Nowadays, the majority of filaments LEDs are made on sapphire substrates, on which crystals are placed and then they are covered by continuous layer of phosphor. Sapphire production technology is energy-intensive, time-consuming and rather pretty expensive.
RUSALOX has produced the first al oxide filament circuits, which are already being tested by one Chinese filament manufacturing giant. The al oxide filament circuits have aluminum base with the thickness of 0.35 mm, on which surface the oxide layer is grown and the bonding pads are made. In its turn, these give us a possibility to make the al oxide substrates with the properties similar to the artificial sapphire ones, but the production process is less resource-intensive and less time-consuming.
It is necessary to note that there are two main differences between al oxide filament circuits and the existing market offerings (particularly, the sapphire substrates): the lack of transparency and high thermal conductivity. Manufacturers claim that the filaments are to deliver the scattering light angle of 360°. Meanwhile, they are using substrates with a matte surface or altered texture, which leads to losses of luminous flux through the substrate. With the help of the al oxide technology, the problem of light diffusion 360° is not an issue anymore as it can be solved in two ways: either by bilateral enforcement of the al oxide substrate, or by substrate’s location geometry inside the final product.
The existing filament LEDs are limited in their power up to 1 W only due to the problem of heat dissipation. Engineers and designers do know how to solve this issue – either to use high thermal conductivity gases in flasks or to increase the size of these flasks. Due to the technical properties and, especially, to high thermal conductivity, al oxide filament circuits dissipate heat from the crystals much more effectively while allowing to increase the power of filament LEDs.
We do see how the market of LEDs is changing and the modern shift to filament LEDs is to become more demanded in the nearest future. RUSALOX al oxide substrates is the first big step in a qualitative change of the structure of LED retrofit.