The organic EL display (OLED) used in the latest smart phones is distinctive for its vivid image and ultrathin size. Special attention to dimension measurements during the evaporation process of the organic emitting layer production process are crucial to that high picture quality. Shinto S-Precision’s products have put this technology to many uses from its development and trial phase to the mass production phase, and are now releasing new products in keeping with the development of OLED technology.
LTPS panel measurements
The LTPS panel used in a Liquid Crystal Display is also used in the organic EL panel’s backplane (circuit board). During production of the LTPS panel, the total pitch and CD/overlay series are measured by SMIC Series and μ-Master Series. (For more details, please refer to the [Liquid Crystal Display] page.)
Measurement of the metal mask used in evaporation
The three color RGB organic emitting layer panel is evaporated on the LTPS using vacuum evaporation equipment, and the dimensions of the metal mask used for evaporation are measured.
After it has been used a certain number of times, the metal mask must be cleaned before it can be used in the evaporation process again, so measurements must be taken after cleaning as well to check for changes in dimensions. The metal mask manufacturers also measure it before shipping.
The metal mask’s aperture and rib dimensions, overall length and position displacement (distortion) of the evaporation area, and the amount of surface bend, are all measured. In order to accurately measure the heavy metal mask, an extremely rigid measurement table is used to curb deformation of the metal mask during installation.
OLED panel measurement
After the organic emitting layer has been evaporated onto OLED panel, its positions are measured. RGB color emission, color image processing, and high level edge detection are also necessary for this measurement, so it is used not just for measurement but also for surface observation. The measurement result is also used in the adjustment of the evaporation equipment.