Optical wafer coating process

Abstract

The invention provides an optical wafer coating process, which comprises the following steps of: firstly, coating a first functional film on one surface of an optical wafer, then, imprinting a grating structure on a structural region of an opposite surface of the one surface of the optical wafer, and coating the first functional film on a non-structural region of the opposite surface of the one surface of the optical wafer, the first functional film has an anti-reflection function. The first functional film with the anti-reflection function is plated in the non-structural area, except the grating structural area, in the double-face area of the optical wafer, then the diffraction optical waveguide is prepared through the optical wafer to serve as the AR glasses lens, in the process that a user wears the AR glasses, light rays, reflected into the human eyes through the optical waveguide base body, of an external object are eliminated, and the user experience is improved. Therefore, in the process of observing an image which is output from an optical machine and is coupled out through the diffraction optical waveguide to enter the human eyes, a user does not see that an external object is reflected and imaged through the optical waveguide base body, and the user experience is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of diffraction optical waveguide preparation, and in particular relates to an optical wafer coating process. Background Art

[0002] Augmented reality (AR) technology refers to the use of certain technical means to provide users with additional information in the real world (the so-called "enhancement"). This technology organically combines the images of the virtual world and the scenes of the real world, and deeply integrates the calculated information with the real world, thereby providing users with richer information and immersive experience.

[0003] Augmented reality technology can be implemented through many hardware platforms, the most immersive of which is wearable augmented reality devices, namely AR glasses.

[0004] At present, the more mature AR glasses technology solutions are mainly divided into prism solutions, bi rdbath solutions, free-form surface solutions, off-axis holographic lens solutions and diffraction optical waveguide solutions.

[0005] Exemplarily, the diffraction optical waveguide includes an optical waveguide substrate, an in-coupling grating and an out-coupling grating, wherein the in-coupling grating and the out-coupling grating are arranged on the optical waveguide substrate (generally a glass wafer), and the basic principle thereof is as follows: Figure 1 As shown, the light output by the optical machine (imaging device) is coupled into the grating and coupled into the optical waveguide matrix, and propagates in the optical waveguide matrix by total reflection. Whenever a part of the light is coupled out when encountering the out-coupling grating, the out-coupled light (the solid line in the direction of the human eye in the figure) enters the human eye, so that the same image as the output of the optical machine can be seen. At the same time, the human eye can see the real world scene (the dotted line in the direction of the human eye in the figure). The overlap of the two parts can realize the function of augmented reality.

[0006] However, for the use of the above-mentioned diffraction optical waveguide as an AR glasses lens solution, when the user actually wears the AR glasses, in addition to being able to observe the image output from the optical machine through the diffraction optical waveguide and coupled into the human eye, the human eye can also see the external objects reflected by the optical waveguide matrix to form an image, which reduces the user experience. Summary of the invention

[0007] In order to overcome the defects of the prior art, the present invention provides an optical wafer coating process.

[0008] The present invention is achieved through the following technical solutions:

[0009] The present invention provides an optical wafer coating process, comprising the following steps:

[0010] coating a first functional film on one side of the optical wafer;

[0011] imprinting a grating structure in a structured region on a surface opposite to the one surface of the optical wafer;

[0012] A first functional film is plated on a non-structured area on the opposite side of the one side of the optical wafer.

[0013] Furthermore, the step of coating a first functional film on one side of the optical wafer comprises the following steps:

[0014] Placing the optical wafer in the first coating fixture;

[0015] Fixing the first coating fixture on which the optical wafer is placed in the coating equipment;

[0016] Starting the coating device to alternately coat silicon and titanium on the one side of the optical wafer in a vacuum state, thereby completing coating the first functional film on the one side of the optical wafer;

[0017] Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

[0018] Furthermore, the first coating fixture includes a first base;

[0019] A first groove is formed in the first base, and a first through hole is formed in the bottom of the first groove;

[0020] The side wall of the first groove is clamped to the side wall of the optical wafer, and the bottom edge of the first groove is in contact with the edge position of the one side of the optical wafer.

[0021] Furthermore, the first coating fixture further includes a first clamping block;

[0022] A first clamping portion is provided at the top end of the side wall of the first groove, extending in a direction away from the center position of the first through hole;

[0023] The first clamping block can be clamped in the first clamping portion;

[0024] A protrusion is provided at one end of the first clamping block. When the first clamping block is clamped on the first clamping portion, the protrusion can be clamped with the side wall notch of the optical wafer.

[0025] Furthermore, the first coating fixture further includes a first connecting assembly, and the first connecting assembly includes a first bolt and a first nut;

[0026] A second through hole is formed on the bottom surface of the first clamping portion, and a third through hole is formed in the first clamping block, wherein the third through hole is a threaded hole;

[0027] The first bolt passes through the third through hole and the second through hole in sequence and is connected to the first nut.

[0028] Furthermore, the first coating fixture further includes a second clamping block and a second connecting assembly, and the second connecting assembly includes a second bolt and a second nut;

[0029] The first base defines a fourth through hole, the second clamping block defines a fifth through hole, and the fourth through hole is a threaded hole;

[0030] The second bolt is connected to the second nut through the fourth through hole and the fifth through hole in sequence;

[0031] Furthermore, a positioning portion extends from the side wall of the first through hole toward the side wall of the first groove.

[0032] Furthermore, imprinting a grating structure in a structure region on the opposite side of the one side of the optical wafer comprises the following steps:

[0033] preparing an imprinting master having the grating structure;

[0034] The grating structure of the imprint master is transferred to the soft mold by a nanoimprint process, and the opposite structure of the grating structure is obtained on the soft mold;

[0035] The opposite structure of the grating structure on the soft mold is transferred to the structural region on the opposite side of the one side of the optical wafer through a nanoimprint process, thereby completing the imprinting of the grating structure on the structural region on the opposite side of the one side of the optical wafer.

