Diamond-copper composite micro-channel cooling packaging structure

Abstract

The application relates to the technical field of semiconductor packaging cooling, and particularly discloses a diamond-copper composite micro-flow channel cooling packaging structure, which comprises a packaging shell and a diamond-copper heat conduction plate which is floatingly connected to the bottom of the packaging shell through an elastic sealing ring; a plurality of heat exchange columns are integrally formed on the upper surface of the heat conduction plate, each heat exchange column is inserted into a receiving counterbore of the packaging shell to form a micro-flow channel annular gap; a piezoelectric vibration plate is integrated in the packaging shell and is used for separating a medium cavity into a storage cavity and a jet flow cavity; the jet flow cavity is communicated with a flexible connecting pipe section which is suspended above the heat exchange columns; the surface of the heat exchange column is provided with a spiral fin, the opening of the receiving counterbore is provided with a horn-shaped flow guide piece, and the bottom surface of the heat conduction plate is provided with C-shaped groove flow guide fins which are arranged in a staggered mode; the application realizes low-thermal-resistance, high-flux and high-reliability direct contact type active heat dissipation for high-power-density devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor packaging cooling, in particular to a diamond-copper composite micro-channel cooling packaging structure. BACKGROUND

[0002] With the rapid development of the third generation semiconductor technology (such as SiC, GaN), power devices such as insulated gate bipolar transistors (IGBT), high-power lasers and high-performance processors are evolving towards miniaturization, integration and extremely high power density, which leads to an exponential increase in heat flux density when the device is working, and some core areas even exceed 1000W / cm². In the field of electronic packaging, effective thermal management is the key to ensuring the long-term reliable operation of the device. Under normal circumstances, the packaging structure of such high-power devices needs to quickly and low-thermal-resistance conduct the generated heat to the external cooling medium, so the packaging shell and the internal heat dissipation structure not only play the role of mechanical support and environmental protection, but also are the core path of heat removal, and the heat dissipation efficiency directly determines the performance upper limit and service life of the device.

[0003] In order to cope with the above-mentioned extremely high heat flux density cooling challenge, the existing mainstream technical solution usually adopts copper or aluminum alloy as the heat-conducting substrate, and mainly exchanges heat through micro-channel liquid cooling technology, which is mainly manifested in the following specific technical forms: parallel micro-channels are processed inside the substrate, or nozzle arrays are used to vertically jet impact cooling on the planar area at the bottom of the substrate. In addition, in the system integration architecture, the existing technology usually adopts a separate packaging design in order to balance insulation and versatility, that is, a separate liquid cooling module is attached to the packaging bottom surface of the heat-generating component through a heat-conducting interface material (TIM) to realize heat transfer and dissipation.

[0004] However, it still has certain limitations in actual application: first, the existing jet impact technology mainly acts on the flat two-dimensional surface, and the effective heat exchange area is limited; and after jet impact on the plane, the waste heat fluid will flow laterally along the wall, seriously interfering with the fresh jet of the adjacent nozzle, resulting in a decrease in the overall heat exchange uniformity of the array, which is difficult to meet the uniform temperature requirement under extreme working conditions; secondly, the separate packaging introduces high contact thermal resistance, and the traditional architecture excessively relies on the TIM layer connector to connect the device and the heat sink. Since the thermal conductivity of the TIM is much lower than that of the metal matrix, the contact thermal resistance introduced by this multi-layer medium structure often accounts for a large proportion of the total thermal resistance, which becomes a structural shortcoming that restricts the overall heat dissipation performance of the system.

[0005] Therefore, it is urgent to propose a diamond-copper composite micro-channel cooling packaging structure. SUMMARY

[0006] The main purpose of the present application is to provide a diamond-copper composite micro-channel cooling packaging structure, aiming to at least solve the technical problems of low heat exchange efficiency caused by horizontal flow interference and limited heat exchange area of planar impact cooling structure in the prior art, and excessive contact thermal resistance caused by relying on the layer of thermal interface material of the traditional separate packaging structure.

[0007] To achieve the above-mentioned purpose, the present application provides a diamond-copper composite micro-channel cooling packaging structure, which comprises a packaging shell, a containing cavity is formed in the packaging shell, a heat conduction plate is arranged in the middle of the inside of the containing cavity, the heat conduction plate is used to divide the containing cavity into an upper device cavity and a lower cooling chamber along the height direction, a heat-generating component is installed in the upper device cavity, one side surface of the heat conduction plate facing the upper device cavity is a heat-conducting bearing surface for bearing the heat-generating component, and the other side surface of the heat conduction plate is provided with a plurality of heat exchange columns arranged in an array downward.

