Cover plate and pin fin combined type cold plate

Abstract

The invention relates to a cover plate and pin fin combined type cold plate, which belongs to the technical field of heat dissipation of electronic equipment, and comprises a cold plate main body, a refrigerant inlet, a refrigerant outlet, a static pressure cavity, cover plate pin fins, flow channels and bottom plate pin fins, the cover plate pin fins and the cold plate main body are integrally formed through a cover plate of the cold plate main body, the bottom plate pin fins and the cold plate main body are integrally formed through a bottom plate of the cold plate main body, the bottom plate pin fins are distributed at the bottom of a flow channel, the cover plate pin fins extend into the flow channel, and the cover plate pin fins and the bottom plate pin fins are distributed in a staggered mode to form a composite heat exchange structure. According to the composite cold plate with the cover plates and the pin fins, the cover plate pin fins and the bottom plate pin fins are distributed in the flow channels in a staggered mode, and a traditional one-way heat transfer path is converted into a three-dimensional networked path for jointly transferring heat to fluid; according to the structure, the effective heat exchange area is remarkably increased, and more importantly, the average distance of heat diffused from a heat source to cooling fluid is greatly shortened, so that the heat transfer efficiency is multiplied.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic devices, specifically to a composite cold plate with a cover plate and pin fins. Background Technology

[0002] As electronic components upgrade towards ultra-high integration and high power density, the heat generated per unit volume increases significantly. Heat dissipation has become a core bottleneck restricting the performance and lifespan of equipment. As a key heat dissipation component, the performance of liquid cooling plates directly affects the operational stability of electronic equipment.

[0003] However, existing liquid cooling plates face a prominent technical contradiction: in order to pursue the ultimate heat exchange performance, it is necessary to increase the density and height of the pin fins to expand the heat exchange area and enhance the convection effect. However, when processing such high-density and high-height pin fins in a single substrate (base plate), there are problems such as high processing difficulty, high cost, and even impossibility. If a split assembly is adopted, it will introduce contact thermal resistance, which will seriously offset the heat exchange benefits of the increased pin fin surface area. This is an inherent contradiction in the design of high-density pin fin heat dissipation.

[0004] In addition, existing cold plates have defects such as uneven refrigerant distribution, poor structural stability and sealing, which make it difficult to meet the heat dissipation requirements of high power density electronic components, and breakthrough technical solutions are urgently needed to solve these problems. Summary of the Invention

[0005] To address the inherent contradictions in the high-density pin-fin design of existing liquid-cooled cold plates (the conflict between the high difficulty and cost of integrated processing and the high contact thermal resistance of separate assembly), as well as technical defects such as uneven refrigerant distribution, poor structural stability, and poor sealing, the present invention aims to provide a composite cold plate with a cover plate and pin fins. Through an innovative integrated composite pin-fin structure design, without relying on a single substrate to process high-density, high-height pin fins, it avoids the contact thermal resistance problems caused by separate assembly, while achieving optimized configuration of pin fin density and height. Simultaneously, the static pressure chamber structure ensures uniform refrigerant distribution, and the sealing and fastening design improves structural stability and sealing. Ultimately, this invention overcomes existing technical bottlenecks, achieving efficient, uniform, stable, and reliable heat dissipation, meeting the extreme heat dissipation requirements of high-power-density electronic components.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a cover plate with needle fin composite cold plate.

[0007] A composite cold plate with cover plate and pin fins includes a cold plate body, a refrigerant inlet, a refrigerant outlet, a static pressure chamber, cover plate pin fins, a flow channel, and a bottom plate pin fin;

[0008] The main body of the cold plate is assembled from a cover plate and a bottom plate. The interior of the main body of the cold plate has a groove structure. The groove structure includes static pressure cavities located at the left and right ends of the interior of the main body of the cold plate and a flow channel located between the two static pressure cavities. The cover plate and the bottom plate are sealed and fastened together, so that the flow channel forms a closed channel.

