Method for manufacturing a mold and method for manufacturing a suspended imaging structure

Abstract

The embodiment of the present application provides a manufacturing method of a mold and a manufacturing method of a suspended imaging structure. The manufacturing method of the mold comprises the following steps: providing a first substrate, forming a photoresist on one side of the first substrate; performing photoetching on the side of the photoresist away from the first substrate, so that a part of the photoresist is denatured to form denatured photoresist; removing the denatured photoresist to form a plurality of groove structures on the side of the photoresist away from the first substrate; filling metal in the groove structures and covering the side of the photoresist away from the first substrate with the metal to form the mold. The mold manufactured by the manufacturing method in the embodiment has a large aspect ratio and can be used to manufacture the suspended imaging structure, and can be appropriately adjusted as a part of the suspended imaging structure.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for manufacturing a mold and a method for manufacturing a suspended imaging structure. Background Technology

[0002] Suspended imaging structures can control light transmission, refocusing the divergent light emitted by the light source into the air, allowing the human eye to observe the corresponding image from above. In related technologies, the reflective layer structure used for light adjustment requires a large aspect ratio, while conventional MEMS (Micro-Electro-Mechanical Systems) processes have low aspect ratios. Furthermore, for light adjustment structures to transmit light, good transparency is required in certain areas, but conventional MEMS processes typically use opaque silicon substrates, resulting in poor light transmittance. Summary of the Invention

[0003] The purpose of this application is to provide a method for manufacturing a mold and a method for manufacturing a suspended imaging structure, thereby providing a method for manufacturing suspended imaging structures with a large aspect ratio. The specific technical solution is as follows:

[0004] An embodiment of the first aspect of this application provides a method for manufacturing a mold, the steps of which include:

[0005] A first substrate is provided, and photoresist is formed on one side of the first substrate;

[0006] Photolithography is performed on the side of the photoresist away from the first substrate to deform a portion of the photoresist, forming a deformed photoresist.

[0007] Remove the modified photoresist to form multiple trench structures on the side of the photoresist away from the first substrate;

[0008] Metal is filled into the trench structure, and the metal covers the photoresist on the side away from the first substrate to form a mold.

[0009] According to the manufacturing method in this application embodiment, before forming photoresist on one side of the first substrate, the first substrate can be cleaned and dried to remove surface impurities. Then, photoresist of the required thickness is spin-coated onto one side of the first substrate using a thick-film spin coater, removing thicker edges to smooth the photoresist surface. Next, an X-ray irradiation process is performed, irradiating one side of the photoresist to denature it. Following this, a development process is performed, using a developer to react with the denatured photoresist, retaining the undeformed photoresist, and then baking to obtain the photoresist pattern. Finally, a metal electroplating growth process is performed, electroplating and growing metal to fill the grooves in the photoresist and continuously growing, covering the side of the photoresist away from the first substrate to form a mold. The mold manufactured by the method in this embodiment has a large aspect ratio and can be used to create a suspended imaging structure, or, with appropriate adjustments, can be used as part of a suspended imaging structure.

[0010] In some embodiments of this application, X-ray exposure is used to perform photolithography on the side of the photoresist away from the first substrate.

[0011] In some embodiments of this application, before the step of forming photoresist on one side of the first substrate, the method further includes: forming a conductive metal thin film on the first substrate;

[0012] The modified photoresist extends to the conductive metal thin film.

[0013] In some embodiments of this application, prior to the step of filling the groove structure with metal, the method further includes:

[0014] Metal is deposited on the side of the first substrate closest to the photoresist, the metal located within the trench structure is retained, and the metal on the side of the photoresist away from the first substrate is removed.

[0015] In some embodiments of this application, the step after forming a conductive metal thin film on the first substrate further includes: forming an adhesion layer on the side of the conductive metal thin film away from the first substrate.

[0016] In some embodiments of this application, prior to the step of forming photoresist on one side of the first substrate, a sacrificial layer is further formed on the first substrate.

[0017] In some embodiments of this application, the step following X-ray exposure lithography of the photoresist on the side away from the first substrate using a mask further includes:

[0018] Remove the photomask and use a generalized exposure method to illuminate the side of the photoresist away from the first substrate.

[0019] In some embodiments of this application, ultraviolet light is used to perform photolithography on the side of the photoresist away from the first substrate.

[0020] The second aspect of this application provides a method for manufacturing a suspended imaging structure, which is to manufacture the structure using a mold manufactured by the mold manufacturing method in any embodiment of the first aspect. The manufacturing method includes:

[0021] The mold is peeled off from the first substrate, and the photoresist attached to the mold is removed;

[0022] A second substrate is provided, and a transparent material layer is formed on one side of the second substrate;

[0023] A transparent material layer is molded using a mold to form multiple filling grooves, and a reflective layer is filled into the filling grooves.

[0024] In some embodiments of this application, the step after filling the reflective layer in the filling groove further includes forming a protective layer on the side of the transparent material layer and the reflective layer away from the second substrate.

[0025] In some embodiments of this application, the step prior to forming a transparent material layer on one side of the second substrate further includes forming a metal layer on one side of the second substrate.

[0026] In some embodiments of this application, the steps prior to filling the reflective layer into the filling groove further include:

[0027] Metal is deposited on the side of the transparent material layer away from the second substrate, the metal located in the filling trench is retained, and the metal on the side of the transparent material layer away from the second substrate is removed.

