A high-power optical zoom "multi-fold" periscope prism and a processing method thereof

Abstract

The application discloses a kind of to realize high optical zoom " multi-fold " periscopic prism and its processing method.The application adopts semiconductor process technology, and multiple patterning film layers can be high-precision aligned using exposure to identify the same mark reference, and the highest alignment accuracy can reach hundred nanometer level, while the alignment accuracy of the product patterning film layer processed by the existing gluing equipment CCD identification method is about 20um, which can effectively avoid the loss of light flux in the process of prism light transmission caused by the shift of patterning film layer, and the abnormal stray light caused by the shift affects the imaging quality, and the process can realize multi-fold prism processing, which can be applied to mobile phones, and the super-long optical path can be " folded " in the narrow space, to realize super-high magnification optical zoom, excellent image quality, while maintaining the relative lightness of the body.

Description

Technical Field

[0001] This invention relates to the field of optical element processing technology, and in particular to a high-magnification optical zoom "multi-fold" periscope prism and its processing method. Background Technology

[0002] With the continued growth in demand for thinner and lighter mobile devices and higher-performance photography, achieving high-magnification, high-quality optical zoom within limited camera body space has become a key challenge. Traditional upright telephoto lenses, due to the significant conflict between module height and body thickness, are no longer sufficient to meet these requirements. To address this, the industry has widely adopted a periscope lens structure, using prisms to fold the light path, constructing a longer focal length optical path in the horizontal space—a design known as "single reflection" or "triple reflection." To further pursue the ultimate focal length, optical path designs employing multiple reflections (such as "five reflections") have emerged, aiming to more effectively compress the light path and achieve ultra-long focal lengths.

[0003] To achieve the five-fold refraction scheme, a multi-layer bonding process is usually adopted, which requires high precision in the alignment of the patterned film layers of the bonding layer. Existing process solutions often use fixtures for fixed alignment or CCD alignment of the bonding equipment, which has poor precision and is difficult to control. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this invention designs a high-magnification optical zoom "multi-fold" periscope prism and its processing method.

[0005] The present invention adopts the following technical solution: A method for fabricating a high-magnification optical zoom "multi-fold" periscope prism, characterized by the following steps: S1. Select the first, second, third, and fourth optical lenses with the same refractive index and perform surface processing. S2. Laser marking is performed on the second optical lens so that there is a alignment mark on each side of the second optical lens; S3, Patterning of the second optical lens: First, the first surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right marks on the substrate are identified so that the left and right marks on the photomask are aligned with the substrate marks. Then, the coated product is subjected to adhesive removal and ultrasonic cleaning to complete the patterned film processing of the first surface of the second optical lens. The second surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right film marks of the second optical lens are identified for alignment. Then, adhesive removal and ultrasonic cleaning are performed to complete the patterned film processing of the second surface of the second optical lens. S4. Bonding the second and third optical lenses: Using an adhesive with the same refractive index as the optical lenses, a first bonding layer is formed. The second and third optical lenses, which have completed the patterned film layers on both sides, are then bonded together and cured. S5. Patterned film processing of the third optical lens: The assembled second and third optical lenses after bonding are coated with adhesive, exposed, developed and coated with black film. The patterned film is processed on the surface of the third optical lens of the assembly. During the exposure of the surface of the third optical lens, the left and right film marks of the second optical lens are identified for alignment. Then, the adhesive is removed and ultrasonic cleaning is performed to complete the patterned film processing of the third optical lens. S6. Bonding the second and third optical lens assembly to the fourth or first optical lens: Using an adhesive with the same refractive index as the optical lens, a second adhesive layer is formed to bond the second and third optical lens assembly to the fourth optical lens and then cure it; then using an adhesive with the same refractive index as the optical lens, a third adhesive layer is formed to bond the second, third, and fourth optical lens assembly to the first optical lens and then cure it. S7. Cutting and processing: The large optical lens after bonding is laser-cut or wire-cut into strip prisms of the required shape. During cutting, the CCD identifies the alignment mark of the left and right film layers on the second optical lens. S8. Perform surface and shape processing on the strip prism to ensure that the product shape and size meet the design requirements.

