Composite wick ceramic vapor chamber
By using the sintering structure and micro/nano structure of substrate-transition layer-metal thermal conductive layer, the problem of easy cracking of ceramic heat sinks during processing and bonding is solved, the heat dissipation performance and interface bonding strength of ceramic heat sinks are improved, and efficient thermal management is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHUHAI DEBIAO PHOTOELECTRIC TECH CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional vapor chambers using metal materials suffer from problems such as heavy weight, poor corrosion resistance, and mismatched coefficients of thermal expansion. This makes ceramic-based vapor chambers prone to cracking during processing and bonding. Furthermore, the interface between the liquid wick and the ceramic substrate is difficult to bond, and delamination or cracking is likely to occur during the preparation process.
A sintered structure of substrate-adhesive-adhesive transition layer-metal thermally conductive layer is adopted, combined with micro-nano structures. The bonding force is enhanced by the micro-nano structures of the metal thermally conductive layer and the lower shell ceramic substrate. Liquid absorbent powder and adhesive are tightly connected by a slurry to improve the interfacial bonding strength. Micro-nano structures are set on the lower shell ceramic substrate to enhance the bonding tensile properties.
The bonding performance between the liquid absorber core and the ceramic substrate of the lower shell is improved, preventing delamination or cracking, enhancing heat dissipation and thermal conductivity, reducing structural damage caused by thermal stress, and improving the tensile strength and heat dissipation efficiency of the composite liquid absorber core ceramic heat spreader.
Smart Images
Figure CN224538568U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat dissipation, and in particular to a composite liquid-absorbing core ceramic heat spreader. Background Technology
[0002] As electronic devices (such as 5G chips, high-power LEDs, and aerospace equipment) become increasingly miniaturized and highly integrated, heat dissipation has become a key bottleneck restricting performance and reliability. Research shows that the reliability of electronic devices is inversely proportional to their operating temperature exceeding specified limits. Therefore, achieving effective thermal management of chip devices is crucial for the steady development of the semiconductor industry. Heat sinks, as a novel and highly efficient phase-change heat transfer device, rapidly transfer heat through the evaporation-condensation cycle of their internal working fluid, becoming a core technology for solving localized heat concentration.
[0003] Traditional heat spreader shells are mostly made of metal materials such as copper, aluminum, and stainless steel. Although metal materials have high thermal conductivity, they have problems such as heavy weight, poor corrosion resistance, and mismatched coefficients of thermal expansion. When used in the semiconductor field, they cannot be directly bonded and there is a risk of cracking due to thermal stress. Ceramic substrates (such as aluminum nitride and alumina) have the advantages of low density, strong corrosion resistance, and adjustable coefficient of thermal expansion, making them an ideal choice to replace metal materials in heat spreaders used in the semiconductor field.
[0004] However, ceramic-based vapor chambers are limited by the material's hardness and brittleness, making them difficult to process, and thus often can only be manufactured as a single unit or encapsulated entirely in metal. Furthermore, the interface between the wick and the ceramic substrate is difficult to bond, and the ceramic substrate is prone to cracking and collapse during the fabrication process. Utility Model Content
[0005] Based on this, and in view of the technical problems existing in the prior art, the purpose of this utility model is to provide a composite liquid absorbent core ceramic heat spreader to make up for the above deficiencies, improve the bonding performance and tensile strength of the liquid absorbent core and the lower shell ceramic substrate while ensuring good thermal conductivity, and prevent delamination or cracking, thus providing a new idea for the forming and packaging of the liquid absorbent core of the ceramic heat spreader.
[0006] A composite liquid-absorbing ceramic heat spreader includes a ceramic shell and a composite liquid-absorbing core. The ceramic shell includes an upper ceramic substrate and a lower ceramic substrate. The upper and lower ceramic substrates each have corresponding first and second shell walls formed by protrusions around their perimeter and corresponding first and second grooves formed by a central depression. The upper ceramic substrate covers the lower ceramic substrate to form a sealable chamber structure composed of the first and second grooves. The composite liquid-absorbing core includes a first liquid-absorbing core fixed to the bottom surface of the first groove and a second composite liquid-absorbing core fixed to the bottom surface of the second groove. The second composite liquid-absorbing core includes a transition layer and a metal thermally conductive layer. The bottom surface of the second groove is provided with a micro / nano structure to increase the bonding force between the lower ceramic substrate and the transition layer. The transition layer is laid on the micro / nano structure and includes liquid-absorbing core powder and a second binder. The second composite liquid-absorbing core and the lower ceramic substrate are integrally sintered. The surfaces of the first and second shell walls are provided with a weldable metal welding layer.
