CN108177411B - Mobile terminal backplane and preparation method thereof, and mobile terminal - Google Patents

Abstract

The invention provides a mobile terminal backboard, a preparation method thereof and a mobile terminal. Wherein, the mobile terminal backplate includes: a heat conductive layer containing a thermoplastic resin; a protective layer provided on one surface of the heat conductive layer, the protective layer containing diamond therein. The mobile terminal backboard is simple in structure, easy to realize, high in yield, low in cost, high in toughness, high in damage tolerance, high in relative dielectric constant, high in signal shielding resistance and high in impact resistance, and the diamond is added into the protective layer to enable the mobile terminal backboard to be good in abrasion resistance and thermal conductivity, so that the problem of heat generation of the mobile terminal is solved.

Description

Mobile terminal backplane and preparation method thereof, and mobile terminal

technical field

The present invention relates to the technical field of materials, and in particular, to a mobile terminal backplane, a preparation method thereof, and a mobile terminal.

Background technique

In August 2017, Qualcomm announced that it had completed the first 5G connection test on mobile terminals. In addition, Qualcomm also launched the first 5G smartphone reference design. In September 2017, Deutsche Telekom officially announced the launch of the world's first 5G commercial network with Huawei. This is the world's first government and enterprise to launch complete 5G network technology! The prelude to the 5G communication era has begun, and mobile terminals will usher in another revolution.

However, at present, most mobile terminal backplanes are made of metal. Due to the electromagnetic shielding effect of metal, it is difficult for signals to pass through the mobile terminal. At the same time, wireless charging is becoming more and more popular, and the metal backplane of mobile terminals will prevent the magnetic field from penetrating. However, wireless charging is not possible. Therefore, the current backplane of the mobile terminal limits the development of the 5G era and the realization of wireless charging, and cannot meet the growing demands of consumers.

Therefore, the current mobile terminal backplane still needs to be improved.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to provide a mobile terminal backplane with a relatively large relative permittivity, strong anti-signal shielding ability, strong thermal conductivity or low cost.

In one aspect of the present invention, the present invention provides a mobile terminal backplane. According to an embodiment of the present invention, the mobile terminal backplane includes: a thermal conductive layer, the thermal conductive layer contains at least one of graphene or graphite oxide, and a thermoplastic resin; a protective layer, the protective layer is disposed on the thermal conductive layer on one surface of the layer, and the protective layer contains diamond and the thermoplastic resin. The inventors found that the mobile terminal backplane has a simple structure, is easy to implement, has high yield, low cost, high toughness, high damage tolerance, high temperature resistance, good flame retardant performance, good impact resistance, and has a relatively low cost. High relative dielectric constant, strong anti-signal shielding ability, can well meet the technical requirements of 5G communication, adding graphene or graphene oxide to the thermal layer can improve the thermal conductivity and relative dielectric constant of the mobile terminal backplane , adding diamond in the protective layer makes the wear resistance and thermal conductivity of the mobile terminal backplane better, which is beneficial to improve the heating problem of the mobile terminal.

According to an embodiment of the present invention, the thickness of the thermally conductive layer is 2-50 times the thickness of the protective layer. Therefore, the heat conduction performance of the backplane of the mobile terminal is better, which is beneficial to improve the heating problem of the mobile terminal, and at the same time, it can effectively protect the mobile terminal.

According to an embodiment of the present invention, the thickness of the thermally conductive layer is 100-800 microns, and the thickness of the protective layer is 5-100 microns. Therefore, the heat conduction performance of the backplane of the mobile terminal is better, which is beneficial to improve the heating problem of the mobile terminal, and at the same time, it can play a role of protecting the mobile terminal.

According to an embodiment of the present invention, the thermoplastic resin includes at least one of polycarbonate (PC) and polymethyl methacrylate (PMMA). As a result, thermoplastic resins have a wide range of sources, do not contain harmful substances, meet RoHS requirements, have better mechanical properties, have high tensile strength and flame retardant strength, high toughness, impact resistance and damage tolerance, and are chemically stable. It has strong performance, long service life, high temperature resistance, good dimensional stability, easy processing and molding, and low cost.

According to an embodiment of the present invention, the thermally conductive layer and the protective layer further independently include at least one of the following: a ceramic powder; a flame retardant; and an auxiliary agent. Therefore, adding ceramic powder can improve the relative dielectric constant, thermal conductivity or anti-wear performance of the mobile terminal backplane, adding a flame retardant can improve the flame retardant performance of the mobile terminal backplane, and adding an auxiliary agent can make the mobile terminal backplane Easy to form and long service life.

According to an embodiment of the present invention, the ceramic powder includes at least one of alumina and zirconia. In this way, the thermal conductivity of the thermally conductive layer or the protective layer can be effectively improved, and the thermally conductive layer or the protective layer has higher relative permittivity, hardness and wear resistance, and stronger anti-signal shielding ability.

According to an embodiment of the present invention, the zirconia includes first zirconia particles and second zirconia particles, wherein the particle size of the first zirconia particles is 5-20 times the particle size of the second zirconia particles times, and the maximum particle size of the first zirconia particles is not greater than 30 microns. Therefore, the zirconia with the above particle size can further improve the hardness, wear resistance and bending strength of the mobile terminal backplane, and is uniformly dispersed, easy to add, and easy to process.

According to an embodiment of the present invention, the mass ratio of the first zirconia particles to the second zirconia particles is 1:(0.5-2); preferably 1:1. Therefore, the mobile terminal backplane containing the above-mentioned zirconia particle size has better hardness, wear resistance and bending strength, better dispersion uniformity, and easier addition and processing.

According to an embodiment of the present invention, the alumina is α-type alumina. Therefore, the α-type alumina has better thermal conductivity, high electrical resistivity, and good insulating properties.

According to an embodiment of the present invention, the alumina includes first alumina particles and second alumina particles, wherein the particle size of the first alumina particles is 5-20 times the particle size of the second alumina particles times, and the maximum particle size of the first alumina particles is not greater than 30 microns. Therefore, the alumina with the above particle size can further improve the hardness, wear resistance, relative permittivity and thermal conductivity of the mobile terminal backplane, and it is easier to adjust the permittivity and easier to process.

