Methods for fabricating metal meshes and antennas

Abstract

This disclosure provides a method for fabricating a metal mesh and a method for fabricating an antenna, belonging to the field of electronic device technology. The method for fabricating the metal mesh includes: providing a substrate; forming a dielectric layer on the substrate; and using an inductively coupled plasma (ICP) device to dry-etch the dielectric layer to form a mesh-like groove.

Description

Technical Field

[0001] This disclosure belongs to the field of electronic device technology, specifically relating to a method for preparing a metal mesh and a method for preparing an antenna. Background Technology

[0002] Currently, the linewidth of micro / nano fabrication processes commonly used in the glass-based semiconductor industry is around 2-3 μm. However, some thin-film displays and sensors, such as transparent antennas or radio frequency (RF) devices, have higher requirements for linewidth in micro / nano fabrication. The former mainly uses narrow-linewidth metal meshes as signal transmitting and receiving units, while the latter uses narrower channel lengths in RF devices to achieve higher cutoff frequencies. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a method for preparing a metal mesh and a method for preparing an antenna.

[0004] In a first aspect, embodiments of this disclosure provide a method for preparing a metal mesh, comprising:

[0005] Provide substrates;

[0006] A dielectric layer is formed on the substrate, and the dielectric layer is dry etched using an inductively coupled plasma device to form a grid-like groove.

[0007] The dielectric layer includes a first dielectric layer and a second dielectric layer stacked together; the step of forming the dielectric layer on the substrate and forming a grid-like groove by dry etching of the dielectric layer using an inductively coupled plasma device includes:

[0008] The first dielectric layer is formed on the substrate.

[0009] The second dielectric layer is formed on the side of the first dielectric layer that is away from the substrate.

[0010] A first photoresist layer is formed on the side of the second dielectric layer opposite to the first dielectric layer, and the first photoresist layer is exposed and developed to form a first grid pattern.

[0011] The second dielectric layer is dry-etched using an inductively coupled plasma (ICP) device to remove the exposed material of the second dielectric layer and form a second mesh pattern. The second mesh pattern is used as a mask to dry-etch the first dielectric layer using an ICP device to remove the exposed material of the first dielectric layer and form a third mesh pattern. The second mesh pattern and the third mesh pattern are stacked to form the mesh-like groove.

[0012] Remove the remaining first photoresist layer.

[0013] The first dielectric layer comprises an organic material, and the etching gas used to etch the first dielectric layer is oxygen.

[0014] The organic material includes any one of polyimide, epoxy resin, acrylic, polyester, photoresist, polyacrylate, polyamide, and siloxane.

[0015] The thickness of the first dielectric layer is 2μm-5μm.

[0016] The second dielectric layer comprises an inorganic material; the etching gas used to etch the second dielectric layer is tetrafluoromethane.

[0017] The inorganic material includes any one of silicon nitride, silicon oxide, and silicon oxynitride.

[0018] The thickness of the second dielectric layer is 50nm-400nm.

[0019] The step of forming the first dielectric layer on the substrate includes:

[0020] A first dielectric material is formed on the substrate by a coating process, and then cured at high temperature to form a first dielectric layer.

[0021] The step of forming the second dielectric layer on the side of the first dielectric layer opposite to the substrate includes:

[0022] The second dielectric layer is formed on the side of the first dielectric layer away from the substrate using a plasma chemical vapor deposition apparatus.

[0023] The method for preparing the metal mesh further includes, before forming the dielectric layer on the substrate, the following steps:

[0024] A first metal thin film is formed on the substrate, and the first metal thin film is used as a seed layer;

[0025] After forming the mesh-like grooves, the method further includes: removing the second mesh pattern;

[0026] The seed layer is electroplated to allow the growth of a first metal film within the groove;

[0027] The dielectric layer and the first metal film on the side of the dielectric layer near the substrate are removed to form a metal mesh.

[0028] The material of the first metal film includes copper or silver.

