A flexible heat-conducting device suitable for an optical module and an optical module

Abstract

This invention belongs to the field of optical module technology, and relates to a flexible heat conductor and an optical module suitable for optical modules. The flexible heat conductor includes a flexible substrate, a flexible heat insulation plate, and flexible capillary heat conduction tubes. The flexible heat insulation plate is sandwiched between two flexible substrates, and the three are pressed together to form a whole plate. The flexible capillary heat conduction tubes are laid around the front and back of the whole plate and are continuous from end to end, forming a closed loop on the outer wall of the whole plate. The inner wall of the flexible capillary heat conduction tubes is covered with a heat absorption core, and the flexible capillary heat conduction tubes are filled with a cooling medium. The flexible capillary heat conduction tubes are arranged side by side and abut against each other to form a capillary array on the whole plate. Because the flexible heat conductor uses a flexible substrate, a flexible heat insulation plate, and flexible capillary heat conduction tubes, a large number of heat conduction channels are integrated in a very small space, resulting in high heat conduction efficiency and large heat conduction capacity. This ensures that the operating temperature of the working chip is controlled within a suitable range, and the working performance of the optical module is more stable and reliable, solving the technical problem of unsatisfactory heat dissipation effect of existing heat sinks.

Description

Technical Field

[0001] This invention relates to the field of optical module technology, and in particular to a flexible heat conductor and optical module suitable for optical modules. Background Technology

[0002] During the heat dissipation process of an optical module, heat is transferred from the optical module to the system mainly through three pathways: thermal conduction, thermal convection, and thermal radiation. Due to their small size and status as miniature devices, forced convection (such as with a fan) is not feasible. Therefore, heat is primarily transferred from the optical module to the outer casing via thermal conduction, and then dissipated through convection. Controlling the internal thermal resistance of the optical module is mainly achieved by increasing the thermal conductivity of the thermally conductive materials to improve thermal conductivity efficiency.

[0003] Currently, in 1.6T optical modules, the DSP chip has a power consumption of up to 25W and a smaller size. The method of using heat dissipation devices (such as metal casings or heat sinks) to directly contact the chip for heat dissipation can no longer meet the heat dissipation requirements, and the optical module cannot work properly.

[0004] Existing optical module heat sinks typically employ air cooling or water cooling (such as Chinese patent CN219123225U), which are limited in form and have limited heat dissipation efficiency. Existing heat pipe shell materials mostly use metals such as copper, aluminum, and stainless steel, relying on the high thermal conductivity and efficient phase change heat transfer of the metal materials themselves. However, the ductility of metal materials is limited. During repeated bending at large angles, not only is the number of bending cycles limited, but the internal channels are also prone to deformation, leading to an increase in local flow resistance of the working fluid, ultimately resulting in a significant decrease in the heat transfer performance of the heat pipe.

[0005] Chinese patent CN212164066U discloses a heat dissipation-friendly optical module employing a flexible heat pipe. The flexible heat pipe, after being bent, is placed in a cavity formed between a main heat sink and a secondary heat sink. One end of the flexible heat pipe connects to the metal heat sink between the main heat sink and the secondary heat sink, while the other end connects to a thermal contact surface. However, this flat flexible heat pipe is prone to deformation at the bends when repeatedly bent at large angles, resulting in a small heat dissipation area and insufficient heat transfer efficiency.

[0006] Therefore, a suitable heat-conducting device is needed to efficiently conduct heat to the heat-generating chip. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a flexible heat conductor and optical module suitable for optical modules, which solves the technical problem that the existing heat sinks cannot meet the heat dissipation requirements of the high-power chips of optical modules and the heat dissipation effect is not ideal.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0011] In a first aspect, embodiments of the present invention provide a flexible heat conductor suitable for optical modules. The lower end of the flexible heat conductor is placed inside the housing of the optical module for contacting the working chip of the optical module, and its upper end passes through the housing for fixed connection with the liquid-cooled and air-cooled integrated heat sink on the housing to conduct heat generated by the working chip. The flexible heat conductor includes a flexible substrate, a flexible heat insulation plate, and flexible capillary heat conduction tubes. The flexible heat insulation plate is sandwiched between two flexible substrates, and the three are pressed together to form a whole plate. The flexible capillary heat conduction tubes are laid around the front and back of the whole plate and are continuous from end to end, forming a closed loop on the outer wall of the whole plate. The inner wall of the flexible capillary heat conduction tubes is covered with a heat absorption core, and the flexible capillary heat conduction tubes are filled with a cooling working fluid. The flexible capillary heat conduction tubes are arranged side by side and abut against each other to form a capillary array on the whole plate.

[0012] Optionally, the bottom surface of the flexible heat conductor contacts at least one working chip for heat conduction, and the heights of the working chips may be the same or different.

[0013] Optionally, the flexible capillary heat pipe includes a heat-absorbing evaporation section, a condensation section, and a reflux section. The heat-absorbing evaporation section is used to conduct heat in contact with the working chip, and the condensation section is used to fit with the liquid-cooled and air-cooled integrated heat sink. The heat-absorbing evaporation section is connected to the condensation section, the condensation section is connected to the reflux section, and the reflux section is connected to the heat-absorbing evaporation section to form a circulating heat conduction path. The cooling medium in the heat-absorbing evaporation section absorbs heat and evaporates. The vaporized cooling medium enters the condensation section and liquefies upon cooling. The liquefied cooling medium enters the reflux section due to the capillary action of the heat-absorbing core and flows back to the heat-absorbing evaporation section.

