A chip heat dissipation system and heat dissipation method based on deformation phase change capsules

Abstract

The present invention relates to the field of chip heat dissipation systems, and particularly to a chip heat dissipation system and a chip heat dissipation method based on deformation phase change capsules. The chip heat dissipation system includes a liquid pump, an internal heat exchanger, and an external heat exchanger. The coolant contains phase change capsules. 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 used to capture phase change capsules at the heat-generating part of the chip to enhance heat dissipation. The phase change capsules have an initial solid spherical form, and the phase change capsules rotate randomly in the spiral channel of the external heat exchanger and return to the initial form. The embodiments of the present invention use shape memory alloys to deform and capture phase change capsules, and at the same time use the deformation of the phase change capsules to break away from the capture, so that the phase change capsules can efficiently gather in the overheated area of the chip for fixed-point cooling, solving the low-efficiency problem of the traditional water cooling for the non-uniform overheated area with no differential cooling.

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 low efficiency 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:

[0006] 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;

[0007] The phase change capsules have an initial solid spherical form;

[0008] 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, and the capture member is made of a shape memory alloy material. 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;

[0009] The external heat exchanger includes a plurality of parallel spiral channels, and micro-inclined fins are formed inside the spiral channels for contacting the phase change capsules and forcing them to rotate and / or change their rotation directions to promote the cooling of the phase change capsules and their recovery to the solid spherical form.

[0010] Further, the cross-sectional shape of the spiral channel is rectangular, and an inlet pipe tangent to the spiral channel is connected to the inlet of the spiral channel.

[0011] Further, 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.

[0012] Further, 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.

[0013] Further, 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.

[0014] Further, it is characterized in that:

[0015] The movable end includes a U-shaped or gate-shaped structure formed by two side bars and a cross bar.

[0016] Further, it is characterized in that:

[0017] When the temperature of the capture member is greater than the first threshold, the capture member is in an 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 spherical 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;

[0018] When the temperature of the capture member is less than the second threshold, the capture member is in a 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 spherical form, so that the phase change capsule cannot be captured.

[0019] Further, 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.

[0020] 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:

[0021] Start the liquid pump to circulate the coolant containing the phase change capsule between the built-in heat exchanger and the external heat exchanger;

[0022] When the temperature of a local area of the chip rises, causing the temperature of the capture element in the corresponding area of the built-in heat exchanger to exceed the first threshold, the capture element deforms and captures the phase change capsule in the solid spherical form flowing therethrough;

[0023] When the temperature of the local area of the chip decreases, causing the temperature of the capture element to be lower than the second threshold, the capture element restores its shape and no longer captures the phase change capsule;

[0024] 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.

[0025] 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.

[0026] Compared with the prior art, this application has the following beneficial effects:

[0027] 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

[0028] 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.

[0029] Figure 1 is a system diagram of an embodiment of the present invention;

[0030] Figure 2 is a three-dimensional diagram of a heat sink substrate according to an embodiment of the present invention;

[0031] Figure 3 is a three-dimensional diagram of a capsule capture array according to an embodiment of the present invention;

[0032] Figure 4 A front view of a spiral channel according to an embodiment of the present invention;

[0033] Figure 5 The front view of the built-in heat exchanger according to an embodiment of the present invention;

[0034] Figure 6 is Figure 5 a sectional view taken along the A-A direction of

[0035] Figure 7 is Figure 5 a sectional view taken along the B-B direction of

[0036] Figure 8 The schematic diagram of the passing, capturing and disengaging process of the phase change capsule according to an embodiment of the present invention;

[0037] The reference numerals in the figure are respectively represented as follows:

[0038] 1 - chip; 2 - built-in heat exchanger; 21 - radiator 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 fin; 33 - micro inclined rib; 4 - liquid pump; 5 - phase change capsule. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0040] Two different regions of the same integrated circuit chip 1 may dissipate different thermal powers during operation, thereby causing local overheating. In this case, when the water cooling device can fully cool the hottest region of the chip 1, the cooling effect of the coldest region of the chip 1 exceeds the necessary degree, resulting in unnecessary power consumption of the pump for the circulating coolant in the device.

[0041] To solve this problem, the present 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 equilibrium in each region of the chip 1.

[0042] The core method adopted by the chip cooling system is: use a coolant containing phase change capsules 5 to liquid-cool the chip 1. The initial shape of the phase change capsules 5 is a solid sphere. A capsule catcher is set in the coolant flow channel 211 of the heat sink substrate 21 of the chip 1. The capsule catcher fixes the phase change capsules 5 in the overheating area of the chip 1, thereby achieving local enhanced cooling of the chip 1. After the phase change, the shape of the phase change capsules 5 changes, thereby breaking free from the constraints of the capsule catcher and returning to a solid sphere during the reflux process.

[0043] Specifically, refer to Figure 1 The chip cooling system includes: an internal 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 internal 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 a phase change heat absorption function and can be suspended in the coolant.

[0044] The built-in heat exchanger 2 includes a heat sink substrate 21 and a capsule capture array 22 .

[0045] refer to Figure 2 The 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 .

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Preferably, heat dissipation fins 32 are integrated on the outer wall of each spiral channel 31. The external heat exchanger 3 further includes a fan for guiding the outside air to convect with the outer wall of the spiral channel 31 and the heat dissipation fins 32. The heat dissipation fins 32 and the fan are not shown in the figure.

[0050] Preferably, deionized water is used as the coolant, and the liquid pump 4 is selected to be of a type that can stably transport the fluid containing the phase change capsules 5, such as a centrifugal pump with low shear force.

