The difference between the infrared laser and UV laser in industry application
Author: Maiman LaserTime: 2017-09-27
Both Infrared lasers (IR laser, including YAG, fiber laser and Co2 laser) and ultraviolet lasers (UV laser) are widely used in industry, what is the application difference between these two lasers? And which laser is better for laser marking?
To select a right laser, it is necessary to understand the basic working principle of laser processing materials:
Infrared laser (Co2 laser and fiber laser):
The substance of the material surface is heated and vaporized (evaporated) by laser, this way, the material removed, this approach is often referred to “thermal processing”.
High-energy UV photons directly destroy the molecular on the surface of the material, this way, molecules removed, the process does not produce high heat and it is called “cold processing”.
The material processing principle determines the difference in the application of the two lasers:
Infrared lasers applications:
Infrared lasers, including Co2 laser, diode laser and fiber laser is the most widely used laser source for materials processing, those lasers applicable to all kinds of metal, organic and most of the plastic laser processing.
But, many plastics and special polymers (e.g., polyimide) cannot be fine processed by infrared laser or by the so-called “thermal processing”, for example, flexible printed circuit board base material (FPC), thermal processing makes plastic deformation, plastics carbonized at the edge of the cutting or drilling, and this leads to structural weakening and additional conductive path, It requires subsequent treatments to improve the quality, hence, infrared lasers are not suitable for flexible circuit processing.
In metal laser applications, infrared laser beam energy cannot be absorbed by copper even at high energy densities, this limit infrared laser application in some extend.
UV laser applications:
Unlike infrared laser “thermal processing”, UV laser processing use high energy photons to damage molecular bond of non-metallic materials, the processed work-pieces have sharp edges and minimal carbonization.
Moreover, the UV laser has a very small focus spot size in submicron level, this makes laser micro processing and fine parts laser processing possible, and a high energy density can be achieved even at a low pulse energy levels, the possibility of material processing greatly improved. A typical application is tiny holes laser drilling.
We can conclude that UV laser has an absolute advantage in ultra-fine marking, special materials marking since UV laser has a small beam spot size and heat affected zone, as UV lasers become more mature and stable, UV lasers are widely used on silicon wafers, circuit boards, sapphire phone screens and plastic processing, but compare with infrared lasers, UV lasers have a high cost, relatively short life time and high failure rate.
Infrared lasers (including Co2 lasers, diode lasers and fiber lasers) have been widely used in all kinds of sector sectors, they have a great advantage of matured, stable and low investment, and this makes they are still the first choice for traditional industries.