Cooling device and packaging structure for cooling working medium direct injection chip

Abstract

The invention discloses a cooling medium direct injection chip heat dissipation device and a packaging structure, the heat dissipation device comprises a heat dissipation main body arranged on one side, provided with a chip assembly, of a packaging body, and the heat dissipation main body is provided with a cooling medium input channel and a cooling medium output channel; the cooling working medium input channel comprises a micropore array which is arranged at the outlet end of the cooling working medium input channel and right faces the back of the chip assembly, and a heat exchange channel which is communicated with the cooling working medium input channel and the cooling working medium output channel in a sealed mode is arranged between the micropore array and the chip assembly. The heat dissipation body is provided with a heat isolation structure located between the cooling working medium input channel and the cooling working medium output channel. Heat conduction from the backflow cooling working medium to the cooling working medium with the low temperature on the input side can be reduced, and the thermal crosstalk problem is effectively relieved.

Description

Technical Field

[0001] This application relates to the field of chip heat dissipation technology, and in particular to a heat dissipation device and packaging structure for direct injection of cooling working fluid into a chip. Background Technology

[0002] Currently, semiconductor chip heat dissipation solutions mainly include air cooling, cold plate cooling, and microfluidic cooling. Air cooling technology usually needs to work in conjunction with heat sinks and heat plates, and the heat dissipation requirements of high-performance semiconductor chips have approached or even exceeded their heat dissipation capacity limits. Cold plate cooling uses thermal interface materials (TIMs) bonded to the outside of the semiconductor chip package, but the presence of the package cover, TIMs, and other structures significantly increases the path thermal resistance, reducing the heat dissipation efficiency of the cold plate.

[0003] Microfluidic heat dissipation achieves heat transfer through the circulation of cooling medium in microchannels, and has the outstanding advantage of high heat transfer coefficient, making it a potential solution for heat dissipation of high-performance chips. However, existing microfluidic heat dissipation usually suffers from thermal crosstalk between the cooling medium entering and exiting the channel, resulting in low heat dissipation efficiency and affecting the heat dissipation effect of the chip.

[0004] Therefore, how to avoid thermal crosstalk between the cooling medium inlet and outlet channels is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a heat dissipation device and packaging structure for a direct-injection cooling medium chip. By setting a thermal isolation structure between the cooling medium input channel and the cooling medium output channel, heat conduction from the returning cooling medium to the lower-temperature cooling medium on the input side is reduced, effectively alleviating the thermal crosstalk problem.

[0006] To achieve the above objectives, this application provides a heat dissipation device for a chip with direct injection of cooling medium, comprising a heat dissipation body disposed on the side of the package containing the chip assembly. The heat dissipation body is provided with a cooling medium input channel and a cooling medium output channel. The cooling medium input channel includes a micro-hole array disposed at its outlet end and facing the surface of the chip assembly. The micro-hole array and the chip assembly have a heat exchange channel that seals and connects the cooling medium input channel and the cooling medium output channel. The heat dissipation body is also provided with a thermal isolation structure located between the cooling medium input channel and the cooling medium output channel.

[0007] Optionally, the thermal isolation structure includes a vacuum cavity formed in the heat dissipation body, the vacuum cavity at least partially surrounding the outer periphery of the cooling fluid input channel.

[0008] Optionally, the flow cross-sectional area of ​​the heat exchange channel is smaller than the flow cross-sectional area of ​​the cooling medium input channel and the flow cross-sectional area of ​​the cooling medium output channel.

[0009] Optionally, the surface of the micro-hole array facing the chip assembly is provided with a plurality of guide grooves, which extend toward the cooling medium output channel to guide the cooling medium in the heat exchange channel to the cooling medium output channel.

[0010] Optionally, the surface of the micropore array is parallel to the surface of the chip assembly, the working fluid flow direction of the micropore array is perpendicular to the surface of the chip assembly, and the orthographic projection of the micropore array on the chip assembly at least partially covers the surface of the chip assembly.

[0011] Optionally, the heat dissipation body includes an upper body and a lower body that are fixedly connected;

[0012] The cooling working fluid input channel includes a back cavity located in the lower body and a working fluid inlet located in the upper body, wherein the back cavity is located between the micropore array and the working fluid inlet;

[0013] The cooling working fluid output channel includes a return channel located in the lower main body and a working fluid outlet located in the upper main body, wherein the return channel is connected to the heat exchange channel;

[0014] The flow cross-sectional area of ​​the back cavity is larger than the flow cross-sectional area of ​​the working fluid inlet, and the micropore array is distributed on the bottom cavity wall of the back cavity;

[0015] The reflux channels are distributed on the outer periphery of the cavity wall of the back cavity;

[0016] The upper main body is sealed and covered by the reflux channel and the top of the back cavity. The working fluid inlet is one or more circular holes communicating with the back cavity, and the working fluid outlet is one or more circular holes communicating with the reflux channel.

