Sapphire substrate application has come a long way from the original usage in military applications in the 1960’s. This year alone has seen some major shifts in application with Apple’s new integration of sapphire substrate into smartphone design. While LEDs and general lighting continue to make up a major chunk of sapphire substrate market share, non-LED application usage has had a dramatic increase this year. Increasing penetration rates for LEDs and rise in non-LED applications, the next few years look bright for sapphire substrate market growth. 

Sapphire substrates are ideal for use in LED and non-LED applications due to high temperature resistance, high strength, good electrical insulation, and low dielectric loss. Sapphire substrate in LED lighting helps prevent stray currents caused by radiation from spreading to nearby circuit elements. Its crystal structure also allows LED lights to have a wider beam angle. The high strength of sapphire substrate make it more scratch-resistant and therefore suitable for covering lenses, buttons and deplays for non-LED applications such as smartphones.

There has recently been a rise in silicon substrate and GaN substrate usage due to their ability to combine electrical parts and LED optical parts, increasing LED product efficiency. Japanese manufacturer Toshiba and American based company Bridgelux are both actively pursuing this market. However, with the LED market price war intensifying and manufacturers focused on cutting costs, it is unlikely that manufacturers will be willing to make the switch due to high cost and technology still in the developmental stage. LEDinside believes that sapphire substrate in LED applications will still be hard to replace for the time being. Silicon substrate and GaN substrate can only be used in more specialized applications and do not pose much of a threat to sapphire substrate.

Sapphire substrate wafer size has also gone through changes this year. Use of larger sized wafers for LED lighting cuts down on costs. In the past, 2 to 4-inch sized wafers were the commonplace, but there has been a recent transition towards 6 to 8 inch wafers. Larger sized wafer allow manufactures to incorporate more LED chips along the outside edge, increasing brightness of the LEDs. The use of patterned sapphire substrate (PSS) can further increase brightness due to reduction in density of GaN layer and enhancement of light extraction efficiency. With penetration rate for LED-based general lighting continuing to rise, large-sized PSS will become necessary to meet demands of the rapidly growing lighting market, according to Rubicon Technology.

There has been recent discussion in the industry of the possibility in 2014 for sapphire substrate to replace glass in smartphone display screens. Market insiders believe that with the current price of sapphire substrate used in smartphone screens being 3-4 times lower than that of glass substrate, OEM and ODM companies will be more willing to use sapphire substrate. It is estimated that by the second half of 2014, sapphire substrate might be used in smartphone screens, which is hoped to drive the next wave of sapphire substrate growth. However, at the same time some in the industry see this to be less likely. Although stronger than glass substrate, transparency for sapphire substrate is lower and can lead to optical distortion. Also, a single sapphire substrate unit is 67 percent heavier than a same sized glass substrate, which is not beneficial to lowering costs. When considering the characteristics and economic scale of sapphire substrate, phones with sapphire substrate screens are more likely to be seen in niche markets.

The sapphire substrate industry is anticipated to grow due to the influx of new non-LED applications. Increased demand in applications such as smartphones, camera lens covers, and watches are hoped to reverse the market’s over-capacity problem in 2014. Manufacturing therefore might experience price fluctuation next year. As sapphire substrate is still a key building block for LEDS, general lighting is expected to continue providing solid demand for substrate material from the LED industry in the following years.