[0007] Compared with existing technologies, the composite liquid-absorbing core ceramic heat spreader of this invention adopts a sintered structure of substrate-adhesive-containing transition layer-metal thermally conductive layer. On the one hand, the metal thermally conductive layer has high porosity and strong thermal conductivity; on the other hand, the transition layer can alleviate the difference in thermal expansion between the metal thermally conductive layer and the lower shell ceramic substrate during the integral sintering process of the second composite liquid-absorbing core and the lower shell ceramic substrate, reducing structural damage caused by thermal stress, improving the interfacial bonding strength between the metal thermally conductive layer and the lower shell ceramic substrate, and preventing delamination or cracking during the preparation or use process. Furthermore, the mixture of liquid-absorbing core powder and the second adhesive can tightly connect the metal thermally conductive layer and the lower shell ceramic substrate, reducing thermal resistance and thus improving heat dissipation. In addition, this invention also sets micro-nano structures on the bottom surface of the second groove of the lower shell ceramic substrate to further enhance the bonding force between the lower shell ceramic substrate and the transition layer, improving the tensile strength and tensile properties of the bond between the lower shell ceramic substrate and the transition layer.
[0008] Furthermore, the micro / nano structure comprises several slots that secure the bottom surface of the transition layer, and the bottom surface of the transition layer has several protrusions that mate with the slots. The micro / nano structure of this composite liquid-absorbing core ceramic heat spreader allows for a tighter bond between the lower shell ceramic substrate and the transition layer, thereby improving its sintering bond strength and tensile strength with the second composite liquid-absorbing core.
[0009] Furthermore, the absorbent core powder includes one or more of copper powder, alumina powder, aluminum nitride powder, and glass powder; the second binder may be one or more of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder.
[0010] Furthermore, the micro / nano structures are formed by mechanical processing or chemical etching.
[0011] Furthermore, the first liquid-absorbing core is in the shape of an inverted cone, arranged in an array on the bottom surface of the first groove, with its bottom fixed to the bottom surface of the first groove and its tip in contact with the upper surface of the second composite liquid-absorbing core. In this design, the conical first liquid-absorbing core of the composite liquid-absorbing core ceramic heat spreader serves two purposes: firstly, it supports the ceramic substrate of the upper shell; secondly, it assists in the reflux of the working fluid, facilitating the rapid flow of the working fluid vapor in the chamber after condensation and liquefaction on the surface of the first liquid-absorbing core to its tip and then to the upper surface of the second composite liquid-absorbing core. This accelerates the internal circulation of the working fluid in the chamber and improves the heat dissipation efficiency of the composite liquid-absorbing core ceramic heat spreader.
[0012] Furthermore, the first absorbent core is formed by sintering a first absorbent core powder with a first binder; the first absorbent core powder includes one or more of copper powder, alumina powder, aluminum nitride powder, and glass powder; the first binder may be one or more of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder.
[0013] Furthermore, the upper surface of the metal thermally conductive layer is provided with thermally conductive grooves. In this solution, the thermally conductive grooves of the composite wick ceramic heat spreader not only serve as channels for the return of the working fluid but also enhance the capillary capacity and thermal conductivity of the second composite wick.
[0014] Furthermore, the first liquid-absorbing core is shaped by a mold on the bottom surface of the first groove, and the first liquid-absorbing core is integrally sintered with the ceramic substrate of the upper shell.
[0015] Furthermore, the top positions of the first shell wall and the second shell wall are respectively provided with injection grooves, and the two oppositely arranged injection grooves form an injection port, which connects the chamber to the external space; the injection port is provided with a copper pipe for injecting working fluid into the chamber; the first shell wall and the second shell wall are connected by brazing.
[0016] Furthermore, the ceramic shell is made of one or more of alumina, aluminum nitride, beryllium oxide, or silicon nitride; the metal welding layer is a nickel layer, a copper cladding layer, or a silver layer.
