CN110167324A - Shell assembly, preparation method thereof and electronic equipment - Google Patents

Abstract

The embodiment of the application provides a shell assembly, a preparation method of the shell assembly and electronic equipment, wherein the shell assembly comprises a middle frame and a graphite layer, the middle frame comprises a middle plate and a frame, the frame is surrounded on the middle plate and connected to the middle plate, the graphite layer is formed by coating graphite powder on the surface of the middle plate, and the graphite powder is prepared in the following mode: sintering the PI film at high temperature to graphitize the PI film, and crushing the PI film to obtain graphite powder. The embodiment of the application provides a shell assembly and a preparation method thereof and electronic equipment, because graphite layer direct coating is on the surface of medium plate, and owing to directly coating through graphite powder and forming, it need not use the binder, consequently the thermal conductivity in thickness direction is showing and is improving, therefore makes graphite layer not only can carry out better soaking in the plane direction, can also utilize its thermal conductivity in thickness direction directly outwards to give off the heat simultaneously, and then reduces electronic equipment's the phenomenon of generating heat.

Description

Housing assembly, method of making the same, and electronic device

technical field

The present application relates to the technical field of heat dissipation of electronic equipment, and in particular, to a casing assembly and a preparation method thereof, and electronic equipment.

Background technique

The power supply of electronic equipment or other electronic devices will generate a lot of heat during operation, which will increase the overall temperature of the electronic equipment. When the temperature rises sharply, there is a risk of spontaneous combustion. Some current electronic devices will automatically take some measures to reduce power consumption when the temperature rises, which leads to a decrease in the operating efficiency of the electronic device, resulting in the electronic device becoming stuck; at the same time, the user may feel hot when holding the electronic device.

In the prior art, some devices conduct heat conduction by pasting graphite sheets in electronic equipment, but the graphite sheets have good heat conduction effect on the plane, but the heat conduction effect in the thickness direction is not good, and cannot effectively solve the problem of electronic equipment. Device heating problem.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a housing assembly, a method for manufacturing the same, and an electronic device, which can improve the heat dissipation effect of the electronic device.

In a first aspect, an embodiment of the present application provides a method for manufacturing a housing assembly, including: providing a middle frame, the middle frame including a middle plate and a frame, the frame surrounding the middle plate and connected to the middle frame A middle plate; the surface of the middle plate is coated with graphite powder with a predetermined thickness, and the graphite powder is prepared by the following methods: sintering a PI film at a high temperature to make it graphitized, and pulverizing to obtain the graphite powder.

In a second aspect, an embodiment of the present application provides a housing assembly, including a middle frame and a graphite layer, the middle frame includes a middle plate and a frame, and the frame is surrounded by and connected to the middle plate , the graphite layer is formed by coating the surface of the middle plate with graphite powder, and the graphite powder is prepared by the following method: sintering the PI film at a high temperature to make it graphitized, and pulverizing the graphite powder.

In a third aspect, an embodiment of the present application provides an electronic device, including the above-mentioned housing assembly and a heating element, wherein the heating element is provided on the middle plate and is thermally connected to the graphite layer.

In the case assembly, the preparation method thereof, and the electronic device provided in the embodiments of the present application, since the graphite layer is directly coated on the surface of the middle plate, and since it is formed by direct coating with graphite powder, it does not need to use an adhesive. The thermal conductivity in the thickness direction is significantly improved, so that the graphite layer can not only perform better heat distribution in the plane direction, but also directly dissipate heat by using its thermal conductivity in the thickness direction, thereby reducing the heat generation of electronic equipment. Phenomenon.

These and other aspects of the present application will be more clearly understood in the description of the following embodiments.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a housing assembly provided by an embodiment of the present application;

2 is a schematic cross-sectional structural diagram of a middle frame in a housing assembly provided by an embodiment of the present application;

Fig. 3 is the enlarged view of III in Fig. 2;

4 is a schematic structural diagram of another middle plate provided by an embodiment of the present application;

FIG. 5 is a schematic partial structure diagram of another housing assembly provided by an embodiment of the present application;

6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

FIG. 7 is a cross-sectional structural view taken along line AA in FIG. 6 .

