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Laser cutting sapphire LED chip
May 21 , 2021Laser cutting sapphire LED chip
The development of LED chips continues to develop in the direction of high efficiency and high brightness. Traditional chip cutting methods such as diamond scribing and grinding wheel sawing are gradually outdated due to their low efficiency and low yield, and cannot meet the needs of modern production. At present, laser cutting methods are gradually replacing traditional cutting and become the current mainstream cutting method.
Laser cutting is divided into surface cutting and internal cutting, namely invisible cutting. It uses a certain wavelength of laser to focus on the surface or inside of the wafer, release a large amount of heat in a very short time, melt or even vaporize the material, and cooperate with the movement of the laser head or the movement of the object to form cutting marks to achieve the purpose of cutting. After the surface layer is cut, the high energy generated by the laser instantly destroys the lattice structure of the sapphire, and the side laser burn marks block the light from the LED chip, which has a greater impact on the off-chip quantum efficiency.
The laser cutting of the sapphire substrate LED chip applies an external force to the LED chip wafer along the crack direction to separate the chip into independent light-emitting units. For the cutting of thicker wafers with sapphire substrates, the invention can effectively improve the cutting yield and reduce the phenomenon of sapphire oblique cracking.