TWM623607U - Metal thermal conductive sheet structure with microparticles and phase change - Google Patents

Abstract

A metal heat-conducting thin sheet structure with particles and phase changes, comprising a heat-conducting matrix with a liquid metal alloy as the matrix; a nano-scale high heat-conducting powder, with particles with an average size of 10nm-10μm, dissolved in the heat-conducting matrix, and making the The thermally conductive substrate is phase-changed into a solid metal thermally conductive sheet with a thickness of 0.3cm~0.5cm; and the solid metal thermally conductive sheet is placed on the surface of a heat source, and the heated phase changes to liquid metal, extending into a metal with a thickness of less than 0.3cm Thermally conductive adhesive thin layer structure, with excellent adhesion and no solid-liquid separation. In this way, the defects caused by the conventional "liquid metal" thermal conductive material and "traditional thermal conductive paste" can be solved; with the structure of the solid metal thermal conductive sheet, through the phase change or metal oxidation process, it can be smoothly extended on the wafer to form a thin layer. Layered, the operation process is convenient and will not damage the chip, and the thin layer of thermally conductive adhesive can reduce thermal resistance, and has multiple functions such as good heat dissipation, safety and stability.

Description

Metal thermally conductive foil structure with particles and phase changes

This creation involves a metal thermally conductive sheet structure with particles and phase changes, especially a metal thermally conductive adhesive thin layer structure with excellent adhesion and no solid-liquid separation.

In recent years, semiconductor elements such as high-power central processing units (CPUs), graphics processing units (GPUs), and the like have developed rapidly. Electronic devices are becoming more and more thin and multi-tasking, and due to the increase in the density and frequency of electronic components, local overheating may occur after long-term use. Usually, the chip of electronic devices is the main heat source during operation, and heat dissipation is not only for the purpose of Reduce the temperature of the chip itself to ensure that it can work normally within the required temperature range. At the same time, it is necessary to take into account that the heat dissipation cannot cause local overheating of the casing, resulting in a poor user experience for consumers. At present, the heat dissipation method of electronic devices mainly uses simple However, these heat dissipation methods can no longer meet the heat energy generated by today's high-performance chips, so there will be problems of overheating, and the heat energy cannot be distributed evenly, resulting in a decrease in the heat dissipation efficiency inside the electronic device, which in turn leads to The phenomenon of system command frequency reduction or too slow crash also occurs from time to time.

"Liquid metal" is a low melting point alloy that is liquid at room temperature. Its main components are gallium indium tin alloy, indium bismuth tin alloy, or indium bismuth tin alloy, etc.; its properties are stable and have excellent thermal and electrical conductivity. , so many companies currently use "liquid metal" as a thermal conductive material to solve the above problems. However, the use of liquid metal as a heat dissipation material is not without lack; compared with traditional commercial thermal interface materials, gallium-based liquid metal has extremely low thermal resistance and good fluidity. At present, some researchers have developed an alloy with gallium, indium, bismuth and tin as the main components, and its total thermal resistance is at least 0.5K. mm ² /W. However, the surface tension of gallium and gallium alloys is relatively large (0.5-0.72N/m), the coating operation is difficult, and there is a disadvantage of poor wetting with the substrate; the good fluidity of liquid metal makes it easy to overflow from the interface, which makes the Risk of short circuit of electronic components.

At present, when the liquid metal reaches the phase change temperature, its fluidity is greatly improved, and it is easy to overflow and pollute electronic components. Therefore, a sealing structure needs to be designed for the surrounding area of the semiconductor coating, and a middle frame and a padding sealing material are added to prevent leakage and absorption. The tolerance of liquid metal consumption increases the difficulty and limitation of heat dissipation module design. Liquid metal is liquid at room temperature, which has certain restrictions on the coating process. Liquid metal can only be applied to the surface of semiconductor chips such as central processing units (CPUs) and graphics processing units (GPUs), but not on heat dissipation modules. flat and not flowing. Liquid metal and chip materials have poor wettability, and most of them are in the form of liquid beads during the construction process. The construction is more difficult than traditional thermal paste. It is necessary to strictly control the amount of liquid metal to prevent leakage.

