PATENT DOCUMENT

Publication Number: US-10639746-B1
Application Number: US-201514630230-A
Country: US
Kind Code: B1

Title: Ceramic-based components having laser-etched markings

Abstract:
A ceramic-based component including laser-etched markings, an electronic device including a ceramic-based component, and methods of forming the same. The ceramic-based component may include an outer surface, and a laser-etched marking formed on the outer surface. The laser-etched marking may include a recess having a substantially uneven surface formed in the outer surface. The recess may have a material composition distinct from a material composition of the outer surface. The method of forming the ceramic-based component may include laser etching an outer surface of a ceramic-based component, and in response to the laser etching, forming a laser-etched marking on the outer surface of the ceramic-based component. The method may also include altering the optically reflective properties of the laser-etched marking and/or altering a material composition of the laser-etched marking relative to a distinct material composition of the outer surface of the ceramic-based component.

Claims:
We claim: 
     
       1. A ceramic-based housing for an electronic device, comprising:
 a component formed from a ceramic material and defining an outer surface, the ceramic material comprising a first ratio of zirconium to aluminum; 
 a laser-etched blind recess formed into the component by ablating the ceramic material and defining at least a portion of a glyph; and 
 a marking defined by a bottom surface of the laser-etched blind recess and a raised portion extending above the outer surface and surrounding the laser-etched blind recess, the marking having an altered material composition of the ceramic material resulting from a melting and resolidification of the ceramic material, the marking having a second ratio of zirconium to aluminum, the second ratio different from the first ratio, and being optically distinct from a portion of the outer surface adjacent the marking, wherein 
 the portion of the outer surface of the ceramic material adjacent the marking is defined by an unaltered material composition of the ceramic material. 
 
     
     
       2. The ceramic-based housing of  claim 1 , wherein the outer surface comprises a first color that is one of black or white. 
     
     
       3. The ceramic-based housing of  claim 2 , wherein the laser-etched blind recess comprises a second color that is one of black or white, distinct from the first color. 
     
     
       4. The ceramic-based housing of  claim 1 , further comprising a heat affected region positioned adjacent to the laser-etched blind recess, the heat affected region positioned below the outer surface. 
     
     
       5. A ceramic-based housing for an electronic device, comprising:
 a ceramic component defining:
 an exterior surface comprising a first ceramic material having a first group of constituent material elements including zirconium and aluminum in a first ratio to one another; 
 a blind recess within the ceramic component; and 
 a marking defined by a surface of the blind recess and a raised feature surrounding the blind recess, the marking:
 comprising a second ceramic material having a second group of constituent material elements including zirconium and aluminum in a second ratio to one another, the second ratio different from the first ratio; 
 formed from a resolidified portion of the second ceramic material that is melted when the ceramic component is ablated; 
 exhibiting an optical contrast with respect to the exterior surface; and 
 defining at least a portion of a glyph. 
 
 
 
     
     
       6. The ceramic-based housing of  claim 5 , wherein the surface of the blind recess is an uneven surface that non-uniformly reflects incident light. 
     
     
       7. The ceramic-based housing of  claim 5 , wherein the surface of the blind recess has a different color than the exterior surface. 
     
     
       8. The ceramic-based housing of  claim 5 , wherein the exterior surface is at least partially formed via an annealing process that reflows a portion of the exterior surface to form a planar, polished first surface. 
     
     
       9. The ceramic-based housing of  claim 5 , further comprising a reflective coating on at least one of the exterior surface or the surface of the blind recess. 
     
     
       10. An electronic device, comprising:
 a housing component having a first ceramic composition having a first ratio of zirconium to aluminum, the housing component defining:
 a surface; and 
 a marking defined by:
 a laser-ablated groove formed into the housing component along the surface; and 
 a raised rim surrounding the laser-ablated groove, the raised rim and a surface of the laser-ablated groove formed of a second ceramic composition formed as a result of the laser ablation, the second ceramic composition having a second ratio of zirconium to aluminum, the second ratio different than the first ratio, 
 
 
 wherein the marking defines an exterior surface of the housing component that is optically contrasting with respect to a remainder of the surface having the first ceramic composition; and 
 a display at least partially positioned within the housing component. 
 
     
     
       11. The electronic device of  claim 10 , wherein the optical contrast is due, at least in part, to the second ceramic composition having a different ratio of zirconium to aluminum. 
     
     
       12. The electronic device of  claim 10 , wherein the optical contrast is due, at least in part, to a non-uniformity of the marking. 
     
     
       13. The ceramic-based housing of  claim 1 , wherein the laser-etched blind recess extends into the outer surface by less than 8 microns. 
     
     
       14. The ceramic-based housing of  claim 1 , wherein:
 the ceramic material is zirconia alumina. 
 
     
     
       15. The electronic device of  claim 10 , wherein:
 the first ceramic composition corresponds to a zirconia alumina ceramic; and 
 the second ceramic composition corresponds to a zirconia ceramic. 
 