[0009] The cover plate needle fins are integrally formed with the cover plate of the cold plate body and the cold plate body. The bottom plate needle fins are integrally formed with the bottom plate of the cold plate body and the cold plate body. The bottom plate needle fins are arranged at the bottom of the flow channel. When the cover plate of the cold plate body is assembled on the upper surface of the cold plate body, the cover plate needle fins extend into the flow channel and are staggered with the bottom plate needle fins to form a composite heat exchange structure.

[0010] The refrigerant inlet and the refrigerant outlet are respectively assembled at both ends of the top surface of the cold plate body, and both are connected to the static pressure cavity.

[0011] Furthermore, the cover plate and bottom plate of the cold plate body are both made of high thermal conductivity materials, which are any one of 6061 aluminum alloy, copper or oxygen-free copper.

[0012] Furthermore, the cover plate needles and the bottom plate needles are cylindrical, square, or rhomboid in shape, and the material of the cover plate needles and the bottom plate needles is the same as that of the cold plate body. The needle density of the cover plate needles and the bottom plate needles is 8-12 needles / cm².

[0013] Furthermore, the staggered arrangement of the cover plate needles and the bottom plate needles is either matrix-type misalignment or zigzag-shaped misalignment; the matrix-type misalignment refers to the array center of the cover plate needles being offset relative to the array center of the bottom plate needles along the X or Y direction; the zigzag-shaped misalignment refers to the cover plate needles being alternately offset along the length of the flow channel.

[0014] Furthermore, the horizontal staggered spacing between the cover plate needle fins and the bottom plate needle fins is 0.5-1.5 times the needle fin diameter, and the diameter of the needle fins is 1.5-2.5 mm.

[0015] Furthermore, the height of the cover plate needle fins is matched with the depth of the flow channel, with an error not exceeding ±0.1mm. After the cover plate is assembled, a gap of 0.1-0.2mm is reserved between the cover plate needle fins and the bottom of the flow channel. The gap size is 0.05-0.13 times the diameter of the needle fins.

[0016] Furthermore, the sealing and fastening connection method of the cover plate and the bottom plate of the cold plate body includes:

[0017] The upper surface of the bottom plate of the cold plate body is provided with a sealing groove, and a sealing ring is embedded in the sealing groove. The cover plate is fastened to the bottom plate of the cold plate body by bolts, and the lower surface of the cover plate is in close contact with the sealing ring.

[0018] The cover plate and the base plate are sealed together by diffusion welding or vacuum brazing, with no gaps on the welded surfaces and contact thermal resistance approaching zero.

[0019] Furthermore, both the refrigerant inlet and the refrigerant outlet are pipe joint structures. Both the refrigerant inlet and the refrigerant outlet are fixed to the top surface of the cold plate body by welding or threaded connection, and the connection with the static pressure cavity adopts a flared transition structure with a flared transition angle of 45°-60°.

[0020] Furthermore, the two static pressure chambers are an inlet static pressure chamber and an outlet static pressure chamber, respectively, with a trapezoidal or arc-shaped cross-section. The width-to-depth ratio of the static pressure chambers is 1:6. The inlet static pressure chamber is connected to the refrigerant inlet, and the outlet static pressure chamber is connected to the refrigerant outlet.

[0021] Furthermore, when the static pressure cavity has a trapezoidal cross-section, its upper base width is 15-25mm and its lower base width is 10-18mm; when the static pressure cavity has an arc-shaped cross-section, its radius of curvature is 10-15mm.

[0022] Compared with the prior art, the present invention provides a cover plate with needle fin composite cold plate, which has the following beneficial effects:

[0023] 1. The cover plate with needle-fin composite cold plate has a composite needle-fin structure consisting of base plate needle fins and cover plate needle fins. The two are integrally formed with the base plate and cover plate of the cold plate body, respectively. This design fundamentally avoids the processing cost and feasibility problems caused by directly processing high-density and high-difficulty needle fins on a single substrate (base plate) in pursuit of high heat exchange area. At the same time, the integrated molding process completely eliminates the contact thermal resistance that is inevitably introduced by the separate assembly of needle fins, and solves the contradiction between "difficult processing" and "high thermal resistance" in the design of high-density needle fins.

