the line width of the preset line gradually increases from the second bottom to the first bottom. This allows the line width to vary uniformly, which helps ensure the structural stability and conductivity of the preset line. Of course, in other embodiments, the line width of the preset line may also have a uniform portion in the line thickness direction.

[0081] In one embodiment, referring to Figure 6, the cross-section of the preset line body is configured as a quasi-isosceles trapezoid or a quasi-rectangular shape. It can be understood that this cross-section is formed by cutting along the line width direction. The quasi-isosceles trapezoid or quasi-rectangular shape indicates that the preset line body has strong symmetry in the line width direction, which is beneficial for ensuring the structural stability and conductivity of the preset line body. Specifically, configuring the cross-section of the preset line body as a quasi-isosceles trapezoid or a quasi-rectangular shape means that the shapes of the two surfaces of the preset line body distributed in the line width direction closely match the two sides of an isosceles trapezoid or the two long sides of a rectangle, with low deviation. Without loss of generality, the maximum deviation should preferably not exceed 5% of the average line width. Of course, in other embodiments, the cross-section of the preset line body can also be configured as a shape close to a non-rectangular parallelogram.

[0082] In one embodiment, referring to Figures 5 to 8, the conductive mesh 100 further includes a buffer zone 120 located between the pin area 130 and the main body area 110. A second dividing line 104 is provided between the buffer zone 120 and the main body area 110. The main body area 110 is provided with a first line 101 connecting the second dividing line 104. The buffer zone 120 is provided with at least one row of second lines 102 distributed along the extension direction of the second dividing line 104. The positions where the second dividing line 104 is connected to the first line 101 are staggered from the positions where the second dividing line 104 is connected to the second line 102.

[0083] The first line body 101 can be configured as a row distributed along the extension direction of the second dividing line body 104 to construct a rectangular grid. The first line bodies 101 can also be intersecting to construct a rhomboid grid. In constructing a rectangular grid, a row of first line bodies 101 can include at least two first line bodies 101 to construct at least one grid in the area of ​​the row. The remaining areas of the main body area 110 are also constructed in this way to form multiple rows of grids. Alternatively, the two ends of the first line body 101 can be connected to the two second dividing line bodies 104 respectively to form a row of grids in the main body area 110. By setting multiple first line bodies 101, multiple grids can be formed in the area of ​​the row.

[0084] The second line body 102 can be arranged in a row, with the second dividing line body 104 connected to one end of the second line body 102, and the pins of the pin area 130 connected to the other end of the second line body 102. When there is a vacancy in the pin area 130, the buffer 120 also has an edge line body parallel to the second dividing line body 104 on the side near the pin area 130, for connecting the end of the second line body 102 near the pin area 130.

[0085] The second line body 102 can also be configured in two or more rows. A third line body 103 parallel to the second dividing line body 104 is provided between two adjacent rows of second line bodies 102 for connecting the two connected rows of second line bodies 102. The second line body 102 near the main body area 110 is connected to the second dividing line body 104, and the second line body 102 near the pin area 130 is connected to the pin or edge line body of the aforementioned pin area 130.

[0086] In this invention, the buffer zone 120 effectively releases the stress between the main body region 110 and the pin region 130. The connection positions of the second wire 102 of the buffer zone 120 on the second boundary line 104 are staggered with the multiple connection positions of the first wire 101 of the main body region 110 on the second boundary line 104. This disperses the stress between the pin region 130 and the main body region 110, allowing for a more uniform load distribution and reducing the risk of localized overload. It also lowers the probability of wire detachment or breakage at the connection points between the pin region 130 and the main body region 110, thereby improving the manufacturability of the conductive mesh 100. Furthermore, the extremely fine linewidth of the wires in the main body region 110 ensures the structural stability of the conductive mesh 100. Simultaneously, the conductive mesh 100 exhibits good electrical performance and high light transmittance, making it suitable for applications such as transparent antennas and touch screens. Moreover, since the buffer zone 120 also forms a mesh, its impact on the light transmittance and conductivity of the conductive mesh 100 is minimal, further ensuring the performance of the conductive mesh 100.

[0087] Among them, the lines forming the grid include the lines of the buffer zone 120, the second boundary line 104, and the lines of the main body 110, which can be set as preset lines as needed, or set with reference to some features in the aspect ratio, thickness value and cross-sectional shape of the preset lines.