[0036] Furthermore, the grating structure at least includes an in-coupling grating and an out-coupling grating.

[0037] Furthermore, before coating the first functional film on the non-structural region on the opposite side of the one side of the optical wafer, coating the second functional film on the structural region of the coupling-in grating on the opposite side of the one side of the optical wafer specifically comprises the following steps:

[0038] placing the optical wafer in a second coating fixture;

[0039] Fixing the second coating fixture on which the optical wafer is placed in the coating equipment;

[0040] Starting the coating device, coating titanium on the structure region of the coupling-in grating on the opposite side of the one side of the optical wafer under vacuum, and completing coating a second functional film on the structure region of the coupling-in grating on the opposite side of the one side of the optical wafer;

[0041] Among them, the coating time is controlled at 100-200min, and the coating temperature is controlled at 60-80℃.

[0042] Furthermore, the second coating fixture includes a second base;

[0043] A second groove is formed in the second base, and a sixth through hole is formed in the bottom of the second groove at a set position;

[0044] The side wall of the second groove is clamped to the side wall of the optical wafer, and the bottom edge of the second groove is in contact with the edge position of the opposite surface of the one side of the optical wafer;

[0045] The shape and size of the sixth through hole correspond to and match the structural area of ​​the coupling-in grating.

[0046] Furthermore, the top end of the side wall of the second groove extends in a direction away from the center position of the sixth through hole to form a pick-and-place portion.

[0047] Furthermore, after coating a second functional film on the structural region of the coupling-in grating on the opposite side of the one side of the optical wafer, the method further includes performing optical performance detection on the structural region of the coupling-out grating on the opposite side of the one side of the optical wafer.

[0048] Furthermore, coating a first functional film on a non-structural area on the opposite side of the one side of the optical wafer comprises the following steps:

[0049] Using a positioning fixture, a covering layer is provided in the structural region of the outcoupling grating on the opposite side of the one side of the optical wafer, wherein the covering layer shields the structural region of the outcoupling grating;

[0050] Placing the optical wafer in a third coating fixture, wherein the third coating fixture shields the structure area of ​​the coupling-in grating on the opposite side of the one side of the optical wafer;

[0051] Fixing the third coating fixture for placing the optical wafer in the coating equipment;

[0052] Starting the coating device, alternately coating the non-structural area on the opposite side of the one side of the optical wafer with silicon and titanium in a vacuum state, and completing coating the first functional film on the non-structural area on the opposite side of the one side of the optical wafer;

[0053] Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

[0054] Furthermore, it also includes: a protective layer is provided on the side of the cover layer that is provided on the opposite side of the one side of the optical wafer and contacts with air.

[0055] Furthermore, after the first functional film is plated on the non-structural area of ​​the opposite surface of the one side of the optical wafer, the method further includes:

[0056] The covering layer disposed on the opposite surface of the one surface of the optical wafer is removed.

[0057] Further, the third coating fixture includes a third base;

[0058] A third groove is formed in the third base, and a seventh through hole is formed in the bottom of the third groove;

[0059] The bottom edge of the third groove is extended at a set position toward the center of the seventh through hole to form a shielding portion;

[0060] The side wall of the third groove is clamped to the side wall of the optical wafer, and the bottom edge of the third groove is in contact with the edge position of the opposite surface of the one side of the optical wafer;

[0061] The shielding portion shields the structural region of the coupling-in grating on the opposite side of the one side of the optical wafer.

[0062] Further, the positioning fixture includes a fourth base;

[0063] A fixing platform for placing an optical wafer is arranged inside the top surface of the fourth base, and a positioning piece is arranged at the edge of the top surface of the fourth base.

[0064] Furthermore, the fixing platform is provided with adsorption holes.

[0065] Furthermore, the positioning fixture also includes a sealing bottom plate;

[0066] The top edge of the sealing bottom plate is connected to the bottom edge of the fourth base;

[0067] The top surface of the sealing bottom plate is provided with a fourth groove at the location where the adsorption hole is arranged;

[0068] The sealing bottom plate is provided with a vacuum adsorption channel, one end of the vacuum adsorption channel is communicated with the groove body cavity of the fourth groove, and the other end of the vacuum adsorption channel is communicated with the outer side of the side wall of the sealing bottom plate.

[0069] Furthermore, the method of using a positioning fixture to set a covering layer on the structure area of ​​the outcoupling grating on the opposite side of the one side of the optical wafer, wherein the covering layer shields the structure area of ​​the outcoupling grating, comprises the following steps:

[0070] Cutting the cover layer so that the size of the cover layer matches the structural area of ​​the outcoupling grating;

[0071] The cut covering layer is arranged on one side at a set position of the positioning layer; the positioning layer is provided with a positioning hole matching the positioning piece;

[0072] Placing an optical wafer on the top surface of the fixing table, with one side of the optical wafer in contact with the top surface of the fixing table;

[0073] The positioning holes of the positioning layer are matched and connected to the positioning piece so that the covering layer on the positioning layer is arranged in the structural area of ​​the outcoupling grating on the opposite side of the one side of the optical wafer, and the covering layer shields the structural area of ​​the outcoupling grating.

[0074] Furthermore,

[0075] After the cut covering layer is arranged at the set position of the positioning layer, an isolation layer is arranged on the side of the covering layer contacting the air;

[0076] Before the positioning holes of the positioning layer are matched and connected to the positioning piece, the isolation layer provided on the covering layer is removed.

