Patent Description:
This application relates to the field of electronic device technologies, and in particular, to a method for manufacturing a heat dissipation structure of an electronic element, a heat dissipation structure, and an electronic device.

With the advance of technologies, electronic devices gradually develop toward miniaturization, lightness, and high performance. Integration of electronic elements in an electronic device is increasingly high, and power consumption is also increasingly high. Increasing power consumption of the electronic element causes a large amount of heat in a running process of the electronic element. When the heat causes an excessive temperature of the electronic element, a running speed of the electronic element is affected, and therefore, a problem occurs during running of the electronic device.

A heat dissipation manner of the electronic element is that heat is transmitted to a heat sink in a heat conduction manner by using the heat sink in close contact with the electronic element, and then heat reaching the heat sink is dissipated to the environment by using a fan or the like. Inevitably, there is a gap at a contact surface between the electronic element and the heat sink. Air in the gap is a poor heat conductor, and affects heat transfer to the heat sink. Therefore, the gap needs to be filled with a thermally conductive medium, so that heat conduction is smoother and quicker.

In the conventional technology, a thermally conductive medium that is liquid (for example, a liquid metal heat conductor, usually referred to as liquid metal for short) at a normal temperature (also referred to as a common temperature or an indoor temperature and usually defined as <NUM>) is usually used to fill the foregoing gap. In a thermally conductive medium filling process in a processing step, the liquid thermally conductive medium needs to be injected by using a glue dispenser. In this filling process, a dedicated device such as the glue dispenser needs to be purchased. In addition, to avoid leakage of the liquid thermally conductive medium, process stability of the filling process needs to be high. Therefore, device costs and processing costs in the processing step increase, and production efficiency is affected.

<CIT> discloses a structure including a heat dissipating electronic device, which is attached to a heatsink with a stack of sheet like members placed therebetween. This stack particularly comprises a phase shift thermally conductive material which is attached to the heatsink before placing the heat sink on top of the heat dissipating electronic device and attaching the same to a substrate on which the electronic device is mounted.

<CIT> discloses a heat dissipation structure for dissipating heat produced in a terminal device. A housing in which a heat dissipating electronic component is mounted is provided adjacent to the heat dissipating component and a gap formed between the housing and the heat dissipating element is filled with a thermal conductor including at least a first thermally conductive layer comprising a phase change material. The electronic device and the thermal conductor are surrounded by a shield frame attached, as the heat generating electronic device, to a substrate arranged in the housing.

<CIT> discloses a structure in which a heat generating electronic component is attached by a phase change material pad to a PCB supporting copper pads on which the phase change material pad is placed. On the other side of the die, a connector is arranged between the die and a substrate.

A structure including a heat dissipating element and a heatsink is also known from <CIT>. In the structure, the surface of the heat sink which faces the heat dissipating electronic elements, is divided using protrusions protruding from the surface facing the heat dissipating element into an inner area and an outer area. The outer area forms a flange attached to an adhesive material holding the heatsink on the heat dissipating surface of the electronic device. The inner area, which is completely surrounded by the protrusions on the heatsink, accommodates a thermally conductive material.

This application provides a method for manufacturing a heat dissipation structure of an electronic element, a heat dissipation structure, and an electronic device. The invention is defined in the appended independent claims. Advantageous aspects and features are defined in the dependent claims. A thermally conductive material that is in a solid state at a normal temperature is used and is placed between an electronic element and a heat sink. When the electronic element works, the solid-state thermally conductive material melts to a liquid state, to fill a gap between the electronic element and the heat sink and establish a thermally conductive channel between the electronic element and the heat sink. Because the solid-state thermally conductive material is used, a glue dispensing station is not required in a filling process. This simplifies steps and devices in the filling process and reduces processing difficulty, and then improves production efficiency and reduces production and manufacturing costs.

According to a first aspect, this application provides a method for manufacturing a heat dissipation structure of an electronic element, including:.

According to the method for manufacturing a heat dissipation structure of an electronic element in this application, the phase-change thermally conductive material that is in a solid state in the preset temperature condition is selected, and the phase-change thermally conductive material can be directly picked up manually or by using a mechanical hand to perform a filling operation, so that a filling process can be completely free of dependence on a glue dispensing station. In this way, steps and devices in the filling process are simplified, and production and manufacturing costs of the heat dissipation structure are reduced. In addition, because a liquid phase-change thermally conductive material is no longer used, a process control requirement on horizontality and stability of the substrate in the filling process is reduced. In this case, costs of process control software and hardware such as a sensor and a controller on a corresponding production line can be reduced, and production and manufacturing efficiency can be further improved.

In addition, the heat dissipation cover is connected to the substrate and surrounds the electronic element. In this application, the heat dissipation cover has a heat dissipation function and a function of preventing leakage of a melted phase-change thermally conductive material, so that the heat dissipation cover has a "one-cover multiple-use" effect. Production and manufacturing costs of the heat dissipation structure are reduced, and a heat dissipation structure design is optimized. Compared with that in a conventional manner in which a silica gel ring and a foam are used to seal a phase-change thermally conductive material, in a case of a same thickness, the heat dissipation cover provides a larger accommodation cavity, and more phase-change thermally conductive materials can be placed. This is more conducive to lightness development of the electronic device.

In addition, the heat dissipation cover is directly connected to the substrate to form the accommodation cavity. Compared with that in a conventional manner in which a silica gel ring and a foam are pressed on a surface of an electronic element, a risk of pressure damage to the electronic element can be avoided.

Optionally, the electronic element and the substrate may be welded together by using a wire or a contact, or may be connected in an attaching manner.

Optionally, the solid-state phase-change thermally conductive material may be directly picked up and placed manually or by using a mechanical hand.

Optionally, the solid-state phase-change thermally conductive material is placed in the accommodation cavity surrounded by the substrate and the heat dissipation cover. According to an alternative example not covered by the claims, the periphery of the electronic element may be pre-covered with the heat dissipation cover, and then the solid-state phase-change thermally conductive material is placed in the accommodation cavity. Alternatively, an opening may be disposed on a top wall of the heat dissipation cover, the heat dissipation cover covers the periphery of the electronic element and is fixedly connected to the substrate, and then the solid-state phase-change thermally conductive material is placed in the accommodation cavity through the opening.

Optionally, the heat dissipation cover and the substrate may be connected in a manner such as attaching, sticking, welding, bolting, or clamping, to implement a fixed connection between the heat dissipation cover and the substrate.

Optionally, sealing may be performed at a joint between the heat dissipation cover and the substrate, and a sealing adhesive is applied or a sealing ring is pressed at the joint between the heat dissipation cover and the substrate.

Optionally, a manner of attaching a heat dissipation module and the heat dissipation cover is as follows: A bottom area of the heat dissipation module is set to be greater than an area of the top wall of the heat dissipation cover, a periphery of the heat dissipation module is bolted to the substrate, and a middle part of the heat dissipation module is pressed onto the heat dissipation cover. Alternatively, the heat dissipation module is directly attached to the heat dissipation cover in a manner such as sticking, welding, or bolting.

A purpose of adding the heat dissipation module is as follows: Compared with a separate heat dissipation cover, the added heat dissipation module can provide more diversified technical solutions for fast heat dissipation. For example, when the electronic device is a mobile phone, the heat dissipation module is a metal support part of a battery or a screen, and heat can be quickly exported from the inside of the mobile phone to the outside and emitted to the environment.

the covering a periphery of the electronic element with a heat dissipation cover, fixedly connecting the heat dissipation cover to the substrate, and placing a solid-state phase-change thermally conductive material in an accommodation cavity surrounded by the substrate and the heat dissipation cover includes:.

