A self-adjusting cold plate structure for chip heat dissipation

Abstract

This invention discloses a self-adjusting cold plate structure for chip heat dissipation, including a cold plate body with a heat dissipation channel inside; a variable diameter assembly installed within the heat dissipation channel, comprising a transmission rod, a reset member, and an elastically deformable tubular flow guide curtain; the transmission rod is distributed along the length of the heat dissipation channel, and a slidable first sliding sleeve is fitted onto the transmission rod, with a throttling plate on the first sliding sleeve; the reset member is connected between the first sliding sleeve and the inner wall of the heat dissipation channel, and the reset direction of the reset member is opposite to the flow direction of the medium within the heat dissipation channel; the flow guide curtain is fitted onto the outside of the transmission rod, with its fixed end fixed within the heat dissipation channel and its movable end hinged to the first sliding sleeve via a pull rod. This invention can forcibly change the heat transfer mode at hot spots from heat conduction to coolant convection mixing, resulting in a qualitative breakthrough in heat dissipation efficiency at hot spots, thereby specifically solving the hot spot problem of existing chips.

Description

Technical Field

[0001] This invention belongs to the field of chip heat dissipation technology, specifically relating to a self-adjusting cold plate structure for chip heat dissipation. Background Technology

[0002] The two main technologies for chip heat dissipation are air cooling and liquid cooling, especially in the field of high-performance computing, where liquid cooling has a higher demand. Liquid cooling is divided into cold plate liquid cooling and immersion liquid cooling. Cold plate liquid cooling involves the cooling liquid flowing within a cold plate that contacts the chip, directly absorbing heat. Immersion liquid cooling submerges the entire motherboard or server in non-conductive coolant, but it suffers from high coolant costs and is not suitable for large circuit boards or situations with insufficient sealing, thus limiting its application. Therefore, the current mainstream liquid cooling method is cold plate liquid cooling.

[0003] Existing cold plate structures feature a heat dissipation channel designed inside a metal sheet (plate) for coolant flow. Additionally, the underside of the cold plate is polished to ensure proper fit with the chip casing. With the increasing demands on chip data processing capabilities in the era of intelligent technology, not only are higher processing speeds required, but also a greater variety of data types need to be processed. Current chips are typically multi-core chips, with an ever-increasing number of integrated cores. Different cores handle different tasks, resulting in a significant temperature increase in the corresponding areas of the chip casing as each core processes its respective data or task; the temperature rise is not uniform across the entire casing.

[0004] Because only a thin layer of thermal grease is applied between the chip casing and the cold plate, even though the cold plate is secured to the circuit board with multiple bolts, significant temperature differences can cause the cold plate to warp and deform, creating noticeable gaps between the cold plate and the casing. The thin layer of thermal grease is far from sufficient to fill these gaps, and when the cold plate separates from the casing in high-temperature areas, the temperature at the corresponding core area increases instead of decreasing. Current liquid cooling systems use PID control, adjusting the temperature based on the chip temperature and the circulation pump speed. While this increases the overall cooling capacity of the system, the cold plate structure cannot specifically improve heat dissipation efficiency in hot spots, meaning it cannot fundamentally solve the hot spot problem.