[0028] In some embodiments of this application, the steps prior to filling the reflective layer into the filling groove further include:

[0029] Metal is formed on the side of the transparent material layer away from the second substrate by electroplating, while the metal located in the filling tank near the second substrate is retained, and the metal on the side of the transparent material layer away from the second substrate and the metal in contact with the transparent material layer in the filling tank are removed.

[0030] In some embodiments of this application, the step of filling the filling groove with a reflective layer specifically includes:

[0031] Metal is deposited on the side of the transparent material layer away from the second substrate, the metal in contact with the transparent material layer is retained, and the metal near the second substrate is removed from the filling trench;

[0032] Transparent material is filled into the filling groove by injection molding.

[0033] In some embodiments of this application, the steps prior to filling the reflective layer into the filling groove further include:

[0034] Multiple transparent material layers are fixed together by adhesive, and multiple filling slots correspond one-to-one.

[0035] In some embodiments of this application, the steps following filling the reflective layer into the filling groove further include:

[0036] The transparent material layer and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including a second substrate and a second structure not including a second substrate;

[0037] The second structure is flipped over and fixed to the side of the second substrate away from the transparent material layer, with the metal layers of the first structure and the metal layers of the second structure intersecting at 90°.

[0038] A protective layer is applied to the surface of the transparent material layer and the reflective layer.

[0039] The third aspect of this application provides a method for manufacturing a suspended imaging structure, which is to manufacture the structure using a mold manufactured by the mold manufacturing method in any embodiment of the first aspect. The manufacturing method includes:

[0040] The mold is peeled off from the first substrate, and the photoresist attached to the mold is removed;

[0041] A first transparent material is filled into one side of the mold located in the groove structure by injection molding;

[0042] Remove the mold, retaining the structure of the first transparent material, which has multiple recesses.

[0043] Metal is formed on the surface of the first transparent material on one side of the recess, metal is retained on the inner wall of the recess, and metal located at the bottom of the recess is removed;

[0044] A second transparent material is filled into the recess by injection molding.

[0045] The fourth aspect of this application provides a method for manufacturing a suspended imaging structure, including a mold manufactured by the method for manufacturing a suspended imaging mold according to any embodiment of the first aspect, the manufacturing method further including:

[0046] Peel the mold off the first substrate;

[0047] A second substrate is provided, and the mold and photoresist are fixed on the second substrate, wherein the photoresist is in contact with the second substrate;

[0048] Remove the mold from the side furthest from the second substrate.

[0049] The fifth aspect of this application provides a method for manufacturing a suspended imaging structure, including a mold manufactured by the method for manufacturing a suspended imaging mold according to any embodiment of the first aspect, the manufacturing method further including:

[0050] Peel the mold off the first substrate, fold the mold over, and fix the mold to the first substrate;

[0051] Remove the photoresist from the groove structure of the mold;

[0052] A transparent substrate is formed by filling a groove structure with a transparent material through injection molding, with the filler covering the side of the metal away from the first substrate.

[0053] Remove the first substrate and remove the metal on the side away from the transparent substrate.

[0054] An embodiment of the sixth aspect of this application provides a method for manufacturing a mold, the steps of which include:

[0055] A silicon substrate is provided, and multiple grooves are formed on one side of the silicon substrate by deep silicon etching;

[0056] Metal is deposited on one side of the silicon substrate located in the groove, the metal located at the bottom of the groove is retained, and the metal located on the silicon substrate not at the bottom of the groove is removed;

[0057] Metal is formed on one side of the groove on a silicon substrate by electroplating;

[0058] Remove the silicon substrate to form a mold. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0060] Figure 1 A schematic diagram of the imaging principle of a suspended imaging structure;

[0061] Figure 2a This is a schematic diagram of one type of suspended imaging structure;

[0062] Figure 2b This is a schematic diagram of another type of suspended imaging structure;

[0063] Figure 3 This is a cross-sectional view of the suspended imaging structure;

[0064] Figure 4 This is a process flow diagram of the mold manufacturing method in the first embodiment of this application;

[0065] Figure 5 This is a schematic diagram of the electroplating principle in an embodiment of this application;

[0066] Figure 6 This is a process flow diagram of the mold manufacturing method in the second embodiment of this application;

[0067] Figure 7 This is a process flow diagram of the mold manufacturing method in the third embodiment of this application;

[0068] Figure 8 This is a process flow diagram of the mold manufacturing method in the fourth embodiment of this application;

[0069] Figure 9 This is a process flow diagram of the mold manufacturing method in the fifth embodiment of this application;

[0070] Figure 10 This is a process flow diagram of the mold manufacturing method in the sixth embodiment of this application;

[0071] Figure 11 This is a process flow diagram of mold peeling in the manufacturing method of the suspended imaging structure in the embodiments of this application;

[0072] Figure 12 This is a schematic diagram of the mold structure in an embodiment of this application;

[0073] Figure 13 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the first embodiment of this application;

[0074] Figure 14 This is a schematic diagram of the suspended imaging structure in an embodiment of this application;

[0075] Figure 15 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the second embodiment of this application;

[0076] Figure 16 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the third embodiment of this application;

[0077] Figure 17 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the fourth embodiment of this application;

[0078] Figure 18 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the fifth embodiment of this application;

[0079] Figure 19 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the sixth embodiment of this application;

[0080] Figure 20 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the seventh embodiment of this application;

[0081] Figure 21This is a process flow diagram of the manufacturing method of the suspended imaging structure in the eighth embodiment of this application;

[0082] Figure 22 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the ninth embodiment of this application;

[0083] Figure 23 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the tenth embodiment of this application;