[0017] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description
[0018] Figure 1 This is a packaging diagram of a composite liquid-absorbing core ceramic heat spreader according to the present invention;
[0019] Figure 2 This is a schematic diagram of the internal structure of a composite liquid-absorbing core ceramic heat spreader according to the present invention;
[0020] Figure 3 This is an enlarged schematic diagram of the slot and protrusion structure described in Example 1;
[0021] Figure 4 This is a schematic diagram of the ceramic shell 1 of a composite liquid-absorbing ceramic heat spreader according to the present invention;
[0022] Figure 5 This is a schematic diagram of the structure of the upper shell ceramic substrate 11 and the first liquid-absorbing core 21 of a composite liquid-absorbing core ceramic heat spreader according to the present invention. Detailed Implementation
[0023] The terminology used in the embodiments of this application is for the purpose of describing specific embodiments only and is not intended to limit the embodiments of this application. It should be understood in this application that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.
[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.
[0025] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0026] In the description of this application, it should be understood that the terms "first," "second," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0028] It should be understood that the embodiments of this application are not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from their scope. The scope of the embodiments of this application is limited only by the appended claims.
[0029] like Figures 1-5 As shown, a composite wicking ceramic heat spreader includes a ceramic shell 1 and a composite wicking core 2. The ceramic shell 1 is made of one or more of alumina, aluminum nitride, beryllium oxide, or silicon nitride, and includes an upper shell ceramic substrate 11 and a lower shell ceramic substrate 12 with the same shape, size, and structure. The upper shell ceramic substrate 11 and the lower shell ceramic substrate 12 each have corresponding first shell walls 13 and second shell walls 14 formed by protrusions around their perimeter, and corresponding first grooves 15 and second grooves 16 formed by recesses in their centers. Injection grooves 17 are respectively provided at the top positions of the corresponding first shell walls 13 and second shell walls 14. The upper shell ceramic substrate 11 covers the lower shell ceramic substrate 12, forming a sealable chamber structure composed of the first grooves 15 and the second grooves 16, and an injection port composed of two opposing injection grooves 17. The injection port connects the chamber to the external space of the composite wicking ceramic heat spreader. The injection port is provided with a copper tube 3 for injecting a working fluid into the chamber. The surfaces of the first shell wall 13 and the second shell wall 14 are provided with a weldable metal welding layer 18, which may be a nickel layer, a copper-clad layer, a silver layer, etc. The upper shell ceramic substrate 11 is sealed on the lower shell ceramic substrate 12. The first shell wall 13 and the second shell wall 14 are connected by brazing, and the solder includes, but is not limited to, solder paste, silver-based solder paste, and glass solder. The composite liquid-absorbing core ceramic heat spreader is vacuumed using a cryogenic working fluid method, sealed by cold pressure, and then sealed by argon arc welding.
[0030] The composite liquid-absorbing core 2 includes a first liquid-absorbing core 21 fixed to the bottom surface of the first groove 15 and a second composite liquid-absorbing core 22 fixed to the bottom surface of the second groove 16. The first liquid-absorbing core 21 and the second composite liquid-absorbing core 22 are located within the cavity. The first liquid-absorbing core 21 can be integrally sintered with the upper shell ceramic substrate 11. The second composite liquid-absorbing core 22 includes an integrally sintered transition layer 221 and a metal thermally conductive layer 222. The transition layer 221 is fixedly connected to the bottom surface of the second groove 16, and the metal thermally conductive layer 222 faces the first liquid-absorbing core 21. The bottom surface of the second groove 16 is provided with a micro / nano structure 19 for increasing the bonding force between the lower shell ceramic substrate 12 and the transition layer 221. The micro / nano structure 19 is a plurality of slots that confine and fix the bottom surface of the transition layer 221, or the micro / nano structure 19 is used to increase the contact area between the bottom surface of the second groove 16 and the bottom surface of the transition layer 221. The micro / nano structure 19 can be formed by machining or chemical etching. The transition layer 221 is laid on the micro / nano structure 19. The bottom surface of the transition layer 221 has several protrusions that are adapted to the slot. The second composite liquid-absorbing core 22 and the lower shell ceramic substrate 12 are integrally sintered. The bottom surface of the transition layer 221 is in close contact with the bottom surface of the second groove 16. The upper surface of the metal thermally conductive layer 222 of the second composite liquid-absorbing core 22 has thermally conductive grooves 2221, preferably V-shaped grooves, formed by mechanical processing or chemical etching. The working fluid can flow along the thermally conductive grooves 2221 on the upper surface of the metal thermally conductive layer 222.
