3D vapor chamber for small area chip cooling

Abstract

The utility model discloses a 3D steam chamber for small area chip heat dissipation, including upper cover, lower cover, upper cover and lower cover sealed connection, form sealed cavity, sealed cavity is divided into non heat source area and with small area chip corresponding heat source area, and the heat source area is equipped with a plurality of copper column, and the lower cover of heat source area is equipped with a plurality of microneedle, and the surface of lower cover of sealed cavity is equipped with lower cover capillary, and the lower surface of upper cover of sealed cavity is equipped with upper cover capillary, and the copper column outer periphery is equipped with copper column capillary, and the microneedle surface is equipped with microneedle capillary, and the upper and lower ends of copper column capillary are overlapped with upper cover capillary and lower cover capillary respectively, and microneedle capillary is overlapped with lower cover capillary. The utility model realizes the big reduction of thermal resistance, satisfies the heat dissipation demand of superhigh heat flow density chip, is especially applicable to the miniature electronic equipment heat dissipation scene of needing low thermal resistance, high liquid volume and high heat transfer capacity.

Description

Technical Field

[0001] This utility model relates to the field of heat sink technology, and in particular to a 3D vapor chamber for heat dissipation of small-area chips. Background Technology

[0002] As chip integration continues to increase, power density also rises, especially for small-area chips (such as CPU cores and GPU memory chips). These chips have concentrated heat sources and extremely high heat flux densities (reaching over 500W / cm²), placing stringent demands on thermal resistance control in heat dissipation systems. 3D vapor chambers (3DVCs), as highly efficient phase-change heat dissipation components, achieve rapid heat transfer through the evaporation-condensation cycle of the working fluid and have been widely used in chip heat dissipation. However, existing 3DVCs still have the following technical limitations in small-area chip heat dissipation scenarios: 1. Limited thermal resistance reduction: The contact area between the heat source of the small chip and the evaporation surface of the 3DVC is limited. The heat conduction path of the traditional single capillary (such as copper mesh, sintered copper powder) is long, and the contact thermal resistance is superimposed with the thermal resistance of the capillary itself, making it difficult to further reduce the overall thermal resistance and failing to meet the heat dissipation requirements of chips with ultra-high heat flux density. 2. Insufficient working fluid inventory: To accommodate the size limitations of microelectronic devices, the external dimensions of 3DVC need to be strictly controlled. Traditional chambers are mostly single cavities or simple layered structures with limited liquid storage space. The working fluid inventory is low, which can lead to the inability to replenish the working fluid in time after evaporation, causing the risk of "burning dry" and limiting the stability of heat dissipation. 3. Maximum heat transfer capacity (Qmax) bottleneck: The recirculation channels of existing 3DVCs are mostly single-path or simple branched structures with fixed recirculation area and limited heat transfer efficiency of the channel wall, resulting in insufficient recirculation rate after the working fluid condenses, making it difficult to break through Qmax and unable to match the heat transfer requirements of high-power chips.

[0003] 4. The single reflux channel requires long-distance horizontal reflux of condensate, resulting in a large pressure drop. Existing 3DVC multi-focus "large-area uniform temperature" has insufficient research on small-area heat sources and has not yet solved the dual contradiction of "low thermal resistance + high reflux".

[0004] Therefore, developing a 3DVC structure that can reduce thermal resistance, increase cavity water storage capacity, and enhance Qmax under small-area chip heat sources has become a key technical requirement in the current chip heat dissipation field. Utility Model Content

[0005] The technical problem to be solved by this utility model embodiment is to provide a 3D vapor chamber for heat dissipation of small-area chips, so as to achieve continuous and efficient heat dissipation of small-area chips.

[0006] To address the aforementioned technical problems, this utility model proposes a 3D vapor chamber for heat dissipation of small-area chips, comprising an upper cover plate and a lower cover plate, which are sealed together to form a closed cavity. The closed cavity is divided into a non-heat source area and a heat source area corresponding to the small-area chip. The heat source area is provided with several copper pillars, and the lower cover plate of the heat source area is provided with several microneedles. The surface of the lower cover plate inside the closed cavity is provided with a lower cover capillary, and the lower surface of the upper cover plate inside the closed cavity is provided with an upper cover capillary. Copper pillar capillary is provided around the copper pillars, and microneedle capillary is provided on the surface of the microneedles. The upper and lower ends of the copper pillar capillary overlap with the upper cover capillary and the lower cover capillary, respectively, and the microneedle capillary overlaps with the lower cover capillary.

[0007] Furthermore, the surface of the lower cover plate in the heat source area is provided with multiple sets of micro grooves, and the micro needles are correspondingly located in the area between the micro grooves of the lower cover plate, and the multiple micro needles form a micro needle array.

