CN110868823A

CN110868823A - Housing assembly and electronic device

Info

Publication number: CN110868823A
Application number: CN201911120670.6A
Authority: CN
Inventors: 杨鑫
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2020-03-06

Abstract

The application discloses casing subassembly and electron device. The housing assembly includes a chassis and a photonic crystal layer. The photonic crystal layer is disposed on the case. The photonic crystal layer includes first and second nonconductors that are periodically alternately stacked. The photonic crystal layer is used for reflecting light rays with a wave band of 0.2-2.5 mu m and improving the radiance of a wave band of 8-14 mu m. In the case assembly and the electronic device according to the embodiments of the present application, on one hand, the photonic crystal layer can selectively reflect light rays of a 0.2 μm-2.5 μm band concentrated by solar energy, thereby resisting heating of the electronic device by solar radiation; on the other hand, the photonic crystal layer can improve the radiance of 8-14 μm wave bands, and fully utilizes the passive radiation refrigeration of 8-14 μm wave bands, so that the effect of enhancing the infrared heat radiation effect is achieved, and the heat dissipation capacity of the electronic device is improved.

Description

Housing assembly and electronic device

Technical Field

The present application relates to the field of terminal heat dissipation technologies, and more particularly, to a housing assembly and an electronic device.

Background

With the development of chips in electronic devices, the functions of the electronic devices are more and more powerful, and accordingly, the power consumption of the electronic devices is also higher and higher. The high power consumption generated when the chip operates directly causes the temperature of the area where the chip is located to rise sharply. How to improve the heat dissipation capability of the electronic device becomes an urgent problem to be solved.

Disclosure of Invention

The embodiment of the application provides a shell assembly and an electronic device.

The shell assembly comprises a shell and a photonic crystal layer, wherein the photonic crystal layer is arranged on the shell and comprises a first non-conductor and a second non-conductor which are alternately stacked periodically, and the photonic crystal layer is used for reflecting light rays in a wave band of 0.2-2.5 microns and improving the radiance of the wave band of 8-14 microns.

The electronic device of the embodiment of the application comprises a shell assembly and a functional element, wherein the functional element is mounted on the shell assembly; the shell assembly comprises a shell and a photonic crystal layer, wherein the photonic crystal layer is arranged on the shell and comprises a first non-conductor and a second non-conductor which are alternately stacked periodically, and the photonic crystal layer is used for reflecting light rays with a wave band of 0.2-2.5 mu m and improving the radiance of the wave band of 8-14 mu m.

In the case assembly and the electronic device according to the embodiments of the present application, on one hand, the photonic crystal layer can selectively reflect light rays of a 0.2 μm-2.5 μm band concentrated by solar energy, thereby resisting heating of the electronic device by solar radiation; on the other hand, the photonic crystal layer can improve the radiance of 8-14 μm wave bands, and fully utilizes the passive radiation refrigeration of 8-14 μm wave bands, so that the effect of enhancing the infrared heat radiation effect is achieved, and the heat dissipation capacity of the electronic device is improved.

Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic perspective view of an electronic device according to some embodiments of the present disclosure;

FIG. 2 is a schematic plan view of an electronic device according to some embodiments of the present application;

FIG. 3 is a schematic plan view of an electronic device according to some embodiments of the present application;

FIG. 4 is a schematic structural diagram of a housing of certain embodiments of the present application;

FIG. 5 is a schematic structural view of a housing assembly according to certain embodiments of the present application;

FIG. 6 is a schematic structural view of a housing assembly according to certain embodiments of the present application;

FIG. 7 is a schematic structural view of a photonic crystal layer according to certain embodiments of the present application;

FIG. 8 is a schematic structural view of a photonic crystal layer according to certain embodiments of the present application;

FIG. 9 is a schematic illustration of a solar radiation spectral power distribution of certain embodiments of the present application;

FIG. 10 is a graph showing the transmission of electromagnetic waves through the atmosphere for a plurality of spectral ranges in accordance with certain embodiments of the present application;

