Method for manufacturing a diffractive optical waveguide and diffractive optical waveguide

Abstract

The present invention provides a method for manufacturing a diffractive optical waveguide and a diffractive optical waveguide, which can solve the problem of customized cover plates, facilitate shortening the product processing cycle, and reduce the product manufacturing cost. The method for manufacturing the diffractive optical waveguide includes the steps of: respectively attaching a cover plate glass wafer to the surface of an optical waveguide wafer to obtain a wafer attachment assembly; cutting and dicing the wafer attachment assembly to obtain at least one semi-finished optical waveguide; and performing ion exchange strengthening on the semi-finished optical waveguide to obtain a diffractive optical waveguide.

Description

Technical Field

[0001] The present invention relates to the technical field of optical waveguides, and particularly to a manufacturing method of a diffractive optical waveguide and a diffractive optical waveguide. Background Art

[0002] Currently, for the diffractive optical waveguides used in augmented reality glasses, it is usually necessary to bond the strengthened glass cover plates on the front and back to protect the surface micro-nano structures of the diffractive optical waveguides and prevent foreign dirt from damaging the light propagation path at the micro-nano structures. The existing strengthened glass cover plates are first customized into a special shape from the unstrengthened glass raw materials according to the shape of the optical waveguide, then the ion exchange is performed on the processed glass raw materials to complete the strengthening of the glass, and finally the completed strengthened glass cover plates are bonded to the front and back of the optical waveguide.

[0003] However, diffractive optical waveguides usually correspond to a variety of different shape designs. If the cover plates are customized each time, it will lead to overly fragmented material requirements, and multiple sets of processing jigs need to be prepared for each product, which is not convenient for the management of the product supply chain and the product processing production line, resulting in a significant increase in the product processing cycle and cost. In addition, customizing the strengthened glass cover plates with special shapes also requires one-to-one stacking on the front and back of the optical waveguide, which will lead to low stacking efficiency, is not conducive to the control of alignment accuracy and parallelism, and results in poor product quality. Summary of the Invention

[0004] One advantage of the present invention is to provide a manufacturing method of a diffractive optical waveguide and a diffractive optical waveguide, which can solve the problem of cover plate customization, facilitate shortening the product processing cycle, and reduce the product manufacturing cost.

[0005] Another advantage of the present invention is to provide a manufacturing method of a diffractive optical waveguide and a diffractive optical waveguide. In one embodiment of the present invention, the manufacturing method of the diffractive optical waveguide can improve the stacking efficiency while obtaining better alignment accuracy and parallelism, which is convenient for improving the product quality.

[0006] Another advantage of the present invention is to provide a manufacturing method of a diffractive optical waveguide and a diffractive optical waveguide. In one embodiment of the present invention, the manufacturing method of the diffractive optical waveguide can use a thinner cover plate glass, eliminating problems such as air gaps and frame adhesive lines, so as to significantly reduce the product thickness and weight.

[0007] Another advantage of the present invention is to provide a manufacturing method of a diffractive optical waveguide and a diffractive optical waveguide. In one embodiment of the present invention, the manufacturing method of the diffractive optical waveguide can completely solve the problem of poor alignment accuracy when stacking the cover plates, reducing the theoretical alignment deviation to zero.

[0008] Another advantage of the present invention is to provide a method for manufacturing a diffractive optical waveguide and a diffractive optical waveguide. In one embodiment of the present invention, the method for manufacturing the diffractive optical waveguide can ensure that the strength of the strengthened glass cover plate reaches the level of a common glass cover plate.

[0009] Another advantage of the present invention is to provide a method for manufacturing a diffractive optical waveguide and a diffractive optical waveguide. In one embodiment of the present invention, the method for manufacturing the diffractive optical waveguide can reduce the number of ink coating operations while eliminating the problems of poor ink coating quality and even inability to perform edge ink coating.

