A small electronic component chip package

Abstract

The application discloses a small electronic component chip package and relates to the technical field of chip package.The application comprises a base body, wherein the base body is a fully-sealed hollow laminated structure and sequentially comprises a cover plate, a hierarchical micro-nano heat exchange element, a cavity frame, a partition plate and a condensation reflux bottom plate from top to bottom; a middle portion of the top of the cavity frame is provided with an evaporation concave cavity, the hierarchical micro-nano heat exchange element is arranged in the evaporation concave cavity, and a ring-shaped liquid supply micro groove is formed in the bottom of the cavity frame and is annularly distributed outside the evaporation concave cavity; and the hierarchical micro-nano heat exchange element makes the ring-shaped liquid supply micro groove flow out through capillary action.The application adopts coaxial ring-shaped flow channel and layered cavity design, liquid phase converges and evaporates from the periphery to the center, and gas phase diffuses from the center to the periphery and then flows downward to the lower layer for condensation, so that the problems of gas-liquid shearing and reflux blockage of a traditional heat plate are completely avoided, and the critical dry-out heat flux density is effectively improved compared with a conventional heat base island of the same size.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, and more specifically to a chip packaging for small electronic components. Background Technology

[0002] The chip carrier island is a core structural component of semiconductor packaging. On the one hand, it bears the mechanical load and positioning function of the chip; on the other hand, it serves as the core hub for heat conduction from the chip. Its thermal conductivity and heat dissipation capabilities directly determine the overall heat dissipation performance of the package. As the power density of small electronic component chips continues to increase, the traditional solid copper-based island heat dissipation method, which relies on solid-state heat conduction, has reached its performance bottleneck. The problems of large temperature differences and high thermal resistance on the chip surface are becoming increasingly prominent, which can easily lead to local overheating, performance degradation, or even failure of the chip.

[0003] A Chinese patent (publication number: CN114927489B) discloses a cooling system for an embedded microfluidic thin-film phase change chip, comprising an electronic chip module, a condenser, a liquid storage tank, and a working fluid pump. The inlet end of the electronic chip module is connected to the working fluid pump, the outlet end of the electronic chip module is connected to the inlet end of the condenser, the outlet end of the condenser is connected to the inlet end of the liquid storage tank, and the outlet end of the liquid storage tank is connected to the working fluid pump. The electronic chip module includes a microfluidic manifold structure and a semiconductor bare chip. A micro-nano structure is provided on one side surface of the semiconductor bare chip, and the microfluidic manifold structure is provided with microchannels and a vapor chamber.

[0004] The above solution is essentially an open system-level cooling solution with external power, requiring a separate working fluid pump, liquid storage tank, condenser, and external connection pipelines. The overall size is huge, making it impossible to integrate into millimeter-scale surface mount packages, let alone use it as an independent chip carrier island to directly replace traditional solid substrate islands in standard packaging processes. At the same time, the system contains moving parts and pipeline interfaces, which pose risks of pump wear and working fluid leakage. Its reliability is difficult to meet the passive, high-reliability, and maintenance-free requirements of micro-packaging scenarios such as consumer electronics and wearable devices.

[0005] In existing technologies, passive phase change substrates suffer from drawbacks such as gas-liquid backflow interference, low critical heat flux density, and insufficient condensation area, making it difficult to continuously improve heat dissipation performance. While active pump-driven phase change cooling solutions offer excellent performance, they are bulky and cannot achieve passive integration at the package level. Neither approach can simultaneously meet the heat dissipation requirements of miniaturization, complete passivity, high heat flux, and high integration for small packages. Therefore, developing a chip carrier substrate that can be fully embedded in a standard package, requires no external power, and combines high heat transfer performance with multifunctional integration is a pressing technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a small electronic component chip package to solve the above problems.

[0007] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0008] A small electronic component chip package includes a substrate, which is a fully sealed hollow stacked structure, and from top to bottom includes a cover plate, a hierarchical micro-nano heat exchanger, a cavity frame, a partition and a condensation reflux bottom plate.

[0009] An evaporation cavity is provided in the middle of the top of the cavity frame. The hierarchical micro-nano heat exchanger is placed in the evaporation cavity. An annular liquid supply micro-groove is opened at the bottom of the cavity frame. The annular liquid supply micro-groove is distributed in a ring on the outside of the evaporation cavity. The hierarchical micro-nano heat exchanger causes the liquid to flow out of the annular liquid supply micro-groove through capillary action. A steam collection area is provided between the cavity frame and the substrate. A steam diffusion area is provided between the cavity frame and the cover plate. The steam diffusion area and the steam collection area are connected.