[0017] The vacuum chamber is located in the lower main body, and the upper main body is sealed and covered on the top of the vacuum chamber. Part of the cavity structure of the vacuum chamber is located between the return channel and the back cavity. The bottom and top of the vacuum chamber are flush with the bottom and top of the back cavity, respectively; or, one of the bottom and top of the vacuum chamber is flush with the corresponding side of the back cavity, and the other extends beyond the corresponding side of the back cavity; or, both the bottom and top of the vacuum chamber extend beyond the corresponding side of the back cavity.

[0018] Optionally, the portion of the vacuum cavity located between the reflux channel and the back cavity has its cavity wall parallel to the adjacent channel wall of the reflux channel and parallel to the adjacent cavity wall of the back cavity, and the distance between its cavity wall and the adjacent channel wall of the reflux channel is equal to the distance between its cavity wall and the adjacent cavity wall of the back cavity.

[0019] Optionally, the chip assembly includes a chip and a thermal conductive layer structure disposed on the back side of the chip. The back side of the thermal conductive layer structure is a planar structure, or has turbulence protrusions, or has straight channels.

[0020] Optionally, the number of cooling medium input channels is one or more, and the package is provided with chip components corresponding to each cooling medium input channel;

[0021] In the plurality of cooling working fluid input channels, a cooling working fluid output channel is provided between adjacent cooling working fluid input channels. The cooling working fluid output channel is independently connected to two adjacent cooling working fluid input channels, or two adjacent cooling working fluid input channels share the cooling working fluid output channel.

[0022] A packaging structure includes a package body and a heat dissipation device for direct injection of cooling working fluid into a chip as described above. The package body includes a packaging substrate disposed on a circuit board. The packaging substrate has one or more of the chip components. The packaging substrate also has a reinforcing ring surrounding the chip components. The heat dissipation body is fixedly disposed on the reinforcing ring or the circuit board.

[0023] The beneficial effects of this application are that a cooling medium circulation channel is formed by the cooling medium input channel, the heat exchange channel, and the cooling medium output channel. The cooling medium is sprayed from a micro-jet source at the micro-hole array, forming a uniform cooling field on the entire heat-generating surface of the chip assembly, effectively removing the heat from the chip assembly. Furthermore, by arranging a thermal isolation structure between the cooling medium input channel and the cooling medium output channel, the low-temperature working medium is prevented from being heated by the high-temperature working medium in the cooling medium output channel. This allows the low-temperature working medium to impact the chip at the lowest initial temperature, maximizing the heat exchange capacity of the cooling medium in each cycle and ensuring the heat dissipation efficiency of the heat dissipation device. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the heat dissipation device structure for the direct injection cooling medium chip provided in the embodiments of this application;

[0026] Figure 2 An exploded view of the heat dissipation device for the direct-injection cooling medium chip provided in the embodiments of this application;

[0027] Figure 3 for Figure 1 Sectional view of AA;

[0028] Figure 4 for Figure 3 BB section view;

[0029] Figure 5 This is a schematic diagram of the lower main structure provided in an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of the first thermally conductive layer structure provided in the embodiments of this application;

[0031] Figure 7 This is a cross-sectional view of the first thermally conductive layer structure provided in the embodiments of this application;

[0032] Figure 8 This is a schematic diagram of the second thermally conductive layer structure provided in the embodiments of this application;

[0033] Figure 9 This is a cross-sectional view of the second thermally conductive layer structure provided in the embodiments of this application;

[0034] Figure 10 This is a schematic diagram of the third thermally conductive layer structure provided in the embodiments of this application;

[0035] Figure 11 This is a cross-sectional view of the third thermally conductive layer structure provided in the embodiments of this application;

[0036] Figure 12 This is a schematic diagram of the packaging structure provided in an embodiment of this application;

[0037] Figure 13 for Figure 12 CC section view;

[0038] Figure 14 for Figure 13 Enlarged view of point A in the middle.

[0039] In the diagram: 1 - Circuit board;

[0040] 2-Package body; 21-Packaging substrate; 22-Reinforcing ring; 23-Chip assembly; 24-Solder ball; 25-Adhesive; 26-Fill material; 231-Chip; 232-Thermal conductive layer structure; 2321-Planar structure; 2322-Breakthrough protrusion; 2323-Straight channel;

[0041] 3-Heat dissipation body; 31-Upper body; 32-Lower body; 33-Cooling medium input channel; 34-Vacuum chamber; 35-Cooling medium output channel; 36-Guide groove; 37-Heat exchange channel; 331-Working medium inlet; 332-Back cavity; 333-Micropore array; 351-Working medium outlet; 352-Recirculation channel;

[0042] 4-Fasteners; 41-Bolts; 42-Reinforcing plates;