[0014] Optionally, the cross-sectional area at the end of the condensation section gradually increases along the direction of reflux, forming a pressure-reducing section inside the pipe.

[0015] Optionally, the heat absorption and evaporation sections of multiple flexible capillary heat conduction tubes together constitute a heat absorption and evaporation zone, the condensation sections of multiple flexible capillary heat conduction tubes together constitute a condensation zone, and the reflux sections of multiple flexible capillary heat conduction tubes together constitute a reflux zone; the flexible heat conductor is bent to form a J-shaped structure, and the outer side of the hook-shaped part corresponds to the heat absorption and evaporation zone, and the inner side of the hook-shaped part corresponds to the reflux zone.

[0016] Optionally, the flexible capillary heat pipe may be made of metal composite material, and the heat-absorbing core may be a porous capillary structure that is closely attached to the inner wall of the flexible capillary heat pipe, including but not limited to woven copper wire mesh, polymer fiber core and sintered metal powder core.

[0017] Secondly, embodiments of the present invention provide an optical module, including an upper cover, a bottom shell, a PCB board, a liquid-cooled and air-cooled integrated heat sink, and the aforementioned flexible heat conductor; the upper cover and the bottom shell are connected together to form the outer shell of the optical module, the PCB board is installed in the outer shell, the PCB board is provided with a working chip, the liquid-cooled and air-cooled integrated heat sink is fixed on the top surface of the upper cover, one end of the flexible heat conductor extends into the outer shell and elastically abuts against the working chip, and the other end is welded to the liquid-cooled and air-cooled integrated heat sink outside the outer shell to conduct the heat generated by the working chip to the liquid-cooled and air-cooled integrated heat sink.

[0018] Optionally, the top cover has a window through which one end of the flexible heat conductor extends into the housing.

[0019] Optionally, the liquid-cooled and air-cooled integrated radiator is integrally molded, including a hot plate, liquid-cooled pipes and a cold plate. The hot plate abuts against the flexible heat conductor. The hot plate, liquid-cooled pipes and cold plate are interconnected and sealed with coolant. Gaps are reserved between adjacent liquid-cooled pipes to form air ducts. The air ducts run through opposite ends of the liquid-cooled and air-cooled integrated radiator.

[0020] Optionally, the PCB board has several working chips, and the bottom surface of the flexible heat conductor is elastically attached to at least one working chip.

[0021] (III) Beneficial Effects

[0022] The beneficial effects of this invention are:

[0023] 1. The present invention provides a flexible heat conductor and optical module suitable for optical modules. Because the flexible heat conductor adopts a flexible substrate, a flexible heat insulation plate and a flexible capillary heat conduction tube, it integrates a large number of heat conduction channels in a very small space, achieving extremely high heat dissipation capacity density (heat dissipation capacity per unit volume). It can conduct the heat generated by the working chip to the liquid-cooled and air-cooled integrated heat sink in a timely manner, ensuring that the working temperature of the working chip is controlled within a suitable range. The working performance of the optical module is more stable and reliable. Compared with the prior art, it solves the technical problem that the existing heat sink cannot meet the heat dissipation requirements of the optical module chip and the heat dissipation effect is not ideal.

[0024] 2. Flexible heat conductors are resistant to bending and have high resilience. They are not limited by the chip position and do not take up product structural space. The design is flexible and versatile. They can quickly transfer the heat of one or two working chips at any position on the PCB to the liquid-cooled and air-cooled heat sink. The overall design of the device is more compact and lighter, making it especially suitable for space-constrained application scenarios, such as optical modules, laptops, smartphones, drones, and satellites.

[0025] 3. The liquid-cooled and air-cooled integrated heat sink integrates air cooling and cold pipe multi-channel heat dissipation methods, achieving efficient heat dissipation in a very small size. It can transfer the heat of the condensation zone of the flexible heat conductor in a timely manner, keeping the temperature of the condensation zone of the flexible heat conductor at a low level. This ensures that the vaporized cooling medium in the flexible heat conductor is quickly condensed and liquefied, guaranteeing the smooth and efficient heat transfer of the working chip.

[0026] 4. The optical module uses a flexible heat conductor and a liquid-cooled and air-cooled integrated heat sink in synergy, which can quickly transfer the heat of the working chip, ensuring that the equipment operates stably, reliably and with high performance within a safe temperature range, while meeting the requirements of miniaturization, lightweight and low noise.

[0027] 5. Flexible capillary heat pipes made of polymer materials have both the high thermal conductivity of metals and the superior flexibility and resilience. During repeated bending tests at large angles, the pipes can withstand more cycles of bending without deformation, which would increase the local flow resistance of the cooling medium and ultimately cause a significant decrease in the heat transfer performance of the heat pipe. Therefore, the flexible heat pipes have higher working stability, longer service life, and their heat conduction effect will not decrease due to long-term use.