The phase-change thermally conductive material and the heat dissipation cover form the integrated structure. When the electronic element is covered, the phase-change thermally conductive material does not need to be placed separately, so that an operation such as positioning or adjustment required when the phase-change thermally conductive material is placed in the accommodation cavity is avoided, thereby further reducing process control difficulty and improving production efficiency.

An opening is disposed on the top wall, an avoidance hole is disposed on the sheet-like structure, and the manufacturing method further includes:
attaching a heat dissipation module to the top wall, and enabling a protruding thermally conductive column on an outer wall of the heat dissipation module to sequentially pass through the opening and the avoidance hole and extend into the accommodation cavity. The heat dissipation module is directly in contact with the phase-change thermally conductive material by using the thermally conductive column, so that a spacing between the electronic element and the heat dissipation module can be smaller. This reduces a length of a heat transfer path, reduces heat transfer resistance, and facilitates an ultra-thin design of the electronic device.

Optionally, a manner of constructing the phase-change thermally conductive material into the sheet-like structure may be mechanical pressing, pouring after heating and melting, or the like.

Optionally, the phase-change thermally conductive material of the sheet-like structure may be sticked to the inner surface of the top wall of the heat dissipation cover by using a hot melt adhesive or another adhesive.

Optionally, a production manner of the heat dissipation cover may be metal stamping.

When stamping is performed on the heat dissipation cover, and the phase-change thermally conductive material is constructed into a sheet, the opening is directly disposed on the heat dissipation cover, the avoidance hole is disposed on the sheet-like phase-change thermally conductive material, and the opening and the avoidance hole are disposed directly opposite each other. Then, the heat dissipation cover is sticked to the phase-change thermally conductive material.

Optionally, after the heat dissipation cover and the phase-change thermally conductive material are sticked into an integrated structure, a hole may be disposed on the integrated structure, to synchronously form the opening and the avoidance hole that are disposed directly opposite each other.

In a possible design, the preset temperature condition is <NUM>~<NUM>. An average annual indoor temperature in most regions can meet the preset temperature condition. Therefore, the manufacturing method is widely used.

In a possible design, a melting point of the phase-change thermally conductive material is <NUM>~<NUM>.

Optionally, the foregoing phase-change thermally conductive material may be an organic phase-change material, an inorganic phase-change material, or a composite phase-change material.

Specifically, paraffin or fatty acid may be used as the organic phase-change material.

Specifically, the inorganic phase-change material may be a paraffin/graphene composite phase-change material. Organic paraffin is used as a phase-change material, and expanded graphite is used as a support structure, to form the composite phase-change material.

Specifically, the inorganic phase-change material may be crystalline hydrated salt, molten salt, a metal material, or another inorganic substance.

In a possible design, the phase-change thermally conductive material is a metal material.

In a possible design, the phase-change thermally conductive material includes a gallium-based alloy, an indium-based alloy, or a bismuth-based alloy.

For example, the gallium-based alloy may be a gallium-indium alloy, a gallium-lead alloy, a gallium-mercury alloy, a gallium-indium-tin alloy, or a gallium-indium-tin-zinc alloy.

For example, the indium-based alloy may be an indium-bismuth-copper alloy or an indium-bismuth-tin alloy.

For example, the bismuth-based alloy may be a bismuth-tin alloy.

In a possible design, the heat dissipation cover is a metal cover. The metal cover has a good heat conduction effect and a good shielding effect. In addition, when the heat dissipation cover is the metal cover, pick-up and transfer may be performed by using a magnetic mechanical arm. This facilitates an operation in an assembly step.

Optionally, a material of the heat dissipation cover is stainless steel, a copper-nickel-zinc alloy, a magnesium-aluminum alloy, or the like.

In a possible design, the heat dissipation module has a heat dissipation fin or a heat dissipation grille. This can increase a heat exchange area with air, and improve heat dissipation efficiency.

According to a second aspect, this application further provides a heat dissipation structure of an electronic element, including:.

In the heat dissipation structure of the electronic element provided in this application, the phase-change thermally conductive material whose melting point is <NUM>~<NUM> is selected. A melting point temperature of the phase-change thermally conductive material is higher than <NUM> that is a normal temperature. Therefore, the phase-change thermally conductive material is in a solid state at the normal temperature, and can be directly picked up manually or by using a mechanical hand to perform a filling operation, so that a filling process can be free of dependence on a glue dispensing station. In this way, steps and devices in the filling process are simplified, and production and manufacturing costs of the heat dissipation structure are reduced.

Optionally, anti-seepage glue is applied to an inner surface of a peripheral wall and an inner surface of a top wall that are of the heat dissipation cover and an upper surface of the electronic element, that is, positions in contact with the phase-change thermally conductive material.

A size of the accommodation cavity formed between the heat dissipation cover and the substrate may be determined according to a size of the substrate. When a large accommodation cavity is needed, a substrate with a large size may be disposed. Alternatively, a size of the accommodation cavity may be determined according to power consumption of the electronic element. When power consumption of the electronic element is relatively high, the accommodation cavity <NUM> may be relatively large, to accommodate more phase-change thermally conductive materials.

In addition, for the electronic device, the electronic element may be disposed on the substrate, and a size of the substrate may be determined according to a size of the electronic device and a heat dissipation performance requirement.

the heat dissipation structure further includes a heat dissipation module attached to a top wall of the heat dissipation cover.

Optionally, the heat dissipation cover may be in a ring shape, and surrounds the electronic element in a structure similar to a dam, the top of the heat dissipation cover is open, and the heat dissipation module covers the opening of the heat dissipation cover.

An opening is disposed on the top wall, a thermally conductive column protrudes from an outer wall of the heat dissipation module, and the thermally conductive column passes through the opening and extends into the accommodation cavity.

Optionally, sealing may be performed at an insertion position between the thermally conductive column and the opening, or sealing may not be performed. This may be selected according to different application scenarios.

Optionally, only one thermally conductive column may be disposed, that is, a large round-table structure. In this case, a corresponding opening is a large round hole, and the round table passes through the round hole and extends into the accommodation cavity.

In a possible design, there are a plurality of thermally conductive columns spaced from each other, and the plurality of thermally conductive columns pass through a plurality of openings in a one-to-one correspondence and extend into the accommodation cavity.

In a possible design, the heat dissipation cover is a metal cover.

In a possible design, the heat dissipation module has a heat dissipation fin or a heat dissipation grille.

In a possible design, a plurality of electronic elements are disposed on the substrate, and the heat dissipation cover surrounds the plurality of electronic elements. A single heat dissipation cover is corresponding to a plurality of electronic elements, so that costs of a production process and a mounting process of the heat dissipation cover can be reduced, thereby reducing manufacturing costs of the heat dissipation structure in this application.

In a possible design, a melting point of the phase-change thermally conductive material is <NUM>~<NUM>. During actual production and application, it is found that the melting point should not be too low or too high. If the melting point is too low, the phase-change thermally conductive material is easy to liquefy and inconvenient to assemble. Therefore, strict temperature control is needed for an assembly environment, and this increases production and manufacturing costs. If the melting point is too high, the phase-change thermally conductive material cannot liquefy easily, and this affects heat conduction. If the electronic element works at a temperature close to the melting point for a long time, functional damage of the electronic element is caused, and a service life of the electronic element is reduced.

According to a third aspect, this application further provides an electronic device, including the foregoing heat dissipation structure.

Optionally, the electronic device is any one of a desktop computer, a notebook computer, a tablet computer, a game console, a mobile phone, an electronic watch, a router, a set-top box, a television, and a modem.