[0043] 5-Sealing ring. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] It should be noted that in this embodiment, the orientation or positional relationship indicated by terms such as "upper," "lower," "front," and "rear" is based on the orientation or positional relationship shown in the accompanying drawings. It is used only for the convenience of describing this application and for simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application. Furthermore, "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Please refer to Figures 1 to 3 In this embodiment, a heat dissipation device for direct injection of cooling medium into a chip is provided. The device includes a heat dissipation body 3 arranged on the side of the package 2 with chip assembly 23. The heat dissipation body 3 serves as the supporting skeleton and functional carrier of the entire device and needs to provide mechanical support and airflow path. The heat dissipation device as a whole has high stability and can be made of metal or non-metal materials such as aluminum alloy, copper, and high-temperature resistant resin, but it must be compatible with the cooling medium used. The cooling medium can be pressurized deionized water, propylene glycol solution, silicone oil, fluorinated liquid, etc.

[0048] The heat dissipation body 3 is provided with a cooling medium input channel and a cooling medium output channel 35. Depending on the material of the heat dissipation body 3, the way the channels and cavities are processed on the heat dissipation body 3 will also be different. If metal materials such as copper or aluminum alloy are used, CNC machining can be used in conjunction with vacuum brazing / diffusion welding to manufacture and assemble. If non-metallic materials such as high temperature resin are used, 3D printing can be selected for one-piece molding.

[0049] The cooling medium input channel 33 includes a micro-hole array 333 arranged at its outlet end and facing the heating surface of the chip assembly 23. Specifically, the micro-hole array 333 faces the heating surface on the back of the chip assembly 23. The micro-holes in the micro-hole array 333 are arranged in a regular array to ensure coverage of the entire heating area on the back of the chip assembly 23. Each micro-hole acts as an independent micro-nozzle, directly guiding the cooling medium to the heating part of the chip assembly 23. The size and distribution density of the micro-holes can be set according to the actual heat dissipation situation. The specific configuration of the micro-holes can adopt a conical or cylindrical structure. However, considering that although a conical inlet can reduce flow loss, it is difficult to process; while a cylindrical inlet is easy to process but has a significant inlet effect, a stepped composite structure of conical and cylindrical shapes can be adopted.

[0050] The micro-hole array 333 and the chip assembly 23 have a heat exchange channel 37 that seals and connects the cooling medium input channel 33 and the cooling medium output channel 35. The heat exchange channel 37 is the core area for heat exchange between the cooling medium and the back surface of the chip assembly 23. After the cooling medium impacts the back of the chip assembly 23 through the micro-hole array 333, it will flow through the heat exchange channel 37 to the cooling medium output channel 35 and then flow out through the cooling medium output channel 35, thus forming a circulation channel for the cooling medium.

[0051] It should be noted that when the heat dissipation body 3 and the package 2 are assembled, in order to ensure the sealing of the above-mentioned circulation channel, a sealing ring 5 needs to be set between the heat dissipation body 3 and the package 2. The sealing ring 5 needs to surround the heat exchange channel 37 of the cooling medium input channel 33 and the cooling medium output channel 35. Similarly, the material of the sealing ring 5 also needs to be compatible with the cooling medium to avoid the two reacting and affecting the sealing effect.

[0052] The heat dissipation body 3 is provided with a thermal isolation structure located between the cooling medium input channel 33 and the cooling medium output channel 35. The thermal isolation structure can be a heat insulation material filled inside the heat dissipation body 3, such as aerogel or rock wool. The thermal isolation structure can also be a vacuum cavity 34 structure opened on the heat dissipation body 3, which can effectively block the transfer of heat between the cooling medium input channel 33 and the cooling medium output channel.

[0053] As can be seen, this application forms a cooling medium circulation channel through the cooling medium input channel 33, the heat exchange channel 37, and the cooling medium output channel 35. The cooling medium forms a micro-jet source at the micro-hole array 333, forming a uniform cooling field on the back of the entire chip assembly 23 to effectively remove the heat from the chip assembly 23. Furthermore, through the thermal isolation structure arranged between the cooling medium input channel 33 and the cooling medium output channel 35, the low-temperature working medium is prevented from being heated by the high-temperature working medium in the cooling medium input channel 33 and the high-temperature working medium in the cooling medium output channel 35. This allows the low-temperature working medium to impact the chip 231 at the lowest initial temperature, maximizing the heat exchange capacity of the cooling medium in each cycle and ensuring the heat dissipation efficiency of the heat dissipation device.

[0054] In this embodiment, the thermal isolation structure adopts a vacuum cavity 34 structure opened in the heat dissipation body 3. Utilizing the extremely low thermal conductivity of vacuum, heat is difficult to conduct from the cooling medium output channel 35 through the heat dissipation body 3 to the cooling medium in the cooling medium input channel 33, ensuring the heat dissipation efficiency of the cooling medium. In some embodiments, a layer of thermal insulation material such as aerogel can be nested in the vacuum cavity 34. Through the synergistic effect of multi-level thermal insulation mechanisms, the thermal insulation effect of the thermal isolation structure can be ensured; alternatively, a high-reflectivity metal layer (such as aluminum or silver) can be plated on the inner wall of the vacuum cavity 34, which can significantly reduce the radiative heat transfer effect.