[0008] A medium cooling component is embedded in the lower cooling chamber, a medium flow gap is formed between the upper part of the medium cooling component and the bottom of the heat conduction plate, and the upper surface of the medium cooling component is provided with a plurality of containing counterbores corresponding to the heat exchange columns, the heat exchange columns are inserted into the containing counterbores and form annular gaps with the containing counterbores, and a medium jet pipe is installed at the center of the hole bottom of the containing counterbores, the medium jet pipe is used to spray cooling medium to the bottom end of the heat exchange column.

[0009] In some optional embodiments, a medium cavity is formed in the inside of the medium cooling component, the inside of the medium cavity is filled with cooling medium and is divided into a jet cavity located at the upper part and a storage cavity located at the lower part by a piezoelectric vibration plate, the jet cavity is communicated with the medium jet pipe, a one-way through hole is arranged on the piezoelectric vibration plate and points from the storage cavity to the jet cavity, the piezoelectric vibration plate pumps the cooling medium in the storage cavity to the jet cavity through the one-way through hole by high-frequency vibration, and forces the cooling medium in the jet cavity to be sprayed out of the medium jet pipe.

[0010] Further, the height of the jet cavity is 1 / 5 to 1 / 3 of the height of the storage cavity.

[0011] In some optional embodiments, the medium jet pipe comprises a flexible connecting pipe section and a jet spout located at the top end of the flexible connecting pipe section, the bottom end of the flexible connecting pipe section is fixedly connected to the center of the hole bottom of the containing counterbores and extends into the jet cavity, and the flexible connecting pipe section is configured to elastically deform and swing when the cooling medium is sprayed out of the jet spout, so as to drive the jet spout to dynamically spray the heat exchange column.

[0012] Further, the heat conduction plate is made of diamond-copper composite material, and the heat exchange column is integrally formed with the heat conduction plate.

[0013] In some alternative embodiments, the outer circumferential surface of the heat exchange column is provided with helical ribs extending along the axial direction, and the helical ribs are located in the annular gap.

[0014] In some alternative embodiments, a flow guide is further arranged at the upper opening of each accommodating hole, and the flow guide is a trumpet-shaped elastic metal thin-walled tube, the bottom end of which is fixedly connected to the inner wall of the hole opening of the accommodating hole, the top end of the elastic metal thin-walled tube extends into the medium flooding gap and is outwardly folded to form a flow guide curved surface with a circular arc cross section, and the end edge of the flow guide curved surface extends upward to the bottom surface of the heat conduction plate.

[0015] Further, a medium outflow pipe is further arranged at the position corresponding to the medium flooding gap on one side of the packaging shell.

[0016] In some alternative embodiments, a plurality of flow guide ribs are arranged at the upper part of the medium flooding gap and on the bottom surface of the heat conduction plate, the plurality of flow guide ribs are staggered and arranged between the heat exchange columns, and the side surface of the flow guide rib towards the flow guide is recessed to form a C-shaped flow collecting groove.

[0017] In some alternative embodiments, the inner wall of the packaging shell is provided with an annular support step for supporting the edge of the heat conduction plate, the edge of the heat conduction plate is overlapped on the annular support step, and a high-temperature-resistant elastic sealing ring is arranged between the edge of the heat conduction plate and the annular support step.

[0018] Compared with the prior art, the present application can achieve at least the following beneficial effects:

[0019] 1. The present application uses the heat exchange column inserted into the accommodating hole to construct an independent three-dimensional heat exchange unit, converts the traditional planar jet into a three-dimensional cylindrical cladding heat exchange, significantly increases the heat exchange area, and avoids the lateral interference between adjacent jet units through physical isolation, effectively solving the heat dissipation bottleneck under high heat flux density.

[0020] 2. The present application uses a diamond-copper composite heat conduction plate as a packaging base to cancel the traditional thermal interface material layer to construct a direct heat path from the chip to the cooling liquid, thereby greatly reducing the system contact thermal resistance and meeting the heat dissipation demand of high-power-density devices.

[0021] 3. The present application uses a piezoelectric vibration plate to cooperate with a flexible connection pipe section to generate a pulsating oscillating jet, which not only destroys the thermal boundary layer on the surface of the column through pulsating impact, but also expands the cooling coverage by means of the oscillating scanning of the pipe section, thereby effectively eliminating local high-temperature hot spots.

[0022] 4、The heat exchange column surface of the application is provided with spiral fins to increase the heat exchange area and straighten the flow field, the spiral centrifugal motion strengthens the scouring force of the fluid on the wall surface, and effectively prolongs the heat exchange path of the cooling medium in the gap.

[0023] 5、The application uses the horn-shaped flow guide of the orifice to guide the jet flow to flow flat on the bottom surface of the heat conduction plate to eliminate the blind area of heat dissipation, and uses the convex structure to block the fluid interference at the outlet of the adjacent unit, ensuring the independence of heat dissipation of each unit.