[0088] Furthermore, the connection positions of the second line 102 of the buffer zone 120 on the second dividing line 104 and the connection positions of the first line 101 of the main body region 110 on the second dividing line 104 are staggered, which can further improve the degree of stress dispersion and help avoid the line floating or breaking at the connection between the pin region 130 and the main body region 110.

[0089] In one embodiment, referring to Figures 5, 6, and 8, multiple second lines 102 are arranged alternately in the same row. This allows a quadrilateral grid to be formed by the row of second lines 102, with the connection points on the boundary lines between adjacent second lines 102 not overlapping, which is more conducive to improving the stress dispersion effect. Of course, in other embodiments, provided that the stress dispersion requirements are met, multiple second lines 102 in the same row can also be connected sequentially to form a triangular grid.

[0090] Furthermore, in this embodiment, multiple second lines 102 in the same row are parallel. This allows for the construction of a parallelogram-shaped mesh, which improves the stress distribution uniformity of the buffer zone 120, thereby ensuring the structural stability of the conductive mesh 100. Of course, in other embodiments, multiple second lines 102 in the same row can also be constructed to form a trapezoidal mesh, wherein an isosceles trapezoidal mesh is beneficial for ensuring the stress distribution uniformity of the buffer zone 120.

[0091] Furthermore, in this embodiment, multiple second wires 102 in the same row are evenly spaced. This results in a relatively uniform mesh size formed by a row of second wires 102, which helps to further improve the stress distribution uniformity of the buffer zone 120, thereby ensuring the structural stability of the conductive mesh 100. Of course, in other embodiments, the distribution density of the second wires 102 can be increased in areas with higher stress concentration and decreased in areas with lower stress.

[0092] Optionally, referring to Figures 5 and 6, the second line 102 is parallel to the distribution direction of the pin area 130 and the main body area 110. Parallel means parallel or approximately parallel, so that the second line 102 can be set perpendicular or approximately perpendicular to the second dividing line 104, thereby constructing a rectangular grid, which facilitates the processing and shaping of the conductive grid 100. Optionally, referring to Figure 8, the second line 102 is set at an angle relative to the distribution direction of the pin area 130 and the main body area 110. The parallelogram grid formed in this way has strong deformation capability and can absorb a certain amount of energy through deformation after being subjected to external force, thereby reducing the possibility of breakage.

[0093] In one embodiment, referring to FIG7, the multiple second lines 102 in the same row include multiple groups of lines formed by the intersection of two first lines 101. In this way, the groups of lines can connect with the structures on both sides to form a triangular structure. The triangular structure improves the structural stability of the buffer zone 120, thereby ensuring the connection stability between the main body area 110 and the pin area 130.

[0094] Furthermore, in this embodiment, the adjacent sides of two adjacent line groups are connected to the second dividing line 104 at the same position. This creates a direct connection between adjacent line groups, providing more paths for stress conduction and dispersion, thereby further improving the structural stability of the buffer zone 120 and ensuring the connection stability between the main body area 110 and the pin area 130. Of course, in other embodiments, the adjacent sides of two adjacent line groups may be connected to the second dividing line 104 at different positions.

[0095] In one embodiment, referring to Figures 5 to 8, the second dividing line body 104 is connected by at least one second line body 102 between every two adjacent first line bodies 101. This ensures that the number of second line bodies 102 along the extension of the dividing line is sufficient and their distribution density is relatively uniform, which helps to ensure the structural strength of the buffer zone 120, thereby ensuring the structural stability of the conductive mesh 100.

[0096] Referring to Figures 5, 6, and 8, for each second line 102 connected to the second boundary line 104, each second line 102 is positioned in the middle of the region between two adjacent first line 101s. It is understood that "middle" does not refer to the exact midpoint, but rather the area near the midpoint. In this embodiment, the second line 102 is positioned in the middle of the boundary line between two adjacent first line 101s, ensuring sufficient offset between the connection points of the first line 101s and the second line 102, thereby ensuring the force distribution effect of the lines in the buffer zone 120. This method is particularly suitable when the line widths of the second line 102 and the first line 101 are comparable, because in this case, sufficient offset ensures uniform stress distribution, which is beneficial for maintaining the structural stability of the conductive mesh 100.