According to an embodiment of the present invention, the shape of the first alumina particles is spherical or quasi-spherical, and the shape of the second alumina particles is an irregular shape. Therefore, the alumina with the above shape has better dispersion uniformity, is easier to add and process, and can further improve the hardness, wear resistance, relative permittivity and thermal conductivity of the mobile terminal backplane.

According to an embodiment of the present invention, the mass ratio of the first alumina particles to the second alumina particles is 1:(0.5-2); preferably 1:1. Therefore, the mobile terminal backplane containing the above-mentioned alumina particle size has better hardness, wear resistance, relative permittivity and thermal conductivity.

According to an embodiment of the present invention, the particle size of the diamond is 10 nanometers-2 micrometers, preferably 700-1000 nanometers. Therefore, the thermal expansion coefficient of the mobile terminal backplane containing the above-mentioned diamond particle size is small, and the thermal conductivity of the mobile terminal backplane increases with the increase of the diamond particle size within the above-mentioned particle size range, and the thermal conductivity is better. Better uniformity and better wear resistance, thereby improving the performance of the mobile terminal backplane.

According to an embodiment of the present invention, the thermally conductive layer comprises: 5-50 parts by weight of thermoplastic resin, 1-10 parts by weight of at least one of graphene or graphene oxide, 10-40 parts by weight of zirconia, and 10-40 parts by weight of aluminum oxide. 40 parts by weight, 5-15 parts by weight of a flame retardant, 0.1-5 parts by weight of a coupling agent, and 0.1-5 parts by weight of an anti-aging agent, wherein the content of the graphene in the thermally conductive layer is not more than 5 wt %. According to some preferred embodiments of the present invention, the thermally conductive layer comprises: 30-40 parts by weight of thermoplastic resin, 5-10 parts by weight of at least one of graphene or graphene oxide, 10-20 parts by weight of zirconium oxide, and aluminum oxide 30-40 parts by weight, 5-15 parts by weight of flame retardant, 1-3 parts by weight of coupling agent, 1-3 parts by weight of anti-aging agent, wherein the content of the graphene in the thermal conductive layer is not more than 5wt% . Therefore, adding graphene or graphene oxide to the thermal conductive layer makes the thermal conductive layer have a relatively large relative permittivity, thereby making it have better anti-signal shielding performance, and each component in the thermal conductive layer is within the above-mentioned ratio range. The internal heat conduction effect is better, the problem of heating of the mobile terminal is effectively improved, and the use performance is better.

According to an embodiment of the present invention, the protective layer includes: 5-50 parts by weight of thermoplastic resin, 1-15 parts by weight of diamond, 10-40 parts by weight of zirconia, 10-40 parts by weight of alumina, and 5-15 parts by weight of flame retardant parts by weight, 0.1-5 parts by weight of coupling agent, and 0.1-5 parts by weight of anti-aging agent. According to some preferred embodiments of the present invention, the protective layer includes: 20-30 parts by weight of thermoplastic resin, 5-15 parts by weight of nano-diamond, 10-30 parts by weight of zirconia, 20-40 parts by weight of alumina, and flame retardant 5-15 parts by weight, 1-3 parts by weight of coupling agent, and 1-5 parts by weight of anti-aging agent. Therefore, adding diamond into the protective layer can make the protective layer have strong wear resistance and better thermal conductivity, and the relative permittivity of each component of the protective layer within the above ratio range is large, and the anti-signal Strong shielding ability, high hardness, high bending strength and good performance.

In another aspect of the present invention, the present invention provides a mobile terminal. According to an embodiment of the present invention, the mobile terminal includes the aforementioned mobile terminal backplane. The mobile terminal has all the features and advantages of the aforementioned mobile terminal backplane, which will not be repeated here.

In another aspect of the present invention, the present invention provides a method for preparing the aforementioned mobile terminal backplane. According to an embodiment of the present invention, the method includes: subjecting the raw material for forming the thermal conduction layer to a first extrusion treatment to obtain a first sheet; subjecting the raw material for forming a protective layer to a second extrusion treatment to obtain a second sheet; The first sheet and the second sheet are hot-pressed to obtain the mobile terminal backplane. The inventors found that the method is simple and convenient to operate, easy to implement, and has a high yield of the prepared mobile terminal backplane, which has all the features and advantages of the mobile terminal backplane described above, and will not be repeated here.

Description of drawings

FIG. 1 is a schematic structural diagram of a backplane of a mobile terminal in an embodiment of the present invention.

FIG. 2 is a schematic flowchart of preparing a mobile terminal backplane in an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below. The embodiments described below are exemplary, only for explaining the present invention, and should not be construed as limiting the present invention. If no specific technique or condition is indicated in the examples, the technique or condition described in the literature in the field or the product specification is used. The reagents or instruments used without the manufacturer's indication are conventional products that can be obtained from the market.

The present invention is accomplished based on the following knowledge and findings of the inventors:

In order to transmit the signal to the mobile terminal more quickly, there are several non-metallic material solutions for the backplane of the mobile terminal: 1. Glass material: three-dimensional (3D) glass, 2.5-dimensional (2.5D) or two-dimensional (2D) glass, decorative The process includes a decorative film (Deco-film) scheme, as well as a spraying scheme; 2. Composite board scheme: polycarbonate (PC)/polymethyl methacrylate (PMMA) composite sheet scheme; 3. Ceramic scheme: with back plate Frame-integrated ceramics (unibody), but affected by production capacity and yield, plan 3 is currently the most expensive plan. The anti-signal shielding capabilities of the mobile terminal backplane materials corresponding to the above three solutions are in descending order: ceramic>glass>composite board, and they are all higher than the anti-interference degree of metal. However, among the prices of the mobile terminal backplane materials corresponding to the above three solutions, the price of ceramics is the highest, followed by glass, but it is still relatively high, and it is difficult to apply to low-end mobile terminals with a large market share. In response to the above technical problems, the inventor has conducted in-depth research and found that the backplane of the mobile terminal can be prepared by using non-metallic composite materials as raw materials, so that the mobile terminal has a high relative permittivity, strong anti-shielding ability, and can The electromagnetic signal or magnetic field can pass through the backplane of the mobile terminal more quickly, and the non-metallic composite material is easy to be processed and formed, with large toughness and damage tolerance, good impact resistance, good performance, long service life and relatively low cost. Low.