[0010] Another advantage of the present invention is to provide a method for manufacturing a diffractive optical waveguide and a diffractive optical waveguide. To achieve the above object, expensive materials or complex structures are not required in the present invention. Therefore, the present invention successfully and effectively provides a solution that not only provides a simple method for manufacturing a diffractive optical waveguide and a diffractive optical waveguide, but also increases the practicability and reliability of the method for manufacturing the diffractive optical waveguide and the diffractive optical waveguide.

[0011] To achieve at least one of the above advantages or other advantages and objects of the present invention, the present invention provides a method for manufacturing a diffractive optical waveguide, including the steps of:

[0012] Respectively attaching a cover glass wafer to the surface of an optical waveguide wafer to obtain a wafer attachment assembly;

[0013] Cutting and dicing the wafer attachment assembly to obtain at least one semi-finished optical waveguide; and

[0014] Performing ion exchange strengthening on the semi-finished optical waveguide to obtain a diffractive optical waveguide.

[0015] According to an embodiment of the present application, the thickness of the cover glass wafer is less than or equal to 0.15 mm.

[0016] According to an embodiment of the present application, the step of respectively attaching the cover glass wafer to opposite sides of the optical waveguide wafer to obtain a wafer attachment assembly includes the steps of:

[0017] Coating glue on opposite sides of the optical waveguide wafer by means of spin coating or slot coating; and

[0018] In a vacuum environment, fully attaching the cover glass wafer to opposite sides of the optical waveguide wafer to form the wafer attachment assembly after the glue is cured.

[0019] According to an embodiment of the present application, the coating thickness of the glue is less than or equal to 15 μm.

[0020] According to an embodiment of the present application, the refractive index of the glue is less than or equal to 1.4.

[0021] According to an embodiment of the present application, the wafer bonding assembly is cut and separated in one go by laser cutting or wire cutting.

[0022] According to an embodiment of the present application, the ion exchange depth is the thickness of the cover glass wafer.

[0023] According to an embodiment of the present application, the method for manufacturing the diffraction optical waveguide further includes the step of:

[0024] Inking the edge of the diffraction optical waveguide.

[0025] According to another aspect of the present application, the present application further provides a diffraction optical waveguide, which is prepared by the method for manufacturing the diffraction optical waveguide described in any one of the above.

[0026] According to an embodiment of the present application, the thickness of the diffraction optical waveguide is less than or equal to 1 mm. Description of the Drawings

[0027] Figure 1 is a schematic flow chart of the method for manufacturing a diffraction optical waveguide according to an embodiment of the present application;

[0028] Figure 2 shows a schematic flow chart of the wafer bonding step in the method for manufacturing a diffraction optical waveguide according to the above embodiment of the present application;

[0029] Figure 3 shows an example of the process flow of the method for manufacturing a diffraction optical waveguide according to the above embodiment of the present application;

[0030] Figure 4 shows a specific example of the method for manufacturing a diffraction optical waveguide according to the above embodiment of the present application. Detailed Embodiments

[0031] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0032] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0033] In the present invention, the term "a" in the claims and the specification should be understood as "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. Unless it is clearly indicated in the disclosure of the present invention that the number of the element is only one, the term "a" should not be understood as being unique or single, and the term "a" should not be construed as a limitation on the number.

[0034] In the description of the present invention, it should be understood that terms such as "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do 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, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0036] Considering that existing diffractive optical waveguides usually correspond to a variety of different appearance designs, customizing the cover plate each time will result in too fragmented material requirements, and each product needs to prepare multiple sets of processing jigs, which is not convenient for the management of the product supply chain and product processing production line, thereby causing a substantial increase in product processing cycle and cost. In order to solve this problem, the present application creatively proposes a manufacturing method and a diffractive optical waveguide for a diffractive optical waveguide, which can solve the problem of cover plate customization, facilitate shortening the product processing cycle, and reduce product manufacturing costs.

