Capillary tube with fiber and capillary tube fiber penetrating and dispensing process

Abstract

The invention discloses a capillary tube with a fiber and a capillary tube fiber penetrating dispensing technology, and the capillary tube comprises a capillary tube which is provided with an insertion port and a connection cavity communicated with the insertion port, and is used for the insertion of an optical fiber; the peripheral side of the optical fiber is connected with a rubber bead, the rubber bead is used for abutting against the insertion opening when the optical fiber is inserted into the connecting cavity, the space between the inner side of the rubber bead and the insertion opening is filled with a hard rubber layer, the hard rubber layer is used for tightly holding the optical fiber, and the outer side of the rubber bead is connected through a soft rubber layer. And the rubber beads are blocked between the hard rubber layer and the soft rubber layer.

Description

Technical Field

[0001] This invention relates to the field of capillary fiber-threading and dispensing technology, and more particularly to a fiber-embedded capillary and a capillary fiber-threading and dispensing process. Background Technology

[0002] In data center optical modules, optical fibers need to transmit light, requiring capillaries as carriers. The optical fibers are fixed inside the capillaries with adhesive. The conventional process is to first apply a high-hardness adhesive with a high expansion coefficient to fix the optical fiber inside the capillary flare, and then apply a low-hardness adhesive with a low expansion coefficient to the outside of the flare to protect and buffer the optical fiber. The two adhesives are then baked and cured separately. Before the product is delivered to the customer, a rapid TC screening test (-40~85℃, 10℃ / min) is required.

[0003] Because the expansion coefficients of the two adhesives differ significantly, the expansion and contraction forces exerted by the two adhesives on the optical fiber are inconsistent during the TC test. At the junction of the two adhesives, the optical fiber often develops ring cracks, resulting in low yield and unacceptable reliability of the finished product.

[0004] Therefore, a fiber-embedded capillary and capillary fiber-insertion dispensing process is still needed to solve the above problems. Summary of the Invention

[0005] This invention provides a fiber-supported capillary and a process for fiber-threading and dispensing of the capillary to solve the above problems.

[0006] The objective of this invention is achieved through the following technical solution: The first aspect of this invention discloses a capillary tube, comprising: A capillary tube having an insertion port and a connecting cavity communicating with the insertion port for inserting an optical fiber; An optical fiber has adhesive beads attached to its periphery. The adhesive beads are used to abut against the insertion port when the optical fiber is inserted into the connection cavity. A hard adhesive layer is filled between the inner side of the adhesive beads and the insertion port. The hard adhesive layer is used to hold the optical fiber tightly. The outer side of the adhesive beads is connected by a soft adhesive layer, and the adhesive beads are blocked between the hard adhesive layer and the soft adhesive layer.

[0007] Preferably, the coefficient of thermal expansion of the adhesive bead is between that of the hard adhesive layer and the soft adhesive layer.

[0008] Preferably, the adhesive bead is spherical, and the spherical outline of the adhesive bead is tangent to the insertion port; The insertion port is funnel-shaped along the axial direction of the capillary.

[0009] Preferably, the soft adhesive layer covers the optical fiber between the insertion port and the periphery of the optical fiber, and the diameter of the soft adhesive layer decreases along the axial direction of the capillary.

[0010] Preferably, the outer periphery of the optical fiber is further coated with a coating, the part of the optical fiber inserted into the connection cavity is the stripping part, and the distance between the stripping opening of the optical fiber and the edge of the adhesive bead is 1-2 mm.

[0011] Preferably, half of the volume of the adhesive bead is located inside the insertion port, and the other half is located inside the soft adhesive layer outside the insertion port.

