Chip heat dissipation system and heat dissipation method based on deformed phase change capsule

Abstract

The invention relates to the field of chip heat dissipation systems, in particular to a chip heat dissipation system and a chip heat dissipation method.The chip heat dissipation system comprises a liquid pump, a built-in heat exchanger and an external heat exchanger, cooling liquid contains the phase change capsule, the built-in heat exchanger comprises a radiator substrate and a capsule capture array, and the capsule capture array is arranged on the radiator substrate. The heat radiator substrate is attached to the heating surface of the chip, a cooling liquid flow channel is formed in the heat radiator substrate, the capsule capturing array is used for capturing the phase change capsule at the heating part of the chip so as to enhance heat radiation, the phase change capsule has an initial solid sphere shape, and the phase change capsule rotates in a spiral channel of the external heat exchanger in a non-directional mode so as to recover the initial shape. According to the embodiment of the invention, the phase change capsule is captured by using the deformation of the shape memory alloy, and the phase change capsule is separated from the capture by using the deformation of the phase change capsule, so that the phase change capsule is efficiently gathered in the overheating area of the chip for fixed-point cooling, and the problem of low efficiency of non-differential cooling of the non-uniform overheating area by traditional water cooling is solved.

Description

Technical Field

[0001] The present invention relates to the field of chip heat dissipation systems, and particularly to a chip heat dissipation system based on deformable phase change capsules.

[0002] The present invention also relates to a chip heat dissipation method based on deformable phase change capsules. Background Art

[0003] Two different regions of the same integrated circuit chip may dissipate different thermal powers during operation, resulting in local overheating. In this case, when the water cooling device can sufficiently cool the hottest region of the chip, the cooling effect of the coldest region of the chip exceeds the necessary level, leading to unnecessary power consumption of the pump for circulating the coolant in the device. Summary of the Invention

[0004] The purpose of the present invention is to provide a chip heat dissipation system and a heat dissipation method based on deformable phase change capsules, which aim to utilize the dual deformation effects of shape memory alloys and phase change capsules to capture and release phase change capsules in the overheated regions of the chip, thereby solving the inefficient problem of the traditional water cooling for non-uniform overheated regions without discrimination.

[0005] To solve the above technical problems, the present invention specifically provides the following technical solutions: A chip heat dissipation system based on deformable phase change capsules, comprising an internal heat exchanger and an external heat exchanger connected by a liquid pump, and the liquid pump circulates a coolant containing phase change capsules between the internal heat exchanger and the external heat exchanger; The phase change capsules have an initial solid spherical form; The internal heat exchanger includes a radiator substrate and a capsule capture array. The radiator substrate is attached to the heat generating surface of the chip, and a coolant flow channel is formed inside it. The capsule capture array is arranged on one side of the coolant flow channel close to the heat generating surface of the chip. The capsule capture array includes at least one capture member made of shape memory alloy material, and the capture member is configured to: when its temperature is greater than a first threshold, deform into a shape capable of capturing the phase change capsules in the solid spherical form; when its temperature is less than a second threshold, deform into a shape incapable of capturing the phase change capsules in the solid spherical form; The external heat exchanger includes a plurality of parallel spiral channels, and micro inclined fins for contacting with the phase change capsules and forcing them to rotate and / or change their rotation directions are formed inside the spiral channels to promote the cooling of the phase change capsules and their recovery to the solid spherical form.

[0006] Further, the cross-sectional shape of the spiral channel is rectangular, and an inflow pipe tangent to the spiral channel is connected to the inlet of the spiral channel.

[0007] Furthermore, heat dissipation fins are integrated on the outer wall of the spiral channel, and the external heat exchanger further includes a fan for guiding external air to perform convective heat exchange with the spiral channel.

[0008] Furthermore, the capsule capture array includes a plurality of the capture members distributed in a rectangular array, and each capture member corresponds to a local heat dissipation area on the chip.

[0009] Furthermore, the capture member includes a fixed end and a movable end. The fixed end is embedded in the radiator substrate, one end of the movable end is suspended above the bottom wall of the coolant flow channel, and a groove for accommodating the phase change capsule is formed between the movable end and the bottom wall of the coolant flow channel.

[0010] Furthermore, it is characterized in that: The movable end includes a U-shaped or gate-shaped structure formed by two side bars and a cross bar.