In view of this, in one aspect of the present invention, the present invention provides a mobile terminal backplane. According to an embodiment of the present invention, referring to FIG. 1 , the mobile terminal backplane includes: a thermally conductive layer 100 containing at least one of graphene or graphene oxide, and a thermoplastic resin; a protective layer 200 , the The protective layer 200 is disposed on one surface of the thermally conductive layer 100 , and the protective layer 100 contains diamond and the thermoplastic resin. The inventors found that the mobile terminal backplane has a simple structure, is easy to implement, has high yield, low cost, high toughness, high damage tolerance, high temperature resistance, good flame retardant performance, good impact resistance, and has a relatively low cost. High relative dielectric constant, strong anti-signal shielding ability, can well meet the technical requirements of 5G communication, adding graphene or graphene oxide to the thermal layer can improve the thermal conductivity and relative dielectric constant of the mobile terminal backplane , adding diamond in the protective layer makes the wear resistance and thermal conductivity of the mobile terminal backplane better, which is beneficial to improve the heating problem of the mobile terminal.

It should be noted that the protective layer is disposed on the surface of the thermal conductive layer away from the user during use, that is, the inner layer is a thermal conductive layer with thermal conductivity, and the outer layer is a protective layer with both thermal conductivity and wear resistance.

According to the embodiment of the present invention, the type of the thermoplastic resin is not particularly limited, as long as it can meet the requirements, those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the thermoplastic resin includes at least one of polycarbonate and polymethyl methacrylate. As a result, thermoplastic resins have a wide range of sources, do not contain harmful substances, meet RoHS requirements, have better mechanical properties, have high tensile strength and flame retardant strength, high toughness, impact resistance and damage tolerance, and are chemically stable. It has strong performance, long service life, high temperature resistance, good dimensional stability, easy processing and molding, and low cost.

In some embodiments of the present invention, the particle size of the diamond is 10 nanometers to 2 micrometers. In some specific embodiments of the present invention, the particle size of the diamond is 700-1000 nanometers. Therefore, the thermal expansion coefficient of the mobile terminal backplane containing the above-mentioned diamond particle size is small, and the thermal conductivity of the mobile terminal backplane increases with the increase of the diamond particle size within the above-mentioned particle size range, and the heat conduction effect is better, and then Improve the performance of the mobile terminal backplane. When the particle size of diamond is too large, the surface of the protective layer will not be fine enough, and if the particle size is too small, the diamond powder will be difficult to disperse in the system and easy to agglomerate.

It should be noted that the term "particle size" used herein refers to the median particle size (D50), specifically, refers to the particle size corresponding to the cumulative particle size distribution percentage of a sample reaching 50%.

According to an embodiment of the present invention, the thermally conductive layer and the protective layer further independently include at least one of the following: a ceramic powder; a flame retardant; and an auxiliary agent. Therefore, adding ceramic powder can improve the relative dielectric constant, thermal conductivity or anti-wear performance of the mobile terminal backplane, adding a flame retardant can improve the flame retardant performance of the mobile terminal backplane, and adding an auxiliary agent can make the mobile terminal backplane Easy to form and long service life. It should be noted that when the color of the protective layer is black, the protective layer may contain at least one of graphene or graphene oxide, and when the color of the protective layer is non-black, the protective layer may not contain graphene or Graphene oxide, thus, the protective layer is more beautiful and good-looking, and the consumer experience is improved.

According to the embodiment of the present invention, the type of ceramic powder is not particularly limited, as long as the requirements can be met, those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the ceramic powder includes at least one of alumina and zirconia. Thus, the thermal conductivity of the thermally conductive layer or the protective layer can be effectively improved, and the thermally conductive layer or the protective layer can have higher relative permittivity, hardness and wear resistance.

According to an embodiment of the present invention, the zirconia includes first zirconia particles and second zirconia particles, wherein the particle size of the first zirconia particles is 5-20 times the particle size of the second zirconia particles times, and the maximum particle size of the first zirconia particles is not greater than 30 microns. In some embodiments of the present invention, the particle size of the first zirconia particles is 20-30 microns, and the particle size of the second zirconia particles is 1-5 microns. Among them, the first zirconia particles play a major role in thermal conduction, and the second zirconia particles play a synergistic role in thermal conduction. The two particles are graded to achieve close opposite poles and have a good thermal conduction effect. Moreover, the particles contain the above two particle sizes. The dispersed zirconia is more uniform, easy to add, and easy to process, which can further improve the hardness, wear resistance and bending strength of the mobile terminal backplane. When the particle size of the zirconia particles is too large, the filling ratio is low, and the thermal conductivity effect is not good. When the particle size of the zirconia particles is too small, the gradation effect is difficult to achieve and the thermal conductivity effect is reduced.

In some embodiments of the present invention, in order to further improve the uniformity of the dispersion of zirconia particles and obtain a suitable relative permittivity, the mass ratio of the first zirconia particles to the second zirconia particles is 1:(0.5 -2). As a result, the zirconia particles are easier to disperse uniformly, and easier to add and process, and the mobile terminal backplane containing the above-mentioned zirconia particles has better hardness, wear resistance and bending strength. When the mass ratio of the first zirconia particles to the second zirconia particles is too large, the grading effect will be affected and the thermal conductivity effect will be reduced; when the mass ratio of the first zirconia particles to the second zirconia particles is too small, the subsequent products will be affected. Molding. In some specific embodiments of the present invention, the mass ratio of the first zirconia particles to the second zirconia particles is 1:1. Therefore, the zirconia particles are more uniformly dispersed, and the obtained mobile terminal backplane has better hardness, higher wear resistance and higher bending strength.