[0024] 6、The application uses the C-shaped groove flow guide fin staggered arranged at the bottom of the heat conduction plate to force the fluid to separate from the wall surface and produce longitudinal rolling, thereby promoting the full mixing of deep cold and hot fluids, and effectively avoiding the problem of thermal short circuit caused by direct discharge of the medium. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0026] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the application;

[0027] Figure 2 It is a schematic diagram of the internal structure of the application;

[0028] Figure 3 It is a schematic diagram of the containing counterbore in the application Figure 2

[0029] Figure 4 It is a schematic diagram of the bottom structure of the heat conduction plate of the application.

[0030] In the above drawings, the reference numerals are: 1, package shell; 11, upper device cavity; 12, lower cooling chamber; 2, heat conduction plate; 21, heat exchange column; 211, spiral fin; 3, medium cooling piece; 31, medium turbulent flow gap; 311, flow guide fin; 32, containing counterbore; 33, medium jet pipe; 341, jet cavity; 342, storage cavity; 35, flow guide; 36, piezoelectric vibration plate; 361, one-way through hole; 4, medium outflow pipe; 5, heat generating component.

[0031] The implementation of the purpose of the application, functional characteristics and advantages will be further described below with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0032] ​The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0033] It should be noted that all directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directionality indications also change accordingly.

[0034] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "connection" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In addition, if the present application has descriptions involving "first", "second" and the like, the "first", "second" and the like are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes A solution, or B solution, or A and B solutions. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0036] Embodiment:

[0037] The embodiment provides a diamond-copper composite micro-channel cooling packaging structure. Obviously, the structure is applied to a power semiconductor device thermal management system with extremely high heat flux density characteristics. Specifically, it is located between a heat-generating electronic component (such as an IGBT chip, a radio frequency power amplifier or a high-power laser) and an external cooling circulation loop, and is used for mechanically supporting and protecting the heat-generating electronic component and quickly and low-thermal-resistance conducting core heat generated by the heat-generating electronic component to the internally flowing cooling medium to realize high-efficiency heat dissipation.

[0038] For example, refer to Figures 1 to 3 The specific structure comprises a packaging shell 1, and a containing cavity is formed in the packaging shell 1. The packaging shell is characterized in that a heat conduction plate 2 is arranged in the middle of the inside of the containing cavity, the heat conduction plate 2 is used for dividing the containing cavity into an upper device cavity 11 and a lower cooling chamber 12 along the height direction, a heat-generating component 5 is arranged in the upper device cavity 11, one side surface of the heat conduction plate 2 towards the upper device cavity 11 is a heat-conducting bearing surface for bearing the heat-generating component 5, and a plurality of heat exchange columns 21 arranged in an array are protruded downwards from the other side surface of the heat conduction plate 2.

[0039] A medium cooling component 3 is arranged in the lower cooling chamber 12. A medium flow gap 31 is formed between the upper part of the medium cooling component 3 and the bottom of the heat conduction plate 2. An upper surface of the medium cooling component 3 is provided with a plurality of containing counterbores 32 corresponding to the heat exchange columns 21. The heat exchange columns 21 are inserted into the containing counterbores 32 and form annular gaps with the containing counterbores 32. A medium jet pipe 33 is arranged at the center of the bottom of the containing counterbores 32. The medium jet pipe 33 is used for spraying cooling medium to the bottom end of the heat exchange columns 21.

[0040] It can be understood that in the existing high-power-density packaging technology, the traditional liquid cooling scheme mostly adopts a planar jet impact or a separated cooling plate bonding structure. In the analysis of the prior art, the technical personnel found that there are mainly two core defects, one is the horizontal flow interference and limited heat exchange surface in the fluid dynamics, that is, the waste heat fluid generated after the jet impact plane will flow disorderly along the wall surface, which seriously interferes with the fresh jet of the adjacent nozzle, and the two-dimensional plane heat exchange area has been difficult to meet the heat dissipation demand of kilowatt-level heat flux density; the other is the interface thermal resistance bottleneck in the packaging architecture, that is, the traditional separated structure depends on the connection of the thermal interface material (TIM) layer, and the high contact thermal resistance brought by the TIM layer limits the release of the device performance.

[0041] Therefore, the scheme as described in the above embodiment is proposed, which solves the technical problems of serious horizontal flow interference, insufficient effective heat exchange area and excessive interface contact thermal resistance in the existing traditional cooling packaging structure by arranging the heat exchange columns 21 and the containing counterbores 32 in the form of insertion and cooperation and the annular gap flow guide structure.

