What Is the Difference Between Laser Cutting and Etching?

Visually it is very simple to recognize a laser cut part from a laser etched one. A laser beam is like a super-powered cutting tool so picture using it on stainless steel or perhaps polyimide or other materials. If you hold the beam steady and let it burn for a while, you’ll cut a clean hole right through – that’s laser cutting. Laser etching, on the other hand, is more like using a fine-tipped pen to draw on the surface. The laser beam moves quickly and focuses its heat on a very small area, vaporizing just a thin layer of the material. This creates a visible mark or image, but it doesn’t go all the way through. It’s like toasting the top layer of bread without burning it. One will be a single part or component, while the other will alter the surface leaving a mark. Laser cutting and laser etching sometimes will go together during precision laser services manufacturing. There are times for example that the cut parts need to be marked with a lot or part number. This information is helpful in any future necessary maintenance or repairs by allowing identical parts to be used. Laser etching is not a process that involves any additive inks or coloring. The mark is the ablated surface and will vary in contrast per the material being etched. A good example of this is laser etching anodized aluminum. The anodized coating when ablated, will result in a very contrast color of white text or other nomenclature. It does give a handsome appearance to the finished part and is good for logos and other creative imagery. For laser etching PCB material such as FR4 or Rogers, the laser will ablate the surface, often used for parts numbers. The contrast will be light and not very visible. This is solved by manufacturers rubbing white or black ink into these recessed areas. This results in readable text but does add more time and labor costs.

Laser cutting of polymers, metal alloys, adhesives of even PCB laser cutters are very different in the results that are achieved than laser etching and while both have specific uses in manufacturing, not all materials and projects can have both processes applied. An example of this is laser cutting Kapton that cuts very well on the UV laser spectrum. Many projects require ultra-thin gauges of Kapton from 0.0127mm to 0.0254mm thick. Cutting is fine, but laser etching is challenging as any incorrect setting might cut the defined text through instead of resulting in a surface mark. This is also true for ultra-thin gauges of metal alloys like stainless steel, nickel, copper, tungsten and so on. When presented with a project for cutting and etching of thin gauge materials, manufacturers may recommend other methods like labeling or ink stamping if needed. The key difference lies in the depth and intensity of the laser’s interaction with the material. Cutting requires high power and a longer dwell time to completely vaporize or melt through the material. Etching uses lower power and a faster movement to just “mark” the surface. I hope this analogy helps visualize how these processes, though similar, achieve very different results.