Sapphire substrate applications have shifted from LED to smartphones, according to a report by Taiwanese media UDN. Apple was the first to apply the material in its iPhone home button, and has recently expanded sapphire substrate applications to fingerprint recognition sensors, camera outer case, and even the entire smartphone monitor. As a result, Taiwanese manufacturers are close to full production capacity. ACME Electronics Corp. subsidiaries including USI Optronics Corp., Crystal Applied Technology Inc., ProCrystal Technology Co., and Crystalwise Technology Inc. have launched a new wave of expansion.

Apple has filed a patent titled “Sapphire Laminate” that describes sapphire substrate applications in consumer electronic devices and mass production, according to an United States Patent and Trademark Office announcement last week. Related documents were first published in March, and the goal of the patent is to lower sapphire substrate processing costs, so it can become an extremely scratch resistant protective layer on tablets and might become a monitor component in devices.

In the past a 2-inch sapphire substrate could be cut into 55 iPhone cameras, but only 16 sapphire substrate home buttons can be made from the same sized substrate, due to its larger size. The home button’s bigger size adds difficulty in the manufacturing process, and can effectively rid sapphire substrate production capacity. Originally, the main application for sapphire substrates was the LED market that had an annual demand of about 4.5 million pcs for 2-inch sapphire substrates. However, a whole new market has opened up with the addition of smartphone applications, according to a manufacturer’s analysis. iPhone’s rear camera lens cap alone uses 1.5 million sapphire substrate pcs, equivalent to a third of sapphire substrate supplies. If the Apple iPhone home button enters the market, the sapphire substrate volume usage will be triple of that for camera lens cap, and result in supply shortages.