The LLO process has been adopted for:
・ Separation of sapphire substrate in production of high brightness vertical structure LEDs ・ Detachment of blue/green micro LEDs (μ-LED) formed on sapphire substrate ・ Separation of bonded glass substrate used for warpage correction
Laser lift-off is a processing technology which irradiates a high power laser on the interface of the workpiece material in order to separate it from the substrate by dissolving the interface. DISCO’s LLO process employs a diode pumped solid-state laser (DPSS). The processing laser power has a homogeneous energy within the laser-spot diameter so that it can achieve stable processing quality without variation. Furthermore, it employs a “spiral process” using a unique optics system to achieve high productivity.
In order to improve the brightness and heat resistance, the light emitting layer is attached to a conductive substrate which has a higher thermal dissipation. DISCO’s LLO is used for the sapphire separation process, suppressing damage on the light emitting layer, minimizing separation failure, and improving the surface roughness of the detached surface, resulting in higher brightness compared to the existing process.