[0055] Furthermore, the vacuum cavity 34 is at least partially arranged around the outer periphery of the cooling medium input channel 33, so that the thermal insulation structure forms a continuous and uninterrupted heat insulation layer around the outer periphery of the cooling medium input channel 33, preventing heat from being conducted or radiated into the cooling medium input channel 33 from any angle. This means that the cooling medium that carries away heat from the back of the chip assembly 23, after entering the cooling medium output channel 35, has its heat strictly confined within the cooling medium output channel 35 and cannot "flow back" to the cooling medium input channel 33.

[0056] In some embodiments, the flow cross-sectional area of ​​the heat exchange channel 37 is smaller than that of the cooling medium inlet channel 33 and the cooling medium outlet channel 35. According to fluid mechanics principles, under a constant flow rate, a decrease in flow cross-sectional area leads to an increase in flow velocity. Since the cross-sectional area of ​​the heat exchange channel 37 is smaller than that of the cooling medium inlet channel 33 and the cooling medium outlet channel 35, the flow velocity of the cooling medium within the heat exchange channel 37 is significantly increased. This increased velocity disrupts the thermal boundary layer, improving convective heat transfer efficiency, especially for microscale flows. Furthermore, the high flow velocity shortens the residence time of the cooling medium within the heat exchange channel 37, ensuring that the high-temperature medium is quickly carried away to the cooling medium outlet channel 35, while the low-temperature medium is continuously replenished, reducing thermal saturation.

[0057] Based on the above embodiments, the cooling medium input channel 33 and the cooling medium output channel 35 can be made to have a larger cross-sectional area, thereby reducing the flow resistance of these parts, allowing the external pumping system to operate at a lower pressure and reducing energy consumption.

[0058] In addition, the cross-sectional area of ​​the heat exchange channel 37 can be designed in a gradually changing form (such as a conical contraction) to optimize the velocity distribution and pressure gradient; or a periodic expansion and contraction structure (such as a corrugated wall) can be set in the heat exchange channel 37 to enhance turbulent mixing by generating eddies, thereby further improving the heat exchange effect.

[0059] Please refer to Figure 4 A plurality of guide grooves 36 are provided on the surface of the micropore array 333 facing the chip assembly 23. The guide grooves 36 extend toward the cooling medium output channel 35 to guide the cooling medium to the cooling medium output channel 35, thereby reducing flow resistance and enhancing the heat transfer efficiency between the chip assembly 23 and the cooling medium. By setting the guide grooves 36, a directional flow channel can be formed in the heat exchange channel 37, avoiding local stagnation caused by disordered diffusion of the cooling medium on the surface of the chip assembly 23, improving the cooling medium renewal rate on the surface of the chip assembly 23, and ensuring heat exchange efficiency.

[0060] Based on this, multiple guide grooves 36 can be parallel to each other and parallel to the long or short side of the chip assembly 23, and a protrusion structure is formed between two adjacent guide grooves 36. The micropores in the micro-hole array 333 can correspond to the protrusion structure.

[0061] The surface of the microvia array 333 is parallel to the back surface of the chip assembly 23, ensuring a constant distance from the outlet of each microvia to the surface of the chip assembly 23. This results in a relatively uniform flow resistance for each microvia, and the parallel surface allows the cooling medium to be uniformly ejected from all the microvias. This fundamentally avoids the chaotic situation caused by differences in distance, where some microvias flow faster than others. If the surface of the microvia array 333 is not parallel to the surface of the chip assembly 23, microvias on one side will be closer to the chip assembly 23, resulting in a faster flow rate and over-cooling, while those on the other side will be farther away, resulting in a slower flow rate and insufficient cooling. The parallel design ensures that every point on the back of the chip assembly 23 is under nearly identical heat transfer conditions, eliminating the problem of insufficient local heat transfer in the chip assembly 23.

[0062] The working fluid of the micro-hole array 333 flows perpendicular to the back surface of the chip assembly 23. The vertical impact can penetrate the "thermal boundary layer" formed by heat accumulation on the surface of the chip assembly 23 most directly and powerfully. Its heat transfer intensity is far greater than that of oblique impact or parallel flow. After the vertical impact, the cooling working fluid diffuses evenly in all directions and can be captured and guided by the guide groove 36, avoiding disorderly splashing and retention of the working fluid on the surface of the chip 231.

[0063] The orthographic projection of the micro-via array 333 onto the chip assembly 23 at least covers the back surface of the chip assembly 23, ensuring that the heat-generating area on the back of the chip assembly 23 can be completely covered by the micro-via array 333, avoiding any cooling blind spots. Combined with the aforementioned guide groove 36 structure, the cooling medium on the surface of the chip assembly 23 can flow directly to the cooling medium output channel 35 under the action of the guide groove 36, preventing the retention of cooling medium at any location on the back surface of the chip assembly 23.

