Ceramic-based vapor chamber and preparation method and application thereof

Abstract

The present application relates to a kind of ceramic-based heat plate and its preparation method and application, including single-sided composite board, single-sided composite board is made by metal welding frame, copper clad ceramic sheet, ceramic sheet, copper clad ceramic sheet is sequentially sintered connection, wherein, copper clad ceramic sheet copper material side and metal welding frame sintered connection, copper clad ceramic sheet ceramic material side and ceramic sheet sintered connection, two single-sided composite board is connected to form shell, metal braided belt is arranged in shell;Metal braided belt and the inside of shell sintered connection.The present application can solve the packaging requirements and heat management needs of third-generation semiconductor on the basis of ceramic material of ceramic-based heat plate.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, specifically to a ceramic-based heat exchanger, its preparation method, and its application. Background Technology

[0002] With the continuous development of electronic technology, electronic products such as mobile phones and tablets are becoming increasingly thinner, more integrated, and more powerful. This leads to a continuous increase in the heat flux density of heat-generating components such as chips during operation, posing a significant challenge to the thermal management of electronic products. Therefore, two-phase heat dissipation devices such as vapor chambers and flat heat pipes, with their excellent heat transfer capabilities and ideal thickness, are widely used in the thermal management of electronic products.

[0003] Commonly available vapor chambers are typically made of metals or alloys such as copper, stainless steel, and aluminum. However, their coefficients of thermal expansion differ significantly from those of semiconductor chips, and their chemical stability is poor, making them unsuitable for the packaging requirements of third-generation semiconductors. Therefore, ceramic materials, such as alumina and aluminum nitride, have been widely used in semiconductor device packaging in recent years. However, unlike metals or alloys, ceramic materials have low thermal conductivity, making it difficult to meet the increasing demands of thermal management. Furthermore, existing packaging technologies for ceramic materials are insufficient to meet the long-term reliability requirements of vapor chambers. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one aspect of the technical problem to be solved by the present invention is to propose a ceramic-based heat sink that can meet the packaging requirements and thermal management needs of third-generation semiconductors based on ceramic materials.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] This invention provides a ceramic-based heat spreader, comprising a single-sided composite plate. The single-sided composite plate is formed by sequentially sintering and connecting a metal welded frame, a copper-clad ceramic sheet, a ceramic sheet, and another copper-clad ceramic sheet. The copper material side of the copper-clad ceramic sheet is sintered and connected to the metal welded frame, and the ceramic material side of the copper-clad ceramic sheet is sintered and connected to the ceramic sheet. Two single-sided composite plates are connected to form a shell, and a metal braided strip is disposed inside the shell. The metal braided strip is sintered and connected to the interior of the shell. The shape and size of the three components—the single-sided composite plate and the metal braided strip—in the above technical solution can be customized according to different application scenarios.

[0007] A preferred embodiment of the present invention is that a mesh-like groove is provided on the copper material side of the copper-clad ceramic sheet.

[0008] A preferred embodiment of the present invention is that two metal braided strips are symmetrically arranged.

[0009] The preferred technical solution of the present invention is that the metal welding frame and the metal braided strip are made of copper.

[0010] A preferred embodiment of the present invention is that the ceramic sheet is made of alumina.

[0011] Another aspect of the technical problem solved by the present invention is to provide a method for preparing the above-mentioned ceramic-based heat spreader, comprising the following steps:

[0012] S00: Under helium conditions at 630-670℃, copper-clad ceramic sheets, ceramic sheets, and copper-clad ceramic sheets are stacked in sequence, sintered for 0.5-2 hours, and then held at that temperature for 0.5-1.5 hours to obtain a composite sheet;

[0013] S10: At 630-670℃ under helium conditions, the copper-clad side of the composite sheet is sintered with the metal welding frame for 0.5-2 hours and then held at that temperature for 0.5-1.5 hours to obtain a single-sided composite board.

[0014] S20: A liquid injection port is punched out on a single-sided composite plate;

[0015] S30: Lay the metal braided strip flat on the inner side of the single-sided composite plate, cover it with another single-sided composite plate, and sinter the two single-sided composite plates together after molding to obtain the shell of the unfilled heat spreader plate.