     
     
       16. The ceramic-based housing of  claim 4 , wherein the heat affected region is positioned below the outer surface by a distance between approximately 5 microns and approximately 14 microns. 
     
     
       17. The ceramic-based housing of  claim 5 , wherein the ablating is performed with a laser having an ultraviolet wavelength. 
     
     
       18. The electronic device of  claim 10 , wherein the laser-ablated groove is formed by a laser having operational parameters comprising:
 a laser wavelength of 355 nm; and 
 a pulse width of 20 ns. 
 
     
     
       19. The electronic device of  claim 10 , wherein a height of the raised rim surrounding the laser-ablated groove above the surface is between approximately 1.4 microns and approximately 2.5 microns. 
     
     
       20. The ceramic-based housing of  claim 5 , wherein:
 a depth of the blind recess below the exterior surface of the ceramic component is between 2 microns and 8 microns; and 
 a height of the raised feature above the exterior surface of the ceramic component is between 1.4 microns and 2.5 microns.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a nonprovisional patent application and claims the benefit of U.S. Provisional Patent Application No. 62/015,098, filed Jun. 20, 2014 and titled “Ceramic-Based Components Having Laser Etched Markings,” the disclosure of which is hereby incorporated herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to a component for an electronic device, and more particularly, to a ceramic-based component including laser-etched markings, and methods of forming the ceramic-based component including laser-etched markings. 
     BACKGROUND 
     Conventional electronic devices typically include housings made from durable materials to protect the electronic device. It is desired to form these housings from materials that may withstand the everyday wear-and-tear applied to the electronic device. That is, the housing may be formed from a material that may withstand constant handling of the electronic device by a user, the transportation and/or packing of the electronic devices and undesired blunt forces (e.g., dropping, sitting on) applied to the electronic device during use. In conventional electronic devices, the housing may be formed from metals (e.g., aluminum), reinforced glass, and/or polymers (e.g., plastic, rubber). 
     Ceramic-based materials are typically not used to form housings for electronic devices. As a result of the physical and/or chemical properties of ceramic-based materials, certain manufacturing processes used to form an electronic device housing may be difficult and/or expensive to perform on ceramic-based material. For example, housings for electronic devices typically include designs, text or logos formed right on or in the material forming the housing. The designs, text or logos may be painted directly on a surface of the housing, or an etch may first be made on the surface, and then the etch may be subsequently painted. 
     When painting the designs on a ceramic-based material, the finished painted component needs to be “fired” or heated, to set the paint into the material. The process of heating the entire component formed from the ceramic-based material may substantially alter and/or undesirably change the physical and/or chemical properties of the ceramic-based material. In addition, the process of painting a design on a surface of a component formed from any material, ceramic-based or not, may require additional processing, such as, the application of a protective coating to avoid chipping or wearing away of the paint. The application of the protective coating over the painted surface may increase manufacturing time and/or cost of producing an electronic device housing. 
     With respect to etching ceramic-based material, conventional etching processes performed on the surface of ceramic-based material may be difficult and/or expensive to complete, because of the physical and/or chemical properties of the ceramic-based material. More specifically, due to the hardness, elasticity, fracture toughness and/or ductility of ceramic-based materials, conventional etching processes may produce insufficient or undesirable results when forming the designs on the surface of the ceramic-based materials. For example, the etch formed in the ceramic-based material using conventional etching processes may be substantially minimal or negligible, such that the etch may not be deep enough in the surface to be adequately painted. Where the etch is not capable of being painted due to the inadequate depth of the etch, the paint applied to the surface etch, protected by a protective coating or not, may wear off or fade over the life of the electronic device. 
     SUMMARY 
     Generally, embodiments discussed herein are related to a ceramic-based component including laser-etched markings, an electronic device including a ceramic-based component, and methods of forming the ceramic-based component including laser-etched markings. Ceramic-based components for an electronic device may include a laser-etched marking formed on an outer surface of the ceramic-based component. The process of laser etching the marking on the outer surface of the ceramic-based component may result in the formation of a recess in the ceramic-based component and, a contrast in colors between the outer surface and the laser-etched marking or recess. More specifically, the process of ablating and melting a portion of the ceramic-based component during a laser etching process may result in a color contrast, or other optical contrast, between the laser-etched portion (e.g., marking or recess) and the unaffected, outer surface of the ceramic-based component. The color/optical contrast may be formed as a result of the way light interacts with and/or reflects from the outer surface of the ceramic-based component, in contrast to the uneven, laser-etched marking or recess formed in the ceramic-based component. By forming a color contrast between the outer surface and the marking or recess formed on the surface of the ceramic-based component, the need for painting a design, text or logo on the component may be unnecessary. As such, the manufacturing time and/or cost of forming a ceramic-based component for an electronic device may be reduced. Furthermore, the marking formed on the surface of the ceramic-based component may be substantially permanent, and may not wear off, distort and/or fade over the life of the electronic device. 
     One embodiment may include a ceramic-based component. The ceramic-based component may include an outer surface, and a laser-etched marking formed on the outer surface. The laser-etched marking may comprise a recess having a substantially uneven surface formed in the outer surface. The recess may include a material composition distinct from a material composition of the outer surface. 
     Another embodiment may include an electronic device. The electronic device may include a housing having at least one outer surface. The electronic device may also include a laser-etched marking formed in the outer surface of the housing. The marking may comprise a material composition distinct from a material composition of the outer surface. Additionally, the electronic device may include a heat affected region positioned adjacent to the laser-etched marking. The heat affected region may be positioned below the outer surface of the housing. 
     A further embodiment may include a method of forming a ceramic-based component. The method may include laser etching an outer surface of a ceramic-based component, and in response to the laser etching, forming a laser-etched marking on the outer surface of the ceramic-based component. The method may also include altering the optically reflective properties of the laser-etched marking and/or altering a material composition of the laser-etched marking relative to a distinct material composition of the outer surface of the ceramic-based component. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1A  depicts a front view of an electronic device including a ceramic-based housing, according to embodiments. 
         FIG. 1B  depicts a back view of an electronic device including the ceramic-based housing, according to embodiments. 
         FIGS. 2-5  depict enlarged cross-section views of the ceramic-based housing of  FIG. 1B  taken along line  2 - 2 , according to various embodiments. 
         FIG. 6  depicts a flow chart of an example process for forming a ceramic-based component of an electronic device, according to embodiments. 
     