Reference numerals: <NUM>. substrate; <NUM>. electronic element; <NUM>. heat dissipation cover; <NUM>. opening; <NUM>. heat dissipation module; <NUM>. thermally conductive column; <NUM>. heat dissipation grille; <NUM>. phase-change thermally conductive material; <NUM>. avoidance hole; <NUM>. accommodation cavity; <NUM>. electronic device; <NUM>. silica gel ring; <NUM>. foam; <NUM>. liquid metal; <NUM>. heat sink; <NUM>. heat dissipation structure.

It is clear that the described embodiments are merely some but not all of embodiments of this application.

In the descriptions of this application, it should be noted that, unless otherwise specified and limited, the terms "mount", "connection", and "connect" should be understood in a broad sense, for example, may indicate a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, mutual communication, a direct connection, an indirect connection through an intermediate medium, an internal connection between two elements, or an interaction relationship between two elements. A person of ordinary skill in the art may understand a specific meaning of the foregoing term in this application according to a specific situation.

In the descriptions of this application, it should be understood that an orientation relationship or a position relationship indicated by terms "up", "down", "side", "in", "out", "top", and "bottom" are an orientation relationship or a position relationship based on mounting, and is merely for ease of description and simplification of this application, but is not intended to indicate or imply that a specified apparatus or element necessarily has a specific orientation or is constructed and operated in a specific orientation. Therefore, the terms should not be construed as a limitation on this application.

It should be further noted that in embodiments of this application, a same reference numeral indicates a same part or a same component. For a same component or part in embodiments of this application, only one component or part may be marked with a reference numeral in the figure as an example. It should be understood that, for another same component or part, the reference numeral is also applicable.

In the descriptions of this application, it should be noted that the term "and/or" is merely an association relationship for describing associated objects, and indicates that three relationships may exist. For example, A and/or B may indicate the following three cases: Only A exists, both A and B exist, and only B exists.

An electronic element is a basic element in an electronic circuit, and has two or more leads or metal contacts. After being connected to each other, electronic elements may constitute an electronic circuit with a specific function. A common manner of connecting the electronic elements is welding onto a substrate. The electronic element may be an individual package, such as a resistor, a capacitor, an inductor, a transistor, or a diode, or may be various groups with different complexity, such as an integrated circuit (Integrated Circuit, IC).

An electronic device is a device that includes a plurality of types of electronic elements such as an integrated circuit, a transistor, and an electronic tube and functions by using electronic technology software, for example, a desktop computer, a notebook computer, a tablet computer, a game console, a mobile phone, an electronic watch, a router, a set-top box, a television, or a modem.

When the electronic device works, heat is generated, causing a rapid increase in an internal temperature of the device. A direct reason is power consumption of the electronic element. All electronic elements have power consumption of different degrees, and heating intensity of the electronic element changes with power consumption. If the heat is not dissipated in a timely manner, the electronic element continuously heats up, and finally fails due to overheating, resulting in reduced functional stability of the electronic device and even a complete failure of a function. In addition, as the electronic device gradually develops toward miniaturization, lightness, and high performance, integration of electronic elements in the electronic device is also increasingly high, and power consumption is increasingly high. How to rapidly and effectively emit heat generated by the electronic element is a key problem to be resolved for the electronic device developing toward miniaturization, lightness, and high performance.

Currently, a heat dissipation manner of the electronic element is that heat is transmitted to a heat sink in a heat conduction manner by using the heat sink in close contact with the electronic element, and then heat reaching the heat sink is dissipated to the environment by using a fan or the like. On a contact surface between the electronic element and the heat sink, it seems that the contact is good, but actually, an area of direct contact is small, and the remaining part is a gap. Thermal resistance of gas in the gap (the thermal resistance refers to resistance of heat on a heat flow path, and reflects a heat transfer capability of a medium or between media) is relatively large, and a heat conduction capability is extremely weak. This greatly impedes heat transfer from the electronic element to the heat sink. Therefore, the gap needs to be filled with a thermally conductive medium, so that heat conduction is smoother and quicker.

In the conventional technology, a thermally conductive medium that is in a liquid state at a normal temperature is usually used to fill the gap, for example, liquid metal. Therefore, during processing of a heat dissipation structure of the electronic element, a glue dispensing station needs to be added in a filling process to put the liquid thermally conductive medium.

<FIG> is a schematic diagram of a method for manufacturing a heat dissipation structure of an electronic element <NUM> in the conventional technology. (a) in <FIG> is a schematic diagram in which the electronic element <NUM> is on a substrate <NUM> and is not processed, (b) in <FIG> is a schematic diagram in which a silica gel ring <NUM> and a foam <NUM> are mounted on the electronic element <NUM>, (c) in <FIG> is a schematic diagram in which a liquid thermally conductive medium is dispensed, and (d) in <FIG> is a schematic diagram in which a heat sink <NUM> is pressed on a surface of the electronic element <NUM>. <FIG> is a cross-sectional view of a heat dissipation structure of the electronic element <NUM> in the conventional technology, that is, a cross-sectional view of (d) in <FIG>.

For example, liquid metal <NUM> is used for filling. A process step of placing the liquid metal <NUM> between the electronic element <NUM> and the heat sink <NUM> is as follows: In a first step, as shown in (a) and (b) in <FIG>, the silica gel ring <NUM> and the foam <NUM> are mounted on the surface of the electronic element <NUM> disposed on the substrate <NUM>. In a second step, as shown in (c) in <FIG>, the liquid metal <NUM> is dispensed on the surface of the electronic element <NUM> and in an enclosure ring of the silica gel ring <NUM> and the foam <NUM> by using a glue dispensing station. In a third step, as shown in (d) in <FIG>, the metal heat sink <NUM> is pressed over the silica gel ring <NUM> and the foam <NUM>, and the liquid metal <NUM> is sealed in space surrounded by the silica gel ring <NUM>, the electronic element <NUM>, and the heat sink <NUM>.

When the liquid metal <NUM> is dispensed in the second step, there are two manners: One is a two-step manner. The electronic element <NUM> is first brushed with the liquid metal <NUM> by using a silica gel brush, then the liquid metal <NUM> is injected by using a needle tube, and liquid drops are naturally spread on the surface of the electronic element <NUM>. The other is to directly perform glue dispensing in a specified region by using a glue dispenser.

In actual production, it is found that using the liquid metal <NUM> as a thermally conductive medium to manufacture the heat dissipation structure has the following problems. First, a glue dispensing station needs to be added, and therefore, a corresponding device needs to be purchased and a process is prolonged, resulting in a complex process route and high costs. Second, the liquid metal <NUM> has relatively high weight and fluidity. If horizontality and stability of the substrate <NUM> cannot be ensured during glue dispensing, the liquid metal <NUM> is prone to overflow. To ensure that the liquid metal <NUM> does not overflow during glue dispensing, only semi-automatic filling can be implemented at present. Therefore, the existing process not only requires relatively high process stability, but also causes a decrease in production efficiency. Third, it is difficult to control the process. Specifically, when the metal heat sink <NUM> is pressed, to ensure sealing of the heat dissipation structure and prevent leakage of the liquid metal <NUM>, a relatively large pressing force is required. In this case, the electronic element <NUM> is at a risk of failure. If the pressing force is relatively small, sealing of the heat dissipation structure cannot be ensured. Therefore, the pressing force needs to be accurately controlled.

In conclusion, the existing heat dissipation structure of the electronic element <NUM> and the existing method for manufacturing the heat dissipation structure are characterized by a complex process route and a high requirement for process stability and control. Therefore, manufacturing costs of the heat dissipation structure of the electronic element <NUM> are high, and production efficiency is low.

