Diffraction waveguide module, preparation method thereof and display device

Abstract

The invention discloses a diffraction waveguide module, a preparation method thereof and a display device. The method for preparing the diffraction waveguide module comprises the steps that a first waveguide assembly is formed, the first waveguide assembly comprises a first substrate and a first grating layer located on the surface of one side of the first substrate, and the first grating layer covers part of the surface of the first substrate; providing a first cover plate, and performing hydrophilic treatment on the first cover plate and the first grating layer; enabling the surface, far away from the first substrate, of the first grating layer after hydrophilic treatment to be in direct contact with the surface of the first cover plate; and carrying out annealing treatment on the first cover plate and the first grating layer. Therefore, the contact surface of the first cover plate and the first grating layer can form strong bonding, so that the firm combination of the first cover plate and the first grating layer is realized; moreover, the grating in the module prepared by the method is not easy to damage, and the module has high reliability.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular, to a diffraction waveguide module and a method for preparing the same, and a display device. Background Art

[0002] In recent years, augmented reality has received widespread attention as the next generation computing platform. Current optical display technologies mainly include array waveguide solutions, volume holographic solutions, Birdbath (curved mirror with beam separation function, light from the vertical curved mirror is reflected onto the curved mirror through a beam splitter) solutions, free-form surface solutions, etc. The diffraction waveguide solution based on surface relief is regarded as one of the mainstream optical display solutions for AR complete products due to its small size, light weight, high transmittance, easy to be made into glasses and good wearing experience.

[0003] Diffraction waveguide technology is mainly divided into one-dimensional architecture and two-dimensional architecture. The one-dimensional architecture solution includes coupling-in, turning and coupling-out gratings, and the two-dimensional architecture solution only includes coupling-in and coupling-out gratings. The basic principle is that the coupling-in grating couples the light of the optical machine into the waveguide and propagates forward through total reflection inside the waveguide, and couples it out after pupil expansion through the turning grating or the coupling-out grating, so as to fuse the external ambient light with the virtual information and finally reach the human eye to enhance reality.

[0004] However, the reliability of the current diffraction waveguide module is poor, and the cover plate is easily deformed when subjected to external force, resulting in grating damage, which affects the performance of the diffraction waveguide module. Therefore, the current diffraction waveguide module and its preparation method, and display device still need to be improved. Summary of the invention

[0005] This application is based on the inventor's discovery and understanding of the following facts and problems:

[0006] In the related art, the waveguide assembly is bonded to the cover plate by means of frame pasting, see Figure 1 The waveguide component includes a substrate 1 and a grating 2 on the substrate 1. Only the edge area of ​​the waveguide component is bonded to the cover plate 4 through a bonding material 3, and there is a gap between the grating 2 and the cover plate 4. Figure 2When an external force acts on the cover plate 4, the waveguide component and the cover plate 4 are supported only by the adhesive material 3 in the edge area, and there are no more supporting points in the middle part. The cover plate 4 is easily deformed, resulting in damage to the grating 2, affecting the optical properties of the waveguide component, and further affecting the user experience. The inventor has found through a large number of experiments that the side surface of the waveguide component with the grating and the surface of the cover plate can be directly contacted and strongly bonded by melt bonding, so that the waveguide component and the cover plate are firmly combined. There are more supporting points between the waveguide component and the cover plate, which can improve the reliability of the waveguide component. When the cover plate is subjected to external force, the grating is not easily damaged; further, the cover plate can be thinned to achieve lightweight and miniaturization of the waveguide module.

[0007] In view of this, the present application aims to alleviate or solve at least one of the above-mentioned problems to at least some extent.