[0077] Furthermore, before transferring the grating structure of the imprint master to the soft mold by the nanoimprint process and obtaining the reverse structure of the grating structure on the soft mold, it also includes:

[0078] A flexible glass is arranged on the opposite side of the soft film transfer grating structure.

[0079] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0080] The present invention provides an optical wafer coating process, firstly, a first functional film is coated on one side of an optical wafer, then a grating structure is embossed on a structural region on the opposite side of one side of the optical wafer, and further, the first functional film is coated on a non-structural region on the opposite side of one side of the optical wafer. The first functional film has the function of increasing transmittance and reducing reflection, that is, by coating the functional film on the non-structural region except the grating structure region on both sides of the optical wafer, and then using the optical wafer to prepare a diffraction optical waveguide as an AR glasses lens, when the user wears the AR glasses, the light reflected by the external objects through the optical waveguide matrix into the human eye is eliminated, so that the user's human eye will not see the external objects reflected by the optical waveguide matrix in the process of observing the image output from the optical machine and coupled out through the diffraction optical waveguide into the human eye, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0082] Figure 1 A schematic diagram of the working principle of an existing diffractive optical waveguide is shown as an example;

[0083] Figure 2 It is a schematic diagram of the overall process of the optical wafer coating process of the present invention;

[0084] Figure 3 is a schematic diagram of a first exemplary structure of a first coating fixture at a first angle;

[0085] Figure 4 is a schematic diagram of a second exemplary structure of the first coating fixture at a first angle;

[0086] Figure 5 is a schematic diagram of a third exemplary structure of the first coating fixture at a first angle;

[0087] Figure 6 is a schematic diagram of an example structure of the first coating fixture at a second angle;

[0088] Figure 7 is a schematic diagram of an example structure of a first clamping block;

[0089] Figure 8 is a schematic structural diagram of a first example of an optical wafer;

[0090] Fig. 9 is a schematic diagram of an example structure of a second clamping block;

[0091] Fig.10 is a schematic structural diagram of a second example of an optical wafer;

[0092] Fig.11 is a schematic diagram of an example structure of a second coating fixture at a first angle;

[0093] Fig.12 is a schematic diagram of an example structure of a second coating fixture at a second angle;

[0094] Fig.13 A schematic diagram of a pre-cut optical wafer of an example;

[0095] Fig.14 It is a schematic structural diagram of the positioning fixture of the first example at a first angle;

[0096] Fig.15 It is a schematic structural diagram of the positioning fixture of the first example at a second angle;

[0097] Fig.16 is a structural schematic diagram of a positioning fixture of a second example;

[0098] Fig.17 is a schematic diagram of the structure of an example sealing bottom plate;

[0099] Fig.18 for Fig.17A partial cross-sectional view of the sealing bottom plate shown;

[0100] Fig.19 A schematic diagram of the positioning fixture structure for placing optical wafers;

[0101] Fig. 20 is a schematic structural diagram of a positioning layer having a covering layer;

[0102] Fig.21 is a schematic structural diagram of the third coating fixture at a first angle;

[0103] Fig. 22 It is a schematic diagram of the structure of the third coating fixture at a second angle.

[0104] Among them, 1-first base, 2-first groove, 3-first through hole, 4-first clamping block, 4-1-protrusion, 5-first clamping part, 6-optical wafer, 7-second through hole, 8-third through hole, 9-second clamping block, 10-fourth through hole, 11-fifth through hole, 12-positioning part, 13-second base, 14-second groove, 15-sixth through hole, 16-pick-and-place part, 17-coupled grating, 18-coupled grating, 19-fourth base, 20-positioning piece, 21-fixed platform, 22-adsorption hole, 23-sealing bottom plate, 24-first connecting hole, 25-second connecting hole, 26-fourth groove, 27-first vacuum adsorption channel, 28-second vacuum adsorption channel, 29-covering layer, 30-positioning layer, 31-positioning hole, 32-third base, 33-third groove, 34-seventh through hole, 35-shielding part. DETAILED DESCRIPTION

[0105] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0106] Currently, diffraction optical waveguides are used as the lens solution for AR glasses. When users actually wear AR glasses, in addition to being able to observe the image output from the optical machine through the diffraction optical waveguide and entering the human eye, the human eye can also see the image reflected by the optical waveguide matrix from external objects, which reduces the user experience.

[0107] In order to solve the above problems, the present invention provides an optical wafer coating process, such as Figure 2 As shown, the overall concept is as follows:

[0108] S1: coating a first functional film on one side of the optical wafer.

[0109] S2: imprinting a grating structure in a structure region on a surface opposite to the above-mentioned surface of the optical wafer, wherein the grating structure at least includes an in-coupling grating and an out-coupling grating.

[0110] S3: coating a second functional film on a structure region of the coupling-in grating on a surface opposite to the above-mentioned surface of the optical wafer.

[0111] S4 performs optical performance detection on the structure area of ​​the outcoupling grating on the opposite side of the above-mentioned one side of the optical wafer.

[0112] S5: coating a first functional film on a non-structured area on the opposite side of the one side of the optical wafer.

[0113] Exemplarily, S1 deposits a first functional film on one side of an optical wafer, comprising the following steps:

[0114] S1-1 places the optical wafer in the first coating fixture.

[0115] For example,

[0116] like Figure 3 As shown, the first coating fixture comprises a first base 1 , a first groove 2 is formed in the first base 1 , and a first through hole 3 is formed in the bottom of the first groove 2 .

[0117] The side wall of the first groove 2 is clamped with the side wall of the optical wafer, and the bottom edge of the first groove 2 is in contact with the edge position of the above-mentioned one side of the optical wafer.

