Advanced motion concepts for high-precision laser drilling

Key electronics and semiconductor manufacturing technologies require laser processing vertical high-aspect ratio holes. Laser-drilled vias in flexible and rigid PCBs are found in most electronic devices. Semiconductors recently adopted heterogeneous integration techniques with glass interposers requiring high-density through glass vias (TGV) manufactured via ablation or laser-induced deep etching (LIDE).   

Both application areas leverage a common motion trajectory primitive — step and settle. Step and settle moves are predicated based on the motion system’s ability to move the laser spot from one fixed position to another as quickly as possible and fire the laser only after the motion system has settled to within the desired tolerance. The desired time to move from hole to hole and fire the laser is typically measured in tens or hundreds of microseconds. High-density PCBs or glass interposers have tens of thousands of holes, making drilling time critical to overall production throughput. As the via diameters and space between them decrease for existing and emerging applications, the dynamics and precision for positioning the beam at each hole location becomes more critical. As the via diameters decrease and via hole density increases for next-generation applications, decreasing step and settle times will be vital for viable production processes.

This presentation will discuss, in detail, advanced motion concepts for making laser drilled vias  that not only drastically reduce step and settle times for laser scan heads performing the step and settle motion, but also challenge common conventions associated with machine design concepts for this process. This is done in an effort to enable the next generation of electronic and semiconductor devices to be manufactured at scale without sacrificing quality requirements.