Air-permeable dustproof structure of a glue-free optical fiber array coupler

Abstract

This application relates to the technical field of optical communication device packaging, and in particular to a breathable and dustproof structure for a glue-free fiber optic array coupler. The structure includes a modified ePTFE film strip, a composite adhesive layer, micro-support bumps, and a circumferential hydrophobic protective layer. The modified ePTFE film strip covers the periphery of the junction between the fiber optic array unit and the lens array, and its surface is treated with hydrophobic and oleophobic modification. The composite adhesive layer is coated on both sides of the modified ePTFE film strip and is a composite structure of a fluorine coupling agent undercoat and a low-stress, low-exudation silicone layer. The modified ePTFE film strip is sealed and bonded to the body surfaces of the fiber optic array unit and the lens array through the composite adhesive layer, forming a semi-closed protective cavity above the glue-free light-transmitting area. This application achieves all-around anti-pollution effect and stable performance, improves structural vibration resistance and reliability, achieves stress-free protection, ensures long-term stable coupling accuracy between the fiber optic array unit and the lens array, and has high adaptability.

Description

Technical Field

[0001] This application relates to the technical field of optical communication device packaging, and in particular to a breathable and dustproof structure for a glue-free fiber array coupler. Background Technology

[0002] In high-speed optical communication fields such as 5G, data center optical interconnects, and 6G pre-research, the precise coupling of fiber optic array units and lens arrays is a core technology for achieving low-loss and highly stable optical signal transmission in optical modules. The coupling accuracy directly determines the transmission efficiency and performance of optical devices. The trends towards high density, miniaturization, and long lifespan place increasingly stringent demands on the coupling process of fiber optic array units and lens arrays. Traditional coupling processes commonly use UV-cured epoxy resin to bond and fix the fiber optic array units and lens arrays. While this process achieves mechanical fixation and initial sealing, becoming a traditional solution for optical communication device packaging, epoxy resin has inherent technical defects. Its curing process and temperature changes generate unavoidable thermal stress, easily leading to micro-deformation of optical components. Furthermore, long-term use can cause aging and yellowing, altering the refractive index of the optical path. Simultaneously, the refractive index of epoxy resin is highly sensitive to temperature, significantly limiting the temperature adaptability and long-term operational reliability of optical modules.

[0003] A search revealed Chinese Patent Publication No. CN120972329B, which discloses an integrated fiber optic coupling device and equipment. The device includes a beam combining module and a coupling filter module integrated within a housing. The beam combining module polarizes and combines a laser beam, which is then coupled into a fiber combiner via a first fiber and output as a second fiber. This second fiber is then filtered by a cladding light filtering unit and output through a nozzle. The coupling filter module contains multiple fixed cavities with curved walls. The first fiber at the input end of the fiber combiner and the second fiber at the output end are respectively fixed in curvature by adhering to the corresponding curved walls before being output.

[0004] Regarding the aforementioned technologies, the inventors have discovered the following drawbacks: Existing technologies employ simple dustproof structures such as ordinary filters or non-porous dust covers, or simple ventilation structures. While these simple dustproof structures can block dust, they obstruct gas exchange between the encapsulation interior and the external environment. This prevents the release of trace amounts of moisture and volatile substances from the materials, leading to rapid condensation during temperature cycling, which obstructs the optical path and causes signal degradation. Although simple ventilation structures can prevent condensation, they lack an effective dust barrier. Dust and suspended particles in the environment can easily penetrate the light-transmitting area, contaminating the fiber end face and lens surface, resulting in a significant increase in optical path loss or even failure. Summary of the Invention

[0005] In order to overcome the technical defects of existing adhesive-free fiber array coupler protection structures, this application provides a breathable and dustproof structure for adhesive-free fiber array couplers.

[0006] The adhesive-free fiber array coupler described in this application refers to a coupling structure in which the fiber array unit and the lens array are fixed with epoxy resin around the periphery and the central light-transmitting area is adhesive-free. The central light-transmitting area is the adhesive-free light-transmitting area.