According to an embodiment of the present invention, the type of the alumina is α-type alumina. Therefore, the α-type alumina has better thermal conductivity, high electrical resistivity, and good insulating properties.

According to an embodiment of the present invention, the alumina includes first alumina particles and second alumina particles, wherein the particle size of the first alumina particles is 5-20 times the particle size of the second alumina particles times, and the maximum particle size of the first alumina particles is not greater than 30 microns. Among them, the first alumina particles play a major role in heat conduction, and the second alumina particles play a synergistic heat conduction role, and the two are graded to achieve close packing and have a good heat conduction effect. Alumina is easier to adjust the dielectric constant of the product and easier to process. In some embodiments of the present invention, the particle size of the first alumina particles is 20-30 microns, and the particle size of the second alumina particles is 1-5 microns. Therefore, the hardness, wear resistance, relative permittivity and thermal conductivity of the mobile terminal backplane having the alumina with the above particle size are better. When the particle size of the alumina particles is too large, the filling ratio is low and the thermal conductivity effect is reduced. When the particle size of the alumina particles is too small, the gradation effect is difficult to achieve and the thermal conductivity effect is reduced.

In some embodiments of the present invention, in order to further improve the dispersion uniformity of the alumina particles and obtain a suitable relative dielectric constant, the mass ratio of the first alumina particles to the second alumina particles is 1:( 0.5-2). Therefore, the mobile terminal backplane containing the above-mentioned alumina particle size has better hardness, wear resistance, relative permittivity and thermal conductivity. When the mass ratio of the first alumina particles to the second alumina particles is too large, the grading effect will be affected and the thermal conductivity effect will be reduced; when the mass ratio of the first alumina particles to the second alumina particles is too small, the subsequent products will be affected. Molding. In some specific embodiments of the present invention, the mass ratio of the first alumina particles to the second alumina particles is 1:1. Therefore, the mobile terminal backplane has better hardness, better thermal conductivity, higher wear resistance and bending strength, and higher relative permittivity.

In some embodiments of the present invention, in order to further improve the dispersion uniformity of the alumina particles, obtain a suitable dielectric constant, and improve the performance of the mobile terminal backplane, the shape of the first alumina particles is spherical or quasi-spherical , the shape of the second alumina particles is irregular. Among them, spherical alumina can reduce the viscosity of the system, easy to achieve high proportion filling, and improve thermal conductivity; irregular alumina, filled in the gap of spherical alumina, achieves close packing, and has better synergistic thermal conductivity. Therefore, the alumina having the above-mentioned shape can further improve the hardness, wear resistance, relative permittivity and thermal conductivity of the backplane of the mobile terminal.

According to the embodiments of the present invention, the composition of the auxiliary agent is not particularly limited, as long as it can meet the requirements, those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the adjuvant includes at least one of a coupling agent or an antiaging agent. Thereby, the molding of the thermally conductive layer or the protective layer is facilitated and the service life thereof can be prolonged.

It should be noted that the above-mentioned flame retardants, coupling agents or antioxidants are all common types in the plastics industry. For example, the flame retardant can be an organic flame retardant (including chlorine-based flame retardants, phosphorus-based flame retardants or bromine-based flame retardants, etc.) or inorganic flame retardants (including aluminum hydroxide or magnesium hydroxide, etc.) The flame retardant has better stability and better flame retardant effect; the coupling agent can be a silane coupling agent, etc., which can reduce the viscosity of the thermoplastic resin during processing and improve the dispersion of ceramic powder and other auxiliary agents to improve the Processability, so that the protective layer has good surface quality and mechanical, thermal and electrical properties; antioxidants can be hydrogen donors such as hindered phenols, secondary aromatic amines, tertiary amine electron donors, and quinones. Free radical capture It can effectively absorb ultraviolet rays, greatly improve the anti-aging performance of the product, and is non-flammable, non-corrosive, and has good storage stability.

According to the embodiment of the present invention, the composition of each component in the thermally conductive layer is not particularly limited, as long as the requirements can be met, those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the thermally conductive layer comprises: 5-50 parts by weight of thermoplastic resin, 1-10 parts by weight of at least one of graphene or graphene oxide, 10-40 parts by weight of zirconium oxide, and aluminum oxide 10-40 parts by weight, 5-15 parts by weight of flame retardant, 0.1-5 parts by weight of coupling agent, 0.1-5 parts by weight of anti-aging agent, wherein the content of the graphene in the thermally conductive layer is not more than 5% by weight . In some specific embodiments of the present invention, the thermally conductive layer comprises: 30-40 parts by weight of thermoplastic resin, 5-10 parts by weight of at least one of graphene or graphene oxide, 10-20 parts by weight of zirconium oxide, 30-40 parts by weight of aluminum, 5-15 parts by weight of flame retardant, 1-3 parts by weight of coupling agent, 1-3 parts by weight of anti-aging agent, wherein the content of the graphene in the thermal conductive layer is not more than 5wt %. Therefore, adding graphene or graphene oxide to the thermal conductive layer makes the thermal conductive layer have a relatively large relative permittivity, thereby making it have better anti-signal shielding performance, and each component in the thermal conductive layer is within the above-mentioned ratio range. The internal heat conduction effect is better, which can effectively improve the heating problem of the mobile terminal, and the performance is better; due to the electrical conductivity of graphene, if the amount of graphene added is too large, it will have an electromagnetic shielding effect and reduce the anti-signal shielding of the mobile terminal backplane. performance.

According to the embodiments of the present invention, the composition of each component in the protective layer is not particularly limited, as long as the requirements can be met, those skilled in the art can flexibly select according to actual needs. In some embodiments of the present invention, the protective layer includes: 5-50 parts by weight of thermoplastic resin, 1-15 parts by weight of diamond, 10-40 parts by weight of zirconia, 10-40 parts by weight of alumina, and 5 parts by weight of flame retardant ~15 parts by weight, 0.1-5 parts by weight of coupling agent, and 0.1-5 parts by weight of anti-aging agent. In some specific embodiments of the present invention, the protective layer comprises: 20-30 parts by weight of thermoplastic resin, 5-15 parts by weight of diamond, 10-30 parts by weight of zirconia, 20-40 parts by weight of alumina, and flame retardant 5-15 parts by weight, 1-3 parts by weight of coupling agent, and 1-5 parts by weight of anti-aging agent. Therefore, adding diamond into the protective layer can make the protective layer have strong wear resistance and better thermal conductivity, and the relative permittivity of each component in the protective layer within the above ratio range is large, and the resistance to Strong signal shielding ability, high hardness, high bending strength and good performance.