[0084] Figure 24 This is a process flow diagram of the mold manufacturing method in the embodiments of this application (for silicon substrate manufacturing);

[0085] Figure 25 This is a process flow diagram of the manufacturing method of the suspended imaging structure in the embodiments of this application (using a silicon substrate);

[0086] Figure 26a This is a schematic diagram of the electroplating principle in the embodiments of this application (without connecting lines);

[0087] Figure 26b This is a schematic diagram of the electroplating principle in the embodiments of this application (connecting lines are shown on both sides);

[0088] Figure 26c This is a schematic diagram of the electroplating principle in the embodiments of this application (with connecting lines on one side);

[0089] Figure 26d This is a schematic diagram of the electroplating principle in the embodiments of this application (cutting the connecting lines). Detailed Implementation

[0090] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0091] like Figure 1 As shown, the suspended imaging structure can control the transmission of light, refocusing the divergent light emitted by the light source into the air, allowing the human eye to observe the corresponding image from above. Figure 2a and 2b The image shown is a top view of the suspended imaging structure. It can use either a strip pattern A or a grid pattern B; the strip pattern requires two strip structures intersecting at 90°. The pattern includes a transparent filler layer, an optical reflective layer, and a transparent substrate. Figure 3The diagram shown is a cross-sectional schematic of suspended imaging. Suspended imaging includes a transparent substrate 910, an optical reflective layer 920, and a transparent filling layer 930. The transparent filling layer 930 is used to support the structure and provide light transmission, the optical reflective layer 920 is used to reflect light, and the transparent substrate 910 provides light transmission.

[0092] In related technologies, the reflective layer structure used for light adjustment requires a large aspect ratio, while the geometric aspect ratio of the conventional MEMS process is low. Furthermore, in order to transmit light, the light adjustment structure needs to have good transparency in some areas, while the substrate commonly used in the conventional MEMS process is opaque silicon.

[0093] Based on this, such as Figure 4 As shown, an embodiment of the first aspect of this application discloses a method for manufacturing a mold, the steps of which include:

[0094] A first substrate 100 is provided, and a photoresist 200 is formed on one side of the first substrate 100; photolithography is performed on the side of the photoresist 200 away from the first substrate 100 to deform a portion of the photoresist 200, forming a deformed photoresist 210.

[0095] Remove the modified photoresist 210 to form a plurality of trench structures 220 on the side of the photoresist 200 away from the first substrate 100;

[0096] Metal 400 is filled into the trench structure 220, and the metal 400 covers the side of the photoresist 200 away from the first substrate 100 to form a mold.

[0097] According to the manufacturing method in this application embodiment, before forming photoresist 200 on one side of the first substrate 100, the first substrate 100 can be cleaned and dried to remove surface impurities. Then, photoresist 200 of the required thickness for the structure is spin-coated onto one side of the first substrate 100. The required thickness of photoresist 200 is spin-coated onto the substrate surface using a thick-film spin coater, and the thicker parts at the edges are removed to smooth the photoresist 200 surface. Next, an X-ray irradiation process S10 can be performed, in which one side of the photoresist 200 is irradiated with light to denature the photoresist 200. Then, a development process S20 is performed, in which the denatured photoresist 210 is reacted with a developer to remove the denatured photoresist 210, leaving the undeformed photoresist 200, and then post-baking is performed to obtain the photoresist 200 pattern. Finally, a metal electroplating growth process S30 can be implemented to electroplat and grow metal 400 into the trench structure 220 of the photoresist 200, and continue to grow, covering the side of the photoresist 200 away from the first substrate 100 to form a mold. The mold manufactured by the method in this embodiment has a large aspect ratio, which refers to the ratio of the depth to the width of an object; here, it refers to the ratio between the width and depth of the trench structure 220 formed after removing the modified photoresist 210. The mold in this embodiment includes two parts: a metal part and a photoresist part. The mold formed after removing the photoresist 200 can be called a metal mold, which can be used to fabricate a suspended imaging structure. Of course, the mold can simultaneously include a metal part and a photoresist part, thus, with appropriate processing, it can be used as part of a suspended imaging structure.

[0098] In some embodiments of this application, X-ray 10 exposure can be used to perform photolithography on the side of the photoresist 200 away from the first substrate 100. In this embodiment, X-ray 10 exposure can also be called synchrotron radiation exposure, which refers to a photolithography method that uses X-rays 10 as a light source for exposure. Its advantage is that the light source has good penetration ability and can expose photoresist 200 that is hundreds of micrometers thick.

[0099] In some embodiments of this application, prior to the step of forming photoresist 200 on one side of the first substrate 100, a thin film metal layer 300 is formed on the first substrate 100; the modified photoresist 210 extends to the thin film metal layer 300. In this embodiment, by forming the thin film metal layer 300 on one side of the first substrate 100, it can serve as a metal seed layer 310, after which metal 400 can be filled into the trench structure 220 by electroplating.

[0100] like Figure 5The diagram illustrates an electroplating process. The principle of electroplating is based on a redox reaction. The metal at the anode loses electrons, becoming metal ions that enter the electroplating solution 30. These metal ions gain electrons at the cathode and are deposited on it. For example, in this embodiment, the first substrate 100 and photoresist 200 located on one side of the first substrate 100 can be placed in the electroplating solution 30, with the thin-film metal layer 300 connected to the cathode. When the surface of the metal 400 at the cathode has a photoresist 200 pattern, the metal 400 can only be deposited into the gaps between the photoresist 200, that is, only into the trench structure 220, thus forming a metal 400 microstructure corresponding to the photoresist 200. Adding a surface tension agent to the electroplating solution, using pulsed power, or employing ultrasound to increase the convection of metal 400 ions and adjust the mold stress can overcome the surface tension of the electroplating solution 30, allowing them to enter the micropores.