[0051] Preferably, referring to Figure 5 、 Figure 6 and Figure 7 , each capturing member 221 corresponds to a local heat dissipation area. The local heat dissipation area refers to the part on the contact portion between the chip 1 and the radiator substrate 21 that corresponds to the heat generation core inside the chip 1. These local heat dissipation areas usually follow a rectangular array distribution, so as to correspond to the layout of the heat generation cores inside the chip 1.

[0052] Preferably, referring to 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 in sequence along the flow direction of the coolant. The fixed end 222 is embedded in the radiator substrate 21 near the heat source of the chip 1 to ensure rapid thermal response. The movable end 223 is suspended above the radiator substrate 21 to perform the action of capturing the phase change capsules 5.

[0053] 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 form of a solid sphere. The surface of the cross bar 225 in contact with the phase change capsule 5 can be designed as an arc or an obtuse angle.

[0054] When the temperature of the capturing member 221 is greater than the first threshold, the capturing member 221 is in the austenite state, and 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 hits 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 to achieve reliable capture until the phase change capsule 5 undergoes a liquefaction phase change and then changes its own shape and is extruded from the gap between the top of the movable part and the bottom wall of the coolant flow channel 211.

[0055] When the temperature of the capturing member 221 is less than the second threshold, the capturing member 221 is in the martensite state, and 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 hits 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.

[0056] The core of the phase change capsule 5 uses RT65 paraffin-based phase change material (phase change temperature is 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 volume change during the phase change of the core. The outer layer is polyurea or modified melamine resin that is harder and more wear-resistant, 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.

[0057] The cooling method adopted by the chip heat dissipation system is as follows:

[0058] 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.

[0059] Overheat formation and capture of the phase change capsule 5: When the temperature of a certain area of the chip 1 rises, the temperature of the corresponding capture part 221 exceeds T1 (70°C) through substrate conduction. The capture part 221 deforms, capturing and fixing the solid phase change capsule 5 flowing through here on the bottom wall of the flow channel in the hot spot area.

[0060] 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, and the internal paraffin melts (about 65°C). The shape of the phase change capsule 5 changes, and it can be deformed and extruded from the gap between the capture part 221 and the bottom wall under the action of the coolant flow.

[0061] Overheat mitigation 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 drops. When the temperature is lower than T2 (60°C), the capture part 221 returns to its cold state shape and no longer captures the phase change capsule 5.

[0062] Regeneration and shape recovery of the phase change capsule 5: The coolant carrying the liquefied phase change capsule 5 enters the external heat exchanger 3. In the spiral channel 31, it is continuously stirred by the inclined microfins, and the liquefied phase change capsule 5 undergoes random and continuous tumbling and rotation. 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 cools evenly and re-solidifies, causing the phase change capsule 5 to return to a solid spherical shape. The phase change capsule 5 that has returned to a solid spherical shape leaves the external heat exchanger 3 with the coolant.

[0063] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the embodiments of the present invention.

Claims

1. A chip heat dissipation system based on deformed phase change capsules, characterized in that it includes a built-in heat exchanger (2) and an external heat exchanger (3) connected by a liquid pump (4), and the liquid pump (4) circulates a coolant containing phase change capsules (5) between the built-in heat exchanger (2) and the external heat exchanger (3); the phase change capsules (5) have an initial solid spherical form; the built-in heat exchanger (2) includes a radiator substrate (21) and a capsule capture array (22), the radiator substrate (21) fits the heat-generating surface of the chip (1), and a coolant flow channel (211) is formed inside it. The capsule capture array (22) is arranged on one side of the coolant flow channel (211) close to the heat-generating surface of the chip (1). The capsule capture array (22) includes at least one capture member (221), and the capture member (221) is made of a shape memory alloy material. The capture member (221) is configured to: when its temperature is greater than a first threshold, deform into a shape capable of capturing the phase change capsules (5) in the solid spherical form; when its temperature is less than a second threshold, deform into a shape that cannot capture the phase change capsules (5) in the solid spherical form; the external heat exchanger (3) includes a plurality of parallel spiral channels (31), and micro-inclined fins (33) for contacting the phase change capsules (5) and forcing them to rotate and / or change their rotation direction are formed inside the spiral channels (31) to promote the cooling of the phase change capsules (5) and their recovery to the solid spherical form.

2. The chip heat dissipation system based on deformed phase change capsules according to claim 1, characterized in that the cross-sectional shape of the spiral channel (31) is rectangular, and an inflow pipe tangent to the spiral channel (31) is connected to the inlet of the spiral channel (31).

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

4. The chip heat dissipation system based on the deformation phase change capsule according to claim 2, characterized in that The capsule capture array (22) includes a plurality of the capture members (221) distributed in a rectangular array, and each capture member (221) corresponds to a local heat dissipation area on the chip (1).

5. The chip heat dissipation system based on the deformation phase change capsule according to claim 4, characterized in that, The capture member (221) includes a fixed end (222) and a movable end (223), the fixed end (222) is embedded in the radiator substrate (21), 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 capsules (5) is formed between the movable end (223) and the bottom wall of the coolant flow channel (211).

6. The chip heat dissipation system based on deformed phase change capsules according to claim 5, characterized in that: the movable end (223) includes a U-shaped or door-shaped structure formed by two side bars (224) and a cross bar (225).

7. The chip heat dissipation system based on deformed phase change capsules according to claim 6, 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 heat dissipation system based on the deformation phase change capsule according to claim 1, 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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