[0029] The method for preparing the metal mesh further includes, after forming the mesh-shaped grooves, the following steps:

[0030] Remove the second grid pattern;

[0031] A first metal film is formed on the side of the grid-like groove away from the substrate, and the first metal film is used as a seed layer.

[0032] The seed layer is electroplated to allow the first metal film to grow. The grown first metal film, located outside the grid-like groove, is then removed to form a metal grid.

[0033] The material of the first metal film includes copper or silver.

[0034] The width of the mesh-like groove is no greater than 1.5 μm.

[0035] Secondly, embodiments of this disclosure provide a method for fabricating an antenna, comprising:

[0036] A first dielectric substrate is provided, the first dielectric substrate including a first surface and a second surface disposed opposite to each other along its thickness direction;

[0037] A reference electrode layer is formed on the first surface of the first dielectric substrate;

[0038] A radiating portion is formed on the second surface of the first dielectric substrate; wherein...

[0039] At least one of the reference electrode layer and the radiating portion includes a metal mesh, which is prepared using any of the preparation methods described above.

[0040] The reference electrode layer and the radiating portion are metal meshes, and the orthographic projections of the cutout portions of the reference electrode layer and the radiating portion on the first dielectric substrate overlap.

[0041] The first dielectric substrate includes a first sub-dielectric layer, a first adhesive layer and a second sub-dielectric layer stacked together, the reference electrode layer is formed on the side of the first sub-dielectric layer opposite to the first adhesive layer, and the radiating portion is disposed on the side of the second sub-dielectric layer opposite to the first adhesive layer.

[0042] The material of the first sub-dielectric layer and / or the second sub-dielectric layer includes polyimide or polyethylene terephthalate.

[0043] The first dielectric substrate is a single-layer structure, and its material includes polyimide or polyethylene terephthalate. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of an exemplary thin-film sensor.

[0045] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the thin-film sensor along the AA' direction.

[0046] Figure 3 This is a top view of the grid-like groove according to an embodiment of the present disclosure.

[0047] Figure 4 for Figure 3 The diagram shows a cross-sectional structure of the grid-like groove in the BB' direction.

[0048] Figure 5 This is a flowchart illustrating a first example of a method for preparing a metal mesh according to an embodiment of the present disclosure, specifically a method for forming mesh-shaped grooves.

[0049] Figure 6 This is a test diagram of a first example of forming a mesh-shaped groove in a method for preparing a metal mesh according to an embodiment of the present disclosure.

[0050] Figure 7 This is a test diagram of a second example of forming a mesh-like groove in the method for preparing a metal mesh according to an embodiment of this disclosure.

[0051] Figure 8 This is a test diagram of a third example of forming a mesh-like groove in the method for preparing a metal mesh according to an embodiment of this disclosure.

[0052] Figure 9 This is a top view of a metal mesh according to an embodiment of the present disclosure.

[0053] Figure 10 for Figure 9 The diagram shows a cross-sectional structure of the metal mesh along the CC' direction.

[0054] Figure 11 This is a flowchart illustrating a first example of a method for preparing a metal mesh according to an embodiment of the present disclosure.

[0055] Figure 12 This is a test diagram of a fourth example of forming a mesh-like groove in the method for preparing a metal mesh according to an embodiment of this disclosure.

[0056] Figure 13 This is a test diagram of a fifth example of forming a mesh-shaped groove in the method for preparing a metal mesh according to an embodiment of this disclosure.

[0057] Figure 14 This is a test diagram of a sixth example of forming a mesh-shaped groove in the method for preparing a metal mesh according to an embodiment of the present disclosure.

[0058] Figure 15 This is a cross-sectional view of an antenna according to an embodiment of this disclosure.