[0005] Furthermore, cold-plate liquid cooling suffers from the "boundary layer effect." When the coolant flows within the heat dissipation channel, due to the liquid's viscosity, liquid molecules adhering to the inner wall of the channel "stick" to the surface, reducing their velocity to zero. This stationary or nearly stationary liquid layer "drags" adjacent liquid layers, causing the liquid velocity to gradually increase from zero to the maximum velocity of the main fluid from the wall to the center of the heat dissipation channel. Because this fluid layer is almost stationary, heat transfer relies primarily on thermal conduction (lower efficiency) rather than convection mixing (higher efficiency). Therefore, a thin layer with a significant temperature gradient, known as the thermal boundary layer, forms from the high-temperature wall to the low-temperature mainstream liquid. Most existing cold-plate structures use serpentine channels to reduce the boundary layer thickness, but a noticeable boundary layer effect still exists in the straight sections of the heat dissipation channel. If the aforementioned hot spots are located at the corresponding positions on the straight sections, the hot spot problem becomes even more pronounced. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a self-adjusting cold plate structure for chip heat dissipation, comprising a cold plate body with a heat dissipation channel inside; a variable diameter assembly installed within the heat dissipation channel, the variable diameter assembly including a transmission rod, a reset member, and an elastically deformable tubular flow guide curtain; the transmission rod is distributed along the length of the heat dissipation channel, and a slidable first sliding sleeve is fitted onto the transmission rod, the first sliding sleeve being equipped with a throttling plate; the reset member is connected between the first sliding sleeve and the inner wall of the heat dissipation channel, and the reset direction of the reset member is opposite to the flow direction of the medium within the heat dissipation channel; the flow guide curtain is fitted onto the outside of the transmission rod, the fixed end of the flow guide curtain is fixed within the heat dissipation channel, and the movable end of the flow guide curtain is hinged to the first sliding sleeve via a pull rod; the flowing medium pushes the throttling plate to drive the first sliding sleeve to slide, thereby causing the pull rod to drive the movable end of the flow guide curtain to converge towards the center.

[0007] A preferred embodiment of the self-adjusting cooling plate structure in this invention is as follows: At least three tie rods are provided, all evenly distributed circumferentially. Each tie rod is hinged to the hinged end of a support rod, and the fixed end of each support rod extends along the transmission rod to the fixed end of the airflow curtain. All support rods are fixedly connected to the airflow curtain, and the airflow curtain is radially supported by the support rods. The fixed ends of all support rods and the fixed ends of the airflow curtain are fixed to the inner wall of the heat dissipation channel via ear plates, and a fixed rod is connected between each ear plate and the second sliding sleeve of the transmission rod. The transmission rod provides guidance and support for the airflow curtain's shape changes. The fixed end of the airflow curtain is fixedly connected via ear plates, and the fixed rod and the second sliding sleeve connect all ear plates to form a single unit. The transmission rod strengthens the connection structure of the fixed end, enabling the airflow curtain to cope with rapidly flowing coolant and support frequent shape changes.

[0008] A preferred embodiment of the self-regulating cold plate structure in this invention is as follows: a turbulence structure is distributed on the outer surface of the airflow guide curtain. Further, the turbulence structure is a dot-shaped protrusion or a spiral protrusion. Both the dot-shaped and spiral protrusions are boundary layers located between the airflow guide curtain and the heat dissipation channel. Both the dot-shaped and spiral protrusions break the stable liquid layer, actively creating turbulence or flow disturbance, thus solving the existing "boundary layer effect" and improving heat dissipation efficiency.

[0009] The beneficial effects of the self-adjusting cold plate structure in this invention are as follows: the variable diameter component is set at the corresponding hot spot position in the heat dissipation channel, and the temperature is controlled in the following manner under the action of PID closed-loop control: When the chip temperature is not high and no hot spot issues occur, the force of the coolant pushing the throttling plate in the heat dissipation channel is insufficient to drive the first sliding sleeve to slide. The guide curtain maintains its tubular shape. Under the tubular shape, the flow resistance is small and does not affect the flow of coolant. The circulation pump has minimal impact.

[0010] When the chip temperature rises and hot spots appear, the coolant flow rate within the heat dissipation channel increases significantly. The force pushing the throttling plate is sufficient to move the first sliding sleeve. The first sliding sleeve, via a pull rod, causes the guide curtain to deform, specifically pulling the movable end towards the center. The fixed port diameter of the upper source is larger than the movable port diameter of the lower source, forming a funnel structure. This increases the flow resistance at the center of the heat dissipation channel, causing a rapid increase in the boundary layer velocity near the inner wall of the channel. The smaller the diameter of the contracted movable end, the faster the boundary layer velocity. Compared to existing cold plate structures, this boundary layer velocity is faster, resulting in higher heat dissipation efficiency. After passing through the variable diameter assembly, the coolant flow rate returns to normal. The increased velocity is only applied at the variable diameter assembly location (i.e., the hot spot), effectively resolving the existing hot spot problem by implementing targeted velocity increases in the hot spot area. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application 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 recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the self-adjusting cold plate structure for chip heat dissipation in this invention. Figure 1 ; Figure 2 This is a schematic diagram of the self-adjusting cold plate structure for chip heat dissipation in this invention. Figure 2 ; Figure 3 for Figure 1 Internal structure diagram Figure 1 ; Figure 4 for Figure 1 Internal structure diagram Figure 2 ; Figure 5 for Figure 4 A schematic diagram showing the hidden throttling plate in the middle; Figure 6 for Figure 4 A schematic diagram showing the addition of a turbulence-inducing structure.