To resolve the foregoing technical problem, this application provides a method for manufacturing a heat dissipation structure of an electronic element <NUM>, a heat dissipation structure, and an electronic device. A thermally conductive material that is in a solid state at a normal temperature is used and is placed between the electronic element <NUM> and a heat sink <NUM>. When the electronic element <NUM> works, the solid-state thermally conductive material melts to a liquid state, to fill a gap between the electronic element <NUM> and the heat sink <NUM> and establish a thermally conductive channel between the electronic element <NUM> and the heat sink <NUM>. Because the solid-state thermally conductive material is used, a glue dispensing station is not required in a filling process. This simplifies steps and devices in the filling process and reduces processing difficulty, and then improves production efficiency and reduces production and manufacturing costs.

An embodiment of this application provides a method for manufacturing a heat dissipation structure of an electronic element <NUM>. <FIG> is a flowchart of a method for manufacturing a heat dissipation structure of an electronic element <NUM> according to an alternative example not covered by the claims. As shown in <FIG>, the manufacturing method includes the following steps.

Step <NUM>: Place a substrate <NUM> having the electronic element <NUM> in an environment that meets a preset temperature condition.

Step <NUM>: In the environment that meets the preset temperature condition, cover a periphery of the electronic element <NUM> with a heat dissipation cover <NUM>, fixedly connect the heat dissipation cover <NUM> to the substrate <NUM>, and place a solid-state phase change thermally conductive material <NUM> in an accommodation cavity <NUM> surrounded by the substrate <NUM> and the heat dissipation cover <NUM>.

According to the method for manufacturing a heat dissipation structure of an electronic element <NUM> in this embodiment of this application, the phase-change thermally conductive material <NUM> that is in a solid state in the preset temperature condition is selected, and the phase-change thermally conductive material <NUM> can be directly picked up manually or by using a mechanical hand to perform a filling operation, so that a filling process can be completely free of dependence on a glue dispensing station. In this way, steps and devices in the filling process are simplified, and production and manufacturing costs of the heat dissipation structure are reduced. In addition, because a liquid phase-change thermally conductive material <NUM> is no longer used, a process control requirement on horizontality and stability of the substrate <NUM> in the filling process is reduced. In this case, costs of process control software and hardware such as a sensor and a controller on a corresponding production line can be reduced, and production and manufacturing efficiency can be further improved.

In addition, the heat dissipation cover <NUM> is connected to the substrate <NUM> and surrounds the electronic element <NUM>. In this application, the heat dissipation cover has a heat dissipation function and a function of preventing leakage of a melted phase-change thermally conductive material <NUM>, so that the heat dissipation cover <NUM> has a "one-cover multiple-use" effect. Production and manufacturing costs of the heat dissipation structure are reduced, and a heat dissipation structure design is optimized. Compared with that in a conventional manner in which a silica gel ring <NUM> and a foam <NUM> are used to seal a phase-change thermally conductive material <NUM>, in a case of a same thickness, the heat dissipation cover <NUM> provides a larger accommodation cavity <NUM>, and more phase-change thermally conductive materials <NUM> can be placed. This is more conducive to lightness development of the electronic device.

In addition, the heat dissipation cover <NUM> is directly connected to the substrate <NUM> to form the accommodation cavity <NUM>. Compared with that in a conventional manner in which a silica gel ring <NUM> and a foam <NUM> are pressed on a surface of an electronic element <NUM>, a risk of pressure damage to the electronic element <NUM> can be avoided.

Optionally, the electronic element <NUM> and the substrate <NUM> may be welded together by using a wire or a contact, or may be connected in an attaching manner, thereby implementing integration of the electronic element <NUM> and the substrate <NUM>.

Optionally, the solid-state phase-change thermally conductive material <NUM> may be directly picked up and placed manually or by using a mechanical hand.

Optionally, the solid-state phase-change thermally conductive material <NUM> may be placed, in a plurality of manners, in the accommodation cavity <NUM> surrounded by the substrate <NUM> and the heat dissipation cover <NUM>. For example, in manner <NUM>, the periphery of the electronic element <NUM> is pre-covered with the heat dissipation cover <NUM>, then the solid-state phase-change thermally conductive material <NUM> is placed in the accommodation cavity <NUM>, and finally the heat dissipation cover <NUM> is fixedly connected to the substrate <NUM>. In manner <NUM>, an opening <NUM> is disposed on a top wall of the heat dissipation cover <NUM>, the heat dissipation cover <NUM> covers the periphery of the electronic element <NUM> and is fixedly connected to the substrate <NUM>, then the solid-state phase-change thermally conductive material <NUM> is placed in the accommodation cavity <NUM> through the opening <NUM>, and finally the opening <NUM> is sealed. In manner <NUM>, the solid-state phase-change thermally conductive material <NUM> may be integrated inside the heat dissipation cover <NUM>, to form an integrated structure, and then the heat dissipation cover <NUM> is used for covering and is fixedly connected to the substrate <NUM>. In this case, the solid-state phase-change thermally conductive material <NUM> is already disposed in the accommodation cavity <NUM>.

Optionally, the heat dissipation cover <NUM> and the substrate <NUM> may be connected in a manner such as attaching, sticking, welding, bolting, or clamping, to implement a fixed connection between the heat dissipation cover <NUM> and the substrate <NUM>. The heat dissipation cover <NUM> fastened to the substrate <NUM> is disposed around the periphery of the electronic element <NUM>.

Optionally, sealing may be performed at a joint between the heat dissipation cover <NUM> and the substrate <NUM>, for example, a sealing adhesive is applied or a sealing ring is pressed at the joint between the heat dissipation cover <NUM> and the substrate <NUM>, to prevent leakage of the phase-change thermally conductive material <NUM>.

Optionally, to improve a heat dissipation effect of the heat dissipation cover <NUM>, a heat dissipation fin structure, a heat dissipation bump structure, a heat dissipation wave structure, or the like may be disposed on an outer surface of the heat dissipation cover <NUM>, to increase a heat exchange area on the outer surface of the heat dissipation cover <NUM>, and then quickly emit heat from the electronic element <NUM> to the environment. Alternatively, a fan is added to the outside of the heat dissipation cover <NUM>, and an airflow direction of the fan faces the heat dissipation cover <NUM>. Heat from the electronic element <NUM> is quickly removed from the heat dissipation cover <NUM> in an air cooling manner.

As shown in <FIG>, in the manufacturing method in this embodiment of this application, step <NUM> may be further added to attach a heat dissipation module <NUM> to the heat dissipation cover <NUM>.

A purpose of adding the heat dissipation module <NUM> in this embodiment is as follows: Compared with a separate heat dissipation cover <NUM>, the added heat dissipation module <NUM> can provide more diversified technical solutions for fast heat dissipation. For example, a heat dissipation module <NUM> including a heat dissipation fin or a heat dissipation grille <NUM> can provide a larger heat exchange area than the heat dissipation cover <NUM>. The heat dissipation module <NUM> may further be a metal support of a functional element in the electronic device. For example, when the electronic device is a mobile phone, the heat dissipation module <NUM> is a metal support part of a battery or a screen, and heat can be rapidly exported from the inside of the mobile phone to the outside and emitted to the environment.

Specifically, a manner of attaching the heat dissipation module <NUM> and the heat dissipation cover <NUM> is as follows: A bottom area of the heat dissipation module <NUM> is set to be greater than an area of the top wall of the heat dissipation cover <NUM>, a periphery of the heat dissipation module <NUM> is bolted to the substrate <NUM>, and a middle part of the heat dissipation module <NUM> is pressed onto the heat dissipation cover <NUM>. Alternatively, the heat dissipation module <NUM> is directly attached to the heat dissipation cover <NUM> in a manner such as sticking, welding, or bolting.