FIG. 11 is a schematic representation of the optical properties of a photonic crystal layer according to certain embodiments of the present application;

FIG. 12 is a schematic illustration of energy flow versus radiant cooling for certain embodiments of the present application;

FIG. 13 is a graphical representation of net radiative cooling power as a function of equilibrium temperature for a photonic crystal layer according to certain embodiments of the present application;

FIG. 14 is a graphical representation of the equilibrium temperature of a photonic crystal layer according to certain embodiments of the present application as a function of heat transfer coefficient.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

With the increase of the power consumption of the mobile phone, the heat dissipation of the mobile phone becomes a key factor limiting the performance of the mobile phone. The particularity of heat dissipation of the mobile phone is to ensure that the temperature of the chip is reduced (i.e., the heat of the chip can be conducted out through a material with low thermal resistance and high thermal conductivity) and that the temperature of the mobile phone rear cover is reduced (i.e., the heat conduction from the mobile phone chip to the mobile phone rear cover is reduced through a heat insulation structure design or a heat insulation material). However, these two requirements are contradictory to each other in terms of heat dissipation, and if the temperature of the chip is to be lowered, it is necessary to conduct heat to the back cover more quickly, which will cause the temperature of the back cover to rise; if the temperature of the rear cover is to be lowered, the heat must be confined inside the handset, which in turn causes the temperature of the chip to rise.

In order to meet the heat dissipation requirement of the mobile phone, the current technical direction is generally as follows: the heat is uniformly distributed in the mobile phone as much as possible, the surface area of the mobile phone is fully utilized for heat dissipation, local hot spots of the rear cover of the mobile phone are eliminated, the working temperature of the chip is ensured, and the temperature of the rear cover of the mobile phone is reduced as much as possible. From a physical point of view, there are three ways of heat propagation, namely conduction, convection, and radiation. Due to the limitation of the size of the mobile phone, convection is difficult to utilize (convection requires air flow, namely a fan, and the design of a fan structure inside the mobile phone is difficult), so two modes of conduction and radiation are considered. In the two ways, heat is conducted to be homogenized (such as graphene, Vapor Chamber (VC), heat pipe, etc. are all the principles), and meanwhile, heat can be transmitted to the rear cover of the mobile phone through the chip and dissipated. The heat radiation effect is slightly weaker than the conduction effect, but because the gaps between the internal structures of the mobile phone are small and the radiation angle coefficient is large, the heat radiation also plays an important role in the heat radiation of the mobile phone.

Currently, there are a number of techniques for reducing the junction temperature of a mobile phone chip and the temperature of a mobile phone rear cover by using heat conduction, such as synthetic graphite, graphene, VC, heat pipes, and the like. The principle of synthesizing graphite and graphene is to make heat uniform by utilizing the high thermal conductivity (usually >1000W/mK) of graphene materials in the plane and eliminate local hot spots. The principle of VC is the same as that of a heat pipe, the soaking capacity is improved by utilizing the phase change of pure water, and compared with synthetic graphite and graphene, the VC has higher heat flux (namely, the heat removal capacity).

The current solutions are basically limited to the traditional heat dissipation method, i.e. heat dissipation is performed through the path of "chip-shielding cover-mobile phone shell-environment". The dimensionless number for measuring the heat dissipation capability of the mobile phone is the heat equalization Coefficient (CTS), and the closer the CTS is to 1, the better the heat equalization capability of the mobile phone is. At present, the CTS of the mobile phone with good heat dissipation has reached more than 0.85 and is basically close to the limit, so that the traditional heat dissipation path has reached the bottleneck and the temperature of the mobile phone cannot be further reduced.

Referring to fig. 1 and fig. 2, an electronic device 1000 and a housing assembly 100 are provided in the present embodiment.