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

With the rapid development of electronic devices (eg, mobile terminals), the power consumption of the electronic devices also increases gradually, and accordingly, the heat generated by the electronic devices during the working process is also relatively large. Taking the power supply as an example, the existing graphite heat sink is fixed on the heating element by means of adhesive to dissipate heat.

Graphite sheet is a brand-new thermal conduction and heat dissipation material, with unique grain orientation, uniform heat conduction along two directions (X and Y directions) on the plane, the sheet-like structure can be well adapted to any surface, shielding heat sources and components while improving the performance of consumer electronics. The thermal conductivity in two directions on the plane can reach the range of 150-1500W/m-K. However, the thermal conductivity of the graphite sheet in the thickness direction (Z direction) is usually not good, especially when it is applied to electronic equipment, it needs to be pasted on the middle frame by adhesive in the thickness direction, and because the graphite sheet itself is thin, usually After multiple graphite sheets are bonded to each other, they are applied as a whole, and the adhesive has a large thermal resistance. The use of the adhesive further reduces the Z thermal conductivity of the graphite sheet for heat dissipation. For example, the graphite sheet is attached to the power supply and the heating chip in the electronic equipment, and the heating area and the non-heating area are conducted through the graphite sheet to prevent local overheating. However, this part of the heat cannot be conducted along the thickness direction and is dissipated through the shell.

Therefore, the inventor proposes the heat sink and the manufacturing method thereof, the housing assembly and the electronic device in the embodiments of the present application. The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , the present embodiment provides a housing assembly 100 including a middle frame 30 and a graphite layer 20 , wherein the middle frame 30 includes a frame 31 and a middle plate 32 , the frame 31 is disposed along the edge of the middle plate 32 and The middle plate 32 is connected, wherein the graphite layer 20 is disposed on the surface of the middle plate 32 .

Referring to FIG. 2 , the middle plate 32 includes a first surface 321 and a second surface 322 that are away from each other, wherein the first surface 321 and the second surface 322 can be used to selectively set various types of components, for example, the components can be of various types heating elements, such as heating chips, power supplies, display screens, etc.

Referring again to FIG. 1 , in some embodiments, the housing assembly 100 may further include an optional front cover 40 and a rear cover 45 , wherein the front cover 40 is assembled on the frame 31 of the middle frame 30 and is located on the side of the first surface 321 , the rear cover 45 is assembled on the frame 31 of the middle frame 30 and located on the side of the second surface 322 . In some embodiments, the first surface 321 can be used for setting a display screen, wherein the display screen can be an LCD screen, an LED screen, an OLED screen, etc., or a flexible screen or a non-flexible screen. The second surface 322 is used for arranging various types of components.

Please refer to FIG. 2 and FIG. 3 together. Specifically, the graphite layer 20 is roughly planar, and its thickness can be 0.017mm-5mm. Graphite crystals mostly exhibit a hexagonal planar network structure. In this application, the graphite layer 20 is formed on the first surface 321 and/or the second surface 322 of the middle plate 32 by coating with graphite powder.

In this embodiment, the graphite layer 20 is only disposed on the first surface 321 , that is, the graphite layer 20 is disposed on the surface of the middle plate 32 facing the front case 40 . It can be understood that, since the first surface 321 is mainly used for setting the display screen, there is a certain gap between the display screen and the middle frame 30, and the graphite layer 20 is disposed on the first surface 321, which will not increase the thickness of the electronic device. . At the same time, one side of the display screen is usually a non-heating area of the electronic device, and the graphite layer 20 guides heat to this area, which can reduce the temperature of the heating element quickly and achieve a better heat-spreading effect. It should be understood that it is also feasible that the graphite layer 20 is disposed on the second surface 322 , and in this case, the heating element can be directly disposed on the surface of the graphite layer 20 . Alternatively, they can be disposed on the first surface 321 and the second surface 322 at the same time.