[0097] Of course, the second wire 102 connected to the second dividing line 104 can also be positioned close to the first wire 101, as shown in Figure 6. This shortens the force transmission path from the first wire 101 to the second wire 102. When the second wire 102 has sufficient structural strength, it can effectively help the first wire 101 absorb external forces, thereby ensuring the connection stability between the main body area 110 and the pin area 130.

[0098] Without loss of generality, the second dividing line 104 connects a second line 102 between every two adjacent first lines 101. That is, the spacing between two second lines 102 is roughly the same as the spacing between two first lines 101, which helps to improve the uniformity of the grid distribution, thereby improving the uniformity of stress distribution and ensuring the structural stability of the conductive grid 100. Of course, in other embodiments, the second dividing line 104 may also connect more than one second line 102 between every two adjacent first lines 101, such that the distribution density of the second lines 102 is greater than the distribution density of the first lines 101.

[0099] In one embodiment, referring to Figure 5, the buffer zone 120 is formed with multiple rows of second wires 102. The position of the third wire 103 connected to one of the adjacent rows of second wires 102 is staggered from the position connected to the second wires 102 connected to the other adjacent row. Thus, by sequentially and alternately arranging multiple rows of wires, the buffer zone 120 achieves further stress dispersion. The load can be evenly distributed in both the extension directions of the second wires 102 and the third wires 103, further reducing the risk of excessive local stress and helping to prevent the wires in the buffer zone 120 from floating away or breaking, thereby ensuring the structural stability of the conductive wires.

[0100] Furthermore, in this embodiment, the second wire 102 is arranged in at least four rows, which can effectively disperse the stress between the pin area 130 and the main body area 110, reduce the stress on the wires of the buffer zone 120, and thus prevent the wires of the buffer zone 120 from floating or breaking. Of course, in other embodiments, if the requirements for the use of the conductive mesh 100 can be met, the second wire 102 can also be arranged in two or three rows.

[0101] Furthermore, for both sides of the third wire 103, each of the second wires 102 on one side is centrally located in the region between two adjacent second wires 102 on the other side. Similarly, this ensures that the second wires 102 on both sides of the third wire 103 have sufficient offset, thereby guaranteeing the force dispersion effect of the buffer zone 120. Without loss of generality, between each pair of adjacent second wires 102 on one side, the third wire 103 is connected to a second wire 102. Thus, the spacing between the second wires 102 on opposite sides of the third wire 103 is relatively uniform, which helps improve the uniformity of the mesh distribution, thereby improving the uniformity of stress distribution and ensuring the structural stability of the conductive mesh 100. Of course, in other embodiments, the second wires 102 on both sides of the third wire 103 can also be configured with different distribution densities.

[0102] In one embodiment, referring to Figure 6, the line width of the second line body 102 is greater than the line width of the first line body 101. Thus, by increasing the line width of the second line body 102, its resistance to external forces can be improved, making it less prone to deformation and thus helping to prevent breakage, thereby ensuring the structural stability of the conductive mesh 100.

[0103] Furthermore, in this embodiment, the linewidth of the second line body 102 is at least twice the linewidth of the first line body 101. This ensures that the second line body 102 possesses sufficient strength to guarantee its resistance to deformation, thereby ensuring the structural stability of the conductive mesh 100. Additionally, it should be noted that the linewidth of the second line body 102 should be less than or equal to the line spacing between two adjacent second line bodies 102. Of course, in other embodiments, the linewidth of the second line body 102 can also be 1.5 times or 1.8 times the linewidth of the first line body 101.

[0104] In one embodiment, the distance between the pin area 130 and the second boundary line 104 is greater than or equal to 8 mm. This ensures that the buffer zone 120 covers the high-risk area between the pin area 130 and the main body area 110, which is the area where the wire is prone to breakage. The mesh of the buffer zone 120 can disperse stress in this high-risk area, preventing structural damage at the connection between the pin area 130 and the main body area 110, thus ensuring the structural stability of the conductive mesh 100. Of course, in other embodiments, this distance can be adjusted to less than 8 mm, provided that the structural stability of the conductive mesh 100 is ensured.