Referring to fig. 1, an electronic device 1000 according to an embodiment of the present disclosure includes a housing assembly 100 and a functional element 200. The electronic device 1000 may be a mobile phone, a tablet computer, a notebook computer, an intelligent bracelet, an intelligent watch, an intelligent helmet, an intelligent glasses, and the like. In the embodiment of the present application, the electronic device 1000 is a mobile phone as an example, and it is understood that the specific form of the electronic device 1000 is not limited to the mobile phone.

The functional element 200 is mounted on the housing assembly 100, that is, the housing assembly 100 may serve as a mounting carrier for the functional element 200. The housing assembly 100 may provide protection for the functional element 200 from dust, falling, water, etc. The functional element 200 may be a display screen, a camera, a receiver, a chip, etc.

Referring to fig. 2 and 3, a housing assembly 100 according to an embodiment of the present disclosure includes a case 20 and a photonic crystal layer 14.

The housing 20 may be a rear cover of the electronic device 1000, for example, when the electronic device 1000 is a mobile phone, the housing 20 is a rear cover of the mobile phone. The photonic crystal layer 14 is disposed on the case 20.

Referring to fig. 3-5, in one example, the housing 20 may include opposing inner and

outer surfaces

21, 22. The inner surface 21 may be formed with a receiving cavity 212 for receiving the functional element 200.

The photonic crystal layer 14 is disposed at the outer surface 22. Specifically, the photonic crystal layer 14 may be formed on the outer surface 22 by a Chemical Vapor Deposition (CVD) method. The chemical vapor deposition method can be used for obtaining a coating (namely the photonic crystal layer 14) with high purity, good compactness and good crystallization, and the photonic crystal layer 14 has strong adhesive force on the outer surface 22 and is not easy to fall off.

Referring to fig. 6, in another example, the housing 20 may include a cover 23 and a light-transmissive protective layer 24. The cover 23 includes opposing first inner and

outer surfaces

231, 232. The protective layer 24 includes opposing second inner and

outer surfaces

241, 242. The first outer surface 232 is opposite the second inner surface 241. The first inner surface 231 may be formed with a receiving chamber (not shown) for receiving the functional element 200. The protective layer 24 may be protective glass, which has the advantages of high hardness, less scratch, beautiful appearance, low cost, good hand feeling, and the like, and is beneficial to improving the experience of a user holding the casing 20.

The photonic crystal layer 14 is located between the first outer surface 232 and the second inner surface 241. Specifically, the photonic crystal layer 14 may be disposed at the first outer surface 232 or at the second inner surface 241. Preferably, the photonic crystal layer 14 may be disposed on the first outer surface 232, so that the photonic crystal layer 14 can still function on the lid 23 when the protective layer 24 is peeled off or damaged. The photonic crystal layer 14 may be formed on the first outer surface 232 by a chemical vapor deposition method. The chemical vapor deposition method can be used for obtaining a coating (namely the photonic crystal layer 14) with high purity, good compactness and good crystallization, and the photonic crystal layer 14 has strong adhesive force on the first outer surface 232 and is not easy to fall off.

In the embodiment of the present application, since the protection layer 24 is transparent, the function of the light reflected by the photonic crystal layer 14 (which will be described in detail later) is not substantially affected, and the photonic crystal layer 14 is located between the cover 23 and the protection layer 24, the protection layer 24 can also protect the photonic crystal layer 14 to a certain extent, for example, the photonic crystal layer 14 is prevented from being scratched or the photonic crystal layer 14 falls off.

It can be understood that, for the electronic device 1000, the power consumption generated during the operation of the chip is generally high, and the generated heat is also large, so that the photonic crystal layer 14 may be further disposed at the position corresponding to the chip of the chassis 20 (for example, the position corresponding to the chip of the outer surface 22, or the position corresponding to the chip of the first outer surface 232) to sufficiently dissipate the heat generated by the chip, and the chassis 20 of the electronic device 1000 does not have the problem of local overheating. In addition, the planar area of the photonic crystal layer 14 covering the outer surface 22 or the first outer surface 232 may be larger than the area of the chip to further improve the heat dissipation effect. Of course, the photonic crystal layer 14 may cover the entire outer surface 22 or the first outer surface 232, and the photonic crystal layer 14 is matched with the design of the chassis 20 to ensure the heat dissipation effect of the electronic device 1000.

