Laser cutting PCBs: The technology behind our depaneling machines

Different material combinations of FR4 composites can be processed with the laser without any problems. It is possible to achieve combinations of cutting edge quality and effective cutting speed that cannot be achieved with any mechanical cutting processes. In addition, the laser technology does not cause any mechanical stress in the material due to the non-contact functional principle, and there is no dust deposition on the surface due to the process, which could result in malfunctions.

In comparison to traditional separation methods, the laser process can be used to cut a wide variety of material thicknesses and compositions of flexible PCBs with maximum cleanliness, care and precision. In the process, the tool leaves no traces on neither the laser entry side nor the laser exit side that might have a bad influence on the quality of the substrate or the entire circuit board.

The main advantage of the laser process over the traditional mechanical cutting methods is the wear-free processing. It is due to the fact that extremely high hardness of the materials is not relevant for the laser ablation process. In addition, the use of lasers enables the clean cutting of complex structures of ceramic circuit boards and molded parts in various material thicknesses. The parameter settings of the laser allow the individual requirements of the ceramic circuit boards to be taken into account easily.

The solution developed by LPKF to meet the special requirements of IMS machining offers a lot of advantages. The benefits for the customer include the fact that the material is not mechanically stressed, no metal chips can be deposited and the cutting edge quality and effective cutting speed are correspondingly high.

There is a widespread prejudice that laser systems are expensive and not sufficiently cost-efficient. However, this assumption is now outdated, because the price-performance ratio of the systems has improved by a factor of 10 over the last decade. Consequently, laser systems are highly attractive for a very wide range of applications. Compared with milling machines, they are nowadays at a comparable price level in terms of investment costs and score particularly well for their low follow-up costs. There are no regular costs for wear parts such as milling heads or saw blades, there are inexpensive universal workpiece carrier solutions, and the material used can also be used much more effectively.

Another common prejudice is that the laser would burn or inevitably carbonize the PCB material. Here, too, the world now looks quite different: LPKF's CleanCut and Tensor technology in particular help to specifically control the heat input into the material. In this way, carbonization can be allowed or completely excluded, depending on the requirements. Even components very close to the cutting channel are not damaged by the energy introduced by the laser. External investigations for our systems prove that even 100 µm away from the cutting channel temperatures are measured that are far from damaging components.

A frequently asked question is also the speed of depaneling with the laser. This question can hardly be answered in a general way, but requires a more differentiated consideration. The speed depends on several factors: the laser variant, the type and thickness of the substrate, and the desired quality of the cut edge. Maximum speeds of significantly more than 50 or 60 mm/s are possible with 0.4 mm (FR4), as are effective cutting speeds of around 10 mm/s for blanks with 1.6 mm material thickness.