[0037] Specifically, refer to the accompanying drawings of the specification of this application. Figure 1 According to an embodiment of the present application, a method for manufacturing a diffractive optical waveguide is provided, which may include the steps of:

[0038] S100: respectively bonding the cover glass wafer to the surface of the optical waveguide wafer to obtain a wafer bonding assembly;

[0039] S200: cutting and splitting the wafer bonding assembly to obtain at least one optical waveguide semi-finished product; and

[0040] S300: performing ion exchange strengthening on the optical waveguide semi-finished product to obtain a diffractive optical waveguide.

[0041] It is worth noting that since the present application first bonds the cover glass wafer to the surface of the optical waveguide wafer, and then performs ion exchange strengthening after cutting the splits, the present application does not need to customize the cover for optical waveguides of different appearance designs, thus avoiding excessively fragmented material requirements, facilitating the management of the product supply chain and product processing production line, and helping to shorten the product processing cycle. At the same time, compared to the prior art of bonding the strengthened glass cover to the diffraction optical waveguide one-to-one, the present application can improve the stacking efficiency through wafer bonding technology, obtain better alignment accuracy and parallelism, facilitate improving product quality, and completely solve the problem of poor alignment accuracy when stacking the cover, reducing the theoretical alignment deviation to zero.

[0042] More specifically, the thickness of the cover glass wafer of the present application can be less than or equal to 0.15 mm, so as to significantly reduce the thickness and weight of the product. It is understandable that compared with the thickness of the existing strengthened glass cover which is generally greater than 0.3 mm, the present application can use a thinner cover glass because it uses a whole piece of unstrengthened glass wafer for bonding, so that the weight and thickness of the product can be greatly reduced.

[0043] Alternatively, if Figure 2 As shown, step S100 of the method for manufacturing a diffractive optical waveguide of the present application may include the following steps:

[0044] S110: applying glue to two opposite sides of the optical waveguide wafer by spin coating or slit coating; and

[0045] S120: In a vacuum environment, fully bond the cover glass wafer to the opposite two sides of the optical waveguide wafer to form the wafer bonding assembly after the glue cures.

[0046] It should be noted that, compared with the frame bonding method used in the existing solution, on the one hand, the present application uses spin coating or slit coating methods to obtain a smooth glue line, and on the other hand, bonding in a vacuum environment can eliminate air gaps, so as to obtain a glue layer with a thickness uniformity of less than 1%, thereby obtaining better parallelism.

[0047] It can be understood that in step S100 of the present application, for the optical waveguide wafer with a double-sided grating structure, glue can be first coated on the front side of the optical waveguide wafer, and after bonding one cover glass wafer to the front side of the optical waveguide wafer, glue can be then coated on the back side of the optical waveguide wafer to bond the other cover glass wafer to the back side of the optical waveguide wafer; or glue can be first coated on the back side of the optical waveguide wafer, and after bonding one cover glass wafer to the back side of the optical waveguide wafer, glue can be then coated on the front side of the optical waveguide wafer to bond the other cover glass wafer to the front side of the optical waveguide wafer, as long as the full bonding of the front and back sides of the optical waveguide wafer can be completed, and the present application will not elaborate on this.

[0048] In addition, for the optical waveguide wafer with a single-sided grating structure, only glue needs to be coated on the side with the grating structure to fully bond the cover glass wafer, which helps to further reduce the thickness of the diffractive optical waveguide.

[0049] Optionally, in step S110 of the present application, the coating thickness of the glue can be less than or equal to 15um, so as to further compress the product thickness and weight.

[0050] In addition, in step S110 of the present application, the coated glue has a low refractive index to meet the total internal reflection condition of the optical waveguide. For example, the refractive index of the glue can be less than or equal to 1.4.

[0051] Optionally, the material of the glue can be a special modified glue resistant to high temperature, such as modified epoxy resin.