Referring to fig. 7 and 8, the photonic crystal layer 14 includes first nonconductors 141 and second nonconductors 142 that are alternately stacked periodically. The photonic crystal layer 14 is used to reflect light of a band of 0.2 to 2.5 μm and to increase the radiance of a band of 8 to 14 μm.

In the case assembly 100 and the electronic device 1000 according to the embodiment of the present application, on one hand, the photonic crystal layer 14 can selectively reflect light rays in a band of 0.2 μm to 2.5 μm concentrated by solar energy, so as to resist heating of the electronic device 1000 by solar radiation; on the other hand, the photonic crystal layer 14 can improve the radiance of the wave band of 8 μm to 14 μm, and fully utilizes the passive radiation refrigeration of the wave band of 8 μm to 14 μm, thereby achieving the effect of enhancing the infrared heat radiation effect and improving the heat dissipation capability of the electronic device 1000.

Referring to fig. 7 and 8, the photonic crystal layer 14 includes first nonconductors 141 and second nonconductors 142 alternately stacked periodically in a predetermined direction. The predetermined direction may be a direction from the outer surface 22 to the inner surface 21 (or a direction from the second outer surface 242 to the first inner surface 231) of the housing 20, or a thickness direction of the electronic device 1000. In the embodiment of the present application, the photonic crystal layer 14 adopts a photonic crystal structure in which the first nonconductor 141 and the second nonconductor 142 are periodically and alternately stacked as a reflective layer to provide high reflection characteristics of the solar spectrum.

The photonic crystal layer 14 is used to reflect light in a wavelength band of 0.2 μm to 2.5 μm. That is, the wavelength of light for reflection by the photonic crystal layer 14 is any value between 0.2 μm and 2.5 μm. For example, the wavelength of light used for reflection by the photonic crystal layer 14 is 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2 μm, 2.2 μm, 2.4 μm, 2.5 μm, or the like. In the embodiment of the present application, the photonic crystal layer 14 can selectively reflect light rays in a band of 0.2 μm to 2.5 μm focused by solar energy, thereby resisting heating of the electronic device 1000 by solar radiation.

The photonic crystal layer 14 also serves to increase the emissivity in the 8-14 μm band (the emissivity of the housing 20 of the electronic device 1000 in the 8-14 μm band can be increased). That is, the wavelength of the photonic crystal layer 14 for increasing the emissivity is any value between 8 μm and 14 μm. For example, the wavelength of the photonic crystal layer 14 for increasing emissivity is 8 μm, 8.6 μm, 9.2 μm, 9.8 μm, 10.4 μm, 11 μm, 11.6 μm, 12.2 μm, 12.8 μm, 13.4 μm, 14 μm, or the like. In the embodiment of the application, the photonic crystal layer 14 can improve the radiance of the wave band from 8 μm to 14 μm, and the passive radiation refrigeration of the wave band from 8 μm to 14 μm is fully utilized, so that the effect of enhancing the infrared heat radiation effect is achieved, and the heat dissipation capability of the electronic device 1000 is improved.

It can be understood that, at present, mobile phones are used outdoors more and more, heat power consumption of internal chips is not only considered for heat dissipation of mobile phones, and the heating effect of solar radiation on mobile phones also gradually becomes a factor of overheating of mobile phones. The solar spectral characteristics of standard atmospheric quality (Airmass, AM)1.5 approximate the black body radiation spectrum at a temperature of 5762K, with a total radiation dose of about 1000W/m²99% of the energy is concentrated in the short-wave region of 0.2-2.5 μm. The greenhouse effect is that the glass has high penetration ratio for the heat radiation with the wavelength below 3 μm, and the penetration ratio for the heat radiation with the wavelength more than 3 μm is suddenly reduced, so most of the solar radiation energy passes through the glass to enter the chamber, and the long-wave radiation emitted by the chamber is blocked in the chamber, so that the temperature in the chamber is increased.

