Patent Publication Number: US-2018042131-A1

Title: Glass housing and electronic device having the same

Description:
RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to Chinese Patent Application No. 201610629013.4, filed on Aug. 3, 2016. The entire content of which is incorporated herein in its entirety. 
     FIELD OF THE INVENTION 
     The present disclosure relates to electronic components, and more particularly relates to a glass housing and an electronic device having the glass housing. 
     BACKGROUND OF THE INVENTION 
     With the popularity of electronic devices such as smart phones and watches which are provided with a touch screen, various manufacturers compete to release differentiated products to attract consumers. A highlight design emerging in current market is to design a housing of the electronic device to be a curved surface. The electronic device with the curved surface can better fit the hand of the user, thus improving the comfort of holding and handling. If the housing of the watch is designed to be a curved surface, it can also better fit the wrist of the user, thus improving the comfort of wearing. In addition, a displaying housing with the curved surface can make the displaying content have more stereoscopic effect, the appearance can thereby be improved. The electronic device becomes more popular using glass as a material of the housing due to its better texture. However, the glass housing of the electronic device, especially with the curved surface, is susceptible to cracking due to accidental fall. 
     SUMMARY 
     Therefore, it is necessary to provide a glass housing capable of dispersing stress and enhancing strength, and an electronic device having the glass housing. 
     A glass housing includes an inner surface; an outer surface opposite to the inner surface; and a circumferential surface interconnecting the outer surface and the inner surface, wherein a distance between the inner surface and the outer surface ranges from 0.2 mm to 1.0 mm, the inner surface and the outer surface have central axes, the inner surface is bent to one side with respect to the central axis of the inner surface as a center to form an arcuate inner curved surface, the outer surface is bent to the same side with respect to the central axis of the outer surface as a center to form an arcuate outer curved surface, the inner curved surface and the outer curved surface have radii of curvature of 50 mm to 1000 mm, the glass housing has a height of 0.5 mm to 5 mm. 
     An electronic device is provided including the aforementioned glass housing. 
     By the configuration of the structural parameters, the aforementioned glass housing can disperse the concentrated stress, enhance the integral strength and reduce the risk that cracks emerge easily by a slight collision due to the concentrated stress. 
     The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings: 
         FIG. 1  is a front view of a glass housing according to an embodiment; 
         FIG. 2  is a cross-sectional view taken along line A-A of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along line B-B of  FIG. 1 ; and 
         FIG. 4  is a perspective view of an electronic device according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiments of the invention are described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The various embodiments of the invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     As shown in  FIG. 1  to  FIG. 3 , a glass housing  100  according to an embodiment can be applied to electronic devices such as smart phones or the like, and it can serve as a displaying housing and a back cover plate of phones or the like. 
     The glass housing  100  includes an inner surface  101 , an outer surface  102  opposite to the inner surface  101 , and a circumferential surface  109  interconnecting the outer surface  102  and the inner surface  101 . 
     A distance between the inner surface  101  and the outer surface  102  ranges from 0.2 mm to 1.0 mm, i.e. the glass housing  100  has a thickness of 0.2 mm to 1.0 mm. 
     The inner surface  101  has a central axis  103 , and the inner surface  101  is symmetrical about the central axis  103 . The outer surface  102  also has a central axis  104 , and the outer surface  102  is symmetrical about the central axis  104 . 
     The inner surface  101  is bent to one side with respect to the central axis  103  as a center to form an arcuate inner curved surface, the outer surface  102  is bent to the same side with respect to the central axis  104  as a center to form an arcuate outer curved surface. The inner curved surface and the outer curved surface have radii R of curvature of 50 mm to 1000 mm. 
     In some embodiments, radii R of curvature of the inner curved surface and the outer curved surface are the same, i.e., the glass housing  100  has a uniform thickness, such that the stress concentration can be eliminated and the integral strength of the glass housing  100  can be enhanced. 
     The glass housing  100  has a height H of 0.5 mm to 5 mm. The height H refers to a distance between a plane where two parallel edge lines  105 ,  106  of the inner surface  101  is located and the central axis  104  of the outer surface  102 . 
     By the configuration of the aforementioned structural parameters, the concentrated stress applied to the glass housing  100  is dispersed, thus an integral strength of the glass housing  100  is enhanced. The risk that cracks emerge easily by a slight collision due to the concentrated stress is reduced. 
     In the cross-section of the glass housing  100  shown in  FIG. 3 , an angle C formed by two connection lines between each end of the inner surface  101  and a center of an arc located by the inner surface  101 , i.e. a central angle C subtended by the arc ranges from 60° to 180°. A central angle C subtended by an arc located by the outer surface  102  also ranges from 60° to 180°. 
     In some embodiments, as shown in  FIG. 1 , an orthographic proj ection of the glass housing  100  is shaped as a rectangular with rounded corners. The rectangular orthographic projection has a length L of 50 mm to 500 mm, and a width W of 30 mm to 300 mm. 