[0059] Figure 16 This is another cross-sectional view of the antenna according to an embodiment of this disclosure. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0062] Figure 1 This is a schematic diagram of an exemplary thin-film sensor. Figure 2 for Figure 1 The diagram shows a cross-sectional view of the thin-film sensor along the AA' direction. Figure 1 and Figure 2 As shown, the thin-film sensor includes: a substrate 100, which has a first surface and a second surface, namely an upper surface and a lower surface, disposed opposite to each other; a first conductive layer 101 and a second conductive layer 102 are respectively located on the first surface and the second surface of the substrate 100. Taking the thin-film sensor as a transparent antenna as an example, the first conductive layer 101 can be a radiating layer, and the second conductive layer 102 can be a grounding layer. The radiating layer can serve as a receiving unit of the antenna structure or as a transmitting unit of the antenna structure.

[0063] To ensure good light transmittance of the first conductive layer 101 and the second conductive layer 102, both layers need to be patterned. For example, the first conductive layer 101 can be constructed using a grid of metal lines, and the second conductive layer 102 can also be constructed using a grid of metal lines. It is understood that the first conductive layer 101 and the second conductive layer 102 can also be constructed using other patterned structures, such as block electrodes with rhomboid or triangular patterns, which will not be listed here. Figure 1 It can be seen that the first conductive layer 101 and the second conductive layer 102, i.e., the grid lines, are not evenly distributed on both surfaces of the substrate 100. Each grid line is composed of an electrically connected metal mesh. Due to the material and forming process of the metal mesh, the line width of the metal mesh is relatively wide, which seriously affects the light transmittance of the thin-film sensor, thereby affecting the user experience.

[0064] In some examples, to achieve a narrower linewidth metal mesh 501, a first dielectric layer 200 and a second dielectric layer 300 can be sequentially formed on the substrate 100. The first dielectric layer 200 serves as a buffer layer, and the second dielectric layer 300 serves as a hard mask layer. Wet etching is then performed to form a mesh-like groove 201, and metal material is formed within these grooves, thus creating the metal mesh 501. However, due to the different material types and thicknesses of the buffer layer and the hard mask layer, the vertices of the rhombuses in the mesh-like grooves 201 will be "passivated" to varying degrees after the etching process, forming rounded corners. The radius of these rounded corners is the etching loss radius. The linewidth at the intersections of the mesh-like grooves will increase to varying degrees, thus affecting the antenna gain.

[0065] It should also be noted that the aforementioned metal mesh 501 is not limited to antenna structures; it can also be used in touch panels as touch electrodes. Of course, the metal mesh 501 can also be used in various metal wires, which will not be listed here.

[0066] In a first aspect, to address the aforementioned problems, this disclosure provides a method for preparing a metal mesh. The method includes: providing a substrate; forming a dielectric layer on the substrate; and using an inductively coupled plasma (ICP) device to dry-etch the dielectric layer to form a mesh-like groove. The mesh-like groove is used for subsequent metal mesh formation.

[0067] In this embodiment of the disclosure, dry etching of the dielectric layer is performed using an inductively coupled plasma device. Compared with the wet etching method described above, it has better anisotropy and less impact on etching radius loss. This helps to form a metal mesh with a narrower linewidth, thereby reducing the impact on antenna gain.

[0068] In some examples, the substrate in this disclosure can be a glass substrate or a flexible thin film. The flexible thin film material can be at least one of COP film, polyimide (PI), or polyethylene terephthalate (PET). This disclosure describes an example where the substrate is glass-based.

[0069] In some examples, the dielectric layer may include a first dielectric layer and a second dielectric layer. Specifically, the first dielectric layer 200 may be a buffer layer, and the second dielectric layer may be a hard mask layer. Further, the buffer layer includes, but is not limited to, organic materials, such as polyimide, epoxy resin, acrylic, polyester, photoresist, polyacrylate, polyamide, siloxane, and other resin-based materials. The hard mask layer includes, but is not limited to, inorganic materials, metal oxides, and metal materials. Inorganic materials include silicon nitride (SiNx), silicon oxide (SiO2), and silicon oxynitride (SiON); metal materials include copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag); metal oxides include indium tin oxide (ITO). In this embodiment, an inorganic material is used as an example of the material of the hard mask layer.