[0011] Furthermore, it is characterized in that: When the temperature of the capture member is greater than the first threshold, the capture member is in the austenite state, and the distance between the cross bar of the movable end and the bottom wall of the coolant flow channel is less than the diameter of the phase change capsule in the solid sphere form, so that the phase change capsule is constrained in the groove by the side bars and the cross bar. After the phase change capsule absorbs heat and undergoes a phase change and changes its shape, it can be extruded from the gap between the cross bar and the bottom wall of the coolant flow channel; When the temperature of the capture member is less than the second threshold, the capture member is in the martensite state, and the distance between the cross bar of the movable end and the bottom wall of the coolant flow channel is greater than the diameter of the phase change capsule in the solid sphere form, so that the phase change capsule cannot be captured.

[0012] Furthermore, the phase change capsule includes a core and a shell. The core is a paraffin-based phase change material, and the shell includes a flexible inner layer and a wear-resistant outer layer.

[0013] A chip heat dissipation method based on a deformable phase change capsule uses a chip heat dissipation system. The chip heat dissipation method includes the following steps: Start the liquid pump to circulate the coolant containing the phase change capsule between the built-in heat exchanger and the external heat exchanger; When the temperature of a local area of the chip rises, causing the temperature of the capture member in the corresponding area of the built-in heat exchanger to exceed the first threshold, the capture member deforms and captures the phase change capsule in the solid sphere form flowing through there; When the temperature of the local area of the chip drops, causing the temperature of the capture member to be lower than the second threshold, the capture member resumes its shape and no longer captures the phase change capsule; The captured phase change capsules absorb heat and undergo phase change, and their shape changes and they detach from the capturing element. The coolant carrying the phase change capsules after the phase change flows into the external heat exchanger, where the phase change capsules are cooled and restored to the solid spherical form.

[0014] Furthermore, the phase change capsule contacts the inner wall of the spiral channel of the external heat exchanger under the action of centrifugal force, and is rotated in an undirected manner due to the movement of the micro-inclined fins inside the spiral channel, while heat is dissipated through the coolant and the spiral channel wall until the phase change capsule returns to the solid spherical form.

[0015] Compared with the prior art, this application has the following beneficial effects: The embodiments of the present invention utilize the deformation of shape memory alloys to capture phase change capsules, and utilize the deformation of phase change capsules to release the capture, so that the phase change capsules are efficiently gathered in the overheated area of ​​the chip for fixed-point cooling, thereby solving the inefficient problem of traditional water cooling indiscriminately cooling non-uniform overheated areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0017] Figure 1 is a system diagram of an embodiment of the present invention; Figure 2 is a three-dimensional diagram of a heat sink substrate according to an embodiment of the present invention; Figure 3 is a three-dimensional diagram of a capsule capture array according to an embodiment of the present invention; Figure 4 A front view of a spiral channel according to an embodiment of the present invention; Figure 5 It is a front view of a built-in heat exchanger according to an embodiment of the present invention; Figure 6 for Figure 5 Cross-sectional view in the AA direction; Figure 7 for Figure 5 Cross-sectional view in the BB direction; Figure 8 A schematic diagram of the process of passing, capturing and detaching a phase change capsule according to an embodiment of the present invention; The numbers in the figure represent the following: 1 - Chip; 2 - Built-in heat exchanger; 21 - Heat sink substrate; 211 - Coolant flow channel; 22 - Capsule capture array; 221 - Capture member; 222 - Fixed end; 223 - Movable end; 224 - Side bar; 225 - Cross bar; 226 - Groove; 3 - External heat exchanger; 31 - Spiral channel; 32 - Heat dissipation fins; 33 - Micro inclined fins; 4 - Liquid pump; 5 - Phase change capsule. Detailed implementation manners

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Two different regions of the same integrated circuit chip 1 may dissipate different thermal powers during operation, thus resulting in local overheating. In this case, when the water cooling device can sufficiently cool the hottest region of the chip 1, the cooling effect of the coldest region of the chip 1 exceeds the necessary degree, thereby causing unnecessary power consumption of the pump for circulating the coolant in the device.

[0020] To solve this problem, this case proposes a chip heat dissipation system based on deformable phase change capsules, hereinafter referred to as the chip heat dissipation system, which can perform fixed-point enhanced cooling on the overheated region of the chip 1, thereby achieving temperature balance in each region of the chip 1.

[0021] The core method adopted by the chip heat dissipation system is: using a coolant containing the phase change capsule 5 to perform liquid cooling on the chip 1. The initial shape of the phase change capsule 5 is a solid sphere. A capsule catcher is arranged in the coolant flow channel 211 of the heat sink substrate 21 of the chip 1. The capsule catcher fixes the phase change capsule 5 in the overheated region of the chip 1, thereby achieving local enhanced cooling of the chip 1. After phase change, the shape of the phase change capsule 5 changes, thus breaking free from the restraint of the capsule catcher and returning to a solid sphere during the reflux process.

