A Short Guide to Basic Laser Processing Techniques

Laser technology is already so commonly used in everyday applications these days that it is basically taken for granted. However, if one thinks about it, many aspects of life today were simply not possible decades ago because there were no lasers yet. Tasks such as playing optical discs, performing needle-less surgeries, or surveying vast areas of land were all made possible because of lasers.

Laser technology is something that has truly impacted human life in the fields of medicine, telecommunications, infrastructure and many others. Specifically, in the manufacturing industry, lasers have evolved by leaps and bounds to bring the benefits of efficiency, accuracy and reliability.

Laser processing

There are certain stages of manufacturing where laser processes are vital, and these include the machining of workpieces. In such a process, the workpiece is usually set on a linear stage so that it can be easily moved about or maneuvered under the laser to accomplish the laser processing task required. The positioning can also be accomplished in reverse, with the laser device being mounted onto the linear stage so that it can be moved over the workpieces that need to be machined.

There are many laser processing techniques that are applied on many different types of products and items. Laser cutting, for instance, traces an outline of a template onto a material (usually a flat sheet of of metal, plastic or wood) and produces the desired cut-out shape. Laser drilling is another similar process where pre-determined holes are bored through the materials.

These laser processes are usually employed when manufacturing individual parts for product assembly later on. They take the place of traditional mechanical or handheld tools such as saws, cutters and drills, which may be risky or dangerous for human operation.

Marking, etching and engraving

The processes of laser marking, etching and engraving are similar but they have a few differences. They all involve contact of a laser with the surface of a material, but they differ in terms of altering the surface of the material—depending on the depth of contact of the laser.

Laser marking is mostly used to create points or lines on a material. Roughly put, it is similar to making pen or pencil marks on paper to act as guide or outline for other processes later on, such as cutting or assembly. In this process, the laser is usually a low-power beam that discolors the surface of the material to produce a visual contrast, but leaving the surface intact and unaltered.

In laser engraving, the beam produces high heat with which to physical disrupt the surface of the material—zapping or vaporizing it to create a cavity or deep recess that is visible to the eye and felt by touch as well. Deep engraving—from 0.020” up to 0.125” depending on the material—is achieved by repeated process, until the desired depth is achieved. Laser ablation is another option to achieve this, where more surface material is removed.

Etching is a type of laser engraving where the surface material is treated just enough to melt, such that it reforms with a raised surface when it cools and expands afterward. The mark created is less deep, as etching takes away only around 0.001” of surface material.   

Benefits of laser processing

Many laser processes are used in the manufacturing industry for parts identification and marking. This makes product assembly faster, more efficient and more foolproof. It also enables easier product after-sales servicing. Some industries also etch or engrave parts and products with serial numbers for security and control purposes, or etch patterns on semiconductor wafers.

Many other industries also find great use for these laser processes. In the diamond trade, for instance, polished and cut stones can now be etched for identification and control against illegal or “blood” trade. The medical field is another industry where laser processes are valuable in identifying things, from large equipment down to micro components and implants for the human body.

As laser technology continuously evolved and improves, it will certainly find more use and applications in more and more areas of daily life. It is important to understand and gain even just a little insight into how this innovation works, so it may be utilized better and more effectively.