On the contrary, the disadvantage of using traditional thermal paste is that it has poor fluidity or ductility. When it is applied to the surface of semiconductor wafers such as central processing units (CPUs) and graphics processing units (GPUs), or applied to the plane of the heat dissipation module, in the When operating the snap-fit process, a large force is required to squeeze the traditional thermal paste, which is easy to damage the semiconductor chip. Therefore, using traditional thermal paste, the thickness of the thermal paste cannot be reduced between the semiconductor chip and the heat dissipation module. , so that the thickness is more than 0.4cm, but the thermal resistance of too thick thermal paste is large, which affects its thermal conductivity and is missing.

Press again, after the liquid metal sheet on the market reaches the phase change temperature, it will form a fluid with better fluidity, which cannot efficiently fill the gap between the chip and the heat dissipation module, and even loses slowly for a long time. The interface material between the chips is short of material, and the temperature of the chips gradually rises, thereby triggering the overheating and frequency reduction protection of the chips.

Therefore, in view of the above problems, the author further proposes solutions for the deficiencies caused by liquid metal thermal conductive materials and traditional thermal conductive pastes.

The reason is that the main purpose of this creation is to provide a metal thermal conductive sheet structure with particles and phase changes, which has multiple functions such as good heat dissipation, safety and stability.

In order to achieve the above purpose, the technical means used in this creation include: a thermally conductive matrix, using a liquid metal alloy as the matrix; a nano-scale high thermal conductivity powder, with particles with an average size of 10nm~10μm, dissolved in the thermally conductive matrix, and make the thermally conductive substrate phase change into a solid metal thermally conductive sheet with a thickness of 0.3cm~0.5cm; and the solid metal thermally conductive sheet is placed on the surface of a heat source, and the heated phase changes into a liquid metal, extending into a thickness less than 0.3cm A thin layer of metal thermally conductive adhesive is constructed.

According to the above-mentioned feature, when the temperature of the heat source is greater than 58° C., the solid metal thermal conductive sheet undergoes a phase change.

According to the above-mentioned features, the nano-scale high thermal conductivity powder is of circular or quasi-circular particle structure.

According to the above-mentioned features, the nano-scale high thermal conductivity powder may include particles composed of metal powder or non-metal powder.

According to the above-mentioned feature, the heat source includes a semiconductor chip, and a heat sink is correspondingly provided on the semiconductor chip.

According to the above-mentioned feature, the contact surface of the heat sink and the metal thermally conductive adhesive thin layer structure further includes an anti-corrosion layer.

With the help of the above-mentioned technical means, this creation can solve the deficiencies caused by the conventional "liquid metal" thermal conductive material and "traditional thermal conductive paste"; with the structure of the solid metal thermal conductive sheet, after reaching the phase change temperature, it forms a solid or paste. , It is completely filled in the interface with gaps and becomes a good interface material, that is, it can be smoothly extended on the wafer to form a thin layer, and can be evenly combined on the surface of the heat source, and there is no solid-liquid separation phenomenon, and its operation process will not hurt. to wafer, and thin The layered thermally conductive adhesive can reduce thermal resistance, and has multiple functions such as good heat dissipation and safety and stability.

10: Thermally conductive substrate

20: Nano-scale high thermal conductivity powder

30: Solid metal thermal conductive sheet

30a: Thin-layer structure of metal thermally conductive adhesive

31: Oxidation

40: heat source (semiconductor wafer)

41: circuit board

42: Retaining Wall

50: Radiator

51: Anti-corrosion layer

Figure 1. The flow chart of the phase change of this creation.

Figure 2 is an exploded perspective view of a possible embodiment of the present creation.

Figure 3 is a three-dimensional schematic diagram of the phase change of the present creation.

Figure 4 is a schematic diagram of the structure of the thin layer of thermally conductive adhesive in this creation.

FIG. 5A is a cross-sectional view for reference in the use state of the present invention, showing the solid metal thermally conductive sheet 30 .

FIG. 5B is a cross-sectional view for reference in the use state of the present invention, showing a thin layer structure 30a of thermally conductive adhesive.

FIG. 6 is an enlarged view of the position circled by 6 in FIG. 5B .