According to an embodiment of the present invention, in order to further improve the usability of the mobile terminal backplane, the thickness of the thermally conductive layer is 2-50 times the thickness of the protective layer. In some specific embodiments of the present invention, the thickness of the thermally conductive layer is 1-15 times the thickness of the protective layer. Therefore, the backplane of the mobile terminal has better thermal conductivity, which is beneficial to improve the heating problem of the mobile terminal, and at the same time, it can effectively protect the mobile terminal. When the thickness ratio of the thermal conductive layer to the protective layer is too small, the strength of the product is reduced or the cost is greatly increased; when the thickness ratio of the thermal conductive layer to the protective layer is too large, the product is too thick or the wear resistance is poor.

According to an embodiment of the present invention, the thickness of the thermally conductive layer is 100-800 microns, and the thickness of the protective layer is 5-100 microns. For example, the thickness of the thermally conductive layer can be 100 microns, 150 microns, 200 microns, 250 microns, 300 microns, 350 microns, 400 microns, 450 microns, 500 microns, 550 microns, 600 microns, 650 microns, 700 microns, 750 microns, 800 microns microns, etc., the thickness of the protective layer can be 5 microns, 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, 55 microns, 60 microns, 65 microns, 70 microns , 75 microns, 80 microns, 85 microns, 90 microns, 95 microns, 100 microns, etc. Therefore, the heat conduction performance of the backplane of the mobile terminal is better, which is beneficial to improve the heating problem of the mobile terminal, and at the same time, it can play a role of protecting the mobile terminal. When the thickness of the thermal conduction layer is too thin, the thermal conduction effect is poor and the performance is poor; when the thickness of the thermal conduction layer is too thick, the thickness of the backplane of the mobile terminal is increased, thereby increasing the size of the mobile terminal and the performance is poor; When the thickness of the protective layer is too thin, the protection effect is not good and the use performance is poor; when the thickness of the protective layer is too thick, the thickness of the backplane of the mobile terminal is increased, thereby increasing the size of the mobile terminal and the use performance is poor.

According to the embodiment of the present invention, the thickness of the mobile terminal backplane is not particularly limited, as long as it can meet the needs, those skilled in the art can flexibly choose according to actual needs. In some embodiments of the present invention, the thickness of the backplane of the mobile terminal may be 100 microns to 1 mm. Therefore, the thickness of the backplane of the mobile terminal within the above range has better performance and can effectively protect the mobile terminal from damage. If the thickness of the backplane of the mobile terminal is too thin, it cannot protect the mobile terminal, and if the thickness of the backplane of the mobile terminal is too thick, the size of the mobile terminal is large and the performance is poor.

According to the embodiment of the present invention, the shape of the mobile terminal backplane is not particularly limited, as long as it can meet the usage requirements, those skilled in the art can flexibly choose according to actual needs. For example, the backplane of the mobile terminal may have a 2-dimensional structure, a 2.5-dimensional structure, or a 3-dimensional structure, etc., thus, it can be used in a wide range, and can meet the consumption demands of consumers and improve the consumption experience of consumers.

In another aspect of the present invention, the present invention provides a mobile terminal. According to an embodiment of the present invention, the mobile terminal includes the aforementioned mobile terminal backplane. The mobile terminal has all the features and advantages of the aforementioned mobile terminal backplane, which will not be repeated here.

According to the embodiments of the present invention, the types of the above-mentioned mobile terminals are not particularly limited, and those skilled in the art can flexibly select them according to actual needs. For example, the types of the above-mentioned mobile terminals may include, but are not limited to, mobile phones, tablet computers, wearable devices, and the like. According to an embodiment of the present invention, the structure of the above-mentioned mobile terminal not only includes the aforementioned mobile terminal backplane, but also includes the structure that a conventional mobile terminal should have, such as a display panel, a control circuit, and a packaging structure, which are not omitted here. Too much elaboration.

In another aspect of the present invention, the present invention provides a method for preparing the aforementioned mobile terminal backplane. According to an embodiment of the present invention, referring to FIG. 2 , the method includes:

S100: Perform a first extrusion process on the raw material for forming the thermally conductive layer to obtain a first sheet.

According to the embodiment of the present invention, the raw material for forming the thermal conductive layer may include thermoplastic resin, graphene or graphene oxide, ceramic powder, flame retardant, auxiliary agent, and the thermoplastic resin, graphene or graphene oxide, ceramic powder The body, flame retardant and auxiliary agent are consistent with the previous description, and will not be repeated here.

According to an embodiment of the present invention, the first extrusion treatment can be carried out in a twin-screw extrusion and calendering equipment, and the specific operation steps can be as follows: put the raw materials for forming the thermal conductive layer into the twin-screw extrusion and calendering equipment, and the extrusion treatment temperature It is 215～280 ℃. Therefore, the operation is simple and convenient, and the realization is easy, and the first sheet material with better forming effect is obtained.

S200 : subjecting the raw material for forming the protective layer to a second extrusion process to obtain a second sheet.

According to the embodiment of the present invention, the raw material for forming the protective layer may include thermoplastic resin, diamond, ceramic powder, flame retardant, auxiliary agent, and the thermoplastic resin, diamond, ceramic powder, flame retardant, auxiliary agent and the aforementioned are consistent with the descriptions, and will not be repeated here.

According to an embodiment of the present invention, the second extrusion treatment can be performed in a twin-screw extrusion and calendering equipment, and the specific operation steps can be as follows: put the raw materials for forming the protective layer into the twin-screw extrusion and calendering equipment, and the extrusion treatment temperature It is 215～280 ℃. Therefore, the operation is simple and convenient, and the realization is easy, and the second sheet material with better forming effect is obtained.

