Thin-film getter integration is one of the key technologies enabling the development of a wide class of MEMS devices,
such as IR microbolometers and inertial sensors, where stringent vacuum requirements must be satisfied to achieve the
desired performances and preserve them for the entire lifetime. Despite its importance, the question about lifetime
prediction is still very difficult to answer in a reliable way. Here we present an experimental approach to the evaluation
of lifetime, based on an accelerated life test performed varying both the storage conditions and the getter area. A test
vehicle based on a resonator device was used. The hermeticity was evaluated by means of specific leak testing, while
MEMS behavior during the ageing test was studied monitoring device functional parameters and by residual gas analysis
(RGA). Unexpected results were observed leading to the discovery that methane is pumped by the getter below 100°C.
These results served as the inputs of a suitable model allowing extrapolating the device lifetime in operating? conditions,
and pointed out that RGA is an essential tool to correctly interpret the aging tests.
Moisture permeation is widely recognized as one of the most important causes of degradation in time of the
performances of photovoltaic modules, especially thin film ones. B-Dry®i is a newly developed edge sealant tape which
is able to block moisture penetration into PV modules for thousands of hours in Damp Heat Test (DHT) conditions,
thanks to the presence of a getter material. Visco-elastic behavior, even at relatively high temperatures, makes B-Dry®
especially suitable to guarantee mechanical stability of PV modules operating in hot and humid climates.
In many MEMS applications the level of vacuum is a key issue as it directly affects the quality of the device, in terms
of response reliability. Due to the unavoidable desorption phenomena of gaseous species from the internal surfaces, the
vacuum inside a MEMS, after bonding encapsulation, tends to be degraded, unless a proper getter solution is applied.
The in situ getter film (PaGeWafer®) is recognised to be the most reliable way to get rid of degassed species, assuring
uniform, high quality performances of the device throughout the lifetime. Moreover, post process vacuum quality control
and reliability for hermetic bonding is extremely important for overall device reliability and process yield. In this paper
we will discuss the main factors that are critical in the attainment of vacuum and will present a novel calculation model
that enables the prediction of vacuum level after bonding, making also possible the estimate of the lifetime. Furthermore,
a new analytical method based on the residual gas analyses (RGA) will be presented that gives the main characteristics
of the materials. Modeling and simulation work support the process optimization and system design.
In OLED organic layers electron injection is improved by using alkali metals as cathodes, to lower work function or, as dopants of organic layer at cathode interface.
The creation of an alkali metal layer can be accomplished through conventional physical vapor deposition from a heated dispenser. However alkali metals are very reactive and must be handled in inert atmosphere all through the entire process. If a contamination takes place, it reduces the lithium deposition rate and also the lithium total yield in a not controlled way.
An innovative alkali metal dispensing technology has been developed to overcome these problems and ensure OLED alkali metal cathode reliability.
The alkali Metal dispenser, called Alkamax, will be able to release up to a few grams of alkali metals (in particular Li and Cs) throughout the adoption of a very stable form of the alkali metal.
Lithium, for example, can be evaporated “on demand”: the evaporation could be stopped and re-activated without losing alkali metal yield because the metal not yet consumed remains in its stable form.
A full characterization of dispensing material, dispenser configuration and dispensing process has been carried out in order to optimize the evaporation and deposition dynamics of alkali metals layers.
The study has been performed applying also inside developed simulations tools.