An immersion liquid-cooled light module

Abstract

This invention relates to the field of optical communication technology and provides an immersion liquid-cooled optical module, including a PCB board, a coupling component, and a chip disposed on the PCB board. The chip and the coupling component have a coupled optical path. The module also includes an adhesive block for wrapping the coupled optical path, with the edge of the adhesive block extending to the coupling component and the chip. The adhesive block is a refractive index matching adhesive block made of a fluorine-based material. A method for manufacturing the immersion liquid-cooled optical module is also provided. This invention uses refractive index matching adhesive to wrap the coupled optical path, extending the edge of the adhesive to the coupling component and the chip. A potting process is directly used to form the refractive index matching adhesive block to protect the optical path. Compared to the less adhesive used in existing technologies, a thicker adhesive block can be selected as needed to delay the intrusion of coolant. Furthermore, the use of a fluorine-based material for the adhesive block provides better compatibility with fluorinated coolants and makes it less susceptible to intrusion by fluorinated coolants, greatly extending the service life of the optical module.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to an immersion liquid-cooled optical module. Background Technology

[0002] Immersion liquid-cooled optical modules typically immerse the entire module in a fluorinated coolant. Utilizing the high thermal conductivity (e.g., 0.06 W / (m·K)) of the fluorinated coolant, its chemical inertness, and electrical insulation, it quickly absorbs and removes the heat generated by the module. Compared to traditional air-cooled optical modules, this improves heat dissipation efficiency, thereby enhancing the module's operational stability. However, because the module is immersed in coolant, there is a risk of the fluorinated coolant entering the module and corroding the optical path.

[0003] In existing technologies, optical paths are typically protected by plastic encapsulation or bonding a protective cover to the PCB board to prevent fluorinated coolant from seeping into the optical path, causing refractive index mismatch and increasing optical loss. However, both of these solutions have limitations on the lifespan of the optical module. For example, when using plastic encapsulation to create a seal for the optical path, the fluorinated coolant will slowly permeate the plastic protective shell due to long-term immersion in the plastic, and will also gradually seep into the protective shell from the interface between the plastic shell and the PCB board. Once the fluorinated coolant flows into the optical path, it will cause optical path contamination. Furthermore, while bonding a protective cover to the PCB board can use a metal protective cover to prevent fluorinated coolant from seeping in, the gaps between the metal protective cover and the PCB board can become entry points for fluorinated coolant corrosion. Because the gaps are small, the amount of sealant applied is limited, and as the optical module is used, fluorinated coolant will gradually seep into the metal protective cover and contaminate the optical path. Summary of the Invention

[0004] The purpose of this invention is to provide an immersion liquid-cooled optical module, which can at least solve some of the defects in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an immersion liquid-cooled optical module, comprising a PCB board, a coupling component, and a chip disposed on the PCB board, wherein the chip and the coupling component have a coupling optical path, and further comprising an adhesive block for wrapping the coupling optical path, wherein the edge of the adhesive block extends to the coupling component and the chip, and the adhesive block is a refractive index matching adhesive block made of fluorine-based material.

[0006] Furthermore, it also includes a protective shell for shaping the adhesive block, the protective shell having an opening for injecting refractive index matching adhesive.

[0007] Furthermore, the protective shell is mounted on the PCB board by one or more of the following methods: snap-fit, adhesive, and welding. When adhesive is used, the adhesive is made of the same material as the adhesive block with the same refractive index.

[0008] Furthermore, the protective shell is provided with a positioning groove, which communicates with the opening and has the same size as the rubber block.

[0009] Furthermore, the positioning groove and the opening are connected by a guide channel.

[0010] Furthermore, the protective shell is a plastic shell or a metal shell.

[0011] Furthermore, the coupling component includes an optical fiber array or a coupling lens.

[0012] This invention provides another technical solution: a method for manufacturing an immersion liquid-cooled optical module, comprising the following steps:

[0013] S1, Set up coupling components and chips on the PCB board, and complete the coupling between the coupling components and chips;

[0014] S2 uses fluorine-based materials to make refractive index matching adhesive;

[0015] S3, the prepared refractive index matching adhesive is potted into the coupling optical path between the coupling component and the chip;

[0016] S4. After the refractive index matching adhesive has solidified into a block, the subsequent fabrication of the optical module can be completed.