[0013] Reference numerals in the attached drawings: 1. Cold plate body; 2. Heat dissipation channel; 3. Transmission rod; 4. Reset component; 5. Flow guide curtain; 6. Driver; 7. First sliding sleeve; 8. Second sliding sleeve; 9. Throttling plate; 10. Pull rod; 11. Support rod; 12. Ear plate; 13. Fixing rod; 14. Turbulence structure. Detailed Implementation

[0014] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution, its implementation process, and principles will be further explained below with reference to the accompanying drawings and specific implementation examples in the embodiments of this application.

[0015] like Figures 1 to 3 As shown, this embodiment provides a self-adjusting cold plate structure for chip heat dissipation, including a cold plate body 1. The cold plate body 1 has a heat dissipation channel 2 inside, which includes straight segments and curved segments arranged in a serpentine pattern. That is, both the straight and curved segments have multiple segments. The specific number of straight and curved segments is determined by the total length of the heat dissipation channel 2. This embodiment uses seven straight segments as an example. One variable diameter component is set in one of the straight segments, but multiple variable diameter components can also be set, or one or more variable diameter components can be set in each of the multiple straight segments. The number and specific location of the variable diameter components correspond to the hot spots of the chip. This embodiment uses one variable diameter component in one straight segment as an example. The specific structure of the variable diameter component is as follows: like Figure 3 and Figure 4As shown, the variable diameter assembly includes a transmission rod 3, a reset member 4, and an elastically deformable tubular guide curtain 5. The material of the guide curtain 5 can be a high-temperature resistant elastic fabric, plastic, etc., as long as it meets the requirements of high temperature resistance (150℃) and elastic deformation. This embodiment does not impose any restrictions. The transmission rod 3 is distributed along the length direction of the heat dissipation channel 2. Specifically, one end of the transmission rod 3 extends through the side wall of the cold plate body 1, and the transmission rod 3 is slidably sealed to the cold plate body 1. That is, the transmission rod 3 and the cold plate body 1 can slide relative to each other axially. The specific position of the transmission rod 3 is controlled by the side actuator 6 of the cold plate body 1. The output end of the actuator 6 is connected to the transmission rod 3 extending out of the cold plate body 1. That is, the length of the transmission rod 3 inserted into the cold plate body 1 is determined by the actuator 6. The actuator 6 adopts a telescopic motor, and the telescopic rod of the actuator 6 drives the transmission rod 3 to move synchronously. In addition, the reset member 4 in this embodiment is a spring. The reset member 4 is sleeved on the transmission rod 3 and is close to the end where the actuator 6 is located. The reset direction of the reset member 4 is opposite to the flow direction of the medium in the heat dissipation channel 2. Specifically, the two ends of the reset component 4 are fixedly connected to the throttling vane 9 and the inner wall of the heat dissipation channel 2, respectively. When the actuator 6 pulls the transmission rod 3 outwards, the throttling vane 9 compresses the reset component 4 a certain distance, thereby increasing the initial thrust of the throttling vane 9. Conversely, when the actuator 6 pushes the transmission rod 3 inwards, the throttling vane 9 releases the reset component 4 a certain distance, thereby reducing the initial thrust of the throttling vane 9. Adjusting the initial position of the transmission rod 3 according to different heat dissipation conditions optimizes the effect of the variable diameter assembly.

[0016] like Figure 3 and Figure 5 As shown, in this embodiment, the transmission rod 3 is fitted with a slidable first sliding sleeve 7 and a second sliding sleeve 8, meaning that both the first sliding sleeve 7 and the second sliding sleeve 8 can slide axially relative to the transmission rod 3. The first sliding sleeve 7 is equipped with a throttling plate 9, which is perpendicular to the flow direction. The area of ​​the throttling plate 9 is determined according to the heat dissipation requirements, and is not limited in this embodiment.