It should be noted that, in some scenarios, the heat dissipation cover <NUM> may be disposed separately. After heat of the electronic element <NUM> is conducted to the heat dissipation cover <NUM> by using the phase-change thermally conductive material <NUM>, the heat is emitted to the environment by using the heat dissipation cover <NUM>. In some other scenarios, the heat dissipation cover <NUM> may include the heat dissipation module <NUM>, that is, the heat dissipation cover <NUM> and the heat dissipation module <NUM> are an integrated structure. In this case, the top wall of the heat dissipation cover <NUM> is a bottom wall of the heat dissipation module <NUM>, and heat of the electronic element <NUM> is transmitted to the heat dissipation module <NUM> by using the phase-change thermally conductive material <NUM>, and then is emitted to the environment by using the heat dissipation module <NUM>. In some other scenarios, the heat dissipation cover <NUM> and the heat dissipation module <NUM> are separated structures, and the top wall of the heat dissipation cover <NUM> is attached to a bottom wall of the heat dissipation module <NUM> in a manner such as sticking, welding, or bolting. In this case, heat of the electronic element <NUM> is conducted to the heat dissipation cover <NUM> by using the phase-change thermally conductive material <NUM>, then the heat dissipation cover <NUM> transfers the heat to the heat dissipation module <NUM>, and the heat is emitted to the environment by using the heat dissipation module <NUM>.

<FIG> is a flowchart of another example of a method for manufacturing a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. <FIG> is a schematic diagram of a method for manufacturing a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. (a) in <FIG> is a schematic diagram in which the electronic element <NUM> is on a substrate <NUM> and is not processed, (b) in <FIG> is a schematic diagram in which a periphery of the electronic element <NUM> is covered with a heat dissipation cover <NUM> and a phase-change thermally conductive material <NUM> is placed in an accommodation cavity <NUM>, (c) in <FIG> is a schematic diagram in which a heat dissipation module <NUM> is attached to the heat dissipation cover <NUM>, and (d) in <FIG> is a schematic diagram in which the phase-change thermally conductive material <NUM> is melted when the electronic element <NUM> is in a working state.

As shown in <FIG> and <FIG>, in an embodiment provided in this application, the manufacturing method includes the following steps.

Step <NUM>: In the environment that meets the preset temperature condition, after a phase-change thermally conductive material <NUM> is constructed into a sheet-like structure, stick the sheet-like structure to an inner surface of a top wall of a heat dissipation cover <NUM>, to form an integrated structure.

Step <NUM>: Cover a periphery of the electronic element <NUM> with the integrated structure formed by the phase-change thermally conductive material <NUM> and the heat dissipation cover <NUM>, and fixedly connect the integrated structure to the substrate <NUM>, so that the phase-change thermally conductive material <NUM> is placed in an accommodation cavity <NUM> surrounded by the substrate <NUM> and the heat dissipation cover <NUM>.

Step <NUM>: Attach a heat dissipation module <NUM> to the top wall, and enable a protruding thermally conductive column <NUM> on an outer wall of the heat dissipation module <NUM> to sequentially pass through an opening <NUM> of the heat dissipation cover <NUM> and an avoidance hole <NUM> of the phase-change thermally conductive material <NUM> and extend into the accommodation cavity <NUM>.

In this embodiment, the phase-change thermally conductive material <NUM> and the heat dissipation cover <NUM> form the integrated structure. When the electronic element <NUM> is covered, the phase-change thermally conductive material <NUM> does not need to be placed separately, so that an operation such as positioning or adjustment required when the phase-change thermally conductive material <NUM> is placed in the accommodation cavity <NUM> is avoided, thereby further reducing process control difficulty and improving production efficiency.

In this embodiment, the heat dissipation module <NUM> is directly in contact with the phase-change thermally conductive material <NUM> by using the thermally conductive column <NUM>, so that a spacing between the electronic element <NUM> and the heat dissipation module <NUM> can be smaller. This reduces a length of a heat transfer path, reduces heat transfer resistance, and facilitates an ultra-thin design of the electronic device.

In addition, the thermally conductive column <NUM> added to the heat dissipation module <NUM> passes through the avoidance hole <NUM> of the phase-change thermally conductive material <NUM> and extends into the accommodation cavity <NUM>, and after the phase-change thermally conductive material <NUM> is melted, the phase-change thermally conductive material <NUM> in a liquid state may be fully wrapped on a bottom wall and a peripheral wall of the thermally conductive column <NUM>, so that the heat dissipation module <NUM> and the phase-change thermally conductive material <NUM> have a relatively large contact area for heat exchange, thereby improving heat transfer efficiency.

Optionally, a manner of constructing the phase-change thermally conductive material <NUM> into the sheet-like structure may be mechanical pressing, pouring after heating and melting, or the like. The phase-change thermally conductive material <NUM> made into the sheet-like structure may be sticked to the inner surface of the top wall of the heat dissipation cover <NUM> by using a hot melt adhesive or another adhesive, so that the phase-change thermally conductive material <NUM> and the heat dissipation cover <NUM> form an integrated structure, thereby reducing control difficulty in an assembling process.

Optionally, a production manner of the heat dissipation cover <NUM> may be metal stamping.

When stamping is performed on the heat dissipation cover <NUM> and the phase-change thermally conductive material <NUM> is constructed into a sheet, the opening <NUM> further needs to be disposed on the heat dissipation cover <NUM>, and the avoidance hole <NUM> needs to be disposed on the sheet-like phase-change thermally conductive material <NUM>. Then, the phase-change thermally conductive material <NUM> is sticked to the heat dissipation cover <NUM>, and the opening <NUM> and the avoidance hole <NUM> should be directly opposite each other after sticking, for the thermally conductive column <NUM> on the heat dissipation module <NUM> to pass through in a subsequent step.

Optionally, after the heat dissipation cover <NUM> and the phase-change thermally conductive material <NUM> are sticked into an integrated structure, a hole may be disposed on the integrated structure, to synchronously form the opening <NUM> and the avoidance hole <NUM> that are disposed directly opposite each other.

The method for manufacturing a heat dissipation structure of an electronic element <NUM> in this embodiment of this application needs to be performed in the environment that meets the preset temperature condition, so that the phase-change thermally conductive material <NUM> always keeps a solid state in a manufacturing phase of the heat dissipation structure. The preset temperature condition is <NUM>~<NUM>, that is, normal temperature ± <NUM>.

An average annual indoor temperature in most regions can meet the preset temperature condition. Therefore, no air adjustment is required to meet a production condition, production costs can be reduced, and the manufacturing method can be widely used.

In an embodiment, a melting point of the phase-change thermally conductive material <NUM> is <NUM>~<NUM>.

A melting point range is higher than a normal temperature, so that the phase-change thermally conductive material <NUM> can be kept in a solid state indoor, and the phase-change thermally conductive material <NUM> can be directly picked up manually or by using a mechanical hand to perform a filling operation. In this way, a filling process can be completely free of dependence on a glue dispensing station.

The phase-change thermally conductive material <NUM> (Phase Change Material, PCM) refers to a substance whose state can be changed when a temperature is unchanged and that can provide latent heat. A process of changing a physical property is referred to as a phase change process. In this case, a large amount of latent heat is absorbed or released by the phase-change material. The phase-change material can absorb or release heat when a phase change occurs, but a temperature of the material does not change or changes slightly. Usually, the phase-change material begins to soften and flow at a temperature of <NUM>~<NUM>, and is in a solid state at a normal temperature. The phase-change material can be separately used without a reinforcing material. This avoids impact of the reinforcing material on heat conduction performance. Therefore, the phase-change material can freely adjust an internal temperature of a product within a specific temperature range if the external temperature changes. That is, when the external ambient temperature rises, heat can be stored to ensure that an increase in the temperature of the product is small. When the external temperature drops, energy can be released to ensure that a decrease in the temperature of the product is small.