[0017] Furthermore, the materials used to make the refractive index matching adhesive include a fluorinated acrylate resin matrix, a UV initiator, a perfluoropolyether diluent, and a fluorinated silane coupling agent.

[0018] Furthermore, when potting the refractive index matching adhesive, a protective shell is used to guide and shape the refractive index matching adhesive.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The optical path is wrapped with refractive index matching adhesive, and the edge of the refractive index matching adhesive is extended to the coupling components and chips. The refractive index matching adhesive block is directly formed by potting process to protect the optical path. Compared with the less adhesive in the existing technology, a thicker adhesive block can be selected as needed to delay the intrusion of coolant. At the same time, the adhesive block is made of fluorine-based material, which can have better compatibility with fluorinated coolant and is less likely to be intruded by fluorinated coolant, which greatly improves the service life of the optical module.

[0021] 2. The use of a protective shell facilitates the setting of the adhesive, preventing it from flowing and causing insufficient thickness, thus simplifying the manufacturing process. On the other hand, it forms a physical protection layer on the outside of the adhesive block and also provides some protection against the fluorinated coolant.

[0022] 3. The positioning groove is designed inside the protective shell, which can position the glue in the most suitable position and avoid wasting excess glue. The refractive index matching glue made of fluorine-based materials is expensive, and reducing the use of glue can greatly reduce the production cost. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the PCB board and coupling components of an immersion liquid-cooled optical module provided in an embodiment of the present invention;

[0024] Figure 2 In order to be in Figure 1 Based on this, a structural diagram of the protective shell and the rubber block inside the protective shell was set up;

[0025] Figure 3 for Figure 2 The protective shell is moved upwards to show a schematic diagram of the structure of the rubber block;

[0026] In the attached diagram, the labels are: 1-PCB board; 2-fiber optic array; 3-chip; 4-adhesive block; 5-protective shell; 6-opening; 7-slot. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1 , Figure 2 and Figure 3This invention provides an immersion liquid-cooled optical module, including a PCB board 1, a coupling component, and a chip 3 disposed on the PCB board 1. The chip 3 and the coupling component have a coupled optical path. The optical module also includes an adhesive block 4 for wrapping the coupled optical path. The edge of the adhesive block 4 extends to the coupling component and the chip 3. The adhesive block 4 is a refractive index matching adhesive block made of a fluorine-based material. In this embodiment, a refractive index matching adhesive is used to wrap the coupled optical path, and the edge of the refractive index matching adhesive extends to the coupling component and the chip 3. A refractive index matching adhesive block is directly formed using a potting process to protect the optical path. Compared to the less adhesive used in the prior art, a thicker adhesive block 4 can be selected as needed to delay the intrusion of coolant. Furthermore, using a fluorine-based material for the adhesive block 4 provides better compatibility with fluorinated coolants and makes it less susceptible to intrusion by fluorinated coolants, greatly improving the service life of the optical module. Specifically, the adhesive block 4 in this embodiment is made of a fluorine-based material, which has strong compatibility with fluorinated coolant, giving it extremely strong resistance to fluorinated coolant. In accelerated aging tests, after immersing the optical module in FC-72 for 1000 hours, the light transmittance is >95% and the volume swelling rate is <0.5%, which is much longer than the service life of existing plastic encapsulation and metal shield solutions. Even if existing plastic encapsulation and metal shield solutions use the adhesive made of the fluorine-based material of this embodiment to bond the plastic shell to the PCB, or use the adhesive made of the fluorine-based material of this embodiment to bond the metal shield to the PCB, the gap between the plastic shell and the PCB is small, and the gap between the metal shield and the PCB is also small, so not much adhesive is needed. The blocking effect against fluorinated coolant is completely inferior to that of the adhesive block 4 in this embodiment. The shape of the adhesive block 4 can be made into a cube as shown in the attached figure, or it can be a semi-cylindrical block. The position where the adhesive extends to the coupling component and the chip 3 can also be selected as needed. The uncured adhesive has good ductility, and this characteristic can be used to control the extension position.