S300: Perform thermocompression molding on the first sheet and the second sheet to obtain the mobile terminal backplane.

According to an embodiment of the present invention, the steps of the above-mentioned hot-press forming are described by taking the first sheet and the second sheet being hot-pressed to prepare a mobile terminal backplane as an example, and the steps may be: The one sheet and the second sheet are stacked and formed by hot pressing at 5-20 MPa, and the temperature of hot pressing is 250-300°C. Thus, the first sheet and the second sheet can be hot-pressed to form the backplane of the mobile terminal, which is simple and convenient to operate, easy to implement, and low in cost. According to the embodiments of the present invention, in order to meet the actual molding requirements, those skilled in the art can cut the first sheet or the second sheet into a suitable size to facilitate subsequent molding.

According to the embodiment of the present invention, the backplane of the mobile terminal is consistent with the previous description, and details are not repeated here.

The inventors found that the method is simple and convenient to operate, easy to implement, and has a high yield of the prepared mobile terminal backplane.

According to the embodiment of the present invention, in a general mobile terminal backplane, the raw material used is general metal, but the metal backplane has a shielding effect on electromagnetic signals and can prevent the transmission of magnetic fields, thereby limiting the rapid transmission of signals and thus limiting the 5G era. The development of wireless charging cannot be achieved at the same time. In the present invention, the inventor uses a relatively low-priced thermoplastic resin as the base material for forming the mobile terminal backplane, and adds materials that can improve the performance of the backplane into the base material, so that the final prepared mobile terminal backplane The relative permittivity of the board can reach 4 and above, with better anti-signal shielding performance, electromagnetic signals can be transmitted to the mobile terminal relatively quickly, the magnetic field can be transmitted, the performance is improved, and the thermal conductivity can reach 1.5W/ m·K and above, the thermal conductivity is better, the hardness can reach 8H, the bending strength is strong, the wear resistance is better, the flame retardant requirements and RoHS requirements are met, the price is low, and it can be used in the market Relatively large low-end mobile terminal.

Example

Example 1

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 600 microns, and the components are composed of: 20 parts by weight of polymethyl methacrylate, 6 parts by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two 1:1) 12 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 34 parts by weight, 10 parts by weight of flame retardant, even 1 part by weight of joint agent and 1 part by weight of anti-aging agent.

The protective layer:

The thickness is 50 microns, and the components are composed of: 25 parts by weight of polycarbonate, 10 parts by weight of diamond (with a particle size of 800 nanometers), and zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the two Mass ratio 1:1) 20 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 30 parts by weight, flame retardant 10 parts by weight , 2 parts by weight of coupling agent, and 3 parts by weight of anti-aging agent.

2) Preparation method:

1. Take each component that forms the thermal conductive layer, put it into the twin-screw extrusion calendering equipment to make the first sheet, and the operating temperature is 215℃;

2. Take each component that forms the protective layer, put it into the twin-screw extrusion calendering equipment to make the second sheet, and the operating temperature is 215 °C;

3. The first sheet and the second sheet are stacked, and hot-pressed at 5MPa, and the temperature is 250°C.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 20 yuan. It has been determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.3, the thermal conductivity is 1.9W/m·K, which meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 124MPa.

Example 2

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 100 microns, and the components are composed of: 50 parts by weight of polymethyl methacrylate, 8 parts by weight of graphene, zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, and the mass ratio of the two is 1 : 0.5) 40 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:0.5) 40 parts by weight, 15 parts by weight of flame retardant, coupled 5 parts by weight of anti-aging agent and 0.1 part by weight of anti-aging agent.

The protective layer:

The thickness is 5 microns, and the components are composed of: 50 parts by weight of polycarbonate, 15 parts by weight of diamond (particle size of 10 nanometers), zirconia (consisting of two particle sizes of 1 micron particle size and 20 micron particle size, both of which are Mass ratio 1:0.5) 40 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:0.5) 40 parts by weight, flame retardant 15 parts by weight , 5 parts by weight of coupling agent, and 0.1 part by weight of anti-aging agent.

2) Preparation method:

1. Take each component that forms the thermal conductive layer, put it into the twin-screw extrusion calendering equipment to make the first sheet, and the operating temperature is 280℃;

2. Take each component that forms the protective layer, put it into the twin-screw extrusion calendering equipment to make the second sheet, and the operating temperature is 280 °C;

3. The first sheet and the second sheet are stacked, and hot-pressed at 20 MPa at a temperature of 300 °C.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 12 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.0, the thermal conductivity is 1.45W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 132MPa.

Example 3

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 800 microns, and the composition is composed of: 5 parts by weight of polycarbonate, 1 part by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, and the mass ratio of the two is 1:2 ) 10 parts by weight, alumina (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the mass ratio of the two is 1:2) 10 parts by weight, 5 parts by weight of flame retardant, 0.1 of coupling agent parts by weight, 5 parts by weight of antioxidant.

The protective layer:

The thickness is 100 microns, and the components are composed of: 5 parts by weight of polymethyl methacrylate, 1 part by weight of diamond (particle size of 2 microns), zirconia (consisting of two particle sizes of 5 microns in particle size and 30 microns in particle size) , the mass ratio of the two is 1:2) 10 parts by weight, alumina (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the mass ratio of the two is 1:2) 10 parts by weight, flame retardant 5 parts by weight, 0.1 part by weight of coupling agent, and 5 parts by weight of antioxidant.

2) Preparation method:

1. Take each component that forms the thermal conductive layer, put it into the twin-screw extrusion calendering equipment to make the first sheet, and the operating temperature is 260 °C;

2. Take each component that forms the protective layer, put it into the twin-screw extrusion calendering equipment to make the second sheet, and the operating temperature is 260 °C;

3. The first sheet and the second sheet are stacked, and hot-pressed at 10 MPa at a temperature of 275°C.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 23 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.6, the thermal conductivity is 2.1W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 97MPa.

Example 4

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 600 microns, and the components are composed of: 30 parts by weight of polymethyl methacrylate, 6 parts by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two 1:1) 25 parts by weight, alumina (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two is 1:1) 25 parts by weight, 10 parts by weight of flame retardant, even 3 parts by weight of joint agent and 3 parts by weight of anti-aging agent.