[0007] This application provides a breathable and dustproof structure for a glue-free fiber optic array coupler, employing the following technical solution: It includes a modified ePTFE film strip, a composite adhesive layer, micro-support bumps, and a circumferential hydrophobic protective layer; the modified ePTFE film strip covers the periphery of the junction between the fiber optic array unit and the lens array, and its surface is treated with hydrophobic and oleophobic modification. The modified ePTFE film strip has a submicron-level controllable microporous structure with an average pore size of 0.1μm~0.5μm and a thermal shrinkage rate of <0.1% within a temperature range of -55℃~125℃; the composite adhesive layer is coated on both sides of the modified ePTFE film strip, and is a fluorine coupling agent undercoating and a low-fluorine coupling agent base coating. The composite structure features a low-stress, low-deposition silicone rubber layer. The modified ePTFE film strip is sealed and bonded to the surface of the fiber array unit and lens array via a composite adhesive layer, forming a semi-enclosed protective cavity above the adhesive-free light-transmitting area. The micro-support bumps are distributed in a dot matrix pattern in the non-light-transmitting areas of the fiber array unit and / or lens array body, and are located below the center of the modified ePTFE film strip. A non-contact gap of 2μm to 3μm is left between the micro-support bumps and the modified ePTFE film strip. The circumferential hydrophobic protective layer is coated on the outer peripheral edge of the junction between the fiber array unit and the lens array, and is a nano-hydrophobic coating with a water contact angle ≥110°. The fluorine coupling agent base layer of the composite adhesive layer is combined with the low-stress, low-exudation silicone layer to achieve a firm and sealed bond between the thin film strip and the fiber array unit and lens array body. Combined with the 2μm~3μm non-contact limiting design of the dot matrix micro-support protrusions, it not only improves the vibration resistance of the structure and avoids problems such as adhesive layer cracking, thin film flutter and secondary contamination of microparticles caused by vibration, but also achieves stress-free protection and ensures the long-term stability of the precision coupling accuracy between the fiber array unit and the lens array.

[0008] Optionally, the modified ePTFE film strip is a cross-linked fluoropolymer modified ePTFE film with a thickness of 25μm~50μm, a micropore porosity of 70%~80%, and a tensile strength ≥20MPa, possessing both flexibility and mechanical strength. The width of the modified ePTFE film strip is 3mm~5mm larger than the width of the joint between the fiber array unit and the lens array, and a 0.5mm rounded chamfer is made at the edge of the corresponding optical light transmission area to improve the assembly alignment tolerance and avoid blocking the light path.

[0009] Optionally, the modified ePTFE film tape has an average micropore diameter of 0.2 μm, which is the optimal balance between dust prevention and air permeability. It can completely block typical environmental dust particles with a particle size >1 μm, while providing an efficient diffusion channel for water vapor (dynamic diameter of about 0.0004 μm) and air molecules.

[0010] Optionally, the thickness of the fluorine coupling agent base coating is 0.5μm~1μm, and the thickness of the low-stress, low-exudation silicone layer is 3μm~5μm; the low-stress, low-exudation silicone is an addition-type silicone rubber with a low molecular weight exudation of <0.01% and a Shore hardness of A20~A30, which combines low-stress characteristics with high elasticity, can compensate for deformation under vibration conditions, and does not release harmful substances that pollute the optical surface.

[0011] Optionally, the micro-support bumps are epoxy resin microspheres with a diameter of 10μm~15μm and a dot spacing of 2mm~3mm. The top of the micro-support bumps is flat and the height is consistent with ±0.5μm to ensure uniform positioning of the film strip and avoid local stress concentration.

