High-power communication laser packaging shell with heat dissipation micro-channel and processing method of high-power communication laser packaging shell

Abstract

The invention provides a high-power communication laser packaging shell with a heat dissipation micro-channel and a processing method, and relates to the technical field of optical communication device packaging, and the high-power communication laser packaging shell comprises an annular frame which is provided with a containing space; the micro-channel heat dissipation assembly is arranged at the bottom of the annular frame, the micro-channel heat dissipation assembly is formed by stacking a plurality of cooling fins, and a micro-channel used for circulating cooling fluid is formed in the micro-channel heat dissipation assembly; the at least two blocking pieces are arranged at the two ends of the micro-channel heat dissipation assembly respectively and used for sealing the micro-channel heat dissipation assembly; and the water inlet pipe and the water outlet pipe are respectively arranged on the corresponding blocking pieces and are communicated with the micro-channel. A plurality of radiating fins with specific hollow structures are stacked and welded into the integrated micro-channel radiating assembly, a complex three-dimensional micro-channel network with a high specific surface area is formed, cooling fluid forms turbulent flow in the micro-channels and fully exchanges heat with the walls of the channels, the radiating efficiency is greatly improved, and the service life of the micro-channel radiating assembly is prolonged. And the overall thermal resistance from the laser chip to the cooling fluid is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of optical communication device packaging technology, and in particular to a high-power communication laser packaging shell with heat dissipation microchannel and its processing method. Background Technology

[0002] With the rapid development of communication technology and the explosive growth of supercomputing centers and AI computing networks, the demand for transmission bandwidth and distance in optical communication systems continues to increase. High-power communication lasers, as core components for optical signal generation, have expanded their application scenarios from long-distance backbone network transmission to short-distance interconnection in data centers, industrial control, and aerospace special communications. The reliability of laser packaging directly determines the lifespan of optical modules and has become a key factor restricting system performance upgrades. The packaging shell, as the core carrier for heat dissipation, has become a crucial factor in ensuring the stable operation of high-power lasers. Currently, mainstream high-power laser packaging forms mainly include butterfly packaging, BOX hermetic packaging, and optoelectronic co-packaging. However, the heat dissipation designs of existing packaging shells all have significant shortcomings. For example, traditional butterfly packaging relies on a solid conduction path of "chip-solder-substrate-heat sink," lacking an independent heat dissipation channel, resulting in low heat dissipation efficiency. Other common heat dissipation structures absorb chip heat through an aluminum base and conduct it to a cooling plate, using a cooling liquid for heat exchange. This method has low heat dissipation efficiency and cannot withstand instantaneous heat dissipation, making it only suitable for low-power optical communication devices. In high-power applications, existing packaging shells cannot meet the requirements of high-power, long-life next-generation optical communication devices due to problems such as lack of heat dissipation channels, unreasonable design, and high thermal resistance. Therefore, developing a packaging shell with heat dissipation microchannels that has efficient heat dissipation capabilities, a compact structure, and reliable processing has become an urgent technical challenge to be solved in the field of high-power optical communication packaging. Summary of the Invention

[0003] The purpose of this invention is to provide a high-power communication laser packaging shell with heat dissipation microchannels and a processing method thereof, so as to solve the problems of low heat dissipation efficiency and high thermal resistance of the packaging shells in the prior art, which cannot meet the application requirements of high-power lasers.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A high-power communication laser package with heat dissipation microchannels, comprising: The ring frame has a accommodating space. The microchannel heat dissipation component is located at the bottom of the ring frame. The microchannel heat dissipation component is composed of multiple heat sinks stacked together, and microchannels for the flow of cooling fluid are formed inside. At least two blocking plates are respectively set at both ends of the microchannel heat dissipation component to seal the microchannel heat dissipation component; The inlet and outlet pipes are respectively installed on the corresponding plugs and connected to the microchannels.

[0005] Preferably, the microchannel heat dissipation assembly includes at least one heat dissipation unit; The heat dissipation unit includes at least one first heat sink, one second heat sink, and one third heat sink; The first heat sink is spaced apart by the second or third heat sink.

[0006] Preferably, the first heat sink includes a first plate body, and the first plate body has a first chamber and a second chamber that are interconnected. The second heat sink includes a second plate body, and the second plate body has a third chamber inside; The third heat sink includes a third body, and the third body has a fourth chamber inside; When the first heat sink, the second heat sink, the third heat sink, and the first heat sink are stacked together, the first chamber and the fourth chamber are aligned and overlapped in the stacking direction, and the second chamber and the third chamber are aligned and overlapped in the stacking direction to form a microchannel.