[0031] The first absorbent core 21 is formed by mixing and sintering a first absorbent core powder with a first binder. The first absorbent core powder includes one or more of copper powder, alumina powder, aluminum nitride powder, and glass powder. The first binder can be one or more of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder. The first absorbent core powder is preferably copper powder with a particle size of 40-140 μm, and the binder is preferably aluminum dihydrogen phosphate with a concentration of 200 g / L-700 g / L. The transition layer 221 of the second composite absorbent core 22 is formed by mixing and sintering a second absorbent core powder with a second binder. The second absorbent core powder includes one or more of copper powder, alumina powder, aluminum nitride powder, and glass powder. The second binder can be one or more of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder. The second absorbent core powder is preferably copper powder with a particle size of 40-140 μm, and the second binder is preferably aluminum dihydrogen phosphate with a concentration of 200 g / L-700 g / L.
[0032] A method for preparing a composite liquid-absorbing ceramic heat spreader includes the following steps:
[0033] Step (1): Fabrication of micro / nano structure 19: Micro / nano structure 19 is fabricated on the bottom surface of the second groove 16 of the lower housing ceramic substrate 12 by mechanical processing or chemical etching.
[0034] Step (2): Preparation of the first absorbent core 21: Mix the first absorbent core powder with the first binder, stir and prepare it into the first absorbent core slurry; pour the first absorbent core slurry into the first groove 15 or into the mold fixed in the first groove 15, vacuum dry, and sinter in a furnace at high temperature to obtain the first absorbent core 21.
[0035] Step (3): Preparation of the second composite liquid absorbent core 22: The second liquid absorbent core powder is mixed with the second binder, stirred and prepared into a transition layer slurry; the transition layer slurry is evenly spread in the second groove 16 of the ceramic substrate 12 of the lower shell, and then the material of the metal heat-conducting layer 222 is spread on the transition layer slurry and sintered in a furnace at high temperature to obtain a porous second composite liquid absorbent core 22 including the transition layer-metal heat-conducting layer structure.
[0036] Step (4): Preparation of thermally conductive trench 2221: The thermally conductive trench 2221 is formed on the upper surface of the metal thermally conductive layer of the second composite liquid absorbing core 22 by mechanical processing or chemical etching.
[0037] Step (5): Assembly and packaging: The metal welding layer 18 is plated on the surface of the first shell wall 13 of the upper shell ceramic substrate 11 and the second shell wall 14 of the lower shell ceramic substrate 12. The solder is uniformly coated on the surface of the metal welding layer 18. A copper tube 3 corresponding to the size of the injection port is placed at the injection groove 17 of the second shell wall 14. The upper shell ceramic substrate 11 is placed on the lower shell ceramic substrate 12. The upper shell ceramic substrate 11 and the lower shell ceramic substrate 12 are completely attached and put into the furnace for high-temperature welding and sintering. The working fluid liquid is injected into the chamber through the injection copper tube 3. Then, a vacuum is drawn. After vacuuming, the composite liquid-absorbing core ceramic heat spreader is formed by cold pressure sealing and argon arc welding.
[0038] Furthermore, step (5) employs a freezing working fluid vacuum method, where the freezing temperature is much lower than the freezing temperature of the working fluid liquid, and the composite liquid-absorbing core ceramic heat spreader is kept warm at this freezing temperature.
[0039] Example 1
[0040] A composite liquid-absorbing ceramic heat spreader includes a ceramic shell 1 and a composite liquid-absorbing core 2. The composite liquid-absorbing ceramic heat spreader is evacuated using a refrigerant vacuum method, sealed by cold pressure, and then welded together by argon arc welding.
