OSRAM ORBEOS Components - Manual (Page 15)

15
RELIABILITY
4.4. Robustness
In the following paragraphs, some indications are given on
the ruggedness of OLEDs and their stability against some
environmental conditions.
4.4.1. Mechanical pressure, shock and vibration
OLEDs are made of glass, meaning that mechanical forces
may cause glass breaks. One special case is local pressure
on the back side of a cavity-glass-encapsulated OLED. Even
with quite low forces (just by using a fi nger) the cap glass
may be bended and touches the cathode of the OLED caus-
ing damage to the device. Such handling must be avoided
during assembly of the OLED. For a thin-fi lm-encapsulated
device, this issue is irrelevant. OSRAM has tested various
OLEDs and their resistance against shock and vibration. The
table below shows the tested conditions. There is no concern
to use OLEDs under these conditions.
4.4.2. ESD sensitivity
OLEDs represent a big capacitance. However, they are not
designed for reverse operation. The organic layer structure
is very thin, meaning that high electrical fi elds can occur in
case of electrostatic discharge. According to the human body
model (HBM), OLEDs can withstand 1 kV. Proper grounding
should be assured when handling OLEDs during luminaire
assembly. In order to ensure maximum ESD stability, all
ORBEOS ® panels with fl ex connectors from OSRAM are
equipped with an ESD protection diode.
Test Condition Duration
Mechanical vibration Displacement: 0.35 mm
Acceleration: 5 g
Frequency: 10 – 500 Hz
10 sweeps per X, Y, Z direction
Mechanical shock 11 ms half sine
100 g peak
6 shocks per X, Y, Z direction
4.4.3. Low air pressure
The maximum ratings on the datasheet state 800 mbar as
minimum pressure. Actually, the OLEDs can withstand lower
air pressures, e.g. while transporting them on a plane. The
limit must be mentioned in case of glass-cavity-encapsulated
OLEDs. The glass cavity is fi lled with an inert gas at standard
ambient pressure. By decreasing the outer pressure, the dif-
ference between inner and outer pressure may cause a lift-
off of the cap glass from the substrate. However, the exact
values for the limit pressures change with the size of the
OLED. In case of a thin-fi lm-encapsulated OLED, this issue
is irrelevant.
4.4.4. Shelf life
Shelf life denotes the length of time a product may be stored
without becoming unsuitable for use. Under ambient condi-
tions (room temperature, 50 % RH, no direct exposure to
sunlight etc.) it is typically 10 years. Increased temperature
may reduce shelf life.
4.4.5. Photo degradation (UV resistance)
OLEDs are currently designed for indoor applications.