[0006] Preferably, in step S1, the surface processing of the first optical lens, the second optical lens, the third optical lens, and the fourth optical lens involves wire cutting, grinding, and polishing. The surface roughness of the polished lens is Ra < 0.5 nm, TTV < 3 μm, and PV ≤ 25 μm.

[0007] Preferably, the patterned film layer has a concave cross-section, and the inner frame edge of the patterned film layer is designed with multiple sets of arc-shaped protrusions evenly arranged.

[0008] Preferably, in step S3, the alignment accuracy of the left and right marks on the photomask and the substrate mark during exposure alignment is <2µm.

[0009] Preferably, in step S3, the positional accuracy of the patterned film layers on both sides of the second optical lens is controlled within ±2µm.

[0010] Preferably, the curing process uses UV curing with a curing energy of 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at a temperature of 80-120°C for 0.5-5 hours.

[0011] Preferably, in step S5, the positional accuracy of the patterned film layer between the third optical lens and the second optical lens is controlled within ±2µm.

[0012] Preferably, in step S7, the positional accuracy of the left and right film alignment marks on the second optical lens identified by the CCD is within ±10µm.

[0013] Preferably, in step S8, the surface and shape processing of the strip prism includes grinding and polishing the cut strip prism, milling, polishing, roughening, screen printing, coating, and slitting the strip prism.

[0014] A periscope prism for achieving high-magnification optical zoom includes a first optical lens, a second optical lens, a third optical lens, and a fourth optical lens with the same refractive index. The surfaces of the second and third optical lenses are coated with patterned films. The first, second, third, and fourth optical lenses are fixed together by an adhesive layer.

[0015] The beneficial effects of this invention are as follows: This invention adopts semiconductor manufacturing process, and multiple patterned film layers can achieve high-precision alignment by using exposure to identify the same mark reference. The alignment accuracy can reach up to the level of hundreds of nanometers. In contrast, the alignment accuracy of patterned film layers in existing products processed by bonding equipment and CCD recognition is around 20um. This can effectively avoid the loss of light flux during prism light transmission caused by patterned film layer misalignment, as well as the impact on image quality caused by stray light abnormalities due to misalignment. This process can realize the processing of multi-fold prisms. When applied to mobile phones, ultra-long optical paths can be "folded" in a narrow space, achieving ultra-high magnification optical zoom and excellent image quality, while maintaining a relatively thin and light body. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of one structure of the periscope prism in this invention; Figure 2 This is a schematic diagram of one structure of the patterned film layer in this invention; In the figure: 1. First optical lens, 2. Second optical lens, 3. Third optical lens, 4. Fourth optical lens, 5. First adhesive layer, 6. Second adhesive layer, 7. Third adhesive layer, 8. First patterned film layer, 9. Second patterned film layer, 10. Third patterned film layer. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1As shown, a method for processing a high-magnification optical zoom "multi-fold" periscope prism is disclosed, wherein the prism comprises: a first optical lens 1, a second optical lens 2, a third optical lens 3, a fourth optical lens 4, a first adhesive layer 5, a second adhesive layer 6, a third adhesive layer 7, a first patterned film layer 8, a second patterned film layer 9, and a third patterned film layer 10. The first patterned film layer 8 and the second patterned film layer 9 are disposed on both sides of the second optical lens 2, and the third patterned film layer 10 is disposed on the surface of the third optical lens 3. The second optical lens 2 and the third optical lens 3 are bonded together by the first adhesive layer 5, the third optical lens 3 and the fourth optical lens 4 are bonded together by the second adhesive layer 6, and the first optical lens 1 and the second optical lens 2 are bonded together by the third adhesive layer 7. In this embodiment, the first, second, third, and fourth optical lenses are H-Bak7 with a refractive index of 1.568. The patterned film is a low-reflection, low-transmittance black film, coated on the surfaces of the second and third optical lenses. To suppress concentrated diffraction caused by sharp straight edges of the film (leading to ghosting and reduced contrast), the inner frame edge of the patterned film is designed with rounded protrusions (e.g., ...). Figure 2 As shown in the figure, when light passes through the effective light-transmitting area, this design will cause the diffracted light to disperse and cancel each other out, thereby converting the interference energy into weak and uniform background noise, effectively improving the image quality and transparency; the refractive index of all adhesive layer materials is 1.568.