[0008] In one aspect of the present application, the present application proposes a method for preparing a diffraction waveguide module. In some embodiments of the present application, the method for preparing a diffraction waveguide module includes: forming a first waveguide component, the first waveguide component includes a first substrate and a first grating layer located on a side surface of the first substrate, the first grating layer covers a portion of the surface of the first substrate; providing a first cover plate, and performing a hydrophilic treatment on the first cover plate and the first grating layer; making the surface of the first grating layer after the hydrophilic treatment away from the first substrate directly contact the surface of the first cover plate; and performing an annealing treatment on the first cover plate and the first grating layer. As a result, the contact surface of the first cover plate and the first grating layer can form a strong bond, thereby achieving a firm combination of the first cover plate and the first grating layer; and the grating in the module prepared by this method is not easily damaged, and the module has a high reliability.

[0009] In some embodiments of the present application, the hydrophilic treatment includes plasma treatment, and / or the temperature of the annealing treatment is 400° C.-1000° C.; and / or the time of the annealing treatment is 0.5 h-3 h. This is conducive to further improving the overall performance of the diffractive waveguide module.

[0010] In some embodiments of the present application, forming the first waveguide component includes: providing a first substrate; depositing a first material layer on a side surface of the first substrate, wherein the refractive index of the first material layer is 2.0-3.0; etching the first material layer at least once to form a first grating layer. Thus, the first waveguide component formed can couple in and / or couple out light, thereby fusing the external environment light with the virtual information to reach the human eye, thereby playing the role of augmenting reality.

[0011] In some embodiments of the present application, after depositing the first material layer on one side surface of the first substrate, etching the first material layer once includes: forming a chromium film layer on the surface of the first material layer away from the first substrate; forming a photoresist layer on the surface of the chromium film layer away from the first substrate; exposing and developing the photoresist layer to form a patterned glue layer; etching the chromium film layer to form a patterned chromium layer, and removing the patterned glue layer; etching the first material layer to form at least one first grating; removing at least a portion of the patterned chromium layer. The above method can be used to etch the first material layer as needed to obtain a first grating layer with a desired shape and size.

[0012] In some embodiments of the present application, the method for preparing a diffractive waveguide module further includes: thinning the first cover plate. By thinning the first cover plate, the diffractive waveguide module can have a thinner thickness, which is conducive to lightweight and miniaturization of the diffractive waveguide module.

[0013] In some embodiments of the present application, the method for preparing a diffractive waveguide module satisfies at least one of the following conditions: the thinning process includes chemical mechanical polishing; the thickness of the first cover plate before the thinning process is 0.1mm-1mm; the thickness of the first cover plate after the thinning process is 0.05mm-0.3mm; the material of the first cover plate includes at least one of glass, resin and sapphire; the material of the first substrate includes glass; the thickness of the first substrate is 0.1mm-3mm; the material of the first material layer includes at least one of titanium dioxide, silicon nitride, hafnium dioxide, tantalum pentoxide and zirconium dioxide. Thus, it is beneficial to further improve the overall performance of the diffractive waveguide module.

[0014] In some embodiments of the present application, the method for preparing a diffractive waveguide module further includes the step of forming at least one second waveguide component, the second waveguide component is located on a side of the first waveguide component away from the first cover plate, the second waveguide component includes a second substrate and a second grating layer located on a surface of one side of the second substrate, the edge region of the second substrate of the second waveguide component closest to the first waveguide component is bonded to the first substrate of the first waveguide component through a first adhesive layer, and there is a gap between the second grating layer and the first substrate. Thus, the stacking of multiple waveguide components can achieve a better color display effect, which is conducive to improving the user experience.

[0015] In some embodiments of the present application, the method for preparing a diffractive waveguide module further includes: attaching a second cover plate to a side of the first substrate away from the first grating layer. Thus, the second cover plate can better protect the waveguide component, thereby further improving the reliability of the diffractive waveguide module.

[0016] In another aspect of the present application, the present application proposes a diffraction waveguide module. In some embodiments of the present application, the diffraction waveguide module is a diffraction waveguide module prepared by the method described above. Therefore, the diffraction waveguide module has high reliability, and the grating is not easily damaged when the cover plate is subjected to external force.

