The fact that LEDs are used in smartphones and tablets, as well as different types of displays and sensors, should be well known. It may not be as well known that they are widely used behind the scenes. In manufacturing processes, LEDs with a special wavelength range (i.e., UVA LEDs with wavelengths from 365 nm to approximately 400 nm) play a role.
UV LEDs Used to Cure Touchscreens
UVA LEDs are used to cure adhesives; for example, touch-sensitive screens are assembled by bonding together the display glass, touchscreens, and LCD displays across the entire surface.
When smartphones first came out, the touchscreen and display were stacked on top of each other without a surface adhesive – air was sealed between the layers. As the screens got larger, framing and pressure distribution became more difficult.
Full-surface adhesion became an integral part of production. This has made it possible to produce flatter and flatter smartphones, as well as to produce and assemble them more quickly and in an uncomplicated manner [1].
Curing of Other Adhesives
UVA LEDs are also used to cure DVDs, automotive electronics, and cabin equipment in airplanes. Another prominent example is the curing of laminate flooring.
Also Ideal for Varnishes and Printing Inks
In addition to adhesives, varnishes and printing inks also need to be cured. These substances start out as a liquid and are solidified via a chemical reaction brought about within a matter of seconds by the high-energy radiation of UVA LEDs [2]. UVA LEDs are also used in the dental industry to cure composite fillings in teeth. Activating an initiator at a wavelength of from 300 nm to 450 nm triggers the polymerization of the composite and the curing of the filling [3].
UV LEDs in lieu of UV Lamps – The Advantages:
LEDs continue to replace UV lamps and flash lamps in these applications. The reasons for this are multifaceted:
- UVA LEDs have a longer lifetime, typically >10,000 hours
- LEDs feature short switching times because they do not need to warm up
- LEDs require very little space
- The heat radiation of UV LEDs is minimal
UVA LEDs up to Four Watts
We offer UV LEDs used in the curing of adhesives, varnishes, and printing inks, as well as in special illumination systems.
Whether packaged in an SMD with or without a lens or as a chip, we have the following wavelengths available as part of our product range: 365 nm, 385 nm, 395 nm, and 405 nm.
With an output power of up to 4 W, a long lifetime, and a compact design, UV LEDs form the basis of technologically-advanced high-end products in industrial applications.
[1] www.iphone-support.de/wissens-wiki/displayvollverklebung/index.html
[2] de.wikipedia.org/wiki/Strahlenh%C3%A4rtung; Version vom 02.02.2015
[3] de.wikipedia.org/wiki/Komposit_%28Zahnmedizin%29; Version vom 02.02.2015