[0042] In the face of high heat flux conditions, the embodiment realizes efficient refrigeration of the packaging structure through the following mechanism: after the cooling medium is accelerated and sprayed out through the medium jet pipe 33, it vertically impacts the bottom end surface of the heat exchange column 21, and uses the high heat exchange coefficient of the impact stagnation point to take away most of the heat transferred by the heat conduction plate 2. Subsequently, due to the constraint of the side wall of the accommodating counterbore 32, the fluid cannot spread laterally as in the traditional plane, but is forced to enter the narrow annular gap, and is converted into a wall jet flowing vertically upward along the side wall surface of the heat exchange column 21, and finally enters the medium turbulent flow gap 31; this process first relies on the independent physical isolation mechanism formed by the heat exchange column 21 inserted into the accommodating counterbore 32 to forcibly constrain the backflow path of the fluid after impact, completely blocking the lateral flow interference between adjacent accommodating counterbores 32, ensuring the independence and uniformity of the jet impact process for each heat exchange column 21; secondly, using the outer peripheral side wall of the heat exchange column 21, the heat exchange interface is expanded from a single bottom surface to a three-dimensional contact form of "bottom surface + side cylindrical surface", greatly increasing the effective heat dissipation area of solid-liquid contact; finally, based on the direct integration of the heat conduction plate 2 as the base of the packaging shell 1, the thermal interface material (TIM) layer in the traditional multilayer structure is eliminated, and a low-thermal-resistance integrated heat conduction path is constructed, thereby significantly improving the overall heat dissipation performance.

[0043] Based on the above embodiment, the structure of the medium cooling element 3 is further described as follows: Figure 2 As shown in the figure, a medium cavity is formed in the inside of the medium cooling element 3, the inside of the medium cavity is filled with cooling medium and is divided into a jet cavity 341 located at the upper part and a storage cavity 342 located at the lower part by a piezoelectric vibration plate 36, the jet cavity 341 is in communication with the medium jet pipe 33, a one-way through hole 361 is provided on the piezoelectric vibration plate 36 and points from the storage cavity 342 to the jet cavity 341, the piezoelectric vibration plate 36 pumps the cooling medium in the storage cavity 342 to the jet cavity 341 through the one-way through hole 361 by high-frequency vibration, and forces the cooling medium in the jet cavity 341 to be sprayed out from the medium jet pipe 33.

[0044] Specifically, the piezoelectric diaphragm 36 is configured to generate high-frequency mechanical vibration under the action of an external driving voltage, thereby forming a micro-pumping effect, that is, when the piezoelectric diaphragm 36 is bent and deformed downward, the storage cavity 342 below the piezoelectric diaphragm 36 is pressed, forcing the internal cooling medium to overcome the positive flow resistance and be pumped into the upper jet flow cavity 341 (suction stroke) through the one-way through hole 361; and when the piezoelectric diaphragm 36 is reset upward or vibrates reversely, the internal volume of the jet flow cavity 341 shrinks, causing the internal pressure to rise sharply, at which time the one-way through hole 361 is in a fluid cutoff state (that is, the fluid is effectively prevented from flowing back to the storage cavity 342 by using a great reverse flow resistance), thereby forcing the cooling medium in the jet flow cavity 341 to be ejected at a high speed in the form of a high-frequency pulse from the medium jet flow pipe 33 to the bottom end of the heat exchange column 21 (discharge stroke).

[0045] It can be understood that, by the high-frequency pumping action of the piezoelectric diaphragm 36, the fluid motion mode in the medium jet flow pipe 33 is converted into a high-frequency pulsating jet flow, so that the pulsating flow field has periodic speed fluctuation characteristics and stronger shear stress, which can continuously actively flush and disturb the fluid thermal boundary layer wrapped around the heat exchange column 21, thereby effectively inhibiting the thickening of the thermal boundary layer and significantly strengthening the turbulence of the fluid at the micro solid-liquid contact surface. In this way, on the basis of ensuring compactness, the convective heat transfer coefficient and the limit heat dissipation capacity of the structure are further improved.

[0046] Obviously, for the piezoelectric diaphragm 36, it needs to be supplemented that the piezoelectric diaphragm 36 works based on the inverse piezoelectric effect, which can be electrically connected to an external high-frequency driving circuit through a flexible circuit (FPC) or a wire, and a technician can adjust the frequency and amplitude of the driving voltage according to the heat dissipation requirement; on the other hand, the piezoelectric diaphragm 36 (and the corresponding piezoelectric ceramic element) belongs to a general standard device that is mature in the existing electronic industry and can be directly purchased through commercial channels. The technician in the field can directly select and use according to the actual requirement without additional improvement on the manufacturing process of the device itself, so it is not within the protection scope of the present application.

[0047] Further, based on the above embodiment, the height of the jet flow cavity 341 is 1 / 5 to 1 / 3 of the height of the storage cavity 342.