The protective layer:

The thickness is 12 microns, and the components are composed of: 30 parts by weight of polymethyl methacrylate, 8 parts by weight of diamond (with a particle size of 90 nanometers), and zirconia (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns) , the mass ratio of the two is 1:1) 25 parts by weight, alumina (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two is 1:1) 25 parts by weight, flame retardant 10 parts by weight, 3 parts by weight of coupling agent, and 3 parts by weight of anti-aging agent.

2) The preparation method is the same as in Example 1

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 20 yuan. It has been determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.4, the thermal conductivity is 1.7W/m·K, which meets the requirements of flame retardant and RoHS, the hardness is greater than 7H, and it has wear resistance and bending resistance. The strength is 127MPa.

Example 5

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 600 microns, and the components are composed of: 20 parts by weight of polymethyl methacrylate, 6 parts by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the mass ratio of the two 1:1) 12 parts by weight, 10 parts by weight of flame retardant, 1 part by weight of coupling agent, and 1 part by weight of antioxidant.

The protective layer:

The thickness is 50 microns, and the components are composed of: 25 parts by weight of polycarbonate, 10 parts by weight of diamond (with a particle size of 100 nanometers), and zirconia (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the two Mass ratio 1:1) 20 parts by weight, 10 parts by weight of flame retardant, 2 parts by weight of coupling agent, and 3 parts by weight of antioxidant.

2) The preparation method is the same as that of Example 1.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 17 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 3.4, the thermal conductivity is 1.1W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 110MPa.

Example 6

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 600 microns, and the components are composed of: 20 parts by weight of polycarbonate, 4 parts by weight of graphene oxide, 2 parts by weight of graphene, and zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, two mass ratio of 1:1) 40 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 25 parts by weight, flame retardant 8 weight parts parts, 3 parts by weight of coupling agent, and 2 parts by weight of anti-aging agent.

The protective layer:

The thickness is 50 microns, and the ingredients are composed of: 25 parts by weight of polymethyl methacrylate, 10 parts by weight of diamond (with a particle size of 800 nanometers), and zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns) , the mass ratio of the two is 1:1) 20 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 18 parts by weight, flame retardant 10 parts by weight, 3 parts by weight of coupling agent, and 2 parts by weight of antioxidant.

2) The preparation method is the same as that of Example 1.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 25 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.5, the thermal conductivity is 2.2W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 113MPa.

Comparative Example 1

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 800 microns, and the components are composed of: 50 parts by weight of polymethyl methacrylate, 10 parts by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two 1:1) 20 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 20 parts by weight, 5 parts by weight of flame retardant, even 0.1 part by weight of joint agent and 1 part by weight of anti-aging agent.

The protective layer:

The thickness is 5 microns, and the components are composed of: 50 parts by weight of polycarbonate, 5 parts by weight of diamond (particle size of 2 microns), zirconia (consisting of two particle sizes of 1 micron particle size and 20 micron particle size, both of which are Mass ratio 1:1) 40 parts by weight, alumina (consisting of two particle sizes with a particle size of 1 micron and a particle size of 20 microns, the mass ratio of the two is 1:1) 40 parts by weight, flame retardant 5 parts by weight , 1 part by weight of coupling agent, and 0.1 part by weight of anti-aging agent.

2) The preparation method is the same as in Example 1

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 19 yuan. It has been determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 3.6, and the thermal conductivity is 1.2W/m·K, which meets the requirements of flame retardant and RoHS, the hardness is greater than 6H, the wear resistance is poor, and the bending resistance is poor. The flexural strength is 107MPa.

Comparative Example 2

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 600 microns, and the components are composed of: 5 parts by weight of polycarbonate, 1 part by weight of graphene, 5 parts by weight of flame retardant, 0.1 part by weight of coupling agent, and 1 part by weight of antioxidant.

The protective layer:

The thickness is 12 microns, and the components are composed of: 5 parts by weight of polycarbonate, 1 part by weight of diamond (with a particle size of 5 nanometers), 15 parts by weight of flame retardant, 1 part by weight of coupling agent, and 0.1 part by weight of anti-aging agent.

2) The preparation method is the same as in Example 1

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 22 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 3.4, the thermal conductivity is 0.8W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 7H, and it has wear resistance and bending resistance. The strength is 122MPa.

Comparative Example 3

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 800 microns, and the components are composed of: 50 parts by weight of polymethyl methacrylate, 5 parts by weight of graphene oxide, 20 parts by weight of zirconia (with a particle size of 1 micron), and 20 parts by weight of aluminum oxide (with a particle size of 1 micron), 10 parts by weight of flame retardant, 3 parts by weight of coupling agent, and 3 parts by weight of antioxidant.

The protective layer:

Thickness of 100 microns, composition: 50 parts by weight of polycarbonate, 5 parts by weight of diamond (particle size of 2 microns), 40 parts by weight of zirconia (particle size of 1 micron), and 40 parts by weight of alumina (particle size of 1 micron) 10 parts by weight of flame retardant, 3 parts by weight of coupling agent, and 3 parts by weight of antioxidant.

2) The preparation method is the same as in Example 1

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 19 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 3.7, and the thermal conductivity is 1.4. W/m·K, in line with flame retardant requirements and RoHS requirements, the hardness is greater than 7H, it has wear resistance, and the bending strength is 106MPa.

Comparative Example 4

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

The thickness is 100 microns, and the components are composed of: 30 parts by weight of polymethyl methacrylate, 6 parts by weight of graphene oxide, zirconia (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two 1:1) 25 parts by weight, alumina (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two is 1:1) 25 parts by weight, 10 parts by weight of flame retardant, even 3 parts by weight of joint agent and 3 parts by weight of anti-aging agent.