     In some embodiments, the glass housing  100  further defines a first mounting hole  107  and a second mounting hole  108  penetrating the inner surface  101  and the outer surface  102 . Orthographic projections of centers of the first mounting hole  107  and the second mounting hole  108  fall on the central axis  103 ,  104 . The first and the second mounting holes  107 ,  108  are circular, and a diameter of the first mounting hole  107  is greater than a diameter of the second mounting hole  108 . In the particular application, the first mounting hole  107  can serve as a viewfinder hole for a camera, the second mounting hole  108  can be used to accommodate an infrared sensor. 
     In some embodiments, at least one of the inner surface  101  and the outer surface  102  is provided with a decorative layer. The decorative layer can color the glass housing  100  to provide a more appealing appearance. The decorative layer can be formed on the inner surface  101  and/or the outer surface  102  by ink printing or adhering. When the decorative layer is formed by ink printing, the decorative layer has a thickness of 5 μm to 40 μm. When the decorative layer is formed by adhering a decorative film, the decorative film has a thickness of 10 μm to 125 μm. The decorative film can be formed by screen printing an explosion-proof membrane with a substrate, and it can also be formed by directly screen printing an adhesive without a substrate. 
     During a manufacturing process of the glass housing  100 , at least one of the inner surface  101  and the outer surface  102  can be subjected to a strengthening treatment, such that the inner surface  101  and/or the outer surface  102  is provided with a surface compressive stress layer. In general, during the machining process of the glass, edges of the glass surface will inevitably generate micro-cracks, which can seriously reduce the strength of the glass. Although a size of the micro-crack can be decreased by physical machining processes such as polishing, further chemical strengthening treatment can achieve a better effect. For example, under a certain temperature, the glass can be immersed into a molten salt, the alkali metal ions in the glass and the alkali metal ions in the molten salt are interchanged by diffusion, thereby the surface compressive stress layer having a certain thickness is formed on the glass surface. The surface compressive stress layer is not an additional layered structure adhering to the glass surface, but is a strengthening layer formed inwardly from the glass surface with a certain thickness. The surface compressive stress layer makes the micro-crack not easy to be extended, thereby enhancing the strength of the glass. 
     In some embodiments, by the first strengthening treatment, the obtained surface compressive stress layer has a thickness of 50 μm to 100 μm. The surface compressive stress layer has a compressive stress of 200 MPa to 300 MPa. A central tensional stress between the inner surface  101  and the outer surface  102  is less than or equal to 100 MPa. 
     In some embodiments, by the second strengthening treatment, the obtained surface compressive stress layer has a thickness of 60 μm to 69 μm, i.e. a depth of the ion exchange in the second strengthening treatment process is less than that in the first strengthening treatment process. The surface compressive stress layer has a compressive stress of 710 MPa to 850 MPa. A central tensional stress between the inner surface  101  and the outer surface  102  is less than or equal to 160 MPa. By multiple strengthening treatment, the surface compressive stress can be improved, and the strength of the glass housing  100  is thereby improved. However, the central tensional stress is increased accompanying with an improvement of the surface compressive stress. The excessive central tensional stress will crack the glass from the inside out, thus the central tensional stress should be controlled, i.e. the surface compressive stress cannot be increased indefinitely. 
     In some embodiments, at least one of the inner surface  101  and the outer surface  102  is further attached with an anti-reflection layer. The anti-reflection layer can be formed by evaporation, sputtering or the like. 
     In some embodiments, the outer surface  102  is further attached with an anti-fingerprint layer. An initial water droplet angle of the anti-finger printer layer is greater than or equal to 110°. The so-called water droplet angle is an angle formed by the intersection of solid-liquid interface and gas-liquid interface, which is located at the solid-liquid-gas three phases interfaces. The greater the water droplet angle, the better the hydrophobicity and anti-fouling performance of the anti-fingerprint layer. The initial water droplet angle is the water droplet angle measured in the absence of the use and destruction of the formed anti-fingerprint layer. As the time of formation of the anti-fingerprint layer is prolonged and the wearing degree is increased, the water droplet will decrease. 
     As shown in  FIG. 4 , an electronic device  200  according to an embodiment includes the aforementioned glass housing  100 . The electronic device  200  is a smart phone. In some embodiments, the electronic device  200  can also be a tablet computer or the like. 
     Although the respective embodiments have been described one by one, it shall be appreciated that the respective embodiments will not be isolated. Those skilled in the art can apparently appreciate upon reading the disclosure of this application that the respective technical features involved in the respective embodiments can be combined arbitrarily between the respective embodiments as long as they have no collision with each other. Of course, the respective technical features mentioned in the same embodiment can also be combined arbitrarily as long as they have no collision with each other. 
     The foregoing descriptions are merely specific embodiments of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.