[0024] 2. The cover plate with a needle-fin composite cold plate, through the staggered distribution of the cover plate needle fins and the base plate needle fins in the flow channel, transforms the traditional unidirectional heat transfer path of "base plate → needle fins → fluid" into a three-dimensional network path of "base plate → base plate needle fins" and "cover plate → cover plate needle fins" for heat transfer to the fluid. This structure not only significantly increases the effective heat exchange area, but more importantly, it greatly shortens the average distance of heat diffusion from the heat source (chip) to the cooling fluid, thereby multiplying the heat transfer efficiency, and is especially suitable for handling ultra-high heat flux density.

[0025] 3. The cover plate is equipped with a needle-fin composite cold plate, which forms a complex three-dimensional turbulence structure through the staggered composite needle fins. When the refrigerant flows through it, the flow direction is continuously changed, which effectively destroys the thermal boundary layer and forces the fluid to change from laminar or transitional flow to a highly turbulent state. The strong lateral mixing and longitudinal disturbance greatly enhance the convective heat transfer coefficient and avoid the appearance of "dead water zone" in the flow channel, ensuring the temperature uniformity of the entire heat dissipation surface.

[0026] 4. The cover plate is equipped with a needle-fin composite cold plate. Through the static pressure cavities set at both ends inside the cold plate body, the cross-section is optimized (such as trapezoidal or arc shape) and has a reasonable width-to-depth ratio. It can effectively distribute the refrigerant evenly from the inlet to the entire width of the flow channel and gently collect it at the outlet. It can ensure the uniformity of the flow field and temperature field from the source and improve the reliability of heat dissipation performance. At the same time, through precise sealing and fastening connection (such as vacuum brazing or sealing ring bolt connection), it ensures the long-term sealing reliability of the flow channel under high working pressure and the structure is stable.

[0027] 5. This cover plate with a pin-fin composite cold plate, through optimized design of key parameters such as staggered spacing (0.5-1.5 times the pin diameter) and bottom gap of the cover plate pin fins (0.1-0.2mm), can significantly improve heat exchange efficiency (thermal resistance reduced by more than 39.3%) and heat dissipation uniformity (chip surface temperature difference reduced by more than 74.5%), while only increasing flow resistance by 16.7% and not causing a significant increase in system pump power. It achieves an optimized balance between heat dissipation performance, uniformity and system energy consumption, takes into account the system's energy efficiency ratio, and has excellent engineering application value. Attached Figure Description

[0028] Figure 1 This is a perspective view of a cover plate with needle-fin composite cold plate according to the present invention;

[0029] Figure 2 This is a bottom view of the cover plate needle fins of a composite cold plate with a cover plate and needle fins according to the present invention.

[0030] Figure 3 This is a top view of the bottom plate needle fins of a cover plate with needle fins composite cold plate according to the present invention;

[0031] Figure 4 This is a schematic diagram showing the arrangement of the cover plate needles and the bottom plate needles in a composite cold plate with a cover plate and needles according to the present invention.

[0032] In the diagram: 1. Cold plate body; 2. Refrigerant inlet; 3. Refrigerant outlet; 4. Static pressure chamber; 5. Cover plate pin fins; 6. Flow channel; 7. Base plate pin fins. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figures 1 to 4 In this embodiment, a cover plate with pin fin composite cold plate has an overall projected size of 140 mm (length) × 100 mm (width) and a total thickness of 18 mm to accommodate compact electronic equipment installation space. Both the cold plate body 1 and the cover plate are made of 6061 aluminum alloy with excellent thermal conductivity and good machinability, and its thermal conductivity is not less than 180 W / (m·K), ensuring that heat can be quickly dissipated from the heat source.

