A study on crucible inner pressure change during degradation of liq in amoled mass production

We developed crucible inner pressure sensor for evaporation source that is used widely in AMOLED mass production. It can be installed at crucible and can directly measure crucible inner pressure without contamination. We tested the degradation of Liq by using inner pressure sensor. And we found unexpected increase of crucible inner pressure during degradation of Liq. We assumed that it is caused by released gas during degradation. We studied on degradation mechanism by using RGA and 1H NMR and found out the gas is hydrogen that is produced from Liq during degradation process. We think this behavior of inner pressure during degradation can be used as alarm signal for preventing loss in AMOLED mass production line.