[0070] The following details the steps for forming the mesh-like grooves 201 when different materials and thicknesses are selected for the buffer layer and the hard mask layer.

[0071] Figure 3 This is a top view of the mesh-like groove according to an embodiment of the present disclosure; Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the grid-like groove in the BB' direction; Figure 5 This is a flowchart illustrating a first example of forming mesh-shaped grooves in a method for preparing a metal mesh according to an embodiment of this disclosure; as shown... Figure 3-5 As shown, in the first example: S11, an epoxy resin with a thickness of 4μm is coated on the substrate 100 as a buffer layer, and the buffer layer is cured at high temperature.

[0072] S12. On the side of the buffer layer away from the substrate 100, a silicon nitride layer with a thickness of about 200 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0073] S13. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first grid pattern 401.

[0074] S14. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0075] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 6 This is a test diagram illustrating a first example of forming mesh-shaped grooves in a method for preparing a metal mesh according to an embodiment of this disclosure; as shown... Figure 6 As shown, after testing, the final etching loss radius of the first example is approximately 0.77 μm, which meets the process requirement of less than 1.5 μm.

[0076] The second example follows the same process as the first example, except that the thickness of the buffer layer and the material of the hard mask layer differ. The specific steps for the second example are as follows:

[0077] S21. A 3.3 μm thick epoxy resin is coated on the substrate 100 as a buffer layer, and the buffer layer is cured at high temperature.

[0078] S22. On the side of the buffer layer away from the substrate 100, a silicon oxide layer with a thickness of about 300 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0079] S23. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first grid pattern 401.

[0080] S24. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0081] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 7 This is a test diagram illustrating a second example of forming mesh-like grooves in the method for preparing a metal mesh according to an embodiment of this disclosure; as shown... Figure 7 As shown, after testing, the final etching loss radius of the second example is approximately 1.18 μm, which meets the process requirement of less than 1.5 μm.

[0082] The third example follows the same process as the first example, except that the thickness of the buffer layer and the material of the hard mask layer differ. The specific steps for the third example are as follows:

[0083] S31. A 5.5 μm thick epoxy resin is coated on the substrate 100 as a buffer layer, and the buffer layer is cured at high temperature.

[0084] S32. On the side of the buffer layer away from the substrate 100, a silicon oxynitride (a mixture of silicon oxide and silicon nitride) with a thickness of about 200 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0085] S33. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first grid pattern 401.

[0086] S34. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0087] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 8 This is a test diagram illustrating a third example of forming mesh-like grooves in the method for preparing a metal mesh according to an embodiment of this disclosure; as shown... Figure 8 As shown, after testing, the final etching loss radius of the third example is approximately 0.76 μm, which meets the process requirement of less than 1.5 μm.

[0088] In some examples, the method for fabricating a thin-film sensor according to embodiments of this disclosure includes not only the step of forming a grid-like groove 201 on a substrate 100, but also the step of forming a metal grid 501. The material of the metal grid 501 includes, but is not limited to, copper, silver, etc. Specific examples will be described below.

[0089] Fourth example: Figure 9 This is a top view of a metal mesh according to an embodiment of the present disclosure. Figure 10 for Figure 9 The diagram shows a cross-sectional structure of the metal mesh along the CC' direction. Figure 11 This is a flowchart illustrating a first example of a method for preparing a metal mesh according to an embodiment of the present disclosure; as shown... Figure 9-11 As shown, the fabrication method of the fourth example includes: S41, forming a first metal thin film 500 on a substrate 100. The process for forming the first metal thin film 500 includes, but is not limited to, magnetron sputtering. The material of the first metal thin film 500 is copper, and the thickness is 300 nm.

[0090] S42. On the side of the first metal film layer away from the substrate 100, an epoxy resin with a thickness of 4.9 μm is coated as a buffer layer, and the buffer layer is cured at high temperature.