[0035] In this embodiment, the flow channel 6 and the static pressure chamber 4 are:

[0036] A groove structure is machined inside the main body 1 of the cold plate. Along its length, a static pressure chamber 4 is set at each end, each chamber being 25 mm long. The middle section is a flow channel 6, with an effective length of 90 mm, a width of 100 mm (the same as the cold plate), and a depth of 10 mm, providing ample space for the needle-fin layout and fluid flow. The cross-section of the static pressure chamber 4 adopts an arc-shaped design with a radius of curvature of 12 mm and a width-to-depth ratio of approximately 1.8 to achieve stable and uniform distribution and collection of the refrigerant.

[0037] The needle-wing parameters and composite structure in this embodiment are as follows:

[0038] Basic parameters of the needle fins: The needle fins are cylindrical. The diameter of the cover plate needle fin 5 and the bottom plate needle fin 7 is 2.0 mm, and the height is 10.0 mm. The needle fin density is set to 10 fins / cm².

[0039] Quantity and layout: The effective area of ​​the flow channel is 90 cm², therefore, 450 needles are arranged on the cover plate and 450 needles on the bottom plate, for a total of 900 needles. The bottom plate needles 7 are integrally formed with the bottom plate of the cold plate body 1 at the bottom of the flow channel; the cover plate needles (5) are integrally formed with the cover plate of the cold plate body 1.

[0040] Staggered arrangement: A matrix-style staggered arrangement is adopted. The center of the cover plate needle fin array is precisely offset by 1.0 mm along the flow channel width direction (X direction) relative to the center of the bottom plate needle fin array. This value is 0.5 times the needle fin diameter and is within the optimal staggered spacing range (0.5-1.5 times the diameter). The horizontal center distance between the needle fins is 2.0 mm.

[0041] Key gap control: The matching error between the design height (10.0 mm) of the cover plate pin fin 5 and the flow channel depth (10 mm) is controlled within +0.05 mm. After the cover plate is vacuum brazed and sealed to the cold plate body, a micro gap of approximately 0.15 mm is formed between the end of the cover plate pin fin and the bottom of the flow channel 6. This gap prevents "heat transfer short circuit" caused by direct contact between the pin fins and ensures that the fluid at this point still maintains a certain flow velocity, effectively flushing the bottom plate surface and avoiding the formation of local hot spots.

[0042] Interface and seal in this embodiment:

[0043] The refrigerant inlet 2 and refrigerant outlet 3 use G1 / 2 specification pipe fittings, which are fixed to the corresponding static pressure chamber on the side wall of the cold plate body by argon arc welding. The connection is designed with a 50° flared transition structure to reduce local flow resistance.

[0044] The cover plate and base plate of the cold plate body 1 are sealed together using a vacuum brazing process. This process creates a metallurgical bond between the two, resulting in near-zero contact thermal resistance and extremely high structural strength and sealing performance. After welding, a 1.0 MPa pressure test was conducted, and no leakage was observed after 30 minutes of pressure holding, meeting the requirements for high reliability.

[0045] Performance verification and comparison in this embodiment:

[0046] To quantify the heat dissipation performance of this embodiment, a conventional single-sided finned heat exchanger with the same projected area (140mm × 100mm) was selected as a comparison benchmark. This conventional heat exchanger only has 450 fins (2.0mm × 10mm) of the same diameter and height at the bottom of the flow channel. Under the same test conditions (inlet liquid temperature 30℃, flow rate 5 L / min, system pump power approximately 20 W, chip heat flux density 300 W / cm²), the experimental results show that:

[0047] Total thermal resistance: The cold plate of this invention has a thermal resistance of 0.068 ℃·cm² / W, which is 39.3% lower than that of the traditional cold plate of 0.112 ℃·cm² / W.

[0048] Heat dissipation uniformity: The maximum temperature difference on the chip surface is only 3.8 ℃ in the cold plate of this invention, which is much lower than the 14.9 ℃ of the traditional cold plate, and the uniformity is improved by 74.5%.

