Method for producing a conductive grid and method for producing a thin-film sensor

Abstract

The present disclosure provides a preparation method of a conductive grid and a preparation method of a thin film sensor, and belongs to the technical field of communication. The preparation method of the conductive grid comprises the following steps: forming a first dielectric layer on a substrate, patterning the first dielectric layer to form a plurality of first slots; forming a second dielectric layer on the side of the first dielectric layer away from the substrate and having the plurality of first slots, and patterning the second dielectric layer to form a plurality of first limiting portions; removing the first dielectric layer having the plurality of first slots, forming a third dielectric layer on the side of the second dielectric layer having the plurality of first limiting portions away from the substrate, and processing the third dielectric layer to expose the surface of the first limiting portion away from the substrate; removing the first limiting portion to form a plurality of second slots in the third dielectric layer; forming a conductive material in the second slots through an electroplating process, and forming a pattern comprising the conductive grid through a patterning process.

Description

Technical Field

[0001] The present disclosure belongs to the field of communication technology, and particularly relates to a method for preparing a conductive grid and a method for preparing a thin film sensor. Background Art

[0002] Currently, the linewidths commonly used in micro-nanofabrication processes in the glass-based semiconductor industry are around 2-3μm. However, certain thin-film display and sensor devices, such as transparent microwave devices, place even higher demands on these linewidths. These devices typically use a conductive grid as the signal transmitter and receiver. However, this grid inevitably reduces transmittance, making further improvement a key research priority. Summary of the Invention

[0003] The present disclosure aims to solve at least one of the technical problems existing in the prior art and provides a method for preparing a conductive grid and a method for preparing a thin film sensor.

[0004] In a first aspect, an embodiment of the present disclosure provides a method for preparing a conductive grid, comprising:

[0005] Providing a base substrate, forming a first dielectric layer on the base substrate, and patterning the first dielectric layer to form a plurality of first grooves;

[0006] forming a second dielectric layer on a side of the first dielectric layer having the plurality of first grooves formed therein, facing away from the base substrate, and patterning the second dielectric layer to form a plurality of first defining portions, wherein the first defining portions are hollow structures, and a sidewall of one first defining portion is only aligned with a sidewall of one first groove; removing the first dielectric layer having the plurality of first grooves formed therein, and forming a third dielectric layer on a side of the second dielectric layer having the plurality of first defining portions formed therein, facing away from the base substrate, and processing the third dielectric layer to expose surfaces of the first defining portions facing away from the base substrate;

[0007] removing the first defining portion to form a plurality of second grooves in the third dielectric layer;

[0008] A conductive material is formed in the second groove by an electroplating process, and a pattern including a conductive grid is formed by a patterning process.

[0009] Optionally, forming a conductive material in the second groove by an electroplating process includes:

[0010] forming a conductive film layer as a seed layer on a side of the second dielectric layer facing away from the substrate;

[0011] The seed layer is electroplated to form a conductive material in the second groove.

[0012] Optionally, the material of the third dielectric layer includes photoresist, OC glue or PI glue.

[0013] Optionally, forming a conductive material in the second groove by an electroplating process includes:

[0014] Before the step of forming the first dielectric layer on the base substrate, a conductive film layer is formed on the base substrate as a seed layer;

[0015] The seed layer is electroplated to form the conductive material in the second groove.

[0016] Optionally, the material of the third dielectric layer includes positive photoresist, negative photoresist or PI photoresist.

[0017] Optionally, a material of the second dielectric layer includes silicon nitride or silicon oxide.

[0018] Optionally, after forming the conductive grid, the method further includes:

[0019] A passivation layer is formed on a side of the conductive grid facing away from the substrate.

[0020] Optionally, the thickness of the first dielectric layer is 2-5 μm.

[0021] Optionally, the sidewall thickness of the first defining portion is no more than 1.5 μm.