    
    
     It is noted that the drawings of the invention are not necessarily to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The following disclosure relates generally to a component for an electronic device, and more particularly, to a ceramic-based component including laser-etched markings, and methods of forming the ceramic-based component including laser-etched markings. 
     The ceramic-based component for an electronic device may include a laser-etched marking formed on an outer surface of the ceramic-based component. The process of laser etching the marking on the outer surface of the ceramic-based component may result in the formation of a recess in the ceramic-based component and, a contrast in colors between the outer surface and the laser-etched marking or recess. More specifically, the process of ablating and melting a portion of the ceramic-based component during a laser etching process may result in a color/optical contrast between the laser-etched portion (e.g., marking or recess) and the unaffected, outer surface of the ceramic-based component. The color/optical contrast may be formed as a result of the way light interacts with and/or reflects from the outer surface of the ceramic-based component, in contrast to the uneven, laser-etched marking or recess formed in the ceramic-based component. By forming a color contrast between the outer surface and the marking or recess formed on the surface of the ceramic-based component, the need for painting a design, text or logo on the component may be unnecessary. As such, the manufacturing time and/or cost of forming a ceramic-based component for an electronic device may be reduced. Furthermore, the marking formed on the surface of the ceramic-based component may be substantially permanent, and may not wear off, distort and/or fade over the life of the electronic device. 
     These and other embodiments are discussed below with reference to  FIGS. 1A-6 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1A  depicts an illustrative front view of one example of an electronic device  100 , according to embodiments. In the illustrated embodiment, electronic device  100  is implemented as a smart telephone. Other embodiments can implement electronic device  100  differently, such as, for example, as a laptop or desktop computer, a tablet computing device, a gaming device, a display, a digital music player, a wearable computing device or display, a health monitoring device, and so on. 
     Electronic device  100  includes a housing  102  at least partially surrounding a display  104  and one or more buttons  106  or input devices. More specifically, as shown in  FIG. 1A , electronic device  100  may include display  104  and button  106  formed on an outer surface  108  of housing  102 . Housing  102  can form outer surface  108  or partial outer surface  108  and protective case for the internal components of the electronic device  100 , and may at least partially surround display  104 . As discussed herein, outer surface  108  of housing  102  may include a substantially polished outer surface for housing  102 . Outer surface  108  may be polished using any suitable polishing technique for a component (e.g., housing  102 ) formed from a ceramic-based material. 
     Housing  102  can be formed of one or more components operably connected together, such as a front piece and a back piece. Alternatively, housing  102  can be formed of a single piece operably connected to display  104 . As discussed herein, housing  102  may be formed from a ceramic-based material including, but not limited to: zirconium dioxide (ZrO 2 ), commonly referred to as zirconia, and zirconia alumina (ZrO 2 Al 2 O 3 ), commonly referred to as zirconia toughened alumina (ZTA). 
     Display  104  can be implemented with any suitable technology, including, but not limited to, a multi-touch sensing touchscreen that uses liquid crystal display (LCD) technology, light emitting diode (LED) technology, organic light-emitting display (OLED) technology, organic electroluminescence (OEL) technology, or another type of display technology. Button  106  can take the form of a home button, which may be a mechanical button, a soft button (e.g., a button that does not physically move but still accepts inputs), an icon or image on a display, and so on. Further, in some embodiments, button  106  can be integrated as part of a cover glass of electronic device  100 . 
       FIG. 1B  depicts an illustrative back view of electronic device  100  of  FIG. 1A , according to embodiments. Outer surface  108  of the back of electronic device  100  may include a plurality of markings  110 . As shown in  FIG. 1B , markings  110  may include a variety of glyphs. More specifically, markings  110  may include letters, numbers and/or logos formed on outer surface  108  of electronic device  100 . Markings  110  may be formed on outer surface  108  of electronic device  100  to provide information relating to electronic device  100  to a user. In non-limiting examples as shown in  FIG. 1B , marking  110  formed on outer surface  108  may include the logo for the electronic device  100 , and/or marking  110  may include electronic device&#39;s  100  product identification or serial number. Additionally, marking  110  may include any other suitable logo, picture, graphic, decoration, pattern, product description or any other symbol or text (all of which are examples of markings) that may be included on electronic device  100 . As discussed herein, marking  110  may be laser-etched directly into or on outer surface  108  of electronic device  100 , to provide a color and/or optical contrast with outer surface  108 , such that a user of electronic device  100  may clearly see markings  110 . 