[0041] The ceramic shell 1 includes an upper shell ceramic substrate 11 and a lower shell ceramic substrate 12 with the same shape, size, and structure. The upper shell ceramic substrate 11 and the lower shell ceramic substrate 12 each have corresponding first shell walls 13 and second shell walls 14 formed by protrusions around their perimeter, and corresponding first grooves 15 and second grooves 16 formed by recesses in their centers. Liquid injection grooves 17 are respectively provided at the top positions of the corresponding first shell walls 13 and second shell walls 14. The upper shell ceramic substrate 11 covers the lower shell ceramic substrate 12, forming a sealable chamber structure composed of the first grooves 15 and second grooves 16, and a liquid injection port composed of the two liquid injection grooves 17. The liquid injection port connects the chamber to the external space of the composite liquid-absorbing core ceramic heat spreader. The height of the chamber is 0.8 mm. The liquid injection port is provided with a copper tube 3 for injecting the working fluid into the chamber. A weldable metal welding layer 18 is provided on the surface of the first shell wall 13 and the surface of the second shell wall 14. The upper shell ceramic substrate 11 is sealed on the lower shell ceramic substrate 12, and the first shell wall 13 and the second shell wall 14 are connected by brazing.
[0042] The composite liquid-absorbing core 2 includes a plurality of first liquid-absorbing cores 21 fixed to the bottom surface of the first groove 15 and a second composite liquid-absorbing core 22 fixed to the bottom surface of the second groove 16. The first liquid-absorbing cores 21 and the second composite liquid-absorbing cores 22 are located within the cavity. The first liquid-absorbing cores 21 are arranged in an array on the bottom surface of the first groove 15. In this embodiment, the first liquid-absorbing core 21 has an inverted conical structure, with its bottom fixed to the bottom surface of the first groove 15 and its tip in contact with the second composite liquid-absorbing core 22. The first liquid-absorbing core 21 is molded onto the bottom surface of the first groove 15, and the first liquid-absorbing core 21 is integrally sintered with the upper shell ceramic substrate 11.
[0043] The second composite absorbent core 22 includes an integrally sintered transition layer 221 and a metal thermally conductive layer 222. The transition layer 221 is fixedly connected to the bottom surface of the second groove 16, and the metal thermally conductive layer 222 faces the first absorbent core 21. The bottom surface of the second groove 16 is provided with micro / nano structures 19 for increasing the bonding force between the lower housing ceramic substrate 12 and the transition layer 221. In this embodiment, the micro / nano structures 19 are several slots that confine and fix the bottom surface of the transition layer 221. The transition layer 221 is laid on the micro / nano structures 19, and the bottom surface of the transition layer 221 is provided with several protrusions 2211 that fit the slots. The second composite absorbent core 22 and the lower housing ceramic substrate 12 are integrally sintered, and the bottom surface of the transition layer 221 is tightly attached to the bottom surface of the second groove 16. In this embodiment, the metal thermally conductive layer 222 is formed by sintering metal powder. The upper surface of the metal thermally conductive layer 222 of the second composite liquid-absorbing core 22 is provided with thermally conductive grooves 2221, and the working fluid can flow along the thermally conductive grooves 2221 on the upper surface of the metal thermally conductive layer 222.
[0044] The preparation method of the composite liquid-absorbing core ceramic heat spreader described in this embodiment includes the following steps:
[0045] Step (1): Fabrication of micro / nano structure 19: The groove is laser-processed on the bottom surface of the second groove 16 of the lower shell ceramic substrate 12.
[0046] Step (2): Preparation of the first absorbent core 21: In an ultrasonic oscillator, copper powder with a particle size of 40 μm and aluminum dihydrogen phosphate solution with a concentration of 500 g / L are mixed at a mass ratio of 8.5:1.5. The mixture is stirred for 10 min in a vacuum mixer to remove bubbles and obtain the first absorbent core slurry. The first absorbent core mold is fixed in the first groove 15 of the ceramic substrate 11 of the upper shell. The first absorbent core slurry is poured into the first absorbent core mold, vacuum dried, sintered in a furnace at 900°C, and demolded to obtain the first absorbent core 21.