[0017] In another aspect of the present application, the present application provides a display device. In some embodiments of the present application, the display device includes the diffractive waveguide module described above. Therefore, the display device has all the features and advantages of the diffractive waveguide module described above, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 The schematic diagram of the structure of the diffraction waveguide module in the related art is shown;

[0020] Figure 2 A schematic diagram showing the deformation of a cover plate of a diffraction waveguide module in the related art due to an external force;

[0021] Figure 3 A flow chart of a method for preparing a diffractive waveguide module according to an embodiment of the present application is shown;

[0022] Figure 4 A flow chart of a method for preparing a diffractive waveguide module according to another embodiment of the present application is shown;

[0023] Figure 5 A partial flow chart of a method for preparing a diffractive waveguide module according to an embodiment of the present application is shown;

[0024] Figure 6 A partial flow chart of a method for preparing a diffractive waveguide module according to an embodiment of the present application is shown;

[0025] Figure 7 A flow chart of a method for preparing a diffractive waveguide module according to another embodiment of the present application is shown;

[0026] Figure 8 A flow chart of a method for preparing a diffraction waveguide module according to another embodiment of the present application is shown.

[0027] Description of reference numerals:

[0028] 100: first waveguide component; 110: first substrate; 120: first grating layer; 120': first material layer; 121-1: diamond-shaped first grating; 121-2: rectangular first grating; 200: first cover plate; 300: second cover plate; 400: second glue layer; 500: second waveguide component; 510: second substrate; 520: second grating layer; 600: first glue layer; 10': chrome film layer; 10: patterned chrome layer; 20': photoresist layer; 20: patterned glue layer; 1: substrate; 2: grating; 3: bonding material; 4: cover plate. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0030] As mentioned above, in the related art, there is a gap between the grating and the cover plate of the waveguide assembly, and the waveguide assembly is bonded to the cover plate only by adhesive material in the edge area. When the cover plate is subjected to external force, the cover plate is easily deformed, causing damage to the grating and affecting the performance of the waveguide assembly.

[0031] In order to at least alleviate or even solve the above technical problems to a certain extent, in one aspect of the present application, the present application proposes a method for preparing a diffractive waveguide module. In some embodiments of the present application, reference is made to Figures 3 to 8 The method for preparing a diffractive waveguide module may include the following steps:

[0032] S100: forming a first waveguide component.

[0033] In some embodiments of the present application, reference Figures 3 to 5 , forming a first waveguide component 100, wherein the first waveguide component 100 may include a first substrate 110 and a first grating layer 120 located on a side surface of the first substrate 110, and the first grating layer 120 covers a portion of the surface of the first substrate 110.

[0034] In some embodiments of the present application, reference Figure 5 , forming the first waveguide component may include the following steps:

[0035] S110: providing a first substrate.

[0036] In some embodiments of the present application, the material of the first substrate 110 may include glass. For example, the material of the first substrate 100 may be glass.

[0037] In some embodiments of the present application, the refractive index of the first substrate 110 may be greater than 2.0 or equal to 2.0.

[0038] In some embodiments of the present application, the first substrate 110 may be a high-refractive glass substrate having a refractive index greater than 2.0 or equal to 2.0.

[0039] In some embodiments of the present application, the thickness of the first substrate 110 may be 0.1 mm-3 mm. For example, the thickness of the first substrate 110 may be 0.1 mm, 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0040] In some embodiments of the present application, before forming other film layers on the first substrate 110 , the first substrate 110 may be cleaned to remove impurities such as dust and oil on the surface of the first substrate 110 .

[0041] S120: depositing a first material layer on a surface of one side of the first substrate.

[0042] refer to Figure 5 , a first material layer 120' is deposited on one side surface of the first substrate 110, wherein the refractive index of the first material layer 120' may be 2.0-3.0, for example, the refractive index of the first material layer 120' may be 2.0, 2.1, 2.3, 2.5, 2.8, 3.0, etc. Thus, the first material layer has a relatively high refractive index, and after the grating is formed by etching, the grating can couple in and / or couple out light, thereby fusing the external ambient light with the virtual information to reach the human eye, playing the role of augmenting reality.

