A semiconductor material evaporator loop heat pipe

Abstract

The application provides a semiconductor material evaporator loop heat pipe, which comprises an evaporator and a cover plate, the cover plate and the evaporator are packaged together, the inlet and outlet of the evaporator are arranged on the cover plate, the cover plate is a silica gel cover plate, and the evaporator is made of silicon-based material. The semiconductor material is used as the raw material of the evaporator, the etching of the capillary microchannel can be realized with high precision, and the semiconductor material can be directly integrated with the chip.

Description

Technical Field

[0001] This invention relates to the field of heat exchange, and particularly to a loop heat pipe. Background Technology

[0002] Heat pipe technology was developed in Los Alamos, USA in 1963. National Laboratory George Grover invented a heat transfer method called a "heat pipe". element It fully utilizes the principles of heat conduction and the rapid heat transfer properties of phase change media to quickly transfer heat from a heating object to the outside of the heat source through a heat pipe. Its thermal conductivity exceeds that of any known metal. Therefore, since its inception, heat pipe technology has become a hot research topic for many scholars both domestically and internationally in recent decades.

[0003] Heat pipe technology, previously widely used in aerospace and military industries, has revolutionized radiator manufacturing since its introduction. It has moved beyond the traditional design approach, moving beyond the reliance on high-airflow motors for optimal cooling. Heat pipe technology has enabled radiators to achieve satisfactory heat exchange, opening up new possibilities in the cooling industry. Currently, heat pipes are widely used in various heat exchange equipment, including in nuclear power and computer fields, such as the utilization of waste heat from nuclear power plants.

[0004] Loop heat pipes are an extension of traditional heat pipe technology and are highly efficient two-phase heat transfer devices. They connect the evaporator and condenser in a loop via vapor and liquid lines, utilizing only capillary force provided by the wick to drive the circulation of the working fluid within the pipe. No additional energy consumption is required; heat is transferred through a phase change in the working fluid. The structural features of loop heat pipes include separate vapor and liquid lines, and an integrated evaporator and compensator. Due to their compact structure, they exhibit low gas-liquid resistance, rapid and flexible start-up, excellent heat transfer capacity, easy installation, and long-distance heat transfer capabilities, making them widely used in military, aerospace, and electronic equipment industries.

[0005] A loop heat pipe (LHP) is a thermal management technology that has gradually developed based on split heat pipe technology. It consists of an evaporator, a condenser, and vapor and liquid piping. The evaporator in a LHP includes a compensation chamber and a vapor chamber, which are connected by a capillary wick. The capillary force provided by the wick drives the circulation of the working fluid. Compared to traditional heat pipes, the more rational capillary structure arrangement and design, as well as the split vapor-liquid piping in LHP, significantly improves the heat transfer distance and system reliability, reduces the circulation resistance of the working fluid within the system, and decreases the system's size, enabling thermal management in complex spaces.

[0006] Current heat pipes are generally based on silicon, with the internal structure etched onto the silicon substrate. This etching process is complex, requiring high-precision, repeatable etching for each manufactured ultrathin silicon-based heat pipe, resulting in high manufacturing costs and posing a significant challenge to its widespread adoption and commercialization. This invention provides a novel loop heat pipe structure that simplifies the internal structure and reduces the complexity of high-precision etching on silicon, thus significantly lowering the manufacturing cost of ultrathin silicon-based loop heat pipes. Furthermore, the new heat pipe can be directly bonded to the heat dissipation source, enabling its application in confined spaces. Additionally, the working fluid in the new heat pipe can directly contact the external environment through external piping, achieving high heat exchange efficiency. Summary of the Invention

[0007] This invention aims to solve at least one of the technical problems existing in the prior art or related technologies. This invention proposes a low-cost, miniaturized, and highly efficient external pipe loop heat pipe system, improving the promotion and commercial application of heat source heat dissipation. To achieve the above objective, the technical solution of this invention is as follows:

[0008] A semiconductor material evaporator loop heat pipe, the loop heat pipe including an evaporator and a cover plate, the cover plate and the evaporator being encapsulated together, the cover plate being provided with an inlet and an outlet of the evaporator, characterized in that the cover plate is a silicone cover plate, and the evaporator is made of silicon-based material.