[0007] Preferably, the first sheet body has a plurality of first extensions and an L-shaped extension inside. The L-shaped extension divides the internal space of the first sheet body into the first chamber and the second chamber, and leaves a communication port to connect the first chamber and the second chamber.

[0008] Preferably, a plurality of first extensions extend inward along the length direction of the first sheet; an L-shaped extension extends from one side of the width direction of the first sheet and extends in a turning direction to between any two adjacent first extensions.

[0009] Preferably, the second sheet has a plurality of second extensions inside, and the second extensions divide the second sheet into a third chamber. The third piece has several third extensions inside, and the third extensions divide the third piece into a fourth chamber.

[0010] Preferably, the microchannel heat dissipation assembly is composed of multiple heat dissipation units, and the two outer ends of the microchannel heat dissipation assembly are a first heat sink and a third heat sink, respectively; and on one side of the third heat sink, an additional first heat sink is provided so that the first heat sink is always adjacent to the third heat sink.

[0011] Preferred options also include: Ceramic strips are placed in the notches at both ends of the ring frame along its length. Lead wires are threaded through the ceramic strip; A sealing ring, placed on top of the ring frame, is used to secure the ceramic strip.

[0012] A method for processing a packaging shell includes the following steps: 1) Provide several heat sink blanks, and form hollow grooves on the blanks by etching or laser processing to obtain the first heat sink, the second heat sink and the third heat sink; 2) Stack the first heat sink, the second heat sink, and the third heat sink in a preset order; 3) Diffusion welding is performed on the stacked heat sinks to form an integrated microchannel heat dissipation component; 4) The microchannel heat dissipation component is brazed to the ring frame.

[0013] Preferably, the diffusion welding process is vacuum thermopress diffusion welding, with a welding temperature of 800℃-1000℃, a pressure of 8-12 MPa, and a vacuum degree not inferior to 5×10⁻⁶. -2 Pa; Before the brazing connection, the surface to be welded of the microchannel heat dissipation component and the ring frame is further subjected to mechanical processing to ensure that the surface roughness is not greater than 0.5μm and the flatness is not greater than 0.5μm. After the brazing connection, the process also includes electroplating the welded packaging shell, with the plating layer consisting of a nickel base layer and a gold surface layer.

[0014] The beneficial effects of this invention are: 1. By stacking and welding multiple heat sinks with specific hollow structures into an integrated microchannel heat dissipation component, a complex and high specific surface area three-dimensional microchannel network is formed. The cooling fluid forms turbulence in the microchannel and fully exchanges heat with the channel wall, which greatly improves the heat dissipation efficiency and effectively reduces the overall thermal resistance from the laser chip to the cooling fluid.

[0015] 2. The channel heat dissipation component serves directly as the base of the package shell, integrating heat dissipation and support functions. It eliminates the need for additional heat sinks or cold plates, making the overall package structure more compact, reducing package size and weight, improving integration, and adapting to the development trend of miniaturization and high density of optical modules.

[0016] 3. Through the specific structural design and staggered stacking of the first, second and third heat sinks, the cooling fluid is forced to form a tortuous flow path inside the component. The fluid changes its flow direction multiple times between multiple chambers, extending the flow distance and residence time, ensuring full contact with the extension, thereby achieving more thorough heat exchange. Attached Figure Description

[0017] Figure 1 A schematic diagram of the packaging shell for a high-power communication laser with heat dissipation microchannels; Figure 2 for Figure 1 Side view of the casing shown; Figure 3 This is an assembly diagram of a microchannel heat dissipation component; Figure 4 This is a schematic diagram of the structure of the first heat sink; Figure 5 This is a schematic diagram of the second heat sink. Figure 6 This is a schematic diagram of the third heat sink. Figure 7 Partial assembly diagrams of the first, second, and third heat sinks, as well as enlarged front and back views of certain areas; Figure label: 1. Ring frame; 2. Plug; 3. Ceramic strip; 4. Lead wire; 5. Conduit; 6. Microchannel heat dissipation assembly; 7. Inlet pipe; 8. Outlet pipe; 9. Sealing ring; 6a. First heat sink; 11. First heat sink body; 12. First extension; 13. L-shaped extension; 14. First chamber; 15. Second chamber; 6b. Second heat sink; 21. Second heat sink body; 22. Second extension; 23. Third chamber; 6c, Third heat sink; 31, Third plate; 32, Third extension; 33, Fourth chamber. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0020] Specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0021] Example 1 This embodiment provides a high-power communication laser package housing with heat dissipation microchannels. Please refer to [link / reference]. Figures 1-7 Its main structure includes a ring frame 1, a microchannel heat dissipation component 6, two plugs 2, two ceramic strips 3, several leads 4, a sealing ring 9, and at least one conduit 5.