The following describes the implementation of the present invention by means of specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

First, please refer to FIG. 1 to FIG. 6 , a feasible embodiment of the “metal thermally conductive sheet structure with particles and phase changes” of the present invention includes: a thermally conductive substrate 10 using a liquid metal alloy as the substrate; including gallium, indium , bismuth, tin, zinc and other alloys, for example: gallium indium tin alloy, indium bismuth tin alloy, or indium bismuth zinc alloy, etc., but not limited to this. In a feasible embodiment, the liquid gallium-based metal alloy is used as the substrate 10, and the bulk metal gallium can be heated to 100°C and melted into a liquid state with high-purity gallium, high-purity indium, and high-purity tin, and the purity of the three is 99.9999%. Weigh gallium (68.5%), indium (21.5%), and tin (10%) by mass ratio, place the above-mentioned raw materials in a plastic container, and heat them in warm water at 60°C Stir until the metal indium and tin are completely dissolved, and a liquid gallium-based alloy can be obtained, which is a gallium indium tin ternary alloy with a melting point of about 10° C., but is not limited to this.

A nano-scale high thermal conductivity powder 20 is dissolved in the thermally conductive substrate 10 with particles having an average size of 10 nm˜10 μm, and the thermally conductive substrate 10 is viscous and phase-changed into a solid metal thermally conductive sheet 30 , the thickness (t ₁ ) 0.3cm~0.5cm; and the solid metal thermally conductive sheet 30 is placed on the surface of a heat source 40, and the heated phase change extends into a metal thermally conductive adhesive thin layer structure 30a with a thickness (t ₂ ) less than 0.3cm.

In this embodiment, when the temperature of the heat source 40 is greater than 58° C., the solid metal thermally conductive sheet 30 begins to undergo a phase change, and extends into the metal thermally conductive adhesive thin layer structure 30a in the form of a paste or a glue solid. The non-liquid thin-layered structure has excellent adhesion and can be uniformly combined on the surface of the heat source 40 without the phenomenon of solid-liquid separation. In addition, as shown in FIG. 4 , after the surface layer of the solid metal thermal conductive sheet 30 is oxidized 31 , it can also become a metal thermal conductive adhesive thin layer structure 30 a with excellent adhesion on the surface, which is the same as the process of phase change and can be uniformly combined on the surface of the heat source 40 .

In this embodiment, the heat source 40 includes a semiconductor chip, and a heat sink 50 is correspondingly provided on the semiconductor chip 40 .

In this embodiment, the nano-scale high thermal conductivity powder 20 may have a circular or quasi-circular particle structure, preferably a particle structure with an average size of less than 10 μm, but is not limited thereto. And the nano-scale high thermal conductivity powder 20 includes particles composed of metal powder or non-metal powder, such as: gold (Au), silver (Ag), plastic microbeads, glass microbeads, alumina, silicon carbide, nitride Materials such as boron can be implemented.

In this embodiment, the contact surface of the heat sink 50 and the composite thermally conductive adhesive structure layer 30 further includes an anti-corrosion layer 51 . The anti-corrosion layer 51 includes, but is not limited to, nickel metal. Nickel metal has excellent corrosion resistance and can be attached to the heat sink 50 by electroplating or coating techniques. In this way, the heat sink 50 is not easily affected by the metal conduction. The erosion of the material of the hot glue thin layer structure 30a can ensure its service life and reliability. The semiconductor chip 40 and the heat sink 50 are prior art, which are not the subject of the patent of this creation, and will not be described in detail.

In this embodiment, the semiconductor chip 40 is disposed on the circuit board 41 , and the circuit board 41 is provided with a retaining wall 42 surrounding the semiconductor chip 40 . Although the metal thermally conductive adhesive thin layer structure 30a of the present invention is in the form of a paste or a glue solid, it is not easy for liquid to leak out and cause a short circuit problem. However, for the sake of 100% safety, if the semiconductor chip 40 is abnormally overheated, causing the metal thermally conductive adhesive thin layer structure 30a to be softened, the retaining wall 42 can ensure that the liquid will not leak out and cause a short circuit. problem with double security.

The main differences between this creation and the conventional "liquid metal" thermal conductive material and "traditional thermal paste" are as follows:

1. In this creation, metal or inorganic non-metallic powder is added to the liquid metal, and a solid metal thermal conductive sheet 30 is formed after vigorous stirring, which can reduce the fluidity of the liquid metal, and facilitate and significantly improve its wettability on various substrates; this The conventional "liquid metal" thermal conductive material cannot achieve it. When the conventional "liquid metal" reaches the phase change temperature, its fluidity is greatly improved, and it is easy to overflow and contaminate electronic components. This work can effectively improve this problem. point. Because the metal thermally conductive adhesive thin-layer structure 30a is a paste or a solid at room temperature, which is completely different from the conventional "liquid metal" thermally conductive material, so there is no need to worry about the liquid leaking out and causing a short circuit, and thus has safety and stability. efficacy increased.

