Katsumi Araki

Account Manager | Toray Engineering
Katsumi Araki

Toray Engineering has developed series of technologies to manufacture micro-LED displays based on technologies cultivated through its manufacturing equipment of LCD displays and semiconductors. By combining these technologies, Toray Engineering offers proposal for total solution, and so far, has large delivery records of micro-LED-related manufacturing equipment worldwide. In this presentation, Toray Engineering’s approach to the manufacturing process that utilizes its visual inspection system that uses photoluminescence technology, laser repair equipment, mass transfer equipment, and laser mass transfer equipment shall be introduced. Toray Engineering’s approach focuses measures against these main challenges ahead for the Micro-LED Display Manufacturing:

  • Smaller micro-LED chips & Stable process
  • It is important which method we use to achieve stable process in Micro LED.
  • Efficient repair process

In case of watch production, 500k chips are used in per product. So if the defect rate is 1%, 5 thousand chips need repairs.In case of a TV, 25 million chips are used. So 250k (two fifty thousand) chips need repairs.

  • Minimizing of image discoloration
  • Micro-LED chips have variation in luminance and wavelength caused in their manufacturing process. If such variations are transferred to the display pixels, they result in uneven images or mura. There is a need to reduce such image mura.

Toray Engineering is ready to offer total solutions to overcome these challenges to help realize high volume production of micro-LED display in the near future.


Katsumi Araki has joined Toray Engineering Co., Ltd. in 2017. After spending one year as an engineer for the slot-die coater and laser equipment, he has been working in the Sales Department since 2018. He is mainly in charge of sales and marketing for the manufacturing equipment of Micro LED.