[0028] 6. The highly elastic flexible capillary heat pipe can directly contact the chip, eliminating the need for an intermediate thermal interface material to conduct heat, reducing contact thermal resistance, and resulting in better heat conduction. Attached Figure Description

[0029] Figure 1 This is a three-dimensional schematic diagram of a flexible heat conductor suitable for optical modules according to the present invention and an embodiment 1 of the optical module.

[0030] Figure 2 This is a schematic diagram of the flexible heat conductor in use, which is an embodiment of the flexible heat conductor suitable for optical modules according to the present invention and an optical module.

[0031] Figure 3 for Figure 2 Schematic diagram of the cross section at point AA;

[0032] Figure 4 for Figure 3 Enlarged view of point C in the middle;

[0033] Figure 5 for Figure 3 Enlarged view of point D;

[0034] Figure 6 for Figure 2 Schematic diagram of the cross section at point BB;

[0035] Figure 7This is a cross-sectional schematic diagram of a flexible heat conductor, which is applicable to an optical module and an optical module according to Embodiment 2 of the present invention.

[0036] Figure 8 This is a three-dimensional schematic diagram of an optical module, which is an embodiment 3 of the flexible heat conductor and optical module applicable to optical modules of the present invention.

[0037] Figure 9 This is one of the exploded view diagrams of an optical module according to Embodiment 3 of the present invention, which describes a flexible heat conductor suitable for optical modules and an optical module.

[0038] Figure 10 This is an exploded view of an optical module, representing Embodiment 3 of the present invention, which is a flexible heat conductor suitable for optical modules. Figure 2 ;

[0039] Figure 11 This is a cross-sectional schematic diagram of an optical module according to Embodiment 3 of the present invention, which is a flexible heat conductor suitable for optical modules.

[0040] Figure 12 This is a three-dimensional schematic diagram of a liquid-cooled and air-cooled integrated heat sink, which is a flexible heat conductor suitable for optical modules and an optical module according to Embodiment 3 of the present invention.

[0041] Figure 13 This is a schematic diagram of the heat dissipation of a liquid-cooled and air-cooled integrated heat sink.

[0042] [Explanation of Labels in the Attached Image]

[0043] 1. Flexible heat conductor; 11. Flexible substrate; 121. Heat absorption and evaporation section; 122. Condensation section; 123. Reflux section; 124. Internal pressure reduction section; 13. Flexible insulation board;

[0044] 2. Top cover; 21. Window; 3. Bottom shell; 4. Operating ear; 5. PCB board; 51. Working chip; 6. Liquid-cooled and air-cooled integrated heat sink; 601. Hot plate; 602. Cold plate; 61. Air duct; 62. Liquid cooling pipe. Detailed Implementation

[0045] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. In this document, directional terms such as "upper" and "lower" are used interchangeably with other directional terms. Figure 9 With the orientation as a reference, the direction of the liquid-cooled and air-cooled integrated heat sink 6 is "up", the direction of the bottom shell 3 is "down", the end where the window 21 of the upper cover 2 is located is "right", and the opposite end of the upper cover 2 is "left".

[0046] This invention provides a flexible heat conductor and an optical module suitable for optical modules. The lower end of the flexible heat conductor is placed inside the outer shell of the optical module for contact with the working chip. Its upper end passes through the outer shell and is fixedly connected to a liquid-cooled / air-cooled integrated heat sink on the outer shell to conduct heat generated by the working chip. The flexible heat conductor includes a flexible substrate, a flexible heat insulation plate, and flexible capillary heat pipes. The flexible heat insulation plate is sandwiched between two flexible substrates, and the three are pressed together to form a single plate. The flexible capillary heat pipes are laid around both sides of the single plate and are continuous, forming a closed-loop pipeline on the outer wall of the single plate. The inner wall of the flexible capillary heat pipes is covered with heat-absorbing materials. The core consists of flexible capillary heat pipes filled with a cooling medium. These flexible capillary heat pipes are arranged side-by-side, forming a capillary array on the entire board. Because the flexible heatsink uses a flexible substrate, flexible insulation plate, and flexible capillary heat pipes, it integrates a large number of heat conduction channels in a very small space, achieving extremely high heat dissipation density (heat dissipation capacity per unit volume). This allows the heat generated by the working chip to be promptly transferred to the liquid-cooled / air-cooled integrated heat sink, ensuring that the working temperature of the working chip is controlled within a suitable range. This results in more stable and reliable optical module performance. Compared to existing technologies, this solves the technical problem that existing heat sinks cannot meet the heat dissipation requirements of optical module chips, leading to unsatisfactory heat dissipation effects.

[0047] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0048] Example 1, refer to Figure 1 , Figure 3 and Figure 11 This embodiment 1 provides a flexible heat conductor suitable for optical modules. The lower end of the flexible heat conductor 1 is placed inside the housing of the optical module to contact the working chip 51 of the optical module. Its upper end passes through the housing and is fixedly connected to the liquid-cooled and air-cooled integrated heat sink 6 on the housing to conduct the heat generated by the working chip 51 during operation. The flexible heat conductor 1 is thin and light, with good bending performance, flexibility and resilience, large heat conduction area and large heat conduction capacity.