     Turning to  FIG. 2 , a cross-section view of electronic device  100  of  FIG. 1B  taken along line  2 - 2 , is shown according to embodiments. Specifically,  FIG. 2  shows an enlarged cross-section view of housing  102  of electronic device  100  including a portion of marking  110  formed in outer surface  108 . As discussed herein, housing  102  of electronic device  100  may be formed from a ceramic-based material. In an non-limiting example, housing  102  may be formed from zirconia alumina. 
     Housing  102 , and specifically, outer surface  108  of housing  102  may include a first color. More specifically, when viewed by a user of electronic device  100 , outer surface  108  of housing  102  may include a first color based on the chemical composition of the ceramic-based material forming housing  102 . The first color of housing  102  may not be a result of paint applied to outer surface  108 . In a non-limiting example, the first color of outer surface  108  may not be a result of a paint layer applied to housing  102 , but rather, may be a result of the formation and/or manufacturing of housing  102 . In non-limiting examples, the first color of housing  102  and/or outer surface  108  may be or otherwise include black or white. As one example, the first color of housing  102  may be the dominant or majority color for electronic device  100 . 
     As shown in  FIG. 2  and discussed briefly above, marking  110  may be laser-etched on outer surface  108 . In a non-limiting example, marking  110  may be formed on, in and/or substantially through outer surface  108 , and may be positioned substantially in a portion of housing  102  of electronic device  100 . As a result, and as discussed herein, marking  110  may be formed by removing a portion of the material forming housing  102  and/or marking  110  may include a recess  112  formed in housing  102 . 
     Marking  110  may be formed on outer surface  108  of housing  102  using a laser etching process. In a non-limiting example, an ultraviolet laser etching process or an infrared laser etching processing may be performed on housing  102  to form marking  110  on outer surface  108 . As discussed herein the laser etching process utilized to form marking  110  may substantially ablate and/or melt a portion of the ceramic-based material forming housing  102  and/or outer surface  108 . 
     The laser etching process used to form marking  110  may also result in marking  110  formed on outer surface  108  to include a second color distinct from the first color of outer surface  108  and/or housing  102 . That is, and as discussed in herein, the laser etching process may substantially change the physical and/or chemical properties of housing  102  in marking  110  such that marking  110  may include a second color that is distinct from the first color of housing  102  including outer surface  108 . In a non-limiting example where housing  102  and/or outer surface  108  are substantially white in color, marking  110  formed on outer surface  108  using the laser etching process may be substantially black in color. In a further, non-limiting example, housing  102  and/or outer surface  108  may be black, marking  110  formed on outer surface  108  may be white. As a result of the color contrast between outer surface  108  and marking  110 , marking  110  may form a variety of glyphs (e.g., logo, graphic, text, and so on) on outer surface  108  that may be visible to a user of electronic device  100 , similar to that of marking  110  shown in  FIG. 1B . 
     The operational perimeters and/or process of laser etching of marking  110  may be distinct and/or unique from other laser etching processes as a result of marking  110  being formed on a ceramic-based material. In a non-limiting example, because housing  102  is formed from a ceramic-based material (e.g., zirconia alumina), marking  110  may be formed on outer surface  108  with a ultraviolet or infrared laser having specific operational perimeters and/or specific procedures or steps. In addition, the operational perimeters and/or processes of laser etching marking  110  may also be dependent, at least in part, on the color of housing  102  and/or outer surface  108 . These operational perimeters and/or processes performed during the laser etching of marking  110  on outer surface  108  may ensure marking  110  includes a color distinct from the color of outer surface  108  and/or housing  102 , and/or marking  110  is visible to a user of electronic device  100  without the need of paint, as discussed herein. 
     In an non-limiting example where housing  102  is formed from a substantially white ceramic-based material, a diode-pumped, solid-state laser using Neodymium-doped Yttrium Orthovanadate (Nd:YVO 4 ) as a gain element may be utilized the form markings  110  on outer surface  108 . In the non-limiting example, the laser may include the following operational perimeters: 355 nanometer (nm) laser wavelength, 20 nanosecond (ns) pulse width, 100 kilohertz (kHz) laser line width, 600 millimeter per second (mm/sec.) laser cutting speed, and 0.006 millimeter (mm) hatch distance. Additionally in the non-limiting example where housing  102  is formed from a white ceramic-based material, the laser may perform three (3) passes over outer surface  108  with the operational perimeters discussed above to form marking  110  including a substantially black color, which contrasts with the white ceramic-based material forming housing  102 . 
     In another non-limiting example where housing  102  is formed from a substantially black ceramic-based material, a diode-pumped, solid-state laser using Neodymium-doped Yttrium Orthovanadate (Nd:YVO 4 ) as a gain element may include the following operational perimeters: 355 nm laser wavelength, 20 ns pulse width, 100 kHz laser line width, 550 mm/sec. laser cutting speed, and 0.002 mm hatch distance. Additionally in the non-limiting example where housing  102  is formed from a black ceramic-based material, the laser may perform between two (2) and ten (10) passes over outer surface  108  with the operational perimeters discussed above to form marking  110  including a substantially white color, which contrasts with the black ceramic-based material forming housing  102 . 