[0064] The heat dissipation body 3 of this application includes an upper body 31 and a lower body 32 fixedly connected. The cooling working fluid input channel 33 includes a back cavity 332 provided in the lower body 32 and a working fluid inlet 331 provided in the upper body 31. The back cavity 332 is located between the micropore array 333 and the working fluid inlet 331. The cooling working fluid output channel 35 includes a return channel 352 provided in the lower body 32 and a working fluid outlet 351 provided in the upper body 31. The return channel 352 is connected to the heat exchange channel 37.

[0065] The split design of the upper body 31 and the lower body 32 significantly reduces the processing difficulty of the heat dissipation body 3. For example, the lower body 32 can be used for processing complex structures (such as the back cavity 332, the return channel 352, and the vacuum cavity 34), and CNC machining, 3D printing, and other processing methods can be selected according to different materials. The upper body 31, on the other hand, undertakes simple processing methods such as the working fluid inlet 331 and the working fluid outlet 351. The working fluid inlet 331 is one or more round holes communicating with the back cavity 332, and the working fluid outlet 351 is one or more round holes communicating with the return channel 352. Through the sealed and fixed connection between the upper body 31 and the lower body 32, the upper body 31 covers the top of the return channel 352 and the back cavity 332, thereby forming a closed cavity structure on the top of the return channel 352 and the back cavity 332. Similarly, the vacuum chamber 34 is located on the lower body 32, and the upper body 31 is sealed and covered on the top of the vacuum chamber 34. By drawing a vacuum, the vacuum chamber 34 forms a sealed cavity structure.

[0066] Furthermore, the back cavity 332 has a rectangular cavity structure; please refer to [reference needed]. Figure 5 The flow cross-sectional area of ​​the rectangular cavity is larger than that of the working fluid inlet 331, while the micro-hole array 333 is distributed on the bottom cavity wall of the back cavity 332. The cross-sectional area of ​​the back cavity 332 is larger than that of the upstream working fluid inlet 331. After entering the back cavity 332, the high-pressure cooling working fluid from the working fluid inlet 331 is fully diffused and mixed. The cooling working fluid forms a stable and uniform pressure field in the back cavity 332, providing a common and stable working pressure source for the bottom micro-hole array 333, so as to ensure that the micro-hole array 333 can eject cooling working fluid with the same pressure and flow rate.

[0067] Please refer to Figure 5The return channels 352 are distributed on the outer periphery of the cavity wall of the back cavity 332. Specifically, the return channels 352 are rectangular channels. In this embodiment, the return channels 352 are set in the form of two independent channels, that is, the two independent return channels 352 correspond to the two opposite sidewalls of the back cavity 332 respectively. Specifically, the two return channels 352 correspond to the two long sides of the back cavity 332 respectively. Based on this, the cooling medium that diffuses radially in all directions after being vertically impacted by the micro-hole array 333 onto the surface of the chip 231 has the shortest and most direct outflow path to be the two sides perpendicular to the long side of the back cavity 332. This allows the cooling medium to enter the cooling medium output channel 35 with the shortest path and the lowest flow resistance, ensuring that the heated cooling medium can quickly leave the heat exchange channel 37.

[0068] Since the vacuum cavity 34 surrounds the outer periphery of the back cavity 332, part of the cavity structure of the vacuum cavity 34 is located between the return channel 352 and the back cavity 332. Furthermore, the bottom and top of the vacuum cavity 34 are flush with the bottom and top of the back cavity 332, ensuring that the shortest straight heat conduction path from the return channel 352 is 100% cut off.

[0069] Furthermore, one of the bottom and top of the vacuum cavity 34 is flush with the corresponding side of the back cavity 332, while the other extends beyond the corresponding side of the back cavity 332; or, both the bottom and top of the vacuum cavity 34 extend beyond the corresponding side of the back cavity 332, which can further improve the heat insulation effect between the back cavity 332 and the return channel 352. Furthermore, when the top and / or bottom of the vacuum cavity 34 extends beyond the corresponding side of the back cavity 332, the extending end of the vacuum cavity 34 can also extend along the top or bottom surface of the back cavity 332, thereby forming an L-shaped or U-shaped vacuum cavity 34 structure, which can block heat conduction from the upper body 31 to the back cavity 332, and can also block some of the heat in the heat exchange channel 37 from conducting to the back cavity 332.

[0070] In some embodiments, the partial vacuum cavity 34 located between the return channel 352 and the back cavity has a cavity wall parallel to the adjacent channel wall of the return channel 352 and parallel to the adjacent cavity wall of the back cavity 332, and the distance between its cavity wall and the adjacent channel wall of the return channel 352 is equal to the distance between its cavity wall and the adjacent cavity wall of the back cavity 332. The cavity wall of the vacuum cavity 34 being parallel to the return channel 352 and the back cavity 332 ensures that the heat flow path remains perpendicular to the vacuum cavity 34 when the heat flow passes through the thermal isolation structure, eliminating the heat flow focusing effect of conventional curved cavity walls.

