Open type micro-channel radiator with embedded micro pin fins

Abstract

The utility model discloses an open-type micro-channel radiator with embedded micro-pin fins, which comprises a substrate and a packaging sheet which are arranged in an up-and-down overlapping manner, the packaging sheet is respectively provided with a fluid inlet and a fluid outlet, the substrate is provided with a groove, the middle of the substrate is provided with an open-type micro-channel with embedded micro-pin fins, and the open-type micro-channel with embedded micro-pin fins is arranged in the groove. And the groove areas on the two sides of the micro-channel are inlet and outlet liquid storage grooves. Each micro-channel comprises a plurality of rib walls which are arranged in parallel at intervals in the length direction of the substrate, a micro-channel is formed between every two adjacent rib walls in the front-back direction, the rib walls are communicated with each other, and a plurality of pin ribs are arranged in each micro-channel in the length direction of the substrate. And gaps are formed between the top surfaces of the rib walls among the micro-channels and the packaging sheet and between the pin ribs and the packaging sheet, so that an open structure is formed. According to the invention, the heat dissipation effect is effectively improved, the temperature uniformity and the temperature control capability are enhanced, the pressure drop is effectively controlled to rise, and compared with a closed rectangular micro-channel radiator, the energy consumption is obviously reduced; the performance coefficient is increased by 12.3%, and the comprehensive performance is obviously improved.

Description

Technical Field

[0001] The utility model relates to a cooling device, in particular to a high-power microelectronic chip cooling device. Background Art

[0002] Electronic chips are constantly developing towards high power, high integration, and miniaturization, which leads to increased power consumption per unit area, a sharp increase in transient heat load, and increasingly prominent local hot spot problems, which seriously affect the high-frequency performance and reliability of electronic chips. If the core microchip cannot be cooled in time, excessive temperature and local thermal stress will seriously affect its working performance and even cause system failures or safety accidents. The heat dissipation problem of microelectronic devices has become a key factor restricting the further development of its technology. Therefore, how to efficiently remove the ultra-high heat flow of electronic chips in a tiny space has become the key to the development of the microelectronics industry.

[0003] The current heat dissipation methods of microelectronic devices are mainly divided into active and passive. Active heat dissipation includes: microchannel liquid cooling, liquid spray cooling, liquid jet cooling, micro vapor compression cooling, thermoelectric cooling, etc.; passive heat dissipation includes: heat pipe cooling, phase change material cooling, etc. According to the channel hydraulic diameter D h The division of channel size is a more intuitive and recognized method. Hydraulic diameter D h It refers to four times the ratio of the flow cross-sectional area to the perimeter. Some scholars pointed out that D h Channels ≥3mm are considered regular channels; when 200um <D h <3mm, it is a small channel; when 10um <D h When ≤200um, it is a microchannel. Among them, the microchannel radiator has become an effective solution to the heat dissipation problem of high-power micro devices due to its large surface area / volume ratio, high heat transfer intensity per unit area, light weight, small size, and easy integration. In the article "Flow and Heat Transfer Characteristics in Microchannels with Periodic Turbulence Structures" published in "Chemical Industry Progress" Volume 41, Issue 6, 2022, a structure composed of side wall recesses and central pin ribs was proposed. The flow and heat transfer characteristics of this structure were analyzed, and its comprehensive performance was evaluated. The article points out that although complex structures can improve the overall performance, settings such as turbulence structures will significantly increase flow resistance, increase pressure drop and pump work. At present, the development of micro radiators with excellent heat transfer performance, uniform temperature distribution, and low pump power consumption is the main way to solve the problems that constrain the development of the microelectronics field. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide an open microchannel radiator with embedded micro-needle fins, which can improve the temperature uniformity, heat exchange efficiency and comprehensive performance of the radiator.

[0005] In order to achieve the purpose of the utility model, the utility model adopts the following technical solutions:

[0006] The utility model discloses an open type microchannel heat sink with embedded microneedle ribs, comprising a substrate and a packaging sheet arranged in a stacked manner, wherein the packaging sheet and the substrate are fixedly and sealedly connected to form a closed space between the two, and characterized in that: a fluid inlet and a fluid outlet are respectively provided on the packaging sheet, a groove is provided on the substrate in the closed space, an open type microchannel with embedded microneedle ribs is installed in the middle of the groove, a groove area on one side of the open type microchannel with embedded microneedle ribs is an inlet liquid storage tank, and a groove area on the other side is an outlet liquid storage tank, the open type microchannel with embedded microneedle ribs comprises a plurality of rib walls arranged parallel to each other and spaced apart along the length direction of the substrate, a microchannel is formed between two adjacent rib walls, the microchannels are connected to each other, a plurality of needle ribs are provided in each microchannel and along the length direction of the substrate, a gap is provided between the top surface of the rib wall between the microchannels and the packaging sheet, and between the needle ribs and the packaging sheet; the fluid inlet is connected to the inlet liquid storage tank, the open type microchannel with embedded microneedle ribs, the outlet liquid storage tank and the fluid outlet in sequence.