[0049] Among them, see Figure 1 and Figure 4The flexible heat conductor 1 includes a flexible substrate 11, a flexible heat insulation plate 13, and flexible capillary heat conduction tubes. The flexible heat insulation plate 13 is sandwiched between two flexible substrates 11, and the three are pressed together to form a whole plate. The flexible capillary heat conduction tubes are laid around the front and back of the whole plate and run through it, forming a closed loop on the outer wall of the whole plate. The inner wall of the flexible capillary heat conduction tubes is covered with a heat absorption core, and the flexible capillary heat conduction tubes are filled with a cooling working fluid. The flexible capillary heat conduction tubes are arranged side by side and abut against each other to form a capillary array on the whole plate.

[0050] See Figures 3 to 5 The flexible heat insulation plate 13 uses a commercially available flexible material with good heat insulation performance, which can be bent and has good resilience. The flexible heat insulation plate 13 prevents the heat from the heat absorption evaporation section 121 from being directly conducted to the return section 123, so that the temperature difference between the two flexible substrates 11 is large, ensuring that there is a sufficient temperature difference between the heat absorption evaporation section 121 and the return section 123, so that the circulating heat conduction of the flexible capillary heat conduction tube can proceed quickly.

[0051] See Figures 1 to 4 The flexible capillary heat pipe includes a heat-absorbing evaporation section 121, a condensation section 122, and a reflux section 123. The heat-absorbing evaporation section 121 is used for heat conduction in contact with the heat source. The condensation section 122 is used for contact with the heat dissipation device. The reflux section 123 is used to return the liquefied cooling medium in the condensation section 122 to the heat-absorbing evaporation section 121. The heat-absorbing evaporation section 121 is connected to the condensation section 122, the condensation section 122 is connected to the reflux section 123, and the reflux section 123 is connected to the heat-absorbing evaporation section 121, forming a circulating heat conduction and dissipation path. The cooling medium in the heat-absorbing evaporation section 121 absorbs heat and evaporates. The vaporized cooling medium enters the condensation section 122, liquefies upon cooling, and releases heat. Due to the capillary action of the heat-absorbing core, the liquefied cooling medium quickly accumulates and flows into the reflux section 123 and back to the heat-absorbing evaporation section 121.

[0052] The amount of cooling medium injected depends on the actual situation, and it is necessary to ensure that the heat-absorbing core is fully saturated and that the heat-absorbing evaporation section 121 has space for vapor diffusion. The cooling medium fills the pores of the heat-absorbing core in the heat-absorbing evaporation section 121, and the liquid level generally does not exceed 90% of the height of the heat-absorbing evaporation section 121.

[0053] See Figure 3 The cooling medium in the heat-absorbing evaporation section 121 absorbs heat and evaporates. The vaporized cooling medium enters the condensation section 122 along the pipe and liquefies upon cooling. The liquefied cooling medium flows back to the heat-absorbing evaporation section 121 under the capillary force of the heat-absorbing core, replenishing the cooling medium in the heat-absorbing evaporation section 121. The cooling medium flowing back to the heat-absorbing evaporation section 121 undergoes a new round of evaporation-liquefaction-recirculation heat conduction process (along the direction of the arrow), and the heat conduction is repeated cyclically.

[0054] It should be noted that the heat absorption and evaporation section 121, the condensation section 122, and the reflux section 123 have the same structure and are named for the convenience of describing the heat conduction process of the cooling working fluid. The heat absorption and evaporation sections 121 of all the flexible capillary heat conduction tubes together constitute the heat absorption and evaporation zone of the flexible heat conductor 1, which is located on the lower end face of the flexible heat conductor 1. The condensation sections 122 of all the flexible capillary heat conduction tubes together constitute the condensation zone of the flexible heat conductor 1, which is located on the top surface of the flexible heat conductor 1. The reflux sections 123 of all the flexible capillary heat conduction tubes together constitute the reflux zone of the flexible heat conductor 1.

[0055] The heat source is the working chip 51, which can be a DSP chip or driver chip in an optical module, or a chip in other electronic devices that requires heat dissipation. The top surface area of ​​the working chip 51 is related to the areas of the heat absorption evaporation zone and the condensation zone as follows: Top surface area of ​​the working chip 51 < Area of ​​the heat absorption evaporation zone < Area of ​​the condensation zone. The cooling medium in the heat absorption evaporation zone absorbs the heat generated by the working chip 51 and evaporates. The vaporized cooling medium enters the condensation zone, where it liquefies upon cooling and releases heat. The heat is transferred from the heat absorption evaporation zone to the condensation zone, and then to the heat dissipation device in contact with the condensation zone.

[0056] As mentioned above, the heat dissipation device that is attached to the condensation section 122 can be a metal casing, a heat sink, or the liquid-cooled / air-cooled integrated heat sink 6, which will be described in detail below. The flexible heat conductor 1 of this application is suitable for heat dissipation of chips in miniature high heat density devices.

[0057] See Figure 1 and Figure 3 As a feasible solution, the flexible substrate 11 is made of a heat-resistant material with a long bending life, such as a thin sheet of polyimide or polyester. The flexible heat conductor 1 is bent into a J-shaped structure, with the outer side of the hook-shaped part corresponding to the heat absorption and evaporation area, the flat part at the junction with the liquid-cooled and air-cooled heat sink (described later) being the condensation area, and the inner side of the hook-shaped part and the adjacent flat part corresponding to the reflux area. By using the J-shaped flexible heat conductor 1, the heat absorption and evaporation area of ​​the hook-shaped part can directly conduct the heat of the working chip 51 to the condensation area, and then conduct it to the liquid-cooled and air-cooled integrated heat sink 6 (described later) through contact. That is, the heat dissipation surface of the working chip 51 is converted into the heat dissipation surface of the condensation area and the liquid-cooled and air-cooled integrated heat sink 6. The flexible heat conductor 1 occupies a very small volume, dissipates heat quickly in the extremely small space of the optical module, and has high thermal conductivity and large heat transfer capacity.

