LEDs are widely-used for the purpose of energy conservation and longer life use. Key features of LED are good visibility and smaller size.
Current situation in LED manufacturing process
The ongoing trend is miniaturization of LED chips, bringing the size - down to 150nm and 100nm thickness, fitting for mass production. Complete micro devices are very small. Recent increase in LED applications on global basis generates more productive manufacturing process for LED wafers and better yield management in essence more demanding in LED wafers process - It is imperative that unity of brightness and　emission color are critical for beefing up of quality.
Fujikom's proposal for LED manufacturing process
At present, inspection of LED wafers is mostly done visual inspection by operators. However, Fujikom designed and developed a new inspection machine called "POLESTAR", which is capable of advancing the process speed and automation for obtaining quantitative inspection results.
Features of POLESTAR
It can detect yield loss and automatically identify defective chips. Visual inspection can not handle wafer warping, variable film thickness and correction of brightness. If these factors are known, then can be actually feedback to the manufacturing process.
Applications of POLESTA
PSS process, Lithography process, EPI process, ITO process, Electrode formation process, and dicing process
Process Management of POLESTAR
PSS abnormal pattern, Exposure trend, Growth of epitaxial layers, Electrode breaks, Crack by dicing
PORELSTAR Line-up
- POLESTAR FE
- It is designed for pre-dicing stage. and functions for wafer manufacturing process that is the most important in manufacturing. Its applications range from wafer acceptance. Epi growth, Chip pattern formation to all proceeses. It also identifies a place on each wafers where yield loss is likely to occur.
- POLESTAR BE
- It is designed for post-dicing for LED chips. It can be achieved with dicing frames with LED chips. By sharing data networking with POLESTAR FE. It can not only detect cracks inside and outside of LED chips, but also classify grade by selecting the same brightness of each chip
- POLESTAR ML
- It is designed for photo mask inspection. By networking with POLESTAR FE , cleaning and replacing timing for masks are controlled based on real-time check-ups, which results in the reduction of overall manufacturing costs
POLESTAR supports from 2 inch to 8 inch LED wafers, and LED chips after dicing and photo mask. Method of wafer handling is variously available.
