Benefits and Advantages of Engraving with Fiber Lasers

Laser engraving is a similar process to laser marking. Both use a fiber laser to produce a pattern, design, or another mark on the surface of an item, though there are subtle differences between them. We will explain these and then briefly explore the limitations of the more traditional engraving processes, including mechanical milling and photoengraving. Finally, we show how engraving with fiber lasers overcomes these limitations while also providing additional benefits.

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Engraving of Stainless Steel

Fiber laser marking and etching – what is the difference?

Laser marking implies a process in which a laser beam changes the properties of the substrate surface, producing sufficient disruption of the surface properties to leave a mark. The mark might be the result of surface oxidation, or in the case of an organic (plastic) substrate, surface carbonisation. Laser marking does not remove any significant amount of material.

Laser engraving, on the other hand, does remove material from the substrate, creating a cavity. It heats the surface to a sufficiently high temperature to evaporate some material from the surface. Different quantities may be removed for various purposes. For instance:

  • Light fiber laser engraving typically creates a trench of between 5 and 25 microns depth
  • Deep fiber laser engraving creates deeper trenches the maximum depth of which are dependent on the power of the laser beam and the optical absorption properties of the substrate

Now we understand the process basics, let’s look at its essential benefits and advantages compared with traditional mechanical and photoengraving.

Mechanical engraving

This involves moving a rotating milling bit or cutter over the surface of the substrate or workpiece. The rotating cutter removes the material surface. This method allows deep cuts to be made, but it has many limitations. For instance:

  • It is difficult to engrave fine details
  • Milling bits tend to wear rapidly needing frequent replacement
  • It isn’t suitable for all materials
  • It can be difficult to clamp the workpiece
  • It produces waste material that has to be removed from the workpiece

Photoengraving

The photoengraving process involves coating the surface with a photochemical polymer (photoresist), then exposing the polymer to light, selectively polymerising a pattern.

Next, the polymer is thermally cured, and the exposed or unexposed regions of polymer (depending on whether a negative or positive photoresist process is used) are dissolved away. The exposed areas of the substrate are engraved using a chemical etchant, reactive ion beam, or a plasma.

Unlike mechanical engraving, this process can be used to engrave fine details. It is used extensively in the semiconductor industry in the manufacture of silicon wafers, but it also has limitations for many industrial processes. For instance:

  • It is a relatively expensive process requiring expensive equipment
  • It isn’t suitable for all materials
  • The resist process has many restrictions and can’t be used in many industrial applications
  • Many of the chemicals used are dangerous and harmful to the environment

Fiber laser engraving overcomes the limitation of both mechanical and photoengraving while providing many additional benefits, as shown below.

Fiber laser engraving is a non-contact process

Fiber laser engraving is a non-contact process. This eliminates collateral damage that may be caused by mechanical tooling. There is nothing to wear out, so the engraving pattern is highly accurate and repeatable. Even areas of the workpiece that are difficult to reach mechanically can be engraved by a focused fiber laser beam.

A wide range of depths is achievable

Depending on the laser absorption characteristics of the workpiece material, by adjusting the laser properties trenches as fine as a few microns can be produced while it is also possible to create channels of varying depths depending upon entry width and time requirements (e.g. the image shown above is engraved at a depth of 1mm).

Can be used on many different materials

Fiber laser engraving can be used for a wide range of materials, including metals such as copper, aluminium and steel, and latex rubber; plastics such as Bakelite, and specially formulated polymers; ceramics and silicon.

High process efficiency and quality

Fiber laser engraving is a rapid process that readily lends itself to robotic manufacturing. It is also high yielding, as there is no gradual fading of engraving quality. As fiber lasers require minimal maintenance downtimes are very much reduced.

Energy efficiency

Compared to CO2 lasers, fiber lasers are much more energy efficient. Typically, they will use three to five times less electrical power.

Health and safety benefits

As no toxic chemical by-products are produced, the process is far less damaging to health and the environment.

An environmentally friendly process

Chemical etching and plasma processing produce many environmentally damaging materials, some of which are difficult to deal with and require special treatments before releasing to the environment.

Fiber laser engraving is used in a wide variety of industries for many applications

The many different applications of laser engraving include:

  • Aerospace for labelling parts with barcodes and serial numbers
  • Automotive industry for engraving of vehicle identification numbers (VIN) and other identification codes
  • Security and banking where it is used for marking credit cards and other valuable documents
  • Semiconductor and electronics industries for engraving traceability data
  • Medical for engraving surgical instruments
  • Jewellery for engraving hallmarks and personal messages
As can be seen, semiconductors have many engravings in them

As can be seen, semiconductors have many engravings in them

Further information about laser engraving

In this short brief, we have barely scratched the surface of the multiple benefits and advantages of engraving with fiber lasers, but at least we hope to have given you a flavour of what is achievable and how switching from alternative processes may improve your profitability and productivity. If you would like to explore any of these or features in more depth, including how they might be applied to your current challenges, just call or message us. Here are our contact details.

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