[0058] The flexible heat conductor 1 can be bent into a J-shape, a C-shape, or other shapes, which can be flexibly adjusted according to the actual installation space. The degree of bending of the flexible heat conductor 1, that is, the distance between its upper and lower ends, is set according to the actual installation environment and the thickness of the flexible substrate 11. The bending position of the flexible heat conductor 1 is adjusted according to the actual situation.

[0059] See Figure 5 As a feasible solution, the cross-sectional area of ​​the end of the condensing section 122 gradually increases along the direction of reflux, forming an in-pipe pressure reduction section 124. The cross-sectional shape of the in-pipe pressure reduction section 124 is a right triangle. The in-pipe pressure reduction section 124 is located at the intersection of the condensing section 122 and the reflux section 123, corresponding to the upper side wall of the flexible heat conductor 1.

[0060] The pressure-reducing section 124 inside the pipe creates a pressure difference that guides the thermal circulation. Simultaneously, it reduces liquid reflux resistance, accelerating the replenishment of the cooling medium to the heat-absorbing evaporation section 121 and minimizing steam disturbances that could interfere with the reflux. Under dynamic operating conditions, the pressure-reducing section 124 can guide steam towards the condensation section 122, preventing blockage of the reflux path, ensuring circulation stability, and guaranteeing the circulation efficiency of the cooling medium under complex operating conditions.

[0061] When the flexible heat conductor 1 is started or under unstable operating conditions such as large load changes, the pressure reduction section 124 inside the pipe can provide a better liquid return channel, guiding the steam from the heat absorption evaporation section 121 to the condensation section 122. At the same time, it makes it difficult for the steam to enter the return section 123 in reverse, effectively preventing the vaporized cooling medium from accidentally entering the return section 123 directly from the heat absorption evaporation section 121 and interfering with the rapid return of the liquefied cooling medium, thus ensuring the smooth operation of the flexible heat conductor 1 in circulating heat conduction.

[0062] The end of the condensing section 122 has an increased cross-sectional area along the direction of return flow, forming a pressure-reducing section 124 inside the pipe. This means that the liquid flow area is increased, the resistance of the liquefied cooling medium to return flow is reduced, and the steam pressure decreases when it enters this area. This creates a pressure difference in the pipeline that guides the heat circulation, causing the steam to enter the condensing section 122 from the heat-absorbing evaporating section 121 and condense without backflowing to the return section 123.

[0063] See Figure 4 It should be noted that, under the combined effects of gravity, capillary force, and the bending of the flexible heat conductor 1, a portion of the liquefied cooling medium near the bend in the condensation section 122 flows directly back to the heat-absorbing evaporation section 121. This is the shortest, auxiliary reflux path, accelerating the reflux speed of the cooling medium. In this auxiliary reflux path, the cooling medium flows back to the heat-absorbing evaporation section 121 in a small, continuous, and rapid manner, without interfering with the flow of steam from the heat-absorbing evaporation section 121 to the condensation section 122.

[0064] See Figure 1 and Figure 4 Multiple flexible capillary heat pipes are arranged side by side and connected together for heat conduction. This allows the flexible capillary heat pipes closer to the working chip 51 to transfer heat to the flexible capillary heat pipes farther away from the working chip 51, thus avoiding large temperature differences between different parts of the working chip 51 and preventing heat accumulation in a certain area of ​​the working chip 51, which could lead to "hot spots".

[0065] In some feasible solutions, the flexible capillary heat pipe can be made of metal or metal composite material. The metal composite material is a combination of metal and polymer material, such as copper-based composite material (e.g., copper or copper-nickel alloy capillary tubes coated with polytetrafluoroethylene or epoxy resin). The flexible capillary heat pipe attached and fixed to the flexible substrate 11 possesses both the high thermal conductivity of metal and superior flexibility, bending resistance, and resilience. During repeated bending tests at large angles, not only are the number of cyclic bending increases, but the pipe does not deform, thus avoiding increased local flow resistance of the cooling medium and ultimately a significant decrease in heat transfer performance. Therefore, the flexible heat pipe 1 has higher operational stability, a longer service life, and its heat conduction effect does not decrease with prolonged use. Setting a flexible capillary heat pipe array on the flexible substrate 11 increases the heat dissipation area of ​​the flexible heat pipe 1 within a limited space.

[0066] The heat-absorbing core is a porous capillary structure laid tightly against the inner surface of the flexible capillary heat pipe, and it is a continuous structure, meaning it is continuously laid on the inner wall surface of the heat-absorbing evaporation section 121, the condensation section 122, and the reflux section 123. The heat-absorbing core includes, but is not limited to, woven copper wire mesh, polymer fiber core, and sintered metal powder core, providing capillary force for the liquefied cooling medium, allowing it to quickly flow back to the heat-absorbing evaporation section 121. The heat-absorbing core completely covers the inner wall of the flexible capillary heat pipe without any interruptions, ensuring that there are no areas of capillary force interruption during the cooling medium's reflux process. The continuous heat-absorbing core avoids capillary force interruption under bending conditions, improving the dynamic reliability of the flexible capillary heat pipe. The heat-absorbing core can be made of sintered copper powder with a porosity of 60%–80% and an average pore size of 50μm–200μm.