[0022] In a second aspect, the present disclosure provides a method for preparing a thin film sensor, which includes the above-mentioned method for preparing a conductive grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an exemplary thin film sensor;

[0024] Figure 2 for Figure 1 The schematic diagram of the cross-sectional structure of the thin film sensor along the AA' direction is shown;

[0025] Figure 3 A flow chart of a method for preparing a conductive grid provided for implementation of the present disclosure;

[0026] Figure 4a A top view of an intermediate product formed in step S11 of the method for preparing a conductive grid according to an embodiment of the present disclosure;

[0027] Figure 4b A top view of an intermediate product formed in step S13 of the method for preparing a conductive grid according to an embodiment of the present disclosure;

[0028] Figure 4cA top view of an intermediate product formed in step S14 of the method for preparing a conductive grid according to an embodiment of the present disclosure;

[0029] Figure 4d A top view of an intermediate product formed in step S17 of the method for preparing a conductive grid according to an embodiment of the present disclosure;

[0030] Figure 5 A flow chart of another method for preparing a conductive grid provided for implementation of the present disclosure;

[0031] Figure 6 A flow chart of another method for preparing a conductive grid provided for the implementation of the present disclosure;

[0032] Figure 7 A flow chart of another method for preparing a conductive grid provided for the implementation of the present disclosure. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0035] It should be noted that "composition process" and "patterning" refer to the steps of forming a structure with a specific pattern, which may be a photolithography process, which includes one or more steps of forming a material layer, applying photoresist, exposing, developing, etching, and photoresist stripping; of course, "composition process" and "patterning" may also be other processes such as imprinting process and inkjet printing process.

[0036] Figure 1 is a schematic structural diagram of an exemplary thin film sensor; Figure 2 for Figure 1The cross-sectional structure diagram of the thin film sensor along the AA' direction is shown in FIG. Figure 1 and Figure 2 As shown, the thin film sensor includes: a base substrate 100 having a first surface and a second surface (i.e., an upper surface and a lower surface) disposed opposite each other; a first conductive layer 101 and a second conductive layer 102 located on the first and second surfaces of the base substrate 100, respectively. For example, in the case of a thin film sensor as a transparent antenna, 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 either a receiving element or a transmitting element of the antenna structure.

[0037] In order to ensure that the first conductive layer 101 and the second conductive layer 102 have good light transmittance, the first conductive layer 101 and the second conductive layer 102 need to be patterned. For example, the first conductive layer 101 can be composed of grid lines made of metal materials, and the second conductive layer 102 can also be composed of grid lines made of metal materials. It is understandable that the first conductive layer 101 and the second conductive layer 102 can also be composed of structures with other patterns, such as block electrodes with diamond, triangle and other patterns, which are not listed here one by one. Figure 1 As can be seen, the first conductive layer 101 and the second conductive layer 102, i.e., the grid lines, are not disposed across the entire surface of both surfaces of the base substrate 100. Each grid line is formed by an electrically connected conductive mesh. Due to the material and formation process of the conductive mesh, the line width of the conductive mesh is relatively wide, significantly affecting the light transmittance of the thin-film sensor, thereby impacting the user experience.

[0038] It should also be noted that the conductive mesh is not limited to being used in antenna structures, but can also be used in touch panels as touch electrodes. Of course, the conductive mesh can also be used in various metal wires, which are not listed here.

[0039] To address the aforementioned technical issues, the present disclosure provides a method for fabricating a conductive mesh and a method for fabricating a thin film sensor. While the present disclosure utilizes the conductive mesh as a receiving element and / or transmitting element in an antenna as an example, it should be understood that this does not limit the scope of protection of the present disclosure.

[0040] Figure 3 A flow chart of a method for preparing a conductive grid provided for the implementation of the present disclosure is provided. Figure 4a This is a top view of an intermediate product formed in step S11 of the method for preparing a conductive grid according to an embodiment of the present disclosure. Figure 4b This is a top view of the intermediate product formed in step S13 of the method for preparing the conductive grid according to an embodiment of the present disclosure. Figure 4cThis is a top view of the intermediate product formed in step S14 of the method for preparing the conductive grid according to an embodiment of the present disclosure. Figure 4d FIG. 1 is a top view of an intermediate product formed in step S17 of the method for preparing a conductive grid according to an embodiment of the present disclosure. Figure 3 、 Figure 4a-4d As shown, in a first aspect, an embodiment of the present disclosure provides a method for preparing a conductive grid, comprising:

[0041] S11, providing a base substrate 11, forming a first dielectric layer 12 on the base substrate 11, and patterning the first dielectric layer 12 to form a plurality of first slots B (such as Figure 4a ).