[0049] Convection heat transfer coefficient: The cold plate of this invention reaches 7350 W / (m²·℃), which is 71.7% higher than that of the traditional cold plate of 4280 W / (m²·℃).

[0050] Flow resistance: The cold plate of this invention has a flow resistance of 9.8 kPa, which is only 16.7% higher than the traditional cold plate's 8.4 kPa, and the increase in system energy consumption is controllable.

[0051] The working principle of the above embodiments is as follows:

[0052] The heat flow path of a traditional liquid-cooled cold plate is a unidirectional path of "base plate → pin fins → fluid," resulting in a long heat diffusion distance and limited heat transfer efficiency. In this invention, the cover plate pin fins 5 and the base plate pin fins 7 are arranged alternately, fundamentally changing the heat flow path and forming a networked path of "base plate → base plate pin fins 7 ║ cover plate → cover plate pin fins 5" for three-dimensional heat transfer to the fluid. This path significantly shortens the heat diffusion distance: part of the heat absorbed by the electronic components in the cold plate body 1 is directly transferred to the fluid through the base plate pin fins 7, and the other part is conducted through the cover plate to the cover plate pin fins 5 and then transferred to the fluid. The bidirectional heat transfer network significantly improves the heat transfer efficiency and results in a more uniform heat distribution.

[0053] The staggered distribution of the cover plate and base plate needles in the fluid dynamics mechanism constitutes a complex three-dimensional turbulence structure. When the refrigerant flows through channel 6, the staggered needles continuously disrupt the thermal boundary layer formed by the fluid: the fluid, which was originally in a laminar or transitional flow state along the channel, undergoes continuous changes in flow direction under the action of the three-dimensional turbulence structure, forming strong lateral mixing and longitudinal disturbance, and ultimately being forced into a highly turbulent state. In the turbulent state, the heat transfer rate inside the fluid is greatly improved, while avoiding the formation of dead zones due to local stagnation of fluid in the channel, further enhancing the convective heat transfer effect and ensuring uniform heat dissipation.

[0054] In summary, this specific embodiment fully demonstrates the technical advantages of the composite cold plate with pin fins attached to the cover plate of the present invention. Through the comprehensive application of technologies such as integrated composite pin fin design, three-dimensional staggered layout, parameterized gap control, and uniform distribution of static pressure cavity, this cold plate successfully achieves efficient (significantly reduced thermal resistance), uniform (largely reduced temperature difference), and low-power (limited increase in resistance) heat dissipation under an extreme heat load of 300 W / cm², perfectly meeting the extreme heat dissipation requirements of high-power-density electronic components.

[0055] The installation, connection, or setting methods disclosed in this embodiment are all common mechanical connection methods. Any method that can achieve its beneficial effect can be implemented. In addition, the electrical components in this embodiment are all electrically connected to the main controller and the power supply. The main controller can be a conventional known device such as a computer that plays a control role. Those skilled in the art can control the electrical components through simple programming. Moreover, the existing disclosed power connection technology is also common knowledge in the field. Therefore, the control method and circuit connection will not be explained in detail in this embodiment.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite cold plate with a cover plate and pin fins, characterized in that: It includes the main body of the cold plate (1), refrigerant inlet (2), refrigerant outlet (3), static pressure chamber (4), cover plate pin fins (5), flow channel (6), and bottom plate pin fins (7); The main body of the cold plate (1) is formed by splicing a cover plate and a bottom plate. The interior of the main body of the cold plate (1) is provided with a groove structure. The groove structure includes static pressure chambers (4) located at the left and right ends inside the main body of the cold plate (1) and a flow channel (6) located between the two static pressure chambers (4). The cover plate is sealed and fastened to the bottom plate, so that the flow channel (6) forms a closed channel. The cover plate needle fins (5) are integrally formed with the cover plate of the cold plate body (1) and the cold plate body (1). The bottom plate needle fins (7) are integrally formed with the bottom plate of the cold plate body (1). The bottom plate needle fins (7) are arranged at the bottom of the flow channel (6). When the cover plate of the cold plate body (1) is assembled on the upper surface of the cold plate body (1), the cover plate needle fins (5) extend into the flow channel (6) and are staggered with the bottom plate needle fins (7) to form a composite heat exchange structure. The refrigerant inlet (2) and the refrigerant outlet (3) are respectively assembled at both ends of the top surface of the cold plate body (1), and both are connected to the static pressure chamber (4).

