LED substrate market analysis

LED epitaxial silicon substrate technology can replace the mainstream status of sapphire substrate, has been the focus of debate in the LED industry in the past few years, sapphire substrate high chemical stability, does not absorb visible light, coupled with mature manufacturing technology, has been the mainstream of LED epitaxial substrate Materials, and the ruthenium substrate that is picked up when the price of sapphire substrate is high, have the characteristics of large size, low cost, easy processing, and easy conduction. They were once placed high on replacing sapphire. However, as the price of sapphire comes back to a reasonable range, The price and cost advantages of the substrate are weakened. In addition, the defects in the visible light absorption of the silicon substrate have caused the yield problem to remain unresolved. This has weakened the original cost advantage, and the silicon substrate may gradually fade out of the LED market.

The sapphire substrate VS germanium substrate sapphire substrate is the mainstream substrate material for LED epitaxy. The sapphire substrate has high hardness, high temperature resistance, high chemical stability, mature manufacturing technology, and does not absorb visible light. The sapphire substrate was once at the price in 2010. As a result, the proportion of the cost of epitaxial wafers was once increased to 30%, and the larger size and lower material cost of the silicon substrate were achieved at the same time. However, as the supply of sapphire substrates was sufficient, the price returned to a reasonable range. Sapphire The substrate is still the best choice for the epitaxy industry.

Compared to the sapphire substrate, the size of the silicon substrate has already reached more than 8 inches, while the current mainstream of the sapphire substrate is still at 2 and 4 turns. The silicon substrate has the advantage of low material cost, plus it has easy processing and good conductivity. Thermal conductivity and thermal stability. On the other hand, the semiconductor process was transferred to a 12-inch epitaxial wafer. The cost of the 8-inch substrate machine was reduced. However, the germanium substrate absorbs visible light, and the germanium substrate is the epitaxial thin film due to the absorption of visible light. The difference in the thermal expansion coefficient between the silicon substrate and the substrate is likely to cause stress relief, resulting in cracking of the epitaxial layer, and the yield problem becomes the greatest resistance to the silicon substrate development.

Bridgelux and Toshiba Alliance stagnation The biggest proponent of the use of germanium substrates for LED epitaxy is Bridgelux and the Toshiba Alliance. The Bridgelux GaN-on-Silicon technology was transferred to Toshiba for use. In 2013, a new round was included. The cooperation between technology licensing and production supply has been expanded. However, whether Toshiba has successfully mass-produced silicon-on-board LEDs and the outside world is still watching the market. The market is also waiting for the technical progress of Bridgelux and Toshiba.

TSMC solid-state lighting trend TSMC solid-state lighting, taking advantage of TSMC's leading technology and position in wafer epitaxial wafers, initially chose to cut into the LED market with a helium substrate approach. The yield of Titanium-substrate LED of TSMC solid-state lighting has improved, but due to sapphire Excess substrate supply, sapphire substrate prices fell, the overall cost-effective sapphire substrate is still relatively high, the industry's willingness to use silicon substrates decline, while the development trend of the Taiwan Semiconductor Solid-State Lighting substrate has also continued to receive the industry's attention.