[0043] In some embodiments of the present application, the material of the first material layer 120' may include at least one of titanium dioxide (TiO2), silicon nitride (Si3N4), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5) and zirconium dioxide (ZrO2). In some embodiments of the present application, the material of the first material layer 120' may be titanium dioxide, silicon nitride, hafnium dioxide, tantalum pentoxide or zirconium dioxide.

[0044] In some embodiments of the present application, the first material layer 120' may be deposited by at least one of PVD (physical vapor deposition), CVD (chemical vapor deposition), ALD (atomic layer deposition) and other methods. In some specific embodiments of the present application, the first material layer 120' may be deposited by PECVD (plasma enhanced chemical vapor deposition). Of course, those skilled in the art may also use other coating methods to form the first material layer 120' according to actual conditions.

[0045] S130: Etching the first material layer at least once to form a first grating layer.

[0046] In some embodiments of the present application, reference Figure 5 and Figure 6 After forming the first material layer 120 ′, the first material layer 120 ′ is etched at least once to form the first grating layer 120 .

[0047] In some embodiments of the present application, reference Figure 5 and Figure 6 After the first material layer 120' is deposited on one side surface of the first substrate 110, etching the first material layer 120' may include the following steps:

[0048] S131: forming a chromium film layer on a surface of the first material layer away from the first substrate.

[0049] refer to Figure 5 A chromium film layer 10 ′ is formed on a surface of the first material layer 120 ′ away from the first substrate 110 .

[0050] In some embodiments of the present application, a chromium film layer 10' may be deposited on the surface of the first material layer 120' away from the first substrate 110 by material PVD (physical vapor deposition) and / or thermal evaporation. The above method may form a chromium film layer with uniform thickness and smooth surface.

[0051] In some embodiments of the present application, the thickness of the chromium film layer 10' may be 10nm-200nm. For example, the thickness of the chromium film layer 10' may be 10nm, 20nm, 50nm, 80nm, 100nm, 130nm, 150nm, 200nm, etc. The thickness of the chromium film layer 10' is set within the above range. When the first material layer 120' is etched, the chromium film layer can be used as a mask to protect a partial area of ​​the first material layer, thereby forming a first grating layer with a desired shape and size by etching.

[0052] S132: forming a photoresist layer on the surface of the chromium film layer away from the first substrate.

[0053] In some embodiments of the present application, reference Figure 5 A photoresist layer 20' is formed on the surface of the chromium film layer 10' away from the first substrate 110. The photoresist layer 20' is made of photoresist (photoresist), and can be processed by exposure and development processes to form a patterned film structure.

[0054] In some embodiments of the present application, the photoresist layer 20 ′ may be formed by coating. For example, the photoresist layer 20 ′ may be formed on the surface of the chromium film layer 10 ′ away from the first substrate 110 by spin coating.

[0055] S133: exposing and developing the photoresist layer to form a patterned resist layer.

[0056] After forming the photoresist layer 20', refer to Figure 5 , the photoresist layer 20' is exposed and developed to form a patterned resist layer 20. In some embodiments of the present application, the photoresist layer 20' can be exposed by at least one of EBL (electron beam exposure), holographic laser interference, DUV (deep ultraviolet light), EUV (extreme ultraviolet light), etc.

[0057] After the exposure process, the photoresist layer is developed to remove a portion of the photoresist layer, thereby forming a patterned resist layer 20 .

[0058] S134: etching the chromium film layer to form a patterned chromium layer, and removing the patterned glue layer.

[0059] refer to Figure 5 After forming the patterned glue layer 20, the chromium film layer 10' is etched to form the patterned chromium layer 10. In some embodiments of the present application, the chromium film layer 10' can be etched by plasma dry etching to form an opening to obtain the patterned chromium layer 10.