[0048] It can be understood that the size ratio is a preferred engineering parameter interval obtained by the technical personnel based on the comprehensive analysis of the kinetic response characteristics of the cooling medium and the continuity requirements of the supply. By controlling the relatively small height (1 / 5 to 1 / 3) of the jet chamber 341, the compression dead volume of the jet chamber 341 can be significantly reduced, so that when the piezoelectric vibration plate 36 produces a small deformation, a high-amplitude transient pressure can be quickly established in the chamber, and the initial speed of the cooling medium ejected from the medium jet pipe 33 is improved. At the same time, the relatively large height of the storage chamber 342 matched with it can act as a buffer pool to ensure sufficient and stable cooling medium supply for the jet chamber 341, and prevent the phenomenon of air suction or cavitation due to supply lag during high-frequency pumping.

[0049] It should be noted that the above ratio range is not an absolute limit, but a best efficiency balance point for typical cooling media such as electronic fluorinated liquid and deionized water under conventional piezoelectric driving frequency. If the height of the jet chamber 341 accounts for less than 1 / 5, the along-the-way resistance of the cooling medium flowing through the channel will increase significantly, which is easy to cause pumping delay; if the ratio is higher than 1 / 3, it is difficult to form an impact momentum sufficient to break the thermal boundary layer under the limited piezoelectric amplitude. Therefore, limiting the numerical range helps to achieve the best balance between high-frequency response and stable flow, thereby ensuring the overall heat dissipation performance of the package structure.

[0050] Further, based on the above embodiment, here a more preferred implementation is proposed for the medium jet pipe 33, as shown in Figure 3 The medium jet pipe 33 includes a flexible connection pipe segment and a jet nozzle at the top end thereof, the bottom end of the flexible connection pipe segment is fixedly connected to the center of the hole bottom of the accommodating counterbore 32 and extends into the jet chamber 341, and the flexible connection pipe segment is configured to elastically deform and swing when the cooling medium is ejected from the jet nozzle, so as to drive the jet nozzle to dynamically spray the heat exchange column 21.

[0051] It can be understood that in the structure of using a rigid pipe for jet impact, there is still a certain heat dissipation limitation. That is, if the medium jet pipe 33 is completely rigid, the fluid ejected therefrom can only aim at the same center point at the bottom end of the heat exchange column 21 all the time, and such single-position fixed-point impact will cause the heat exchange column 21 to form a radial thermal gradient with low center temperature and high edge temperature on the bottom surface, resulting in uneven local heat exchange and difficulty in fully utilizing the entire area of the bottom end of the heat exchange column 21 for efficient heat dissipation.

[0052] Accordingly, in the embodiment, the traditional overall rigid pipe design is abandoned, and an improved design of flexible connecting pipe segment + jet nozzle is adopted. In actual working process, when the pressurized electrically driven cooling medium flows through the flexible connecting pipe segment in a pulsating form, the periodic pressure fluctuation and impact force inside the cooling medium will force the flexible connecting pipe segment with elasticity to continuously deform and sway, thereby driving the jet nozzle at the top end of the flexible connecting pipe segment to swing around the axis of the accommodating counterbore 32 with a small amplitude.

[0053] Therefore, through the above structure, the self-excited swing of the medium jet pipe 33 without external mechanical driving components is realized, and the jet nozzle is driven to implement dynamic scanning injection at the bottom end of the heat exchange column 21, so that the sprayed cooling medium is no longer limited to impacting a single point, but can cover a wider area at the bottom end of the heat exchange column 21, thereby effectively avoiding local heat accumulation and radial temperature difference caused by fixed single-point injection, significantly improving the temperature uniformity of the bottom surface of the heat exchange column 21, and further promoting the dynamic heat exchange between the cooling medium and the surface of the heat exchange column 21 by the physical swing of the pipe body, thereby significantly improving the overall heat dissipation efficiency of the packaging structure.

[0054] As a further embodiment of the present application, the heat conduction plate 2 is made of diamond-copper composite material, and the heat exchange column 21 is integrally formed with the heat conduction plate 2.

[0055] It should be noted that the diamond-copper composite material is selected in the present application, which aims to utilize its extremely high thermal conductivity (usually up to 600 W / m·K or more) and thermal expansion coefficient matching the semiconductor chip, thereby ensuring rapid heat conduction while reducing packaging thermal stress.

[0056] More importantly, through the structure design of integral molding (such as integral molding by mold infiltration process), the heat exchange column 21 directly extends from the body of the heat conduction plate 2, and there is no physical interface or connecting solder between the two, so as to completely eliminate the interface contact thermal resistance between the substrate and the heat dissipation structure through the continuity of the structure, ensuring that the heat absorbed by the heat conduction plate 2 can be conducted to the heat exchange column 21 without loss with minimum heat transfer resistance, and taken away by the cooling medium.