The graphite powder is prepared by the following method: sintering the PI film at high temperature to make it graphitized, and pulverizing to obtain the graphite powder. Polyimide film (PI film) includes two types: homophenyl type polyimide film and biphenyl type polyimide film. The film preparation method is: polyamic acid solution casting film, stretching, high temperature imidization. The film is yellow and transparent, with a relative density of 1.39 to 1.45. It has outstanding high temperature resistance, radiation resistance, chemical corrosion resistance and electrical insulation properties, and can be used for a long time in the air at 250 to 280 °C.

The PI film is graphitized by sintering at high temperature. For example, the treatment is carried out in the following way: after biaxially stretching the PI film, in a carbonization furnace under an argon atmosphere, the temperature is gradually increased from 400 ° C to 800 ° C for heat treatment. 3h; then the carbonized samples were graphitized in a hot press furnace at a high temperature from 2500°C to 2800°C.

The graphitized PI film is directly pulverized to obtain graphite powder, wherein the graphitized PI film does not need to be rolled and other operations, but is directly obtained by mechanical pulverization or grinding pulverization. The graphite powder prepared in this way has been subjected to high temperature sintering and graphitization treatment, so the atomic arrangement of the obtained graphite powder is also graphitized, and its particle size is less than 0.01mm, which has good thermal conductivity of graphite.

The graphite powder is formed on the surface of the middle plate 32 by coating, thus avoiding the use of glue between the graphite and the middle plate 32, and the graphite and the middle plate 32 can be directly connected, reducing the thermal resistance caused by the use of glue . At the same time, since no adhesive is required, the graphite layer 20 does not increase the thickness of the housing assembly 100, or the graphite layer 20 can be thicker in the same thickness space, which is conducive to heat conduction.

There are many ways of coating, such as: spraying and printing. Among them, spraying can be carried out in the following ways: N ₂ is used for both the working gas and the powder feeding gas, the working gas pressure is 2.0MPa-3.0MPa, and the working gas temperature is 300 ℃～500℃, the spraying distance is 10mm～30mm, and the walking speed of the spray gun is 100mm/s～400mm/s.

Printing can be carried out in the following manner: mixing graphite powder in a solvent, printing directly on the surface of the middle plate 32, and drying the solvent. In other embodiments, the graphite layer 20 may also be formed by roll coating or the like.

The thickness of the graphite layer 20 can be adjusted according to specific design requirements, for example, it can be set to 0.3-4 mm, which is especially beneficial for preparing the graphite layer 20 with a larger thickness of 2.2-4 mm. Since the graphite layer 20 is all made of graphite powder in the thickness direction, and no adhesive exists, the thermal resistance is small, and the thermal conduction effect in the thickness direction is better.

Compared with the traditional method of directly pasting the sintered and calendered graphite sheet on the middle plate 32, the above-mentioned shell assembly 100 does not require a calendering operation, which saves the production process. At the same time, the thickness of the graphite layer 20 is thicker than that of a single graphite sheet (for example, it can reach 2.2-4 mm), and no adhesive is required, which reduces the thermal resistance in the thickness direction.

Referring to FIG. 4 , in some embodiments, grooves 323 are provided on the first surface 321 or the second surface 322 of the middle plate 32 , and the depth of the grooves 323 may be less than or equal to the preset thickness of the graphite layer 20 . When the graphite layer 20 is disposed in the groove 323, the space occupied by the graphite layer 20 in the thickness direction of the casing assembly 100 can be further reduced, which is beneficial to make the electronic device smaller and thinner.

When the depth of the groove 323 is equal to the thickness of the graphite layer 20, the surface of the graphite layer 20 can be flush with the first surface 321 or the second surface 322, so that it is more convenient to arrange various types of components without Steps may be formed between the graphite layer 20 and the surface of the middle plate 32 .

