Protective rear cover and mobile terminal

Abstract

The utility model discloses a protective rear cover, which comprises an outer side substrate and an inner side substrate which are oppositely arranged, the first metal layer is arranged on the surface of one side, facing the inner side substrate, of the outer side substrate; the second metal layer is arranged on the surface of one side, facing the outer substrate, of the inner substrate; the outer side substrate and the inner side substrate are combined through the first metal layer and the second metal layer, and an intermetallic compound layer is formed on the combination interface of the first metal layer and the second metal layer. The protective rear cover has high protective performance. The utility model further discloses a mobile terminal which comprises the protective rear cover.

Description

Technical Field

[0001] The utility model relates to terminal protection technology, in particular to a protective back cover and a mobile terminal. Background Art

[0002] Mobile terminals such as mobile phones and tablets generally use glass materials as the back cover. Compared with the front cover, the prior art does not pay enough attention to the protection design of the back cover, and only simply uses tempered glass materials, which results in the protection performance of the back cover not meeting the requirements. Content of the Utility Model

[0003] In order to solve the above deficiencies of the prior art, the utility model provides a protective back cover with high protection performance.

[0004] The utility model also provides a mobile terminal including the above protective back cover.

[0005] The technical problems to be solved by the utility model are realized through the following technical solutions:

[0006] A protective back cover, comprising:

[0007] An outer substrate and an inner substrate arranged oppositely;

[0008] A first metal layer disposed on one surface of the outer substrate facing the inner substrate;

[0009] A second metal layer disposed on one surface of the inner substrate facing the outer substrate;

[0010] The outer substrate and the inner substrate are combined through the first metal layer and the second metal layer, and an intermetallic compound layer is formed at the bonding interface of the first metal layer and the second metal layer.

[0011] Further, one surface of the first metal layer facing the second metal layer is a first concave-convex microstructure, one surface of the second metal layer facing the first metal layer is a second concave-convex microstructure, and the first concave-convex microstructure and the second concave-convex microstructure are mutually embedded.

[0012] Further, the protruding height or the recessed depth of the first concave-convex microstructure and the second concave-convex microstructure is 1-3 μm.

[0013] Further, one of the first metal layer and the second metal layer is a single-element nickel layer or a nickel alloy layer.

[0014] Further, the other of the first metal layer and the second metal layer is a single-element gold layer, a single-element tin layer, a single-element silver layer, a single-element copper layer, a single-element bismuth layer, a single-element indium layer, or a metal alloy layer containing gold, tin, silver, copper, bismuth or indium.

[0015] Furthermore, the protective back cover further includes an appearance decoration layer, and the appearance decoration layer is disposed between the outer substrate and the first metal layer.

[0016] Furthermore, the protective back cover further includes an anti-reflection layer, and the anti-reflection layer is disposed on a surface of the outer substrate facing away from the inner substrate.

[0017] Furthermore, at least one of the outer substrate and the inner substrate is a glass substrate.

[0018] Furthermore, the glass substrate is tempered glass.

[0019] A mobile terminal includes the above-mentioned protective back cover.

[0020] The utility model has the following beneficial effects: The protective back cover of the utility model adopts a double-layer substrate structure, which can greatly improve the overall hardness of the back cover and improve the protective performance of the back cover. Moreover, the outer substrate and the inner substrate are combined through the first metal layer and the second metal layer, and the metal intermetallic compound layer will be formed at the interface after the combination of the first metal layer and the second metal layer. The metal intermetallic compound has a stable crystal structure, not only has extremely high hardness, but also can resist high temperature, and can further improve the overall hardness of the back cover and improve the protective performance of the back cover. Description of the Drawings

[0021] Figure 1 It is a schematic stacked structure diagram of the protective back cover of the utility model.

[0022] Figure 2 It is a separated schematic diagram of the mechanical inlay interlocking structure in the protective back cover of the utility model.

[0023] Figure 3 It is a schematic stacked structure diagram of another protective back cover of the utility model.

[0024] Figure 4 It is a schematic stacked structure diagram of yet another protective back cover of the utility model. Detailed Embodiments

[0025] The present utility model will be described in detail below with reference to the drawings and embodiments. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present utility model and should not be construed as a limitation to the present utility model.