     It is understood that the type of laser and operational perimeters of the laser used to form marking  110  may be merely exemplary. That is, the specific laser-type and operational perimeters discussed herein may be just some of the many lasers and/or operational perimeters that may be used to form marking  110  on outer surface  108  of housing  102 , such that marking  110  and outer surface  108  include contrasting colors. Additionally, the number of passes the laser may make over outer surface  108  may also be merely exemplary. The number of passes may be any suitable number that may ensure marking  110  includes a color that substantially contrasts the color of the ceramic-based material forming housing  102 , such that marking  110  is visible to a user of electronic device  100 . 
     As shown in  FIG. 2 , marking  110  may form a recess  112  in outer surface  108 . Laser-etched marking  110  may form recess  112  through outer surface  108  and into a portion of housing  102  of electronic device  100  (see,  FIGS. 1A and 1B ). Recess  112  of marking  110  may be formed in outer surface  108  of housing  102  using the laser etching process, as discussed herein. In a non-limiting example, a laser may ablate and/or melt a portion of the ceramic-based material forming housing  102  at outer surface  108 , and may form recess  112  extending into a portion of housing  102 . 
     Recess  112  of marking  110 , as shown in  FIG. 2 , may include a substantially uneven surface  118  formed during the laser etching process. As a result of forming substantially uneven surface  118 , recess  112  of marking  110  may include substantially varied etch depths (ED) within housing  102 . The etch depth (ED) may be the distance recess  112  is formed below outer surface  108 . In non-limiting examples, recess  112  formed in outer surface  108  may include an etch depth (ED) between approximately 2 micrometers (μm) and approximately 8 μm. The etch depth (ED) of recess  112 , as shown in  FIG. 2 , may be dependent, at least in part, on the color of the ceramic-based material forming housing  102 , and the operational perimeters of the laser used to form recess  112 . 
     Marking  110  may also form a raised portion  120  that may substantially surround recess  112  formed in housing  102 . In a non-limiting example shown in  FIG. 2 , marking  110  may include raised portion  120  formed on either side of recess  112 , where raised portion  120  of marking  110  may be positioned above outer surface  108  of housing  102 . Raised portion  120  may be formed during the laser etching process used to form marking  110  on outer surface  108 , as discussed herein. In the non-limiting example, the ablation and/or melting of the ceramic-based material forming housing  102  to form marking  110  may result in a collection of ceramic-based material (e.g., raised portion  120 ) that may not be completely removed from housing  102 . This collection of ceramic-based material may be melted during the laser etching process, but may not be ablated and/or removed. As a result, the previously melted collection of ceramic-based material may harden on and/or above outer surface  108  and may form raised portion  120  of marking  110 . The formation of raised portion  120  of marking  110  above outer surface  108  may be dependent upon the amount of ceramic-based material that is ablated and/or melted from housing  102  when forming marking  110 . As such, the dimensions and/or the etch height (EH) of raised portion  120  positioned above outer surface  108  may vary. In non-limiting examples, raised portion  120  of marking  110  may be positioned above outer surface  108 , and include an etch height (EH) between approximately 1.4 μm and approximately 2.5 μm. 
     Housing  102  may include a heat affected region (HAR)  122 , shown in phantom. In a non-limiting example shown in  FIG. 2 , housing  102  may include HAR  122  positioned adjacent to and/or substantially surrounding marking  110  formed in housing  102 . Additionally, HAR  122  may be positioned substantially below outer surface  108  of housing  102 . HAR  122  may be positioned below outer surface  108  by a distance (D) dependent, at least in part, on: the material composition of the ceramic-based material forming housing  102 , the color of the ceramic-based material forming housing  102 , the operational perimeters of the laser used in the laser etching process for forming marking  110 , and the etch depth (ED) of recess  112  in housing  102 . In non-limiting examples, HAR  122  may be positioned below outer surface  108  of housing  102  a distance (D) of approximately, 5 μm and approximately 14 μm. 
     HAR  122  may be formed during the laser etching processes performed on housing  102  to form marking  110 . That is, HAR  122  may include a portion or region of the ceramic-based material forming housing  102  that may be affected by the laser and the laser etching process performed on housing  102  and/or outer surface  108  to form marking  110 . HAR  122  may include a region or portion of the ceramic-based material forming housing  102  that may be heated by the laser used in the laser etching process forming marking  110 , but the ceramic-based material in HAR  122  may not be ablated and/or melted. As discussed herein, the laser etching process may affect HAR  122  by changing and/or altering the chemical composition of the ceramic-based material included in HAR  122  when compared to the remainder of the material in housing  102  and/or outer surface  108 . 