[0047] Step (3): Preparation of the second composite liquid absorbent core 22: In an ultrasonic oscillator, copper powder with a particle size of 40 μm and aluminum dihydrogen phosphate solution with a concentration of 500 g / L are mixed at a mass ratio of 8.5:1.5. The mixture is stirred in a vacuum mixer for 10 min to remove bubbles and obtain a transition layer slurry. The transition layer slurry is evenly spread in the second groove 16 of the ceramic substrate 12 of the lower shell. The thickness of the transition layer slurry is 0.6 mm. The metal powder used to prepare the metal heat-conducting layer is evenly spread on the transition layer slurry, leveled, loosened by vibration, dried in a dryer, and then placed in a vacuum sintering furnace. The furnace is ventilated and sintered at 800°C for 2 hours to obtain a porous second composite liquid absorbent core 22 including a transition layer-metal heat-conducting layer structure.
[0048] Step (4): Preparation of thermally conductive groove 2221: A thermally conductive groove 2221 with a width of 150μm, a depth of 200μm, and a spacing of 150μm is processed on the upper surface of the metal thermally conductive layer of the second composite liquid-absorbing core 22 using a laser device.
[0049] Step (5): Assembly and packaging: The metal welding layer 18 is plated on the surface of the first shell wall 13 of the upper shell ceramic substrate 11 and the second shell wall 14 of the lower shell ceramic substrate 12. The solder is uniformly coated on the surface of the metal welding layer 18. A copper tube 3 corresponding to the size of the injection port is placed at the injection groove 17 of the second shell wall 14. The upper shell ceramic substrate 11 is placed on the lower shell ceramic substrate 12. The upper shell ceramic substrate 11 and the lower shell ceramic substrate 12 are completely attached using a clamp and then put into the furnace for welding and sintering at 230°C. After the leak test is qualified, the working fluid liquid is injected into the chamber through the injection copper tube 3. Then, the vacuum is performed by the freezing working fluid vacuum method. After vacuuming, the composite liquid-absorbing core ceramic heat spreader is formed by cold pressing for more than 3 minutes and argon arc welding.
[0050] Example 2
[0051] A composite liquid-absorbing core ceramic heat spreader includes a ceramic shell 1 and a composite liquid-absorbing core 2.
[0052] The ceramic shell 1 and the copper tube 3 at its injection port are the same as in Embodiment 1.
[0053] The composite liquid-absorbing core 2 includes a plurality of first liquid-absorbing cores 21 fixed to the bottom surface of the first groove 15 and a second composite liquid-absorbing core 22 fixed to the bottom surface of the second groove 16. The first liquid-absorbing cores 21 and the second composite liquid-absorbing core 22 are located in the cavity. The first liquid-absorbing cores 21 are the same as in Embodiment 1. The second composite liquid-absorbing core 22 is similar to that in Embodiment 1, except that the metal thermally conductive layer 222 is sintered from metal wire mesh.
[0054] The preparation method of the composite liquid-absorbing core ceramic heat spreader described in this embodiment includes the following steps:
[0055] Step (1): Preparation of micro / nano structure 19: Same as in Example 1.
[0056] Step (2): Preparation of the first absorbent core 21: Same as in Example 1.
[0057] Step (3): Preparation of the second composite liquid-absorbing core 22: In an ultrasonic oscillator, copper powder with a particle size of 40 μm and aluminum dihydrogen phosphate solution with a concentration of 500 g / L are mixed at a mass ratio of 8.5:1.5. The mixture is stirred in a vacuum mixer for 10 min to remove bubbles and obtain a transition layer slurry. The transition layer slurry is evenly spread in the second groove 16 of the ceramic substrate 12 of the lower shell. A metal wire mesh of the same size as the chamber is evenly spread on the transition layer slurry and a pressure block is placed to fix the metal wire mesh. After drying in a dryer, the metal wire mesh is placed in a vacuum sintering furnace, ventilated, and sintered at 800°C for 2 hours to obtain a porous second composite liquid-absorbing core 22 including a transition layer-metal thermal conductive layer structure.
[0058] Step (4): Preparation of thermally conductive trench 2221: Same as in Example 1.
[0059] Step (5): Assembly and packaging: Same as in Example 1.
[0060] In this embodiment, a transition layer 221 between the lower shell ceramic substrate and the metal mesh wick in a composite wick ceramic heat spreader alleviates the thermal expansion differences between the different materials, reduces structural damage, and solves the problem of difficulty in sintering the metal mesh wick on the lower shell ceramic substrate. Furthermore, the grooves in the lower shell ceramic substrate 12 and the protrusions of the transition layer 221 further enhance the interfacial bonding strength between the lower shell ceramic substrate and the metal mesh wick, thereby reducing the thermal resistance of the second wick and improving heat dissipation. In addition, the composite wick ceramic heat spreader of this embodiment uses a metal mesh with a fiber structure to prepare the metal thermally conductive layer 222, which generates high capillary force, giving the heat spreader excellent heat transfer performance.