[0012] Optionally, the circumferential hydrophobic protective layer is a nano-silica hydrophobic coating, which is applied to a 1mm~2mm annular area around the junction of the fiber array unit and the lens array. The coating thickness is <1μm, which does not affect the mechanical fixation and coupling accuracy of the fiber array unit / lens array, and the hydrophobic effect is long-lasting.

[0013] Optionally, the gap between the semi-enclosed protective cavity and the lower optical light transmission area is 8μm~12μm, which ensures efficient diffusion of gas inside the protective cavity to the outside world and avoids condensation, while also avoiding contamination or stress caused by direct contact between the modified ePTFE film strip and the optical surface.

[0014] Optionally, the fiber array unit is a ceramic ferrule structure, the lens array is a glass lens structure, and the non-light-transmitting areas of the fiber array unit and the lens array are fixed by curing with low-stress, high-temperature resistant epoxy resin to form a fixing layer, thereby achieving mechanical fixation between the fiber array unit and the lens array without introducing excessive thermal stress to the optical elements.

[0015] In summary, this application includes the following beneficial technical effects:

[0016] 1. The submicron-level controllable micropores of the modified ePTFE film tape in this invention combine efficient dust prevention with breathability and anti-condensation. The low shrinkage rate under ultra-wide temperature range ensures stable performance in complex temperature change environments from -55℃ to 125℃. Combined with hydrophobic and oleophobic modification and a circumferential nano-hydrophobic protective layer, it can also achieve all-round pollution prevention against water vapor and oil stains, protecting the optical light transmission area from pollution.

[0017] 2. In this invention, the composite adhesive layer of fluorine coupling agent and low-stress, low-exudation silicone achieves a firm and sealed bond between the thin film strip and the fiber array unit and lens array body. The non-contact limiting design of the dot matrix micro-support protrusions not only improves vibration resistance and avoids bonding cracking, film flutter and secondary contamination of microparticles caused by vibration, but also does not introduce mechanical stress into the optical components throughout the process, ensuring the long-term stability of the precision coupling accuracy between the fiber array unit and the lens array. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the connection between the fiber optic array unit and the lens array in an embodiment of this application;

[0020] Figure 3 yes Figure 2 Enlarged structural diagram of section A in the middle;

[0021] Figure 4 This is a schematic diagram of the ePTFE film strip structure in an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the circumferential hydrophobic protective layer in an embodiment of this application;

[0023] Figure 6 yes Figure 5 A magnified structural diagram of section B.

[0024] Reference numerals: 1. ePTFE film strip; 2. Fiber optic array unit; 3. Lens array; 4. Composite adhesive layer; 5. Semi-enclosed protective cavity; 6. Micro-support protrusions; 7. Circumferential hydrophobic protective layer. Detailed Implementation

[0025] The following is in conjunction with the appendix Figures 1-6 This application will be further described in detail below. The technical solutions in the embodiments of this application will be clearly described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0026] This application discloses a breathable and dustproof structure for a glue-free fiber optic array coupler. It is applied to the junction of a fiber optic array unit 2 with a periphery fixed in epoxy resin and a central light-transmitting area free of adhesive, and a lens array 3. The fiber optic array unit 2 uses a ceramic ferrule structure, and the lens array 3 uses a glass lens structure. Both are suitable for the application requirements of 12-core / 24-core / 32-core high-density optical modules. The following uses a 32-core ultra-high-density glue-free fiber optic array coupler as the core embodiment to describe in detail the fabrication, assembly, and mating relationships of the structure.