[0057] Further, as a further preferred embodiment, in Figure 2 and Figure 4 It has been shown that the outer peripheral surface of the heat exchange column 21 is convexly provided with a spiral rib 211 extending in the axial direction, and the spiral rib 211 is located in the annular gap.

[0058] It can be understood that the present scheme significantly increases the effective solid-liquid contact area of the outer peripheral side wall of the heat exchange column 21 by setting the above-mentioned spiral rib 211, thereby reducing the surface thermal resistance without changing the packaging volume; at the same time, the spiral rib 211 cooperates with the inner wall surface of the accommodating counterbore 32 to construct a spiral flow channel that spirally rises along the axial direction from the originally flat annular gap, thereby realizing forced flow guiding and path lengthening of the cooling medium, so that the cooling medium can have more time and path for sufficient heat exchange in the annular gap.

[0059] Further, the spiral flow channel structure constructed by the spiral rib 211 and the annular gap can also effectively improve the flow field pattern under the swing injection of the flexible pipe. Specifically, for the disordered turbulent flow generated by the dynamic swing scanning of the flexible connecting pipe section, the spiral rib 211 can also play a role of "flow field regularization": that is, by using the physical boundary of the spiral channel, the disordered cooling medium generated by the swing impact at the bottom is constrained and guided to form a spiral flow with centrifugal characteristics along the surface of the column; this flow state helps to induce the generation of secondary flow, thereby strengthening the continuous flushing and disturbance of the cooling medium to the thermal boundary layer on the surface of the spiral rib 211, thereby realizing the synergistic improvement of the convective heat transfer efficiency.

[0060] Further, based on the above-mentioned embodiment, in order to optimize the flow field connection and diffusion pattern of the cooling medium after flowing out of the accommodating counterbore 32, the present scheme is further provided with a flow guiding piece 35 at the upper opening of each of the accommodating counterbores 32. Specifically, please refer to Figure 3 , the flow guiding piece 35 is a horn-shaped elastic metal thin-walled pipe, the bottom end of which is fixedly connected to the inner wall of the opening of the accommodating counterbore 32, thereby forming a continuous flow channel extension with the hole wall; the top end of the elastic metal thin-walled pipe extends into the medium flooding gap 31 and is folded outward, forming a flow guiding curved surface with a circular arc cross section, and the end edge of the flow guiding curved surface extends upward to near the bottom surface of the heat conduction plate 2, thereby forming a tapered radial injection channel between the flow guiding curved surface and the bottom surface of the heat conduction plate 2.

[0061] It can be understood that the introduction of this structure mainly solves the problems of sudden expansion flow resistance and heat exchange blind area of the cooling medium when it rushes out of the accommodating counterbore 32 into the wide gap.

[0062] Firstly, based on the setting of the circular arc flow guiding curved surface, it changes the flow field sudden change of the traditional right-angle outlet, that is, when the cooling medium climbs up to the opening at a high speed along the spiral rib 211, the flow guiding curved surface uses the wall attachment effect to guide the cooling medium to smoothly change from axial vertical flow to radial horizontal flow when flowing out of the accommodating counterbore 32 along the circular arc tangent direction, thereby to a certain extent, inhibiting the separation vortex generated at the edge of the opening, and significantly reducing the local pressure loss of the cooling medium when entering the flooding gap;

[0063] Secondly, the flow guide 35 substantially extends the cooling range of the heat exchange column 21 in the radial direction, that is, by extending the end of the flow guide surface to the vicinity of the bottom surface of the heat conduction plate 2, the discharged cooling medium forms a wall-adhering radial jet, directly flushing the bottom surface of the heat conduction plate 2 around the heat exchange column 21, which makes the inter-columnar area, which is prone to heat accumulation, also directly cooled by high-speed fluid, thereby further improving the overall uniformity of the heat conduction plate 2.

[0064] In addition, based on the structure layout of the flow guide 35 protruding into the receiving recess 32, it spatially constructs an independent liquid discharge flow guide barrier. Specifically, among the arrayed multiple heat dissipation units, the protruding flow guide 35 can effectively block the disordered transverse flow of the waste heat medium flowing out of a single receiving recess 32 in the flow gap, so as to avoid the high-flow-rate waste heat medium directly transversely flushing or covering the outlet area of the adjacent receiving recess 32 and flowing into it again, thereby preventing fluid dynamic interference or thermal cross-talk between adjacent heat dissipation units, and ensuring that the cooling medium in each receiving recess 32 can be independently and smoothly discharged into the medium flow gap 31.

[0065] Based on the above embodiments, it is further pointed out here that, as shown in Figure 1 and Figure 2 , a medium outflow pipe 4 is further provided at the position corresponding to the medium flow gap 31 on one side of the packaging shell 1.