In the embodiment of the present application, for the case 20 (e.g., a rear cover of a mobile phone) of the electronic device 1000, light rays in a band of 0.2 μm to 2.5 μm concentrated by solar energy (most of solar radiation is reflected) are selectively reflected by the photonic crystal layer 14, so as to resist the heating of the case 20 of the electronic device 1000 by solar radiation, and prevent the electronic device 1000 from overheating due to the heating of the case 20 of the electronic device 1000 by solar radiation. Meanwhile, the emissivity or radiance of a wave band of 8-14 microns is improved through the photonic crystal layer 14, and redundant heat is transmitted to the outer space by utilizing an atmospheric window under the condition of not consuming any energy, so that passive selective radiation refrigeration is realized.

The number of the periods in which the first nonconductor 141 and the second nonconductor 142 are alternately stacked may be greater than or equal to 5. That is, the number of periods in which the first nonconductor 141 and the second nonconductor 142 are alternately stacked periodically is an arbitrary value greater than or equal to 5. For example, the number of the periods in which the first nonconductor 141 and the second nonconductor 142 are alternately stacked is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and the like. Taking the number of the periods in which the first nonconductor 141 and the second nonconductor 142 are alternately stacked periodically as 5 as an example, the following are sequentially performed along the predetermined direction: a first nonconductor 141, a second nonconductor 142, and an outer surface 22. When the number of the periods in which the first nonconductors 141 and the second nonconductors 142 are periodically alternately stacked is greater than or equal to 5, the photonic crystal layer 14 can have a good reflection effect and a high reflection characteristic to the solar spectrum.

Preferably, the number of the first nonconductor 141 and the second nonconductor 142 that are alternately stacked periodically is 10. In this way, the relationship between the thickness of the photonic crystal layer 14 and the reflective effect of the photonic crystal layer 14 on the solar spectrum can be balanced, namely: so that the photonic crystal layer 14 has a smaller thickness and a better reflection effect on the solar spectrum. It is understood that when the number of the periods in which the first nonconductors 141 and the second nonconductors 142 are periodically alternately stacked is small, the photonic crystal layer 14 may not achieve a good reflection effect on the solar spectrum; when the number of periods in which the first nonconductors 141 and the second nonconductors 142 are periodically and alternately stacked is large, the thickness of the photonic crystal layer 14 may be large, and when the photonic crystal layer 14 is disposed on the chassis 20, the aesthetic appearance and the utility of the electronic device 1000 may be affected, and the user experience may be affected.

Referring to fig. 7, in one example, the first nonconductor 141 is titanium dioxide (TiO) and the second nonconductor 142 is silicon dioxide (TiO). At this time, the titanium dioxide and the silicon dioxide are alternately stacked periodically in a predetermined direction, that is, in the predetermined direction, sequentially: titanium dioxide, silicon dioxide, … …, titanium dioxide, silicon dioxide, housing 20.

Referring to fig. 8, in another example, the first nonconductor 141 is silicon dioxide and the second nonconductor 142 is titanium dioxide. At this time, the silica and the titania are alternately stacked periodically in a predetermined direction, that is, in the predetermined direction, sequentially: silica, titania, … …, silica, titania, housing 20.

It should be noted that, in the above embodiments, both the titania and the silica adopt the nano-scale structure, i.e., the titania nano-layer and the silica nano-layer. In addition, since the material used for the first nonconductor 141 and the second nonconductor 142 does not involve a conductor, the antenna signal transmission of the electronic device 1000 is not affected, and the application to the electronic device 1000 having an antenna is facilitated.

The thickness of the photonic crystal layer 14 (the total thickness of the first nonconductors 141 and the second nonconductors 142 that are periodically alternately stacked) may be greater than or equal to 6 μm. That is, the thickness of the photonic crystal layer 14 is any value greater than or equal to 6 μm. For example, the thickness of the photonic crystal layer 14 is 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, or the like. When the thickness of the photonic crystal layer 14 is greater than or equal to 6 μm, the thicknesses of the single-layer first nonconductor 141 and the single-layer second nonconductor 142 are not too thin, which facilitates the process manufacturing and ensures the product yield and the reflection effect.