[0022] The ring frame 1 is preferably made of Kovar alloy and has a rectangular frame structure, forming an internal space for housing the laser chip and other optoelectronic components. Pre-set notches are formed on the sidewalls at both ends of the ring frame 1 along its length. The ceramic strips 3 are made of electrically insulating and thermally conductive ceramic material. Each ceramic strip 3 is embedded in one of the notches in the ring frame 1, with one part extending into the housing space and the other part extending outwards. Metallized wiring is pre-set on the ceramic strips 3 for connecting the leads 4, enabling the transmission of electrical signals from the outside of the package to its interior.

[0023] The sealing ring 9 is also preferably made of Kovar alloy, and its shape matches the top contour of the ring frame 1. Through seam welding or parallel seam welding, the sealing ring 9 can cover and seal the top of the ring frame 1, while firmly pressing and fixing the ceramic strip 3 in the notch, ensuring the hermeticity of the encapsulation. A conduit 5 is also provided on one side wall of the ring frame 1 in the width direction. This conduit 5 is used for the introduction and fixation of optical fibers to enable the external output of optical signals from inside the encapsulation.

[0024] The core of this embodiment lies in the microchannel heat dissipation assembly 6 located at the bottom of the ring frame 1. The microchannel heat dissipation assembly 6 is an integral structure composed of multiple layers of stacked and bonded heat sinks, with plugs 2 welded to both ends to form a closed fluid cavity. Inlet pipes 7 and outlet pipes 8 are respectively opened and connected to the plugs 2 for connection to an external cooling circulation system. Specifically, the pipe on one plug 2 serves as the inlet pipe 7, used to introduce low-temperature cooling fluid; the pipe on the other plug 2 serves as the outlet pipe 8, used to discharge high-temperature cooling fluid that has absorbed heat.

[0025] The microchannel heat dissipation assembly 6 is composed of a plurality of first heat sinks 6a, second heat sinks 6b, and third heat sinks 6c stacked alternately. In this embodiment, these heat sinks are manufactured by precision etching or microprocessor technology, and their stacking order can be a repetition of one or more heat dissipation units. A typical heat dissipation unit can be composed of the sequence "first heat sink 6a - second heat sink 6b - first heat sink 6a - third heat sink 6c". In the assembly composed of multiple heat dissipation units, for the sake of structural integrity and flow channel symmetry, the outermost two layers of the assembly are preferably first heat sinks 6a.

[0026] A specific stacking example is as follows: First heat sink 6a — Second heat sink 6b — First heat sink 6a — Third heat sink 6c — First heat sink 6a — Second heat sink 6b — First heat sink 6a — Third heat sink 6c — First heat sink 6a. In this structure, it is ensured that any two first heat sinks 6a are always separated by a second heat sink 6b or a third heat sink 6c.

[0027] Please see Figure 4The first heat sink 6a includes a first plate 11, with several strip-shaped first extensions 12 and an L-shaped extension 13 within its internal space. The first extensions 12 extend inward from one end in the length direction but do not penetrate the entire plate; they are parallel to each other and spaced apart. The L-shaped extension 13 extends from one side wall in the width direction, with one end inserted into the gap between any two adjacent first extensions 12. This structural design, with the L-shaped extension 13 as the boundary, naturally divides the internal space of the first plate 11 into a first chamber 14 and a second chamber 15. The first chamber 14 is located on the side where the first extensions 12 are located, while the second chamber 15 is located on the other side. Importantly, the first chamber 14 and the second chamber 15 are interconnected in the area not blocked by the L-shaped extension 13, forming a channel for fluid diversion.

[0028] Please see Figure 5 The second heat sink 6b includes a second plate 21, and the second plate 21 has a plurality of strip-shaped second extensions 22 inside. The layout and size of these second extensions 22 are carefully designed so that when the second heat sink 6b is stacked with the first heat sink 6a, the internal space formed therein, namely the third chamber 23, can overlap with the second chamber 15 of the first heat sink 6a in the vertical projection direction.