[0066] It can be understood that the medium outflow pipe 4 is used to guide the cooling medium after heat exchange in the medium flow gap 31 to the outside of the packaging shell 1, so as to prevent the accumulation or backflow of hot fluid in the cavity.

[0067] And as a further preferred, the cooling medium discharged through the medium outflow pipe 4 can be transported to an external heat exchange unit (such as an air-cooled radiator or a condenser) for cooling treatment, and after filtration and degassing operation, it is stored in an external medium storage tank, and finally reenters the medium cavity of the medium cooling member 3 through a circulating pipeline, so as to realize the closed-loop circulation use of the cooling medium; and the storage cavity 342 in the medium cavity can be connected to the external medium storage tank through a medium inflow pipe, so as to provide continuous and stable medium supply to the storage cavity 342.

[0068] It should be noted that based on the above structure, the storage cavity 342 can utilize the flow resistance difference characteristics to achieve passive control of the fluid direction. Specifically, since the external medium inflow pipe usually has a long pipe length or a small pipe diameter, the flow resistance along the pipe for instantaneous high-frequency flow is much larger than that of the upper jet flow path. Therefore, when the piezoelectric vibration plate 36 vibrates at a high frequency, it is difficult for the large volume of fluid in the storage cavity 342 to overcome the high flow resistance of the inflow pipe and cause instantaneous reverse backflow. On the contrary, the pressure wave generated by the piezoelectric vibration is forced to be constrained and converted into kinetic energy for driving the medium in the jet flow cavity 341 to be ejected upward, thereby ensuring that the cooling medium can be effectively ejected from the medium jet pipe 33.

[0069] Obviously, the cooling medium in the present scheme preferably uses electronic fluorinated liquid or low-viscosity insulating oil. Such medium has extremely low kinematic viscosity and good fluidity, which can ensure that a high flow rate of jet flow can be formed under the driving of a small piezoelectric amplitude, and its excellent insulation performance guarantees the electrical safety of direct contact cooling.

[0070] Based on the above embodiment, it is further preferred to implement the following manner: Figure 4 As shown in the above embodiment, a plurality of flow guide ribs 311 are arranged on the upper part of the medium turbulent flow gap 31 and on the bottom surface of the heat conduction plate 2, the plurality of flow guide ribs 311 are arranged in a staggered manner between the heat exchange columns, and the side surface of the flow guide ribs 311 facing the flow guide member 35 is recessed to form a C-shaped flow collecting groove.

[0071] As can be understood, the C-shaped flow collecting groove is used to receive the wall-adhering horizontal jet flow guided by the flow guide member 35, and force the wall-adhering horizontal jet flow to roll over the bottom surface of the heat conduction plate 2 and downward, thereby forming a longitudinal mixing vortex that rolls the near-wall hot fluid into the deep part of the turbulent flow gap.

[0072] In this way, the present scheme effectively solves the problem that the cooling medium is easy to form a laminar boundary layer at the top of the turbulent flow gap. With the interception of the flow guide ribs 311 and the rolling effect of the C-shaped groove, the fluid originally flowing close to the high-temperature wall is forced to be stripped and pushed to the deep part of the gap, and intense mixing occurs with the low-temperature fluid below. At the same time, the staggered arrangement of the ribs further breaks the straight flow path of the cooling medium, ensuring that the cooling medium can fully traverse the entire heat exchange area in a circuitous flow form in the medium turbulent flow gap 31, thereby effectively avoiding the "thermal short circuit" phenomenon caused by straight flow of fluid, and significantly prolonging the effective residence time of the cooling medium in the high-temperature area, and achieving uniform extraction of heat from the bottom surface of the heat conduction plate 2.

[0073] Based on the above embodiment, it is further necessary to note that the inner wall of the packaging shell 1 is provided with an annular support step for supporting the edge of the heat conduction plate 2, the edge of the heat conduction plate 2 is lapped on the annular support step, and a high-temperature-resistant elastic sealing ring is clamped therebetween.

[0074] It can be understood that, based on the above matching structure, when the heat conduction plate 2 is pressed on the annular support step, the high-temperature-resistant elastic sealing ring plays a key sealing and buffering role between the two. On the one hand, the high-temperature-resistant elastic sealing ring fills the micro assembly gap between the heat conduction plate 2 and the metal shell by using its own compression elasticity, and ensures the liquid tightness of the packaging cavity when it is subjected to internal medium pressure impact.

[0075] On the other hand, it acts as a flexible damping medium, which can effectively absorb the micro displacement generated by piezoelectric high-frequency vibration, avoid the hard collision between the fragile heat conduction plate 2 (such as diamond composite material) and the rigid metal step, and cause damage, and can release the transverse thermal stress generated by the heat conduction plate 2 and the packaging shell 1 due to the difference in coefficient of thermal expansion (CTE) through its elastic deformation, thereby physically ensuring the long-term operation stability of the packaging structure.