In the process of coating the graphite powder, since the adhesive force between the surface of the middle plate 32 and the graphite powder is small, to form a relatively stable graphite layer 20, a relatively large spraying pressure and time are required. Therefore, in some embodiments, referring to FIG. 5 , the housing assembly 100 may further include an adhesive layer 21 , and the adhesive layer 21 is disposed between the graphite layer 20 and the surface of the middle plate 32 , wherein the thickness of the adhesive layer 21 is less than 0.1mm. Specifically, before coating the graphite layer 20 , the adhesive layer 21 is disposed on the surface of the middle plate 32 , and then graphite powder is coated on the adhesive layer 21 to form the graphite layer 20 . The advantage of this arrangement is that, since the adhesive layer 21 is formed on the surface of the middle plate 32 in advance, when the graphite powder is coated, the adhesive force is greater and the graphite powder can be better adsorbed. At this time, although the adhesive layer 21 is used, the thickness of the adhesive layer 21 is very small and will not affect the Z thermal conductivity of the graphite layer 20 too much. At the same time, the entire graphite layer 20 is formed by spraying, etc. It is also possible to form a thicker graphite layer 20 without using glue.

In this embodiment, compared with the form of directly adhering the graphite sheet to the middle plate 32 through adhesive, the thickness of the adhesive layer 21 used is very small, and only a very thin layer needs to be applied. Only one layer of adhesive is used in the thickness direction, which can still reduce the thickness of the adhesive layer and reduce the thermal resistance in the thickness direction compared with the traditional method of bonding multiple layers of graphite sheets in sequence.

In some embodiments, the first surface 321 or the second surface 322 can also be set as a relatively rough rough plane, which is beneficial to increase the distance between the graphite layer 20 and the first surface 321 or the second surface 322 when the graphite powder is coated. adhesion between.

This embodiment also provides a preparation method of the above-mentioned housing assembly 100, for example, it can be carried out in the following manner:

S10 : providing a middle frame 30 , the middle frame 30 includes a middle plate 32 and a frame 31 , and the frame 31 is surrounded by the middle plate 32 and connected to the middle plate 32 .

In some embodiments, in step S10, the surface of the middle plate 32 can be a completely flat plane. In some other embodiments, in step S10 , grooves 323 may be formed on the surface of the middle plate 32 in advance for disposing the graphite layer 20 . The area of the grooves 323 may be greater than or equal to the cross-sectional area of the graphite layer 20 , and the open areas of the grooves 323 may partially or fully cover the first surface 321 ; or, partially or fully cover the second surface 322 .

S20: Coating graphite powder on the surface of the middle plate 32 according to a predetermined thickness.

The predetermined thickness refers to the design thickness of the graphite layer 20, which can be adjusted according to the thickness space and design requirements of the housing assembly 100, for example, it is designed to be 2.2-4 mm.

For the coating method, reference may be made to the foregoing content, which will not be repeated here. The graphite powder is prepared by: sintering the PI film at high temperature to make it graphitized, and pulverizing to obtain the graphite powder. For the specific preparation method of the graphite powder, reference may be made to the foregoing content, which will not be repeated here.

In some embodiments, step S20 may be performed in the following manner:

An adhesive layer 21 is formed on the surface of the middle plate 32 , the thickness of the adhesive layer 21 is less than or equal to 0.1 mm, and the surface of the adhesive layer 21 is sprayed with graphite powder at a predetermined thickness. The thickness of the adhesive layer 21 cannot be too thick, otherwise the thermal resistance in the thickness direction will be increased. By spraying graphite powder on the adhesive layer 21 to form the graphite layer 20 , the connection strength between the graphite layer 20 and the middle plate 32 can be increased. At the same time: in the initial stage of spraying, the graphite powder is sprayed on the surface of the middle plate 32. Due to the existence of the adhesive layer 21, the graphite powder is more easily attached to the adhesive layer 21, which can increase the adhesion probability of the graphite powder and improve the spraying efficiency. . Compared with directly spraying the graphite powder on the surface of the middle plate 32 , the adhesion probability can be increased, the efficiency can be improved, and the spraying pressure can be correspondingly reduced.