[0060] refer to Figure 5 In some embodiments of the present application, after forming the patterned chromium layer 10 , the patterned glue layer 20 may be etched using O 2 plasma to remove the patterned glue layer 20 .

[0061] S135: Etching the first material layer to form at least one first grating.

[0062] Using the patterned chromium layer 10 as a mask, the first material layer 120' is etched to form at least one first grating. Figure 6 , using the patterned chromium layer 10 as a mask, the first material layer 120 ′ is etched to form a first grating layer 120 , and the first grating layer may have a plurality of first gratings.

[0063] S136: removing at least a portion of the patterned chromium layer.

[0064] In some embodiments of the present application, the first material layer 120' is etched to remove at least a portion of the patterned chromium layer 10. Figure 6 , the first material layer 120 ′ is etched, and the patterned chromium layer 10 is removed.

[0065] In some embodiments of the present application, the first material layer 120' may be etched by RIBE (reactive ion beam etching) and / or ICP etching (inductively coupled plasma etching) processes. In some specific embodiments of the present application, the first material layer 120' may be made of titanium dioxide, and the titanium dioxide film layer may be etched by RIBE and / or ICP etching processes.

[0066] In some embodiments of the present application, wet etching may be used to remove the patterned chromium layer 10 .

[0067] In some embodiments of the present application, reference Figure 5 and Figure 6 When the first gratings in the first grating layer are of the same shape, such as a rhombus, the first grating layer can be formed by etching once. Figure 4 The first grating layer 120 includes two shapes of first gratings and a non-grating part. Specifically, the first grating layer 120 may include two rhombus first gratings 121-1 and two rectangular first gratings 121-2. The other rectangular areas in the first grating layer 120 are non-grating parts. The rhombus first grating 121-1 in the first grating layer can be formed by one step of etching, and the rectangular first grating 121-2 and the non-grating part can be formed by another step of etching. When multiple etchings are required to obtain the first grating layer, steps S132 to S136 can be repeated. It should be noted that Figure 4 The number of gratings in the present application is not intended to limit the present application, and the number of first gratings in the present application can be more.

[0068] In some embodiments of the present application, after the etching process of the first material layer is completed, the etched component may be cleaned to obtain a clean first waveguide component.

[0069] S200: performing hydrophilic treatment on the first cover plate and the first grating layer.

[0070] In some embodiments of the present application, reference Figure 3 , Figure 4 and Figure 6 , provide a first cover plate 200, perform hydrophilic treatment on the surface of the first cover plate 200 and the surface of the first grating layer 120, and introduce a large number of hydrophilic groups (such as -OH, etc.) on the surface of the first cover plate 200 and the surface of the first grating layer 120.

[0071] In some embodiments of the present application, the hydrophilic treatment may include plasma treatment. By performing plasma treatment on the surface of the first cover plate 200 and the surface of the first grating layer 120, a large number of hydrophilic groups can be introduced onto the surface of the first cover plate 200 and the surface of the first grating layer 120, which is beneficial to the subsequent firm bonding of the first cover plate and the first grating layer.

[0072] In some embodiments of the present application, the material of the first cover plate 200 may include at least one of glass, resin, and sapphire. In some embodiments of the present application, the material of the first cover plate 200 may be glass, for example, chemically strengthened glass. In some embodiments of the present application, the material of the first cover plate 200 may be Corning GG3 glass (Corning third generation Gorilla Glass) or Corning GG5 glass (Corning fifth generation Gorilla Glass). In other embodiments of the present application, the material of the first cover plate 200 may be sapphire. In other embodiments of the present application, the material of the first cover plate 200 may be resin.

[0073] S300: The surface of the first grating layer after the hydrophilic treatment is away from the first substrate and is in direct contact with the surface of the first cover plate.

[0074] The hydrophilic treated first grating layer 120 is placed away from the surface of the first substrate 110 and in direct contact with the surface of the first cover plate 200, and pre-bonding is completed by relying on hydrophilic groups such as -OH on the surface and hydrogen bonds, so that a certain force is formed between the first cover plate and the first grating layer.