[0076] Finally, it should be noted that in this paper, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or system. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of another identical element in the process, method, article or system including the element.

[0077] In addition, it should be noted that the structure, proportion, size, etc. shown in the drawings attached to the present specification are schematic drawings, which are only used to cooperate with the disclosed content for understanding and reading by those skilled in the art, and are not used to define the limiting conditions for the implementation of the present application, so they do not have technical substantive significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the disclosed technical content.

Claims

1. A diamond-copper composite microfluidic cooling encapsulation structure, comprising an encapsulation shell (1), wherein an accommodating cavity is formed inside the encapsulation shell (1), characterized in that, A heat conduction plate (2) is provided in the middle of the cavity. The heat conduction plate (2) is used to divide the cavity into an upper device cavity (11) and a lower cooling chamber (12) along the height direction. A heating element (5) is installed in the upper device cavity (11). The surface of the heat conduction plate (2) facing the upper device cavity (11) is a heat-conducting bearing surface for supporting the heating element (5). The other surface of the heat conduction plate (2) is provided with a plurality of heat exchange columns (21) arranged in an array. A medium cooling component (3) is embedded in the lower cooling chamber (12). A medium flow gap (31) is formed between the upper part of the medium cooling component (3) and the bottom of the heat conduction plate (2). The upper surface of the medium cooling component (3) is provided with a plurality of receiving countersunk holes (32) corresponding one-to-one with the heat exchange column (21). The heat exchange column (21) is inserted into the receiving countersunk hole (32) and forms an annular gap with it. A medium jet pipe (33) is installed at the center of the bottom of the receiving countersunk hole (32). The medium jet pipe (33) is used to spray cooling medium to the bottom end of the heat exchange column (21).

2. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, A medium cavity is formed inside the medium cooling component (3). The medium cavity stores cooling medium and is divided into an upper jet cavity (341) and a lower storage cavity (342) by a piezoelectric vibrating plate (36). The jet cavity (341) is connected to the medium jet pipe (33). A one-way through hole (361) is provided on the piezoelectric vibrating plate (36) pointing from the storage cavity (342) to the jet cavity (341). The piezoelectric vibrating plate (36) pumps the cooling medium in the storage cavity (342) to the jet cavity (341) through the one-way through hole (361) by high-frequency vibration, and forces the cooling medium in the jet cavity (341) to be ejected from the medium jet pipe (33).

3. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 2, characterized in that, The height of the jet cavity (341) is 1 / 5 to 1 / 3 of the height of the storage cavity (342).

4. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 2, characterized in that, The medium jet pipe (33) includes a flexible connecting pipe section and a jet nozzle at its top. The bottom end of the flexible connecting pipe section is fixedly connected to the center of the bottom of the receiving hole (32) and extends into the jet cavity (341). The flexible connecting pipe section is configured to undergo elastic deformation and swing when the jet nozzle sprays out the cooling medium, so as to drive the jet nozzle to dynamically spray the heat exchange column (21).

5. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, The heat transfer plate (2) is made of diamond-copper composite material, and the heat exchange column (21) is integrally formed with the heat transfer plate (2).

6. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, The heat exchange column (21) has a spiral rib (211) extending spirally along the axial direction on its outer peripheral surface, and the spiral rib (211) is located in the annular gap.

7. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, A flow guide (35) is provided at the upper opening of each of the receiving countersunk holes (32). The flow guide (35) is a trumpet-shaped elastic thin-walled metal tube. Its bottom end is fixedly connected to the inner wall of the orifice of the receiving countersunk hole (32). The top end of the elastic thin-walled metal tube extends into the medium flow gap (31) and folds outward to form a flow guide surface with a circular arc cross section. The end edge of the flow guide surface extends upward to the bottom surface near the heat conduction plate (2).

8. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, A medium outflow pipe (4) is also provided on one side of the encapsulation housing (1) at the position corresponding to the medium flow gap (31).

9. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 7, characterized in that, A plurality of flow guiding ribs (311) are provided on the upper part of the medium flow gap (31) and on the bottom plane of the heat conduction plate (2). The plurality of flow guiding ribs (311) are arranged in an alternating manner between the heat exchange columns, and the surface of the ribs facing the flow guide (35) is recessed to form a C-shaped flow collection groove.

10. The diamond-copper composite microchannel cooling and encapsulation structure according to claim 1, characterized in that, The inner wall of the encapsulation housing (1) is provided with an annular support step for supporting the edge of the heat conduction plate (2). The edge of the heat conduction plate (2) overlaps on the annular support step, and a high-temperature resistant elastic sealing ring is sandwiched between the two.

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