Issue link: https://iconnect007.uberflip.com/i/1536435
20 PCB007 MAGAZINE I JUNE 2025 A common technique is to redistribute the energy of this beam profile to a more suitable beam profile. In the PCB industry, everyone wants a circular hole with sharp edges, and in the center there should be a homogeneous amount of energy applied so that the copper is not more penetrated in the center than on the edges. On the target, you want a top-hat beam profile with sharp edges and a flat top in the center. Shaping the beam from a Gaussian beam profile to a top-hat enables you to create a sharp taper of the microvia, as well as creat- ing less damage to the target copper. In com- bination with the benefits of the picosecond laser, it is perfectly suitable for overhang-free micro vias in a high density layout. Depending on the application, we have our standard beam shaping technology for vias between 10 and 50 µm, and starting just this year, we have added what we call Schmoll Advanced Beam Shaping, also using picosec- ond technology. is allows us to make an even more homogeneous flat top in the cen- ter with sharp edges. e size range is from 75 microns at the top to 30 microns at the bottom. We are creating circular holes with a really good taper. Typically, we are reach- ing 80 to 85% taper there. is new approach is optimized to fulfill current requirements towards SAP and mSAP technology You would only use the beam shaping if you're doing the very small holes, 3 mils or below? Exactly. Otherwise, we can do a homoge- neous accumulated energy profile by deflec- tion. Let's say these hole sizes, 3-mil and below, are systems with thin (<12 µm) or no copper on top, and have fiber-based mate- rial, fiberless material, or ABF. is picosec- ond pulse laser is perfectly suitable, using our advanced beam shaping technology on these holes. is is necessary. If a hole gets smaller and you keep the taper at 70%, the target pad will be too small for the plating process. Everyone wants to go into (outer) space now. ere's a lot of stress on the vias, right on these con- nections. With vias getting smaller, we have to increase the taper to have more area for good bonding on the bottom, for better reli- ability, and definitely for thermal stress. We must have a good foundation for the plating at the end. Stefan, this has been very interesting. Do you have any closing thoughts before we wrap up? For many of our customers, this is new tech- nology. e investment for a new laser sys- tem is quite high, so we oen offer courses and lectures that cover the basics. We want to encourage and enable this technology because we see what's possible. We want to transfer this knowledge so our customers can use the machines for current and future appli- cations that are not even on their radar yet. Stefan, thank you for your time. ank you, Marcy. PCB007 Dr. Stefan Rung