Abstract
The colorless polyimide (CPI) has been drawn much attention for its
application in transparent electronics, such as the camera under panel
(CUP) in organic light-emitting diode display (OLED) display which
required a high transmittance (Tr%). The high temperature (even to
450℃) process of the preparation of OLED device may have huge challenges
on the properties of CPI, so we designed a series of aging test
experiments to study the influence of test temperature and atmosphere on
the Tr% of CPI films with structure of Glass/SiO2/CPI/SiO2. With the
increasing of aging temperate from 430℃ to 450℃ and 470℃, the Tr% of
the film decrease obvious, especially responding the wavelength from
400nm to 600nm. The samples with aging test all had a low Tr% than the
sample without aging. Comparing with the sample without aging, the loss
transmission were 0.22%, 1.42% and 4.82% for the films aging with
430℃, 450℃ and 470℃ in N2 atmosphere, respectively. Meanwhile, the
influence of aging atmosphere on the Tr% was also researched with
nitrogen and air. The film aging with nitrogen had a higher Tr% than
that aging with air, the loss transmission were 1.22% and 1.42%
compared with the sample without aging test.