[0008] Furthermore, a copper pipe is provided on the upper cover plate corresponding to the heat source area, and a copper pipe capillary is provided inside the copper pipe. A bridge capillary is provided below the copper pipe in the heat source area. The bridge capillary is located between two copper pillars, and the two ends of the bridge capillary overlap with the copper pillar capillary on the two copper pillars respectively. The bridge capillary overlaps with the copper pipe capillary inside the copper pipe above.

[0009] Furthermore, the bridge capillary is provided with copper tube grooves for fixing copper tubes.

[0010] Furthermore, the surfaces of the lower cover capillary, upper cover capillary, copper column capillary, micro needle capillary and / or bridge capillary within the sealed cavity are provided with micro-nano groove structures, each composed of several micro-nano grooves.

[0011] Furthermore, the depth of the micro-nano grooves ranges from 5μm to 10μm, and the spacing between the micro-nano grooves ranges from 10μm to 15μm.

[0012] Furthermore, the micro-nano groove structure is prepared by electrochemical corrosion or integral forging.

[0013] Furthermore, the diameter of the microneedles ranges from 0.1 mm to 0.5 mm, and the height ranges from 0.1 mm to 1.0 mm.

[0014] Furthermore, the microneedles, microneedle capillaries, microgrooves, and the lower capillary of the heat source area constitute a composite capillary core, and the ratio of the total area of ​​the composite capillary core to the heat source area of ​​the small-area chip is (1.2-1.5):1.

[0015] Furthermore, several support columns are provided on the lower cover plate of the non-heat source area.

[0016] The beneficial effects of this utility model are as follows: 1. Significantly reduced thermal resistance: The composite capillary core structure of the microneedle, lower cover capillary and copper column capillary of this utility model shortens the heat conduction path and enhances the wettability of the working fluid, achieving a significant reduction in thermal resistance in the small area of ​​chip heat source region, meeting the heat dissipation requirements of ultra-high heat flux density chips. 2. Significantly increased water storage capacity: The three-dimensional bridge capillary connection of this utility model connects the copper column capillary and the copper tube capillary, which effectively expands the liquid storage space without increasing the external volume, avoids the risk of the working fluid "burning dry", and improves heat dissipation stability. 3. Qmax Breakthrough: The recirculation channel of this utility model realizes multi-stage diversion and re-convergence, and the surface of the recirculation channel is provided with micro-nano groove structure, realizing a dual improvement in recirculation area and heat transfer coefficient, pushing the maximum heat transfer capacity to a new high, matching the heat transfer requirements of high-power chips. 4. Strong compatibility: The compact structural design can be adapted to small-area chips of different sizes, and the manufacturing process is mature (such as 3D printing, sintering, and brazing), making it easy to mass-produce and with broad application prospects. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a 3D vapor chamber for heat dissipation of small-area chips according to an embodiment of the present invention.

[0018] Figure 2 This is an exploded view of a 3D vapor chamber for heat dissipation of small-area chips according to an embodiment of this utility model.

[0019] Figure 3 yes Figure 2 Enlarged view of point A in the middle.

[0020] Figure 4 yes Figure 2 Enlarged view of point B in the middle.

[0021] Figure 5 yes Figure 2 Enlarged view of point C in the middle.

[0022] Figure 6 yes Figure 2 Enlarged view of point D in the middle.

[0023] Figure 7 This is a three-dimensional structural diagram of the 3D vapor chamber for heat dissipation of small-area chips according to another embodiment of the present invention.

[0024] Explanation of icon numbers 1. Top cover plate, 2. Bottom cover plate, 3. Copper tube, 4. Copper column, 5. Micro needle, 6. Bottom cover capillary, 7. Top cover capillary, 8. Copper column capillary, 9. Micro needle capillary, 10. Micro groove, 11. Bridge capillary, 12. Copper tube groove, 13. Support column. Detailed Implementation

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0028] Please refer to Figures 1 to 7 The 3D vapor chamber for heat dissipation of small-area chips according to this embodiment of the invention includes an upper cover plate, a lower cover plate, and a copper tube. The upper cover plate and the lower cover plate are sealed together to form a closed cavity. The closed cavity is divided into a non-heat source area and a heat source area corresponding to the small-area chip. The closed cavity is filled with a working fluid. The heat source area corresponding to the lower cover plate is a groove. The lower end of the copper tube is open, and the inside of the copper tube communicates with the closed cavity. The inner wall of the copper tube is provided with copper tube capillaries. This part is a conventional structure and will not be described in detail here. The non-heat source area inside the closed cavity is distributed with three-dimensional porous liquid storage chambers.