[0052] Optionally, in step S200 of the manufacturing method of the diffractive optical waveguide of the present application: one-time cutting and dicing operations can be performed, but not limited to, by laser cutting. It can be understood that in other examples of the present application, the wafer bonding assembly can also be cut and diced by wire cutting in one time, both of which can eliminate the alignment accuracy problem when bonding the cover plate and ensure that the theoretical alignment deviation is reduced to zero.

[0053] Optionally, in step S300 of the method for manufacturing a diffractive optical waveguide according to the present application: the ion exchange depth is preferably implemented as the thickness of the cover glass wafer, so that the cover glasses on opposite sides of the optical waveguide in the semi-finished optical waveguide are strengthened to form the strengthened cover glasses in the diffractive optical waveguide, ensuring that the strengthened cover glasses on opposite sides of the optical waveguide in the diffractive optical waveguide have the same strength level as ordinary strengthened glass.

[0054] According to the above embodiments of the present application, as Figure 1 shown, the method for manufacturing the diffractive optical waveguide may further include the steps of:

[0055] S400: Apply ink to the edges of the diffractive optical waveguide.

[0056] It should be noted that compared with the prior art where the edge of the strengthened glass cover and the optical waveguide need to be inked separately, that is, inked three times successively; the present application only needs to perform one ink application, which can not only reduce the number of ink application operations, but also eliminate the problem of poor ink application quality caused by the small thickness of the strengthened glass cover and the optical waveguide, and even the inability to perform edge ink application.

[0057] Exemplarily, as Figure 3 and Figure 4 shown, the present application takes an optical waveguide wafer with a double-sided grating structure having a diameter of 12 inches and a thickness of 0.6 mm, a glue with a refractive index of 1.4, and an ultra-thin unstrengthened cover glass wafer with a diameter of 12 inches and a thickness of 0.1 mm as an example to illustrate the above method for manufacturing the diffractive optical waveguide. The specific process flow is as follows:

[0058] 1) Spin-coat a low-refractive-index glue on the front side of the optical waveguide wafer with a diameter of 12 inches and a thickness of 0.6 mm. The glue coating thickness is 15 microns, and the refractive index of the glue is 1.4;

[0059] 2) Bond the ultra-thin unstrengthened cover glass wafer with a diameter of 12 inches and a thickness of 0.1 mm to the front side of the optical waveguide wafer in a vacuum environment;

[0060] 3) Flip the wafer assembly after the front side is bonded;

[0061] 4) Spin-coat a low-refractive-index glue on the back side. The glue coating thickness is 15 microns, and the refractive index of the glue is 1.4;

[0062] 5) Bond the ultra-thin unstrengthened cover glass wafer with a diameter of 12 inches and a thickness of 0.1 mm to the back side of the optical waveguide wafer in a vacuum environment to obtain a wafer bonding assembly;

[0063] 6) After the wafers with front and back overlapped (i.e., wafer bonding components) are subjected to dicing and breaking, single-sided optical waveguides with unstrengthened glass cover plates on both sides are formed (i.e., optical waveguide semi-finished products);

[0064] 7) Ion exchange strengthening is carried out to obtain a diffractive optical waveguide, and the ion exchange depth is 0.1 mm, which is the thickness of the ultra-thin glass cover plate;

[0065] 8) The single-sided optical waveguides with strengthened glass cover plates on both sides (i.e., diffractive optical waveguides) are coated with black ink on the edges to obtain the final optical waveguide products.

[0066] It should be noted that the manufacturing method of the diffractive optical waveguide of the present application has at least the following advantages:

[0067] 1) Since the optical waveguide wafer usually has multiple diffractive optical waveguides after processing, and the optical waveguide wafer and the cover glass wafer are fully bonded in a vacuum environment using a low refractive index glue, the manufacturing method of the diffractive optical waveguide of the present application can not only greatly improve the lamination efficiency, but also use a thinner cover glass (the thickness can be less than 0.15 mm); at the same time, the manufacturing method of the diffractive optical waveguide of the present application coats the glue by spin coating or slot coating, which can eliminate the air gap and the problem of frameless glue application line, so that the thickness uniformity of the pre-coated glue can be less than 1%, in order to obtain better parallelism.