[0101] like Figure 6 As shown, in some embodiments of this application, before the step of filling the trench structure 220 with metal 400, the metal 400 is deposited on the side of the first substrate 100 near the photoresist 200, retaining the metal 400 located in the trench structure 220, and removing the metal 400 on the side of the photoresist 200 away from the first substrate 100. In this embodiment, after the photoresist 200 is developed, a metal deposition process S40 can be performed to deposit metal 400 on the side of the photoresist 200 away from the first substrate 100. At this time, a surface etching process S41 can be performed to remove the metal 400 located on the surface of the photoresist 200, retaining the metal 400 located in the trench structure 220. In this way, the metal 400 in the trench structure 220 can be used for subsequent metal 400 electroplating in the metal seed layer 310.

[0102] like Figure 7As shown, in some embodiments of this application, the step after forming the thin film metal layer 300 on the first substrate 100 further includes forming an adhesion layer 500 on the side of the thin film metal layer 300 away from the first substrate 100. In this embodiment, when electroplating to form the metal 400, due to the high aspect ratio of the metal 400, the electroplating time in the electroplating solution 30 is long, and the electroplating solution 30 affects the adhesion between the photoresist 200 and the first substrate 100 or the metal 400. Therefore, in this embodiment, by forming the adhesion layer 500 on the side of the thin film metal layer 300 away from the first substrate 100, the photoresist 200 can be tightly bonded to the first substrate 100. For example, when the material of the thin film metal layer 300 is titanium, a layer of titanium oxide can be generated on the surface of titanium by chemical treatment. Titanium oxide is a porous material, which increases the contact area and increases the adhesion, or the adhesion performance can be improved by using an adhesion promoter. In some embodiments, the adhesion layer 500 may be disposed between the photoresist 200 and the thin film metal layer 300, or the adhesion layer 500 may be disposed between the first substrate 100 and the photoresist 200. Of course, the adhesion layer 500 may also be disposed between other layers where increased adhesion is required.

[0103] like Figure 8 As shown, in some embodiments of this application, before the step of forming photoresist 200 on one side of the first substrate 100, a sacrificial layer 600 is further formed on the first substrate 100. In this embodiment, a sacrificial layer 600 can be deposited, evaporated, or sputtered between the thin film metal layer 300 and the first substrate 100. The sacrificial layer 600 is made of a material that is relatively easy to remove, such as polyimide, silicon nitride, or polycrystalline silicon. It can also be a metal 400 that is easily removed, such as aluminum or molybdenum. The sacrificial layer 600 and the metal 400 have different etching conditions to achieve the separation of the upper structure from the substrate. In some specific embodiments, the first substrate 100 can be cleaned and dried at a certain temperature to remove water molecules from the surface of the first substrate 100. Then, a sacrificial layer 600 can be deposited, evaporated, or sputtered. When separating the first substrate 100 from the metal 400, the sacrificial layer 600 can be removed through a process S60 to separate the sacrificial layer. Next, the metal seed layer etching process S70 is performed, and finally the photoresist removal process S80 is performed.

[0104] like Figure 9As shown, in some embodiments of this application, after X-ray 10 exposure lithography of the side of photoresist 200 away from the first substrate 100 using mask 20, the steps further include: removing mask 20 and irradiating the side of photoresist 200 away from the first substrate 100 using a general exposure method. In this embodiment, negative photoresist 200 can be formed using X-ray 10 exposure with mask 20 and general exposure without mask 20, that is, a mask removal general exposure process S11 can be performed. Then, metal 400 is deposited on the side of photoresist 200 away from the first substrate 100, retaining the metal 400 located in the trench structure 220. The metal 400 located on the surface of photoresist 200 is removed by etching the metal 400. Finally, metal 400 is electroplated and grown in the trench structure 220.

[0105] like Figure 10 As shown, in some embodiments of this application, ultraviolet light 11 is used to perform photolithography on the side of the photoresist 200 away from the first substrate 100. In this embodiment, ultraviolet light 11 can also be used to perform photolithography on the side of the photoresist 200 away from the first substrate 100. Compared with synchrotron radiation lithography, ultraviolet light 11 lithography can reduce costs and processing cycles, and is currently the most promising metal 400 MEMS processing technology.

[0106] like Figures 11 to 13 As shown, an embodiment of the second aspect of this application proposes a method for manufacturing a suspended imaging structure, which is manufactured using a mold manufactured by the mold manufacturing method in any embodiment of the first aspect. The manufacturing method includes:

[0107] Peel the mold off the first substrate 100 and remove the photoresist 200 attached to the mold;

[0108] A second substrate 110 is provided, and a transparent material layer 700 is formed on one side of the second substrate 110;

[0109] A transparent material layer 700 is molded using a mold to form multiple filling grooves, and a reflective layer is filled into the filling grooves.