[0012] Another aspect of the present invention provides a capillary fiber-threading dispensing process, comprising: Spherical adhesive with a neutral coefficient of thermal expansion is applied to the periphery of the optical fiber and cured into adhesive beads. Apply high-expansion-coefficient glue to the inside of the capillary tube; The optical fiber is inserted into the insertion port of the capillary tube and then cured after contact with the glue in the insertion port to form a hard glue layer and glue beads connected to the hard glue layer. Apply low-expansion-coefficient adhesive to the insertion port and the glue bead outside the flared mouth, so that the adhesive covers the remaining glue bead portion and covers the insertion port to cure and form a soft adhesive layer.

[0013] Preferably, the coefficient of thermal expansion of the hard adhesive layer is 180-220, and the hardness is 80-120. The glue beads have a glue expansion coefficient of 120-160 and a hardness of 50-75. The adhesive expansion coefficient of the soft adhesive layer is 80-115, and the hardness is 30-50.

[0014] Preferably, the curing step of the adhesive with a neutral coefficient of thermal expansion includes curing for 50-70 seconds using a UV light source.

[0015] Preferably, the step of inserting the optical fiber into the insertion port of the capillary and curing it after contact with the adhesive in the insertion port includes: Bake at room temperature up to 50℃ for 2 hours, then up to 85℃ for 5 hours, then up to 110℃ for 3 hours, then down to 50℃ for 1 hour, and finally back to room temperature. The process of coating the remaining glue bead with glue and covering the insertion port to cure and form a soft glue layer includes: Bake at room temperature to 85℃ for 9 hours, then at 110℃ for 2 hours, and finally cool to room temperature.

[0016] Compared with the prior art, the beneficial effects of the present invention include at least the following: By connecting adhesive beads around the periphery of the optical fiber, the optical fiber with adhesive beads is inserted after filling with hard adhesive and then cured. The hard adhesive serves to fix the optical fiber and the inner wall of the capillary. Finally, soft adhesive is wrapped around the outer part of the optical fiber and the adhesive beads. The soft adhesive protects the outside of the optical fiber and the connection point of the capillary. The adhesive beads act as a barrier between the hard adhesive and the soft adhesive. In the TC screening test of the product, the adhesive beads can play a transition role, providing both a certain rigidity and sufficient flexibility, so that the optical fiber between the hard adhesive and the adhesive beads, as well as the optical fiber between the soft adhesive and the adhesive beads, will not experience ring cracking. Attached Figure Description

[0017] Figure 1 These are traditional optical fiber and capillary structures in the background technology; Figure 2 This is the optical fiber and capillary structure of an embodiment of the present invention; Figure 3 These are the dispensing process steps in an embodiment of the present invention.

[0018] 1. Capillary tube; 2. Insertion port; 3. Optical fiber; 4. Hard adhesive layer; 5. Soft adhesive layer; 6. Adhesive beads. Detailed Implementation

[0019] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0020] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0021] This invention provides a capillary tube 1, comprising: The capillary tube 1 has an insertion port 2 and a connecting cavity communicating with the insertion port 2 for inserting an optical fiber 3. The capillary tube 1 serves as a carrier for the optical fiber 3, assisting in its insertion into the interface of a pre-designed optical device during insertion.

[0022] An optical fiber 3 has adhesive beads 6 connected to its periphery. The adhesive beads 6 are used to abut against the insertion port 2 when the optical fiber 3 is inserted into the connection cavity. A hard adhesive layer 4 is filled between the inner side of the adhesive beads 6 and the insertion port 2. The hard adhesive layer 4 is used to hold the optical fiber 3 tightly. The outer side of the adhesive beads 6 is connected by a soft adhesive layer 5. The adhesive beads 6 are separated between the hard adhesive layer 4 and the soft adhesive layer 5. The adhesive beads 6 are injected into the periphery of the optical fiber 3 by a dispensing machine or manual dispensing, making it spherical and then curing it. Then, the optical fiber 3 with adhesive beads 6 is inserted into the insertion port 2, so that the inner side of the adhesive beads 6 and the hard adhesive in the insertion port 2 are filled, and the outer side is covered by soft adhesive. When temperature changes cause stress, the hard adhesive in the insertion port 2 generates a pulling force towards the connection cavity. The adhesive beads 6 block the pulling force on both sides of the transition between the hard adhesive and the soft adhesive, avoiding excessive stress concentration in the hard adhesive. The spherical adhesive beads 6 can stably disperse the stress generated by the hard adhesive and avoid the pulling force generated by the capillary 1.