2. The cover plate with pin fin composite cold plate according to claim 1, characterized in that: The cover plate and bottom plate of the cold plate body (1) are both made of high thermal conductivity material, which is any one of 6061 aluminum alloy, copper or oxygen-free copper.

3. The cover plate with pin fin composite cold plate according to claim 1, characterized in that: The cover plate needle fins (5) and the bottom plate needle fins (7) are cylindrical, square or rhomboid in shape. The material of the cover plate needle fins (5) and the bottom plate needle fins (7) is the same as that of the cold plate body (1). The needle fin density of the cover plate needle fins (5) and the bottom plate needle fins (7) is 8-12 needles / cm².

4. The cover plate with pin fin composite cold plate according to claim 1, characterized in that: The staggered arrangement of the cover plate needles (5) and the bottom plate needles (7) is either matrix-type staggered or zigzag-shaped staggered; the matrix-type staggered means that the array center of the cover plate needles (5) is offset relative to the array center of the bottom plate needles (7) along the X or Y direction; the zigzag-shaped staggered means that the cover plate needles (5) are alternately offset along the length of the flow channel.

5. A composite cold plate with pin fins attached to a cover plate according to claim 1, characterized in that: The horizontal staggered spacing between the cover plate needle fins (5) and the bottom plate needle fins (7) is 0.5-1.5 times the diameter of the needle fins, and the diameter of the needle fins is 1.5-2.5 mm.

6. A composite cold-rolled plate with pin fins as described in claim 1, characterized in that: The height of the cover plate needle fin (5) matches the depth of the flow channel (6) with an error not exceeding ±0.1mm. After the cover plate is assembled, a gap of 0.1-0.2mm is reserved between the cover plate needle fin (5) and the bottom of the flow channel (6). The gap size is 0.05-0.13 times the diameter of the needle fin.

7. A cover plate with pin fin composite cold plate according to claim 1, characterized in that, The sealing and fastening connection methods of the cover plate and bottom plate of the cold plate body (1) include: The upper surface of the bottom plate of the cold plate body (1) is provided with a sealing groove, and a sealing ring is embedded in the sealing groove. The cover plate is fastened to the bottom plate of the cold plate body (1) by bolts, and the lower surface of the cover plate is tightly fitted with the sealing ring. The cover plate and the base plate are sealed together by diffusion welding or vacuum brazing, with no gaps on the welded surfaces and contact thermal resistance approaching zero.

8. A composite cold-rolled plate with pin fins as described in claim 1, characterized in that: The refrigerant inlet (2) and refrigerant outlet (3) are both pipe joint structures. The refrigerant inlet (2) and refrigerant outlet (3) are fixed to the top surface of the cold plate body (1) by welding or threaded connection. The connection with the static pressure chamber (4) adopts a flared transition structure with a flared transition angle of 45°-60°.

9. A composite cold plate with pin fins attached to a cover plate according to claim 1, characterized in that: The two static pressure chambers (4) are the inlet static pressure chamber and the outlet static pressure chamber, respectively. The cross-sectional shape is trapezoidal or arc-shaped. The width-to-depth ratio of the static pressure chamber (4) is 1:

6. The inlet static pressure chamber is connected to the refrigerant inlet (2), and the outlet static pressure chamber is connected to the refrigerant outlet (3).

10. A cover plate with pin fin composite cold plate according to claim 9, characterized in that: When the static pressure cavity (4) has a trapezoidal cross section, its upper base width is 15-25mm and its lower base width is 10-18mm; when the static pressure cavity (4) has an arc-shaped cross section, its radius of curvature is 10-15mm.

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