[0091] S43. On the side of the buffer layer away from the substrate 100, a silicon nitride layer with a thickness of about 300 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0092] S44. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first mesh pattern 401.

[0093] S45. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0094] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 12 This is a test diagram illustrating a fourth example of forming mesh-like grooves in the method for preparing a metal mesh according to embodiments of this disclosure; as shown... Figure 12 As shown, the fourth example ultimately resulted in an etching loss radius of approximately 0.82 μm, which meets the process requirement of less than 1.5 μm. However, it should be noted that the etching time for the buffer layer with oxygen should not be too long, as this will not only cause a loss in etching radius but also lead to oxidation of the seed layer.

[0095] S46. Remove the second grid pattern.

[0096] S47. The first metal film layer is used as a seed layer, and the seed layer is electroplated.

[0097] In some examples, step S47 specifically includes placing one side of the substrate 100 with the grid-like grooves 201 onto an electroplating machine carrier, pressing on an electric pad, immersing it in a via-filling electroplating tank (using a special via-filling electrolyte), applying current, and maintaining the electroplating solution flowing continuously and rapidly on the surface of the substrate 100. On the sidewalls of the grooves, cations in the electroplating solution gain electrons and become atoms, depositing on the sidewalls. Using a specially formulated via-filling electrolyte, high-speed deposition of metallic copper (deposition rate 0.5-3 μm / min) can be achieved primarily in the grooves. Over time, the metallic copper on the sidewalls of the grooves gradually thickens, eventually completely filling the grooves. Finally, the substrate 100 is removed and rinsed with deionized water.

[0098] S48. Remove the material of the first metal film layer on the substrate 100, excluding the metal material in the groove, to form a metal mesh 501.

[0099] The fifth example follows the same process as the fourth example, except that the thickness of the buffer layer and the material of the hard mask layer differ from the first example. The specific steps of the third example are as follows:

[0100] S51. A first metal thin film 500 is formed on the substrate 100. The process for forming the first metal thin film 500 includes, but is not limited to, magnetron sputtering. The material of the first metal thin film 500 is copper, and the thickness is 300 nm.

[0101] S52. On the side of the first metal film layer away from the substrate 100, an epoxy resin with a thickness of 3.3 μm is coated as a buffer layer, and the buffer layer is cured at high temperature.

[0102] S53. On the side of the buffer layer away from the substrate 100, a silicon oxynitride (a mixture of silicon nitride and silicon oxide) with a thickness of about 100 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0103] S54. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first grid pattern 401.

[0104] S55. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0105] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 13 This is a test diagram illustrating a fifth example of forming mesh-shaped grooves in the method for preparing a metal mesh according to embodiments of this disclosure; as shown... Figure 13 As shown, testing revealed that the final etching loss radius of the fifth example was approximately 0.60 μm, meeting the process requirement of less than 1.5 μm. However, it is important to note that the etching time for the buffer layer using oxygen should not be too long, as this will not only cause a loss in etching radius but also lead to oxidation of the seed layer.

[0106] S56. Remove the second grid pattern.

[0107] S57. The first metal film layer is used as a seed layer, and the seed layer is electroplated.

[0108] In some examples, step S57 specifically includes placing one side of the substrate 100 with the grid-like grooves 201 onto an electroplating machine carrier, pressing on an electric pad, immersing it in a via-filling electroplating tank (using a special via-filling electrolyte), applying current, and maintaining the electroplating solution flowing continuously and rapidly on the surface of the substrate 100. On the sidewalls of the grooves, cations in the electroplating solution gain electrons and become atoms, depositing on the sidewalls. Using a specially formulated via-filling electrolyte, high-speed deposition of metallic copper (deposition rate 0.5-3 μm / min) can be achieved primarily in the grooves. Over time, the metallic copper on the sidewalls of the grooves gradually thickens, eventually completely filling the grooves. Finally, the substrate 100 is removed and rinsed with deionized water.