[0026] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0027] In addition, the terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0028] In the present utility model, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", "setting", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0029] Embodiment 1

[0030] As Figure 1 shown, a protective back cover includes:

[0031] Outboard substrates 1 and inboard substrates 5 arranged oppositely;

[0032] A first metal layer 2 provided on one surface of the outboard substrate 1 facing the inboard substrate 5;

[0033] A second metal layer 4 provided on one surface of the inboard substrate 5 facing the outboard substrate 1;

[0034] The outboard substrate 1 and the inboard substrate 5 are combined through the first metal layer 2 and the second metal layer 4, and an intermetallic compound layer 3 is formed at the bonding interface of the first metal layer 2 and the second metal layer 4.

[0035] The protective back cover of the present utility model adopts a double-layer substrate structure, which can greatly improve the overall hardness of the back cover and improve the protective performance of the back cover. Moreover, the outer substrate 1 and the inner substrate 5 are combined through the first metal layer 2 and the second metal layer 4. After the first metal layer 2 and the second metal layer 4 are combined, the intermetallic compound layer 3 will be formed at the interface. The intermetallic compound has a stable crystal structure, not only has extremely high hardness, but also can resist high temperature, and can further improve the overall hardness of the back cover and improve the protective performance of the back cover.

[0036] The first metal layer 2 and the second metal layer 4 can be, but are not limited to, magnetron sputtering, vacuum evaporation, or vapor deposition and other methods to be respectively coated on the surfaces of the outer substrate 1 and the inner substrate 5 to form a film, and are combined through methods such as high-temperature welding.

[0037] However, considering that the high-temperature environment during metal welding will damage the outer substrate 1 and the inner substrate 5, preferably, as Figure 2 shown, the surface of the first metal layer 2 facing the second metal layer 4 is the first concave-convex microstructure 21, the surface of the second metal layer 4 facing the first metal layer 2 is the second concave-convex microstructure 41, and the first concave-convex microstructure 21 and the second concave-convex microstructure 41 are mutually embedded.

[0038] The protective back cover of the present utility model realizes the combination between the first metal layer 2 and the second metal layer 4 by respectively making the first concave-convex microstructure 21 and the second concave-convex microstructure 41 that can be mutually embedded on the surfaces of the first metal layer 2 and the second metal layer 4, and uses the mechanical inlay and interlock structure based on the micro-nano effect between the first concave-convex microstructure 21 and the second concave-convex microstructure 41, without high-temperature welding, and can avoid the outer substrate 1 and the inner substrate 5 from being damaged by high temperature.

[0039] The micro-nano effect refers to the strange or abnormal physical and chemical properties that micro-nano materials do not possess in traditional materials. These properties stem from the characteristics of micro-nano materials such as small size, large specific surface area, high surface energy, and large proportion of surface atoms. Mechanical inlay and interlock is a structural design method, usually used to enhance the bonding force and stability between materials. At the micro-nano scale, mechanical inlay and interlock enhance the bonding force by designing micro-nano structures with specific shapes so that these structures can form an interlocking relationship when they come into contact with each other.

[0040] In this embodiment, the protruding height or the recessed depth of the first concave-convex microstructure 21 and the second concave-convex microstructure 41 is 1-3 μm, and the thickness (including the concave-convex microstructure) of the first metal layer 2 and the second metal layer 4 is 5-10 μm.

[0041] Of course, in order to increase the thickness of the intermetallic compound, after the first metal layer 2 and the second metal layer 4 are mosaically interlocked through the first concavo-convex microstructure 21 and the second concavo-convex microstructure 41, baking can be further performed at a medium or low temperature, and the baking temperature is lower than the melting points of the first metal layer 2 and the second metal layer 4.

[0042] Preferably, one of the first metal layer 2 and the second metal layer 4 is a single-element nickel layer or a nickel alloy layer. Since metallic nickel is relatively easy to form an intermetallic compound with other metals, using a single-element nickel layer or a nickel alloy layer as the first metal layer 2 or the second metal layer 4 can increase the material selection range of the other metal layer.

[0043] The other of the first metal layer 2 and the second metal layer 4 is a single-element gold layer, a single-element tin layer, a single-element silver layer, a single-element copper layer, a single-element bismuth layer, a single-element indium layer, or a metal alloy layer containing gold, tin, silver, copper, bismuth, or indium.

[0044] In this embodiment, at least one of the outer substrate 1 and the inner substrate 5 is a glass substrate. Preferably, both the outer substrate 1 and the inner substrate 5 are glass covers, and most preferably, the glass substrate is tempered glass.