[0010] A steam condensation zone is provided between the partition plate and the condensation return bottom plate. A steam guide hole is provided on the partition plate to connect the steam condensation zone and the steam collection zone. A return element is provided at the bottom of the partition plate, which causes the condensate to flow back to the annular liquid supply micro-trough through capillary action.

[0011] Furthermore, the cover plate has an ultra-thin substrate window in the middle, and a thickened support frame is retained around the window.

[0012] Furthermore, the hierarchical micro / nano heat exchanger includes a bottom evaporation capillary groove and a top nanoporous copper layer. A drain capillary hole is opened on the outer side of the annular liquid supply micro-groove, and the evaporation capillary groove and the drain capillary hole are connected.

[0013] Furthermore, the evaporation capillary grooves are arranged radially.

[0014] Furthermore, a liquid-guiding sinking part is provided in the middle of the partition, the cavity frame is inserted into the liquid-guiding sinking part, and a liquid-guiding cavity is provided between the cavity frame and the bottom of the liquid-guiding sinking part. The return component is located at the center below the liquid-guiding sinking part.

[0015] Furthermore, the surface of the condensation reflux base plate is provided with a condensation capillary groove, and the middle of the condensation reflux base plate is provided with a liquid collection groove. The condensation capillary groove uses capillary action to guide the condensate into the liquid collection groove, and the reflux component is inserted into the liquid collection groove.

[0016] Furthermore, the reflux component has reflux capillary holes inside, the diameter of which is smaller than the width of the condensation capillary groove, to provide upward suction power.

[0017] Furthermore, the width of the condensation capillary groove is gradually varied, with a smaller width near the liquid collection groove.

[0018] Furthermore, the side edge of the condensation reflux base plate is integrally extended with at least two condensation arms, which are symmetrically distributed along the base to conduct condensation heat outward and provide a grounding path.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. This invention adopts a coaxial annular flow channel and layered cavity design. The liquid phase converges and evaporates from the periphery to the center, while the gas phase diffuses from the center to the surroundings and descends to the lower layer for condensation. The gas and liquid flow paths do not intersect or overlap, which completely avoids the gas-liquid shear and backflow blockage problems of traditional heat spreaders. The critical dry heat flux density is effectively improved compared with conventional heat spreaders of the same size.

[0021] 2. This invention provides low-resistance, high-flow-rate liquid phase transport through the bottom micron capillary groove of the hierarchical micro-nano heat exchanger, and the top nanoporous copper provides ultra-high capillary pressure head and forms an ultra-thin liquid film evaporation with a thickness of <10μm. This solves the problem that capillary force and flow resistance cannot be simultaneously achieved in a single capillary structure, improves the heat transfer coefficient, and ensures sufficient safety margin for liquid return.

[0022] 3. This invention requires no external power components. It relies on the self-generated pressure difference of steam to drive the gas phase flow and the staged capillary force to drive the liquid phase reflux. There are no moving parts or consumables, and the theoretical lifespan is consistent with that of the package body. The overall flat and miniaturized design can directly replace the traditional solid substrate island for standard surface mount packaging without the need for additional external systems.

[0023] 4. This invention achieves self-balancing and self-adjustment of the circulation by automatically matching the mutual constraint and capillary force of steam pressure difference, resulting in stable system operation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is an exploded view of the overall structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the hierarchical micro / nano heat exchanger structure of the present invention;

[0027] Figure 4 This is a schematic diagram of the cavity frame structure of the present invention;

[0028] Figure 5 This is a schematic diagram of the partition structure of the present invention.

[0029] Reference numerals: 1. Substrate; 2. Cover plate; 3. Staged micro / nano heat exchanger; 31. Evaporation capillary; 4. Cavity frame; 41. Evaporation cavity; 42. Annular liquid supply microchannel; 43. Drainage capillary; 5. Partition; 51. Liquid guiding sink; 52. Steam guide hole; 53. Reflux component; 54. Reflux capillary; 6. Condensation reflux base plate; 61. Condensation capillary; 62. Liquid collection groove; 7. Condensation support arm. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] Example 1, as Figures 1-5 As shown, a small electronic component chip package includes a substrate 1, which is a fully sealed hollow stacked structure, and from top to bottom includes a cover plate 2, a hierarchical micro-nano heat exchanger 3, a cavity frame 4, a partition 5 and a condensation reflux bottom plate 6.