[0075] S400: performing annealing treatment on the first cover plate and the first grating layer.

[0076] After the first grating layer 120 and the first substrate 110 are in direct contact, the first cover plate 200 and the first grating layer 120 are annealed, so that the surfaces where the first cover plate and the first grating layer contact each other form a strong bond, thereby achieving a firm combination of the first cover plate and the first grating layer. There is a large contact area and more supporting points between the first cover plate and the first grating layer. When the first cover plate is subjected to external force, the first cover plate is not easily deformed, and the first grating layer is not easily damaged. The prepared diffraction waveguide module has high reliability.

[0077] In some embodiments of the present application, the temperature of the annealing treatment can be 400°C-1000°C. For example, the temperature of the annealing treatment can be 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, etc. The temperature of the annealing treatment is set within the above range, and the surfaces in contact with the first grating layer and the first substrate can undergo dehydration condensation and other reactions to form strong bonds. For example, Si-Si bonds, Si-O bonds, etc. can be formed, thereby forming a strong bonding force between the first substrate and the first grating layer, which is beneficial to further improve the stability and reliability of the diffraction waveguide module.

[0078] In some embodiments of the present application, the annealing time may be 0.5h-3h, for example, the annealing time may be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, etc. When the annealing time is set within the above range, a strong bond may be formed between the first substrate and the first grating layer, so that the first substrate and the first grating layer are firmly combined.

[0079] The current diffraction waveguide products mainly include three-chip monochrome (RGB), two-chip (RG / GB) color, single-chip color and monochrome products. In order to achieve the miniaturization of AR products and improve the consumer experience, it is urgent to reduce the thickness and weight of the waveguide module. While reducing the thickness and weight of the module, it is also necessary to meet the requirements of waveguide reliability. In view of this, in some embodiments of the present application, reference Figure 4 and Figure 6 The method for preparing the diffractive waveguide module may further include: thinning the first cover plate 200. After the first cover plate is thinned, the overall thickness of the diffractive waveguide module is reduced, which is beneficial to the lightweight and miniaturization of the diffractive waveguide module.

[0080] In some embodiments of the present application, the thinning process may include a chemical mechanical polishing (CMP) process. The chemical mechanical polishing process is performed on the first cover plate to reduce the thickness of the first cover plate, and the surface of the first cover plate after the thinning process is relatively smooth.

[0081] In some embodiments of the present application, the thickness of the first cover plate 200 before thinning may be 0.1 mm-1 mm. For example, the thickness of the first cover plate 200 before thinning may be 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, etc.

[0082] In some embodiments of the present application, the thickness of the first cover plate 200 after thinning may be 0.05 mm-0.3 mm. For example, the thickness of the first cover plate 200 after thinning may be 0.05 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, etc.

[0083] In some embodiments of the present application, reference Figure 7 and Figure 8, the method for preparing a diffraction waveguide module may further include the step of forming at least one second waveguide component 500. The step of forming the second waveguide component 500 is similar to the step of forming the first waveguide component 100, and will not be repeated here. The second waveguide component 500 is located on a side of the first waveguide component 100 away from the first cover plate 200, and the second waveguide component 500 includes a second substrate 510 and a second grating layer 520 located on a side surface of the second substrate 510. The edge area of ​​the second substrate 510 of the second waveguide component 500 closest to the first waveguide component 100 is bonded to the first substrate 110 of the first waveguide component 100 through the first adhesive layer 600, and there is a gap between the second grating layer 520 and the first substrate 110.

[0084] In some embodiments of the present application, reference Figure 7 The method for preparing the diffraction waveguide module also includes the step of forming a second waveguide component 500. After the first cover plate 200 is thinned, the second waveguide component 500 can be attached to the surface of the first substrate 110 on the side away from the first cover plate 200 by frame pasting. The edge area of ​​the second substrate 510 is bonded to the first substrate 110 by the first adhesive layer 600, and there is a gap between the second grating layer 520 and the first substrate 110.