[0029] The heat source area contains several uniformly distributed copper pillars arranged in an array. The lower cover plate of the heat source area has several microneedles, and the surface of the lower cover plate inside the sealed cavity has lower cover capillaries. The lower surface of the upper cover plate inside the sealed cavity has upper cover capillaries, and copper pillar capillaries are located around the outer periphery of the copper pillars. Corresponding microneedle capillaries are located on the surface of the microneedles (i.e., their outer periphery and top surface). The upper and lower ends of the copper pillar capillaries overlap with the upper and lower cover capillaries, respectively, and the microneedle capillaries overlap with the lower cover capillaries. The overlaps between the capillaries form interconnected multi-stage flow distribution channels. Multi-stage flow distribution channels: Copper column capillaries are positioned near the condensation zone of the upper capillary, connecting to it. These copper column capillaries are tentatively designated as the first-stage sub-channel. A three-dimensional bridge connects each copper column capillary, forming a second-stage sub-channel. Copper tubes are grafted onto the bridge capillaries to form a third-stage sub-channel, and so on. The final sub-channel connects to the three-dimensional porous liquid storage chamber. Through this multi-stage flow distribution of "main channel - sub-channel," the condensed working fluid is dispersed to multiple return paths, increasing the total cross-sectional area of ​​the return channels by 2-3 times compared to traditional single channels. A confluence channel is formed near the composite capillary core of the lower capillary, drawing the working fluid from the final sub-channel to the main liquid supply channel (the area between the confluence channel and the composite capillary core forms the main liquid supply channel). This main liquid supply channel connects to the composite capillary core, ensuring a concentrated supply of working fluid to the heat source area. A return area multiplication channel is located inside the upper cover plate, connecting to the composite capillary core and the three-dimensional porous liquid storage chamber.

[0030] A number of microneedles are evenly distributed to form a microneedle array. The microneedles are made of oxygen-free copper and come into direct contact with the heat source of the small-area chip. The microneedle array can reduce the contact area while shortening the heat conduction path and reducing the contact thermal resistance. The diameter of the microneedles ranges from 0.1 mm to 0.5 mm, and the height ranges from 0.1 mm to 1.0 mm.

[0031] The small-area chip heat source has a small area and a heat flux density ≥500W / cm².

[0032] In one implementation, the lower cover plate of the heat source area is provided with multiple sets of microgrooves, and the micro-pins are correspondingly located in the area between the microgrooves of the lower cover plate. The microgrooves form capillary liquid storage chambers, which are capillarily connected to the lower cover, enabling rapid supply of the working fluid and efficient escape of steam.

[0033] In one implementation, copper pipes are provided on the upper cover plate corresponding to the heat source area and the non-heat source area. A bridge capillary is provided below the copper pipe in the heat source area. The bridge capillary is located between two copper pillars, and its two ends are respectively connected to the copper pillar capillary on the two copper pillars. The bridge capillary is connected to the copper pipe capillary inside the copper pipe above.

[0034] In one implementation, the bridge capillary is provided with copper tube grooves for fixing copper tubes. The copper tubes on the bridge capillary are inserted into these copper tube grooves during installation.

[0035] In one implementation, the surfaces of the lower cover capillary, upper cover capillary, copper column capillary, microneedle capillary, and / or bridge capillary within the sealed cavity are provided with micro-nano groove structures, i.e., micro-nano groove structures are set on the inner walls of the multi-stage diversion channels and confluence channels. The micro-nano groove structure consists of several micro-nano grooves. Preferably, the depth of the micro-nano grooves ranges from 5μm to 10μm, and the spacing between the micro-nano grooves ranges from 10μm to 15μm. The micro-nano groove structure is fabricated through an electrochemical etching process or an integral forging process. The micro-nano groove structure can increase the heat transfer area of ​​the channel wall and enhance the turbulence effect of the working fluid, thereby increasing the heat transfer coefficient by 30%-50%.

[0036] As one implementation method, microneedles, microneedle capillaries, microgrooves, and lower capillary capillaries in the heat source area (the lower capillary capillaries in the heat source area can be referred to...) Figure 4 The composite capillary core is composed of a total area of ​​(1.2-1.5):1, which ensures full coverage of the heat source area and no excess thermal resistance loss.

[0037] Through the above structure, the reflux area of ​​the 3D steam chamber of this invention is doubled, and the maximum heat transfer capacity (Qmax) is increased by 50%-80% compared with the traditional structure.