[0118] As a preferred embodiment, the first coating fixture may further include a first clamping block 4 (such as Figure 7 As shown), the first clamping portion 5 is extended from the top of the side wall of the first groove 2 toward the direction away from the center position of the first through hole 3, and the first clamping block 4 can be clamped in the first clamping portion 5 (as shown Figure 4 shown).

[0119] A protrusion 4-1 (such as Figure 7 As shown), when the first clamping block is clamped on the first clamping portion, the protrusion can be clamped with the side wall notch of the optical wafer.

[0120] The above structure can realize that the first coating fixture can be used for the optical wafer 6 (such as Figure 8 As shown in the figure, the optical wafer is relatively fixed to prevent the optical wafer from rotating in the first coating fixture.

[0121] In the above embodiment, in order to improve the connection performance between the first clamping block and the first clamping portion, the first coating fixture may further include a first connection component, and the first connection component may include a first bolt and a first nut. The bottom surface of the first clamping portion 5 is provided with a second through hole 7 (such as Figure 3 , Figure 6As shown), a third through hole 8 is provided in the first clamping block 4 (as shown Figure 7 As shown), the third through hole is a threaded hole, and the first bolt passes through the third through hole and the second through hole in sequence and is connected to the first nut.

[0122] As a preferred embodiment, the first coating fixture may further include a second clamping block 9 (such as Fig. 9 As shown) and a second connecting component, the second connecting component example includes a second bolt and a second nut.

[0123] The first base has a fourth through hole 10 (such as Figure 6 As shown), the second clamping block defines a fifth through hole 11 (as shown Figure 5 as well as Fig. 9 As shown), the fourth through hole is a threaded hole, and the second bolt is connected to the second nut through the fourth through hole and the fifth through hole in sequence.

[0124] Through the above design, the first coating fixture can be used to coat irregular optical wafers (such as Fig.10 The optical wafer 6) whose local edge is a straight line is relatively fixed to prevent the optical wafer from rotating in the first coating fixture.

[0125] As a further preferred embodiment, the side wall of the first through hole 3 extends a positioning portion 12 (such as Figure 3 As shown in the figure, the positioning portion 12 is designed in combination with the characteristic points of the optical wafer (such as the side wall notch of the optical wafer or the straight line design of the local edge), so as to facilitate the determination of the side of the optical wafer on which the first functional film is coated, thereby assisting subsequent operators to imprint the grating structure on the opposite side of the side of the optical wafer on which the first functional film is coated.

[0126] S1-2 fixes the first coating fixture on which the optical wafer is placed in the coating equipment.

[0127] The coating equipment can adopt the existing coating equipment.

[0128] Exemplarily, the coating equipment may include a coating chamber, a heating device, a vacuuming device, an electron beam evaporation source, and an optical wafer fixing device.

[0129] The optical wafer fixing device is fixedly arranged at the upper end of the coating chamber and is used for placing the optical wafer.

[0130] The heating device is fixedly arranged on the top inner wall of the coating chamber. For example, the heating device can be a heating wire, which is arranged on the top inner wall of the coating chamber in a curved arrangement, and the heating wire and the top inner wall of the coating chamber are fixedly connected by welding or the like.

[0131] The vacuum pumping equipment is communicated with the coating chamber, and the vacuum pumping equipment adopts existing equipment.

[0132] The electron beam evaporation source is fixed at the bottom of the coating chamber. The electron beam evaporation source uses existing equipment, including a cathode for emitting electrons, an electron accelerating electrode, and an anode for heating the film material. The heating film material is selected according to the coating film material.

[0133] S1-3 starts the coating equipment, and alternately coats silicon and titanium on one side of the optical wafer under a vacuum state. The alternating coating of silicon and titanium on one side of the optical wafer can be achieved by alternately replacing the heating film material of the electron beam evaporation source, thereby completing the coating of the first functional film on the above-mentioned one side of the optical wafer. The first functional film has the function of increasing transmission and reducing reflection.

[0134] Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

[0135] Exemplarily, S2, imprinting a grating structure in a structure region on the opposite side of the above-mentioned one side of the optical wafer, may include the following steps:

[0136] S2-1 Prepare an imprinting master having the above-mentioned grating structure.

[0137] For example,

[0138] A photoresist having a set thickness is spin-coated on the substrate to obtain a substrate provided with the photoresist.

[0139] The photoresist on the substrate is subjected to interference exposure operation to obtain a photoresist body grating with changed properties on the substrate.

[0140] The photoresist grating with changed properties on the substrate is developed to obtain a substrate with a photoresist relief grating mask.

[0141] The photoresist relief grating mask on the substrate is ion-beam etched to transfer the topography of the photoresist relief grating mask to the substrate, thereby obtaining an imprint master having the grating structure.

[0142] S2-2 transfers the grating structure of the imprint master to the soft mold through the nanoimprint process, and obtains the opposite structure of the grating structure on the soft mold.

[0143] For example,

[0144] The soft film substrate is connected to the fixing frame through an elastic component, and the fixing frame on which the soft film substrate is arranged is placed above the glue-spreading stage.

[0145] Place the lower bottom surface of the imprint master on the glue-spreading stage, and spin-coat the imprint glue on the upper bottom surface of the imprint master.

[0146] The fixed frame is moved down to a position where it fits the imprint template of the glue-spreading platform through the lifting mechanism.

[0147] A pressure roller is used to apply pressure to the soft film substrate in the fixed frame so that the embossing glue is filled into the grating structure of the embossing master, and the reverse structure of the grating structure is obtained on the embossing glue.

[0148] The embossing adhesive with the reverse structure of the grating structure is transferred to the soft mold substrate by ultraviolet light curing and demoulding to obtain a soft film with the reverse structure of the grating structure.