[0085] In other embodiments of the present application, reference Figure 7 The method for preparing the diffraction waveguide module further includes the step of forming two second waveguide components 500, the two second waveguide components 500 are arranged on a side of the first substrate 110 away from the first cover plate 200 by means of frame pasting, the edge area of ​​the second substrate 510 of the second waveguide component 500 close to the first waveguide component 100 is bonded to the first substrate 110 by means of the first adhesive layer 600, and a gap is provided between the second grating layer 520 of the second waveguide component 500 and the first substrate 110. The edge area of ​​the second substrate 510 of the second waveguide component 500 away from the first waveguide component 100 is bonded to the second substrate 510 of the second waveguide component 500 close to the first waveguide component 100 by means of the first adhesive layer 600.

[0086] There is a gap between the second grating layer 520 of the second waveguide component 500 close to the first waveguide component 100 and the first substrate 110, which can at least avoid the problem of light crosstalk to a certain extent. There is a gap between the second grating layer 520 of the second waveguide component 500 far from the first waveguide component 100 and the second substrate 510 of the second waveguide component 500 close to the first waveguide component 100, which can also at least avoid the problem of light crosstalk to a certain extent, which is conducive to improving the user experience.

[0087] It should be noted that Figure 7 and Figure 8In the description, the second waveguide component is bonded to the first substrate after the first cover plate is thinned. In the actual preparation process, the second waveguide component may be bonded to the first substrate first and then the first cover plate may be thinned. Alternatively, a plurality of stacked waveguide components may be formed first and then the first cover plate and the first grating layer of the first waveguide component may be hydrophilic treated and annealed.

[0088] In some embodiments of the present application, reference Figure 4 , Figures 6 to 8 The method for preparing the diffractive waveguide module may further include: attaching a second cover plate 300 to a side of the first substrate 110 away from the first grating layer 120. Thus, the second cover plate can better protect the waveguide component, thereby further improving the reliability of the diffractive waveguide module. Figure 4 and Figure 6 , the second cover plate 300 can be attached to the surface of the first substrate 110 away from the first cover plate 200 through the second adhesive layer 400. In other specific embodiments of the present application, refer to Figure 7 and Figure 8 The second cover plate 300 may be attached to the surface of the second substrate 510 away from the first cover plate 200 through the second adhesive layer 400 .

[0089] In some embodiments of the present application, the second cover plate 300 may be made of glass, resin, sapphire or the like.

[0090] In some embodiments of the present application, the material of the second adhesive layer 400 may be OCR (optically clear resin) or OCA (optical adhesive).

[0091] In some embodiments of the present application, the thickness of the second adhesive layer 400 may be 30 μm-100 μm. For example, the thickness of the second adhesive layer 400 may be 30 μm, 50 μm, 80 μm, 100 μm, etc.

[0092] In general, the diffraction waveguide module is prepared by the method proposed in the present application. A large number of hydrophilic groups can be introduced on the surface of the first cover plate and the surface of the first grating layer by performing hydrophilic treatment on the first cover plate and the first grating layer. The surfaces of the first cover plate and the first grating layer are in direct contact with each other to achieve pre-bonding, so that the first cover plate and the first grating form a certain force through hydroxyl groups, hydrogen bonds, etc. on the surface. After that, through annealing treatment, the contact surfaces of the first cover plate and the first grating layer form a strong bond, thereby achieving a firm combination of the first cover plate and the first grating layer. In addition, the grating in the module prepared by the method is not easily damaged, and the module has high reliability. Furthermore, thinning the first cover plate is conducive to achieving lightweight and miniaturization of the diffraction waveguide module.

[0093] In another aspect of the present application, the present application proposes a diffractive waveguide module. In some embodiments of the present application, the diffractive waveguide module is a diffractive waveguide module prepared by the method described above. The structure of the diffractive waveguide module can be referred to Figure 4 , Figures 6 to 8 The diffraction waveguide module has high reliability, and the first grating layer is not easily damaged when the first cover plate is subjected to external force, which is conducive to improving the user experience.

