Discussion and summary
We explored how to quantify laser marking and surface texturing and use these techniques to laser marking aluminum. We have also developed techniques for marking more challenging copper and uncoated glass surfaces, and it is clear that there will be process applications for a wider range of surface structures in the future.
Laser welding between copper metals or with other metals has been a problem in the field of low power heat conduction welding because of the inherently high reflectivity and diffusion coefficient, as well as inconsistent native surface oxide layers. It turns out that this dark marking technique improves consistency when soldering copper. As part of ongoing research, laser beam is used to improve and standardize surface absorbance, and these fine structures can also enhance the bond between copper or aluminum and other different metals.
Figure 1: Marking on copper metal using an IPG pulsed laser
In the related case, the same sub-nanosecond laser was used to laser pretreat the metal so that it could subsequently be bonded to the transmissive polymer. The advantages of laser-cleaned surfaces, such as increased surface area due to laser pretreatment and localized laser heating, facilitate the combination of specific metal-polymer combinations to easily reach the strength level of the substrate.
Finally, the ability to diffuse or scatter light on optical surfaces using conventional laser scanning techniques is guaranteed. The application under consideration is to control glare, which in turn makes the processed object easier to see by the human eye. The performance-enhancing and cost-effective fiber lasers demonstrated here enable customers to move laser marking from low-cost applications to higher value-added marking and surface texturing applications.