[0018] The fabrication process for this periscope prism is as follows: 1. Optical lens processing: Select suitable transparent materials such as optical glass or quartz as the first, second, third, and fourth optical lenses. Perform wire cutting, grinding, and polishing on the first, second, third, and fourth optical lenses. The surface roughness of the polished lenses is Ra < 0.5 nm, TTV < 3 μm, and PV ≤ 25 μm (Ra refers to the surface roughness of the optical lens, TTV refers to the total dispersion of the optical lens thickness, and PV value refers to the difference between the highest and lowest points on the surface of the optical lens). 2. Laser marking is performed on the second optical lens to ensure that there is a alignment mark on each side of the second optical lens; 3. Processing of the patterned coating layer for the second optical lens: a. First, the first surface of the second optical lens is coated with adhesive, exposed, developed, and coated with a black film (first patterned film layer). During exposure, the left and right marks on the substrate are identified, so that the left and right marks on the photomask are aligned with the substrate marks, with an alignment accuracy of <2µm. Then, the coated product is subjected to adhesive removal and ultrasonic cleaning, thereby completing the patterning of the first surface of the second optical lens. The film thickness is 1.3µm. b. Apply adhesive, expose, develop and coat a black film (second patterned film layer) to the second surface of the second optical lens. During exposure, identify the left and right film layer marks of the second optical lens for alignment. Then, remove the adhesive and perform ultrasonic cleaning to complete the patterning process of the second surface of the second optical lens. The positional accuracy of the two patterns of the second optical lens can be controlled within ±2um. 4. Bonding the Second and Third Optical Lenses: Using adhesive with the same refractive index as the optical lenses, the second and third optical lenses, after completing the patterned film layers on both sides, are bonded together (first bonding layer) and cured. The curing energy is 50,000 mJ / cm². After curing, the product undergoes high-temperature annealing at 80-120°C for 0.5-5 hours. Annealing promotes residual reactions. In areas not exposed to UV radiation or with insufficient light (such as shaded areas or deep layers), unreacted active groups (monomers, double bonds, etc.) remain. Heating provides these groups with additional energy, enabling them to overcome energy barriers and continue reacting, thereby increasing the final conversion rate. Simultaneously, it releases internal stress. UV curing is a rapid process; the molecular chains are instantly "frozen" and fixed, accumulating significant shrinkage and structural stress internally. Heating allows the polymer chain segments to become mobile, relaxing and rearranging, making the entire cross-linked network structure more uniform and stable. 5. Patterned Coating Processing of the Third Optical Lens: The assembled second and third optical lenses, after bonding, undergo processes such as adhesive application, exposure, development, coating, adhesive removal, and ultrasonic cleaning to complete the patterned coating processing (third patterned coating). The patterned coating is processed on the surface of the third optical lens of the assembly. During exposure on the surface of the third optical lens, the left and right coating marks of the second optical lens are identified for alignment. The positional accuracy of the first surface pattern of the third optical lens and the second optical lens can be controlled within ±2µm. 6. Bonding the second and third optical lens assemblies to the fourth or first optical lens: Use an adhesive with the same refractive index as the optical lens to bond the second and third optical lens assemblies to the fourth optical lens (second adhesive layer) and cure it. The curing energy is 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at 80~120℃ for 0.5~5 hours. Then, use an adhesive with the same refractive index as the optical lens to bond the second, third, and fourth optical lens assemblies to the first optical lens (third adhesive layer) and cure it. The curing energy is 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at 80~120℃ for 0.5~5 hours. 7. Optical Lens Bonding Process: The patterned first and second optical lenses are bonded together using adhesive with the same refractive index as the optical lenses and then cured. The curing energy is 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at a temperature of 80~120℃ for 0.5~5 hours. 8. Cutting and processing: The large optical lens after bonding is laser-cut or wire-cut into strip prisms of the required shape. During cutting, the CCD identifies the left and right film alignment marks on the second optical lens, with a positional accuracy of ±10um. 9. Grinding and polishing of strip prisms: The cut strip prisms are ground and polished to ensure surface smoothness and flatness. The surface roughness of the product is less than 0.5nm, PV is less than 0.3um, and the depth of the glue joint pit is ±10nm. 10. Machining of strip prism shape: Milling, polishing, roughening and other processes are performed on the strip prism to ensure that the product shape and size meet the design requirements; 11. Screen printing: Screen printing is performed on the strip prism according to the design requirements. After screen printing, heat curing is carried out in a dust-free oven. The baking temperature is 100~150℃ and the baking time is 30~180min.