[0071] Please refer to Figure 6The chip assembly 23 can be a single heat source chip 231, or it can include the chip 231 and a thermally conductive layer structure 232 disposed on the back of the chip 231. This thermally conductive layer structure 232 includes, but is not limited to, functional microstructure layers such as polycrystalline diamond, diamond composite materials, or diamond-like films. Integration schemes between the thermally conductive layer structure 232 and the chip 231 include, but are not limited to, bonding, welding, and electroplating processes. Integrating the thermally conductive layer structure 232 on the back of the chip 231 can significantly enhance the heat dissipation performance of the chip assembly 23, especially suitable for operating conditions with localized high heat flux density hotspots. Simultaneously, under heat dissipation methods such as direct injection of cooling fluid, this structure can also effectively improve the impact resistance, wear resistance, and long-term operational reliability of the chip 231.

[0072] In this embodiment, polycrystalline diamond is selected as the material for the thermal conductive layer structure 232 and integrated onto the back side of the chip 231. The back side of the thermal conductive layer structure 232 is a planar structure 2321, as shown in the figure. Figure 6 and Figure 7 As shown. Due to the extremely high thermal conductivity of diamond, the heat generated by chip 231 can be rapidly conducted within it and diffused in-plane. For localized hot spots with high heat flux density in chip 231, the heat transferred to the diamond layer can be quickly dispersed to a larger area, which is equivalent to achieving an effective reduction in heat flux density in the thermally conductive layer structure 232, thereby enabling the heat dissipation device to cope with higher localized thermal loads.

[0073] In addition, diamond materials also possess high hardness and high wear resistance. Under direct injection of cooling fluid, compared to bulk silicon materials, the diamond layer can significantly improve the mechanical strength and durability of the chip 231 surface, thereby enhancing the long-term reliability of the heat dissipation device under harsh operating conditions and extending its service life.

[0074] In some embodiments, a thermal conductive layer structure 232 and a turbulence protrusion 2322 structure are integrated on the back side of the chip 231. Please refer to [reference needed]. Figure 8 and Figure 9 The turbulence protrusion 2322 can be a turbulence pillar. The turbulence pillar microstructure can be fabricated on the thermally conductive layer structure 232 first, and then integrated onto the back side of the chip 231; alternatively, the thermally conductive layer structure 232 can be integrated onto the back side of the chip 231 first, and then the turbulence pillar microstructure can be fabricated on the thermally conductive layer structure 232. The material of the thermally conductive layer structure 232 and its integration scheme with the chip 231 can be referred to the above embodiments, and will not be repeated here. The processing methods for the turbulence pillar microstructure include, but are not limited to, CNC machining, DRIE etching, electroplating, etc.

[0075] By integrating a composite structure of a thermally conductive layer structure 232 and a turbulence protrusion 2322 on the back of the chip 231, a synergistic improvement in heat dissipation performance and reliability is achieved. The turbulence protrusion 2322 structure significantly increases the convective heat transfer area of ​​the chip 231's heat dissipation surface and enhances the fluid turbulence of the cooling medium. While utilizing the high hardness and high wear resistance of the thermally conductive layer structure 232 itself to improve the impact resistance and long-term reliability of the chip 231, it further optimizes the overall heat dissipation effect by enhancing convective heat transfer.

[0076] In some embodiments, a composite structure of a thermally conductive layer structure 232 and a flat channel 2323 is integrated on the back side of the chip 231. Please refer to... Figure 10 and Figure 11 Alternatively, a straight channel 2323 can be fabricated on the thermally conductive layer structure 232 first, and then the thermally conductive layer structure 232 with the straight channel 2323 can be integrated onto the back side of the chip 231; or the thermally conductive layer structure 232 can be integrated onto the back side of the chip 231 first, and then the straight channel 2323 can be fabricated on the thermally conductive layer structure 232. The material of the thermally conductive layer structure 232, the integration scheme with the chip 231, and the processing method of the straight channel 2323 can be referred to the above embodiments, and will not be repeated here.

[0077] By integrating a composite structure of a thermally conductive layer structure 232 and a straight channel 2323 on the back of the chip 231, a synergistic improvement in heat dissipation performance and reliability is achieved. The straight channel 2323 structure significantly increases the convective heat transfer area of ​​the heat dissipation surface and guides the flow of the cooling fluid, reducing flow resistance. While utilizing the high hardness and high wear resistance of the thermally conductive layer structure 232 itself to improve the impact resistance and long-term reliability of the chip 231, the overall heat dissipation effect is further optimized.