[0149] It should be noted that during the above operation, the soft film substrate is subject to the tension of the elastic component, the pressure of the pressure roller and the influence of the external environment. The soft film substrate is prone to deformation, which causes the grating transfer structure on the soft film to deform, thereby causing the grating structure period subsequently transferred to the optical wafer through the soft film to deviate from the theoretically set period, which can easily cause abnormal optical indicators of the optical wafer.

[0150] In order to solve this problem, the present invention arranges a flexible glass on the opposite side of the soft film transfer grating structure. That is, after the soft film substrate is connected to the fixed frame through the elastic component, the flexible glass is arranged on the side of the soft film substrate in contact with the pressure roller. The flexible glass is not easily deformed by force and is not easily affected by the external environment (temperature, humidity). Compared with the existing single soft film substrate, the combined design of the soft film substrate and the flexible glass can prevent the soft film substrate from being deformed.

[0151] S2-3 transfers the opposite structure of the grating structure on the soft mold to the structural region on the opposite side of the above-mentioned one side of the optical wafer through a nanoimprint process, thereby completing the imprinting of the grating structure in the structural region on the opposite side of the above-mentioned one side of the optical wafer.

[0152] For example,

[0153] On the opposite side of the above-mentioned one side of the optical wafer, a tackifier and a product glue are spin-coated in sequence, and a soft mold having a structure opposite to the grating structure is bonded to the product glue of the optical wafer. Pressure is applied to allow the product glue to fill the opposite structure of the grating structure of the soft mold, and a grating structure is obtained on the product glue. The soft mold having a structure opposite to the grating structure is separated from the product glue having the grating structure by ultraviolet light curing and demolding, thereby completing the grating structure imprinting in the structural area on the opposite side of the above-mentioned one side of the optical wafer.

[0154] Exemplarily, S3 is to deposit a second functional film on a structure region of the coupling-in grating on the opposite side of the above-mentioned side of the optical wafer, comprising the following steps:

[0155] S3-1 places the optical wafer in the second coating fixture.

[0156] For example,

[0157] like Fig.11As shown, the second coating fixture comprises a second base 13, a second groove 14 is formed in the second base 13, and a sixth through hole 15 (such as Fig.12 Here, the setting position of the sixth through hole matches and corresponds to the setting position of the coupling-in grating of the optical wafer, and the shape and size of the sixth through hole matches and corresponds to the shape and size of the coupling-in grating of the optical wafer.

[0158] The side wall of the second groove 14 is clamped with the side wall of the optical wafer, and the bottom edge of the second groove 14 is in contact with the edge position of the opposite surface of one side of the optical wafer.

[0159] The top of the side wall of the second groove 14 extends in a direction away from the center of the sixth through hole 15 to form a pick-up and place portion 16, which is convenient for taking and placing the optical wafer from the second coating fixture. At the same time, the pick-up and place portion can be designed in combination with the characteristic points of the optical wafer (such as the side wall notch of the optical wafer) to facilitate determining the side of the optical wafer where the coupling grating area is set to be coated with the second functional film.

[0160] S3-2 fixes the second coating fixture for placing the optical wafer in the coating equipment, wherein the coating equipment can be an existing coating equipment.

[0161] S3-3 starts the coating equipment, and coats titanium on the structural area of ​​the coupling grating on the opposite side of the above-mentioned one side of the optical wafer under vacuum state, thereby completing the coating of the second functional film on the structural area of ​​the coupling grating on the opposite side of the above-mentioned one side of the optical wafer.

[0162] Among them, the coating time is controlled at 100-200min, and the coating temperature is controlled at 60-80℃.

[0163] The second functional film is plated on the coupling-in grating area to increase the diffraction efficiency of the diffracted light at the working order when the incident light is diffracted by the coupling-in grating in a reflection manner.

[0164] Exemplarily, S4 performs optical performance detection on a structure area of ​​an outcoupling grating on the opposite side of the above-mentioned one side of the optical wafer, including:

[0165] The optical wafer is fixed in an optical performance testing device, and the optical performance testing device is used to perform a light efficiency test on the structure area of ​​the out-coupling grating of the optical wafer. If the current optical wafer passes the light efficiency test, the subsequent process flow continues. If the current optical wafer fails the light efficiency test, it is analyzed whether there are improvement measures. If not, the current optical wafer is scrapped. Compared with performing a light efficiency test after preparing a diffractive optical waveguide having the form of an AR glasses lens from the optical wafer, performing a light efficiency test at this stage can reduce the investment cost of preparing a diffractive optical waveguide with qualified light efficiency and improve the production efficiency of a diffractive optical waveguide with qualified light efficiency.

[0166] It should be noted that, in the process of performing optical performance testing on the structure area of ​​the outcoupling grating on the opposite side of the above-mentioned one side of the optical wafer, in order to enable the optical performance testing device to fix the optical wafer with the grating structure, it may be necessary to pre-cut the optical wafer with the grating structure, such as Fig.13 , which is a schematic diagram of an example of a pre-cut optical wafer. The grating structure of the optical wafer 6 in the figure includes an in-coupling grating 17 and an out-coupling grating 18 .

[0167] Exemplarily, S5 deposits a first functional film on a non-structured area on the opposite side of the above-mentioned one side of the optical wafer, comprising the following steps:

[0168] S5-1 uses a positioning fixture to set a covering layer on the structural area of ​​the out-coupling grating on the opposite side of the above-mentioned one side of the optical wafer, and the covering layer shields the structural area of ​​the out-coupling grating.