[0009] Preferably, the evaporator is directly bonded to the silicone cover plate.

[0010] Preferably, the evaporator includes a liquid phase channel, a gas phase channel, and a silicon-based microchannel, wherein the silicon-based microchannel is disposed in a chamber between the liquid phase channel and the gas phase channel.

[0011] Preferably, an external pipeline is also included, which is connected to the bonding body between the silicone cover plate and the evaporator via a connector to form a loop heat pipe.

[0012] Preferably, the external pipeline extends to the outside of the chip via a PTFE pipeline.

[0013] Preferably, the external pipeline is not directly connected to the evaporator, but is connected to the evaporator through the silicone cover female connector and the Luer connector.

[0014] Preferably, the external pipeline is designed as a flexible PTFE pipeline, and the pipeline position can be arranged as needed.

[0015] The loop heat pipe as described in claim 1 is characterized in that the evaporator includes a liquid phase channel, a gas phase channel and a silicon-based microchannel, wherein the silicon-based microchannel is disposed in a cavity between the liquid phase channel and the gas phase channel.

[0016] Microchannels are etched into the interior of the evaporator.

[0017] The microchannel structure inside the evaporator is filled with capillary material including PMMA.

[0018] From the liquid phase to the gas phase, the percentage of PMMA material filling the capillary material increases.

[0019] From the liquid phase to the gas phase, the percentage of PMMA material filling the capillary material gradually increases.

[0020] The location is 100% close to the liquid phase region.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1) This invention uses semiconductor materials as raw materials for evaporators, which can achieve high-precision etching of capillary microchannels. Moreover, the selection of semiconductor materials can enable direct integration with heat dissipation components.

[0023] 2) The loop pipeline is made of PTFE, which is different from the all-silicon crystal design of traditional silicon-based loop heat pipes. It can be bent and shaped, which facilitates the design and layout of the loop pipeline and improves the adaptability to different equipment.

[0024] 3) By replacing the condenser and liquid reservoir in the original structure with external pipes, this invention can reduce the complexity of high-precision silicon-based machining and etching, thus greatly reducing the manufacturing cost of silicon-based loop heat pipes.

[0025] 4) The internal structure of the evaporator of this invention is made of PMMA material. When the heat load input to the evaporator is higher, due to the thermal expansion and contraction characteristics of the material, the higher the heat load, the smaller the gap of the microchannel of the evaporator, and the greater the capillary suction force generated. When the heat is lower, the gap gradually increases, forming the evaporator's adaptive ability to heat load.

[0026] 5) The evaporator in this invention is similar in size to the evaporator in the original silicon-based ultrathin loop heat pipe. Through multiple experiments, the original silicon-based ultrathin loop heat pipe has a high heat dissipation capacity. Furthermore, this invention adds a pipeline for heat exchange with the outside, which further enhances its heat dissipation capacity, thus proving the heat dissipation effect of this new type of heat pipe. Attached Figure Description

[0027] Figure 1 These are exploded views and assembly diagrams of the novel loop heat pipe with external tubing of this invention after it is fitted with the chip;

[0028] Figure 2 This is a schematic diagram of the evaporator silicone cover plate and the chip mating in this invention.

[0029] Figure 3This is a schematic diagram of the silicone cover plate for the novel loop heat pipe of the present invention.

[0030] Figure 4 This is a schematic diagram of the cross-section of the silicone cap plate of the novel loop heat pipe of the external pipeline of the present invention at the through hole;

[0031] Figure 5 This is a schematic diagram of the novel loop heat pipe evaporator with external piping of the present invention.

[0032] Figure 6 This is a partial schematic diagram of the novel loop heat pipe evaporator with external piping of the present invention;

[0033] Figure 7 This is a schematic diagram of the connection between the novel loop heat pipe Luer connector and the pipeline of the present invention.