[0078] It should be noted that the number of cooling medium input channels 33 in the heat dissipation device of this application is one or more, and the package 2 is provided with chip components 23 corresponding to each cooling medium input channel 33. For example, a cooling medium input channel 33 can be arranged on a heat dissipation device, and a heat source chip 231 is provided on the package 2 accordingly. Alternatively, multiple cooling medium input channels 33 can be arranged on a heat dissipation device at the same time, and multiple heat source chips 231 that can be provided on the package 2 accordingly, so as to ensure that each chip component 23 can correspond to the cooling medium input channel 33.

[0079] Furthermore, when multiple heat source chips 231 are arranged on the package 2, a configuration can be adopted in which multiple heat dissipation devices correspond one-to-one with each chip 231. Please refer to [reference needed]. Figure 12When the package 2 is a large-size, multi-chip 231 fan-out package module, the package 2 includes a large number of chips 231. If the heat dissipation device has only one or two cooling medium input channels 33, it is obviously unable to meet the heat dissipation of a large number of chips 231. Therefore, multiple heat dissipation devices can be set up in an array to ensure that each chip 231 can correspond to the cooling medium input channel 33 of the heat dissipation device.

[0080] When the heat dissipation device has multiple cooling fluid input channels 33, please refer to... Figure 3 A cooling medium output channel 35 is provided between adjacent cooling medium input channels 33, and two adjacent cooling medium input channels 33 can share the cooling medium output channel 35 between them; or there are two cooling medium output channels 35 between two adjacent cooling medium input channels 33, and the two cooling medium input channels 33 can be independently connected to the two cooling medium output channels 35 between them. For a technical solution with only one cooling medium input channel 33 on a heat dissipation device, please refer to... Figure 13 and 14 The cooling medium input channel 33 can be connected to the cooling medium output channels 35 on both sides, while the channels between adjacent heat dissipation devices are independent of each other and will not affect each other.

[0081] This application also provides a packaging structure, which includes a package body 2 and a heat dissipation device for the direct injection of cooling working fluid into the chip 231 as described above. The package body 2 includes a packaging substrate 21 disposed on a circuit board 1, and solder balls 24 are used for electrical connection between the packaging substrate 21 and the circuit board 1. The packaging substrate 21 is provided with one or more chip components 23.

[0082] Please refer to Figure 2 and Figure 3 The packaging substrate 21 has a reinforcing ring 22 surrounding the chip assembly 23. The reinforcing ring 22 can be made of copper and is machined by CNC or stamped to enhance the overall rigidity of the packaging substrate 21. The heat dissipation body 3 abuts against the reinforcing ring 22. Specifically, the lower body 32 of the heat dissipation body 3 abuts against the reinforcing ring 22, while the upper body 31 extends beyond the lower body 32 on both sides, and fastening holes are formed in the extended parts. Correspondingly, fastening holes are set on the circuit board 1. The heat dissipation body 3 is fixed to the circuit board 1 by fasteners 4, thereby realizing the fixed connection between the heat dissipation body 3 and the reinforcing ring 22, as well as the sealed connection between the heat dissipation body 3 and the package 2. In addition, a reinforcing plate 42 can be set on the side of the circuit board 1 away from the heat dissipation body 3. The reinforcing plate 42 also has corresponding fastening holes to provide mechanical support on the circuit board 1 and prevent the fastening force of the bolts 41 and nuts during assembly from damaging the components.

[0083] Fastener 4 is a bolt 41 and nut structure. Bolt 41 passes through fastening holes arranged on the upper body 31, circuit board 1 / main board and reinforcing plate 42 to achieve sealed fastening assembly of heat dissipation device, sealing ring 5, package 2 and circuit board 1 / main board.

[0084] Please refer to Figure 13 The packaging substrate 21 has a reinforcing ring 22 surrounding the chip assembly 23. The heat dissipation body 3 abuts against the reinforcing ring 22. Specifically, the upper body 31 of the heat dissipation body 3 extends beyond the lower body 32 on both sides, and the extended part of the upper body 31 abuts against the reinforcing ring 22 and is fixedly connected by fasteners 4. At the same time, the reinforcing ring 22 is fixed to the packaging substrate 21 by adhesive 25. Similarly, the heat dissipation device can be locked onto the package body 2 by fasteners 4, thus achieving a sealed connection between the package body 2 and the heat dissipation device. In addition, when there are multiple chip assemblies 23 on the packaging substrate 21, a filling material 26 can be provided between the chip assemblies 23. The sealing ring 5 on the heat dissipation body 3 can seal against the filling material 26, thereby ensuring the sealing effect of both.

[0085] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0086] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A heat dissipation device for directly injecting cooling working fluid into a chip, characterized in that, The package includes a heat dissipation body (3) arranged on the side of the package (2) with the chip assembly (23). The heat dissipation body (3) is provided with a cooling medium input channel (33) and a cooling medium output channel (35). The cooling medium input channel (33) includes a micro-hole array (333) arranged at its outlet end and facing the surface of the chip assembly (23). The micro-hole array (333) and the chip assembly (23) have a heat exchange channel (37) that seals and connects the cooling medium input channel (33) and the cooling medium output channel (35). The heat dissipation body (3) is also provided with a thermal isolation structure located between the cooling medium input channel (33) and the cooling medium output channel (35).

2. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 1, characterized in that, The thermal isolation structure includes a vacuum cavity (34) formed in the heat dissipation body (3), the vacuum cavity (34) being at least partially surrounding the outer periphery of the cooling working fluid input channel (33).

3. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 1, characterized in that, The flow cross-sectional area of ​​the heat exchange channel (37) is smaller than the flow cross-sectional area of ​​the cooling medium input channel (33) and the flow cross-sectional area of ​​the cooling medium output channel (35).

4. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 1, characterized in that, The micro-hole array (333) has a plurality of guide grooves (36) on the surface facing the chip assembly (23). The guide grooves (36) extend toward the cooling medium output channel (35) to guide the cooling medium in the heat exchange channel (37) to the cooling medium output channel (35).

5. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 1, characterized in that, The surface of the micropore array (333) is parallel to the surface of the chip assembly (23), the working fluid flow direction of the micropore array (333) is perpendicular to the surface of the chip assembly (23), and the orthographic projection of the micropore array (333) on the chip assembly (23) at least partially covers the surface of the chip assembly (23).

6. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 2, characterized in that, The heat dissipation body (3) includes an upper body (31) and a lower body (32) that are fixedly connected. The cooling working fluid input channel (33) includes a back cavity (332) provided in the lower body (32) and a working fluid inlet (331) provided in the upper body (31). The back cavity (332) is located between the micropore array (333) and the working fluid inlet (331). The cooling working fluid output channel (35) includes a return channel (352) located in the lower body (32) and a working fluid outlet (351) located in the upper body (31). The return channel (352) is connected to the heat exchange channel (37). The flow cross-sectional area of ​​the back cavity (332) is larger than the flow cross-sectional area of ​​the working fluid inlet (331), and the micropore array (333) is distributed on the bottom cavity wall of the back cavity (332). The reflux channel (352) is distributed on the outer periphery of the cavity wall of the back cavity (332); The upper body (31) is sealed and covered on the top of the reflux channel (352) and the back cavity (332). The working fluid inlet (331) is one or more round holes communicating with the back cavity (332), and the working fluid outlet (351) is one or more round holes communicating with the reflux channel (352). The vacuum chamber (34) is located on the lower body (32), and the upper body (31) is sealed and covered on the top of the vacuum chamber (34). Part of the cavity structure of the vacuum chamber (34) is located between the return channel (352) and the back cavity (332). The bottom and top of the vacuum chamber (34) are flush with the bottom and top of the back cavity (332), respectively; or, one of the bottom and top of the vacuum chamber (34) is flush with the corresponding side of the back cavity (332), and the other extends beyond the corresponding side of the back cavity (332); or, the bottom and top of the vacuum chamber (34) both extend beyond the corresponding side of the back cavity (332).

7. The heat dissipation device for direct injection of cooling working fluid into a chip according to claim 6, characterized in that, The portion of the vacuum cavity (34) located between the return channel (352) and the back cavity (332) has its cavity wall parallel to the adjacent channel wall of the return channel (352) and parallel to the adjacent cavity wall of the back cavity (332), and the distance between its cavity wall and the adjacent channel wall of the return channel (352) is equal to the distance between its cavity wall and the adjacent cavity wall of the back cavity (332).

8. The heat dissipation device for direct injection of cooling working fluid into the chip according to claim 1, characterized in that, The chip assembly (23) includes a chip (231) and a heat-conducting layer structure (232) disposed on the back side of the chip (231). The back side of the heat-conducting layer structure (232) is a planar structure (2321), or has a turbulence protrusion (2322), or has a straight channel (2323).

9. The heat dissipation device for direct injection of cooling working fluid into a chip according to claim 1, characterized in that, The number of cooling medium input channels (33) is one or more, and the package (2) is provided with chip components (23) corresponding to the cooling medium input channels (33). In the plurality of cooling working fluid input channels (33), a cooling working fluid output channel (35) is provided between adjacent cooling working fluid input channels (33). The cooling working fluid output channel (35) is independently connected to two adjacent cooling working fluid input channels (33), or, two adjacent cooling working fluid input channels (33) share the cooling working fluid output channel (35).

10. A packaging structure, characterized in that, The package includes a package body (2) and a heat dissipation device for a direct-injection cooling medium chip as described in any one of claims 1-9. The package body (2) includes a package substrate (21) disposed on a circuit board (1). The package substrate (21) is provided with one or more of the chip components (23). The package substrate (21) is also provided with a reinforcing ring (22) surrounding the chip components (23). The heat dissipation body (3) is fixedly disposed on the reinforcing ring (22) or the circuit board (1).

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