[0105] In one embodiment, referring to Figure 5, both the main body region 110 and the buffer zone 120 are constructed to form multiple rows of rectangular grids. In this case, the line width of the second line body 102 can be set to be comparable to (equal to or approximately equal to) the line width of the first line body 101, and the line spacing between two adjacent second line bodies 102 can also be comparable to the line spacing between two adjacent first line bodies 101. This helps to ensure that a transparent visual effect can also be formed in the buffer zone 120, thereby ensuring the applicability of the conductive grid 100 in fields such as transparent antennas and touch screens. Specifically, a row of first line bodies 101 forms multiple grids, and a row of second line bodies 102 also forms multiple grids. The number of grids formed by a row of second line bodies 102 and a row of first line bodies 101 is comparable. This allows the second line bodies 102 to disperse stress, ensuring the structural stability of the conductive grid 100, while also ensuring that the grid size formed by the second line bodies 102 is appropriate, so that a transparent visual effect can also be formed in the buffer zone 120. Furthermore, the spacing between each second line body 102 and its two adjacent first lines body 101 is also approximately equal, thereby ensuring a uniform distribution of stress. Even further, the lines in the main body region 110 and the buffer zone 120, as well as the second boundary line body 104, are all configured as preset lines, ensuring consistency in the lines of the grid region of the conductive mesh 100, facilitating the processing and shaping of the conductive mesh 100.

[0106] In one embodiment, referring to Figure 6, the main body region 110 forms multiple rows of rectangular grids, while the buffer zone 120 forms only one row of rectangular grids. The line width of the second line body 102 in the buffer zone 120 is greater than the line width of the line body in the main body region 110, and each second line body 102 is offset from a first line body 101 by a small displacement. This ensures that the second line bodies 102 are evenly distributed on the same side of the corresponding first line body 101 and are positioned close to the corresponding first line body 101. In this way, the force on the first line body 101 can be transmitted to the structurally stronger second line body 102 more quickly. By absorbing the energy of external forces through the second line body 102, it is beneficial to prevent line breakage at the connection between the main body region 110 and the pin region 130. If the length of the second line body 102 is greater than 8 mm, it can effectively cover the area between the main body region 110 and the pin region 130 that is prone to line breakage. Furthermore, the lines of the main body 110 and the second dividing line 104 are configured as preset lines, and the second line 102 of the buffer zone 120, apart from the ratio of line width to line thickness, can also have other features such as line thickness and cross-sectional shape set with reference to the preset lines.

[0107] In one embodiment, referring to Figures 7 and 8, the main body region 110 forms a rhomboid grid. The lines of the buffer zone 120 can be constructed to form a rhomboid grid as arranged in the main body region 110. Alternatively, the buffer zone 120 can be provided with multiple evenly spaced and parallel second lines 102. The second lines 102 and the lines in one direction of the main body region 110 are inclined in the same direction to form a parallelogram grid. Without loss of generality, the lines of the main body region 110 and the second dividing line 104 are configured as preset lines. The lines of the buffer zone 120 can also be configured as lines, or, except for the ratio of line width to line thickness, other features such as line thickness and cross-sectional shape can be set with reference to the preset lines.

[0108] It should be noted that, unless otherwise specified, the range values ​​mentioned in this invention include the endpoint values ​​at both ends.

[0109] This invention also proposes a transparent flexible circuit board, including the aforementioned conductive mesh. Therefore, this transparent flexible circuit board adopts all the technical solutions of all the above embodiments and possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here. The structure of this transparent flexible circuit board is shown in Figure 4, including a substrate 210, a conductive mesh 100, and a cover layer 220 stacked sequentially. The conductive mesh 100 is bonded to the substrate 210 and the cover layer 220 respectively by an adhesive layer 230.

[0110] The present invention also proposes an electronic device, including the aforementioned conductive mesh, which also adopts all the technical solutions of all the above embodiments, and therefore has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0111] In one embodiment, the electronic device is configured as a head-mounted display device. An antenna structure is disposed on the lens of the head-mounted display device. The lens of the head-mounted display device is also disposed on at least one of the antenna structure, an electrochromic film, and an electrically heated film. At least one of the antenna structure, electrochromic film, and electrically heated film includes the conductive mesh. The antenna structure, electrochromic film, and electrically heated film may completely cover the lens of the head-mounted display device or may only partially cover it.

