This February word leaked that Apple’s plant in Arizona was cooking up something exciting. Behind the buzz was a bunch of speculation about the plant’s recent receipt of a shipment of new Sapphire manufacturing equipment. What was behind the new equipment, insiders wondered. Word on the street was that the materials gave Apple the capacity to manufacture enough synthetic sapphire to double the current global output. As more details have become available, Apple’s CEO hinted at a “secret project” that the materials would be used for, rather than to create new iPhone display covers, as had been suspected.
Sapphire which is stronger than guerilla glass necessitates specific laser cutting tools that can handle its tough surface. Conventional processing of this would be cumbersome and costly. A new patent submitted by Apple is specifically for a special laser cutting technique that they have designed to make their processing of Sapphire more cost-effective.
A Story of Sapphire
Sapphire, also known as aluminum, was the metal chosen for the pyramid of the Washington monument. The rationale behind this choice was that sapphire has the best of many desirable qualities; it’s incredibly light and corrosion resistant, durable, yet pliant enough to be cast in the form of a cone. Corundum, the crystalline form of aluminum oxide, which is popularly known as sapphire (or ruby for red corundum), is considered a precious gem or stone. The strength of this metal is such that it can nick virtually any other mineral. And that strength coupled with its transparency makes it ideal for a multitude of different applications. The challenge, in using corundum, however, is that it can really wear down conventional processing tools.
The Apple Laser Cutting Solution
Apple’s new patent appears to get around this challenge in several ways. Firstly, by providing a method for better cutting of hard, transparent materials with polished surfaces, specifically directing a laser beam onto the rough portion to melt and cut through it. Secondly, by producing a system designed to prepare and cut polished corundum.
In Apple's patent FIG. 3C, an embodiment is illustrated showing a laser being used to roughen the surface of the sapphire. Also, the laser appears able to move relative to the sapphire member, thereby etching a cutting pattern on its surface. Laser cutting, such as this, enables highly precise cutting, controlled by computer. In the patent’s roughening technique the pattern is chemically etched.
Possible applications are hinted at in Apple's patent FIG. 8, which illustrates an iPhone, in which a sapphire member could be implemented. The next figure shows a sapphire wafer that may be the source of multiple sapphire components. Finally, in Fig. 10 an example of a sapphire processing and growth system is illustrated and the system includes slicers and polishers, typically pre-processing equipment. Apple indicates that this system is will create increased efficiencies and save costs by laser cutting of sapphire in the long-term.
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