[0109] S58. Remove the material of the first metal film layer on the substrate 100, excluding the metal material in the groove, to form a metal mesh 501.

[0110] The sixth example follows the same process as the fourth example, except that the thickness of the buffer layer and the material of the hard mask layer differ from the first example. The specific steps of the third example are as follows:

[0111] S61. A first metal thin film 500 is formed on the substrate 100. The process for forming the first metal thin film 500 includes, but is not limited to, magnetron sputtering. The material of the first metal thin film 500 is silver, and the thickness is 300 nm.

[0112] S62. On the side of the first metal film layer away from the substrate 100, an epoxy resin with a thickness of 3.3 μm is coated as a buffer layer, and the buffer layer is cured at high temperature.

[0113] S63. On the side of the buffer layer away from the substrate 100, a silicon oxynitride (a mixture of silicon nitride and silicon oxide) with a thickness of about 100 nm is deposited at high temperature using a plasma-enhanced chemical vapor deposition (PECVD) device as a hard mask layer.

[0114] S64. On the side of the hard mask layer away from the buffer layer, a first photoresist layer 400 (BFP100) is coated, and exposure and development are performed to form a first grid pattern 401.

[0115] S65. Using an inductively coupled plasma (ICP) device, the hard mask layer is dry-etched to remove the exposed hard mask layer material, forming a second mesh pattern. Using the second mesh pattern as a mask, the buffer layer is dry-etched using an ICP device to remove the exposed buffer layer material, forming a third mesh pattern 2011. The remaining first photoresist layer 400 is also removed. The second mesh pattern and the third mesh pattern 2011 are stacked to form a mesh-like groove 201.

[0116] In the inductively coupled plasma (ICP) apparatus, tetrafluoromethane (CF4) is used as the etching gas for dry etching of the hard mask layer. This etching process simultaneously etches the exposed hard mask layer material and also slightly etches the first photoresist layer 400. Next, oxygen (O2) is used as the etching gas for the buffer layer, and this etching process also etches the first photoresist layer 400. Because dry etching using an ICP apparatus exhibits better anisotropy compared to wet etching, the impact on etching radius loss is relatively small. Figure 14 A test diagram of a sixth example of the mesh-like grooves of the thin-film sensor according to embodiments of this disclosure; as shown Figure 14 As shown, the sixth example, after testing, ultimately achieved an etching loss radius of approximately 0.68 μm, which meets the process requirement of less than 1.5 μm. However, it should be noted that when etching the buffer layer with oxygen, the etching time should not be too long, as this will not only cause a loss in etching radius but also lead to oxidation of the seed layer.

[0117] S66. Remove the second grid pattern.

[0118] S67. The first metal film layer is used as a seed layer, and the seed layer is electroplated.

[0119] In some examples, step S66 specifically includes placing one side of the substrate 100 with the grid-like grooves 201 onto an electroplating machine carrier, pressing on an electric pad, immersing it in a via-filling electroplating tank (using a special via-filling electrolyte), applying current, and maintaining the electroplating solution flowing continuously and rapidly on the surface of the substrate 100. On the sidewalls of the grooves, cations in the electroplating solution gain electrons and become atoms, depositing on the sidewalls. Using a specially formulated via-filling electrolyte, high-speed deposition of metallic copper (deposition rate 0.5-3 μm / min) can be achieved primarily in the grooves. Over time, the metallic copper on the sidewalls of the grooves gradually thickens, eventually completely filling the grooves. Finally, the substrate 100 is removed and rinsed with deionized water.

[0120] S68. Remove the material of the first metal film layer on the substrate 100, excluding the metal material in the groove, to form a metal mesh 501.

[0121] Of course, in some examples, a first metal film 500 can be formed as a seed layer after the mesh-like groove 201 is formed, followed by electroplating to allow the metal material in the groove to grow, and finally the remaining first metal film 500 except for the metal material in the groove is removed to form a metal mesh 501.