[0042] Among them, the base substrate 11 can be a flexible substrate or can be set to be rigid. The specific performance of the base substrate 11 can be determined according to actual needs. In addition, the base substrate 11 can be a single-layer structure or a multi-layer structure. For example, the base substrate 11 may include multiple film layers such as a polyimide layer, a buffer layer, and a polyimide layer stacked in sequence, wherein the buffer layer can be made of materials such as silicon nitride and silicon oxide to achieve the effect of blocking water and oxygen and blocking alkaline ions; it should be noted that the structure of the base substrate 11 is not limited to this and can be determined according to actual needs. In some examples, when the base substrate 11 is a flexible film, the flexible film material can be at least one of COP film, polyimide (PI) or polyethylene terephthalate (PET). At this time, in S11, the flexible COP film can be bonded to the glass substrate through transparent optical glue (OCA glue), and then the glass substrate with the COP film formed is cleaned. The material of the first dielectric layer includes but is not limited to positive photoresist, negative photoresist, PI (polyimide) glue, optically transparent glue, etc. The thickness of the first dielectric layer 12 can be selected according to the actual situation. Preferably, the thickness of the first dielectric layer 12 is in the range of 2-5 μm.

[0043] The thickness of the first dielectric layer 12 is the thickness of the conductive grid lines to be formed, and the width of the first dielectric layer 12 is the line spacing of the conductive grid lines to be formed.

[0044] S12 , forming a second dielectric layer 13 on a side of the first dielectric layer 12 having the plurality of first grooves B formed therein, the side facing away from the base substrate 11 .

[0045] The material of the second dielectric layer 13 includes, but is not limited to, inorganic materials, metal oxides, and metal materials. Inorganic materials include silicon nitride (SiNx), silicon oxide (SiO2), silicon oxynitride (SiON), and the like; metal materials include copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag); and metal oxides include indium tin oxide (ITO). In the embodiment of the present disclosure, the second dielectric layer 13 is made of an inorganic material as an example.

[0046] When the material of the second dielectric layer 13 is an inorganic material, the second dielectric layer 13 can be formed on the side of the first dielectric layer 12 with multiple first grooves B formed away from the substrate by plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition, electron cyclotron resonance chemical vapor deposition, or sputtering.

[0047] S13, patterning the second dielectric layer 13 to form a plurality of first defining portions 14, wherein the first defining portions 14 are hollow structures, and the sidewall of one first defining portion 14 only fits with the sidewall of one first slot B (e.g., Figure 4b ).

[0048] The second dielectric layer 13 can be patterned through a patterning process to form a plurality of first defining portions 14. The sidewall thickness of the first defining portions 14 corresponds to the width of the conductive grid lines to be formed. The sidewall thickness of the first defining portions 14 can be selected based on the application. Preferably, the sidewall thickness of the first defining portions 14 is no greater than 1.5 μm.

[0049] S14, removing the first dielectric layer 12 having a plurality of first grooves formed thereon (eg, Figure 4c ).

[0050] S15 , forming a third dielectric layer 15 on a side of the second dielectric layer 12 having the plurality of first defining portions 14 facing away from the base substrate 11 , and processing the third dielectric layer 15 to expose a surface of the first defining portions 14 facing away from the base substrate 11 .

[0051] Specifically, the first dielectric layer 12 having multiple first grooves formed therein can be removed through an etching process, and a third dielectric layer 15 can be formed on the side of the second dielectric layer 12 having multiple first limiting portions 14 formed therein that faces away from the base substrate 11 through a coating process. The third dielectric layer 15 can then be processed through an etching process to expose the surface of the first limiting portions 14 that faces away from the base substrate 11.

[0052] The material of the third dielectric layer 15 may include but is not limited to positive photoresist, negative photoresist, PI (polyimide) glue, optically transparent glue, etc.