The principle and effect of the photonic crystal layer 14 according to the embodiment of the present application will be described in detail below with reference to fig. 9 to 14.

Spectral energy distribution of solar radiationAs shown in fig. 9. Most of the energy is concentrated between 0.2 μm and 2.5 μm, i.e. the influence of solar radiation on the temperature of the object is mainly determined by the radiation capacity in this wavelength interval, while the total energy of the solar radiation is 1000W/m based on the AM1.5 solar spectrum²This would be a significant energy consumption for refrigeration technology. In the embodiment of the present application, light in a wavelength range of 0.2 μm to 2.5 μm is blocked outside the case 20 of the electronic device 1000 by the selective reflection action of the photonic crystal layer 14, and the heating action of solar radiation on the case 20 is eliminated. The reason for selecting the photonic crystal layer 14 is that the photonic crystal structure can utilize the alternate stacking of the plurality of non-conductors to realize the effect of the metal reflective layer, which avoids the interference of the metal reflective layer to the antenna of the electronic device 1000, so that the design and the use of the housing 20 of the electronic device 1000 are more convenient.

The embodiment of the present application also utilizes the atmospheric window to fully utilize the radiation heat dissipation of the casing 20 of the electronic device 1000. The atmospheric window refers to a spectral region in which the transmittance of electromagnetic waves is high when the electromagnetic waves transmit through the atmosphere. As shown in fig. 10, the atmospheric window exists in a plurality of spectral ranges. Wherein 8 μm-14 um is a thermal infrared band, the thermal radiation peak wavelength of an object on the earth is generally distributed in the band region, and meanwhile, in the band range of 8 μm-14 um, the atmosphere is highly transparent, that is, the atmospheric layer has high transmittance (> 80%) to infrared radiation and low absorption rate. Therefore, objects on the earth can utilize an atmospheric window waveband of 8-14 um to radiate heat to the outer space in the form of electromagnetic waves through radiation cooling, and passive radiation refrigeration is realized.

The infrared heat radiation characteristic of this application embodiment through photonic crystal structure (being photonic crystal layer 14) regulation and control material, does not use the metal reflection stratum, avoids under the condition of the antenna signal transmission interference to electron device 1000, promotes the casing 20 of electron device 1000 reflectivity in the solar spectrum to realize the high emissivity of the full wave band in 8 mu m ~ 14 um. The optical characteristics of the photonic crystal layer 14 are shown in fig. 11. The average reflectivity of the photonic crystal layer 14 in a solar spectrum waveband of 0.2-2.5 microns reaches 97%, solar radiation energy is not absorbed basically, the average emissivity in an atmospheric window waveband reaches 90%, and passive radiation refrigeration can be realized through an atmospheric window.

The effect of the photonic crystal layer 14 of the present embodiment on temperature will be described below by introducing the concept of radiation cooling capacity. The calculation of radiant cooling can be represented by the energy flow as shown in fig. 12. Wherein q is_radRadiant energy of a radiator, q_sunSolar radiation absorbed by the radiator, q_skyAtmospheric radiation absorbed by the radiator, q_lossInherent heat losses (e.g., still air convection, air heat conduction, etc.). The calculation of the radiant cooling capacity satisfies the following formula, q_net-coolingNamely the radiation refrigerating capacity. For example, for a low-humidity clear air environment, the net radiation cooling power of the objects on the earth can be as high as 140W/m at the ambient temperature of 300K²The cooling power only takes into account the radiation dose of the object in the atmospheric window.

q_net-cooling＝q_rad(T_r)－q_sky－q_sun－q_loss。

Based on the above formula, the effect of the non-radiative factors is not considered, and the net radiation refrigeration power of the photonic crystal layer 14 is theoretically calculated to change with the ambient temperature, and the effect is shown in fig. 13. As can be seen from FIG. 13, the theoretical value of the net radiation refrigeration power of the photonic crystal layer 14 can reach 119.6W/m at the room temperature of 300K². By way of comparison, without the photonic crystal layer 14 of the embodiments of the present application, the theoretical value of net radiation refrigeration power is-861.4W/m²I.e. the temperature will gradually increase due to the absorption of solar energy.