Optionally, the foregoing phase-change thermally conductive material <NUM> may be an organic phase-change material (organic phase-change materials, OPCMs), an inorganic phase-change material (inorganic phase-change materials, IPCMs), or a composite phase-change material (Composite phase-change materials, CPCMs).

Specifically, in this application, paraffin or fatty acid may be used as the organic phase-change material. Generally, a phase change temperature of a homologous organic substance increases with a carbon chain of the homologous organic substance, so that a series of phase-change materials can be obtained. For example, paraffin is a mixture of solid-state advanced alkane, and a molecular formula of a main component is CnH2n+<NUM>, where n=<NUM>~<NUM>. The main component is straight-chain alkane, and there is a little branched alkane and monocyclic alkane with long side chains. A melting point range of the paraffin is <NUM>~<NUM>, that is, some paraffin with long carbon chains is selected to meet the melting point range of the phase-change material required in this application.

Specifically, a composite phase-change material that can be selected in this application includes a paraffin/graphene composite phase-change material. Organic paraffin is used as a phase-change material, and expanded graphite is used as a support structure, to form the composite phase-change material. A melting point range of the composite phase-change material is <NUM>~<NUM>, which can meet a condition that a melting point is <NUM>~<NUM> in this application.

Specifically, an inorganic phase-change material that can be selected in this application includes crystalline hydrated salt, molten salt, a metal material, or another inorganic substance.

In an embodiment, considering that thermal resistance of a metal material is low and a thermal conductivity is large, the phase-change thermally conductive material <NUM> selected in this embodiment of this application is a metal material.

Optionally, the metal material may be a gallium-based alloy, an indium-based alloy, or a bismuth-based alloy.

The foregoing metal material mainly includes metal such as bismuth, indium, tin, and gallium. Addition proportions of different metal are adjusted to obtain metal alloys with different melting points, which may be used as the phase-change thermally conductive material <NUM> in this application. In metal alloys obtained by adding different metal, a metal alloy whose melting point range is <NUM>~<NUM> needs to be selected.

In this application, the gallium-indium alloy is preferably used as the phase-change thermally conductive material <NUM>. Thermally conductive performance of the gallium-indium alloy is more than <NUM> times that of a conventional thermally conductive paste. In addition, the gallium-indium alloy has advantages such as non-volatility, a long service life, stable physical and chemical properties, reliable use, and non-toxic.

It should be noted that, in this application, a metal material in a solid state at a normal temperature is used as the phase-change thermally conductive material <NUM>, and a heat conductivity of the metal material can reach <NUM>~<NUM> W/(m*K). However, a use temperature needs to be greater than a phase-change temperature (that is, a melting point temperature) of the metal material. An optimal heat conduction effect can be achieved only when it is ensured that the metal material is in a liquid state. If the use temperature cannot reach the phase-change temperature, that is, the metal material is still in a solid state, a gap between the electronic element <NUM> and the heat dissipation cover <NUM> or between the electronic element <NUM> and the heat dissipation module <NUM> cannot be filled, and there is a large amount of air. In this case, heat generated by the electronic element <NUM> cannot be transmitted to the heat dissipation cover <NUM> or the heat dissipation module <NUM> by using the metal material. Therefore, a heat conduction effect is extremely poor.

In an embodiment, the heat dissipation cover <NUM> is a metal cover.

Considering a heat conduction effect and a shielding effect of the heat dissipation cover <NUM>, the heat dissipation cover <NUM> is a metal cover, such as stainless steel, a copper-nickel-zinc alloy, or a magnesium-aluminum alloy. This is not limited in this application.

In addition, when the heat dissipation cover <NUM> is the metal cover, pick-up and transfer may be performed by using a magnetic mechanical arm. This facilitates an operation in an assembly step.

As shown in (c) in <FIG>, in an embodiment, the heat dissipation module <NUM> has a heat dissipation fin or heat dissipation grille <NUM>.

The heat dissipation module <NUM> with the heat dissipation fin or heat dissipation grille <NUM> can increase a heat exchange area with the air, and improve heat dissipation efficiency.

According to a second aspect, an embodiment of this application further provides a heat dissipation structure of an electronic element <NUM>. <FIG> is an assembly diagram of a heat dissipation structure of the electronic element <NUM> according to an embodiment of this application. <FIG> is an exploded view of <FIG>. <FIG> is a schematic diagram of another angle of view of <FIG>.

As shown in <FIG>, the heat dissipation structure includes a substrate <NUM>, a heat dissipation cover <NUM>, and a phase-change thermally conductive material <NUM>.

The substrate <NUM> is provided with the electronic element <NUM>.

The heat dissipation cover <NUM> is connected to the substrate <NUM> and surrounds the electronic element <NUM>, and the heat dissipation cover <NUM> and the substrate <NUM> form an accommodation cavity <NUM> that accommodates the electronic element <NUM>.

The phase-change thermally conductive material <NUM> is disposed in the accommodation cavity <NUM>, and a melting point of the phase-change thermally conductive material <NUM> is <NUM>~<NUM>, which is higher than a normal temperature of <NUM>. Therefore, the phase-change thermally conductive material <NUM> is in a solid state at the normal temperature.

In the heat dissipation structure of the electronic element <NUM> provided in this embodiment of this application, the phase-change thermally conductive material <NUM> whose melting point is <NUM>~<NUM> is selected. A melting point temperature of the phase-change thermally conductive material <NUM> is higher than <NUM> that is a normal temperature. Therefore, the phase-change thermally conductive material <NUM> is in a solid state at the normal temperature, and can be directly picked up manually or by using a mechanical hand to perform a filling operation, so that a filling process can be free of dependence on a glue dispensing station. In this way, steps and devices in the filling process are simplified, and production and manufacturing costs of the heat dissipation structure are reduced.

A specific type of the electronic element <NUM> is not limited in this application. For example, the electronic element <NUM> may be a central processing unit (central processing unit, CPU), a graphics processing unit (graphics processing unit, GPU), a universal flash storage (universal flash storage, UFS), a system in package (System in Package, SiP) element, an antenna in package (antenna in package, AiP) element, a system on a chip (system on a chip, SOC) element, a double data rate (double data rate, DDR) memory, a radio frequency integrated circuit (radio frequency integrated circuit, RF IC), a radio frequency power amplifier (radio frequency power amplifier, RF PA), a power management unit (power management unit, PMU), an embedded multimedia card (embedded multimedia card, EMMC), or the like.

A specific type of the substrate <NUM> is not limited in this application. For example, the substrate <NUM> may be a printed circuit board (printed circuit board, PCB), a flexible printed circuit (Flexible Printed Circuit, FPC), a double-sided PCB board, a multi-layer PCB board, or the like.

Optionally, to prevent the phase-change thermally conductive material <NUM> from seeping into a contact surface substrate in contact with the phase-change thermally conductive material <NUM>, anti-seepage glue is applied to an inner surface of a peripheral wall and an inner surface of a top wall that are of the heat dissipation cover <NUM> and an upper surface of the electronic element <NUM>, that is, positions in contact with the phase-change thermally conductive material <NUM>.