[0112] Referring to Figure 9, without loss of generality, for the antenna structure, the main body region 110, the buffer zone 120, and the pin region 130 are arranged in a ring shape and distributed sequentially from the inside out. The pin region 130 is located near the edge of the lens to facilitate concealment within the lens frame. This effectively utilizes the peripheral area of ​​the lens while ensuring that the signal transmission path between the pins of the pin region 130 and the lines in the grid area is as short as possible. Furthermore, the overall ring-shaped structure of the antenna can shield external electromagnetic interference to a certain extent, protect the internal circuitry from external noise, help reduce the impact of electromagnetic radiation generated by the antenna itself on the external environment, and improve the antenna's directivity and gain characteristics, thereby enhancing its ability to combat multipath effects.

[0113] Of course, in other embodiments, the conductive mesh 100 can also be configured on the touch screen or electromagnetic shielding structure of an electronic device, or on the display screen of a HUD display device, i.e., on the windshield of a vehicle.

[0114] It is understandable that the conductive meshes in the above structures can take the same form to improve the standardization of materials, or they can take different forms to better adapt to different functions.

[0115] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing a conductive mesh, characterized in that, include: Cover the surface of the conductor with a dry film; The dry film is exposed and a portion of it is removed by a developer, leaving a pre-set dry film grid that corresponds to the pre-formed conductive grid. A first etching process is performed on the exposed area of ​​the conductor, with the vertical etching rate being lower than the lateral etching rate, to form a conductive mesh; wherein the cross-section of the conductive mesh formed in this step is trapezoidal in shape, the trapezoidal shape having a first bottom near the dry film and a second bottom away from the dry film, the width of the first bottom being greater than the width of the second bottom. After stripping the preset dry film mesh, the conductive mesh is micro-etched through a second etching process; wherein, the width difference between the first bottom and the second bottom of the conductive mesh after this step is smaller, and the cross-section of the resulting conductive mesh line is rectangular in shape.

2. The method for preparing the conductive mesh as described in claim 1, characterized in that, The etching agents used in the first etching process include copper ions and hydrochloric acid.

3. The method for preparing the conductive mesh as described in claim 1, characterized in that, The etching agents used in the second etching process include copper ions, hydrogen peroxide, and sulfuric acid.

4. The method for preparing the conductive mesh as described in claim 1, characterized in that, The width of the preset dry film mesh is 50% to 80% larger than the width of the preformed conductive mesh.

5. The method for preparing the conductive mesh as described in claim 4, characterized in that, The width of the preset dry film mesh is 60% to 70% larger than the width of the preformed conductive mesh.

6. The method for preparing a flexible circuit board as described in claim 1, characterized in that, The step prior to the step of coating the surface of the conductor with a dry film includes the following step: The surface of the conductor is micro-etched through a third etching process.

7. The method for preparing a flexible circuit board as described in claim 6, characterized in that, The etching agents used in the third etching process include copper ions, hydrogen peroxide, and sulfuric acid.

8. A conductive mesh, characterized in that, It is prepared by the method for preparing the conductive mesh according to any one of claims 1 to 7.

9. The conductive mesh as described in claim 8, characterized in that, The ratio of the line thickness to the line width of the conductive mesh is greater than or equal to 1.

10. The conductive mesh as claimed in claim 9, characterized in that, The line width of the conductive mesh is less than 10 micrometers; And / or, the line thickness of the conductive mesh is 6 micrometers to 12 micrometers; And / or, the ratio of the line thickness to the line width of the conductive mesh is greater than or equal to 1.

4.

11. A transparent flexible circuit board, characterized in that, Includes the conductive mesh as described in any one of claims 8 to 10.

12. An electronic device, characterized in that, Includes the conductive mesh as described in any one of claims 8 to 10.

13. The electronic device as claimed in claim 10, characterized in that, The electronic device is configured as a head-mounted display device, and the lenses of the head-mounted display device are provided with at least one of an antenna structure, an electrochromic film, and an electroheating film, wherein at least one of the antenna structure, the electrochromic film, and the electroheating film includes the conductive mesh. And / or, the electronic device includes a touch screen, the touch screen including the conductive mesh; And / or, the electronic device has an electromagnetic shielding structure, the electromagnetic shielding structure including the conductive mesh.

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