[0027] Example 1: Assembly of a breathable and dustproof structure for a 32-core glue-free fiber optic array coupler:

[0028] The breathable and dustproof structure of this embodiment includes a modified ePTFE film strip 1, a composite adhesive layer 4, micro-support bumps 6, and a circumferential hydrophobic protective layer 7. The specifications of each component strictly follow the scope defined in the claims. The specific assembly steps are as follows:

[0029] 1. Precision alignment and fixing layer preparation of fiber array unit 2 and lens array 3: The 32-core ceramic ferrule fiber array unit 2 and the 32-core glass lens array 3 are placed on an ultra-precision vision alignment platform. The optical axis is precisely aligned by laser interferometry, and the alignment accuracy is controlled within ±0.3μm. Low-stress, high-temperature resistant epoxy resin is uniformly applied to the non-light-transmitting areas around them using a micro-dispensing process. After coating, the components are placed in a 120℃ oven for 1.5h to heat and cure, forming an epoxy resin fixing layer to achieve mechanical fixation of fiber array unit 2 and lens array 3. After cooling to room temperature, the central optical light-transmitting area remains clean and free of any epoxy resin residue. Subsequently, a plasma cleaning process is used to clean the joint and outer surface of fiber array unit 2 and lens array 3 to remove oil, impurities and oxide layers, ensuring the subsequent bonding and coating effects.

[0030] 2. Preparation of micro-support bumps 6: Epoxy resin microspheres with a diameter of 12 μm were selected and mixed with low-viscosity epoxy curing agent at a mass ratio of 9:1 and stirred thoroughly to obtain a microsphere mixture. The microsphere mixture was dot-matrix coated onto the non-light-transmitting areas of the fiber array unit 2 and lens array 3 (the coating position corresponds to the lower center of the subsequent modified ePTFE film strip 1) using a micro-dispensing process, with the dot spacing controlled at 2.5 mm. After coating, the microsphere mixture was preheated at 80℃ for 30 min and then heated to 100℃ for 1 h to form micro-support bumps 6 of the epoxy resin microsphere cured body.

[0031] The micro-support bumps 6 are flat at the top, with a height uniformity of ±0.5μm and a regular dot matrix distribution. They provide non-contact limiting support for the subsequent modified ePTFE film strip 1, without occupying the optical transmission area or affecting the optical signal transmission.

[0032] 3. Coating of circumferential hydrophobic protective layer 7: Using a nano-spraying process, a nano-silica hydrophobic coating is applied to the outer peripheral edge of the junction between the fiber array unit 2 and the lens array 3. The coating area is a ring-shaped area with a width of 1.5 mm, and the coating thickness is precisely controlled to be 0.8 μm (<1 μm). After coating, the component is placed in a 110℃ hot air oven for 30 min to cure, forming the circumferential hydrophobic protective layer 7.

[0033] 4. Pretreatment of modified ePTFE film strip 1: A cross-linked fluoropolymer modified ePTFE film is selected, with an average micropore diameter of 0.2μm (0.1μm~0.5μm), a thickness of 35μm (25μm~50μm), a micropore porosity of 75% (70%~80%), a tensile strength ≥20MPa, and a thermal shrinkage rate of <0.1% in the temperature range of -55℃~125℃; according to the size of the joint between the fiber array unit 2 and the lens array 3, the modified ePTFE film is cut into a film strip with a width of 6mm (4mm larger than the joint width, within the range of 3mm~5mm), and a 0.5mm rounded chamfer is made on the edge of the corresponding optical light transmission area of ​​the film strip using laser cutting technology to avoid assembly misalignment from blocking the light path;

[0034] The surface of the cut modified ePTFE film strip 1 is subjected to plasma hydrophobic and oleophobic modification treatment to improve its surface hydrophobic and oleophobic properties and prevent liquid water and oil from adhering and clogging the micropores; then, a composite adhesive layer 4 is sequentially coated on the lower surface of the two long sides of the film strip.

[0035] (1) A fluorine coupling agent is coated by vacuum spraying to form a fluorine coupling agent base coating with a thickness of 0.8 μm (within the range of 0.5 μm to 1 μm). After coating, the coating is left to stand for 10 min to allow the coupling agent to fully adsorb and combine with the surface of the film.