A size of the accommodation cavity <NUM> formed between the heat dissipation cover <NUM> and the substrate <NUM> may be determined according to a size of the substrate <NUM>. For example, when a large accommodation cavity <NUM> is needed, a substrate <NUM> with a large size may be disposed. Alternatively, a size of the accommodation cavity <NUM> may be determined according to power consumption of the electronic element <NUM>. When power consumption of the electronic element <NUM> is relatively high, a large amount of heat is generated. In this case, the accommodation cavity <NUM> may be relatively large, to accommodate more phase-change thermally conductive materials <NUM> and improve a heat transfer rate. When power consumption of the electronic element <NUM> is relatively low, an amount of heat generated by the electronic element <NUM> is relatively small. In this case, a small accommodation cavity <NUM> can also achieve a purpose of heat conduction. In this case, a filling amount of the phase-change thermally conductive material <NUM> may be reduced, and manufacturing costs of the heat dissipation structure are further reduced.

In addition, for the electronic device, the electronic element <NUM> may be disposed on the substrate <NUM>. The substrate <NUM> on which the electronic element <NUM> is disposed may be disposed in the electronic device. The size of the substrate <NUM> may be determined according to a size of the electronic device and a heat dissipation performance requirement.

<FIG> is a cross-sectional view of another example of a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. (a) in <FIG> is a schematic diagram before the electronic element <NUM> works, and (b) in <FIG> is a schematic diagram in which the phase-change thermally conductive material <NUM> is melted after the electronic element <NUM> works. As shown in <FIG>, optionally, the phase-change thermally conductive material <NUM> and the heat dissipation cover <NUM> may be separate structures that are not connected. Before the heat dissipation cover <NUM> is fixedly connected to the substrate <NUM>, the phase-change thermally conductive material <NUM> is placed in the accommodation cavity <NUM>.

As shown in <FIG>, in an embodiment, the heat dissipation structure further includes a heat dissipation module <NUM> attached to a top wall of the heat dissipation cover <NUM>.

The heat dissipation module <NUM> is added in this embodiment. Compared with a separate heat dissipation cover <NUM>, the added heat dissipation module <NUM> can provide more diversified technical solutions for fast heat dissipation. For example, a heat dissipation module <NUM> including a heat dissipation fin or a heat dissipation grille <NUM> can provide a larger heat exchange area than the heat dissipation cover <NUM>. The heat dissipation module <NUM> may further be a metal support of a functional element in the electronic device. For example, when the electronic device is a mobile phone, the heat dissipation module <NUM> is a metal support part of a battery or a screen, and heat can be rapidly exported from the inside of the mobile phone to the outside and emitted to the environment.

Optionally, a manner of attaching the heat dissipation module <NUM> and the heat dissipation cover <NUM> is as follows: A bottom area of the heat dissipation module <NUM> is set to be greater than an area of the top wall of the heat dissipation cover <NUM>, a periphery of the heat dissipation module <NUM> is bolted to the substrate <NUM>, and a middle part of the heat dissipation module <NUM> is pressed onto the heat dissipation cover <NUM>. Alternatively, the heat dissipation module <NUM> is directly attached to the heat dissipation cover <NUM> in a manner such as sticking, welding, or bolting.

<FIG> is a cross-sectional view of a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. As shown in <FIG>, the heat dissipation cover <NUM> may be in a ring shape, and surrounds the electronic element <NUM> in a structure similar to a dam, the top of the heat dissipation cover <NUM> is open, and the heat dissipation module <NUM> covers the opening of the heat dissipation cover <NUM>. The heat dissipation module <NUM> may be in contact with the melted phase-change thermally conductive material <NUM> through the opening, so that the phase-change thermally conductive material <NUM> conducts heat generated by the electronic element <NUM> to the heat dissipation module <NUM>.

As shown in <FIG>, in an embodiment, an opening <NUM> is disposed on the top wall, a thermally conductive column <NUM> protrudes from an outer wall of the heat dissipation module <NUM>, and the thermally conductive column <NUM> passes through the opening <NUM> and extends into the accommodation cavity <NUM>.

In this embodiment, the thermally conductive column <NUM> passes through the opening <NUM>, extends into the accommodation cavity <NUM>, and is in contact with the melted phase-change thermally conductive material <NUM>, to perform heat conduction. After the phase-change thermally conductive material <NUM> is melted, the phase-change thermally conductive material <NUM> in a liquid state may be fully wrapped on a bottom wall and a peripheral wall of the thermally conductive column <NUM>, so that the heat dissipation module <NUM> and the phase-change thermally conductive material <NUM> have a relatively large contact area for heat exchange, thereby improving heat transfer efficiency. The heat dissipation module <NUM> is directly in contact with the phase-change thermally conductive material <NUM> by using the thermally conductive column <NUM>, so that a spacing between the electronic element <NUM> and the heat dissipation module <NUM> can be smaller. This reduces a length of a heat transfer path, reduces heat transfer resistance, and facilitates an ultra-thin design of the electronic device.

Optionally, sealing may be performed at an insertion position between the thermally conductive column <NUM> and the opening <NUM>, or sealing may not be performed. This may be selected according to different application scenarios. For example, in a static use scenario in which the electronic device is a desktop computer, a game console, a television, or the like, a possibility of flowing of the melted phase-change thermally conductive material <NUM> due to vibration is relatively low. Therefore, sealing may not be performed between the thermally conductive column <NUM> and the opening <NUM>, thereby reducing manufacturing costs. In a dynamic use scenario in which the electronic device is a notebook computer, a portable game console, a mobile phone, a wearable device, or the like, the melted phase-change thermally conductive material <NUM> is prone to flow out from the insertion position between the thermally conductive column <NUM> and the opening <NUM> due to vibration. Therefore, sealing needs to be performed to prevent leakage.

<FIG> is a cross-sectional view of another example of a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. (a) in <FIG> is a schematic diagram before the electronic element <NUM> works, and (b) in <FIG> is a schematic diagram in which the phase-change thermally conductive material <NUM> is melted after the electronic element <NUM> works. As shown in <FIG>, optionally, only one thermally conductive column <NUM> may be disposed, that is, a large round-table structure. In this case, a corresponding opening <NUM> is a large round hole, and the round table passes through the round hole and extends into the accommodation cavity <NUM>, and is in contact with the melted phase-change thermally conductive material <NUM>. However, this structure is not conducive to improving a contact area between the heat dissipation module <NUM> and the phase-change thermally conductive material <NUM>, and the large round-table structure increases an overall weight and manufacturing costs of the heat dissipation module <NUM>.

Therefore, to resolve the foregoing problem, as shown in <FIG>, in an embodiment, there are a plurality of thermally conductive columns <NUM> spaced from each other, and the plurality of thermally conductive columns <NUM> pass through a plurality of openings <NUM> in a one-to-one correspondence and extend into the accommodation cavity <NUM>.

In this embodiment, after the phase-change thermally conductive material <NUM> is melted, the phase-change thermally conductive material <NUM> in a liquid state may be fully wrapped on bottom walls and peripheral walls of the plurality of thermally conductive columns <NUM>, so that the heat dissipation module <NUM> and the phase-change thermally conductive material <NUM> have a relatively large contact area, and an overall weight and manufacturing costs of the heat dissipation module <NUM> are reduced.

In an embodiment, the phase-change thermally conductive material <NUM> is a metal material.

In an embodiment, the phase-change thermally conductive material <NUM> includes a gallium-based alloy, an indium-based alloy, or a bismuth-based alloy.

In this embodiment, selection of the phase-change thermally conductive material <NUM> may be the same as or similar to selection of the phase-change thermally conductive material <NUM> in the foregoing manufacturing method embodiment.

In an embodiment, the heat dissipation cover <NUM> is a metal cover. The metal may be, for example, a copper-nickel-zinc alloy, an aluminum alloy, or a magnesium alloy.