[0023] Preferably, the coefficient of thermal expansion of the adhesive bead 6 is between that of the hard adhesive layer 4 and the soft adhesive layer 5. Among the adhesive beads 6, the hard adhesive layer 4 has the largest coefficient of thermal expansion, followed by the adhesive bead 6, and the soft adhesive layer 5 has the smallest coefficient of thermal expansion. When the temperature changes, the adhesive bead 6, as a material between the two, can adequately transition the stress between the hard and soft adhesives, preventing excessive deformation due to tensile force on one side, which could cause the optical fiber 3 to break along the axial direction.

[0024] Preferably, the adhesive bead 6 is spherical, and the spherical outline of the adhesive bead 6 is tangent to the insertion port 2. The spherical outline of the adhesive bead 6 is preferably tangent to the insertion port 2. This ensures that when the hard adhesive is fully filled in the insertion port 2, it does not easily overflow, completely blocking the hard adhesive at the insertion port 2 and maintaining sufficient clamping force to hold the hard adhesive tightly around the insertion port 2 and the periphery of the optical fiber 3.

[0025] The insertion port 2 is funnel-shaped along the axial direction of the capillary tube 1. The type of inner generatrix curve of the funnel shape is not limited.

[0026] Preferably, the flexible adhesive layer 5 covers the optical fiber 3 between the insertion port 2 and the periphery of the optical fiber 3, and the diameter of the flexible adhesive layer 5 decreases along the axial direction of the capillary 1. Specifically, along the axial direction from the insertion port 2 to the side away from the insertion port 2, the outer edge of the flexible adhesive layer 5 gradually tapers with a smooth curve, and this gradually decreasing tapered design provides a smooth transition in stiffness. It distributes the stress applied to the optical fiber 3 gradually and evenly from the most rigid part of the capillary 1 along the tapered region to the more flexible optical fiber 3 itself. This avoids abrupt changes in stress and greatly reduces stress concentration, thus improving the product's service life.

[0027] Preferably, the outer periphery of the optical fiber 3 is further coated with a coating. The portion of the optical fiber 3 inserted into the connection cavity is a stripped portion, and the distance between the stripped opening of the optical fiber 3 and the edge of the adhesive bead 6 is 1-2 mm. For example, the optical fiber 3 is coated with an acrylic material. When inserted into the insertion port 2, part of the coating on the surface of the optical fiber 3 is removed through a stripping process before being inserted into the capillary tube 1. At this time, it is necessary to ensure that the edge of the adhesive bead 6 and the cut surface of the stripped opening are spaced 1-2 mm apart to avoid the interface between the adhesive bead 6 and the hard adhesive coinciding with the cut surface of the stripped opening. This would cause the coating of the optical fiber 3 to break first, resulting in an unstable point of contact for the adhesive bead 6 and reduced stress buffering on the soft adhesive.

[0028] In one embodiment, half the volume of the adhesive bead 6 is located inside the insertion port 2, and the other half is located inside the soft adhesive layer 5 outside the insertion port 2. When half the volume of the adhesive bead 6 is inserted into the insertion port 2, and the other part is located inside the soft adhesive layer 5, the arc-shaped contour of the adhesive bead 6 is evenly distributed on the inner and outer sides of the insertion port 2, making uniform contact with the soft and hard adhesives respectively. When the hard adhesive generates a large tensile force, the adhesive bead 6 can evenly transfer the stress to the soft adhesive side, avoiding stress concentration from direct contact between the hard and soft adhesives, which could cause the optical fiber 3 to be pulled apart axially.