[0053] S16 , removing the first defining portion 14 to form a plurality of second grooves 16 in the third dielectric layer 15 .

[0054] Specifically, the first defining portion 14 may be removed by an etching process to form a plurality of second grooves 16 in the third dielectric layer 15 .

[0055] S17, forming a conductive material in the second slot 16 by electroplating process, and forming a pattern 17 (such as a conductive grid) by patterning process. Figure 4d ).

[0056] Specifically, first, the side of the base substrate 11 with the third dielectric layer 15 is placed on the electroplating machine carrier, a power pad is pressed on, and the substrate is placed in a hole-filling electroplating tank (a dedicated hole-filling electrolyte is used in the tank). Current is applied, and the electroplating solution is kept flowing rapidly on the surface of the base substrate 11. The cations in the electroplating solution on the sidewalls of the second groove 16 obtain electrons and become atoms and are deposited on the sidewalls. The conductive material on the sidewalls of the second groove 16 gradually grows thicker until the second groove 16 is completely filled. Finally, the base substrate 11 is removed and rinsed with deionized water. The conductive material includes but is not limited to copper (Cu), aluminum (Al), molybdenum (Mo), silver (Ag), etc. Then, the conductive material outside the second groove 16 can be removed by an etching process to form a pattern including a conductive grid.

[0057] In this embodiment, a third dielectric layer 15 is formed on a side of the second dielectric layer 13 having a plurality of first defining portions 14 formed thereon, facing away from the base substrate 11. The third dielectric layer 15 is processed to expose a surface of the first defining portions 14 facing away from the base substrate 11. The first defining portions 14 are then removed to form a plurality of second slots 16 in the third dielectric layer 15. A conductive material is then formed in the second slots 16. The line width of the conductive grid formed at this time is relatively narrow. Applying this conductive grid to a thin-film sensor can help improve the light transmittance of the product.

[0058] The present disclosure is described below with reference to several preferred embodiments:

[0059] Example 1:

[0060] Figure 5 A flow chart of another method for preparing a conductive grid provided in an embodiment of the present disclosure, such as Figure 5 As shown, the method for preparing the conductive grid includes:

[0061] S101: Provide a base substrate 41. Deposit a metal film layer 42 on the base substrate 41 as a seed layer. Form a first photoresist layer 43 on the side of the seed layer 42 facing away from the base substrate 11. Pattern the first photoresist layer 43 to form a plurality of first grooves. In this embodiment, the metal film layer 42 may be a copper film layer. Of course, it may also be a metal film layer made of other materials, which is not specifically limited here.

[0062] The thickness of the first photoresist layer 43 is the thickness of the conductive grid lines to be formed, and the width of the first photoresist layer 43 is the line spacing of the conductive grid lines to be formed.

[0063] S102, a second dielectric layer 44 is formed on the side of the first photoresist layer 43 with the plurality of first grooves away from the substrate 11, and the material of the second dielectric layer 44 is a silicon nitride SiNx layer.

[0064] Specifically, the silicon nitride SiNx layer 44 can be deposited by low-temperature chemical vapor deposition (CVD), and the thickness of the SiNx film layer 44 is designed according to the width of the conductive wire required by the conductive grid, and is generally deposited to 0.5-1.5 um.

[0065] S103, the silicon nitride SiNx layer 44 is patterned to form a plurality of first limiting portions 45, and the first limiting portion 45 is a hollow structure, and the sidewall of one first limiting portion 45 is only fitted with the sidewall of one first groove.

[0066] Specifically, the silicon nitride SiNx layer 44 can be patterned by a dry etching process.

[0067] S104, the first photoresist layer 43 with the plurality of first grooves is removed, and a second photoresist layer 46 is formed on the side of the silicon nitride SiNx layer with the plurality of first limiting portions 45 away from the substrate 11 by a coating process, and the second photoresist layer 46 is treated by plasma ashing to expose the surface of the first limiting portion 14 away from the substrate 11.

[0068] S105, the first limiting portion 45 is removed to form a plurality of second grooves 47 in the second photoresist layer 46.