[0017] like Figure 5As shown, in this embodiment, the flow guide curtain 5 is sleeved on the outside of the transmission rod 3. The two ends of the opening of the flow guide curtain 5 are a fixed end and a movable end, respectively. The movable end is hinged to the first sliding sleeve 7 via a pull rod 10. Specifically, there are four pull rods 10, but there can also be three, five, etc. This embodiment does not impose any restrictions, but there are at least three. All the pull rods 10 are evenly distributed along the circumference. Each pull rod 10 is hinged to the hinge end of a support rod 11, that is, the two ends of the pull rod 10 are respectively hinged to the movable end of the flow guide curtain 5 and the first sliding sleeve 7. The fixed end of each support rod 11 extends along the transmission rod 3 to the fixed end of the flow guide curtain 5. Specifically, the fixed end of each support rod 11 and the fixed end of the flow guide curtain 5 are fixed to the inner wall of the heat dissipation channel 2 via an ear plate 12, and each ear plate 12 is fixedly connected to the second sliding sleeve 8 of the transmission rod 3 via a fixed rod 13. The transmission rod 3 provides guidance and support for the changing shape of the flow guide curtain 5. The fixed end of the flow guide curtain 5 is fixedly connected through the ear plate 12, and the fixing rod 13 and the second sliding sleeve 8 connect all the ear plates 12 to form a whole. The rest of the support rod 11 is fixedly connected to the inner side of the flow guide curtain 5. Both the support rod 11 and the flow guide curtain 5 can be elastically deformed, and the flow guide curtain 5 is radially retracted through the support rod 11.

[0018] The working principle of the self-adjusting cold plate structure in this embodiment is as follows: When the chip temperature is not high and no hot spot issues occur, the circulation pump operates at low power, and the coolant flow rate in the heat dissipation channel 2 is low, insufficient to drive the throttling plate 9 to slide the first sliding sleeve 7. The support rod 11 remains straight, supporting the guide curtain 5 to maintain its tubular shape. The guide curtain 5 extends along the length of the heat dissipation channel 2, and its tubular shape results in low flow resistance, thus not affecting the flow of coolant.

[0019] When the temperature of a core component of the chip rises, the power of the circulating pump increases under PID control, the flow rate in the heat dissipation channel 2 increases, the force pushing the throttling plate 9 increases, and the throttling plate 9 and the first sliding sleeve 7 slide. The first sliding sleeve 7 drives the movable end of the support rod 11 (the end hinged to the pull rod 10 is the movable end) to retract towards the center through the pull rod 10. Each support rod 11 bends and deforms synchronously, but the fixed end of the support rod 11 remains unchanged. This causes the guide curtain 5 to change its shape from tubular to funnel-shaped, with the fixed end remaining unchanged and the movable end retracting towards the center. The fixed end of the guide curtain 5 corresponds to the hot spot of the chip. After the movable end retracts towards the center, because the throttling plate 9 is adjacent to the movable end, the throttling plate 9 acts to seal the movable end of the guide curtain 5, but it is not completely sealed off, which is referred to as "sealing". After sealing, the flow resistance of the coolant flowing through the inside of the guide curtain 5 increases significantly, which is equivalent to reducing the cross-sectional area of ​​any position of the guide curtain 5, especially the cross-sectional area at the fixed end of the guide curtain 5, where the reduction is the greatest. According to the "acceleration" mechanism of the Venturi tube, the fixed end is equivalent to the throat, where the flow velocity will increase significantly, thereby significantly improving the local heat dissipation efficiency at the corresponding hot spot location.