[0036] (2) On the surface of the fluorine coupling agent base coating, an addition-type silicone rubber is coated by micro-scraping process to form a low-stress, low-exudation silicone rubber layer with a thickness of 4μm (within the range of 3μm~5μm). The low molecular weight exudation of the addition-type silicone rubber is <0.01%, and the Shore hardness is A25 (within the range of A20~A30). After coating, it is left to stand for 5 minutes to allow the silicone rubber to be in a semi-cured state, which is convenient for subsequent bonding.

[0037] 5. Assembly and Sealing Curing of Modified ePTFE Film Strip 1: The pre-treated modified ePTFE film strip 1 is precisely covered around the junction of the fiber array unit 2 and the lens array 3 using a visual alignment device, completely covering the optical transmission area; three fitting accuracies are ensured during assembly:

[0038] (1) A non-contact gap of 2.5 μm (within the range of 2 μm to 3 μm) is left between the lower middle part of the film strip and the micro support protrusion 6 to achieve non-contact limiting and avoid film strip flutter under vibration;

[0039] (2) A 10μm protective cavity gap (within the range of 8μm~12μm) is left between the thin film strip and the optical light transmission area below, forming a semi-closed protective cavity 5, which ensures gas diffusion efficiency and avoids contamination or stress caused by the contact between the thin film strip and the optical surface.

[0040] (3) The rounded corners of the film strip completely avoid the light-transmitting area and are not obstructed in any way;

[0041] After alignment, a soft silicone pressure head is used to apply a uniform pressure of 0.04 MPa to the composite adhesive layer 4 on both sides of the film strip, and the pressure is maintained for 20 seconds to ensure that the composite adhesive layer 4 is tightly bonded to the body surface of the fiber array unit 2 and the lens array 3. Then, the entire assembly is placed in a 90°C oven and heated for 1.5 hours to allow the composite adhesive layer 4 to fully cure. The modified ePTFE film strip 1 is then sealed and bonded to the body of the fiber array unit 2 and the lens array 3 through the composite adhesive layer 4, finally forming a semi-closed protective cavity 5 with micro-supports, thus completing the assembly of the entire breathable and dustproof structure.

[0042] Example 2: Assembly of a breathable and dustproof structure for a 12-core glue-free fiber optic array coupler:

[0043] This embodiment is designed for applications using a 12-core conventional density optical module. Based on Embodiment 1, the specifications of each component have been adjusted for compatibility, and all adjusted parameters are within the scope defined in the claims.

[0044] 1. The micro-support protrusions 6 are made of epoxy resin microspheres with a diameter of 10μm and a dot spacing of 2mm;

[0045] 2. A circumferential hydrophobic protective layer 7 is coated on a 1mm annular area around the joint, with a coating thickness of 0.5μm and a water contact angle of 112°;

[0046] 3. Modified ePTFE film strip 1: Select a cross-linked fluoropolymer modified ePTFE film with a thickness of 25μm and a porosity of 70%. The average pore size of the micropores is 0.1μm. The width of the film strip is 3mm larger than the joint seam, and the rounded chamfer is still 0.5mm.

[0047] 4. In the composite adhesive layer 4, the thickness of the fluorine coupling agent base layer is 0.5μm, the thickness of the low-stress, low-exudation silicone layer is 3μm, and the Shore hardness of the addition-type silicone rubber is A20.

[0048] 5. Assembly gap: The non-contact gap between the micro-support protrusion 6 and the film strip is 2μm, and the gap between the film strip and the protective cavity of the optical transmission area is 8μm.

[0049] The assembly steps in this embodiment are the same as in Embodiment 1. The resulting breathable and dustproof structure can meet the dustproof, breathable, anti-condensation and vibration resistance requirements of a 12-core conventional density glue-free fiber array coupler, and is suitable for the application scenarios of industrial-grade conventional optical modules.