     Although shown to include a substantially uniform, geometric shape (e.g., semi-circular), it is understood that HAR  122  may include a substantially non-uniform region or portion of the ceramic-based material forming housing  102  that may be affected by the laser etching process. HAR  122  shown in  FIG. 2  as being semi-circular is merely exemplary, and may only be depicted as being semi-circular to show how HAR  122  is generally formed within housing  102  as a result of the laser etching process. In another non-limiting example, HAR  122  may take a similar shape corresponding to the shape of recess  112  formed in housing  102 . 
     As briefly mentioned above, the laser etching process performed on housing  102  and/or outer surface  108  to form marking  110  may alter the chemical composition of marking  110  and HAR  122 . In a non-limiting example, the ablation and/or melting of a portion of the ceramic-based material of housing  102  to form marking  110  and HAR  122  may also change the chemical composition of the material formed within marking  110  and HAR  122 . In the non-limiting example where housing  102  of electronic device  100  is formed from white (e.g., color) zirconia alumina (ZrO 2 Al 2 O 3 ), the ablating and/or melting of the material to form marking  110  may change the chemical composition of marking  110  and HAR  122  from zirconia alumina. In the non-limiting example, marking  110  may be formed from a resolidified portion of the material forming housing  102  that has been melted, but not ablated from recess  112 . The resolidified portion of material forming marking  110  may primarily include zirconia (ZrO 2 ), with a small percentage-by-weight of aluminum (Al) and carbon (C). The material forming marking  110  may include a loss of oxygen (O) during the laser etching process, and specifically, when melting the zirconia alumina to forming marking  110 . 
     Additionally in the non-limiting example, portions of the material included in the HAR  122  may also include chemical composition changes or alterations. In a non-limiting example, some portions of the material affected by the laser etching process, and specifically the heat of the laser used to ablate and/or melt the material, may primarily include zirconia (ZrO 2 ) as well. However, these portions of material included in the HAR  122 , when compared to the material of marking  110 , include more oxygen (O) and aluminum (Al), and approximately the same amount of carbon (C). Distinct portions of material in HAR  122  may primarily include Alumina (Al 2 O 3 ), with a small percentage-by-weight of carbon (C). These chemical composition changes or alterations, in conjunction with the change in the optically reflective properties of marking  110  as discussed herein, may form the contrast in colors between outer surface  108  of housing  102  and marking  110  formed therein. 
       FIG. 3  shows an enlarged cross-section view of housing  102  of electronic device  100  including a portion of marking  110  formed in outer surface  108 , as similarly discussed herein with respect to  FIGS. 1 and 2 . More specifically,  FIG. 3  shows how light-rays interact and/or reflect off of outer surface  108  of housing  102  and marking  110  formed on outer surface  108  during use of electronic device  100 . It is understood that similarly numbered components may function in a substantially similar fashion. Redundant explanation of these components has been omitted for clarity. 
     As shown in  FIG. 3 , incident rays (IR) of light may be directed toward housing  102  of electronic device  100 . The provided incident rays (IR) may contact a surface (e.g., outer surface  108 , uneven surface  118 ) and may subsequently be reflected, producing reflected rays (RR)(shown in phantom). The path of reflected rays (RR) reflecting off of housing  102 , in conjunction with the material composition of housing  102 , may directly affected the perceived color of housing  102  by a user of electronic device  100 . In the non-limiting example discussed above where housing  102  is formed from white zirconia alumina (ZrO 2 Al 2 O 3 ), outer surface  108  of housing  102  may appear to be white, as a result of the path of reflected rays (RR). As shown in  FIG. 3 , the angle at which the incident rays (IR) are directed toward outer surface  108  is substantially equal to the angle at which the reflected rays (RR) are directed away from outer surface  108 . As such, outer surface  108  may substantially reflect and/or not affect the color (e.g., white) of housing  102 . 
     As shown in  FIG. 3 , the incident rays (IR) that are directed toward uneven surface  118  of marking  110  may include the same angle as the incident rays (IR) directed toward outer surface  108 . However, as shown in  FIG. 3 , reflected rays (RR) reflected from uneven surface  118  of marking  110  may not include a similar angle as the incident rays (IR) provided to uneven surface  118 . In the non-limiting example, the angle and/or path in which the reflected rays (RR) may be reflected is distinct, based on the angle and/or position of uneven surface  118  of marking  110 . The reflected rays (RR) reflecting from uneven surface  118  of marking  110  may be reflected in non-uniform or scattered angles or paths, as a result of marking  110  including non-planar, uneven surface  118 . The non-uniform and/or scattered reflected rays (RR) reflecting from uneven surface  118  of marking  110  may affect the color of marking  110  viewed by a user of electronic device  100 . More specifically, because reflected rays (RR) are reflected in a scattered pattern as a result of uneven surface  118 , marking  110  may appear to have a contrasting dark, or black color when viewed by a user of electronic device. 
     As a result of the foregoing and/or as a result of contrasting colors due to the reflective properties of outer surface  108  and/or uneven surface  118 , marking  110  may be formed on housing  102  of electronic device  100  to provide a visible glyph or design, without the need of paint, or the process of painting housing  102 . 