[0007] The utility model has the following advantages and effects:

[0008] 1. The fluid flows into and out of the radiator vertically, which is convenient for installation and integration;

[0009] 2. The open microchannel structure with embedded micro-needle fins can increase the heat transfer area, enhance fluid disturbance, and improve heat dissipation efficiency and temperature uniformity;

[0010] 3. Compared with the closed rectangular microchannel radiator, the open microchannel radiator can reduce the flow resistance, effectively control the pressure drop increment, reduce the pump power consumption of the liquid cooling system, and improve the comprehensive performance of the liquid cooling system;

[0011] 4. Compared with the open microchannel heat sink, the open microchannel structure with embedded micro-needle fins can effectively reduce the temperature of the heat dissipation surface, improve temperature uniformity, effectively increase heat dissipation, improve heat dissipation efficiency, and significantly improve comprehensive performance, thereby increasing the service life and working stability of high-power electronic chips, and promoting the practical application of new microchannel heat sinks in strategic frontier fields such as aerospace information, national defense and military industry, and information and communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic structural diagram of an open microchannel heat sink with embedded micro-needle fins of the utility model;

[0013] Figure 2 yes Figure 1 The heat sink shown is used for cooling high-power microelectronic devices;

[0014] Figure 3 yes Figure 2 A schematic diagram of the platinum metal film attached to the back of the substrate of the heat sink in the structure shown;

[0015] Figure 4 yes Figure 1 A top view of the heat sink is shown;

[0016] Figure 5 yes Figure 1 A schematic diagram of a three-dimensional structure of a substrate of a heat sink shown;

[0017] Figure 6 yes Figure 5 Schematic diagram of the three-dimensional structure of an open microchannel with embedded microneedle ribs in the substrate shown;

[0018] Figure 7 yes Figure 6 AA partial schematic diagram of the structure shown;

[0019] Figure 8 yes Figure 6 Schematic diagram of the structure of a single microchannel in the structure shown;

[0020] Fig. 9 yes Figure 5 BB cross-sectional view; DETAILED DESCRIPTION

[0021] The utility model is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The channel involved in the structure of the utility model belongs to a microchannel.

[0023] As shown in the accompanying drawings, an open microchannel heat sink 8 with embedded micro-needle fins of the utility model includes a substrate 2 and a packaging sheet 1 stacked up and down. The packaging sheet 1 and the substrate 2 are fixedly and sealedly connected to form a closed space therebetween. The fixedly and sealedly connected structure can be: if silicon is used as the substrate material, the connection method can be electrostatic bonding, and other metal materials can be sealed by gluing, screws, etc.

[0024] A fluid inlet 3 and a fluid outlet 4 are respectively provided on the packaging sheet 1 , and the fluid inlet 3 and the fluid outlet 4 are respectively connected to external cooling medium pipelines during actual use.

[0025] A groove is provided on the substrate 2 in the enclosed space, and an open microchannel 5 with embedded microneedle ribs is installed in the middle of the groove. The groove area on one side of the open microchannel 5 with embedded microneedle ribs is an inlet liquid storage tank 6 and the groove area on the other side is an outlet liquid storage tank 7.

[0026] The groove can be processed into three parts by using micro-wire cutting technology, namely, an open microchannel 5 with embedded micro-needle ribs, an inlet liquid storage tank 6 and an outlet liquid storage tank 7.

[0027] The open microchannel 5 with embedded microneedle fins includes a plurality of rib walls 10 arranged parallel to each other and spaced apart along the length direction of the substrate. A microchannel is formed between two adjacent rib walls. The microchannels are interconnected. A plurality of needle fins 11 are arranged in each microchannel and along the length direction of the substrate. The needle fins can increase the heat transfer area, enhance fluid disturbance, and strengthen the heat exchange effect. The cross section of the microchannel along the width direction of the open microchannel with embedded microneedle fins is preferably rectangular. Gaps are arranged between the top surface of the rib wall between the microchannels and the encapsulation sheet, and between the needle fin and the encapsulation sheet. The fluid inlet is sequentially connected to the inlet liquid storage tank, the open microchannel with embedded microneedle fins, the outlet liquid storage tank, and the fluid outlet.