[0122] Secondly, Figure 15 This is a cross-sectional view of an antenna according to an embodiment of this disclosure; as shown Figure 15 As shown, this disclosure provides a method for fabricating an antenna, which includes providing a first dielectric substrate, the first dielectric substrate including a first surface and a second surface disposed opposite to each other along its thickness direction; forming a reference electrode layer on the first surface of the first dielectric substrate; and forming a radiating portion on the second surface of the first dielectric substrate. At least one of the reference electrode layer and the radiating portion is a metal mesh, and the metal mesh can be fabricated using any of the above-described methods.

[0123] If both the reference electrode layer and the radiating part adopt a metal mesh structure, the resulting antenna is a transparent antenna. Transparent antennas can be applied to glass window systems in vehicles, trains (including high-speed trains), airplanes, buildings, etc. The transparent antenna can be fixed to the inside of the glass window (the side closer to the interior). Because transparent antennas have high optical transmittance, they do not significantly affect the transmittance of the glass window while achieving communication functions, and this type of transparent antenna is becoming a trend in aesthetically pleasing antennas. In this embodiment, the glass window includes, but is not limited to, double-glazed windows; the type of glass window can also be single-glazed, laminated, thin, or thick glass.

[0124] In this embodiment, both the reference electrode layer and the radiating portion employ metal meshes, and the orthographic projections of the cutout portions of the metal meshes on the first dielectric substrate overlap, thereby improving light transmittance. The extension directions of the first and second metal lines of the metal mesh can be perpendicular to each other, forming a directional or rectangular cutout portion. Alternatively, the extension directions of the first and second metal lines of the metal mesh can be non-perpendicular; for example, if the angle between the extension directions of the first and second metal lines is 45°, a rhomboid cutout portion is formed.

[0125] In some examples, the first dielectric substrate can be the aforementioned substrate, or it can be a separately provided dielectric substrate. In the embodiments of this disclosure, the first dielectric substrate can be a single-layer structure, and its material can be polyimide or polyethylene terephthalate. Figure 16 This is another cross-sectional view of the antenna according to an embodiment of this disclosure; as shown Figure 16As shown, in this embodiment of the present disclosure, a first sub-dielectric layer, a first adhesive layer, a second sub-dielectric layer, a second adhesive layer, and a third sub-dielectric layer are sequentially stacked on a first dielectric substrate; wherein, a reference electrode layer is disposed on the side of the first sub-dielectric layer near the first adhesive layer; and a radiating portion is disposed on the side of the second sub-dielectric layer near the second adhesive layer. The material of the first sub-dielectric layer can be polyimide or polyethylene terephthalate, and the material of the second sub-dielectric layer can also be polyimide or polyethylene terephthalate. The material of the first adhesive layer can be transparent optical adhesive.

[0126] Of course, the antenna fabrication method of this disclosure may also include steps such as forming a feed network, which will not be listed here.

[0127] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a metal mesh, comprising: Provide substrates; A dielectric layer is formed on the substrate, and the dielectric layer is dry etched using an inductively coupled plasma device to form a grid-like groove. The dielectric layer includes a first dielectric layer and a second dielectric layer stacked together, and the first dielectric layer and the second dielectric layer have different thicknesses. The material of the first dielectric layer is epoxy resin, and the thickness of the first dielectric layer is 5.5 μm.

2. The method for preparing a metal mesh according to claim 1, wherein, The step of forming a dielectric layer on the substrate and dry etching the dielectric layer using an inductively coupled plasma device to form a mesh-like groove includes: The first dielectric layer is formed on the substrate. The second dielectric layer is formed on the side of the first dielectric layer that is away from the substrate. A first photoresist layer is formed on the side of the second dielectric layer opposite to the first dielectric layer, and the first photoresist layer is exposed and developed to form a first grid pattern. The second dielectric layer is dry-etched using an inductively coupled plasma (ICP) device to remove the exposed material of the second dielectric layer and form a second mesh pattern. The second mesh pattern is used as a mask to dry-etch the first dielectric layer using an ICP device to remove the exposed material of the first dielectric layer and form a third mesh pattern. The second mesh pattern and the third mesh pattern are stacked to form the mesh-like groove. Remove the remaining first photoresist layer.

