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Touchscreen Manufacturing with UV LED Curing Technology

Ultraviolet (UV) light-emitting diode (LED) curing offers many benefits for bonding and coating applications in the touchscreen manufacturing segment. It provides a more consistent and reliable process without damaging or discoloring heat-sensitive components.

UV curing is a photopolymerization process that uses UV energy to change a liquid to a solid. Upon absorption of the UV energy, the photoinitiator (PI) produces free radicals that initiate crosslinking with binders (monomers and oligomers) in a polymerization reaction to cure or solidify the ink, coating, or adhesive, usually in a few seconds.

The touchscreen market continues to grow; uses include smart phones, tablets, eBook readers, mobile game consoles, and in-car navigation systems. Asia-Pacific is the largest and fastest growing regional market for touchscreen manufacturing.

A touchscreen display is an assembly of many different layers, such as the liquid crystal display (LCD) or organic light emitting diode (OLED), glass, conductive and non-conductive layers, and a protective flexible layer. Each of these layers needs a liquid optically clear adhesive (LOCA) to provide a strong bond, a protective seal from moisture, and desirable optical properties while withstanding sunlight.

UV LED curing technology provides a more consistent and reliable process without damaging or discoloring heat-sensitive components.

UV LED-curable adhesive formulations are typically acrylic or epoxy cured at 365 nm, and deliver excellent optical properties such as light transmission, reduced reflections, anti-fogging, and impact and scratch resistance. They are easy to dispense and provide high flexibility without shrinkage or tension between layers, which could cause image distortion.

UV LED curing offers electronics manufacturers higher yield rates and productivity due to a consistent and stable process with less damage to heat-sensitive components. UV LEDs require very little space, making them easy to integrate into small spaces. Since UV LEDs produce no ozone emissions or hazardous waste concerns, they are environmentally friendly and safe.

Electronics adhesives and coatings suppliers have formulations available for use with UV LED curing that are easy to handle and apply in the precision, high-speed processes that are so common in electronics manufacturing. Many electronic product manufacturers are already reaping the benefits of using UV LED curing to improve their manufacturing processes.