       FIG. 4  shows an enlarged cross-section view of housing  102  of electronic device  100  including a portion of marking  110  formed in outer surface  108 , as similarly discussed herein with respect to  FIG. 2 . As shown in  FIG. 4 , outer surface  108  of housing  102  may be substantially annealed. In a non-limiting example, outer surface  108  of housing  102  may undergo an annealing process to form a substantially annealed portion  124  of the ceramic-based material forming housing  102  on outer surface  108 . By annealing outer surface  108  and/or housing  102 , annealed portion  124  may be reflowed, and/or may include a portion of ceramic-based material forming housing  102  that may be partially melted and then subsequently resolidified to form a polished and/or substantially planar outer surface. As discussed herein, the polished and/or planar outer surface of housing  102  may ensure housing  102  will include a desired color visible by the user of electronic device  100 . 
       FIG. 5  may also show an enlarged cross-section view of housing  102  of electronic device  100  including a portion of marking  110  formed in outer surface  108 , as similarly discussed herein with respect to  FIG. 2 . As shown in  FIG. 5 , both outer surface  108  and uneven surface  118  may include a reflective layer  126 . In a non-limiting example, reflective layer  126  may cover and/or may be formed over both outer surface  108  of housing  102  and uneven surface  118  of marking  110 . Reflective layer  126  may be formed over the respective surfaces of housing  102  to increase the reflective properties of the surfaces, as discussed herein with respect to  FIG. 3 , to ensure a user views outer surface  108  as a desired color (e.g., white). Additionally, reflective layer  126  may be formed over uneven surface  118  of marking  110  to increase the reflective properties to ensure a user views marking  110  as a desired color (e.g., black) that is distinct from the color of outer surface  108  of housing  102 . Reflective layer  126  may include any suitable material that may increase the reflective properties of the surfaces of housing  102 . In a non-limiting example, reflective layer  126  may be formed from a paint including substantially reflective properties. 
       FIG. 6  depicts an example process for forming a ceramic-based component for an electronic device. Specifically,  FIG. 6  is a flowchart depicting one example process  600  for forming a ceramic-based housing for an electronic device, as discussed above with respect to  FIGS. 1A-5 . 
     In operation  602 , an outer surface of ceramic-based component may be laser-etched. More specifically, a laser etching process may be performed on the outer surface of the ceramic-based component to substantially ablate a portion of the ceramic-based component and/or melt a portion of the ceramic-based component. The laser etching process performed on the outer surface of the ceramic-based component may include performing an ultraviolet laser etching process or performing an infrared laser etching process. The laser etching process performed in operation  602  may also include performing a plurality of passes over the outer surface of the ceramic-based component with the laser. That is, the laser performing the laser etching process may pass over substantially the same portion of the ceramic-based component multiple times when performing the laser etch. 
     In operation  604 , a laser-etched marking may be formed on the outer surface of the ceramic-based component. In response to performing the laser etching process, a marking may be formed on the outer surface of the ceramic-based component. The formation of the laser-etched marking may also include forming a recess in the outer surface of the ceramic-based component. The recess may include a substantially non-planar, uneven surface. When performing the laser etching process and/or forming the laser-etched marking and/or recess on the outer surface of the ceramic-based component, the chemical composition of the component may be altered. That is, the formation of the marking and/or the recess may result in an alteration of the chemical composition of a portion of the ceramic-based component included within the recess. The chemical composition of the material included within the recess may be distinct from the chemical composition of the material forming the remainder of the ceramic-based component. 
     In operation  606 , the optically reflective properties of the material included in the marking may be altered. That is, in response to performing the laser etching process to form the marking, the optical reflective properties of the material included in the marking may be altered, affected and/or changed. As a result, the marking may appear to be a distinct color than the rest of the ceramic-based component. 
     In optional operation  608 , shown in phantom, the ceramic-based component including the laser-etched marking may be annealed. More specifically, the ceramic-based component including the recess of the marking formed on the outer surface of the component may be annealed to at least alter the state of a portion of the material forming the component. As a result of the chemical composition change within the material included in the recess of the laser-etched marking in operation  604 , the material forming the marking may not be affected during the annealing process. 