[0169] For example, Fig.14 As shown, the positioning fixture includes a fourth base 19, a positioning member 20 is arranged at the edge of the top surface of the fourth base 19, a fixing platform 21 is arranged inside the top surface of the fourth base 19, and the fixing platform 21 is provided with an adsorption hole 22. The fixing platform 21 vacuum adsorbs and fixes the above-mentioned side of the optical wafer 6 (such as Fig.19 shown).

[0170] In order to improve the adsorption and fixing effect of the fixing table on the optical wafer, the positioning fixture can further include a sealing bottom plate 23, the top edge of the sealing bottom plate 23 is connected to the bottom edge of the fourth base 19 (such as Fig.16 As shown). For example, a first connection hole 24 (as shown) can be opened on the top edge of the sealing bottom plate 23. Fig.17 A second connection hole 25 is provided at the bottom edge of the fourth base 19 (as shown in FIG. Fig.15 As shown), the sealing base plate can be fixedly connected to the fourth base through the first connecting hole and the second connecting hole.

[0171] The top surface of the sealing bottom plate 23 is provided with a fourth groove 26 (such as Fig.17 shown).

[0172] The sealing bottom plate is provided with a vacuum adsorption channel, one end of the vacuum adsorption channel is connected to the groove body chamber of the fourth groove, and the other end of the vacuum adsorption channel is connected to the outer side of the side wall of the sealing bottom plate. Fig.18 As shown, the vacuum adsorption channel includes a first vacuum adsorption channel 27 and a second vacuum adsorption channel 28. One end of the first vacuum adsorption channel 27 is connected to the bottom of the fourth groove 26, and the other end of the first vacuum adsorption channel 27 is connected to one end of the second vacuum adsorption channel 28. The other end of the second vacuum adsorption channel 28 is connected to the side wall hole of the sealing bottom plate 23.

[0173] A vacuum pump is connected to the other end of the second vacuum adsorption channel through an adsorption pipeline to achieve the adsorption and fixing effect of the fixing table on the optical wafer.

[0174] Exemplarily, using the positioning fixture to set a cover layer on the structure area of ​​the outcoupling grating on the opposite side of the one side of the optical wafer, the cover layer shielding the structure area of ​​the outcoupling grating, comprises the following steps:

[0175] S5-1-1 cuts the covering layer so that the size of the covering layer matches the structural area of ​​the outcoupling grating.

[0176] Exemplarily, the covering layer may adopt an existing UV anti-adhesion film.

[0177] S5-1-2 Set a positioning hole 31 matching the positioning piece of the positioning fixture on the positioning layer 30, and set one side of the cut covering layer 29 at a set position of the positioning layer 30 (such as Fig. 20 The setting position of the cover layer on the positioning layer needs to satisfy: after the positioning layer is matched and connected with the positioning piece of the positioning fixture through the positioning hole, the position of the cover layer on the positioning layer is set corresponding to the structural area of ​​the coupling grating on the optical wafer of the fixed table in the positioning fixture.

[0178] Exemplarily, the positioning layer may be an existing film layer.

[0179] An isolation layer is arranged on the side of the covering layer contacting the air. When the covering layer on the positioning layer is not used to shield the outcoupling grating area of ​​the optical wafer, the isolation layer can isolate and protect the side of the covering layer on the positioning layer exposed to the air.

[0180] Exemplarily, the isolation layer may be an existing film layer.

[0181] S5-1-3 Place an optical wafer on the top surface of the fixing table, and the above-mentioned one side of the optical wafer contacts the top surface of the fixing table.

[0182] S5-1-4 Tear off the isolation layer on the covering layer, match the positioning holes of the positioning layer to the positioning pieces in the positioning fixture, so that the covering layer in the positioning layer is exposed to air on one side thereof and is arranged on the structural area of ​​the out-coupling grating on the opposite side of the above-mentioned side of the optical wafer. The covering layer blocks the structural area of ​​the out-coupling grating, and then the positioning layer is torn off.

[0183] Preferably, since the non-structural area on one side of the optical wafer where the structural area is set needs to be placed in a coating device for a high-temperature coating operation, and the covering layer of the optical wafer in the structural area of ​​the out-coupling grating needs to be removed after the coating operation is completed, the covering layer needs to have high temperature resistance requirements, the covering layer is easy to remove after high-temperature baking, and it is not easy to have residual glue in the structural area of ​​the out-coupling grating of the optical wafer.

[0184] Taking the existing UV anti-sticking film as an example,

[0185] 1. Attach the preliminarily selected UV anti-adhesion films to the optical wafers respectively and bake them in an oven at a temperature above 100 degrees Celsius for 24 hours.

[0186] 2. Use UV lamp to irradiate the UV anti-adhesion film on the optical wafer for 1-2 minutes.

[0187] 3. Remove the UV anti-adhesion film on the optical wafer.

[0188] 4. Use a microscope to observe whether there is any residual glue on the optical wafer in the attachment area of ​​the UV anti-adhesion film. If there is residual glue on the optical wafer in the attachment area of ​​the UV anti-adhesion film, the UV anti-adhesion film attached to the optical wafer does not meet the use requirements. If there is no residual glue on the optical wafer in the attachment area of ​​the UV anti-adhesion film, the UV anti-adhesion film attached to the optical wafer meets the use requirements.

[0189] S5-2: placing the optical wafer in a third coating jig, and the third coating jig shields the structure area of ​​the coupling-in grating on the opposite side of the above-mentioned one side of the optical wafer.

[0190] For example, Fig.21 As shown, the third coating fixture includes a third base 32 , a third groove 33 is defined in the third base 32 , and a seventh through hole 34 is defined in the bottom of the third groove 33 .

[0191] The bottom edge of the third groove 33 is extended at a set position toward the center of the seventh through hole 34 to form a shielding portion 35 (such as Fig. 22 shown).