[0029] Please see Figure 1 , Figure 2 and Figure 3The optical module also includes a protective shell 5 for shaping the adhesive block 4. The protective shell 5 has an opening 6 for injecting refractive index matching adhesive. In this embodiment, the protective shell 5 facilitates adhesive shaping, prevents adhesive flow that could result in insufficient thickness, and simplifies the manufacturing process. Furthermore, it forms a physical protective layer on the adhesive block 4, providing some protection against the fluorinated coolant. The protective shell 5 has an opening 6; during manufacturing, the refractive index matching adhesive is injected by aligning the pillow with the opening 6. The adhesive flows into the protective shell 5 and solidifies under its protection. The solidified adhesive block 4 and the protective shell 5 together prevent the fluorinated coolant from penetrating. Simultaneously, the flowing adhesive can also flow into the gap between the protective shell 5 and the PCB board 1, improving the connection strength between them.

[0030] Please see Figure 1 , Figure 2 and Figure 3 The protective shell 5 has a positioning groove that communicates with the opening 6, and the positioning groove is the same size as the adhesive block 4. In this embodiment, a positioning groove can be designed in the protective shell 5. By controlling the amount of adhesive injected, the adhesive is formed into an adhesive block 4 only in the positioning groove. The positioning groove and the size of the adhesive block 4 are consistent with each other and the position set in the optical path. Therefore, there is no need to worry about the flowing adhesive flowing away during manufacturing. In addition, the adhesive used in this embodiment is expensive. The positioning groove can avoid wasting adhesive. The appropriate thickness of the adhesive block 4 can be obtained by pre-designing a positioning groove of appropriate size, without causing any waste. At the same time, since a positioning groove is designed in the protective shell 5, the positioning groove will also contact the PCB board 1. After the adhesive solidifies, it increases the bonding surface between the PCB board 1 and the protective shell 5, further improving the connection strength between the protective shell 5 and the PCB board 1.

[0031] Please see Figure 1 , Figure 2 and Figure 3 The positioning groove and the opening 6 are connected by a guide channel. In this embodiment, the guide channel can be designed to precisely inject adhesive into the positioning groove. For example, the positioning groove in this embodiment is a cubic groove, which has a plate body on all five sides except the side that contacts the PCB board 1, which is open. The space in the protective shell 5, except for the positioning groove, can be solid. The guide channel is opened in the solid body and the top plate of the positioning groove is opened through, so that the adhesive can flow along the guide channel to the hole on the top plate and flow into the positioning groove. Preferably, the guide channel can also be filled with adhesive. On the one hand, this can prevent the fluorinated coolant from approaching the adhesive block 4 from the guide channel. On the other hand, it can also serve as a prompt to stop injecting adhesive. When the adhesive is about to overflow the guide channel, the adhesive injection can be stopped.

[0032] Please see Figure 1 , Figure 2 and Figure 3 The protective shell 5 can be a plastic shell or a metal shell. In this embodiment, the protective shell 5 can be made of either plastic or metal. This embodiment does not limit this, but using metal will have a better effect, but the cost will increase. In actual production, a trade-off can be made.

[0033] Please see Figure 1 , Figure 2 and Figure 3 The protective shell 5 is mounted on the PCB board 1 by one or more of the following methods: snap-fit, adhesive, and welding. When adhesive is used, an adhesive of the same material as the refractive index-matching adhesive block is used. In this embodiment, the protective shell 5 can be connected to the PCB board 1 by snap-fit. The protective shell 5 has snap-fit ​​posts, and the PCB board has snap-fit ​​grooves 7. The snap-fit ​​posts can be inserted into the snap-fit ​​grooves 7 to facilitate the positioning of the protective shell 5 and also improve the connection strength between the two. Alternatively, adhesive can be used, such as using an adhesive of the same material as the refractive index-matching adhesive block to bond the protective shell 5 at the contact point with the PCB board 1. When the protective shell 5 is made of metal, it can be directly welded to the PCB board 1.

