Substrate Curing Solutions
Curing is a common problem in processes which involve liquids and paste-like materials. These substances are usually applied onto a supporting material such as a glass substrate or a silicon wafer in the liquid phase. When subsequent processes require a "hardened" structure steps have to be taken to transform the liquid into the solid phase – these steps are usually referred to as curing. Unless the materials are not self-curing (e.g. two-component-adhesives) two major techniques have been established in the industry which is the curing by UV for polymerizing materials and thermal curing for solvent based suspensions. Totally different in the underlying physical principle both methods have to abide stringent limits in regards of high uniformity and stable process conditions to achieve repeatable, high-quality curing results.
Materials which are typically cured by ultraviolet light are adhesives, inks, resins and monomer based functional coatings. For optimal curing results accurate data on the material properties are essential in order to define the system required setup. Indispensable information includes UV-absorption spectrum, required intensity and irradiation time. MBRAUN offers in-house solutions specifically for the curing of epoxy-adhesives which are used in the encapsulation of OLEDs.
For thermal curing a range of process equipment, each with its unique advantages is available. From hotplates, oven vacuum furnaces, up to convection ovens - MBRAUN has dedicated solutions. Hotplates come into consideration when highest temperature uniformity across a large area is required. These systems are single-piece process stations and are available as stand-alone units or integrated into a stacker, for ambient operation and under vacuum as well as for manual or robot loading. Convection ovens are the tool of choice when larger batches have to be processed at ambient pressures under uniform temperature conditions. Specifically for the Flat Panel Display industry MBRAUN offers tailored solutions for stacked glass substrates. Vacuum furnaces are also needed when elevated temperatures up to 1500°C are required to achieve curing of materials with demanding properties.