[0068] 2) Since after the full lamination is completed, the wafer bonding components composed of the cover glass wafers and the optical waveguide wafers on both sides are subjected to dicing and breaking operations at one time using a laser or wire cutting, the manufacturing method of the diffractive optical waveguide of the present application can eliminate the problem of alignment accuracy when laminating the cover plates, so that the theoretical alignment deviation of this method is zero.

[0069] 3) Since the ion exchange strengthening of the ultra-thin glass cover plates on both sides is carried out only after the dicing and breaking are completed, and the ion exchange depth is the thickness of the ultra-thin glass, the manufacturing method of the diffractive optical waveguide of the present application can ensure that the ultra-thin glass obtains the same strength level as the ordinary glass cover plate.

[0070] 4) Since the edge inking operation of the three-layer structure optical waveguide (i.e., diffractive optical waveguide) is carried out only after the chemical strengthening, the manufacturing method of the diffractive optical waveguide of the present application can reduce the number of inking operations, and at the same time eliminate the problem that when the thickness of the cover glass is less than or equal to 0.3 mm, the inking quality is poor or even the edge inking cannot be carried out.

[0071] It is worth mentioning that according to another aspect of the present application, an embodiment of the present application further provides a diffractive optical waveguide, which can be prepared by the manufacturing method of the diffractive optical waveguide described above.

[0072] Optionally, the thickness of the diffractive optical waveguide prepared in this application can be compressed to less than 1 mm, that is, the thickness of the diffractive optical waveguide can be less than or equal to 1 mm, which helps to meet the development requirements of the current thin and light electronic devices.

[0073] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0074] The above embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a diffractive optical waveguide, characterized in that, Including the steps of: Respectively bonding a cover glass wafer to the surfaces of an optical waveguide wafer to obtain a wafer bonding assembly; Cutting and dicing the wafer bonding assembly to obtain at least one optical waveguide semi-finished product; And Performing ion exchange strengthening on the optical waveguide semi-finished product to obtain a diffractive optical waveguide; Wherein, the step of respectively bonding the cover glass wafer to the opposite surfaces of the optical waveguide wafer to obtain a wafer bonding assembly includes the steps of: Coating glue on the opposite surfaces of the optical waveguide wafer by means of spin coating or slot coating; And In a vacuum environment, fully bonding the cover glass wafer to the opposite surfaces of the optical waveguide wafer to form the wafer bonding assembly after the glue is cured.

2. The manufacturing method of the diffractive optical waveguide according to claim 1, wherein The thickness of the cover glass wafer is less than or equal to 0.15 mm.

3. The manufacturing method of the diffractive optical waveguide according to claim 1, characterized in that, The coating thickness of the glue is less than or equal to 15 μm.

4. The manufacturing method of the diffractive optical waveguide according to claim 1, characterized in that, The refractive index of the glue is less than or equal to 1.

4.

5. The manufacturing method of the diffractive optical waveguide according to claim 1, characterized in that Performing one-time cutting and dicing on the wafer bonding assembly by means of laser cutting or wire cutting.

6. The manufacturing method of the diffractive optical waveguide according to claim 1, characterized in that, The ion exchange depth is the thickness of the cover glass wafer.

7. The manufacturing method of the diffractive optical waveguide according to any one of claims 1 to 6, characterized in that, It further includes the step of: Performing edge inking on the diffractive optical waveguide.

8. A diffractive optical waveguide, characterized in that, The diffractive optical waveguide is prepared by the manufacturing method of the diffractive optical waveguide according to any one of claims 1 to 7.

9. The diffractive optical waveguide according to claim 8, wherein The thickness of the diffractive optical waveguide is less than or equal to 1 mm.

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