[0034] Please see Figure 1 , Figure 2 and Figure 3 The coupling component includes an optical fiber array 2 or a coupling lens. In this embodiment, the coupling component can be an optical fiber array 2, such as a 45° optical fiber array. Specifically, the transmitting end uses a VCSEL chip 3 array + a 45° transmitting optical fiber array (TFA). The receiving end uses a PD chip 3 array + a 45° receiving optical fiber array (RFA). When coupling with the optical fiber array 2, the fiber end face is precisely polished at a 45° angle to achieve a 90° deflection of the optical path. Tolerance control: fiber position error ±1.0μm, core / cladding concentricity ±0.5μm, Z-axis displacement ≤1.0 μm, coupling tolerance: X / Y axis ±17 μm (1dB loss), Z-axis ±42 μm, angular ±15°.

[0035] Please see Figure 1 , Figure 2 and Figure 3This invention provides a method for manufacturing an immersion liquid-cooled optical module, comprising the following steps: S1, setting a coupling component and a chip 3 on a PCB board 1, and completing the coupling between the coupling component and the chip 3; S2, using a fluorine-based material to prepare a refractive index matching adhesive; S3, encapsulating the prepared refractive index matching adhesive in the coupling optical path between the coupling component and the chip 3; S4, after the refractive index matching adhesive solidifies into a block, completing the subsequent fabrication of the optical module. In this embodiment, this method is designed based on the above-mentioned immersion liquid-cooled optical module and is used to manufacture the above-mentioned immersion liquid-cooled optical module. The refractive index matching adhesive used is the same as in the above embodiment, and the technical effects obtained will not be elaborated here.

[0036] Please see Figure 1 , Figure 2 and Figure 3 The materials used to make the refractive index-matching adhesive include a fluorinated acrylate resin matrix, a UV initiator, a perfluoropolyether diluent, and a fluorinated silane coupling agent. In this embodiment, the adhesive is composed of a combination of multiple materials, specifically including: Main resin: fluorinated acrylate (refractive index 1.48~1.52); Curing agent: UV initiator (e.g., Irgacure 184); Diluent: perfluoropolyether (reduces viscosity to 500~1000 cP); Tackifier: fluorinated silane coupling agent (enhances interfacial bonding). The refractive index matches the fiber cladding (±0.005), reducing reflection loss. Curing conditions: UV (365 nm, 10 mW / cm², 30 s). Fluorinated liquid compatibility: After immersion in FC-72 for 1000 hours, transmittance >95%, volume swelling <0.5% (based on accelerated aging test). The adhesive fills the gaps between the VCSEL and PD fibers, eliminating air interfaces and reducing return loss (RL>40 dB). The cured adhesive block 4 has a shear strength >15 MPa, enabling it to withstand the impact of liquid cooling flow.

[0037] Please see Figure 1 , Figure 2 and Figure 3 During the potting of the refractive index matching adhesive, a protective shell 5 is used to guide and shape the refractive index matching adhesive. The protective shell 5, used in conjunction with the potting process, serves to shape and guide the adhesive; for details, please refer to the above embodiments, which will not be repeated here.

[0038] Please see Figure 1 , Figure 2 and Figure 3Fiber array 2 was selected as the coupling component. The specific fabrication process for the 45° fiber array was as follows: 1. Positioning the fiber (core pitch 127μm) on a V-groove substrate; 2. Fixing fiber array 2 with UV adhesive and grinding to 45°±0.1°; 3. Polishing the end face to Ra<0.05μm to reduce scattering loss. The coupling and encapsulation steps were as follows: 1. Actively aligning the VCSEL / PD chip with fiber array 2 (six-axis fine-tuning stage, accuracy ±0.5μm); 2. Coating refractive index matching adhesive (thickness 50–100μm) to cover the chip-fiber interface; 3. UV curing to form a sealed optical path.

