Ray-Sun LED filament bulb can satisfy both the market demand of environment protection and energy-saving and customers' need of filament bulb's function. The Ray-sun filament of this product is made of sapphire substrate but not ceramics or copper, because sapphire possesses many advantages that ceramics and copper have not.
Sapphire filament has excellent thermal conductivity because it can even resist 2050 degree high temperature. Moreover, no matter how the internal temperature changes, problems such as deformation or fracture won't happen due to thermal expansion and contraction.
Sapphire is the main material of the LED chip. Adopted sapphire substrate filament, the life-span of bulb can be largely extended because the combination of LED chip sapphire substrate filament has good physical properties.