Using the shell assembly 100 prepared in the above manner, since the graphite layer 20 is formed on the surface of the middle plate 32, and the graphite layer 20 is formed by directly spraying graphite powder, it can have a larger thickness and does not need to use Adhesive, the thermal conductivity of the housing assembly 100 in the thickness direction is better. At the same time, the thermal conductivity in the plane direction is also better.

Referring to FIG. 6 , the present embodiment also provides an electronic device 10 , the above-mentioned housing assembly 100 of the electronic device 10 , a heating element 50 and an optional display screen 60 , wherein the heating element 50 is arranged on the middle plate 32 of the middle frame 30 . surface. The heating element 50 is thermally connected to the graphite layer 20. It can be understood that the thermally conductive connection means that the heating element 50 and the graphite layer 20 are connected by direct or indirect contact to realize heat conduction.

The housing assembly 100 further includes a front case 40 and a rear cover 45 . Both the front case 40 and the rear cover 45 are assembled on the middle frame 30 , and the first surface 321 of the middle plate 32 faces the front case 40 and the second surface 322 faces the rear. Cover 45. The display screen 60 is assembled on the middle frame 30 and located on one side of the first surface 321 , and the front case 40 is disposed around the display screen 60 . In this embodiment, the graphite layer 20 is disposed on the first surface 321 , and the heating element 50 is disposed on the second surface 322 .

Please refer to FIG. 6 and FIG. 7 together, the heating element 50 may include one or more first heating elements 51 and one or more second heating elements 52 . The first heating element 51 or the second heating element 52 is, for example, a power supply, and may also be a heating chip or the like. In this embodiment, the power supply is used as the first heating element 51 and the heating chip is used as the second heating element 52 for description. The power supply and the heating chip are both disposed on the second surface 322 corresponding to the graphite layer 20, and the graphite layer 20 can simultaneously correspond to the power supply and the heating chip and conduct heat, so that the heat conducted by the graphite layer 20 is distributed between the first heating element 51 and the second heating element 51. The two heating elements 52 are evenly distributed and conduct heat toward the display screen 60 , and the graphite layer 20 is attached to the surface of the middle plate 32 to transfer the heat to the middle frame 30 . In this embodiment, the graphite layer 20 is located in the gap between the display screen 60 and the middle plate 32, and the thickness of the second surface 322 will not be increased, and the arrangement of other components in the electronic device 10 will not be affected, so it is not necessary to increase the thickness of the second surface 322. Thickness of housing assembly 100 and electronic device 10 .

In some embodiments, the graphite layer 20 may also be disposed on the second surface 322 , and in this case, the power supply and the heating chip are directly disposed on the surface of the graphite layer 20 . In this embodiment, the heating element 50 can be directly attached to the graphite layer 20, and the heat conduction efficiency is higher.

In some embodiments, grooves 323 may be provided on the surface of the middle plate 32 , and the entire graphite layer 100 may be completely embedded in the grooves 323 , so that the thickness of the entire electronic device 10 will not be affected by the graphite layer 20 . At the same time, since the graphite layer 20 is embedded in the groove 323, no adhesive is needed, on the one hand, the thickness of the adhesive layer formed by using the adhesive is saved, and on the other hand, no thermal resistance is formed, and the first heating element 51 and the second heating element 51 and the second heating element The element 52 can be directly attached to the graphite layer 100 to conduct heat, thereby improving the heat transfer efficiency. And because no adhesive is required, when the graphite layer 100 and the first heating element 51 and the second heating element 52 are installed and attached, it is not necessary to apply excessive force to the graphite layer 100 to prevent the graphite layer 100 from being deformed.

When the power supply is working, the heat generated is uniformly heated between the graphite layer 100 and the heating chip. At the same time, during the heat transfer process, due to the improved Z thermal conductivity of the graphite layer 20, the heat can be quickly transferred to the middle frame 30. And conduct conduction toward the side of the middle frame 30 where the display screen 60 is arranged. At the same time, since the thickness of the graphite layer 100 is relatively thin, there is no need to reserve more thickness space for the graphite layer 20 in the middle frame 30, and the electronic device 10 can be designed to be thinner.