[0019] 12. Coating: According to the optical design requirements, perform optical thin film processing on the silkscreened elongated prism; 13. Slitting: The strip prism is slid into the final required prism.

[0020] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A method for fabricating a high-magnification optical zoom "multi-fold" periscope prism, characterized in that, Includes the following steps: S1. Select the first, second, third, and fourth optical lenses with the same refractive index and perform surface processing. S2. Laser marking is performed on the second optical lens so that there is a alignment mark on each side of the second optical lens; S3, Patterning of the second optical lens: First, the first surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right marks on the substrate are identified so that the left and right marks on the photomask are aligned with the substrate marks. Then, the coated product is subjected to adhesive removal and ultrasonic cleaning to complete the patterned film processing of the first surface of the second optical lens. The second surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right film marks of the second optical lens are identified for alignment. Then, adhesive removal and ultrasonic cleaning are performed to complete the patterned film processing of the second surface of the second optical lens. S4. Bonding the second and third optical lenses: Using an adhesive with the same refractive index as the optical lenses, a first bonding layer is formed. The second and third optical lenses, which have completed the patterned film layers on both sides, are then bonded together and cured. S5. Patterned film processing of the third optical lens: The assembled second and third optical lenses after bonding are coated with adhesive, exposed, developed and coated with black film. The patterned film is processed on the surface of the third optical lens of the assembly. During the exposure of the surface of the third optical lens, the left and right film marks of the second optical lens are identified for alignment. Then, the adhesive is removed and ultrasonic cleaning is performed to complete the patterned film processing of the third optical lens. S6. Bonding the second and third optical lens assembly to the fourth or first optical lens: Using an adhesive with the same refractive index as the optical lens, a second adhesive layer is formed to bond the second and third optical lens assembly to the fourth optical lens and then cure it; then using an adhesive with the same refractive index as the optical lens, a third adhesive layer is formed to bond the second, third, and fourth optical lens assembly to the first optical lens and then cure it. S7. Cutting and processing: The large optical lens after bonding is laser-cut or wire-cut into strip prisms of the required shape. During cutting, the CCD identifies the alignment mark of the left and right film layers on the second optical lens. S8. Perform surface and shape processing on the strip prism to ensure that the product shape and size meet the design requirements.

2. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S1, the surface processing of the first optical lens, the second optical lens, the third optical lens, and the fourth optical lens involves wire cutting, grinding, and polishing. The surface roughness of the polished lenses is Ra < 0.5 nm, TTV < 3 μm, and PV ≤ 25 μm.

3. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, The patterned membrane layer has a concave cross-section, and the inner frame edge of the patterned membrane layer is designed with multiple sets of arc-shaped protrusions evenly arranged.

4. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S3, the alignment accuracy of the left and right marks on the photomask and the substrate mark during exposure alignment is <2µm.

5. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S3, the positional accuracy of the patterned film layers on both sides of the second optical lens is controlled within ±2µm.

6. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, The curing process uses UV curing with a curing energy of 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at a temperature of 80~120℃ for 0.5~5 hours.

7. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S5, the positional accuracy of the patterned film layer between the third optical lens and the second optical lens is controlled within ±2µm.

8. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S7, the positional accuracy of the left and right film alignment marks on the second optical lens identified by the CCD is ±10µm.

9. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S8, the surface and shape processing of the strip prism includes grinding and polishing the cut strip prism, milling, polishing, roughening, screen printing, coating and slitting.

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