     In optional operation  610 , shown in phantom, a portion of the material included in the outer surface of the ceramic-based component may be reflowed. More specifically, a portion of the material of the annealed ceramic-based component may be reflowed to form a substantially planar, polished outer surface of the component. The ceramic-based component may be annealed in operation  608 , to reflow a portion of the material on the outer surface to substantially enhance the color contrast between the outer surface and the laser-etched marking. When the outer surface includes a reflowed portion of material that may form a substantially planar, polished outer surface, the ceramic-based component, excluding the marking, may include a single color visible by the user. The reflowing may ensure the outer surface includes the single color of the ceramic-based component that is distinct from the color of the marking formed using the laser etching process in operation  602 . 
     Although not shown, an additional operation may include applying a reflective layer to ceramic-based component. The reflective layer may be applied to the outer surface of the ceramic-based component, and the substantially non-planar, uneven surface of the recess of the laser-etched marking. The reflective layer may be applied to the surfaces of the ceramic-based component to substantially enhance the optically reflective properties of different surfaces of the component. By enhancing the reflective properties of the layers of the ceramic-based component, the reflective layer may ensure that the outer surface of the component includes or provides a first visible color to a user, while the laser-etched marking provides a second visible color to the user distinct form the first color. 
     Although a ceramic-based component is discussed herein to include a marking having a contrasting color with the color of the component, it is understood that other effects and/or visual characteristics may be created on the ceramic-based component using the laser etching process. That is, the laser etching process discussed herein may be used to lighten, darken and/or polish at least a portion of an outer surface of a ceramic-based component to produce a desired cosmetic effect on the outer surface of the component. In a non-limiting example, the recess formed in ceramic-based component as discussed above, may be substantially shallow, and may be darkened (e.g., color change). In this example, the recess may not be deep enough to form a marking on the ceramic-based component as discussed above, but rather, may provide a shadow effect on the outer surface of the component. This shadow effect may be used in conjunction with markings formed on the component or other features of the component to provide a desired cosmetic effect. 
     In addition, the lightening, darkening and/or polishing, as discussed herein, may be used on a plurality of surface and/or components to produce a desired cosmetic effect. In addition to performing the processes as discussed herein on a substantially planar outer surface of a ceramic-based component, the processes may be performed on protrusions, seams, chamfers and/or any other suitable shape, component or configuration of an electronic device to provide desired cosmetic effects. 
     As discussed herein the laser etching process may include ablating and/or melting a portion of the material included in the ceramic-based component. In addition, the laser etching process and/or the process of forming the recess within the component may include knurling, forming, machining, drilling and/or any other suitable material removal process. Furthermore, the marking may be formed without the need of masking, or may be formed on a part that has been anodized or includes an oxide layer. When forming the marking on the anodized component, the marking may be formed through the oxide layer as well. 
     The process of laser etching the marking on the outer surface of the ceramic-based component may result in the formation of a recess in the ceramic-based component and, a contrast in colors between the outer surface and the laser-etched marking or recess. More specifically, the process of ablating and melting a portion of the ceramic-based component during a laser etching process may result in a color/optical contrast between the laser-etched portion (e.g., marking or recess) and the unaffected, outer surface of the ceramic-based component. The color/optical contrast may be formed as a result of the way light interacts with and/or reflects from the outer surface of the ceramic-based component, in contrast to the uneven, laser-etched marking or recess formed in the ceramic-based component. By forming a color contrast between the outer surface of the ceramic-based component and the marking or recess formed on the surface of the ceramic-based component, the need for painting a design, text or logo on the component may be unnecessary. As such, the manufacturing time and/or cost of forming a ceramic-based component for an electronic device may be reduced. Furthermore, the marking formed on the surface of the ceramic-based component may be substantially permanent, and may not wear off, distort and/or fade over the life of the electronic device. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20150224
Publication Date: 20200505
Grant Date: 20200505
Priority Date: 20140620
Inventors: NASHNER, MICHAEL S.
RUSSELL-CLARKE, Peter N.
Assignee: APPLE INC
CPC Classifications: [{"code": "B23K26/354", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0252", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0252", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K26/354", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K26/408", "inventive": true, "first": true, "tree": "[]"}, {"code": "B23K26/365", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K26/40", "inventive": true, "first": true, "tree": "[]"}, {"code": "B23K26/362", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K2103/52", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23K26/364", "inventive": true, "first": true, "tree": "[]"}, {"code": "B23K26/354", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 70461453