[0110] In this embodiment, a mold manufactured using the manufacturing method in any of the embodiments of the first aspect is used to manufacture a suspended imaging pattern. Therefore, a substrate removal process S50 can be performed first to peel the structure formed according to the first aspect embodiment from the first substrate 100. This can be done by directly peeling the structure from the first substrate 100, or by etching or polishing the first substrate 100. Next, the structure is inverted, and a thin film metal layer 300 etching process S51 is performed to etch away the thin film metal layer 300. Finally, a photoresist removal process S52 is performed to remove the photoresist 200 using a photoresist 200 solution or a plasma stripper, thus obtaining the metal mold. The metal mold formed according to this embodiment is the metal 400 portion of the mold in the first part of the embodiment, and its structure can be... Figure 12 Any one of the following. Next, a second substrate 110 is provided, and a transparent material layer 700 is formed on the second substrate 110. Then, a molding process S90 is performed, in which the transparent material layer 700 is molded using the metal mold to form a filling groove. Since the technical cost of X-ray 10 exposure is high, a single metal mold can be used to mold the transparent material layer 700 multiple times to form multiple filling grooves. Finally, metal 400 is filled into the filling groove to generate an optical reflective layer 920. The material of the reflective layer 920 filled with metal 400 can be the same as or different from the metal mold, provided that the reflectivity of the optical reflective layer 920 is satisfied. Figure 14 This is a schematic diagram of the formed suspended imaging structure, in which the second substrate 110 forms a transparent substrate 910, the metal 400 forms an optical reflective layer 920, and the photoresist 200 forms a transparent filler layer 930. This embodiment provides a method for fabricating a suspended display module including a transparent substrate 910, a transparent filler layer 930, and a high aspect ratio optical reflective layer 920. The method includes steps such as photolithography and electroplating, which can generate a structure with a high aspect ratio. Simultaneously, the transparent filler layer 930 can provide good support for the growth of the metal mold or the optical reflective layer 920.

[0111] The materials used for the second substrate 110 and the transparent material can include, but are not limited to, glass, PDMS (Polydimethylsiloxane), PMMA (polymethyl methacrylate), PC (polycarbonate), and PET (polyethylene glycol terephthalate). Compared to the prior art using MEMS technology, which uses opaque silicon as a substrate, this embodiment uses glass, PDMS, PMMA, PC, PET, and polyethylene terephthalate, which significantly increases the light transmittance of the second substrate. The optical reflective layer 920 includes, but is not limited to, highly reflective metals such as aluminum and silver, as well as polymer coatings.

[0112] like Figure 14 As shown, in some embodiments of this application, the step after filling the reflective layer in the filling groove further includes forming a protective layer 940 on the side of the transparent material layer 700 and the reflective layer away from the second substrate 110. In this embodiment, a protective layer 940 can be generated on the suspended imaging structure formed in the previous embodiment by bonding, adhesive, solidification, or other methods. The protective layer 940 can be smoothed by processes such as polishing. In this embodiment, the protective layer 940 is also required to be a transparent material with good light transmittance.

[0113] In this embodiment, the step prior to forming the transparent material layer 700 on one side of the second substrate 110 further includes forming a metal layer on one side of the second substrate 110. In this embodiment, the metal layer formed on one side of the second substrate 110 can serve as a metal seed layer 310, so that the metal 400 can be filled into the filler tank in a subsequent electroplating process.

[0114] like Figure 15 As shown, in some embodiments of this application, the steps before filling the reflective layer in the filling tank further include depositing metal 400 on the side of the transparent material layer 700 away from the second substrate 110, retaining the metal 400 located in the filling tank, and removing the metal 400 on the side of the transparent material layer 700 away from the second substrate 110. In this embodiment, a metal layer can be formed on the side of the transparent material layer 700 away from the second substrate 110 by processes such as deposition or sputtering, retaining the metal 400 located in the filling tank, and removing the metal 400 on the side of the transparent material layer 700 away from the second substrate 110. At this time, the metal 400 located on the surface of the transparent material layer 700 can be removed by etching. In this way, the metal 400 located in the filling tank can be used as a metal seed layer 310 so that the metal 400 can be filled into the filling tank in the subsequent electroplating process.

[0115] like Figure 16 As shown, in some embodiments of this application, the steps before filling the reflective layer in the filling tank further include: forming metal 400 on the side of the transparent material layer 700 away from the second substrate 110 by electroplating, retaining the metal 400 located in the filling tank near the second substrate 110, and removing the metal 400 on the side of the transparent material layer 700 away from the second substrate 110 and the metal 400 in contact with the transparent material layer 700 in the filling tank. In this embodiment, a metal layer growth process S42 can be performed first, forming metal 400 on the side of the transparent material layer 700 away from the second substrate 110 by electroplating, retaining the metal 400 located in the filling tank near the second substrate 110, and removing the metal 400 on the surface of the transparent material layer 700. At this time, the metal 400 on the surface of the transparent material layer 700 can be removed by etching. In this way, the metal 400 located in the filling tank near the second substrate 110 can be used as a metal seed layer 310 so that the metal 400 can be filled into the filling tank in the subsequent electroplating process.

[0116] like Figure 17 As shown, in some embodiments of this application, the step of filling the reflective layer in the filling groove specifically involves: depositing metal 400 on the side of the transparent material layer 700 away from the second substrate 110, retaining the metal 400 in contact with the transparent material layer 700, and removing the metal 400 near the second substrate 110 in the filling groove; and filling the filling groove with transparent material by injection molding. In this embodiment, the transparent material can be filled in the filling groove by injection molding process S91 to form the transparent material layer 700 of the suspended imaging structure.

[0117] like Figure 18 and Figure 19 As shown, in some embodiments of this application, the steps prior to filling the reflective layer in the filling groove further include:

[0118] Multiple transparent material layers 700 are fixed together by adhesive, and the multiple filling slots correspond one-to-one.