[0016] S40: Weld the injection pipe to the injection port of the unfilled heat spreader, fill and seal the unfilled heat spreader to obtain a ceramic-based heat spreader.

[0017] A preferred embodiment of the present invention is that, in step S30, the metal braided strip undergoes chemical corrosion treatment, thereby giving the treated metal braided strip capillary properties.

[0018] A preferred technical solution of the present invention is that, in S40, a vacuum pump is used to pump the pressure inside the cavity of the unfilled heat spreader to below 0.5 Pa before filling with liquid.

[0019] The preferred technical solution of the present invention is that, in S40, the working fluid for filling is deionized water, and after filling, the solution is frozen to -20°C and then vacuumed to below 0.5Pa before sealing.

[0020] Another aspect of the technical problem solved by the present invention is to provide the application of the above-mentioned ceramic-based heat spreader.

[0021] The beneficial effects of this invention are:

[0022] This invention proposes a ceramic-based vapor chamber, its preparation method, and its application. The single-sided composite plate adopts a sintering structure of copper-clad ceramic sheet-ceramic sheet-copper-clad ceramic sheet. The ceramic material side of each of the two copper-clad ceramic sheets is sintered at high temperature with the upper and lower surfaces of the ceramic sheets, respectively. Finally, a metal welding frame is sintered at high temperature with the copper material side of the copper-clad ceramic sheet. Due to the similar material properties between the connections, the resulting single-sided composite plate has good encapsulation performance and is less prone to encapsulation defects, meeting the long-term reliability requirements of vapor chambers in semiconductor devices. Furthermore, the use of the metal welding frame and metal braided tape achieves shell connection and improves thermal conductivity. The metal welding frame, as the boundary of the shell, connects the single-sided composite plates to form a unified structure. The metal braided tape is placed inside the shell and connected to the sintered single-sided composite plates. The metal braided tape has good thermal conductivity, which can improve the thermal conductivity of the entire structure, allowing heat energy to be conducted more quickly and evenly distributed, further meeting the thermal management requirements of ceramic-based vapor chambers. In summary, the ceramic-based vapor chamber of this invention can meet the packaging and thermal management requirements of third-generation semiconductors.

[0023] In addition, the present invention has the following advantages: 1. It is prepared based on industrial production heat spreaders, which is inexpensive; 2. The preparation steps are simple and convenient to operate; 3. The product structure is simple and the assembly requirements are not high; 4. The parts involved do not have high precision requirements and can be processed under the premise of existing technology. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a perspective view of the ceramic-based heat spreader of Example 1;

[0026] Figure 2 This is an exploded view of the ceramic-based heat spreader of Example 1;

[0027] Figure 3 This is an exploded view of the single-sided composite panel of Example 1;

[0028] Figure 4 for Figure 3 Enlarged view of part A;

[0029] Figure 5 This is a top view of the copper material side of the copper-clad ceramic sheet in Example 1;

[0030] Figure 6 This is a flowchart of the preparation method in Example 1.

[0031] In the picture:

[0032] 1-Single-sided composite plate; 11-Metal welded frame; 111-Protrusion; 12-Copper-clad ceramic sheet; 121-Mesh groove; 13-Ceramic sheet; 2-Shell; 3-Metal braided strip; 4-Injection port. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] like Figure 1-5As shown, this embodiment provides a ceramic-based heat spreader, comprising a single-sided composite plate 1. The single-sided composite plate 1 includes a metal welded frame 11, a copper-clad ceramic sheet 12, a ceramic sheet 13, and another copper-clad ceramic sheet 12. The metal welded frame 11, the copper-clad ceramic sheet 12, the ceramic sheet 13, and the copper-clad ceramic sheet 12 are sequentially sintered together. The copper material side of the copper-clad ceramic sheet 12 is sintered together with the metal welded frame 11, and the ceramic material side of the copper-clad ceramic sheet 12 is sintered together with the ceramic sheet 13. Two single-sided composite plates 1 are connected to form a shell 2, and a metal braided strip 3 is disposed inside the shell 2. The metal braided strip 3 is sintered together with the interior of the shell 2. The entire ceramic-based heat spreader has a length of 80 mm and a width of 20 mm. In this embodiment, the dimensions of the metal welding frame, copper-clad ceramic sheet, and ceramic sheet are matched. The thickness of the copper-clad ceramic sheet is 0.125 mm, the thickness of the ceramic sheet is 0.2 mm, the length of the metal braided strip is 60 mm, the width is 2 mm, and the thickness is 0.2 mm. The boundary width of the metal welding frame is 3 mm, and the thickness is 0.1 mm. The length and width dimensions of the protrusion 111 of the metal welding frame are 20 mm * 10 mm. In this embodiment, the single-sided composite plate adopts a sintering structure of copper-clad ceramic sheet-ceramic sheet-copper-clad ceramic sheet. The ceramic material side of the two copper-clad ceramic sheets is sintered at high temperature with the upper and lower surfaces of the ceramic sheets, respectively. Finally, the metal welding frame is sintered at high temperature with the copper material side of the copper-clad ceramic sheet. Because the materials connected are similar in properties, the resulting single-sided composite plate has good encapsulation performance and is not prone to encapsulation defects, meeting the long-term reliability requirements of heat spreaders in semiconductor devices. In addition, the use of the metal welding frame and metal braided strip achieves the connection of the shell and improves the thermal conductivity. The welded metal frame serves as the boundary of the shell, connecting the single-sided composite plates to form a unified structure. Metal braided strips are placed inside the shell and sintered with the single-sided composite plates. The metal braided strips possess excellent thermal conductivity, improving the overall thermal conductivity of the structure and enabling faster and more uniform heat conduction and distribution, further meeting the thermal management requirements of the ceramic-based vapor chamber. Furthermore, ceramic materials typically exhibit high hardness and vibration resistance, maintaining stability under vibration and impact conditions. Through the design of the single-sided composite plates in this technical solution, the ceramic sheets are effectively supported and fixed, thereby enhancing the vibration and impact resistance of the entire vapor chamber structure.

[0036] Preferably, a mesh groove 121 is provided on the copper material side of the copper-clad ceramic sheet 12. The mesh groove increases the surface area of ​​the copper material side of the copper-clad ceramic sheet, improving heat transfer efficiency. By increasing the surface area, the conduction speed and uniformity of heat energy within the copper-clad ceramic sheet can be improved, thereby more effectively distributing and transferring heat energy. This can further improve the heating efficiency and heat distribution performance of the entire heat spreader. Moreover, the coefficients of thermal expansion of ceramic and metal materials are usually different, and in the heat spreader, there is a problem of thermal expansion matching between the copper-clad ceramic sheet and the metal welding frame. By providing the mesh groove, the stress concentration problem caused by thermal expansion can be alleviated to a certain extent. The mesh groove provides more degrees of freedom, allowing the copper-clad ceramic sheet to better adapt to the deformation of the metal welding frame during thermal expansion, reducing stress concentration, reducing the impact of thermal stress on the ceramic sheet, and improving the reliability and lifespan of the heat spreader.

[0037] Preferably, two metal braided strips 3 are symmetrically arranged. The symmetrical arrangement of two metal braided strips further optimizes the heat spreader design. This technical solution achieves more uniform heat conduction, improves structural stability, and enhances resistance to vibration and impact. The two metal braided strips can be fixed to opposite sides of the heat spreader, forming a uniform support and damping structure. This design effectively absorbs and disperses the energy generated by external vibrations and impacts, reducing the impact on the internal structure of the heat spreader. These effects contribute to improving the heating performance, durability, and reliability of the heat spreader, making it more suitable for various application scenarios.

[0038] Preferably, the copper material of the copper-clad ceramic sheet 12, the metal welded frame 11, and the metal braided strip 3 are made of copper. Copper has excellent thermal conductivity and is one of the commonly used thermal conductive materials. By using copper as the material for the metal welded frame and the metal braided strip, the heat conduction capacity of the heat spreader can be effectively improved. Copper has excellent thermal conductivity, which can quickly conduct and distribute heat energy, enabling the heat spreader to heat up faster and more evenly, thereby improving heating efficiency and heat distribution performance.