[0067] In some feasible solutions, the flexible heat conductor 1 uses a copper capillary tube with an inner diameter of 1.2 mm, and the heat-absorbing core is sintered copper powder with 70% porosity, filled with a propylene glycol aqueous solution (boiling point 120℃). The overall dimensions of the J-shaped flexible substrate 11 (thickness 0.2 mm) are 15 mm × 25 mm, wherein the radius of curvature of the hook portion is 1.2 mm, the size of the heat absorption and evaporation zone is 5 mm × 7 mm, a 5 mm × 5 mm DSP chip is mounted on the heat absorption and evaporation zone, the edge distance between the DSP chip and the heat absorption and evaporation zone is 0.5 mm, and the DSP chip and the heat absorption and evaporation zone are coated with 6 W / mK thermal grease (thickness 50 μm), with a clamping force of 10 N.

[0068] See Figure 3 and Figure 11 In this application, the flexible heat conductor 1 is a bent plate-shaped component, the upper end of which is welded to the liquid-cooled and air-cooled integrated heat sink 6. The liquid-cooled and air-cooled integrated heat sink 6 is welded to the upper cover 2 to form an integrated structure. The lower end of the flexible heat conductor 1 is tightly attached to the working chip 51 by its own elasticity.

[0069] See Figure 6Flexible capillary heat pipes are generally square tubes to ensure that the surface of the flexible heat pipe 1 is a flat plane, suitable for contact and heat conduction with the working chip 51 or the liquid-cooled / air-cooled integrated heat sink 6. The flexible capillary heat pipes are fixed to the flexible substrate 11 by means of bonding, pressing, welding, etc. The sidewalls of adjacent flexible capillary heat pipes are bonded together.

[0070] In this application, the cooling medium in the flexible heat conductor 1 includes, but is not limited to, phase change cooling media such as deionized water, ethylene glycol, and propylene glycol aqueous solution.

[0071] It should be noted that pressing the two flexible substrates 11 and the flexible heat insulation plate 13 into a single plate not only provides an attachment and fixing surface for the flexible capillary heat pipe, but also increases the heat dissipation area of ​​the flexible heat conductor 1, enhancing its overall bending resistance and resilience, and making it less prone to excessive bending. Furthermore, the flexible heat conductor 1 forms a J-shape after bending, thus allowing full utilization of the gaps between components of the optical module during installation, maximizing the heat dissipation area while occupying minimal space within the optical module. The flexible heat conductor 1 is not only suitable for heat dissipation in optical modules, but can also be used for heat dissipation in other miniature high-heat-density devices, such as radar systems, CPUs, or GPUs.

[0072] Furthermore, during use, the external force acts on the entire flexible heat conductor 1, the flexible substrate 11, the flexible heat insulation plate 13, and all the flexible capillary heat conduction tubes. In other words, the flexible capillary heat conduction tubes on the flexible heat conductor 1 are subjected to uniform force, making their structure more stable and less prone to deformation, and the pipes less likely to deform and become blocked.

[0073] Example 2, see Figure 7 Unlike Embodiment 1, the flexible heatsink 1 in Embodiment 2 conducts heat to two working chips 51 simultaneously. These two working chips 51 can be chips with the same height or chips with different heights.

[0074] Since the flexible heat conductor 1 uses a flexible substrate 11, a flexible heat insulation plate 13 and a flexible capillary heat conductor tube, it can be bent to a large extent. And because it integrates a large number of heat conduction channels, it has a high heat dissipation capacity density. Therefore, it can conduct heat for two working chips 51 at the same time, with a large heat dissipation volume and high heat dissipation efficiency, and can meet the heat dissipation needs of two working chips 51 at the same time.

[0075] See Figure 7The height of the left working chip 51 is smaller than that of the right working chip 51, and the entire heat-absorbing evaporation section 121 corresponding to the two working chips 51 is filled with cooling medium. The coolant with a lower temperature in the reflux section 123 first flows into the right heat-absorbing evaporation section 121, and then continuously replenishes the left heat-absorbing evaporation section 121 to remove the heat generated by the right working chip 51. The evaporation process is concentrated in the heat-absorbing evaporation section 121 corresponding to the left working chip 51.

[0076] Example 3, referring to Figures 8 to 13 This embodiment 3 provides an optical module, including an upper cover 2, a bottom shell 3, an operating ear 4, a PCB board 5, a liquid-cooled and air-cooled integrated heat sink 6, and the flexible heat conductor 1 of embodiment 1.