[0192] The side wall of the third groove 33 is clamped with the side wall of the optical wafer, and the bottom edge of the third groove 33 is in contact with the edge position of the opposite surface of the optical wafer to the above-mentioned one surface.

[0193] The shielding portion 35 shields the structure region of the coupling-in grating on the opposite side of the above-mentioned side of the optical wafer.

[0194] The setting position of the shielding portion at the groove bottom edge of the third groove needs to satisfy the following requirement: after the optical wafer is clamped in the third groove, the shielding portion can shield the structural region of the coupling grating of the optical wafer.

[0195] S5-3: A protective layer is provided on the side of the optical wafer opposite to the above-mentioned side where the covering layer contacts the air.

[0196] Exemplarily, the protective layer may be an existing black polyester film.

[0197] By providing a protective layer on the side of the optical wafer that contacts the air, the following functions are achieved:

[0198] After the first functional film is subsequently coated on the non-structural area opposite to the above-mentioned side of the optical wafer in the coating equipment, in the process of removing the shielding layer from the structural area of ​​the out-coupling grating of the optical wafer, it is avoided that the structural area of ​​the out-coupling grating has residues of the shielding layer. For example, when the shielding layer is made of the existing UV anti-adhesion film, in the process of removing the anti-adhesion film from the structural area of ​​the out-coupling grating of the optical wafer, it is avoided that the structural area of ​​the out-coupling grating has residual glue of the anti-adhesion film and affects the out-coupling imaging effect of the out-coupling grating area.

[0199] S5-4 fixes the third coating fixture for placing the optical wafer in the coating equipment. The coating equipment can be an existing coating equipment.

[0200] S5-5 starts the coating equipment, and alternately coats silicon and titanium on the non-structural area opposite to the above-mentioned one side of the optical wafer under a vacuum state. The alternating coating of silicon and titanium on one side of the optical wafer can be achieved by alternately replacing the heating film material of the electron beam evaporation source, thereby completing the coating of the first functional film on the non-structural area opposite to the above-mentioned one side of the optical wafer.

[0201] Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

[0202] S5-6 After coating the first functional film on the non-structural area of ​​the surface opposite to the above-mentioned one side of the optical wafer, the covering layer on the surface opposite to the above-mentioned one side of the optical wafer is removed.

[0203] Taking the existing UV anti-sticking film as an example,

[0204] The opposite side of the optical wafer to the above one side is irradiated with a UV lamp, and then the anti-sticking film is torn off from the opposite side of the optical wafer to the above one side.

[0205] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art can still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. An optical wafer coating process, characterized in that: The steps include: coating a first functional film on one side of the optical wafer; imprinting a grating structure in a structured region on a surface opposite to the one surface of the optical wafer; A first functional film is plated on a non-structured area on the opposite side of the one side of the optical wafer.

2. The optical wafer coating process according to claim 1, characterized in that: The step of coating a first functional film on one side of the optical wafer comprises the following steps: Placing the optical wafer in the first coating fixture; Fixing the first coating fixture on which the optical wafer is placed in the coating equipment; Starting the coating device to alternately coat silicon and titanium on the one side of the optical wafer in a vacuum state, thereby completing coating the first functional film on the one side of the optical wafer; Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

3. The optical wafer coating process according to claim 2, characterized in that: The first coating fixture comprises a first base; A first groove is formed in the first base, and a first through hole is formed in the bottom of the first groove; The side wall of the first groove is clamped to the side wall of the optical wafer, and the bottom edge of the first groove is in contact with the edge position of the one side of the optical wafer.

4. The optical wafer coating process according to claim 3, characterized in that: The first coating fixture further includes a first clamping block; A first clamping portion is provided at the top end of the side wall of the first groove, extending in a direction away from the center position of the first through hole; The first clamping block can be clamped in the first clamping portion; A protrusion is provided at one end of the first clamping block. When the first clamping block is clamped on the first clamping portion, the protrusion can be clamped with the side wall notch of the optical wafer.

5. The optical wafer coating process according to claim 4, characterized in that: The first coating fixture further includes a first connecting assembly, and the first connecting assembly includes a first bolt and a first nut; A second through hole is formed on the bottom surface of the first clamping portion, and a third through hole is formed in the first clamping block, wherein the third through hole is a threaded hole; The first bolt passes through the third through hole and the second through hole in sequence and is connected to the first nut.

6. The optical wafer coating process according to claim 3, characterized in that: The first coating fixture further includes a second clamping block and a second connecting assembly, and the second connecting assembly includes a second bolt and a second nut; The first base defines a fourth through hole, the second clamping block defines a fifth through hole, and the fourth through hole is a threaded hole; The second bolt is connected to the second nut through the fourth through hole and the fifth through hole in sequence.

7. The optical wafer coating process according to claim 3, characterized in that: The side wall of the first through hole extends toward the side wall of the first groove to form a positioning portion.

8. The optical wafer coating process according to claim 1, characterized in that: Imprinting a grating structure in a structure region on the opposite side of the one side of the optical wafer comprises the following steps: preparing an imprinting master having the grating structure; The grating structure of the imprint master is transferred to the soft mold by a nanoimprint process, and the opposite structure of the grating structure is obtained on the soft mold; The opposite structure of the grating structure on the soft mold is transferred to the structural region on the opposite side of the one side of the optical wafer through a nanoimprint process, thereby completing the imprinting of the grating structure on the structural region on the opposite side of the one side of the optical wafer.

9. The optical wafer coating process according to claim 1, characterized in that: The grating structure at least includes an incoupling grating and an outcoupling grating.