The net radiation power increases with increasing temperature. Meanwhile, the function of the photonic crystal layer 14 is passive radiation refrigeration, the radiation heat dissipation capacity of the photonic crystal layer 14 can be considered when the refrigeration effect is considered, and the balance temperature of the photonic crystal layer 14 can be considered, namely the lowest temperature which can be reached by the photonic crystal layer 14 through spontaneous radiation refrigeration. Meanwhile, the practicability is considered, the influence of the loss power of the photonic crystal layer 14 on the refrigeration efficiency of the photonic crystal layer 14 needs to be considered, and the theoretical equilibrium temperature which can be reached by the photonic crystal layer 14 when the ambient temperature is 300KThe relationship with the heat transfer coefficient is shown in FIG. 14. As can be seen from fig. 14, the photonic crystal layer 14 can realize a cooling effect of about 38K below the ambient temperature without considering heat loss, and as the heat transfer coefficient increases, the practical condition (the convection heat transfer coefficient is about 6W/m) is considered²K) And the cooling effect of about 12.7K can be realized.

In summary, the photonic crystal layer 14 is added on the chassis 20 of the electronic device 1000 in the embodiment of the present disclosure, so as to achieve the functions of selectively enhancing the solar spectrum reflection and increasing the emissivity of the atmospheric window, and eliminate the defects that the electronic device 1000 is easily overheated by solar radiation and heat cannot be dissipated by radiation. In addition, the material used for the photonic crystal layer 14 does not involve a conductor, and antenna interference caused by a conventional metal plating layer can be effectively avoided.

In the description of the present specification, reference to the description of the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "one embodiment," "specific examples," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations of the above embodiments may be made by those of ordinary skill in the art within the scope of the present application, which is defined by the claims and their equivalents.

Claims

1. A housing assembly, comprising:

a housing; and

the photonic crystal layer is arranged on the shell and comprises a first non-conductor and a second non-conductor which are alternately stacked periodically, and the photonic crystal layer is used for reflecting light rays with a wave band of 0.2-2.5 mu m and improving the radiance of the wave band of 8-14 mu m.

2. The housing assembly of claim 1 wherein the first non-conductor is silicon dioxide and the second non-conductor is titanium dioxide; or

The first nonconductor is titanium dioxide and the second nonconductor is silicon dioxide.

3. The housing assembly of claim 1 wherein the first nonconductor and the second nonconductor are stacked periodically in an alternating order of greater than or equal to 5.

4. The housing assembly of claim 3 wherein the first nonconductor and the second nonconductor are stacked alternately in cycles of 10.

5. The housing assembly of claim 1 wherein the photonic crystal layer has a thickness greater than or equal to 6 μ ι η.

6. The housing assembly of claim 1 wherein the chassis includes opposing inner and outer surfaces, the photonic crystal layer being disposed on the outer surface.

7. The housing assembly of claim 6 wherein the photonic crystal layer is formed on the outer surface by chemical vapor deposition.

8. The housing assembly of claim 1, wherein the chassis includes a cover and a light transmissive protective layer, the cover including first and second opposing inner and outer surfaces, the protective layer including second and second opposing outer surfaces, the first outer surface opposing the second inner surface, the photonic crystal layer being positioned between the first and second inner surfaces.

9. The housing assembly of claim 8 wherein the photonic crystal layer is formed on the first outer surface by chemical vapor deposition.

10. An electronic device, comprising:

the housing assembly of any one of claims 1 to 9; and

a functional element mounted on the housing assembly.