[0029] Please see Figure 6 The third heat sink 6c includes a third body 31, and the third body 31 has a plurality of strip-shaped third extensions 32 inside. Similarly, the layout and size of these third extensions 32 are designed such that the internal space they form, i.e., the fourth chamber 33, can overlap with the first chamber 14 of the first heat sink 6a in the vertical projection direction.

[0030] Working principle and fluid path: When multiple layers of heat sinks are stacked and bonded in the manner described above, the chambers of each layer are interconnected in three-dimensional space, forming a complex and efficient microchannel network.

[0031] Cooling fluid enters one end of the microchannel heat dissipation assembly 6 through the inlet pipe 7. It is assumed that the fluid first enters the composite chamber formed by the overlap of the first chamber 14, the fourth chamber 33, and the first chamber 14. In this composite chamber, the fluid flows along the gap between the first extension 12 and the third extension 32 of each layer, and the first heat exchange occurs.

[0032] When the fluid reaches the vicinity of the L-shaped extension 13, due to the obstruction of the flow channel, it is forced to pass through the connection between the first chamber 14 and the second chamber 15 in each layer of the first heat sink 6a, and then turn and enter another composite chamber formed by the overlap of the second chamber 15, the third chamber 23, and the second chamber 15.

[0033] Next, the fluid flows in reverse within this new composite chamber, passing through the second extension 22 of each layer for a second heat exchange.

[0034] If the microchannel heat dissipation component 6 contains multiple heat dissipation units, the fluid will repeat the above-mentioned flow pattern of reversal-turning-reversal, which greatly prolongs the flow path and residence time of the fluid at the bottom of the package. This tortuous flow channel design not only significantly increases the heat exchange surface area, but also forces the fluid to generate disturbances, destroying the heat transfer boundary layer, thereby achieving an extremely high convective heat transfer coefficient.

[0035] Finally, the cooling fluid that has absorbed a large amount of heat is collected from the other end of the microchannel heat dissipation component 6 and discharged through the water outlet pipe 8. The heat generated when the laser chip is working is transferred to the top surface of the microchannel heat dissipation component 6 through its welding layer, and then quickly carried away by the high-speed flowing cooling fluid inside, thereby ensuring that the laser chip works within a suitable temperature range and guaranteeing its high performance and long life.

[0036] Example 2 This embodiment proposes a method for fabricating the high-power communication laser packaging shell with heat dissipation microchannels as described in Embodiment 1. The fabrication steps are as follows: 1) Select a 0.5mm thick CMC board, coat the board surface with photoresist, expose and develop it through a mask to form a protective layer for the required heat sink hollow pattern, then immerse the board in an etching solution for chemical etching or use a high-power laser for high-precision cutting to accurately manufacture the internal fine structure of the first heat sink 6a, the second heat sink 6b and the third heat sink 6c. Finally, clean and cut the processed board to obtain a single heat sink. 2) Select block CMC material, and use a CNC milling machine to process the outer contour of the plug plate 2 and the internal fluid distribution cavity. Then drill holes and tap the plug plate 2 for subsequent connection of the inlet pipe 7 and the outlet pipe 8. 3) Prepare a fixture. First, place a blocking plate 2 on the positioning pin of the fixture. Then, strictly follow the unit order of the first heat sink 6a - the second heat sink 6b - the first heat sink 6a - the third heat sink 6c, and stack the three heat sinks layer by layer until the required thickness is reached. Then, cover the top blocking plate 2 and finally press and fix the entire stack in the fixture. 4) Move the entire fixture containing the parts to be welded into the vacuum thermostatic diffusion welding furnace. The program controls the initial evacuation of the furnace to 5×10⁻⁶. -2 The temperature is below 950℃, and then slowly increased to 950℃. After reaching the predetermined temperature, a pressure of 8-12MPa is applied to the block through the hydraulic system, and the temperature and pressure are maintained for 2 hours. 5) Perform quality inspection on the integrated microchannel heat dissipation component 6 formed by diffusion welding, such as X-ray non-destructive testing to check whether the internal channels are intact, and airtightness test to check for leaks. Then, perform precision grinding and polishing on the top surface that needs to be welded to the ring frame 1 so that its surface roughness Ra≤0.5μm and flatness≤0.5μm. 6) The processed microchannel heat dissipation component 6 is subjected to chemical nickel plating. By controlling the plating solution formula and time, a uniform and dense nickel-phosphorus alloy layer with a thickness of ≥10μm is covered on all its inner and outer surfaces. 7) Assemble and position all parts, including the nickel-plated microchannel heat dissipation component 6, the ring frame 1, the ceramic strip 3 with pre-welded leads 4, and the conduit 5, in a dedicated brazing fixture. Place or apply Ag72Cu28 silver-copper eutectic brazing filler / paste at each weld joint. Then, send the entire component into a hydrogen protective atmosphere furnace or a vacuum brazing furnace, heat it to 840℃-860℃ and hold it at that temperature to melt the brazing filler and fully fill the weld joint. After cooling, a high-strength, high-airtightness integrated encapsulation structure is formed. 8) Perform final surface treatment on the brazed package shell, usually using a two-step electroplating process: first, plate a 5-10μm layer of nickel as a barrier and corrosion-resistant layer, and then plate a 1-3μm layer of gold on top of it.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-power communication laser package housing with heat dissipation microchannels, characterized in that, include: The ring frame has a accommodating space. The microchannel heat dissipation component is located at the bottom of the ring frame. The microchannel heat dissipation component is composed of multiple heat sinks stacked together, and microchannels for the flow of cooling fluid are formed inside. At least two blocking plates are respectively set at both ends of the microchannel heat dissipation component to seal the microchannel heat dissipation component; The inlet and outlet pipes are respectively installed on the corresponding plugs and connected to the microchannels.