[0045] Embodiment 2

[0046] As an optimized solution of Embodiment 1, in this embodiment, as Figure 3 shown, the protective back cover further includes an appearance decoration layer 6, and the appearance decoration layer 6 is disposed between the outer substrate 1 and the first metal layer 2.

[0047] The appearance decoration layer 6 is used to provide a personalized appearance such as patterns, patterns, or colors for the protective back cover, and can be, but is not limited to, a silk-screen ink layer, a UV transfer layer, a PET film layer, or an interference coating layer.

[0048] Embodiment 3

[0049] As an optimized solution of Embodiment 1 or Embodiment 2, in this embodiment, as Figure 4 shown, the protective back cover further includes an anti-reflection layer 7, and the anti-reflection layer 7 is disposed on the surface of the outer substrate 1 facing away from the inner substrate 5.

[0050] The anti-reflection layer 7 is used to reduce the surface reflectivity of the protective back cover, so as to avoid problems such as glare and virtual images caused by a large amount of ambient light emission from the protective back cover. The anti-reflection layer 7 is formed by alternately laminating multiple high-refractive-index dielectric layers and multiple low-refractive-index dielectric layers. Due to the refractive index mutation between adjacent high-refractive-index dielectric layers and low-refractive-index dielectric layers, reflected light can be formed at the interface between the two. By reasonably designing the thicknesses of each high-refractive-index dielectric layer and each low-refractive-index dielectric layer, the optical path difference between two adjacent reflected lights satisfies 1 / 4 wavelength of visible light, so that optical interference can occur between two adjacent reflected lights and then cancel each other out, so as to achieve the purpose of eliminating the reflected light.

[0051] The high-refractive-index dielectric layer can be but is not limited to a titanium dioxide layer, a tungsten trioxide layer, a tantalum pentoxide layer or a zinc sulfide layer, and its thickness is 50-100 nm. The low-refractive-index dielectric layer can be but is not limited to a magnesium fluoride layer or a silicon dioxide layer, and its thickness is 80-250 nm.

[0052] Embodiment 4

[0053] A mobile terminal includes the protective back cover described in Embodiment 1, Embodiment 2 or Embodiment 3.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the embodiments of the present invention can still be modified or equivalently replaced, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective rear cover, characterized in that, Comprising: Relatively arranged outer substrate and inner substrate; A first metal layer disposed on one surface of the outer substrate facing the inner substrate; A second metal layer disposed on one surface of the inner substrate facing the outer substrate; The outer substrate and the inner substrate are combined through the first metal layer and the second metal layer, and an intermetallic compound layer is formed at the bonding interface of the first metal layer and the second metal layer.

2. The protective back cover according to claim 1, characterized in that, One surface of the first metal layer facing the second metal layer is a first concavo-convex microstructure, and one surface of the second metal layer facing the first metal layer is a second concavo-convex microstructure, and the first concavo-convex microstructure and the second concavo-convex microstructure are mutually embedded.

3. The protective back cover according to claim 2, characterized in that, The protruding height or the recessed depth of the first concavo-convex microstructure and the second concavo-convex microstructure is 1-3 μm.

4. The protective back cover according to claim 1, characterized in that, One of the first metal layer and the second metal layer is a single-element nickel layer or a nickel alloy layer.

5. The protective back cover according to claim 4, characterized in that, The other of the first metal layer and the second metal layer is a single-element gold layer, a single-element tin layer, a single-element silver layer, a single-element copper layer, a single-element bismuth layer, a single-element indium layer, or a metal alloy layer containing gold, tin, silver, copper, bismuth or indium.

6. The protective rear cover according to claim 1, characterized in that, The protective back cover further includes an appearance decorative layer, and the appearance decorative layer is disposed between the outer substrate and the first metal layer.

7. The protective rear cover according to claim 1, characterized in that, The protective back cover further includes an anti-reflection layer, and the anti-reflection layer is disposed on one surface of the outer substrate facing away from the inner substrate.

8. The protective rear cover according to claim 1, characterized in that, At least one of the outer substrate and the inner substrate is a glass substrate.

9. The protective back cover according to claim 8, characterized in that, The glass substrate is tempered glass.

10. A mobile terminal, characterized in that, Comprising the protective back cover according to claim 1.

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