Chip self-adaptive heat dissipation device based on shape memory alloy and preparation method

Abstract

The invention discloses a shape memory alloy-based chip self-adaptive heat dissipation device and a preparation method, relates to the technical field of chip heat dissipation, and solves the problem that the heat dissipation effect of an existing heat dissipation device on local hot spots randomly appearing on a chip is poor. A substrate is arranged at the lower end of a shell to form a micro box body structure, and a honeycomb liquid separation plate is arranged in the micro box body structure; the honeycomb liquid separation plate is of a double-layer structure and is provided with a plurality of honeycomb liquid separation inlets penetrating up and down; a honeycomb liquid separation outlet formed in the lower surface of the honeycomb liquid separation plate is communicated with a cavity in the honeycomb liquid separation plate, and the cavity is communicated with a liquid outlet in the side face of the shell; a liquid inlet is formed in the upper end of the shell; a shape memory alloy layer and needle-shaped ribs are arranged on the substrate. According to the invention, martensite phase transformation of the shape memory alloy is triggered in a local high-temperature area of the chip, so that the surface of the radiator forms a bulge at a high-temperature part, thereby increasing the heat exchange area of contact between a flowing working medium and the radiator, providing more nucleation sites in two-phase cooling, and remarkably improving the heat exchange efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of chip heat dissipation, and in particular to a chip adaptive heat dissipation device based on shape memory alloy and a preparation method thereof. Background Art

[0002] With the development of micro-electromechanical systems, the integration of various devices has been continuously improved, the heat generation per unit volume has further increased, and the heat dissipation space has further decreased, which has brought severe challenges to the thermal management of the equipment. It is necessary to adopt efficient heat dissipation methods to ensure the safe and stable operation of the equipment. According to statistics, from 1980 to 1999, with the development of electronic component manufacturing technology and packaging technology, the heat dissipation per unit area of ​​the chip in MEMS has reached 200W / cm 2 At present, the heat dissipation of microelectronic components has reached 1000W / cm 2 . During the operation of MEMS, the rise in operating temperature will cause the failure rate of electronic components to increase exponentially. When electronic components operate between 70℃ and 80℃, the probability of device failure increases by 5% for every 1 degree increase in temperature. Due to the insufficient heat dissipation capacity of traditional heat dissipation materials / devices, MEMS can only exert 20% to 30% of its theoretical performance. In order to improve the performance of electronic devices and give full play to the performance potential of microelectronic devices, efficient heat dissipation is the key.

[0003] Most of the current chip cooling technologies improve the overall cooling efficiency by optimizing the structure of the heat sink, but the research on cooling solutions for dealing with local hot spots in the chip is relatively limited. The existing heat sink structure usually lacks adaptive control capabilities, resulting in uneven temperature distribution on the chip surface, which makes it difficult to meet the heat dissipation needs of the chip in the actual working environment. In a very few studies, although semiconductor integration technology is used to predict the location of chip hot spots, and a special flow channel structure is designed accordingly to improve the heat dissipation performance, the limitation of this method is that the cooling structure is fixed and can only cool the predetermined area. It is slow to respond to randomly appearing hot spots, the cooling effect is poor, and precise heat dissipation control cannot be achieved. Therefore, in order to solve the problem of excessive temperature and possible thermal failure caused by the random generation of local hot spots in the chip under high heat flux conditions, it is urgent to develop a heat dissipation system that can achieve adaptive control to ensure the stability of the local temperature of the chip, thereby effectively avoiding the risk of thermal failure caused by local power imbalance. Summary of the invention

[0004] In order to solve the problem mentioned above that the existing heat sink has poor heat dissipation effect on the local hot spots that randomly appear on the chip, the present invention proposes a chip adaptive heat dissipation device based on shape memory alloy and a preparation method. The present invention induces the martensitic phase transformation of the shape memory alloy in the local high-temperature area of ​​the chip, so that the surface of the heat sink forms a bulge at the high-temperature part, thereby increasing the heat exchange area of ​​the flowing working fluid in contact with the heat sink, and at the same time provides more nucleation sites in two-phase cooling, significantly improving the heat exchange efficiency.

[0005] The present invention proposes a chip adaptive heat dissipation device based on shape memory alloy, which specifically includes an outer shell, a substrate and a honeycomb liquid separation plate. The lower end of the outer shell is provided with a substrate to form a box structure, and a honeycomb liquid separation plate is provided in the box structure; the honeycomb liquid separation plate is a double-layer structure, and is provided with a plurality of honeycomb liquid separation inlets running through the upper and lower parts; a plurality of honeycomb liquid separation outlets are provided on the lower surface of the honeycomb liquid separation plate, and the honeycomb liquid separation outlets are connected to the cavity in the honeycomb liquid separation plate; a shape memory alloy layer is provided on the substrate; a liquid inlet is provided at the upper end of the outer shell, and a plurality of liquid outlets are provided on the side, and the liquid outlets are connected to the internal cavity of the honeycomb liquid separation plate.