[0077] See Figure 9 and Figure 11 The top cover 2 and the bottom shell 3 are connected together by snap-fit ​​and bolt connections to form the outer shell of the optical module. The two sides of the outer shell are snap-fitted together with the operating ears 4. A PCB board 5 is fixedly installed inside the outer shell, and a working chip 51 is mounted on the PCB board 5. A liquid-cooled and air-cooled integrated heat sink 6 is welded and fixed to the top surface of the top cover 2. One end of a flexible heat conductor 1 extends into the outer shell and elastically abuts against the working chip 51, while the other end elastically abuts against and is welded to the liquid-cooled and air-cooled integrated heat sink 6 outside the outer shell, so as to conduct the heat generated by the working chip 51 to the liquid-cooled and air-cooled integrated heat sink 6. The liquid-cooled and air-cooled integrated heat sink 6 integrates pipe liquid cooling and air cooling, resulting in excellent heat dissipation. The liquid-cooled and air-cooled integrated heat sink 6 and the flexible heat conductor 1 work together to dissipate heat from the working chip 51.

[0078] See Figure 9 and Figure 10 In some feasible solutions, the top cover 2 is provided with a window 21, and one end of the flexible heat conductor 1 extends into the outer shell through the window 21. The flexible heat conductor 1 has bending resistance and high resilience, and the space occupied is within the original manufacturing tolerance gap of the optical module. It makes full use of the original gap space of each part of the optical module structure, without increasing the volume of the optical module, and is not limited by the position of the working chip 51. The design is flexible and versatile. The working chip 51 away from the heat sink can also conduct heat to the heat sink with the help of the flexible heat conductor 1. The heat of the working chip 51 at any position on the PCB board 5 can be quickly transferred to the liquid-cooled and air-cooled integrated heat sink 6. The overall design of the device is more compact and lighter. The flexible heat conductor 1 and the liquid-cooled and air-cooled integrated heat sink 6 are used together, which is not only suitable for optical modules, but also for space-constrained application scenarios, such as laptops, smartphones, drones, and satellites.

[0079] See Figures 11 to 13In some feasible solutions, the liquid-cooled and air-cooled integrated radiator 6 includes a hot plate 601, liquid-cooled pipes 62, and a cold plate 602. The hot plate 601 abuts against the flexible heat conductor 1. The hot plate 601, liquid-cooled pipes 62, and cold plate 602 are interconnected and sealed with coolant, forming a three-dimensional pipe network. Gaps are reserved between adjacent liquid-cooled pipes 62 to form air ducts 61, which run through opposite ends of the liquid-cooled and air-cooled integrated radiator 6. The coolant in the hot plate 601, liquid-cooled pipes 62, and cold plate 602 can be deionized water. The coolant in the hot plate 601 absorbs heat from the condensation zone of the flexible heat conductor 1 and transfers it sequentially to the coolant in the liquid-cooled pipes 62 and cold plate 602. During this process, outside air passes through the air duct 61, carrying away heat from the surface of the liquid-cooled pipes 62, helping to dissipate heat to the outside environment, thus achieving synergistic heat dissipation. If the liquid-cooled and air-cooled integrated radiator 6 is missing, the heat in the condensation zone of the flexible heat conductor 1 cannot be transferred. The temperature of the condensation zone is too high, which prevents the vaporized cooling medium from liquefying and thus prevents it from circulating and conducting heat. This will result in the cooling medium in the heat absorption and evaporation zone not being replenished, leading to dry burning.

[0080] See Figure 12 and Figure 13 The air duct 61 has multiple channels, which are triangular prism-shaped.

[0081] See Figure 3 and Figure 6 In actual production, the liquid-cooled and air-cooled integrated heat sink 6 uses materials with high thermal conductivity, generally pure copper, printed using 3D printing technology. The bottom surface of the liquid-cooled and air-cooled integrated heat sink 6 is provided with a mounting groove, and the upper end of the flexible heat conductor 1 is embedded in the mounting groove, further increasing the contact surface between the flexible heat conductor 1 and the liquid-cooled and air-cooled integrated heat sink 6.

[0082] The liquid-cooled and air-cooled integrated heat sink 6 is small in size, and the ultra-thin flexible heat conductor 1 occupies little space, making it suitable for efficient heat dissipation in high-heat-density, micro-devices. The highly elastic flexible heat conductor 1 can directly contact the working chip 51, compensating for the height tolerance of the working chip 51, eliminating the need for additional thermal interface materials to conduct heat, reducing contact thermal resistance, and resulting in higher heat dissipation efficiency.

[0083] Because the flexible heat conductor 1 is made by pressing two flexible substrates 11 and a flexible heat insulation plate 13 into a single plate, and attaching and fixing tiny flexible capillary heat conductors to the front and back of the plate, and bending the flexible heat conductor 1 into a J-shape, it can quickly rebound after being deformed under force. Therefore, the flexible heat conductor 1 has good bending performance and resilience. The internal structure of the flexible capillary heat conductor will not experience increased local flow resistance of the cooling medium due to deformation caused by external forces. Therefore, the heat dissipation performance of the flexible heat conductor 1 remains basically unchanged during the long-term use of the optical module, and the heat dissipation efficiency is high. In other words, the flexible substrate 11, the flexible heat insulation plate 13, and the flexible capillary heat conductor form an inseparable whole, solving the problem that external forces can easily deform the internal structure of the pipes, leading to a decrease in heat dissipation efficiency.