[0032] An evaporation cavity 41 is provided in the middle of the top of the cavity frame 4. The graded micro-nano heat exchanger 3 is disposed in the evaporation cavity 41. An annular liquid supply micro-groove 42 is provided at the bottom of the cavity frame 4. The annular liquid supply micro-groove 42 is distributed in a ring on the outside of the evaporation cavity 41. The graded micro-nano heat exchanger 3 causes the annular liquid supply micro-groove 42 to flow out through the capillary action. A steam collection area is provided between the cavity frame 4 and the substrate 1. A steam diffusion area is provided between the cavity frame 4 and the cover plate 2. The steam diffusion area is connected to the steam collection area.

[0033] A steam condensation zone is provided between the partition plate 5 and the condensation return bottom plate 6. A steam guide hole 52 is provided on the partition plate 5. The steam guide hole 52 is used to connect the steam condensation zone and the steam collection zone. A return element 53 is provided at the bottom of the partition plate 5. The return element 53 causes the condensate to flow back to the annular liquid supply micro-trough 42 through capillary action.

[0034] The base island is made of oxygen-free copper TU1 material, and the phase change working fluid is deionized water or acetone, which is filled into the annular liquid supply micro-channel 42.

[0035] Working principle: The heat generated by the chip operation is conducted to the hierarchical micro-nano heat exchanger 3 through the cover plate 2. Under the capillary force of the hierarchical micro-nano heat exchanger 3, the liquid working fluid is transported from the annular liquid supply micro-channel 42 to the evaporation cavity 41 through the micron capillary channel. Under the action of heat, it is converted into steam. The steam pressure in the evaporation cavity 41 increases. The steam diffuses to the surrounding area through the steam diffusion zone and enters the steam collection zone. It enters the lower steam condensation zone through the steam guide hole 52. The steam condensation zone has a large area and diffuses.

[0036] Steam diffuses to the surroundings and bottom within the steam condensation zone. Upon contact with the condensation reflux bottom plate 6, it liquefies and releases heat. The reflux component 53 uses capillary action to return the condensate to the annular liquid supply micro-channel 42, completing the liquid phase reflux. The entire cycle is driven entirely by the combined action of steam pressure difference and staged capillary force. The gas and liquid paths are completely separated, with no cross-interference, enabling stable passive phase change homogenization.

[0037] Comparative analysis: In traditional vapor chambers, gas and liquid flow in opposite directions within the same cavity. When the steam flows upward, it carries the liquid working fluid, which hinders the liquid reflux. Under high heat flux density, local drying and a sudden increase in thermal resistance are very likely to occur.

[0038] This design employs a coaxial annular liquid supply system and a layered cavity structure: liquid flows from the outer annular liquid supply microchannel 42 through radial microchannels towards the center, while steam diffuses from the center outwards into the steam collection chamber, then descends to the lower steam condensation zone. The gas-liquid flow paths are completely physically separated, with no intersections or backflows, thus eliminating the problems of gas-liquid carryover and backflow blockage at the source.

[0039] Effect: The critical dry heat flux (CHF) is improved compared to conventional heat spreaders of the same size, and it has a very high safety margin under rated operating heat flux without circulation interruption.

[0040] This invention uses chip heating to vaporize the working fluid in the evaporation cavity 41, increasing the local steam pressure; in the steam condensation zone, the steam liquefies, reducing the pressure. A stable radial pressure difference spontaneously forms between the evaporation and condensation ends, continuously driving steam to flow from the central evaporation cavity 41 to the surrounding condensation zones. The higher the heat load, the greater the evaporation rate, the greater the pressure difference, and the faster the steam flow rate, exhibiting self-matching and self-accelerating adaptive characteristics, without experiencing insufficient power or overload.

[0041] The condensed liquid working fluid flows back from the condensation zone to the evaporation cavity 41 by the capillary suction pressure generated by the micro-nano capillary structure, continuously replenishing the liquid consumed by evaporation.

[0042] Vapor pressure difference and capillary force are mutually constrained and automatically matched: (1) The chip power consumption suddenly increases and the evaporation rate accelerates instantly. The amount of liquid consumed by evaporation in a short time exceeds the maximum amount of return liquid that the capillary structure can transport.

[0043] Automatic adjustment process: The liquid film at the edge of the evaporation cavity 41 is rapidly evaporated, resulting in locally dried areas. Without liquid coverage, the dried metal surface cannot continue phase change evaporation, effectively reducing the effective evaporation area and forcing a decrease in total evaporation. With the decrease in evaporation, less steam is generated per unit time, leading to a reduction in steam pressure at the evaporation end and a natural reduction in the steam pressure difference between the evaporation cavity 41 and the condensation zone. This reduced steam pressure difference means a slower steam flow rate, significantly weakening the reverse shearing and resistance effect of the steam on the returning liquid film. The effective driving force of capillary action increases, allowing more liquid to be drawn back into the evaporation cavity 41. The dried area is then re-covered by the liquid film, the evaporation rate recovers to a level matching the liquid return capacity, and the system enters a new stable state.

