Coherent has developed a new class of high power CO lasers with performance and reliability similar to the company’s CO2 lasers and average powers ranging from 60W up to 500W. The CO laser output wavelength is ∼5.5 μm, compared to 9 – 11 μm for the CO2 laser. Since materials have different absorption and light/material interactions at different wavelengths, the CO laser opens up new opportunities and applications for laser processing. Additionally, since the wavelength of the CO laser is only half of the CO2 laser, CO lasers can readily be focused to spot sizes ∼25 μm in diameter. This enables smaller hole drilling in a wide spectrum of materials such as glass, ceramic, and copper oxides used in printed circuit boards (PCBs).
This paper presents CO laser processing results in a variety of materials, and where possible compares them to what we’ve obtained with CO2 lasers. The small spot size shows advantages in ceramic drilling and scribing. We have successfully scribed 1mm thick ceramic (Alumina) with 40um spot size and 330um scribe depth. In addition, we have drilled through-holes with 60 um entrance diameter and taper less than 3% of the ceramic thickness (0.63mm thick Al2O3). These hole diameters are approximately half of what is normally achieved by CO2 lasers. We have also investigated cutting ceramic with the CO laser, and we achieved good quality with no dross or discoloration. Finally, the CO laser has been used to cut glass. We’ve been able to cut Schott 263T glass (0.2 mm thick) at speeds of 2000mm/s with multiple paths for both linear and curved cuts. These cuts show mirror-like cutting quality (i.e. high strength) and the cutting processing parameter window is wider than observed in CO2 lasers.
The CO laser is an exciting new technology that has significant advantages in a broad range of applications.