[0084] It should be noted that, due to the small diameter of the flexible capillary heat pipe, if the inside of the pipe deforms, the cooling medium can easily become blocked at the bend, preventing the circulation and heat dissipation from proceeding smoothly. The flexible heat pipe 1 of this application utilizes the flexibility of the flexible substrate 11, the flexible heat insulation plate 13, and the flexible capillary heat pipe materials themselves, as well as the resilience brought by the J-shaped structure, to protect the flexible capillary heat pipe located at the bend of the flexible substrate 11, effectively preventing deformation of the inside of the pipe at that location and solving this problem.

[0085] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0086] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0087] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0088] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0089] 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 modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A flexible heat conductor suitable for optical modules, characterized in that: The lower end of the flexible heat conductor (1) is placed inside the housing of the optical module to contact the working chip (51) of the optical module. Its upper end passes through the housing and is fixedly connected to the liquid-cooled and air-cooled integrated heat sink (6) on the housing to conduct the heat generated by the working chip (51) during operation. The flexible heat conductor (1) includes a flexible substrate (11), a flexible heat insulation plate (13) and a flexible capillary heat conductor. The flexible heat insulation plate (13) is sandwiched between two flexible substrates (11) and the three are pressed together to form a whole plate. The flexible capillary heat conduction tubes are laid around the front and back of the whole plate and are connected end to end, forming a closed loop on the outer wall of the whole plate. The inner wall of the flexible capillary heat conduction tubes is covered with heat absorption cores, and the flexible capillary heat conduction tubes are filled with cooling working fluid. The flexible capillary heat pipe includes a heat absorption and evaporation section (121), a condensation section (122) and a reflux section (123). The cross-sectional area of ​​the end of the condensation section (122) gradually increases along the reflux direction to form a pressure reduction section (124) inside the pipe. Each of the flexible capillary heat-conducting tubes is arranged side by side and abuts against each other to form a capillary array on the whole plate.

2. The flexible heat conductor suitable for optical modules as described in claim 1, characterized in that: The bottom surface of the flexible heat conductor (1) contacts at least one of the working chips (51) for heat conduction, and the heights of the working chips (51) are the same or different.

3. A flexible heat conductor suitable for optical modules as described in claim 1, characterized in that: The heat-absorbing evaporation section (121) is used to contact the working chip (51) for heat conduction, and the condensation section (122) is used to be in contact with the liquid-cooled and air-cooled integrated heat sink (6). The heat-absorbing evaporation section (121) is connected to the condensation section (122), the condensation section (122) is connected to the reflux section (123), and the reflux section (123) is connected to the heat-absorbing evaporation section (121), forming a circulating heat conduction path.

4. A flexible heat conductor suitable for optical modules as described in claim 3, characterized in that: The heat absorption and evaporation sections (121) of the multiple flexible capillary heat conduction tubes together constitute a heat absorption and evaporation zone, the condensation sections (122) of the multiple flexible capillary heat conduction tubes together constitute a condensation zone, and the reflux sections (123) of the multiple flexible capillary heat conduction tubes together constitute a reflux zone. The flexible heat conductor (1) is bent as a whole to form a J-shaped structure, and the outer side of the hook-shaped part corresponds to the heat absorption and evaporation zone, and the inner side of the hook-shaped part corresponds to the reflux zone.

5. A flexible heat conductor suitable for optical modules as described in claim 1, characterized in that: The flexible capillary heat pipe is made of metal composite material, and the heat-absorbing core is a porous capillary structure that is closely attached to the inner wall of the flexible capillary heat pipe, including but not limited to woven copper wire mesh, polymer fiber core and sintered metal powder core.

6. An optical module, characterized in that: Includes a top cover (2), a bottom shell (3), a PCB board (5), a liquid-cooled and air-cooled integrated heat sink (6), and a flexible heat conductor (1) as described in any one of claims 1 to 5; The top cover (2) and the bottom shell (3) are connected together to form the outer shell of the optical module. The PCB board (5) is installed in the outer shell. The PCB board (5) is provided with a working chip (51). The liquid-cooled and air-cooled integrated heat sink (6) is fixed on the top surface of the top cover (2). One end of the flexible heat conductor (1) extends into the outer shell and elastically abuts against the working chip (51). The other end is fixedly connected to the liquid-cooled and air-cooled integrated heat sink (6) outside the outer shell so as to conduct the heat generated by the working chip (51) to the liquid-cooled and air-cooled integrated heat sink (6).

7. An optical module as described in claim 6, characterized in that: The top cover (2) is provided with a window (21), and one end of the flexible heat conductor (1) extends into the outer shell from the window (21).

8. An optical module as described in claim 6, characterized in that: The liquid-cooled and air-cooled integrated radiator (6) is integrally formed and includes a hot plate (601), a liquid-cooled pipe (62) and a cold plate (602). The hot plate (601) abuts against the flexible heat conductor (1). The hot plate (601), the liquid-cooled pipe (62) and the cold plate (602) are interconnected and sealed with coolant to form a three-dimensional pipe network. A gap is reserved between adjacent liquid-cooled pipes (62) to form an air duct (61). The air duct (61) runs through the opposite ends of the liquid-cooled and air-cooled integrated radiator (6).

9. An optical module as described in claim 6, characterized in that: The PCB board (5) is provided with a plurality of the working chips (51), and the bottom surface of the lower end of the flexible heat conductor (1) is elastically attached to at least one of the working chips (51).

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