3. The method for preparing a metal mesh according to claim 2, wherein, The etching gas used to etch the first dielectric layer is oxygen.

4. The method for preparing a metal mesh according to claim 2, wherein, The second dielectric layer comprises an inorganic material; the etching gas used to etch the second dielectric layer is tetrafluoromethane.

5. The method for preparing a metal mesh according to claim 4, wherein, The inorganic material includes any one of silicon nitride, silicon oxide, and silicon oxynitride.

6. The method for preparing the metal mesh according to claim 2, wherein, The thickness of the second dielectric layer is 50nm-400nm.

7. The method for preparing a metal mesh according to claim 2, wherein, The step of forming the first dielectric layer on the substrate includes: A first dielectric material is formed on the substrate by a coating process, and then cured at high temperature to form a first dielectric layer.

8. The method for preparing a metal mesh according to claim 2, wherein, The step of forming the second dielectric layer on the side of the first dielectric layer opposite to the substrate includes: The second dielectric layer is formed on the side of the first dielectric layer away from the substrate using a plasma chemical vapor deposition apparatus.

9. The method for preparing a metal mesh according to any one of claims 2-8, wherein, Also includes: Before forming the dielectric layer on the substrate, the method further includes: A first metal thin film is formed on the substrate, and the first metal thin film is used as a seed layer; After forming the mesh-like grooves, the method further includes: removing the second mesh pattern; The seed layer is electroplated to allow the growth of a first metal film within the groove; The dielectric layer and the first metal film on the side of the dielectric layer near the substrate are removed to form a metal mesh.

10. The method for preparing a metal mesh according to claim 9, wherein, The material of the first metal film includes copper or silver.

11. The method for preparing a metal mesh according to any one of claims 2-8, wherein, Also includes: After forming the mesh-like grooves, the method further includes: Remove the second grid pattern; A first metal film is formed on the side of the grid-like groove away from the substrate, and the first metal film is used as a seed layer. The seed layer is electroplated to allow the first metal film to grow. The grown first metal film, located outside the grid-like groove, is then removed to form a metal grid.

12. The method for preparing a metal mesh according to claim 9, wherein, The material of the first metal film includes copper or silver.

13. The method for preparing a metal mesh according to any one of claims 1-8, wherein, The width of the mesh-like groove is no greater than 1.5 μm.

14. A method for manufacturing an antenna, comprising: A first dielectric substrate is provided, the first dielectric substrate including a first surface and a second surface disposed opposite to each other along its thickness direction; A reference electrode layer is formed on the first surface of the first dielectric substrate; A radiating portion is formed on the second surface of the first dielectric substrate; wherein... At least one of the reference electrode layer and the radiating portion comprises a metal mesh, which is prepared using the preparation method according to any one of claims 1-13.

15. The preparation method according to claim 14, wherein, The reference electrode layer and the radiating portion are metal meshes, and the orthographic projections of the cutout portions of the reference electrode layer and the radiating portion on the first dielectric substrate overlap.

16. The preparation method according to claim 14, wherein, The first dielectric substrate includes a first sub-dielectric layer, a first adhesive layer and a second sub-dielectric layer stacked together, the reference electrode layer is formed on the side of the first sub-dielectric layer opposite to the first adhesive layer, and the radiating portion is disposed on the side of the second sub-dielectric layer opposite to the first adhesive layer.

17. The preparation method according to claim 16, wherein, The material of the first sub-dielectric layer and / or the second sub-dielectric layer includes polyimide or polyethylene terephthalate.

18. The preparation method according to claim 16, wherein, The first dielectric substrate is a single-layer structure, and its material includes polyimide or polyethylene terephthalate.

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