[0022] Specifically, referring to Figure 1 , the chip heat dissipation system includes: a built-in heat exchanger 2, an external heat exchanger 3, and a liquid pump 4. The liquid pump 4 is used to circulate the coolant containing the phase change capsule 5 between the built-in heat exchanger 2 and the external heat exchanger 3. The initial form of the phase change capsule 5 is a solid sphere. The phase change capsule 5 has the function of absorbing heat during phase change and can be suspended in the coolant.

[0023] Among them, the built-in heat exchanger 2 includes a heat sink substrate 21 and a capsule capture array 22.

[0024] Referring to Figure 2The heat sink substrate 21 is used to fit the heat generating surface of the chip 1 , and a cooling liquid flow channel 211 is formed inside. The capsule capture array 22 is arranged on a side of the cooling liquid flow channel 211 close to the chip 1 .

[0025] refer to Figure 3 The capsule capture array 22 includes a plurality of capture elements 221 distributed along a rectangular array. When the temperature of the capture element 221 is greater than a first threshold, the capture element 221 is deformed into a shape of a phase change capsule 5 that can capture a solid sphere. When the temperature of the capture element 221 is less than a second threshold, the capture element 221 is deformed into a shape of a phase change capsule 5 that cannot capture a solid sphere.

[0026] refer to Figure 4 The external heat exchanger 3 includes a plurality of parallel spiral channels 31, and the interior of the spiral channel 31 is formed with micro-inclined fins 33 with irregular inclination directions. The phase change capsule 5 moves in a spiral manner in the spiral channel 31, and contacts the inner wall of the spiral channel 31 under the action of centrifugal force. When the micro-inclined fins 33 contact the phase change capsule 5, they move the phase change capsule 5, forcing the phase change capsule 5 to rotate, or change the rotation direction of the phase change capsule 5, so that the phase change capsule 5 rotates and cools in an undirected manner inside the spiral channel 31, so that the irregular flexible particle shape is restored to a solid sphere before leaving the spiral channel 31.

[0027] The cross-sectional shape of the spiral channel 31 can be circular, semicircular or rectangular. Preferably, the cross-sectional shape of the spiral channel 31 is rectangular, and the inlet of the spiral channel 31 is connected to an inlet tube tangent to the spiral channel 31, thereby enhancing the centrifugal movement of the phase change capsule 5 when it enters the spiral channel 31 with the coolant.

[0028] Preferably, the outer wall of each spiral channel 31 is integrated with heat dissipation fins 32, and the external heat exchanger 3 also includes a fan for guiding convection between the outside air and the outer wall of the spiral channel 31 and the heat dissipation fins 32, and the heat dissipation fins 32 and the fan are not shown in the figure.

[0029] Preferably, the coolant is deionized water, and the liquid pump 4 is a type that can stably transport the fluid containing the phase change capsules 5, such as a centrifugal pump with low shear force.

[0030] Preferably, reference Figure 5 , Figure 6 and Figure 7 Each capture element 221 corresponds to a local heat dissipation area. The local heat dissipation area refers to the contact area between the chip 1 and the radiator substrate 21, which corresponds to the part of the heat-generating core inside the chip 1. These local heat dissipation areas are usually distributed in a rectangular array, thereby corresponding to the layout of the heat-generating core inside the chip 1.

[0031] Preferably, reference Figure 8, the material of the capturing member 221 is nickel-titanium shape memory alloy. The structure of the capturing member 221 includes a fixed end 222 and a movable end 223 arranged sequentially along the flow direction of the coolant. The fixed end 222 is embedded in the position of the radiator substrate 21 close to the heat source of the chip 1, so as to ensure rapid thermal response. The movable end 223 is suspended above the radiator substrate 21, so as to perform the action of capturing the phase change capsule 5.

[0032] The movable end 223 includes two parallel side bars 224 and a cross bar 225, thus forming a U-shaped or gate-shaped structure. The side of the movable end 223 facing the oncoming flow direction and the radiator substrate 21 form a groove 226 that fits the phase change capsule 5 in the shape of a solid sphere. The surface of the cross bar 225 contacting the phase change capsule 5 can be designed as an arc or an obtuse angle.

