Self-alignment-Vertical-alignment LCD technology
Improved processing and green technology
Easier production
PS-VA LCDs require a polyimide (PI) as an orientation layer to vertically align LC materials on the substrate. In the case of SA-VA LCDs, specific additives in the LC mixture ensure the vertical orientation. Consequently, the LC mixture takes over an additional function. A PI orientation layer is not needed.
All other following steps such as tilt angle adjustment with RMs are comparable to PS-VA.
The production of LCDs with SA-VA technology is becoming easier.
Benefits
- Green technology because no orientation layer is necessary, thus saving energy and reducing waste (orientation layer process)
- No interaction of PI material with LC material is possible. Potentially improves
LCD reliability. - Compatible with existing PS-VA production lines.
- Extremely narrow bezel LCDs are possible (no critical interaction of sealant
with PI layer). - Enables low temperature processes (compatible with heat-sensitive materials, e.g. plastic substrates, organic TFTs) by removing high temperature PI step.
SA-VA switching mode
In the “on” state, the major part of LC molecules are aligned parallel to the surface.
A small part is still aligned orthogonally to the surface due to strong interaction with RM/SA additive layer.