[0119] In this embodiment, the metal mold structure can be fabricated by deep silicon etching or UV light. However, the aspect ratio of these two methods is a maximum of 10. Therefore, when the transparent filling layer 930 is molded using this method, the height of the filling groove formed cannot meet the requirements. Therefore, an additional transparent filling layer 930 can be bonded and adhered to the transparent filling layer 930 to increase the overall height.

[0120] like Figure 20 As shown, in some embodiments of this application, the steps following filling the reflective layer into the filling groove further include:

[0121] The transparent material layer 700 and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including the second substrate 110 and a second structure not including the second substrate 110.

[0122] The second structure is flipped over and fixed on the side of the second substrate 110 away from the transparent material layer 700, wherein the metal layer 921 of the first structure and the metal layer 922 of the second structure intersect at 90°.

[0123] A protective layer 940 is applied to the surface of the transparent material layer 700 and the reflective layer.

[0124] In this embodiment, the suspended imaging structure can be cut along the direction in which the metal layer extends, such as... Figure 20 The cutting line M in the middle forms a suspended imaging structure with two parts. The first structure includes the second substrate 110, and the second structure does not include the second substrate 110. The second structure can be flipped and then fixed to one side of the second substrate 110. The metal layer 921 of the first structure and the metal layer 922 of the second structure intersect at 90°, thus forming an integral structure. In addition, a protective layer 940 can be covered on the surface of the transparent material layer 700 and the metal layer.

[0125] like Figure 21 As shown, an embodiment of the third aspect of this application proposes a method for manufacturing a suspended imaging structure, which is manufactured using a mold manufactured by the mold manufacturing method in any embodiment of the first aspect. The manufacturing method includes:

[0126] Peel the mold off the first substrate 100 and remove the photoresist 200 attached to the mold;

[0127] The mold is filled with a first transparent material 710 on one side of the groove structure 220 by injection molding;

[0128] Remove the mold while retaining the structure of the first transparent material 710, which has multiple recesses.

[0129] Metal 400 is formed on the surface of the first transparent material 710 on one side of the recess, metal 400 is retained on the inner wall of the recess, and metal 400 located at the bottom of the recess is removed.

[0130] The recess is filled with a second transparent material 720 by injection molding.

[0131] In this embodiment, a first transparent material 710 can be injection molded onto the mold manufactured in the first aspect to generate a first transparent material 710 structure corresponding to the mold. First, a process S53 involving metal deposition and surface etching after mold removal can be performed. That is, metal 400 is grown on the outer side of the first transparent material 710 structure, while retaining the metal 400 located on the inner wall of the recess and removing the metal 400 located at the bottom of the recess. Finally, a second transparent material 720 is injection molded. In this embodiment, the first transparent material 710 is the transparent substrate 910, the second transparent material 720 is the transparent filling layer 930, and the metal 400 is the optical reflective layer 920. In this embodiment, the first transparent material 710 and the second transparent material 720 can be the same material or different materials; there is no particular limitation. Furthermore, multiple of the above structures can be formed, and multiple structures can be bonded together by an adhesive process S92 to form a suspended imaging structure.

[0132] like Figure 22 As shown, an embodiment of the fourth aspect of this application proposes a method for manufacturing a suspended imaging structure, including a mold manufactured according to the manufacturing method of any embodiment of the first aspect, the manufacturing method comprising:

[0133] A first substrate 100 is provided, and a photoresist 200 is formed on one side of the first substrate 100;

[0134] X-ray 10 exposure lithography is performed on the side of photoresist 200 away from the first substrate 100 using mask 20, so that the photoresist 200 exposed to X-ray 10 is deformed.

[0135] Remove the modified photoresist 210 to form a plurality of trench structures 220 on the side of the photoresist 200 away from the first substrate 100;

[0136] Metal 400 is filled into the trench structure 220, and the metal 400 covers the side of the photoresist 200 away from the first substrate 100 to form a mold.

[0137] Peel the mold off the first substrate 100;

[0138] A second substrate 110 is provided, and a mold and photoresist 200 are fixed on the second substrate 110, wherein the photoresist 200 is in contact with the second substrate 110;

[0139] Remove the mold from the side furthest from the second substrate 110.

[0140] In this embodiment, the suspended imaging structure may include a mold manufactured according to the first aspect embodiment, wherein the mold includes a metal mold and a photoresist portion. After the metal 400 and photoresist 200 structure manufactured according to the first aspect embodiment is formed, a bonding process S81 can be performed first, that is, the metal 400 and photoresist 200 structure is flipped, wherein the portion having photoresist 200 is fixed to the second substrate 110 by bonding or adhesive. Then, an etching process S82 is performed to polish the metal 400 away from the second substrate 110, thereby obtaining the suspended imaging structure. Here, the metal 400 can be used as an optical reflective layer 920, the photoresist 200 as a transparent filler layer 930, and the second substrate 110 as a transparent substrate 910. At this time, the material of the second substrate 110 must be a transparent material.

[0141] like Figure 23 As shown, an embodiment of the fifth aspect of this application proposes a method for manufacturing a suspended imaging structure, including a mold manufactured according to the manufacturing method of any embodiment of the first aspect, the manufacturing method comprising:

[0142] Peel the mold off the first substrate 100, fold the mold over, and fix the mold to the first substrate 100;

[0143] Remove the photoresist 200 from the upper groove structure 220 of the mold;

[0144] A transparent substrate 910 is formed by filling the groove structure 220 with a transparent material through injection molding, and the filler covers the side of the metal 400 away from the first substrate 100.