[0034] The attached diagram is labeled as follows: 1 Evaporator, 2 Silicone cover, 3 Luer connector, 4 PTFE connecting pipe, 5 PTFE external connecting pipe, 6 Chip 2-1 Female connector, 2-2 Evaporator inlet, 2-3 Evaporator outlet, 1-1 Liquid phase zone, 1-2 Gas phase zone, 1-3 Microchannel inside the evaporator chamber. Detailed Implementation

[0035] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] The specific implementation method of the present invention will be further described below with reference to the accompanying drawings.

[0037] Figure 1-7 An external tubing loop heat pipe for use in chips is disclosed. For example... Figure 1 As shown, an external pipeline loop heat pipe includes an evaporator 1, a silicone cover plate 2, and external pipeline sections 3-5. The evaporator 1 and the silicone cover plate 2 are encapsulated together. The silicone cover plate includes a female connector 2-1, an evaporator inlet 2-2, and an evaporator outlet 2-3. The evaporator includes an internal microchannel 1-3, a liquid phase zone 1-1, and a gas phase zone 1-2. The external pipeline includes a Luer connector 3, a PTFE connecting pipe 4, and a PTFE external pipe 5. The external pipeline section not only connects the evaporator inlet and outlet but also functions as the condenser chamber and liquid storage chamber in a traditional ultrathin silicon-based loop heat pipe.

[0038] This invention uses semiconductor materials as raw materials for evaporators, which can achieve high-precision etching of capillary microchannels. Moreover, the selection of semiconductor materials can enable direct integration with heat dissipation components, such as chips.

[0039] This invention uses silicone material for the cover plate, which has the same properties as the semiconductor material of the evaporator, enabling better encapsulation and achieving better integration.

[0040] The loop pipe of this invention uses PTFE pipeline, which is different from the all-silicon crystal design of traditional silicon-based loop heat pipes. It can be bent and shaped, which facilitates the design and layout of the loop pipe and improves its adaptability to different equipment.

[0041] As an improvement, the PTFE connecting pipe 4 and the PTFE outer pipe 5 are integrated structures and manufactured as a single unit.

[0042] This invention reduces the complexity of high-precision silicon-based machining and etching by replacing the condenser and liquid reservoir in the original structure with external pipes, thus greatly reducing the manufacturing cost of silicon-based loop heat pipes.

[0043] Preferably, the external pipeline 3 is designed as a flexible PTFE pipeline, and the position of the pipeline can be arranged as needed.

[0044] As an improvement, microchannels are etched into the interior of the evaporator. The microchannel structure inside the evaporator of this invention is filled with capillary material including PMMA. When the heat load input to the evaporator is higher, due to the thermal expansion and contraction characteristics of the material, the higher the heat load, the smaller the gap of the microchannels in the evaporator, and the greater the capillary suction force generated. When the heat is lower, the gap gradually increases, forming the evaporator's adaptive capability to heat load.

[0045] This invention combines semiconductor material microchannels with PMMA material, which, compared to PMMA material alone, can fully realize capillary action and produce excellent heat absorption and capillary effects.

[0046] As an improvement, the percentage of PMMA material filling the capillary material increases from liquid phase region 1-1 to gas phase region 1-2. This increasing PMMA content leads to a gradual increase in capillary force under high heating conditions from liquid phase region 1-1 to gas phase region 1-2, allowing more liquid to be rapidly drawn into gas phase region 1-2 for evaporation, thus improving evaporation efficiency.

[0047] As an improvement, the percentage of PMMA material filled in the capillary material gradually increases from the liquid phase region 1-1 to the gas phase region 1-2. Preferably, it is 100% near the liquid phase region 1-1. This increasing percentage of PMMA content results in a greater increase in capillary force under high heating conditions from the liquid phase region 1-1 to the gas phase region 1-2, accelerating the flow of more liquid to the gas phase region 1-2 for evaporation and improving evaporation efficiency. This variation was obtained through extensive numerical simulations and experiments and is not common knowledge in the field.

[0048] In this invention, the evaporator is similar in size to the evaporator in the original silicon-based ultrathin loop heat pipe. Through multiple experiments, the original silicon-based ultrathin loop heat pipe has a high heat dissipation capacity. Furthermore, this invention adds a pipeline for heat exchange with the outside, which further enhances its heat dissipation capacity, thus proving the heat dissipation effect of this new type of heat pipe.

