Laser marking is rapidly replacing older product marking technology, especially for direct marking applications which aid in tracking and traceability. From medical devices to automotive and aerospace parts, part information is showing up everywhere, either in the form of human readable alphanumerics and barcodes or Data-Matrix™ codes. Laser marking is a fast, clean marking technology, which also has benefits like flexible automation, improved environmental profile, and low cost of ownership. There are a few different technologies out there - and the “best” one for your application depends on the kind of mark you’re trying to make, and the material you’re using.
The main laser marker choices out there are Ytterbium:fiber (Yb:fiber); Neodymium: vanadate (Nd:YVO4); green (532 nanometers (nm)); ultraviolet (UV); and carbon dioxide (CO2). Neodymium-doped yttrium aluminum garnet (Nd:YAG) is also available, but is an older technology largely replaced by one of the others listed.
Here are a few guidelines for choosing the best laser for YOUR laser marking application:
Yb:fiber gives you the lowest cost of ownership with great mark quality – The fiber laser marker is the latest and greatest laser design, and gets a thumbs up for high energy efficiency and low maintenance requirements. Fiber markers make high quality, contrasting marks on metals and plastics, engrave metals, and can machine a wide variety of materials. As an added bonus, they can be mounted in any direction, making them a highly flexible integration option. Fiber markers are also capable of fine cutting and micromachining.
Nd:YVO4 is your best bet for fine laser marking – If your application needs high resolution fine marking, with very fine detail or small character sizes, look no further: this one’s for you. With excellent beam quality and a minimum focused spot size of less than 0.001-inches (25 microns), it makes fine contrasting marks metals, plastics, and ceramics.
Use green laser markers for certain plastics, silicon and reflective metals – Lasers in the visible green spectrum provide increased contrast on plastics that don’t have pigmentation, the ability to soft mark silicon, and high quality marking of precious materials like gold and silver.
UV laser markers give you extremely high resolution/contrast for plastics and corrosion resistant marking –The UV laser marker’s 355nm wavelength provides excellent contrasting marks on many of the plastics other lasers are unable to mark, like medical tubing, and make highly reliable corrosion resistant marks on 17-X stainless steels.
Pick CO2 if you are marking printed circuit boards, paper or wood – This laser marker, operating at 10604nm wavelength, is great for marking organic materials, as well as printed circuit board (PCB) material and glass. Don’t use it for marking bare aluminum, copper or brass, or for producing quality marks on steels.
Nd:YAG is still a good option for large area metal marking and deep engraving – While it’s been largely pushed aside, Nd:YAG is still great for applications that need raw power (50-100 watts). Note that fiber laser technology is increasing in power, and is beginning to replace older Nd:YAG lasers as the technology becomes obsolete and for the significant reduction in the cost of ownership.
We’d love to hear your thoughts on the best laser markers for particular applications in direct part marking!