[0145] Remove the first substrate 100 and remove the metal 400 on the side away from the transparent substrate 910.

[0146] In this embodiment, the suspended imaging structure may include a portion of the mold manufactured by the manufacturing method in the first aspect embodiment. For example, after obtaining the metal 400 and photoresist 200 structure in the first aspect embodiment, the structure can be folded over, at which point the photoresist 200 in the groove structure 220 of the mold can be removed. Then, a transparent material is filled into the groove structure 220, and subsequently, the first substrate 100 and the outermost metal 400 can be removed. In this embodiment, the metal 400 in the first aspect embodiment can serve as an optical reflective layer 920, and the transparent material is a transparent filler layer 930 and a transparent substrate 910. That is, both the transparent substrate 910 and the transparent filler layer 930 are transparent materials, and they are integrally formed.

[0147] like Figure 24 and Figure 25 As shown, an embodiment of the sixth aspect of this application discloses a method for manufacturing a mold, the steps of which include:

[0148] A silicon substrate 950 is provided, and multiple grooves are formed on one side of the silicon substrate 950 by deep silicon etching.

[0149] Metal 400 is deposited on one side of the silicon substrate 950 located in the groove, the metal 400 located at the bottom of the groove is retained, and the metal 400 located on the silicon substrate 950 not at the bottom of the groove is removed.

[0150] Metal 400 is formed on one side of the groove on the silicon substrate 950 by electroplating;

[0151] Remove the silicon substrate 950 to form a mold.

[0152] In this embodiment, the mold for suspended imaging can also be obtained by silicon-based etching. In this embodiment, since silicon material is relatively brittle, a deep silicon etching process S43 can be used. First, multiple grooves are formed on the silicon substrate 950. Metal 400 is deposited on one side of the silicon substrate 950 located in the grooves, retaining the metal 400 at the bottom of the grooves and removing the metal 400 located on the silicon substrate 950 not at the bottom of the grooves. Alternatively, metal 400 can be formed on one side of the silicon substrate 950 located in the grooves by electroplating. Finally, a silicon substrate removal process S44 is performed to remove the silicon substrate 950, thus forming the mold.

[0153] like Figure 26a , 26b As shown in 26c and 26d, in some embodiments of this application, metal 400 can be produced by electroplating. In the electroplating process, such as... Figure 26a The structure is such that multiple metal strips (400) are not connected together, but electroplating requires connecting multiple strips. Therefore, a method such as... Figure 26b and Figure 26c The structure shown connects multiple metal 400 wires together via connecting wire 311, as follows: Figure 26d As shown, after electroplating is completed, the part with connecting line 311 can be separated at dividing line 312.

[0154] The beneficial effects of this application are:

[0155] The embodiments of this application are based on the LIGA process, where LIGA is an abbreviation of the German words Lithographie, Galvanoformung, and Abformung, which are photolithography, electroforming, and injection molding, respectively. In other words, this embodiment uses a combination of photolithography, electroplating, and injection molding processes to fabricate devices with heights ranging from several hundred to several thousand micrometers, achieving high lateral dimensional accuracy and forming structures with aspect ratios of hundreds.

[0156] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0157] The various embodiments in this specification are described in a related manner. Similar or identical parts between the embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0158] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A method for manufacturing a suspended imaging structure, characterized in that, The manufacturing method includes: A first substrate is provided, and photoresist is formed on one side of the first substrate; Photolithography is performed on the side of the photoresist away from the first substrate to deform a portion of the photoresist, forming a deformed photoresist; Remove the modified photoresist to form a plurality of trench structures on the side of the photoresist away from the first substrate; Metal is filled into the trench structure, and the metal covers the side of the photoresist away from the first substrate to form a mold; Peel the mold off the first substrate and remove the photoresist attached to the mold; A second substrate is provided, and a transparent material layer is formed on one side of the second substrate; The transparent material layer is molded using the mold to form a plurality of filling grooves, and a reflective layer is filled in the filling grooves; The transparent material layer and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including a second substrate and a second structure not including a second substrate; The second structure is flipped over and fixed on the side of the second substrate away from the transparent material layer, with the metal layer of the first structure and the metal layer of the second structure intersecting at 90°; A protective layer is applied to the surfaces of the transparent material layer and the reflective layer.

2. The manufacturing method according to claim 1, characterized in that, The step after filling the reflective layer in the filling groove further includes forming a protective layer on the side of the transparent material layer and the reflective layer away from the second substrate.

3. The manufacturing method according to claim 1, characterized in that, The step prior to forming a transparent material layer on one side of the second substrate further includes forming a metal layer on one side of the second substrate.

4. The manufacturing method according to claim 1, characterized in that, The step prior to filling the reflective layer into the filling groove further includes: Metal is deposited on the side of the transparent material layer away from the second substrate, the metal located in the filling trench is retained, and the metal on the side of the transparent material layer away from the second substrate is removed.

5. The manufacturing method according to claim 1, characterized in that, The step prior to filling the reflective layer into the filling groove further includes: Metal is formed on the side of the transparent material layer away from the second substrate by electroplating, the metal located in the filling groove near the second substrate is retained, and the metal on the side of the transparent material layer away from the second substrate and the metal in the filling groove that is in contact with the transparent material layer are removed.

6. The manufacturing method according to claim 1, characterized in that, The step of filling the reflective layer in the filling groove is specifically as follows: Metal is deposited on the side of the transparent material layer away from the second substrate, the metal in contact with the transparent material layer is retained, and the metal near the second substrate of the filling trench is removed; Transparent material is filled into the filling groove by injection molding.