[0049] Preferably, the evaporator 1 is directly bonded to the silicone cover plate 2, with the silicone cover plate serving as the evaporator cover plate.

[0050] The external pipeline serves as a condenser, employing a curved loop design and connecting to the heat dissipation components via thermally conductive materials to increase the effective heat exchange area.

[0051] Preferably, the evaporator includes a microchannel 1-3, a liquid phase region 1-1, and a gas phase region 1-2. The microchannels are connected to external pipelines through liquid phase pipelines and gas phase pipelines inlet and outlet.

[0052] Preferably, the external pipeline 3 is not directly connected to the evaporator 1, but is connected to the evaporator through the silicone cover female connector 2-1 and the Luer connector 3.

[0053] Preferably, the silicone cover plate 2 is provided with holes corresponding to the inlet and outlet of the evaporator working fluid, and the inlet and outlet of the external pipeline are connected to the evaporator through the holes 2-2 and 2-3 of the silicone cover plate.

[0054] Preferably, the holes 2-2 and 2-3 of the silicone cover plate are concentric circles with the female connector 2-1 of the silicone cover plate.

[0055] Preferably, the silicon-based microchannels 1-3 are capillary structures. The present invention sets silicon-based microchannels on a silicon substrate, which on the one hand realizes integration with the chip, and on the other hand enables the coolant to quickly return to the evaporation chamber for heat dissipation, thereby improving heat dissipation efficiency.

[0056] like Figure 6 As shown, the internal microchannels of the external loop heat pipe evaporator are arranged in the form of a rectangular parallel microchannel array, with an overall size of 20mm×20mm, a microchannel width of 90μm, a depth of 180μm, and a wall width of 90μm between channels. Because the microchannel structure is made of PMMA material, when the heat load input to the evaporator is higher, due to the thermal expansion and contraction characteristics of the material, the higher the heat load, the smaller the gap between the microchannels of the evaporator, and the greater the capillary suction force generated. When the heat load is lower, the gap gradually increases, forming the evaporator's adaptive capability to the heat load.

[0057] like Figure 7 The external pipeline section shown consists of Luer connector 3, PTFE connecting pipe 4 and PTFE external pipe 5. The components are sealed by interference fit to achieve the required sealing performance.

[0058] like Figure 1 As shown, the evaporator 1 and the silicone cover plate 2 are in direct contact. 1 and 2 are joined by a pressing process, and the evaporator and the silicone cover plate are sealed together. The pressing of the two provides a sealed space inside the evaporator. The Luer connector 3 and the female connector 2-1 of the silicone cover plate are mechanically matched to form a complete radiator structure.

[0059] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0060] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A semiconductor material evaporator loop heat pipe comprising an evaporator and a cover plate, said cover plate and evaporator being encapsulated together, said cover plate having an inlet and an outlet for the evaporator disposed therein, characterized in that, The cover plate is a silica gel cover plate, the evaporator is made of a silicon-based material; the evaporator is directly bonded with the silica gel cover plate; the evaporator comprises a liquid phase channel, a gas phase channel and a silicon-based microchannel, wherein the silicon-based microchannel is arranged in a cavity between the liquid phase channel and the gas phase channel; the microchannel in the evaporator is etched by etching; the microchannel in the evaporator is filled with a capillary material comprising PMMA material; from the liquid phase zone to the gas phase zone, the mass percentage content of the PMMA material filled in the capillary material is higher and higher; the loop heat pipe comprises an external pipe, the external pipe comprises a Luer connector, a PTFE connecting pipe and a PTFE external pipe connected in sequence, wherein the Luer connector connects the inlet and outlet of the evaporator; the external pipe not only plays a role in connecting the inlet and outlet of the evaporator, but also plays a role of the condensing chamber and the liquid storage chamber in the loop heat pipe.

2. The loop heat pipe of claim 1, wherein From the liquid phase zone to the gas phase zone, the mass percentage content of the PMMA material filled in the capillary material gradually increases.

3. The loop heat pipe of claim 2, wherein The mass percentage of the PMMA material filled in the capillary material near the liquid phase zone is 100 percent.

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