[0044] (2) The chip power consumption is reduced, the evaporation rate is slower, the amount of liquid returned is temporarily greater than the amount of liquid consumed by evaporation, the liquid film in the evaporation cavity 41 is too thick, or too much liquid working fluid is accumulated at the condensation end.

[0045] Automatic adjustment process: When the liquid supply is sufficient, the evaporation zone is 100% covered by the liquid film, and the effective evaporation area is at its maximum. As long as the chip continues to heat up, the liquid film will continue to absorb heat and evaporate, and the evaporation rate will naturally increase with the heat load. After the evaporation rate increases, the amount of steam generated per unit time increases, the steam pressure at the evaporation end increases, and the steam pressure difference between the evaporation zone and the condensation zone increases, pushing the steam to the condensation end more quickly. More steam quickly reaches the condensation end and liquefies, and the amount of condensate increases simultaneously; the capillary structure has a sufficient liquid source, and the return liquid rate increases accordingly, just matching the increased evaporation rate. The evaporation rate and the return liquid rate reach mass conservation again, and the system enters a new steady state under the corresponding heat load.

[0046] Example 2, based on the above examples, further includes an ultra-thin substrate window in the center of the cover plate 2, with a thickened support frame around the window. The ultra-thin substrate window is the area where the chip is directly bonded, maximizing the reduction of thermal resistance; the thickened support frame around the window ensures the strength of the cavity structure.

[0047] Example 3, based on the above examples, further includes a hierarchical micro / nano heat exchanger 3 comprising a bottom evaporation capillary trough 31 and a top nanoporous copper layer. A drain capillary pore 43 is provided on the outer side of the annular liquid supply micro-trough 42, and the evaporation capillary trough 31 is connected to the drain capillary pore 43. The evaporation capillary trough 31 is arranged radially.

[0048] Traditional single capillary structures present a dilemma: the finer the pores, the stronger the capillary force, but the greater the resistance to liquid flow and the insufficient total return flow; the coarser the pores, the smaller the flow resistance, but the insufficient capillary force cannot overcome gravity and flow resistance, and it is easy to dry out.

[0049] This scheme adopts a hierarchical structure of micron-channel transport and nanoporous copper evaporation: the bottom wide and deep evaporation capillary channel 31 is responsible for long-distance liquid transport, with low flow resistance and large throughput, ensuring the liquid supply; the top nanoporous copper layer provides ultra-high capillary suction pressure, spreading the liquid into an ultra-thin liquid film of <10μm, which not only enhances heat transfer, but also ensures that the evaporation cavity 41 is always covered by liquid.

[0050] Effect: It achieves both high capillary pressure head and low reflux resistance, greatly improving the capillary limit. Even when the chip experiences instantaneous peak power consumption, it can ensure a continuous liquid supply and prevent local dry burning.

[0051] Example 4, based on the above examples, further includes a liquid guiding sinking part 51 provided in the middle of the partition 5, a cavity frame 4 inserted into the liquid guiding sinking part 51, and a liquid guiding cavity provided between the cavity frame 4 and the bottom of the liquid guiding sinking part 51, and a return flow member 53 provided at the center below the liquid guiding sinking part 51.

[0052] The surface of the condensation reflux base plate 6 is provided with a condensation capillary groove 61, and the middle of the condensation reflux base plate 6 is provided with a liquid collection groove 62. The condensation capillary groove 61 uses capillary action to guide the condensate into the liquid collection groove 62, and the reflux component 53 is inserted into the liquid collection groove 62.

[0053] The reflux component 53 has a reflux capillary hole 54 inside. The diameter of the reflux capillary hole 54 is smaller than the width of the condensation capillary groove 61, which is used to provide upward suction power.

[0054] The width of the condensation capillary groove 61 is gradually set, with a smaller width near the liquid collection groove 62. The capillary force continuously increases along the flow direction, forming a natural unidirectional suction gradient. The liquid will only flow spontaneously along the gradient direction, and there will be no backflow or flow interruption.

[0055] By setting the liquid guide sink 51, the liquid storage volume of the annular liquid supply micro-channel 42 can be increased, and at the same time, the return component 53 can be vertically set in the central liquid collection groove 62.