[0006] Furthermore, a plurality of needle-shaped ribs are arranged on the substrate, and the tips of the needle-shaped ribs pass through the shape memory alloy layer and face the honeycomb liquid separation inlet and the honeycomb liquid separation outlet.

[0007] Furthermore, the upper liquid separation layer formed between the honeycomb liquid separation plate and the top of the housing is connected through the honeycomb liquid separation inlet and the lower channel layer formed between the honeycomb liquid separation plate and the base.

[0008] Furthermore, the lower channel layer is connected to the middle fluid outflow layer in the middle of the honeycomb liquid separation plate through the honeycomb liquid separation outlet.

[0009] Furthermore, the liquid inlet is arranged at the center of the upper surface of the shell.

[0010] A method for preparing the above-mentioned chip adaptive heat dissipation device based on shape memory alloy, depositing the shape memory alloy on the surface of the substrate, and polishing the surface when the shape memory alloy is in the martensite phase; installing the honeycomb liquid separation structure inside the shell; and installing the substrate to the bottom of the shell.

[0011] Furthermore, the phase transition point temperature of the shape memory alloy is adjusted according to a preset temperature by adjusting the types and percentages of components of the alloy material.

[0012] The beneficial effects of the chip adaptive heat dissipation device based on shape memory alloy and the preparation method described in the present invention are:

[0013] (1) The present invention discloses a chip adaptive heat dissipation device based on shape memory alloy and its preparation method, which overcomes the problem that existing heat sinks have poor heat dissipation effect on the local hot spots that randomly appear on the chip, and realizes adaptive heat dissipation in the local high-temperature area of ​​the chip by utilizing the martensitic phase transformation and reverse phase transformation process of the shape memory alloy. When the local temperature of the chip rises to the critical point, the shape memory alloy undergoes a martensitic phase transformation, causing a bulge on the surface of the heat sink in the high-temperature area, thereby improving the heat exchange efficiency in single-phase cooling. At the same time, the bulge structure provides more nucleation points for liquid two-phase cooling, significantly enhancing the heat dissipation capacity of the local high-temperature area;

[0014] (2) The present invention discloses a chip adaptive heat dissipation device based on shape memory alloy and a preparation method, which evenly distributes the fluid through a honeycomb liquid separation plate and realizes a smooth transition of the liquid through needle-shaped ribs to prevent the lateral velocity from being reduced due to the direct impact of the liquid. During the two-phase flow cooling process, the needle-shaped ribs can shorten the stretching time of the bubbles, accelerate the detachment of the bubbles, and reduce the possibility of bubble deposition, thereby improving the convective heat transfer coefficient of the device and enhancing the heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0016] In the attached picture:

[0017] Figure 1 It is a three-dimensional structural schematic diagram of a chip adaptive heat dissipation device based on shape memory alloy according to the present invention;

[0018] Figure 2 It is an isometric view of a smoke absorption unit of a chip adaptive heat dissipation device based on shape memory alloy according to the present invention;

[0019] Wherein: 1-shell, 2-liquid inlet, 3-upper liquid separation layer, 4-middle fluid outflow layer, 5-lower channel layer, 6-base, 7-needle-shaped ribs, 8-shape memory alloy layer, 9-honeycomb liquid separation inlet, 10-honeycomb liquid separation outlet, 11-honeycomb liquid separation plate, 12-liquid outlet, 121-liquid outlet one, 122-liquid outlet two, 123-liquid outlet three, 124-liquid outlet four. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0023] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Specific implementation method 1: See Figure 1-Figure 2 The present embodiment is described in detail. The chip adaptive heat dissipation device based on shape memory alloy described in the present embodiment specifically includes a shell 1, a substrate 6 and a honeycomb liquid separation plate 11. The lower end of the shell 1 is provided with a substrate 6 to form a micro box structure, and a honeycomb liquid separation structure is provided in the micro box structure; the honeycomb liquid separation plate 11 is a double-layer structure, consisting of two layers of honeycomb structures, the honeycombs are regular octagons, and a cavity is provided in the middle of the two layers of honeycomb structures; a plurality of honeycomb liquid separation inlets 9 are provided between the two layers of honeycomb structures, and the honeycombs facing each other between the two layers of honeycomb structures are connected through the honeycomb liquid separation inlet 9, so that the upper liquid separation layer 3 formed between the honeycomb liquid separation plate 11 and the top of the shell 1 and the lower channel layer 5 formed between the honeycomb liquid separation plate 11 and the substrate 6 can be connected through the honeycomb liquid separation inlet 9; the remaining honeycombs on the honeycomb structure of the lower layer of the honeycomb liquid separation plate 11 constitute a honeycomb liquid separation outlet 10, and the lower channel layer 5 is connected to the middle fluid outflow layer 4 in the middle of the honeycomb liquid separation plate 11 through a plurality of honeycomb liquid separation outlets 10. The middle fluid outflow layer 4 and the honeycomb liquid separation inlet 9 are not connected.