[0038] When the 3D vapor chamber of this invention is in operation, the heat generated by the small-area chip heat source is rapidly transferred to the lower capillary through the microneedle array of the composite capillary core. The working fluid absorbs heat and evaporates into steam within the lower capillary core. The steam diffuses into the condensation area of ​​the upper cover plate within the sealed cavity, releases heat, and condenses into liquid. The condensed liquid is dispersed and flows through the multi-stage diversion channel of the return flow area multiplication channel, and the return flow is accelerated under the action of the micro-nano groove structure. Finally, it is transported to the three-dimensional porous liquid storage chamber for storage through the confluence channel. When the working fluid in the composite capillary core area is insufficient, the working fluid in the three-dimensional porous liquid storage chamber is replenished to the composite capillary core through the microchannel, completing the working fluid circulation and achieving continuous and efficient heat dissipation.

[0039] As one implementation method, several support columns are provided on the lower cover plate of the non-heat source area.

[0040] This invention is particularly suitable for heat dissipation scenarios of microelectronic devices that require low thermal resistance, high liquid volume, and high heat transfer capacity.

[0041] The 3D vapor chamber for heat dissipation of small-area chips of this invention can be prepared by the following method, which includes: ~ Step 1: Prepare the upper cover plate, copper tube, and lower cover plate with microneedles and copper pillars. The lower cover plate with microneedles, copper pillars, and support pillars can be integrally forged. The microneedles and microgrooves on the lower cover plate are integrally stamped or formed by electrochemical etching of the microgrooves.

[0042] Step 2: Weld the top cover plate and copper tube, and prepare the top cover capillary and copper tube capillary respectively on the top cover plate and copper tube. Prepare a nano-coating or sintered copper powder layer (i.e., bottom cover capillary, microneedle capillary) on the bottom cover plate to form a composite capillary core; prepare copper column capillary and bridge capillary on the bottom cover plate, and overlap to form a three-dimensional porous liquid storage cavity.

[0043] Step 3: Fabricate a micro-nano groove structure, seal the top and bottom cover plates, inject working fluid and evacuate to obtain a 3D vapor chamber for heat dissipation of small-area chips.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A 3D vapor chamber for heat dissipation of small-area chips, comprising an upper cover plate and a lower cover plate, the upper cover plate and the lower cover plate being sealed together to form a sealed cavity; the sealed cavity is divided into a non-heat source area and a heat source area corresponding to the small-area chip, characterized in that, The heat source area is provided with several copper pillars, the lower cover plate of the heat source area is provided with several micro needles, the surface of the lower cover plate in the sealed cavity is provided with lower cover capillary, the lower surface of the upper cover plate in the sealed cavity is provided with upper cover capillary, the outer periphery of the copper pillars is provided with copper pillar capillary, the surface of the micro needles is provided with micro needle capillary, the upper and lower ends of the copper pillar capillary overlap with the upper cover capillary and the lower cover capillary respectively, and the micro needle capillary overlaps with the lower cover capillary.

2. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 1, characterized in that, The surface of the lower cover plate of the heat source area is provided with multiple sets of micro grooves, and the micro needles are correspondingly located in the area between the micro grooves of the lower cover plate, and the micro needles form a micro needle array.

3. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 1, characterized in that, The upper cover plate is equipped with copper pipes corresponding to the heat source area, and copper pipe capillaries are installed inside the copper pipes. Bridge capillaries are installed below the copper pipes in the heat source area. The bridge capillaries are located between two copper pillars, and the two ends of the bridge capillaries overlap with the copper pillar capillaries on the two copper pillars respectively. The bridge capillaries overlap with the copper pipe capillaries inside the copper pipe above.

4. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 3, characterized in that, The bridge capillary is equipped with a copper tube groove for fixing copper tubes.

5. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 3, characterized in that, The surfaces of the lower cover capillary, upper cover capillary, copper column capillary, micro needle capillary and / or bridge capillary in the sealed cavity are provided with micro-nano groove structures, and the micro-nano groove structures are composed of several micro-nano grooves.

6. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 5, characterized in that, The depth of the micro-nano grooves ranges from 5μm to 10μm, and the spacing between the micro-nano grooves ranges from 10μm to 15μm.

7. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 5, characterized in that, The micro-nano groove structure is prepared by electrochemical corrosion or integral forging.

8. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 1, characterized in that, The diameter of the microneedles ranges from 0.1 mm to 0.5 mm, and the height ranges from 0.1 mm to 1.0 mm.

9. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 1, characterized in that, The composite capillary core consists of microneedles, microneedle capillaries, microgrooves, and the lower cover capillary of the heat source area. The ratio of the total area of ​​the composite capillary core to the heat source area of ​​the small-area chip is (1.2-1.5):

1.

10. The 3D vapor chamber for heat dissipation of small-area chips as described in claim 1, characterized in that, Several support columns are provided on the lower cover plate of the non-heat source area.

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