Patterned bonded glass layers in electronic devices

#This relates generally to electronic devices, and, more particularly, to forming visually distinguishable regions in glass structures in electronic devices.

#Electronic devices such as cellular telephones, computers, watches, and other devices may contain glass structures. For example, electronic devices may have displays in which an array of pixels is covered with a transparent layer of glass. In some devices, a rear housing wall may be covered with a layer of glass. A decorative layer may be applied to the layer of glass to help improve the appearance of the rear housing wall.

#An electronic device may include electrical components and other components mounted within an interior of a housing. The device may have a display on a front face of the device and may have a glass housing wall on an opposing rear face of the device. The glass housing wall may be provided with regions having different appearances. The regions may be textured, may have coatings such as thin-film interference filter coatings formed from stacks of dielectric material having alternating indices of refraction, may have metal coating layers, and/or may have ink coating layers.

#FIG. 1 is a perspective view of an illustrative electronic device in accordance with an embodiment.

#FIG. 2 is a cross-sectional side view of an illustrative electronic device in accordance with an embodiment.

#FIG. 3 is a rear view of an illustrative electronic device in accordance with an embodiment.

#Electronic devices and other items may be provided with structures that are formed from transparent materials. For example, an electronic device may include a display. The display may have an array of pixels for displaying images for a user. To protect the pixel array from damage, the display may be covered with a layer of transparent material that serves as a display cover layer. The transparent material may be ceramic, polymer, crystalline material such as sapphire, or other suitable transparent material. Configurations in which such layers are formed from glass are sometimes described herein as an example. Portions of electronic devices such as optical windows, buttons, housing walls (e.g., rear housing walls and/or sidewalls), and other structures other than display cover layers may also be formed from ceramic, polymer, crystalline material such as sapphire, and/or glass and may be clear or may be colored. For example, the rear face of an electronic device may be covered with a layer of glass that forms a rear housing wall.

#It may be desirable to locally and/or globally modify the appearance of a layer of glass (or other layer of material) in an electronic device. For example, it may be desirable to create attractive trim around a display, around the periphery of a camera window or button, or other suitable location. In some arrangements it may be desirable to selectively modify the appearance of a glass layer or other structure to form text, graphical patterns such as icons, logos, and/or other patterns visible to a user.

#When creating structures such as these, there is a potential for unattractive features to develop on the glass layer. For example, if care is not taken, undesired shadowing may occur or surfaces may appear to sparkle excessively.