[0028] Preferably, the fluid inlet and the inlet reservoir are arranged opposite to each other so that the fluid flows vertically into the inlet reservoir through the fluid inlet, the microchannel is arranged in the horizontal direction, and the outlet reservoir and the fluid outlet are arranged opposite to each other so that the fluid flows vertically into the fluid outlet through the outlet reservoir.

[0029] The cross section of the needle fin 11 is rhombus-shaped, and the height of the needle fin is preferably the same as the height of the rib wall, but can also be different.

[0030] After the packaging sheet 1 is bonded and packaged with the substrate 2, a microchannel heat sink is formed, and the flow path of the cooling medium is as follows: the fluid flows into the inlet reservoir 6 through the fluid inlet 3 (preferably, the fluid flows vertically through the fluid inlet 3), flows through the open microchannel 5 with embedded microneedle fins (preferably flows horizontally) and takes away the heat of the microelectronic device 9 mounted on the outer wall of the substrate from the bottom of the heat sink, cools the microelectronic device, flows to the outlet reservoir 7, and flows out of the heat sink through the fluid outlet 4 (preferably, the fluid flows vertically out of the outlet 4). Preferably, the open microchannel area with embedded microneedle fins on the substrate 2 is consistent with the area of ​​the microelectronic device to be cooled mounted on the outer wall of the substrate.

[0031] In order to improve the heat dissipation efficiency, temperature control performance and comprehensive performance of the microchannel radiator, an open microchannel with embedded micro-needle fins is used in the core part of the radiator. This microchannel structure has the following characteristics: on the one hand, unlike the closed microchannel structure, the rib wall height between the channels is equal to the channel height. In the open microchannel structure, the rib wall height between the channels is less than the channel height. Fig. 9 , which can significantly reduce the pressure drop of the microchannel radiator. At the same time, the fluids in the parallel microchannels are interconnected, which can improve the flow uniformity; on the other hand, embedding the diamond-shaped microneedle fins in the center of the microchannel can increase the heat transfer area, strengthen the fluid disturbance in the channel, and improve the heat dissipation performance of the radiator. In addition, the shape of the diamond-shaped microneedle fins is close to streamlined, avoiding excessive pressure drop and pump power consumption. Based on this, the open microchannel radiator with embedded microneedle fins combines the advantages of open microchannels and microneedle fins, which can significantly enhance the heat dissipation efficiency, temperature control performance and comprehensive performance. It is one of the effective solutions to solve the heat dissipation problem of high-power microelectronic devices.

[0032] The heat sink package sheet 1 is designed with a fluid inlet / outlet, and the cooling medium flows vertically into / out of the microchannel heat sink. According to the actual application conditions and heat dissipation requirements, new cooling mediums such as air, water, refrigerant, nanofluids, or mixed cooling mediums can be used as cooling mediums. The cooling medium undergoes single-phase convection heat exchange or phase change heat exchange in an open microchannel with embedded micro-needle fins to meet the heat dissipation requirements of micro devices of different powers and achieve good heat dissipation effect and temperature uniformity.

[0033] The microchannel heat sink substrate 2 can be made of aluminum, copper, silicon, etc., which has a thermal expansion coefficient that matches the chip. The overall shape of the heat sink (i.e., the shape of the substrate and the packaging sheet) can be rectangular, which is suitable for cooling heating surfaces such as strips and squares. The overall geometric dimensions can be determined according to the size of the device to be cooled and the overall packaging requirements.

[0034] Example:

[0035] like Figure 2 The material of the package sheet 1 is heat-resistant glass borosilicate glass, and the material of the substrate 2 is aluminum. The 100nm thick platinum metal film is closely attached to the back of the aluminum substrate by using the coating technology, and the metal film is cooled by an open microchannel heat sink with embedded micro-needle fins (simulating the heat generation of microelectronic devices). The metal film is evenly arranged in a serpentine shape, such as Figure 3. A microchannel structure with a depth of 200 μm is processed on a 3 mm thick aluminum substrate 2 by micro-wire cutting technology. The aluminum substrate is bonded to a 2 mm thick encapsulation sheet 1 to form a closed microchannel heat sink. The encapsulation sheet 1 has a fluid inlet / outlet with a diameter of 1 mm. The outer dimensions of the heat sink are 14 mm long, 2.7 mm wide, and 5 mm high. In the open microchannel 5 with embedded microneedle ribs, the microchannel is 200 μm high, while the rib wall between the microchannels is 170 μm high, and there is a 30 μm gap between the rib wall and the packaging sheet 1, which is an open microchannel; the microchannels on both sides of the 8 parallel microchannels, that is, the outer rib wall height of the first and eighth microchannels is 200 μm, thereby forming an overall closed radiator flow loop, and the channel width and the rib wall width in the channel are both 100 μm; 25 diamond-shaped central needle ribs with a height of 170 μm, a long diagonal length of 60 μm, and a short diagonal length of 40 μm are equidistantly arranged in the center of the channel, and the needle rib arrangement spacing is 340 μm, and the first microneedle rib is 130 μm away from the channel entrance, as shown in FIG. Figure 8 The open microchannel area with embedded microneedle ribs on the substrate 2 is consistent with the platinum metal film area. Water, as a cooling medium, flows vertically into the inlet liquid storage tank 6 through the fluid inlet 3, and flows horizontally through the open microchannel 5 with embedded microneedle ribs after being evenly dispersed, flows to the outlet liquid storage tank 7 after dissipating heat for the platinum metal heating film, and then flows out of the radiator through the fluid outlet 4 to achieve heat dissipation for the microelectronic device.

[0036] The platinum metal film is connected to a DC power supply to generate uniform heat to simulate the heat generation of microelectronic devices. The performance of the microchannel heat sink under different heat generation conditions was tested by adjusting the input voltage of the DC power supply. The results show that this structure can effectively improve the heat dissipation effect, significantly reduce the temperature of the bottom surface of the heat sink, significantly enhance the temperature uniformity and temperature control ability, and effectively control the pressure drop caused by the pin fins. Compared with the closed rectangular microchannel heat sink, when the thermal resistance is 1.223K / W, the pump work is reduced by 65.7%, and the energy consumption is significantly reduced; when the volume flow rate is 4.8×10 -7 m 3 / s, the performance coefficient increased by 12.3% and the overall performance was significantly improved.

Claims

1. An open microchannel heat sink with embedded micro-needle fins, comprising a substrate and a packaging sheet stacked up and down, wherein the packaging sheet and the substrate are fixedly and sealedly connected to form a closed space between the two, characterized in that: A fluid inlet and a fluid outlet are respectively provided on the encapsulation sheet, a groove is provided on the substrate in the enclosed space, an open microchannel with embedded microneedle ribs is installed in the middle of the groove, the groove area on one side of the open microchannel with embedded microneedle ribs is an inlet liquid storage tank, and the groove area on the other side is an outlet liquid storage tank, the open microchannel with embedded microneedle ribs includes a plurality of rib walls arranged parallel to each other and spaced apart along the length direction of the substrate, a microchannel is formed between two adjacent rib walls, the microchannels are connected to each other, a plurality of needle ribs are provided in each microchannel and along the length direction of the substrate, gaps are provided between the top surface of the rib walls between the microchannels and the encapsulation sheet, and between the needle ribs and the encapsulation sheet; the fluid inlet is connected to the inlet liquid storage tank, the open microchannel with embedded microneedle ribs, the outlet liquid storage tank and the fluid outlet in sequence.

2. The open microchannel heat sink with embedded micro-needle fins according to claim 1, characterized in that: The fluid inlet is arranged opposite to the inlet reservoir so that the fluid flows vertically into the inlet reservoir through the fluid inlet, the microchannel is arranged horizontally, and the outlet reservoir is arranged opposite to the fluid outlet so that the fluid flows vertically into the fluid outlet through the outlet reservoir.

3. The open microchannel heat sink with embedded micro-needle fins according to claim 1 or 2, characterized in that The substrate is made of aluminum, copper or silicon and has a thermal expansion coefficient that matches that of the chip.

4. The open microchannel heat sink with embedded micro-needle fins according to claim 1 or 2, characterized in that : The open microchannel area with embedded microneedle fins on the substrate is consistent with the area of ​​the microelectronic device to be cooled installed on the outer wall surface of the substrate.

5. The open microchannel heat sink with embedded micro-needle fins according to claim 1 or 2, characterized in that :The overall shape of the radiator is rectangular.

6. The open microchannel heat sink with embedded micro-needle fins according to claim 1 or 2, characterized in that : The microchannel cross-section along the width direction of the open microchannel of the embedded microneedle fin is rectangular.

7. The open microchannel heat sink with embedded micro-needle fins according to claim 1 or 2, characterized in that : The cross section of the needle rib is rhombus-shaped.

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