The protective layer:

The thickness is 5 microns, and the composition is composed of: 30 parts by weight of polymethyl methacrylate, 25 parts by weight of zirconia (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two is 1:1) , alumina (consisting of two particle sizes with a particle size of 3 microns and a particle size of 25 microns, the mass ratio of the two is 1:1) 25 parts by weight, 10 parts by weight of flame retardant, 3 parts by weight of coupling agent, anti- 3 parts by weight of the aging agent.

2) The preparation method is the same as in Example 1

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 14 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 3.8, and the thermal conductivity is 1.1. W/m·K, in line with flame retardant requirements and RoHS requirements, the hardness is greater than 6H, the wear resistance is poor, and the bending strength is 121MPa.

Comparative Example 5

1) The structure and composition of the mobile terminal backplane are as follows:

Thermal layer:

Thickness of 600 microns, composition: 20 parts by weight of polymethyl methacrylate, 12 parts by weight of zirconia (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the mass ratio of the two is 1:1) , 10 parts by weight of flame retardant, 1 part by weight of coupling agent, and 1 part by weight of antioxidant.

The protective layer:

The thickness is 50 microns, and the components are composed of: 25 parts by weight of polycarbonate, 10 parts by weight of diamond (with a particle size of 100 nanometers), and zirconia (consisting of two particle sizes with a particle size of 5 microns and a particle size of 30 microns, the two Mass ratio 1:1) 20 parts by weight, 10 parts by weight of flame retardant, 2 parts by weight of coupling agent, and 3 parts by weight of antioxidant.

2) The preparation method is the same as that of Example 1.

After calculation, the cost of the mobile phone backplane of a single 5.5-inch mobile phone prepared in this embodiment is less than 18 yuan. It is determined that the relative dielectric constant of the mobile phone backplane prepared in this example is 4.2, the thermal conductivity is 1.4W/m·K, meets the requirements of flame retardant and RoHS, the hardness is greater than 8H, and it has wear resistance and bending resistance. The strength is 109MPa.

In the description of the present invention, it should 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, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed 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, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (15)

1. A mobile terminal backplane, comprising:

the heat conduction layer contains at least one of graphene or graphene oxide and thermoplastic resin;

the protective layer is arranged on one surface of the heat conduction layer, diamond and the thermoplastic resin are contained in the protective layer, the thickness of the heat conduction layer is 2-50 times of that of the protective layer, the thickness of the heat conduction layer is 100-800 micrometers, the thickness of the protective layer is 5-100 micrometers, and the particle size of the diamond is 10 nanometers-2 micrometers;

the heat conductive layer includes: 5-50 parts of thermoplastic resin, 1-10 parts of at least one of graphene or graphene oxide, 10-40 parts of zirconium oxide, 10-40 parts of aluminum oxide, 5-15 parts of flame retardant, 0.1-5 parts of coupling agent and 0.1-5 parts of anti-aging agent, wherein the content of the graphene in the heat conduction layer is not more than 5 wt%;

the protective layer includes: 5-50 parts of thermoplastic resin, 1-15 parts of diamond, 10-40 parts of zirconia, 10-40 parts of alumina, 5-15 parts of flame retardant, 0.1-5 parts of coupling agent and 0.1-5 parts of anti-aging agent.

2. The mobile terminal backplate of claim 1, wherein the thermoplastic resin comprises at least one of polycarbonate and polymethyl methacrylate.

3. The backplate of claim 1, wherein the zirconia comprises first zirconia particles and second zirconia particles, wherein the first zirconia particles have a particle size 5-20 times the particle size of the second zirconia particles, and the maximum particle size of the first zirconia particles is not greater than 30 μm.

4. The backplate of claim 3, wherein the mass ratio of the first zirconia particles to the second zirconia particles is 1: (0.5-2).

5. The backplate for a mobile terminal according to claim 4, wherein the mass ratio of the first zirconia particles to the second zirconia particles is 1: 1.

6. the mobile terminal backplate of claim 1, wherein the alumina is alpha alumina.

7. The mobile terminal backplate of claim 1, wherein the alumina comprises first alumina particles and second alumina particles, wherein the first alumina particles have a particle size 5-20 times larger than the second alumina particles, and the maximum particle size of the first alumina particles is not greater than 30 μm.

8. The mobile terminal backplate of claim 7, wherein the first alumina particles are spherical or spheroidal in shape and the second alumina particles are irregular in shape.

9. The mobile terminal backplate of claim 7, wherein the mass ratio of the first alumina particles to the second alumina particles is 1: (0.5-2).

10. The mobile terminal backplate of claim 9, wherein the mass ratio of the first alumina particles to the second alumina particles is 1: 1.

11. the backplate for mobile terminal of claim 1, wherein the diamond has a particle size of 700 nm and 1000 nm.

12. A mobile terminal backplane according to any of claims 1-11, wherein said heat conducting layer comprises: 30-40 parts of thermoplastic resin, 5-10 parts of at least one of graphene or graphene oxide, 10-20 parts of zirconium oxide, 30-40 parts of aluminum oxide, 5-15 parts of flame retardant, 1-3 parts of coupling agent and 1-3 parts of anti-aging agent, wherein the content of the graphene in the heat conducting layer is not more than 5 wt%;

the protective layer includes: 5-50 parts of thermoplastic resin, 1-15 parts of diamond, 10-40 parts of zirconia, 10-40 parts of alumina, 5-15 parts of flame retardant, 0.1-5 parts of coupling agent and 0.1-5 parts of anti-aging agent.

13. A mobile terminal backplane according to any of claims 1-11, wherein said protective layer comprises: 20-30 parts of thermoplastic resin, 5-15 parts of diamond, 10-30 parts of zirconia, 20-40 parts of alumina, 5-15 parts of flame retardant, 1-3 parts of coupling agent and 1-5 parts of anti-aging agent.

14. A mobile terminal characterized by comprising a mobile terminal backplane according to any of claims 1-13.

15. A method for preparing the mobile terminal backplane according to any one of claims 1 to 13, comprising:

carrying out first extrusion treatment on the raw materials for forming the heat conduction layer to obtain a first sheet;

performing second extrusion treatment on the raw material for forming the protective layer to obtain a second sheet;

and carrying out hot press molding on the first sheet and the second sheet to obtain the mobile terminal backboard.

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