Apple has been granted a Patent relating to the Electrochemical Etching Process of Titanium Alloys for use with MacBooks, iPhones & more
Patently Apple posted an IP report on Apple exploring the use of titanium in future Apple devices way back in April 2017, years before any rumor. Thereafter we posted six additional reports (01, 02, 03, 04, 05 and 06) regarding the possibility of using titanium prior to Apple introducing the Apple Watch Ultra that was the first Apple device to use titanium. Apple's marketing states: "To build the ultimate sports watch, we crafted every element with painstaking attention to detail for unparalleled performance. Titanium strikes the perfect balance between weight, ruggedness, and corrosion resistance."
Today the U.S. Patent and Trademark Office officially granted Apple a patent titled "Titanium Part Having an Etched Surface."
In Apple's background they note that enclosures for portable electronic devices may be formed from a combination of metal and non-metal materials. However, metal lacks a natural ability to attach to these non-metal materials. Moreover, conventional techniques for modifying metal parts, in an attempt to provide a strong attachment between these metal parts and non-metal parts, have proved unsuccessful. In one example, surfaces of these metal parts may be superficially roughened. However, this superficial roughness is hardly sufficient to provide the ideal structure for bonding metal parts to non-metal parts.
Apple's granted patent generally relates to etching a surface of a titanium part. More particularly, the described embodiments relate to techniques for forming an interconnected network of channels throughout the titanium part by using an electrochemical etching process.
According to some embodiments, a titanium alloy substrate for a portable electronic device is described. The titanium alloy substrate includes an exterior surface and a branching channel structure that includes a first channel and a second channel, where the first channel is defined by a first channel wall that extends away from a first opening in the exterior surface, and the second channel is defined by a second channel wall that extends away from a second opening in the first channel wall.
According to other embodiments, an enclosure for a portable electronic device is described. The enclosure includes a first portion including a metal substrate, the metal substrate including an interconnected network of channels. According to some embodiments, the channels include a first channel defined by a first channel wall, where the first channel wall extends from a first opening in an external surface of the metal substrate and terminates at a first terminus surface within the metal substrate, and a second channel defined by a second channel wall, where the second channel wall extends between a second opening in the external surface of the metal substrate and a third opening in the first channel wall. According to some embodiments, the enclosure further includes a second portion including protruding features that extend through the first and second openings and into the first and second channels.
Yet in other embodiments, a method for forming a part for a portable electronic device, the part including a titanium alloy substrate, is described. The method includes exposing an exterior surface of the titanium alloy substrate to an electrochemical etching process, where the electrochemical etching process forms (i) an opening in the exterior surface and a first channel defined by a first channel wall that extends from the opening, and (ii) an opening in the first channel wall and a second channel defined by a second channel wall that extends from the opening in the first channel wall.
Apple's patent FIG. 1 below illustrates that Apple is considering the use of Titanium beyond Apple Watch Ultra to possibly include a MacBook Pro, iPad Pro and iPhone; FIG. 5 illustrates a method for forming an etched part; and FIG. 6 illustrates an exemplary top-down image of an etched metal part.
Apple's patent FIG. 4B illustrates a magnified cross-sectional view of the multi-layer part #250. As illustrated in FIG. 4B, the polymer material of the protruding features—F.sub.1, F.sub.2, F.sub.3, F.sub.4—fills in grooves of the walls 234, such as during an injection molding process. As illustrated in FIG. 4B, the non-metal layer 252 is disposed over the metal substrate 204.
For more details, review Apple's granted patent US 11511519 B2.
James Curran: Anodizing research and development / Materials Engineer (Alloy Engineering)
Todd Mintz: Materials Engineer
Isabel Yang: Materials Product Design Engineer