[0069] Specifically, the first limiting portion 45 can be removed by a wet etching process to form a plurality of second grooves 47 in the second photoresist layer 46. For example, the width of the second groove 47 is not greater than 1.5 um, and the height is 1 um-3 um.

[0070] S106, a copper material is formed in the second groove 47 by an electroplating process. Then the second photoresist layer 46 is removed, and then the seed layer 42 is removed by an etching process, and then a pattern 48 including a conductive grid is formed.

[0071] Specifically, the side of the substrate 41 with the second photoresist layer 46 is placed on the electroplating machine carrier, a power pad is pressed on, and the substrate is placed in a hole-filling electroplating tank (a dedicated hole-filling electrolyte is used in the tank). Current is applied, and the electroplating solution is kept flowing rapidly on the surface of the substrate. The cations in the electroplating solution gain electrons on the sidewalls of the second groove 47, becoming atoms and depositing on the sidewalls. Through the specially formulated dedicated hole-filling electrolyte, it is possible to achieve high-speed copper deposition (deposition rate of 0.5-3um / min) mainly in the second groove 47. Over time, from pre-plating to formal electroplating, the copper on the sidewalls of the second groove 47 gradually grows thicker, and can even completely fill the second groove 47. Finally, the substrate 41 is removed and rinsed with deionized water. The current density for pre-plating is 0.1-0.5ASD, and the current density for formal electroplating is 1-2ASD. The second photoresist layer 46 is then removed, and the seed layer 42 is removed by an etching process, thereby forming a pattern 48 including a conductive grid.

[0072] S107 , planarizing the conductive grid 48 using transparent optical adhesive (OC adhesive) 49 .

[0073] In some embodiments, after step S48, the method further includes:

[0074] S108 , forming a passivation layer 491 on a side of the conductive grid 48 facing away from the substrate 41 .

[0075] In this embodiment, a passivation layer 491 is formed on the side of the conductive grid 48 facing away from the base substrate 41 to protect the conductive grid 48 and prevent the conductive grid 48 from being corroded by water and oxygen.

[0076] In this embodiment, a second photoresist layer 46 is formed on the side of the silicon nitride SiNx layer with multiple first defining portions 45 facing away from the substrate 41, and the second photoresist layer 46 is processed to expose the surface of the first defining portions 45 facing away from the substrate 41; the first defining portions 45 are then removed to form multiple second grooves 47 located in the second photoresist layer 16; and a conductive material is then formed in the second grooves 47. At this time, the conductive grid formed not only has a narrow line width of the conductive line (line width less than 1um, and after control, the minimum can reach less than 0.5um), but also has a thickness of up to 5um. This conductive grid is applied to thin-film sensors to help improve the light transmittance of the product. In addition, the preparation method of the conductive grid provided by the present disclosure has higher control accuracy, does not require a high-precision photo process, does not require alignment, only requires a mask, has a high yield, and supports a low-temperature (130°C) process during the preparation process, which is friendly to flexible substrates.

[0077] Example 2:

[0078] Figure 6 A flow chart of another method for preparing a conductive grid provided in an embodiment of the present disclosure, such as Figure 6 As shown, the method for preparing the conductive grid includes:

[0079] S201: Provide a base substrate 51, form a first photoresist layer 52 on the base substrate 51 through a coating process, and pattern the first photoresist layer 52 to form a plurality of first grooves. The thickness of the first photoresist layer 52 is the thickness of the conductive grid lines to be formed, and the width of the first photoresist layer 52 is the line spacing of the conductive grid lines to be formed.

[0080] S202 , forming a second dielectric layer 53 on a side of the first photoresist layer 52 with a plurality of first grooves formed therein, which side faces away from the base substrate 51 , wherein the material of the second dielectric layer is a silicon nitride SiNx layer.

[0081] Specifically, the silicon nitride SiNx film layer 53 may be deposited by low-temperature chemical vapor deposition (CVD). The thickness of the SiNx film layer 53 is designed according to the width of the conductive lines required by the conductive grid, and is generally deposited to 0.5 to 1.5 μm.