[0025] A shape memory alloy layer 8 is provided on the substrate 6. When the temperature rises, the shape memory alloy layer 8 changes from the martensite phase to the austenite phase. Accompanying the phase change, a convex phenomenon appears on the surface of the material, which increases the heat exchange area and nucleation sites, thereby enhancing the heat dissipation effect of the local high-temperature area, reducing the temperature difference of the device, making the temperature distribution more uniform, and realizing adaptive control. Based on the memory effect of the shape memory alloy, when the temperature drops, the material returns to the martensite phase and the surface becomes smooth again.

[0026] The center of the upper surface of the housing 1 is provided with a liquid inlet 2, and the side is provided with a plurality of liquid outlets 12, which are connected to the middle fluid outflow layer 4 inside the honeycomb liquid separation plate 11. The liquid outlets 12 include a liquid outlet 121, a liquid outlet 2 122, a liquid outlet 3 123 and a liquid outlet 4 124, which are respectively provided on the four sides of the housing 1.

[0027] The base 6 is provided with a plurality of needle-shaped ribs 7, the tips of which pass through the shape memory alloy layer 8 and face the honeycomb liquid separation inlet 9 and the honeycomb liquid separation outlet 10, and their function is to make the fluid transition smoothly and prevent the lateral velocity from being reduced due to the direct impact of the liquid. In the two-phase flow cooling process, the needle-shaped ribs can shorten the stretching time of the bubbles, accelerate the detachment of the bubbles, and reduce the possibility of bubble deposition, thereby improving the convective heat transfer coefficient of the device and enhancing the heat dissipation performance.

[0028] A method for preparing the above-mentioned chip adaptive heat dissipation device based on shape memory alloy, depositing shape memory alloy on the surface of substrate 6 to form shape memory alloy layer 8, and polishing the surface of shape memory alloy layer 8 to make the surface smooth when the shape memory alloy is in martensite phase; installing the honeycomb liquid separation structure inside the shell 1; installing the substrate 6 to the bottom of the shell 1.

[0029] The phase transition point temperature of the shape memory alloy at which the martensite phase transforms to the austenite phase is adjusted according to the preset temperature by adjusting the types and percentages of the components of the alloy material to achieve adaptive adjustment within the required specific temperature range.

[0030] The specific working process of the chip adaptive heat dissipation device based on shape memory alloy described in the present invention is:

[0031] The fluid enters the upper liquid separation layer 3 inside the housing 1 through the liquid inlet 2, and enters the lower channel layer 5 through a number of honeycomb liquid separation inlets 9 set on the honeycomb liquid separation plate 11. By evenly diverting the fluid, the upper honeycomb structure realizes uniform liquid impact on the substrate 6 with needle-shaped ribs 7 and shape memory alloy 8 below; under the diversion effect of the needle-shaped ribs 7, the fluid smoothly transitions and contacts the shape memory alloy layer 8 for heat exchange; then, with the help of the transition effect of the needle-shaped ribs 7 again, the fluid smoothly enters the middle fluid outflow layer 4 from the honeycomb liquid separation outlet 10, and the liquid is quickly outflowed through the lower honeycomb structure, so that the overall heat dissipation of the device is more uniform, the temperature difference is reduced, and the heat dissipation performance is improved; finally, the fluid flows out through the liquid outlet 12. When the temperature rises, the shape memory alloy layer 8 transforms from the martensite phase to the austenite phase, and a convex phenomenon appears on the surface, which increases the heat exchange area with the fluid. These settings ensure adaptive heat dissipation in local high-temperature areas of the chip, greatly improve the temperature uniformity and heat dissipation capacity of the device, ensure stable operation of the chip under high heat flux density, and effectively prevent thermal failure problems caused by local excessive temperature.