[0033] When the temperature of the capturing member 221 is greater than the first threshold, the capturing member 221 is in the austenite state. The distance between the cross bar 225 and the bottom wall of the coolant flow channel 211 is less than the diameter of the phase change capsule 5. After the phase change capsule 5 impacts the inside of the groove 226, the side bars 224 limit the left and right movement of the phase change capsule 5, and the cross bar 225 and the bottom wall limit the up and down movement of the phase change capsule 5, realizing reliable capture until the phase change capsule 5 generates a liquefaction phase change and then changes its own shape and extrudes from the gap between the top of the movable part and the bottom wall of the coolant flow channel 211.

[0034] When the temperature of the capturing member 221 is less than the second threshold, the capturing member 221 is in the martensite state. The distance between the top of the movable part and the bottom wall of the coolant flow channel 211 is greater than the diameter of the phase change capsule 5. After the phase change capsule 5 impacts the inside of the groove 226, the phase change capsule 5 flows away from the gap between the cross bar 225 and the coolant flow channel 211.

[0035] The core of the phase change capsule 5 uses RT65 paraffin-based phase change material (phase change temperature about 65 °C). The outer shell includes a double-layer structure. The inner layer is polyurethane with better flexibility, which is used to adapt to the phase change volume change of the core. The outer layer is a harder and more wear-resistant polyurea or modified melamine resin, with a thickness of about 15 - 25 microns, which is used to provide mechanical strength and wear resistance. The diameter range of the phase change capsule 5 is 0.7 - 0.9 mm. Initially, it is a solid sphere, and after liquefaction, it becomes an irregular and flexible droplet.

[0036] The cooling method adopted by the chip cooling system is: Startup and normal cycle: The liquid pump 4 starts, driving the coolant containing the phase change capsule 5 to circulate in the system. When flowing through the built-in heat exchanger 2, the coolant and the phase change capsule 5 absorb the heat generated by the chip 1. When flowing through the external heat exchanger 3, the coolant and the phase change capsule 5 that have not undergone a phase change are cooled.

[0037] Overheating forms and captures phase change capsules 5: When the temperature of a certain area of ​​the chip 1 rises, the temperature of the corresponding capture element 221 exceeds T1 (70°C) through conduction from the substrate, and the capture element 221 deforms, capturing the solid phase change capsules 5 flowing through here and fixing them on the bottom wall of the flow channel in the hot spot area.

[0038] Heat absorption and detachment of the phase change capsule 5: The captured phase change capsule 5 directly absorbs a large amount of heat from the high-temperature bottom wall, the internal paraffin melts (about 65°C), the shape of the phase change capsule 5 changes, and it can be deformed and squeezed out from the gap between the capture piece 221 and the bottom wall under the action of the flow of coolant.

[0039] Overheating relief and release of the phase change capsule 5: Due to the phase change heat absorption of the phase change capsule 5, the hot spot temperature of the chip 1 decreases. When the temperature is lower than T2 (60°C), the capture element 221 returns to the cold state and no longer captures the phase change capsule 5.

[0040] Regeneration and shape restoration of the phase change capsule 5: the coolant carrying the liquefied phase change capsule 5 enters the external heat exchanger 3, and is continuously stirred by the inclined micro-fins in the spiral channel 31, causing the liquefied phase change capsule 5 to tumble and rotate in an undirected and continuous manner. At the same time, the heat of the phase change capsule 5 is transferred to the spiral channel 31 through the coolant, and dissipated through forced convection with the outside air. During the rotation and cooling process, the paraffin inside the phase change capsule 5 is evenly cooled and re-solidified, causing the phase change capsule 5 to restore to a solid spherical shape. The phase change capsule 5 restored to a solid spherical shape leaves the external heat exchanger 3 along with the coolant.

[0041] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A chip cooling system based on deformable phase change capsules, characterized in that: It comprises an internal heat exchanger (2) and an external heat exchanger (3) connected by a liquid pump (4), wherein the liquid pump (4) circulates a cooling liquid containing phase change capsules (5) between the internal heat exchanger (2) and the external heat exchanger (3); The phase-change capsule (5) has an initial solid spherical morphology; The built-in heat exchanger (2) comprises a heat sink substrate (21) and a capsule capture array (22); the heat sink substrate (21) is attached to the heating surface of the chip (1) and has a coolant flow channel (211) formed therein; the capsule capture array (22) is arranged on a side of the coolant flow channel (211) close to the heating surface of the chip (1); the capsule capture array (22) comprises at least one capture element (221); the capture element (221) is made of a shape memory alloy material; the capture element (221) is configured such that: when its temperature is greater than a first threshold value, it is deformed into a shape capable of capturing the phase change capsule (5) in the solid spherical form; and when its temperature is less than a second threshold value, it is deformed into a shape unable to capture the phase change capsule (5) in the solid spherical form; The external heat exchanger (3) comprises a plurality of parallel spiral channels (31), wherein micro-inclined fins (33) are formed inside the spiral channels (31) for contacting the phase change capsule (5) and forcing it to rotate and / or change its rotation direction, so as to promote cooling of the phase change capsule (5) and restore it to the solid spherical form.