In the electronic device 10 using the above-mentioned graphite layer 20, since the thickness of the graphite layer 20 is relatively thin, there is no need to increase the thickness of the electronic device 10, so there is no need to reserve a large space for the thickness inside the middle frame 30, and the electronic device 10 can be lighter and thinner .

The electronic device 10 in the present application may be a mobile phone or smartphone (eg, iPhone TM based, Android TM based phone), portable gaming device (eg Nintendo DS TM, PlayStation Portable TM, Gameboy Advance TM, iPhone TM), laptop Top computers, PDAs, portable Internet devices, music players, and data storage devices, other handheld devices and such as watches, earphones, pendants, earphones, etc. The electronic device 10 may also be other wearable devices (eg, such as electronic glasses, Electronic clothing, electronic bracelets, electronic necklaces, electronic tattoos, head mounted devices (HMDs) for electronic devices 10 or smart watches).

The electronic device 10 may also be any of a plurality of electronic devices 10 including, but not limited to, cellular phones, smart phones, other wireless communication devices, personal digital assistants, audio players, other media players, music Recorders, VCRs, Cameras, Other Media Recorders, Radios, Medical Equipment, Vehicle Transportation Instruments, Calculators, Programmable Remote Controls, Pagers, Laptops, Desktops, Printers, Netbooks, Personal Digital Assistants (PDAs) , Portable Multimedia Players (PMP), Moving Picture Experts Group (MPEG-1 or MPEG-2) Audio Layer 3 (MP3) players, portable medical devices and digital cameras and combinations thereof.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (10)

1. a kind of preparation method of housing unit characterized by comprising

Center is provided, the center includes middle plate and frame, and the frame encloses set on the middle plate and is connected to the middle plate；

Graphite powder is coated in the surface of the middle plate by predetermined thickness, the graphite powder is prepared by following manner: high temperature sintering PI Film makes its graphitization, and crushing obtains the graphite powder.

2. the method according to claim 1, wherein described coat stone in the surface of the middle plate by predetermined thickness Before ink powder, further includes:

Adhesive-layer is formed in the surface of the middle plate, the thickness of adhesive-layer is less than or equal to 0.1mm；

It is described that graphite powder is coated in a manner of spraying in the surface of the middle plate by predetermined thickness, comprising:

Graphite powder is coated in the surface of the adhesive-layer by predetermined thickness.

3. the method according to claim 1, wherein described coat stone in the surface of the middle plate by predetermined thickness Ink powder, comprising:

The graphite powder is coated on to the surface of the middle plate in a manner of spraying or print, and reaches predetermined thickness.

4. the method according to claim 1, wherein described coat stone in the surface of the middle plate by predetermined thickness Before ink powder, further includes:

Groove is formed in the surface of the middle plate；

It is described to coat graphite powder in the surface of the middle plate by predetermined thickness, comprising:

Graphite powder is coated in the groove by predetermined thickness.

5. according to the method described in claim 4, it is characterized in that, the depth of the groove is equal with the predetermined thickness.

6. a kind of housing unit characterized by comprising

Center,；And

Graphite linings, the graphite linings are formed by the surface that graphite powder is coated on the middle plate, and the graphite powder is by following manner system Standby: high temperature sintering PI film makes its graphitization, crushes to obtain the graphite powder.

7. housing unit according to claim 6, which is characterized in that the housing unit further includes front housing, the front housing It is assemblied in the side of the center, the graphite linings are set to the surface towards the front housing of the middle plate.

8. housing unit according to claim 6, which is characterized in that the surface of the middle plate forms groove, the graphite Layer is embedded in the groove.

9. housing unit according to claim 8, which is characterized in that the depth of the thickness of the graphite linings and the groove It is equal.

10. a kind of electronic equipment characterized by comprising

The described in any item housing units of claim 7-9；And

Heater element, the heater element be set to the middle plate and with the thermally conductive connection of the graphite linings.