High contrast markings by ultrashort pulse laser ablation

In the course of the constantly improving quality managment, insriptions such as the serial and the batch number, the place of manufacture, the production line or any other information are marked directly on the component the unambiguous traceability of the product. If in most applications, simple marking laser system are suitable for the labeling of the components, there are also marking applications where high structural quality, low surface area damage or special properties sucha s chemical resistance are required. For such applications the ultrashort pulse laser is suitable due to its outstanding properties. The component and the surrounding area of the inscription are not affected by the processing due to the almost absent thermal stress.Structure resolution in the range of single digit micrometers can be produced in any material without burr.

Requirement for a good readability is a constant high constrast between the inserted label and the surrounding material. Particularly in metalic materials such contrast can be produced by a functionalisation of the surface.

The production of so called Cone-Like-Protrusions at the surface can create a structure with a high and broaband light absorption, so that the surface appears dark or black.

In the case of plastics the marking can be made with different methods. The photochemical marking changes the properties of the molecules and by that the optical properties without damaging the surface. The result is a dark marking. For foaming, the plastic is locally melted. During the cooling process, gas bubbles are trapped in the material and reflect the light diffusely. This results in a bright marking. The ablation process formes a cavity; alternatively a layer is removed from the layer composite so that the layer underneath is visible.

A P P L I C A T I O N S

CONTACTM.Sc. Philip OsterTel.: +49 (0) 2407 55 55 5-24E-Mail: applications@pulsar-photonics.de www.pulsar-photonics.de

Figure 1: High contrast marking of a metallic surface by Cone like protrusions

Figure 2: Scanning electron microscope image of Cone like protrusions

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