[0039] The following are the specific implementation methods:

[0040] Example 1: 800G Multimode Optical Module

[0041] Component specifications:

[0042] VCSEL: Wavelength 850nm, divergence angle 15°, active region diameter 7μm;

[0043] PD: Response band 840–860nm, sensitive area diameter 50μm;

[0044] Fiber: OM5 multimode fiber (core diameter 50μm, NA=0.2);

[0045] Test conditions: Immersion in FC-72 (flow rate 0.5 m / s), conforming to IEC61300-2-22 thermal cycling standard (-40°C to 85°C);

[0046] Performance parameters: Insertion loss of this optical module is less than or equal to 0.5dB, while that of the air-cooled optical module is less than or equal to 0.7dB; return loss of this optical module is greater than or equal to 40dB, while that of the air-cooled optical module is greater than or equal to 30dB; power consumption of this optical module is 24% lower than that of the air-cooled optical module; and housing temperature of this optical module is at least 25 degrees Celsius lower than that of the air-cooled optical module.

[0047] Example 2: Compatibility Verification of Refractive Index Matching Adhesive

[0048] Test method:

[0049] 1. Immerse the cured colloidal sample in FC-72 at 25°C / 85°C for 500 hours each.

[0050] 2. Measure transmittance (UV-Vis spectrum) and volume change (accuracy 0.01%).

[0051] result:

[0052] Light transmittance remains >95%, with no yellowing.

[0053] At 85°C, the swelling ratio is 0.3% and the refractive index drift is <0.00.

[0054] In addition, this optical module also has the following technical effects:

[0055] 1. Improved heat dissipation efficiency: Fluoride liquid directly contacts the module, reducing PUE (Power Usage Effectiveness) by 30%.

[0056] 2. Optical path stability: Refractive index matching adhesive eliminates interface reflection, reducing IL by 20% and increasing RL by 10dB.

[0057] 3. Long-term reliability: Passes fluorinated liquid aging test, lifespan > 10 years (accelerated model calculation).

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An immersion liquid-cooled light module, comprising a PCB board, a coupling assembly, and a chip disposed on the PCB board, the chip and the coupling assembly having a coupling light path therebetween, characterized in that: It also includes an adhesive block for wrapping the coupled optical path and a protective shell for shaping the adhesive block. The coupling component includes an optical fiber array. The edge of the adhesive block extends to the optical fiber array and the chip. The adhesive block is a refractive index matching adhesive block made of fluorine-based material. The protective shell has an opening for injecting refractive index matching adhesive. The protective shell has a positioning groove that communicates with the opening and has the same size as the adhesive block. The positioning groove and the opening are connected by a guide channel. The positioning groove is a cubic groove. Except for the side that contacts the PCB board, the other five sides of the cubic groove have a plate body. The space of the protective shell except for the positioning groove is solid. The guide channel is opened in the solid body and opens through the top plate of the positioning groove. The adhesive flows along the guide channel to the hole on the top plate and flows into the positioning groove.

2. The immersion liquid-cooled light module of claim 1, wherein: The protective shell is mounted on the PCB board by one or more of the following methods: snap-fit, adhesive, and welding. When adhesive is used, the adhesive is made of the same material as the adhesive block with the same refractive index.

3. The immersion liquid-cooled light module of claim 1, wherein: The protective shell is either a plastic shell or a metal shell.

4. The immersion liquid-cooled light module of claim 1, wherein: The coupling component includes an optical fiber array or a coupling lens.

5. A method for manufacturing an immersion liquid-cooled optical module, characterized in that, The method for manufacturing an immersion liquid-cooled optical module as described in any one of claims 1-4 includes the following steps: S1, Set up coupling components and chips on the PCB board, and complete the coupling between the coupling components and chips; S2 uses fluorine-based materials to make refractive index matching adhesive; S3, the prepared refractive index matching adhesive is potted into the coupling optical path between the coupling component and the chip; S4. After the refractive index matching adhesive has solidified into a block, the subsequent fabrication of the optical module can be completed.

6. The method of claim 5, wherein: The materials used to make refractive index matching adhesives include a fluorinated acrylate resin matrix, a UV initiator, a perfluoropolyether diluent, and a fluorinated silane coupling agent.

7. The method of claim 5, wherein: When potting the refractive index matching adhesive, a protective shell is used to guide and shape the refractive index matching adhesive.

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