7. The manufacturing method according to claim 1, characterized in that, The step prior to filling the reflective layer into the filling groove further includes: Multiple transparent material layers are fixed together by adhesive, and the multiple filling slots correspond one-to-one.

8. The manufacturing method according to claim 1, characterized in that, Photolithography is performed on the side of the photoresist away from the first substrate to denature a portion of the photoresist, forming a denatured photoresist. This includes photolithography on the side of the photoresist away from the first substrate using X-ray exposure.

9. The manufacturing method according to claim 8, characterized in that, Before the step of forming photoresist on one side of the first substrate, the method further includes: forming a conductive metal thin film on the first substrate; The modified photoresist extends into the conductive metal film.

10. The manufacturing method according to claim 8, characterized in that, Prior to the step of filling the groove structure with metal, the method further includes: Metal is deposited on the side of the first substrate closest to the photoresist, the metal located within the trench structure is retained, and the metal on the side of the photoresist away from the first substrate is removed.

11. The manufacturing method according to claim 9, characterized in that, The step after forming a conductive metal thin film on the first substrate further includes forming an adhesion layer on the side of the conductive metal thin film away from the first substrate.

12. The manufacturing method according to claim 9, characterized in that, Before the step of forming photoresist on one side of the first substrate, the method further includes: forming a sacrificial layer on the first substrate.

13. The manufacturing method according to claim 8, characterized in that, The step following the X-ray exposure process of photolithography on the side of the photoresist away from the first substrate further includes: Remove the photomask and expose the photoresist away from the first substrate using a generalized exposure method.

14. The manufacturing method according to claim 1, characterized in that, Photolithography is performed on the side of the photoresist away from the first substrate using ultraviolet light.

15. A method for manufacturing a suspended imaging structure, characterized in that, The manufacturing method includes: A first substrate is provided, and photoresist is formed on one side of the first substrate; Photolithography is performed on the side of the photoresist away from the first substrate to deform a portion of the photoresist, forming a deformed photoresist; Remove the modified photoresist to form a plurality of trench structures on the side of the photoresist away from the first substrate; Metal is filled into the trench structure, and the metal covers the side of the photoresist away from the first substrate to form a mold; Peel the mold off the first substrate and remove the photoresist attached to the mold; A first transparent material is filled into one side of the mold located in the groove structure by injection molding; Remove the mold while retaining the structure of the first transparent material, which has multiple recesses. Metal is formed on the surface of the first transparent material on one side of the recess, metal is retained on the inner wall of the recess, and metal located at the bottom of the recess is removed; A second transparent material is filled into the recess by injection molding. In this configuration, the metal located on the sidewall of the recess is used as a reflective layer, the first transparent material is used as a second substrate, and the second transparent material is used as a transparent material layer. The method further includes: The transparent material layer and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including a second substrate and a second structure not including a second substrate; The second structure is flipped over and fixed on the side of the second substrate away from the transparent material layer, with the metal layer of the first structure and the metal layer of the second structure intersecting at 90°; A protective layer is applied to the surfaces of the transparent material layer and the reflective layer.

16. A method for manufacturing a suspended imaging structure, characterized in that, The manufacturing method further includes: A first substrate is provided, and photoresist is formed on one side of the first substrate; Photolithography is performed on the side of the photoresist away from the first substrate to deform a portion of the photoresist, forming a deformed photoresist; Remove the modified photoresist to form a plurality of trench structures on the side of the photoresist away from the first substrate; Metal is filled into the trench structure, and the metal covers the side of the photoresist away from the first substrate to form a mold; Peel the mold off the first substrate; A second substrate is provided, and a mold and photoresist are fixed on the second substrate, wherein the photoresist is in contact with the second substrate; Remove the metal from the side furthest from the second substrate; In this design, the metal is used as a reflective layer, and the photoresist is used as a transparent material layer. The method further includes: The transparent material layer and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including a second substrate and a second structure not including a second substrate; The second structure is flipped over and fixed on the side of the second substrate away from the transparent material layer, with the metal layer of the first structure and the metal layer of the second structure intersecting at 90°; A protective layer is applied to the surfaces of the transparent material layer and the reflective layer.

17. A method for manufacturing a suspended imaging structure, characterized in that, The manufacturing method further includes: A first substrate is provided, and photoresist is formed on one side of the first substrate; Photolithography is performed on the side of the photoresist away from the first substrate to deform a portion of the photoresist, forming a deformed photoresist; Remove the modified photoresist to form a plurality of trench structures on the side of the photoresist away from the first substrate; Metal is filled into the trench structure, and the metal covers the side of the photoresist away from the first substrate to form a mold; Peel the mold off the first substrate, fold the mold over, and fix the mold to the first substrate; Remove the photoresist from the groove structure on the mold; A transparent substrate is formed by filling the groove structure with a transparent material through injection molding, and the transparent material covers the side of the metal away from the first substrate. Remove the first substrate and remove the metal on the side away from the transparent substrate; In this configuration, the metal is used as a reflective layer, the transparent material within the groove structure is used as a transparent material layer, and the transparent substrate is used as a second substrate. The method further includes: The transparent material layer and the reflective layer are cut along a direction perpendicular to the extension of the reflective layer to form a first structure including a second substrate and a second structure not including a second substrate; The second structure is flipped over and fixed on the side of the second substrate away from the transparent material layer, with the metal layer of the first structure and the metal layer of the second structure intersecting at 90°; A protective layer is applied to the surfaces of the transparent material layer and the reflective layer.

Images