The Vapour Permeability of Optoelectronics, OLEDs and LCD Screens
The latest generation of flexible light-emitting diodes (OLED) displays, LCD screens and other optoelectronic elements are extremely susceptible to degradation from both moisture and oxygen. Creating efficient protection against these vapours has become a decisive factor in producing products with an acceptably long working life. Vapour permeability has been a limiting factor, particularly in the introduction of flexible OLEDs into consumer (and other) products such as mobile phones, tablets etc..
Because improvements, particularly in PECVD (Plasma Enhanced Chemical Vapour Deposition) technology, are leading to the creation and use of new and improved materials and manufacturing techniques in thin film encapsulation, it has become crucial to characterise the vapour permeability of the layers that make up the encapsulation both individually and as a compound multi-layer structure. This is true during both the product development cycle and for QC for manufacture.
This problem is sometimes resolved by the use of polymeric substrates with multi-layered barrier coatings comprising alternating organic/inorganic layers but it is critical that the vapour permeability of each layer and structure is accurately determined and controlled.
We have developed techniques and instrumentation that allows developers to measure the vapour permeability of these advanced new coatings both individually and as compound structures. Independent measurements can easily be produced relating to both water vapour and oxygen permeability. The equipment can also be used for detecting the occurrence of defects such as the pinholes that commonly are produced by current manufacturing techniques.
Our equipment offers an advanced, fast and efficient way to test and measure vapour permeability of alternative plastic barrier films along with the sealants used for permanent closure. The system is simple to use, fast and extremely accurate.
Results are typically accurate in the Parts Per Million (PPM) range (PPB in some cases and can be produced for several vapour depositions, material samples, screens or enclosures all at the same time. It can also measure them under a wide range of environmental conditions.
Click here for a press release on protecting OLEDs and flexible screens from the damaging caused by O2 & H20 vapour diffusion
Click here for a press release on LCD screens
Click here for a paper on Moisture Permeability Through Multi-layered Barrier Films as Applied to Flexible OLED Display