[0029] In another aspect, the present invention discloses a capillary fiber-threading dispensing process, comprising: A spherical adhesive with a neutral coefficient of thermal expansion is applied to the periphery of the optical fiber 3 and cured into an adhesive bead 6. The adhesive bead 6 is preferably spherical, forming an elliptical sphere that is thinner at both ends and thicker in the middle, which also achieves the effect of this patent. During application, adhesive can be applied manually or by a robotic arm to the axis of the optical fiber 3, and then cured into an adhesive bead 6.

[0030] Apply a high-expansion-coefficient adhesive to the insertion port 2 of capillary tube 1. Inject the high-expansion-coefficient adhesive into the inlet of the insertion port 2 of capillary tube 1, either manually or automatically.

[0031] An optical fiber 3 is inserted into the insertion port 2 of the capillary 1, and after contact with the adhesive in the insertion port 2, it is cured to form a hard adhesive layer 4 and adhesive beads 6 connected to the hard adhesive layer 4. An optical fiber 3 with adhesive beads 6 is inserted into the capillary 1 and contacted with the injected adhesive with a high coefficient of expansion, and then cured to form two sections with different hardness.

[0032] Apply a low-expansion-coefficient adhesive to the insertion port 2 and the adhesive bead 6 outside the flared end. The adhesive coats the remaining portion of the adhesive bead 6 and covers the insertion port 2, curing to form a soft adhesive layer 5. Adhesive beads 6 form between the soft and hard adhesive layers. When the product undergoes a TC screening test, the hard adhesive will generate significant axial stress, pushing outwards from the insertion port 2. The adhesive beads 6, with their moderate hardness, moderate expansion coefficient, and spherical shape, effectively prevent the stress from spreading further and offsets it, avoiding excessive stress difference between the soft and hard adhesive layers and preventing it from concentrating at the cross-linking point, which could lead to the fiber optic cable 3 breaking.

[0033] Preferably, the coefficient of thermal expansion of the hard adhesive layer 4 is 180-220, and the hardness is 80-120. The glue bead 6 has a glue expansion coefficient of 120-160 and a hardness of 50-75; The adhesive expansion coefficient of the soft adhesive layer 5 is 80-115, and its hardness is 30-50. Experimental results show that under this combination, the hard adhesive layer 4 and the soft adhesive layer 5 can maintain a good connection while avoiding stress concentration between them, which could lead to breakage.

[0034] In one embodiment, the curing step of the adhesive with a neutral coefficient of thermal expansion includes curing for 50-70 seconds using a UV light source. The adhesive with a neutral coefficient of thermal expansion is a UV-curable material. During curing, the 50-70 seconds of UV light curing causes a cured film to form on the outer edge of the spherical adhesive bead 6 in contact with air, while the adhesive inside the film remains fluid. The resulting light-cured adhesive bead 6 is relatively soft, and when inserted into the insertion port 2, it maintains a good filling shape, making full contact with the inner wall of the insertion port 2 at multiple points. This effectively prevents the hard adhesive from filling empty spaces or overflowing. This allows for the full utilization of subsequent stress resistance properties.

[0035] See also Figure 2 It should be added that when the glue bead 6 is inserted into the flowing hard glue and fills the insertion port 2, it is necessary to control the hard glue to flow along the arc contour at this time, and to prevent the hard glue from flowing past the highest point of the arc of the glue bead 6. This can fully maintain the filling effect of the hard glue, and on the other hand, it can also prevent the hard glue from flowing past the highest point of the glue bead 6 and onto the optical fiber 3 on the other side of the insertion port, causing greater damage.

[0036] Furthermore, the step of inserting the optical fiber 3 into the insertion port 2 of the capillary 1 and curing it after contact with the adhesive in the insertion port 2 includes: Bake at room temperature up to 50℃ for 2 hours, then up to 85℃ for 5 hours, then up to 110℃ for 3 hours, then down to 50℃ for 1 hour, and finally back to room temperature.