2. The solid metal thermally conductive sheet 30 of the present invention is conveniently placed on the heat source 40, and through the phase change or oxidation process, the thin-layered metal thermally conductive adhesive thin-layer structure 30a can be smoothly extended on the wafer, and has excellent adhesion and gap filling, and as shown in FIG. 6 , the thickness (t2) of the metal thermally conductive adhesive thin-layer structure 30a can be less than 0.3 cm. Since the thickness of the metal thermally conductive adhesive thin-layer structure 30a is as thin as possible, the solid state of the present invention Metal thermal conductive sheet 30, to solve the fluidity or extension of traditional thermal paste The disadvantage is that the thermal paste is too thick due to poor thermal conductivity. The operation process will not damage the chip, and the thin-layered metal thermal paste thin layer structure 30a can reduce thermal resistance, improve heat dissipation, and improve safety and stability.

3. The metal thermally conductive adhesive thin layer structure 30a is in the form of a paste or a glue Solid), not a rigid body or a solid body, so it has elasticity, and it is arranged between the semiconductor chip 40 and the heat sink 50, not only can the interface between the semiconductor chip 40 and the heat sink 50 be closely attached, significantly Reduce the contact thermal resistance between the semiconductor chip 40 and the heat sink 50; and because of its elasticity, an elastic buffer force can be provided between the semiconductor chip 40 and the heat sink 50, so that the semiconductor chip 40 is not easily affected The pressure of the heat sink 50 causes damage.

With the help of the above-mentioned technical means, the thin layer structure 30a of metal thermally conductive adhesive in this creation can simultaneously solve the deficiencies caused by the conventional "liquid metal" thermally conductive material and the "traditional thermally conductive paste". The defect caused by the "liquid metal" thermal conductive material and the "traditional thermal conductive paste"; with the structure of the solid metal thermal conductive sheet 30, after reaching the phase change temperature, it forms a solid or paste, which is completely filled in the interface with gaps to become A good interface material can smoothly spread on the wafer 40 in a thin layer, and can be evenly combined on the surface of the heat source 40 without solid-liquid separation. Adhesive can reduce thermal resistance, and has multiple functions such as good heat dissipation, safety and stability.

To sum up, the structure disclosed in this creation is unprecedented, and can indeed achieve the improvement of efficacy, and is available for industrial use, and fully meets the requirements of a new type of patent. , without any sense of virtue.

However, the drawings and descriptions disclosed above are only the preferred embodiments of the present creation, and modifications or equivalent changes made by those familiar with the art in accordance with the spirit of the present case should still be included in the scope of the patent application of the present case.

30: Solid metal thermal conductive sheet

40: heat source (semiconductor wafer)

41: circuit board

42: Retaining Wall

50: Radiator

51: Anti-corrosion layer

Claims (4)

A metal heat-conducting thin sheet structure with particles and phase changes, comprising: a heat-conducting matrix, using a liquid metal alloy as the matrix; a nano-scale high heat-conducting powder, in the form of particles with an average size of 10nm-10μm, dissolved in the heat-conducting matrix, The thermal conductive substrate is phase-changed into a solid metal thermally conductive sheet with a thickness of 0.3cm-0.5cm; the solid metal thermally conductive sheet is placed on the surface of a heat source, and the heated phase change extends into a thin metal thermally conductive adhesive with a thickness of less than 0.3cm. Layer structure; the heat source includes a semiconductor chip, and a radiator is correspondingly arranged on the semiconductor chip; and a contact surface between the radiator and the solid metal heat-conducting sheet further includes an anti-corrosion layer. The structure of the thermally conductive metal sheet with particles and phase change as described in item 1 of the claimed scope, wherein when the temperature of the heat source is greater than 58° C., the solid thermally conductive metal sheet undergoes a phase change. The metal thermally conductive sheet structure with particles and phase change as described in claim 1, wherein the nanoscale high thermal conductivity powder is a circular or quasi-circular particle structure. The metal thermally conductive thin sheet structure with particles and phase change as described in claim 1, wherein the nanoscale high thermal conductivity powder includes particles composed of metal powder or non-metallic powder.

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