[0082] S203 , patterning the silicon nitride SiNx layer 53 to form a plurality of first defining portions 54 , wherein the first defining portions 54 are hollow structures, and a sidewall of a first defining portion 54 only fits with a sidewall of a first groove.

[0083] Specifically, the silicon nitride SiNx layer 53 may be patterned by a dry etching process.

[0084] S204, removing the first photoresist layer 52 formed with a plurality of first grooves, and forming an OC glue layer 55 on the side of the silicon nitride SiNx layer 53 formed with a plurality of first limiting portions 54 away from the base substrate 51 through a coating process, and treating the OC glue layer 55 by plasma ashing to expose the surface of the first limiting portion away from the base substrate 51.

[0085] S205 , removing the first limiting portion 54 to form a plurality of second grooves 56 in the OC adhesive layer 55 .

[0086] Specifically, the first defining portion 54 can be removed by a wet etching process to form a plurality of second grooves 56 in the OC glue layer 55. For example, the width of the second grooves 56 is no greater than 1.5 μm and the height is 1 μm to 3 μm.

[0087] S206: A metal film layer 57 as a seed layer may be formed by evaporation or sputtering on the side of the OC adhesive layer 56 facing away from the base substrate 51. The metal film layer 57 may be a copper film layer, or a metal film layer made of other materials, which is not specifically limited here.

[0088] S207 , electroplating the seed layer 57 to form a conductive material in the second groove 56 .

[0089] Specifically, the side of the substrate 51 with the OC adhesive layer 55 is placed on the electroplating machine carrier, a power pad is pressed on, and the substrate is placed in a via-filling plating tank (using a dedicated via-filling electrolyte). Current is applied, and the plating solution is kept flowing rapidly on the surface of the substrate 51. The cations in the plating solution gain electrons on the sidewalls of the second slot 56, becoming atoms and depositing on the sidewalls. The specially formulated dedicated via-filling electrolyte allows for high-speed copper deposition (deposition rate of 0.5-3 μm / min) primarily in the second slot 56. Over time, from pre-plating to final plating, the copper on the sidewalls of the second slot 56 gradually grows thicker, even completely filling the second slot 56. Finally, the substrate 51 is removed and rinsed with deionized water. The current density for pre-plating is 0.1-0.5 ASD, and the current density for final plating is 1-2 ASD.

[0090] S208 , removing the conductive material outside the second groove by an etching process, thereby forming a pattern 58 including a conductive grid.

[0091] In some embodiments, after step S208, the method further includes forming a passivation layer on the side of the conductive grid facing away from the substrate. By forming the passivation layer on the side of the conductive grid facing away from the substrate, the conductive grid is protected from being corroded by water and oxygen.

[0092] In this embodiment, an OC adhesive layer 55 is formed on the side of the silicon nitride SiNx layer, on which a plurality of first defining portions 54 are formed, facing away from the substrate 51. The OC adhesive layer 55 is then processed to expose the surface of the first defining portions 54 facing away from the substrate 51. The first defining portions 54 are then removed to form a plurality of second slots 56 in the OC adhesive layer 55. A conductive material is then formed in the second slots 56. The resulting conductive mesh not only has narrow conductive lines (less than 1 μm, with the smallest possible width capable of being less than 0.5 μm after control), but also has a thickness of up to 5 μm. This conductive mesh can be applied to thin-film sensors, helping to improve the light transmittance of the product. Furthermore, the conductive mesh fabrication method provided by the present disclosure offers higher control accuracy, eliminates the need for high-precision photoprocessing and alignment, requires only a single mask, and has a high yield. Furthermore, the fabrication process supports low-temperature (130°C) processing, making it compatible with flexible substrates.

[0093] Example 3

[0094] Figure 7 A flow chart of another method for preparing a conductive grid provided in an embodiment of the present disclosure is shown in FIG. Figure 7 As shown, the method for preparing the conductive grid includes:

[0095] S301: Provide a base substrate 61, apply a photoresist layer 62 to the base substrate 61, and pattern the photoresist layer to form a plurality of first grooves. In this embodiment, the thickness of the photoresist layer 62 is the thickness of the conductive grid lines to be formed, and the width of the photoresist layer 62 is the line spacing of the conductive grid lines to be formed.