10. The optical wafer coating process according to claim 9, characterized in that: Before coating the first functional film on the non-structured region on the opposite side of the one side of the optical wafer, coating the second functional film on the structured region of the coupling-in grating on the opposite side of the one side of the optical wafer specifically includes the following steps: placing the optical wafer in a second coating fixture; Fixing the second coating fixture on which the optical wafer is placed in the coating equipment; Starting the coating device, coating titanium on the structure region of the coupling-in grating on the opposite side of the one side of the optical wafer under vacuum, and completing coating a second functional film on the structure region of the coupling-in grating on the opposite side of the one side of the optical wafer; Among them, the coating time is controlled at 100-200min, and the coating temperature is controlled at 60-80℃.

11. The optical wafer coating process according to claim 10, characterized in that: The second coating fixture includes a second base; A second groove is formed in the second base, and a sixth through hole is formed in the bottom of the second groove at a set position; The side wall of the second groove is clamped to the side wall of the optical wafer, and the bottom edge of the second groove is in contact with the edge position of the opposite surface of the one side of the optical wafer; The shape and size of the sixth through hole correspond to and match the structural area of ​​the coupling-in grating.

12. The optical wafer coating process according to claim 11, characterized in that: The top end of the side wall of the second groove extends in a direction away from the center position of the sixth through hole to form a pick-and-place portion.

13. The optical wafer coating process according to claim 10, characterized in that: After coating a second functional film on the structure region of the coupling-in grating on the opposite side of the one side of the optical wafer, the method further includes performing optical performance detection on the structure region of the coupling-out grating on the opposite side of the one side of the optical wafer.

14. The optical wafer coating process according to claim 9, characterized in that: Plating a first functional film on a non-structured area on the opposite side of the one side of the optical wafer comprises the following steps: Using a positioning fixture, a covering layer is provided in the structural region of the outcoupling grating on the opposite side of the one side of the optical wafer, wherein the covering layer shields the structural region of the outcoupling grating; Placing the optical wafer in a third coating fixture, wherein the third coating fixture shields the structure area of ​​the coupling-in grating on the opposite side of the one side of the optical wafer; Fixing the third coating fixture for placing the optical wafer in the coating equipment; Starting the coating device, alternately coating the non-structural area on the opposite side of the one side of the optical wafer with silicon and titanium in a vacuum state, and completing coating the first functional film on the non-structural area on the opposite side of the one side of the optical wafer; Among them, the coating time is controlled at 60-100min, and the coating temperature is controlled at 70-100℃.

15. The optical wafer coating process according to claim 14, characterized in that: Also includes: A protective layer is disposed on the side of the optical wafer opposite to the one side thereof that contacts air.

16. The optical wafer coating process according to claim 14, characterized in that: After the first functional film is plated on the non-structural area of ​​the opposite surface of the one side of the optical wafer, the method further includes: The covering layer disposed on the opposite surface of the one surface of the optical wafer is removed.

17. The optical wafer coating process according to claim 14, characterized in that: The third coating fixture comprises a third base; A third groove is formed in the third base, and a seventh through hole is formed in the bottom of the third groove; The bottom edge of the third groove is extended at a set position toward the center of the seventh through hole to form a shielding portion; The side wall of the third groove is clamped to the side wall of the optical wafer, and the bottom edge of the third groove is in contact with the edge position of the opposite surface of the one side of the optical wafer; The shielding portion shields the structural region of the coupling-in grating on the opposite side of the one side of the optical wafer.

18. The optical wafer coating process according to claim 14, characterized in that: The positioning fixture includes a fourth base; A fixing platform for placing an optical wafer is arranged inside the top surface of the fourth base, and a positioning piece is arranged at the edge of the top surface of the fourth base.

19. The optical wafer coating process according to claim 18, characterized in that: The fixing platform is provided with adsorption holes.

20. The optical wafer coating process according to claim 19, characterized in that: The positioning fixture also includes a sealing bottom plate; The top edge of the sealing bottom plate is connected to the bottom edge of the fourth base; The top surface of the sealing bottom plate is provided with a fourth groove at the location where the adsorption hole is arranged; The sealing bottom plate is provided with a vacuum adsorption channel, one end of the vacuum adsorption channel is communicated with the groove body cavity of the fourth groove, and the other end of the vacuum adsorption channel is communicated with the outer side of the side wall of the sealing bottom plate.

21. The optical wafer coating process according to claim 18, characterized in that: The method of using a positioning fixture to set a covering layer on the structure area of ​​the outcoupling grating on the opposite side of the one side of the optical wafer, wherein the covering layer shields the structure area of ​​the outcoupling grating, comprises the following steps: Cutting the cover layer so that the size of the cover layer matches the structural area of ​​the outcoupling grating; The cut covering layer is arranged on one side at a set position of the positioning layer; the positioning layer is provided with a positioning hole matching the positioning piece; Placing an optical wafer on the top surface of the fixing table, with one side of the optical wafer in contact with the top surface of the fixing table; The positioning holes of the positioning layer are matched and connected to the positioning piece, so that the covering layer on the positioning layer is arranged in the structural area of ​​the outcoupling grating on the opposite side of the one side of the optical wafer, and the covering layer shields the structural area of ​​the outcoupling grating.

22. The optical wafer coating process according to claim 21, characterized in that: After the cut covering layer is arranged at the set position of the positioning layer, an isolation layer is arranged on the side of the covering layer contacting the air; Before the positioning holes of the positioning layer are matched and connected to the positioning piece, the isolation layer provided on the covering layer is removed.

23. The optical wafer coating process according to claim 8, characterized in that: Before the grating structure of the imprint master is transferred to the soft mold by the nanoimprint process to obtain the reverse structure of the grating structure on the soft mold, the method further comprises: A flexible glass is arranged on the opposite side of the soft film transfer grating structure.

Images