[0020] To further improve the local heat dissipation efficiency at hot spots, this embodiment not only increases heat dissipation efficiency by increasing the flow rate, but also overcomes the "boundary layer effect" problem. The specific structure is as follows: like Figure 6 As shown, turbulence structures 14 are distributed on the outer surface of the flow guide curtain 5. These turbulence structures 14 can be dot-like protrusions covering the entire outer surface of the flow guide curtain 5, or they can be one or more spiral protrusions. However, this embodiment is not limited to these two structures; other structures are also possible, as long as they can break the stable laminar flow. Regardless of whether the flow guide curtain 5 is in a tubular or funnel shape, the turbulence structure 14 at the fixed end of the flow guide curtain 5 is always located in the boundary layer region. Especially in the funnel shape, as the flow velocity increases, the turbulence or turbulence actively generated by the turbulence structure 14 breaks the "boundary layer effect" at and near the hot spot location, forcibly changing the heat transfer mode at the hot spot from heat conduction to coolant convection mixing. This results in a qualitative breakthrough in the heat dissipation efficiency at the hot spot, thereby specifically solving the hot spot problem of existing chips.

[0021] It should be understood that 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. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept 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 protection scope of the present invention.

Claims

1. A self-adjusting cold plate structure for chip heat dissipation, characterized in that: Includes a cold plate body (1), and a heat dissipation channel (2) is provided inside the cold plate body (1). The device includes a variable diameter assembly installed in the heat dissipation channel (2). The variable diameter assembly includes a transmission rod (3), a reset member (4), and an elastically deformable tubular flow guide curtain (5). The transmission rod (3) is distributed along the length of the heat dissipation channel (2). The transmission rod (3) is fitted with a slidable first sliding sleeve (7), and the first sliding sleeve (7) is provided with a throttling plate (9). The reset component (4) is connected between the first sliding sleeve (7) and the inner wall of the heat dissipation channel (2), and the reset direction of the reset component (4) is opposite to the flow direction of the medium in the heat dissipation channel (2); The flow guide curtain (5) is sleeved on the outside of the transmission rod (3). The fixed end of the flow guide curtain (5) is fixed in the heat dissipation channel (2), and the movable end of the flow guide curtain (5) is hinged to the first sliding sleeve (7) through the pull rod (10). The flowing medium pushes the throttling plate (9) to drive the first sliding sleeve (7) to slide, thereby causing the pull rod (10) to drive the movable end of the flow guide curtain (5) to retract towards the middle.

2. The self-adjusting cold plate structure for chip heat dissipation according to claim 1, characterized in that: The tie rod (10) has at least three rods, and all tie rods (10) are evenly distributed along the circumference.

3. The self-adjusting cold plate structure for chip heat dissipation according to claim 2, characterized in that: Each pull rod (10) is hinged to the hinge end of a support rod (11), and the fixed end of each support rod (11) extends along the transmission rod (3) to the fixed end of the flow curtain (5); all support rods (11) are fixedly connected to the flow curtain (5) and the flow curtain (5) is supported radially by the support rods (11).

4. The self-adjusting cold plate structure for chip heat dissipation according to claim 3, characterized in that: The fixed ends of all support rods (11) and the fixed ends of the guide curtain (5) are fixed to the inner wall of the heat dissipation channel (2) through ear plates (12), and a fixed rod (13) is connected between each ear plate (12) and the second sliding sleeve (8) of the transmission rod (3).

5. The self-adjusting cold plate structure for chip heat dissipation according to claim 4, characterized in that: One end of the transmission rod (3) extends through the side wall of the cold plate body (1) and the transmission rod (3) is slidably and sealed to the cold plate body (1); the side of the cold plate body (1) is provided with a driver (6), the output end of the driver (6) is connected to the transmission rod (3) extending out of the cold plate body (1), and the driver (6) drives the transmission rod (3) to move axially.

6. The self-adjusting cold plate structure for chip heat dissipation according to claim 5, characterized in that: The reset element (4) is a spring, which is sleeved on the transmission rod (3) and is located near the end of the driver (6).

7. The self-adjusting cold plate structure for chip heat dissipation according to claim 6, characterized in that: A turbulence structure (14) is distributed on the outer surface of the flow guide curtain (5).

8. The self-adjusting cold plate structure for chip heat dissipation according to claim 7, characterized in that: The turbulence structure (14) is a dot-shaped protrusion or a spiral protrusion.

9. A self-adjusting cold plate structure for chip heat dissipation according to any one of claims 1-8, characterized in that: The heat dissipation channel (2) includes straight sections and curved sections and is distributed in a serpentine pattern, with one or more variable diameter components provided along one or more straight sections.

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