[0061] Example 3
[0062] A composite liquid-absorbing ceramic heat spreader includes a ceramic shell 1 and a composite liquid-absorbing core 2. The composite liquid-absorbing ceramic heat spreader is evacuated using a refrigerant vacuum method, sealed by cold pressure, and then welded together by argon arc welding.
[0063] The ceramic shell 1 and the copper tube 3 at its injection port are similar to those in Example 1, except that the micro-nano structure 19 is a V-shaped groove.
[0064] The composite liquid-absorbing core 2 includes a first liquid-absorbing core 21 fixed to the bottom surface of the first groove 15 and a second composite liquid-absorbing core 22 fixed to the bottom surface of the second groove 16. The first liquid-absorbing core 21 and the second composite liquid-absorbing core 22 are located in the cavity. The first liquid-absorbing core 21 is integrally sintered with the upper shell ceramic substrate 11.
[0065] The second composite liquid-absorbing core 22 includes an integrally sintered transition layer 221 and a metal thermally conductive layer 222. The transition layer 221 is fixedly connected to the bottom surface of the second groove 16, and the metal thermally conductive layer 222 faces the first liquid-absorbing core 21. The bottom surface of the second groove 16 is provided with a micro / nano structure 19 for increasing the bonding force between the lower housing ceramic substrate 12 and the transition layer 221. The transition layer 221 is laid on the micro / nano structure 19. The second composite liquid-absorbing core 22 and the lower housing ceramic substrate 12 are integrally sintered, and the bottom surface of the transition layer 221 is tightly attached to the bottom surface of the second groove 16. The upper surface of the metal thermally conductive layer 222 of the second composite liquid-absorbing core 22 is provided with thermally conductive grooves 2221, allowing the working fluid to flow along the thermally conductive grooves 2221 on the upper surface of the metal thermally conductive layer 222.
[0066] The preparation method of the composite liquid-absorbing core ceramic heat spreader described in this embodiment includes the following steps:
[0067] Step (1): Fabrication of micro / nano structure 19: V-shaped grooves are laser-processed on the bottom surface of the first groove 15 of the upper shell ceramic substrate 11 and the bottom surface of the second groove 16 of the lower shell ceramic substrate 12, respectively.
[0068] Step (2): Preparation of the first absorbent core 21: In an ultrasonic oscillator, copper powder with a particle size of 40 μm and aluminum dihydrogen phosphate solution with a concentration of 500 g / L are mixed at a mass ratio of 8.5:1.5. The mixture is stirred in a vacuum mixer for 10 min to remove bubbles and obtain the first absorbent core slurry. The first absorbent core slurry is filled into the first groove 15, dried in a dryer, and then sintered in a furnace at 800°C for 2 hours to obtain the first absorbent core 21.
[0069] Step (3): Preparation of the second composite liquid-absorbing core 22: In an ultrasonic oscillator, copper powder with a particle size of 40 μm and aluminum dihydrogen phosphate solution with a concentration of 500 g / L are mixed at a mass ratio of 8.5:1.5. The mixture is stirred in a vacuum mixer for 10 min to remove bubbles and obtain a transition layer slurry. The transition layer slurry is evenly spread in the second groove 16 of the ceramic substrate 12 of the lower shell. Then, the material of the metal heat-conducting layer 222 is spread on the transition layer slurry. After drying in a dryer, the mixture is placed in a vacuum sintering furnace, ventilated, and sintered at 800°C for 2 hours to obtain a porous second composite liquid-absorbing core 22 including a transition layer-metal heat-conducting layer structure.
[0070] Step (4): Preparation of thermally conductive groove 2221: On the upper surface of the first liquid-absorbing core 21 and the upper surface of the metal thermally conductive layer of the second composite liquid-absorbing core 22, coarse V-shaped grooves with a width of 400μm and a depth of 600μm are respectively processed using laser equipment.