[0039] Furthermore, the ceramic material of the copper-clad ceramic sheet 12 and the ceramic sheet 13 are both alumina. Although the thermal conductivity of ceramic materials is low, alumina has relatively high thermal conductivity. By using alumina ceramic sheets in the heat spreader, heat energy can be rapidly conducted inside the ceramic sheet and distributed to the entire surface of the heat spreader, thus improving the heat spreader performance.

[0040] like Figure 6 As shown, its preparation method is as follows:

[0041] 1. Prepare the metal welding frame 11, copper-clad ceramic sheet 12, and ceramic sheet 13;

[0042] 2. Use an ultrasonic cleaner to immerse the metal welded frame 11, copper-clad ceramic sheet 12, and ceramic sheet 13 in anhydrous ethanol for 1-5 minutes to remove the grease. Then dry them using a hair dryer, oven, or air dryer.

[0043] 3. The prepared metal braided strip 3 is subjected to chemical corrosion treatment. The treated metal braided strip will have good capillary properties. The formation of capillary structure can increase the effective contact area of ​​the metal surface, thereby improving the heat conduction efficiency. More contact area means that more heat can be transferred to the heat spreader through the metal braided strip, thereby improving the heating efficiency and heat spreader performance.

[0044] 4. At 650℃ under helium atmosphere, copper-clad ceramic sheets 12, 13, and 12 are stacked in that order. After sintering under appropriate pressure for 1.5 hours, the mixture is held at that temperature for 1 hour to obtain the composite sheet. The applied pressure can be between 2-10 kg for counterweight; in this embodiment, a pressure of 5 kg is used.

[0045] 5. At 650℃ and under helium conditions, the copper-clad side of the composite sheet is sintered with the metal welding frame 11. After sintering for 1.5 hours, the temperature is maintained for 1 hour to obtain a single-sided composite plate 1.

[0046] 6. Use a stamping machine to stamp out the liquid injection port 4 on the sintered single-sided composite plate 1;

[0047] 7. Use a laser to create a mesh-like groove on the copper side of a copper-clad ceramic sheet with a welded metal frame;

[0048] 8. Lay the metal braided strip 3 flat on the inner side of the single-sided composite plate 1, cover it with another single-sided composite plate 1, and sinter the two single-sided composite plates 1 into one piece after mold closing to obtain the shell 2 of the unfilled heat spreader plate. The sintering process is as follows: after mold closing, add 10kg counterweight, sinter at 650℃ for 1.5h in a helium environment, and hold for 1h.

[0049] 9. Weld the injection tube to the injection port 4 of the ceramic-based heat spreader by brazing, and weld the injection tube and the heat spreader together.

[0050] 10. An appropriate amount of working fluid is injected into the inner cavity of the shell 2 through the injection pipe. After freezing, a vacuum is drawn. Specifically, before injection, a vacuum pump is used to evacuate the pressure inside the cavity of the unfilled heat spreader to below 0.5 Pa before injection. By lowering the pressure inside the cavity, gas and air bubbles can be effectively eliminated. The presence of gas and air bubbles inside the heat spreader will affect the uniform distribution of the liquid and the heat conduction performance, leading to uneven temperature or poor heat conduction. Vacuum evacuation can minimize or eliminate the presence of gas and air bubbles, ensuring uniform liquid filling and improving the performance and stability of the heat spreader.

[0051] 11. The working fluid used for filling is deionized water. After filling, the solution is frozen to -20°C and then evacuated to below 0.5 Pa before sealing. Deionized water is a high-purity water in which ions and impurities are removed, resulting in low conductivity and extremely low ion concentration. Using such a working fluid in a vapor chamber reduces the impact of non-thermal conduction, improving the accuracy and uniformity of heat transfer. During freezing, the water freezes, forming ice crystals. Further vacuum extraction effectively removes gas from the ice crystals, preventing their expansion and damage to the vapor chamber. Furthermore, vacuum extraction reduces gas expansion during cooling, ensuring the vapor chamber's sealing and structural integrity.

[0052] 12. After the ceramic-based heat spreader plate has been degassed twice using a heating platform, the tail is removed by resistance welding to complete the overall manufacturing process and obtain the ceramic-based heat spreader plate.