[0096] S302 , forming a metal layer 63 on the side of the photoresist layer 62 with the plurality of first grooves formed therein, which side faces away from the base substrate 61 . The metal layer 63 is made of aluminum Al and silver Ag.

[0097] Specifically, the metal layer 63 may be formed by evaporation or sputtering. The thickness of the metal layer 63 is designed according to the width of the conductive lines required by the conductive grid, and is generally deposited to be 0.5 to 1.5 μm.

[0098] S303 , patterning the metal layer 63 through an etching process to form a plurality of first defining portions 64 .

[0099] S304 , removing the photoresist layer to form a pattern including a conductive grid, that is, the defining portion 64 is the conductive line of the conductive grid.

[0100] In this embodiment, since aluminum (Al) and silver (Ag) are used as the metal layer 62, no electroplating process is required, and the entire process can be completed in just five simple steps. Furthermore, the conductive mesh formed using this preparation method not only has a narrow conductive line width (less than 1 μm, with the ability to achieve a minimum thickness of less than 0.5 μm after control), but also has a thickness of up to 5 μm. Application of this conductive mesh to thin-film sensors can help improve the product's light transmittance.

[0101] In a second aspect, an embodiment of the present disclosure provides a method for preparing a thin film sensor, which includes the above-mentioned method for preparing a conductive grid.

[0102] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A method for preparing a conductive grid, characterized in that: include: Providing a base substrate, forming a first dielectric layer on the base substrate, and patterning the first dielectric layer to form a plurality of first grooves; A second dielectric layer is formed on a side of the first dielectric layer having the plurality of first grooves formed therein, facing away from the base substrate, and the second dielectric layer is patterned to form a plurality of first defining portions, wherein the first defining portions are hollow structures, and a sidewall of one first defining portion is aligned with a sidewall of only one first groove, and a thickness of the sidewall of the first defining portion is equal to the width of the conductive grid line to be formed; removing the first dielectric layer having the plurality of first grooves formed thereon, forming a third dielectric layer on a side of the second dielectric layer having the plurality of first defining portions formed thereon facing away from the base substrate, and processing the third dielectric layer to expose a surface of the first defining portions facing away from the base substrate; removing the first defining portion to form a plurality of second grooves in the third dielectric layer; A conductive material is formed in the second groove by an electroplating process, and a pattern including a conductive grid is formed by a patterning process.

2. The method for preparing a conductive grid according to claim 1, wherein: The forming of the conductive material in the second groove by the electroplating process includes: forming a conductive film layer as a seed layer on a side of the second dielectric layer facing away from the substrate; The seed layer is electroplated to form a conductive material in the second groove.

3. The method for preparing a conductive grid according to claim 2, wherein: The material of the third dielectric layer includes photoresist, OC glue or PI glue.

4. The method for preparing a conductive grid according to claim 1, wherein: The forming of the conductive material in the second groove by the electroplating process includes: Before the step of forming the first dielectric layer on the base substrate, a conductive film layer is formed on the base substrate as a seed layer; After the step of removing the first defining portion to form a plurality of second grooves in the third dielectric layer, the seed layer is electroplated to form the conductive material in the second grooves.

5. The method for preparing a conductive grid according to claim 4, wherein: The material of the third dielectric layer includes positive photoresist, negative photoresist or PI glue.

6. The method for preparing a conductive grid according to any one of claims 1 to 5, characterized in that: The material of the second dielectric layer includes silicon nitride or silicon oxide.

7. The method for preparing a conductive grid according to any one of claims 1 to 5, characterized in that: After forming the conductive grid, the method further includes: A passivation layer is formed on a side of the conductive grid facing away from the substrate.

8. The method for preparing a conductive grid according to any one of claims 1 to 5, wherein: The thickness of the first dielectric layer is 2-5 μm.

9. The method for preparing a conductive grid according to any one of claims 1 to 5, wherein: The sidewall thickness of the first defining portion is no more than 1.5 μm.

10. A method for preparing a thin film sensor, comprising the method for preparing the conductive grid according to any one of claims 1 to 9.

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