[0050] Example 3: Assembly of a breathable and dustproof structure for a 24-core glue-free fiber optic array coupler:

[0051] This embodiment is adapted to a 24-core medium-density optical module, and the component specifications are adjusted as follows (all within the scope of the claims):

[0052] 1. The micro-support protrusions 6 are made of epoxy resin microspheres with a diameter of 15μm and a dot spacing of 3mm;

[0053] 2. A circumferential hydrophobic protective layer 7 is applied to a 2mm annular area around the joint, with a coating thickness of 0.9μm and a water contact angle of 118°.

[0054] 3. Modified ePTFE film strip 1: Select a cross-linked fluoropolymer modified ePTFE film with a thickness of 50μm and a porosity of 80%, with an average micropore diameter of 0.5μm, a film strip width that is 5mm larger than the joint seam, and a rounded chamfer of 0.5mm;

[0055] 4. In the composite adhesive layer 4, the thickness of the fluorine coupling agent base layer is 1μm, the thickness of the low-stress, low-exudation silicone layer is 5μm, and the Shore hardness of the addition-type silicone rubber is A30.

[0056] 5. Assembly gap: The non-contact gap between the micro-support protrusion 6 and the film strip is 3μm, and the gap between the film strip and the protective cavity of the optical transmission area is 12μm.

[0057] The assembly steps in this embodiment are the same as in Embodiment 1. The resulting structure takes into account both the miniaturization and protection reliability requirements of medium-density optical modules, and is suitable for the application scenarios of outdoor wide-temperature optical devices.

[0058] In the breathable and dustproof structure of this application, the modified ePTFE film strip 1, the composite adhesive layer 4, the micro-support protrusions 6, and the circumferential hydrophobic protective layer 7 form a synergistic integrated structure. The interaction of these components achieves multiple functions, including efficient dustproofing, active breathability and anti-condensation, resistance to mechanical vibration, prevention of capillary water penetration, and stress-free protection. The core implementation principle is as follows:

[0059] 1. Modified ePTFE film with strip 1 as the core functional layer has submicron-level controllable micropores of 0.1μm~0.5μm, which can completely block environmental dust particles with a particle size >1μm, while providing efficient diffusion channels for water vapor and air molecules, achieving a balance between dust prevention and breathability and anti-condensation; cross-linked fluoropolymer modification and hydrophobic and oleophobic modification treatment ensure that its microporous structure is stable in an ultra-wide temperature environment of -55℃~125℃, without performance degradation caused by thermal shrinkage / expansion, and is not easily blocked by liquid water and oil;

[0060] 2. The composite adhesive layer 4 is a composite structure of a fluorine coupling agent base layer and a low-stress, low-exudation silicone rubber layer. The fluorine coupling agent enables chemical bonding between the modified ePTFE film strip 1 and the fiber array unit 2 / lens array 3 body, improving the adhesion. The low-stress addition-type silicone rubber layer has high elasticity and can compensate for deformation under vibration conditions, avoiding cracking of the adhesive layer. Moreover, the amount of low molecular weight exudation is extremely low, and it will not cause secondary contamination of the optical surface.

[0061] 3. The dot matrix micro-support protrusions 6 provide non-contact limiting for the modified ePTFE film strip 1, limiting the flutter amplitude of the film strip under vibration, fundamentally solving the problems of fatigue cracking of the adhesive layer and secondary contamination of microparticles caused by flutter, and the 2μm~3μm non-contact gap ensures that no mechanical stress is transmitted to the optical element.

[0062] 4. The circumferential hydrophobic protective layer 7 increases the water contact angle on the surface of the fiber array unit 2 / lens array 3, blocking the capillary penetration path of liquid water, thus making up for the shortcomings of traditional structures that only protect the joint seam and not the outer periphery, and achieving all-round pollution prevention.

[0063] 5. The modified ePTFE film strip 1 and the 8μm~12μm protective cavity gap between the optical light transmission area and the protective cavity, as well as the rounded corners and widened design, not only ensure the efficient exchange of gas between the semi-enclosed protective cavity 5 and the outside world, but also improve the assembly alignment tolerance and avoid blocking the light path. At the same time, all components do not directly contact the optical light transmission surface, achieving stress-free protection and ensuring the long-term stability of the coupling accuracy between the fiber array unit 2 and the lens array 3.

