Imec pushes OLED pixels to 1250 ppi resolution
- الكاتب:Ella Cai
- الافراج عن:2017-09-26
Imec has developed cost-effective fine-pixel photolithography for manufacturing ultra-high resolution OLEDs.
Imec, and its development partner Chunghwa Picture Tubes (CPT) , aimed to push pixel density beyond 1000 ppi.
Imec and CPT have verified that a novel photolithography process can allow for ultrafine OLED patterns.
The proposed technique does not require using fine-metal masks to structure thermally evaporated OLED stacks (“FMM-free”).
One of the main challenges when applying standard photolithography is the fragility of the organic materials for the photolithography chemicals.
To circumvent this issue, Imec and CPT have used an i-line, chemically amplified photoresist system in a process flow dedicated to OLED stacks.
Apart from ultra-high resolution, other benefits of photolithography include high aperture ratio, large substrate size compatibility and good yield control.
The proof-of-concept is a passive display with 1400×1400 pixels (1.96 megapixel) of side-by-side, orange and green OLEDs.
The sub-pixel pitch of 10 μm results in the equivalent resolution of 1250 ppi.
Uniform electroluminescence is demonstrated with the possibility to light up each color separately.
Preliminary lifetime investigation shows operation of each color after patterning for a few hundred hours at more than 50% of the original brightness.
Imec, and its development partner Chunghwa Picture Tubes (CPT) , aimed to push pixel density beyond 1000 ppi.
Imec and CPT have verified that a novel photolithography process can allow for ultrafine OLED patterns.
The proposed technique does not require using fine-metal masks to structure thermally evaporated OLED stacks (“FMM-free”).
One of the main challenges when applying standard photolithography is the fragility of the organic materials for the photolithography chemicals.
To circumvent this issue, Imec and CPT have used an i-line, chemically amplified photoresist system in a process flow dedicated to OLED stacks.
Apart from ultra-high resolution, other benefits of photolithography include high aperture ratio, large substrate size compatibility and good yield control.
The proof-of-concept is a passive display with 1400×1400 pixels (1.96 megapixel) of side-by-side, orange and green OLEDs.
The sub-pixel pitch of 10 μm results in the equivalent resolution of 1250 ppi.
Uniform electroluminescence is demonstrated with the possibility to light up each color separately.
Preliminary lifetime investigation shows operation of each color after patterning for a few hundred hours at more than 50% of the original brightness.