[0037] The process of coating the remaining glue bead with glue and covering the insertion port to cure and form a soft glue layer includes: The adhesive was baked at 85℃ for 9 hours, then at 110℃ for 2 hours, and finally cooled to room temperature. This stepped temperature baking method removed the stress generated by the curing of the hard adhesive and adhesive beads 6, minimizing curing shrinkage stress and thermal shrinkage stress, thereby significantly improving the reliability and lifespan of the adhesive joint under thermal cycling conditions. This ensured that the stress in the materials was largely released during subsequent testing, preventing significant deformation and guaranteeing good clamping force on the optical fiber 3 and capillary 1 during use.

[0038] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A device with capillary fibers, characterized in that, include: A capillary tube having an insertion port and a connecting cavity communicating with the insertion port for inserting an optical fiber; An optical fiber has adhesive beads attached to its periphery. The adhesive beads are used to abut against the insertion port when the optical fiber is inserted into the connection cavity. A hard adhesive layer is filled between the inner side of the adhesive beads and the insertion port. The hard adhesive layer is used to hold the optical fiber tightly. The outer side of the adhesive beads is connected by a soft adhesive layer, and the adhesive beads are blocked between the hard adhesive layer and the soft adhesive layer.

2. The capillary tube according to claim 1, characterized in that, The coefficient of expansion of the adhesive beads is between that of the hard adhesive layer and the soft adhesive layer.

3. The capillary tube according to claim 1, characterized in that, The glue bead is spherical, and the spherical outline of the glue bead is tangent to the insertion port; The insertion port is funnel-shaped along the axial direction of the capillary.

4. The capillary tube according to claim 1, characterized in that, The soft adhesive layer covers the optical fiber between the insertion port and the periphery of the optical fiber, and the diameter of the soft adhesive layer decreases along the axial direction of the capillary.

5. The capillary tube according to claim 4, characterized in that, The outer periphery of the optical fiber is also coated with a coating. The part of the optical fiber inserted into the connection cavity is the stripping part. The distance between the stripping opening of the optical fiber and the edge of the adhesive bead is 1-2 mm.

6. The capillary tube according to claim 5, characterized in that, Half of the volume of the adhesive bead is located inside the insertion port, and the other half is located inside the soft adhesive layer outside the insertion port.

7. A capillary fiber-threading dispensing process, characterized in that, include: Spherical adhesive with a neutral coefficient of thermal expansion is applied to the periphery of the optical fiber and cured into adhesive beads. Apply high-expansion-coefficient glue to the inside of the capillary tube; The optical fiber is inserted into the insertion port of the capillary tube and then cured after contact with the glue in the insertion port to form a hard glue layer and glue beads connected to the hard glue layer. Apply low-expansion-coefficient adhesive to the insertion port and the glue bead outside the flared mouth, so that the adhesive covers the remaining glue bead and the insertion port, and cures to form a soft adhesive layer.

8. The capillary fiber-threading and dispensing process according to claim 7, characterized in that, The coefficient of thermal expansion of the hard adhesive layer is 180-220, and the hardness is 80-120. The glue beads have a glue expansion coefficient of 120-160 and a hardness of 50-75. The adhesive expansion coefficient of the soft adhesive layer is 80-115, and the hardness is 30-50.

9. The capillary fiber-threading and dispensing process according to claim 7, characterized in that, The curing step of the adhesive with a neutral coefficient of thermal expansion includes curing for 50-70 seconds using a UV light source.

10. The capillary fiber-threading and dispensing process according to claim 7, characterized in that, The step of inserting the optical fiber into the insertion port of the capillary and curing it after contact with the adhesive in the insertion port includes: Bake at room temperature up to 50℃ for 2 hours, then up to 85℃ for 5 hours, then up to 110℃ for 3 hours, then down to 50℃ for 1 hour, and finally back to room temperature. The process of coating the remaining glue bead with glue and covering the insertion port to cure and form a soft glue layer includes: Bake at room temperature to 85℃ for 9 hours, then at 110℃ for 2 hours, and finally cool to room temperature.

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