[0064] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A dustproof structure of a glue-free optical fiber array coupler, applied to a joint part of an optical fiber array unit (2) and a lens array (3), wherein the optical fiber array unit (2) and the lens array (3) are fixed by a peripheral epoxy resin and a central glue-free light transmission area, and the central glue-free light transmission area is a glue-free light transmission area, characterized in that, It includes a modified ePTFE film strip (1), a composite adhesive layer (4), micro-support bumps (6) and a circumferential hydrophobic protective layer (7). The modified ePTFE film strip (1) covers the periphery of the junction between the fiber array unit (2) and the lens array (3). Its surface is treated with hydrophobic and oleophobic modification. The modified ePTFE film strip (1) has a submicron-level controllable microporous structure with an average pore size of 0.1μm~0.5μm and a thermal shrinkage rate of <0.1% in the temperature range of -55℃~125℃. The composite adhesive layer (4) is coated on both sides of the modified ePTFE film strip (1), and is a composite structure of fluorine coupling agent base layer and low stress low precipitation silicone layer. The modified ePTFE film strip (1) is sealed and bonded to the body surface of fiber array unit (2) and lens array (3) through the composite adhesive layer (4), forming a semi-closed protective cavity (5) above the glue-free light-transmitting area. The micro-support bumps (6) are distributed in a dot matrix pattern in the non-light-transmitting area of ​​the fiber array unit (2) and / or lens array (3) body, and are located below the middle of the modified ePTFE film strip (1). A non-contact gap of 2μm~3μm is left between the micro-support bumps (6) and the modified ePTFE film strip (1). The circumferential hydrophobic protective layer (7) is coated on the outer peripheral edge of the junction of the fiber array unit (2) and the lens array (3), and is a nano-hydrophobic coating with a water contact angle ≥110°.

2. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The modified ePTFE film strip (1) is a cross-linked fluoropolymer modified ePTFE film with a thickness of 25μm~50μm, a micropore porosity of 70%~80%, and a tensile strength ≥20MPa. The width of the modified ePTFE film strip (1) is 3mm~5mm larger than the width of the joint between the fiber array unit (2) and the lens array (3), and a 0.5mm rounded chamfer is made at the edge of the corresponding optical light transmission area.

3. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The modified ePTFE film tape (1) has an average pore size of 0.2 μm.

4. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The thickness of the fluorine coupling agent base coating is 0.5μm~1μm, and the thickness of the low-stress, low-exudation silicone layer is 3μm~5μm; the low-stress, low-exudation silicone is addition-type silicone rubber with a low molecular weight exudate content of <0.01% and a Shore hardness of A20~A30.

5. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The micro-support bumps (6) are epoxy resin microspheres with a diameter of 10μm~15μm and a dot spacing of 2mm~3mm. The top of the micro-support bumps (6) is flat and the height is consistent with ±0.5μm.

6. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The circumferential hydrophobic protective layer (7) is a nano-silica hydrophobic coating, which is coated on the annular area of ​​1mm~2mm around the junction of the fiber array unit (2) and the lens array (3), with a coating thickness of <1μm.

7. The breathable and dustproof structure of a glue-free fiber optic array coupler according to claim 1, characterized in that: The gap between the semi-enclosed protective cavity (5) and the optical light-transmitting area below is 8μm~12μm.

8. The breathable and dustproof structure of the glue-free fiber array coupler according to any one of claims 1-7, characterized in that, The fiber array unit (2) is a ceramic ferrule structure, the lens array (3) is a glass lens structure, and the non-light-transmitting areas of the fiber array unit (2) and the lens array (3) are fixed by curing with low-stress, high-temperature resistant epoxy resin.

Images