[0071] Step (5): Assembly and packaging: Same as in Example 1.
[0072] This invention discloses a composite liquid-absorbing core ceramic heat spreader with a substrate-adhesive-containing transition layer-metal thermally conductive layer sintered structure and micro / nano structure that enhances the bonding force between the lower shell ceramic substrate and the second composite liquid-absorbing core. It utilizes the bonding and sintering properties of copper powder mixed with adhesive and wire mesh to solve the technical challenge of sintering a metal wire mesh layer liquid-absorbing core onto a conventional ceramic substrate. Furthermore, it reduces damage to the liquid-absorbing core and substrate structure caused by thermal stress, preventing delamination or cracking. Simultaneously, it improves the bonding tensile strength and tensile properties of the lower shell ceramic substrate and the second composite liquid-absorbing core, reducing the thermal resistance between them and thus improving heat dissipation. In addition, the structure of the adhesive-containing transition layer-metal thermally conductive layer further improves the porosity and capillary properties of the second composite liquid-absorbing core, thereby enhancing the thermal conductivity of the composite liquid-absorbing core ceramic heat spreader. The composite liquid-absorbing ceramic heat spreader of this invention has strong thermal conductivity, insulation, corrosion resistance, electrical shock resistance, and temperature uniformity. It also has high flatness and is not prone to cracking or collapse during sintering, providing a new approach for the forming and packaging of ceramic heat spreader liquid-absorbing cores.
[0073] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and this utility model also intends to include these modifications and variations.
Claims
1. A composite liquid-absorbing core ceramic heat spreader, characterized in that: The device includes a ceramic shell and a composite absorbent core. The ceramic shell comprises an upper ceramic substrate and a lower ceramic substrate. The upper and lower ceramic substrates each have corresponding first and second shell walls formed by protrusions around their perimeter, and corresponding first and second grooves formed by a central depression. The upper ceramic substrate covers the lower ceramic substrate to form a sealable chamber structure composed of the first and second grooves. The composite absorbent core includes a first absorbent core fixed to the bottom surface of the first groove and a second composite absorbent core fixed to the bottom surface of the second groove. The second composite absorbent core includes a transition layer and a metal thermally conductive layer. The bottom surface of the second groove is provided with a micro / nano structure to increase the bonding force between the lower ceramic substrate and the transition layer. The transition layer is laid on the micro / nano structure and includes absorbent core powder and a second binder. The second composite absorbent core and the lower ceramic substrate are integrally sintered. The surfaces of the first and second shell walls are provided with a weldable metal welding layer.
2. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The micro / nano structure consists of several slots that confine and fix the bottom surface of the transition layer, and the bottom surface of the transition layer is provided with several protrusions that are adapted to the slots.
3. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The absorbent core powder is one of copper powder, alumina powder, aluminum nitride powder, and glass powder; the second binder is one of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder.
4. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The micro / nano structures are formed by mechanical processing or chemical etching.
5. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The first absorbent core is in the shape of an inverted cone and is arranged in an array on the bottom surface of the first groove. Its bottom is fixed to the bottom surface of the first groove, and its tip is in contact with the upper surface of the second composite absorbent core.
6. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The first absorbent core is formed by sintering a first absorbent core powder with a first binder; the first absorbent core powder is one of copper powder, alumina powder, aluminum nitride powder, and glass powder; the first binder is one of aluminum dihydrogen phosphate solution, silicon dioxide, and low-to-medium temperature glass powder.
7. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The upper surface of the metal thermally conductive layer is provided with thermally conductive grooves.
8. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The first liquid-absorbing core is shaped by a mold on the bottom surface of the first groove, and the first liquid-absorbing core is integrally sintered with the ceramic substrate of the upper shell.
9. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The first shell wall and the second shell wall are respectively provided with injection grooves at their top positions. The two oppositely arranged injection grooves form an injection port, which connects the chamber to the external space. The injection port is provided with a copper pipe for injecting working fluid into the chamber. The first shell wall and the second shell wall are connected by brazing.
10. The composite liquid-absorbing core ceramic heat spreader according to claim 1, characterized in that: The ceramic shell is made of one of aluminum oxide, aluminum nitride, beryllium oxide, or silicon nitride; the metal welding layer is one of a nickel layer, a copper cladding layer, or a silver layer.