2. The chip cooling system based on deformable phase change capsules according to claim 1 is characterized in that: The cross-section of the spiral channel (31) is in the shape of a rectangle, and the inlet of the spiral channel (31) is connected to an inlet pipe tangent to the spiral channel (31).

3. The chip cooling system based on deformable phase change capsules according to claim 1 is characterized in that: The outer wall of the spiral channel (31) is integrated with heat dissipation fins (32), and the external heat exchanger (3) further comprises a fan for guiding external air to perform convective heat exchange with the spiral channel (31).

4. The chip cooling system based on deformable phase change capsules according to claim 2 is characterized in that: The capsule capture array (22) comprises a plurality of capture elements (221) distributed along a rectangular array, and each capture element (221) corresponds to a local heat dissipation area on the chip (1).

5. The chip cooling system based on deformable phase change capsules according to claim 4 is characterized in that: The capture member (221) comprises a fixed end (222) and a movable end (223), wherein the fixed end (222) is embedded in the radiator substrate (21), and one end of the movable end (223) is suspended above the bottom wall of the coolant flow channel (211), and a groove (226) for accommodating the phase change capsule (5) is formed between the movable end (223) and the bottom wall of the coolant flow channel (211).

6. The chip cooling system based on deformable phase change capsules according to claim 5 is characterized in that: The movable end (223) comprises a U-shaped or door-shaped structure formed by two side rails (224) and a horizontal rail (225).

7. The chip cooling system based on deformable phase change capsules according to claim 6 is characterized in that: When the temperature of the capture member (221) is greater than the first threshold value, the capture member (221) is in an austenite state, and the distance between the horizontal bar (225) of the movable end (223) and the bottom wall of the coolant flow channel (211) is smaller than the diameter of the phase change capsule (5) in the solid spherical form, so that the phase change capsule (5) is constrained in the groove (226) by the side bar (224) and the horizontal bar (225), and the phase change capsule (5) can be squeezed out from the gap between the horizontal bar (225) and the bottom wall of the coolant flow channel (211) after absorbing heat, undergoing phase change and changing shape; When the temperature of the capture member (221) is lower than the second threshold value, the capture member (221) is in a martensite state, and the distance between the horizontal bar (225) of the movable end (223) and the bottom wall of the coolant flow channel (211) is greater than the diameter of the phase change capsule (5) in the solid spherical form, so that the phase change capsule (5) cannot be captured.

8. The chip cooling system based on deformable phase change capsules according to claim 1 is characterized in that: The phase change capsule (5) comprises a core and an outer shell, wherein the core is a paraffin-based phase change material, and the outer shell comprises a flexible inner layer and a wear-resistant outer layer.

9. A chip heat dissipation method based on deformable phase change capsules, characterized in that: Using the chip cooling system according to any one of claims 1 to 8, the chip cooling method comprises the following steps: Starting the liquid pump (4) to circulate the cooling liquid containing the phase change capsules (5) between the internal heat exchanger (2) and the external heat exchanger (3); When the temperature of a local area of ​​the chip (1) rises, causing the temperature of the capture element (221) in the corresponding area of ​​the built-in heat exchanger (2) to exceed the first threshold, the capture element (221) deforms and captures the phase change capsule (5) in the form of a solid sphere flowing through the area; When the temperature of a local area of ​​the chip (1) decreases, causing the temperature of the capture element (221) to be lower than the second threshold, the capture element (221) restores its shape and no longer captures the phase change capsule (5); The captured phase change capsule (5) absorbs heat and undergoes a phase change, and its shape changes and it detaches from the capturing member (221). The cooling liquid carrying the phase change capsule (5) after the phase change flows into the external heat exchanger (3). In the external heat exchanger (3), the phase change capsule (5) is cooled and restored to the solid spherical shape.

10. The chip heat dissipation method based on deformable phase change capsules according to claim 9, characterized in that: The phase change capsule (5) contacts the inner wall of the spiral channel (31) of the external heat exchanger (3) under the action of centrifugal force, and is driven by the micro-inclined fins (33) inside the spiral channel (31) to rotate in an undirected manner, while heat is dissipated through the coolant and the wall of the spiral channel (31) until the phase change capsule (5) returns to the solid spherical form.

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