In addition to preventing leakage of the phase-change thermally conductive material <NUM> and having a heat dissipation function, in this embodiment, the heat dissipation cover <NUM> may further support a weight of the heat dissipation module <NUM>, to avoid damage caused by the heat dissipation module <NUM> to the electronic element <NUM> on the substrate <NUM>, thereby protecting the electronic element <NUM>. In addition, a closed accommodation cavity <NUM> is formed by using the heat dissipation cover <NUM>, the substrate <NUM>, and the heat dissipation module <NUM>, and the electronic element <NUM> is disposed on the substrate <NUM>. The electronic element <NUM> can be prevented from being exposed to the air, thereby protecting the electronic element <NUM>. In addition, the phase-change thermally conductive material <NUM> placed in the accommodation cavity <NUM> is prevented from leaking or reacting with external air or another substance, to avoid affecting normal operation of the electronic device.

Optionally, a shape of the heat dissipation cover <NUM> is a cube, a circle, or the like. This is not limited in this application.

As shown in <FIG>, in an embodiment, the heat dissipation module <NUM> has a heat dissipation fin or heat dissipation grille <NUM>.

In this embodiment, the heat dissipation module <NUM> includes the heat dissipation fin or heat dissipation grille <NUM>, so that a contact area for heat exchange with the air can be increased.

Optionally, a fan may be added outside of the heat dissipation module <NUM>. An air flow direction of the fan is right against the heat dissipation fin or heat dissipation grille <NUM>, and heat from the electronic element <NUM> is quickly removed from the heat dissipation module <NUM> in an air cooling manner.

Optionally, a water cooling mechanism may be further added inside the heat dissipation module <NUM>, to further improve a heat dissipation effect. For example, a circulating pump is added. The heat dissipation module <NUM> is a hollow structure, an inlet and an outlet are disposed on the heat dissipation module <NUM>, and the circulating pump is connected to the inlet and the outlet by using a pipeline, to inject circulating cooling water into the heat dissipation module <NUM>.

Specifically, the cooling water is closed and circulated in the pipeline, and heat of the heat dissipation module <NUM> is taken away by the cooling water, and then is emitted to the environment by using the pipeline. Alternatively, the pipeline is connected to an external heat exchanger, heat of the heat dissipation module <NUM> is taken away by the cooling water and flows into the heat exchanger, and the heat exchanger emits the heat through the air.

Optionally, the heat dissipation module <NUM> may be metal or non-metal.

Specifically, the heat dissipation module <NUM> may be connected to a metal support of some functional elements in the electronic device, for example, a metal support part of a battery or a screen, and may conduct heat to the metal support part, and then the metal support part emits the heat to the environment.

Specifically, the heat dissipation module <NUM> may alternatively be a metal middle frame of the electronic device.

Specifically, some non-metal materials may also have a large thermal conductivity, and have a relatively strong heat conduction capability. For example, the heat dissipation module <NUM> may alternatively be a non-metal structural component, which is specifically a non-metal structural component made of a graphene material.

<FIG> is a cross-sectional view of another example of a heat dissipation structure of an electronic element <NUM> according to an embodiment of this application. (a) in <FIG> is a schematic diagram before the electronic element <NUM> works, and (b) in <FIG> is a schematic diagram in which the phase-change thermally conductive material <NUM> is melted after the electronic element <NUM> works.

As shown in <FIG>, in an embodiment, a plurality of electronic elements <NUM> are disposed on the substrate <NUM>, and the heat dissipation cover <NUM> surrounds the plurality of electronic elements <NUM>.

In this embodiment, a single heat dissipation cover <NUM> may be correspondingly mounted on the outside of the plurality of electronic elements <NUM>, to perform a protection function, a heat dissipation function, and a signal interference prevention function on the plurality of electronic elements <NUM>. A single heat dissipation cover <NUM> is corresponding to a plurality of electronic elements <NUM>, so that costs of a production process and a mounting process of the heat dissipation cover <NUM> can be reduced, thereby reducing manufacturing costs of the heat dissipation structure in this application.

Theoretically, a temperature range of a melting point of the phase-change thermally conductive material <NUM> in this application is relatively large, and may be selected within a temperature range of <NUM>~<NUM>. However, during actual production and application, it is found that the melting point of the phase-change thermally conductive material <NUM> should not be too low or too high. A specific reason is as follows: If the melting point is too low, the phase-change thermally conductive material <NUM> is easy to liquefy and inconvenient to assemble. Therefore, strict temperature control is needed for an assembly environment, and this increases production and manufacturing costs. If the melting point is too high, the phase-change thermally conductive material <NUM> cannot liquefy easily, and this affects heat conduction. If the electronic element <NUM> works at a temperature close to the melting point for a long time, functional damage of the electronic element is caused, and a service life of the electronic element is reduced. In conclusion, in this embodiment, a melting point of the phase-change thermally conductive material <NUM> is <NUM>~<NUM>.

According to a third aspect, this application further provides an electronic device. <FIG> is a schematic diagram of an electronic device according to an embodiment of this application. As shown in <FIG>, the electronic device <NUM> is a notebook computer, and a heat dissipation structure <NUM> is disposed inside a body.

In addition, the electronic device <NUM> may alternatively be any one of a desktop computer, a tablet computer, a game console, a mobile phone, an electronic watch, a router, a set-top box, a television, and a modem.

Optionally, in the electronic device <NUM> in this application, in addition to applying the foregoing heat dissipation structure <NUM>, a position relationship of the heat dissipation structure <NUM> in the electronic device <NUM> may be properly arranged, to further improve a heat dissipation effect of the electronic device <NUM> and improve heat conduction efficiency of the heat dissipation structure <NUM>. A specific layout design is as follows:.

Claim 1:
A method for manufacturing a heat dissipation structure of an electronic element (<NUM>), comprising:
placing a substrate (<NUM>) having an electronic element (<NUM>) in an environment that meets a preset temperature condition (<NUM>); and
in the environment that meets the preset temperature condition, covering a periphery of the electronic element (<NUM>) with a heat dissipation cover (<NUM>), fixedly connecting the heat dissipation cover (<NUM>) to the substrate (<NUM>), and placing a solid-state phase-change thermally conductive material (<NUM>) in an accommodation cavity (<NUM>) surrounded by the substrate (<NUM>) and the heat dissipation cover (<NUM>);
the covering a periphery of the electronic element (<NUM>) with a heat dissipation cover (<NUM>), fixedly connecting the heat dissipation cover (<NUM>) to the substrate (<NUM>), and placing a solid-state phase-change thermally conductive material (<NUM>) in an accommodation cavity (<NUM>) surrounded by the substrate (<NUM>) and the heat dissipation cover (<NUM>) comprises:
after the phase-change thermally conductive material (<NUM>) is constructed into a sheet-like structure, sticking the sheet-like structure to an inner surface of a top wall of the heat dissipation cover (<NUM>), to form an integrated structure (<NUM>); and
covering the periphery of the electronic element (<NUM>) with the integrated structure, and fixedly connecting the integrated structure to the substrate (<NUM>) (<NUM>),
wherein an opening (<NUM>) is disposed on the top wall, an avoidance hole (<NUM>) is disposed on the sheet-like structure, and the manufacturing method further comprises:
attaching a heat dissipation module (<NUM>) to the top wall, and enabling a protruding thermally conductive column (<NUM>) on an outer wall of the heat dissipation module (<NUM>) to sequentially pass through the opening (<NUM>) and the avoidance hole (<NUM>) and extend into the accommodation cavity (<NUM>) (<NUM>).