[0056] Steam diffuses to the surroundings and bottom within the steam condensation zone, liquefying and releasing heat on the condensation return plate 6. The condensate flows back to the central collection groove 62 via the condensation capillary groove 61 on the bottom plate. Since the diameter of the return capillary hole 54 is smaller than the width of the condensation capillary groove 61, the return capillary hole 54 can generate stronger capillary suction, causing the condensate to return to the upper annular liquid supply micro-groove 42, completing the self-driven circulation.

[0057] Example 5, based on the above examples, further includes at least two condensing arms 7 integrally extending from the side edge of the condensing reflux base plate 6. The condensing arms 7 are symmetrically distributed along the base 1 and are used to conduct condensing heat outward and provide a grounding path.

[0058] The condenser support arm 7 and the condenser reflux base plate 6 are made of the same material and are integrated into one structure. They are completely located on the lower plane of the package, which does not damage the sealing of the upper evaporation chamber and the middle vapor chamber, nor does it occupy the upper space for chip mounting and bonding.

[0059] Core function: Extend the condensation end of the phase change cavity from the inside of the base island to the entire grounding pin, and then connect it to the large-area grounding heat dissipation plane of the PCB through SMT solder joints, which is equivalent to expanding the effective condensation area by 2-3 times, while providing a low-impedance grounding path for the conformal shielding layer and the phase change base island.

[0060] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A small electronic component chip package, comprising a substrate (1), characterized in that, The substrate (1) is a fully sealed hollow composite structure, which includes, from top to bottom, a cover plate (2), a graded micro-nano heat exchanger (3), a cavity frame (4), a partition plate (5), and a condensation reflux bottom plate (6). An evaporation cavity (41) is provided in the middle of the top of the cavity frame (4). A graded micro-nano heat exchanger (3) is provided in the evaporation cavity (41). An annular liquid supply micro-groove (42) is provided at the bottom of the cavity frame (4). The annular liquid supply micro-groove (42) is distributed in a ring on the outside of the evaporation cavity (41). The graded micro-nano heat exchanger (3) causes the annular liquid supply micro-groove (42) to flow out through capillary action. A steam collection area is provided between the cavity frame (4) and the substrate (1). A steam diffusion area is provided between the cavity frame (4) and the cover plate (2). The steam diffusion area is connected to the steam collection area. A steam condensation zone is provided between the partition (5) and the condensation return bottom plate (6). A steam guide hole (52) is provided on the partition (5). The steam guide hole (52) is used to connect the steam condensation zone and the steam collection zone. A return component (53) is provided at the bottom of the partition (5). The return component (53) causes the condensate to flow back to the annular liquid supply micro-trough (42) through capillary action.

2. The miniature electronic component chip package according to claim 1, characterized in that, The cover plate (2) has an ultra-thin substrate window in the middle, and a thickened support frame is retained around the window.

3. The small electronic component chip package according to claim 1, characterized in that, The graded micro-nano heat exchanger (3) includes a bottom evaporation capillary (31) and a top nanoporous copper layer. The outer side of the annular liquid supply micro-channel (42) is provided with a drain capillary (43), and the evaporation capillary (31) and the drain capillary (43) are connected.

4. A small electronic component chip package according to claim 3, characterized in that, The evaporation capillary grooves (31) are arranged radially.

5. A small electronic component chip package according to claim 1, characterized in that, The partition (5) has a liquid guiding sink (51) in the middle, the cavity frame (4) is inserted into the liquid guiding sink (51), and a liquid guiding cavity is provided between the cavity frame (4) and the bottom of the liquid guiding sink (51). The return component (53) is located at the center below the liquid guiding sink (51).

6. A small electronic component chip package according to claim 5, characterized in that, The surface of the condensation reflux base plate (6) is provided with a condensation capillary groove (61), and the middle of the condensation reflux base plate (6) is provided with a liquid collection groove (62). The condensation capillary groove (61) uses capillary action to guide the condensate into the liquid collection groove (62), and the reflux component (53) is inserted into the liquid collection groove (62).

7. A small electronic component chip package according to claim 6, characterized in that, The reflux component (53) has a reflux capillary hole (54) inside. The diameter of the reflux capillary hole (54) is smaller than the width of the condensation capillary groove (61) to provide upward suction power.

8. A small electronic component chip package according to claim 7, characterized in that, The width of the condensation capillary groove (61) is gradually set, with a smaller width near the liquid collection groove (62).

9. A small electronic component chip package according to claim 1, characterized in that, The side edge of the condensation return plate (6) is integrally extended with at least two condensation arms (7), which are symmetrically distributed along the base (1) to conduct condensation heat outward and provide a grounding path.

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