[0032] The present invention is based on the martensitic phase transformation and reverse phase transformation process of shape memory alloy, which produces surface protrusions in the local high-temperature area of ​​the chip, realizes adaptive heat dissipation adjustment of the chip, significantly improves the heat dissipation efficiency of the heat dissipation device and the temperature uniformity of the chip, and greatly enhances the overall heat dissipation performance of the equipment, effectively avoiding the problem of thermal failure of the chip due to local high temperature caused by local heat flow in the chip.

[0033] Summarizing the above implementation cases, the chip adaptive heat dissipation device and preparation method based on shape memory alloy described in the present invention overcome the problem that the existing heat sink has poor heat dissipation effect on the local hot spots that randomly appear on the chip, and realizes adaptive heat dissipation in the local high-temperature area of ​​the chip by utilizing the martensitic phase transformation and reverse phase transformation process of the shape memory alloy. When the local temperature of the chip rises to the critical point, the shape memory alloy undergoes a martensitic phase transformation, causing the surface of the heat sink to produce a bulge in the high-temperature area, thereby improving the heat exchange efficiency in single-phase cooling. At the same time, the bulge structure provides more nucleation points for liquid two-phase cooling, significantly enhancing the heat dissipation capacity of the local high-temperature area; the chip adaptive heat dissipation device and preparation method based on shape memory alloy described in the present invention, through the honeycomb liquid separation plate 11 set to make the fluid evenly diverted, and through the needle-shaped ribs 7 to achieve smooth transition of the liquid, to prevent the lateral velocity from being reduced due to the direct impact of the liquid; in the two-phase flow cooling process, the needle-shaped ribs can shorten the stretching time of the bubbles, accelerate the detachment of the bubbles, and reduce the possibility of bubble deposition, thereby improving the convective heat transfer coefficient of the device and enhancing the heat dissipation performance.

[0034] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the invention. It can also be a reasonable combination of the features recorded in the above implementation methods. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A chip adaptive heat dissipation device based on shape memory alloy, characterized in that: The invention comprises an outer shell (1), a base (6) and a honeycomb liquid separation plate (11); the base (6) is arranged at the lower end of the outer shell (1) to form a box structure, and the honeycomb liquid separation plate (11) is arranged in the box structure; the honeycomb liquid separation plate (11) is a double-layer structure and is provided with a plurality of honeycomb liquid separation inlets (9) running through the upper and lower parts; a plurality of honeycomb liquid separation outlets (10) are arranged on the lower surface of the honeycomb liquid separation plate (11), and the honeycomb liquid separation outlets (10) are in communication with the cavity in the honeycomb liquid separation plate (11); A shape memory alloy layer (8) is provided on the substrate (6); The upper end of the housing (1) is provided with a liquid inlet (2), and the side surface is provided with a plurality of liquid outlets (12), and the liquid outlets (12) are in communication with the internal cavity of the honeycomb liquid separation plate (11).

2. The chip adaptive heat dissipation device based on shape memory alloy according to claim 1, characterized in that: A plurality of needle-shaped ribs (7) are arranged on the substrate (6), and the tips of the needle-shaped ribs (7) pass through the shape memory alloy layer (8) and face the honeycomb liquid separation inlet (9) and the honeycomb liquid separation outlet (10).

3. The chip adaptive heat dissipation device based on shape memory alloy according to claim 2, characterized in that: The upper liquid separation layer (3) formed between the honeycomb liquid separation plate (11) and the top of the housing (1) is connected through the honeycomb liquid separation inlet (9) and the lower channel layer (5) formed between the honeycomb liquid separation plate (11) and the base (6).

4. The chip adaptive heat dissipation device based on shape memory alloy according to claim 3, characterized in that: The lower channel layer (5) is connected to the middle fluid outflow layer (4) in the middle of the honeycomb liquid separation plate (11) through the honeycomb liquid separation outlet (10).

5. The chip adaptive heat dissipation device based on shape memory alloy according to claim 1, characterized in that: The liquid inlet (2) is arranged at the center of the upper surface of the housing (1).

6. A method for preparing the chip adaptive heat dissipation device based on shape memory alloy according to claim 1, characterized in that: Depositing a shape memory alloy on a surface of a substrate (6), and polishing the surface when the shape memory alloy is in a martensite phase; Installing the honeycomb liquid separation structure inside the housing (1); Install the base (6) to the bottom of the housing (1).

7. The method of the chip adaptive heat dissipation device based on shape memory alloy according to claim 6, characterized in that: The phase transition point temperature of the shape memory alloy is adjusted according to a preset temperature by adjusting the types and percentages of the components of the alloy material.

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