[0094] In another aspect of the present application, the present application proposes a display device. In some embodiments of the present application, the display device may include the diffractive waveguide module described above. Thus, the display device has all the features and advantages of the diffractive waveguide module described above, which will not be repeated here. In general, the display device has high reliability and good user experience.

[0095] In some embodiments of the present application, the display device may be an AR (augmented reality) glasses. Those skilled in the art should understand that, in addition to the diffractive waveguide module described above, the AR glasses may also include necessary structural parts such as a frame and temples.

[0096] In the description of the present application, the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and do not require that the present application must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0097] In the description of this specification, the description of reference terms "one embodiment", "another embodiment", "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are mutually contradictory. In addition, it should be noted that in this specification, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In addition, in the description of this specification, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0098] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for preparing a diffractive waveguide module, characterized in that: include: forming a first waveguide component, wherein the first waveguide component comprises a first substrate and a first grating layer located on a surface of one side of the first substrate, wherein the first grating layer covers a portion of a surface of the first substrate; Providing a first cover plate, and performing a hydrophilic treatment on the first cover plate and the first grating layer; The surface of the first grating layer after the hydrophilic treatment is away from the first substrate and is in direct contact with the surface of the first cover plate; The first cover plate and the first grating layer are annealed.

2. The method according to claim 1, characterized in that: The hydrophilic treatment includes plasma treatment, and / or the temperature of the annealing treatment is 400° C.-1000° C.; and / or the time of the annealing treatment is 0.5 h-3 h.

3. The method according to claim 1, characterized in that Forming the first waveguide assembly includes: providing a first substrate; Depositing a first material layer on one side surface of the first substrate, wherein the refractive index of the first material layer is 2.0-3.0; The first material layer is etched at least once to form a first grating layer.

4. The method according to claim 3, characterized in that After depositing the first material layer on one side surface of the first substrate, etching the first material layer once comprises: forming a chromium film layer on a surface of the first material layer away from the first substrate; forming a photoresist layer on a surface of the chromium film layer away from the first substrate; exposing and developing the photoresist layer to form a patterned resist layer; Etching the chromium film layer to form a patterned chromium layer, and removing the patterned glue layer; Etching the first material layer to form at least one first grating; At least a portion of the patterned chromium layer is removed.

5. The method according to any one of claims 1 to 4, characterized in that Also includes: The first cover plate is subjected to a thinning process.

6. The method according to claim 5, characterized in that At least one of the following conditions is met: The thinning process includes chemical mechanical polishing; The thickness of the first cover plate before thinning is 0.1 mm-1 mm; The thickness of the first cover plate after thinning is 0.05mm-0.3mm; The material of the first cover plate includes at least one of glass, resin and sapphire; The material of the first substrate includes glass; The thickness of the first substrate is 0.1 mm-3 mm; The material of the first material layer includes at least one of titanium dioxide, silicon nitride, hafnium dioxide, tantalum pentoxide and zirconium dioxide.

7. The method according to claim 1, characterized in that The method further includes the step of forming at least one second waveguide component, wherein the second waveguide component is located on a side of the first waveguide component away from the first cover plate, the second waveguide component includes a second substrate and a second grating layer located on a surface of one side of the second substrate, an edge region of the second substrate of the second waveguide component closest to the first waveguide component is bonded to the first substrate of the first waveguide component through a first adhesive layer, and a gap is provided between the second grating layer and the first substrate.

8. The method according to any one of claims 1 to 4, 6 and 7, characterized in that Also includes: A second cover plate is attached to a side of the first substrate away from the first grating layer.

9. A diffraction waveguide module, characterized in that: The diffraction waveguide module is a diffraction waveguide module prepared by the method described in any one of claims 1-8.

10. A display device, characterized in that: Comprising the diffraction waveguide module as claimed in claim 9.

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