[0053] The structural advantages of this ceramic-based heat spreader are: (1) It adopts a sintering structure of copper-clad ceramic sheet-ceramic sheet-copper-clad ceramic sheet, which can meet the requirements of ceramic heat spreaders in the semiconductor equipment packaging field and reduce the sintering difficulty and cost of ceramic sheets; (2) Moreover, the liquid injection port is realized by stamping a metal welded frame, which simplifies the manufacturing and packaging process of the ceramic-based heat spreader; (3) A mesh groove is laser-processed on the copper material side of the copper-clad ceramic sheet, which helps to optimize the capillary performance of the heat spreader and assist in the recirculation of the working fluid; (4) This invention makes it easy to achieve ultra-thin ceramic-based heat spreaders, making the structure compact.

[0054] The ceramic-based heat spreader in this embodiment also has the following advantages: 1. It is prepared based on industrially produced heat spreaders, resulting in low cost; 2. The preparation steps are simple and convenient to operate; 3. The product structure is simple and the assembly requirements are not high; 4. The parts involved do not have high precision requirements and can be processed under the premise of existing technology.

[0055] This invention has been described through preferred embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. This invention is not limited to the specific embodiments disclosed herein; other embodiments falling within the scope of the claims are also within the protection scope of this invention.

Claims

1. A ceramic-based heat spreader, characterized in that: The composite plate (1) includes a single-sided composite plate (1), which is made by sintering and connecting a metal welded frame (11), a copper-clad ceramic sheet (12), a ceramic sheet (13), and a copper-clad ceramic sheet (12) in sequence. The copper material side of the copper-clad ceramic sheet (12) is sintered and connected to the metal welded frame (11), and the ceramic material side of the copper-clad ceramic sheet (12) is sintered and connected to the ceramic sheet (13). Two single-sided composite plates (1) are connected to form a shell (2), and a metal braided strip (3) is provided inside the shell (2); the metal braided strip (3) and the interior of the shell (2) are sintered together, and a mesh groove (121) is laser-processed on the copper material side of the copper-clad ceramic sheet (12).

2. The ceramic-based heat spreader according to claim 1, characterized in that: The metal braided strip (3) is arranged in two symmetrical positions.

3. The ceramic-based heat spreader according to claim 1, characterized in that: The metal welded frame (11) and the metal braided strip (3) are made of copper.

4. The ceramic-based heat spreader according to claim 1, characterized in that: The ceramic sheet (13) is made of alumina.

5. A method for preparing a ceramic-based heat spreader as described in any one of claims 1-4, characterized in that, Includes the following steps: S00: At 630-670℃, under helium conditions, copper-clad ceramic sheets (12), ceramic sheets (13), and copper-clad ceramic sheets (12) are stacked in sequence, sintered for 0.5-2h and then held at the temperature for 0.5-1.5h to obtain composite sheets; S10: At 630-670℃, under helium conditions, the copper-clad side of the composite sheet is sintered with the metal welding frame (11). After sintering for 0.5-2h, the temperature is maintained for 0.5-1.5h to obtain a single-sided composite plate (1). S20: A liquid injection port (4) is punched out on the single-sided composite plate (1); S30: Lay the metal braided strip (3) flat on the inner side of the single-sided composite plate (1), cover it with another single-sided composite plate (1), and sinter the two single-sided composite plates (1) together after molding to obtain the shell (2) of the unfilled heat spreader. S40: Weld the injection pipe to the injection port (4) of the unfilled heat spreader plate, and perform liquid filling and sealing treatment on the unfilled heat spreader plate to obtain a ceramic-based heat spreader plate.

6. The preparation method according to claim 5, characterized in that: In S30, the metal braided strip (3) is subjected to chemical corrosion treatment to give the treated metal braided strip (3) capillary properties.

7. The preparation method according to claim 5, characterized in that: In S40, before filling with liquid, a vacuum pump is used to reduce the pressure inside the cavity of the unfilled heat spreader to below 0.5 Pa before filling with liquid.

8. The preparation method according to claim 7, characterized in that: In S40, the working fluid for filling is deionized water. After filling, the solution is frozen to -20°C and then evacuated to below 0.5 Pa before sealing.

9. An application of a ceramic-based heat sink as described in any one of claims 1-4 in the field of heat dissipation in semiconductor equipment.

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