2. The packaging shell according to claim 1 is characterized in that, The microchannel heat dissipation assembly includes at least one heat dissipation unit; The heat dissipation unit includes at least one first heat sink, one second heat sink, and one third heat sink; The first heat sink is spaced apart by the second or third heat sink.

3. The packaging shell according to claim 2, characterized in that: The first heat sink includes a first plate body, and the first plate body has a first chamber and a second chamber that are interconnected. The second heat sink includes a second plate body, and the second plate body has a third chamber inside; The third heat sink includes a third body, and the third body has a fourth chamber inside; When the first heat sink, the second heat sink, the third heat sink, and the first heat sink are stacked together, the first chamber and the fourth chamber are aligned and overlapped in the stacking direction, and the second chamber and the third chamber are aligned and overlapped in the stacking direction to form a microchannel.

4. The packaging shell according to claim 3, characterized in that, The first sheet body has several first extensions and an L-shaped extension inside. The L-shaped extension divides the internal space of the first sheet body into the first chamber and the second chamber, and leaves a communication port to connect the first chamber and the second chamber.

5. The packaging shell according to claim 4, characterized in that, Several first extensions extend inward along the length direction of the first sheet; an L-shaped extension extends from one side of the width direction of the first sheet and turns to extend between any two adjacent first extensions.

6. The packaging housing according to any one of claims 3 to 5, characterized in that: The second piece has several second extensions inside, and the second extensions divide the second piece into a third chamber. The third piece has several third extensions inside, and the third extensions divide the third piece into a fourth chamber.

7. The packaging shell according to claim 2, characterized in that, The microchannel heat dissipation assembly consists of multiple heat dissipation units, and the two outer ends of the microchannel heat dissipation assembly are a first heat sink and a third heat sink, respectively; and on one side of the third heat sink, an additional first heat sink is provided so that the first heat sink is always adjacent to the third heat sink.

8. The packaging shell according to claim 1, characterized in that, Also includes: Ceramic strips are placed in the notches at both ends of the ring frame along its length. Lead wires are threaded through the ceramic strip; A sealing ring, placed on top of the ring frame, is used to secure the ceramic strip.

9. A method for processing a packaging shell as described in any one of claims 1 to 8, characterized in that, Includes the following steps: 1) Provide several heat sink blanks, and form hollow grooves on the blanks by etching or laser processing to obtain the first heat sink, the second heat sink and the third heat sink; 2) Stack the first heat sink, the second heat sink, and the third heat sink in a preset order; 3) Diffusion welding is performed on the stacked heat sinks to form an integrated microchannel heat dissipation component; 4) The microchannel heat dissipation component is brazed to the ring frame.

10. The processing method according to claim 9, characterized in that, The diffusion welding process is vacuum thermopress diffusion welding, with a welding temperature of 800℃-1000℃, a pressure of 8-12 MPa, and a vacuum degree not inferior to 5×10⁻⁶. -2 Pa; Before the brazing connection, the surface to be welded of the microchannel heat dissipation component and the ring frame is further subjected to mechanical processing to ensure that the surface roughness is not greater than 0.5μm and the flatness is not greater than 0.5μm. After the brazing connection, the process also includes electroplating the welded packaging shell, with the plating layer consisting of a nickel base layer and a gold surface layer.

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