Direct write machining provides a useful way of generating large cutout features and performing high volume hole drilling in materials where UV excimer laser fluence requirements limit spot size. By utilizing a CAD/CAM programming interface, required features can be drawn in CAD and then directly translated into motion control code without laborious manual transcription. Features can be drawn on different layers to facilitate automatic mask changes or changes in laser pulse spacing within a single process program. Points can be placed in the drawing to trigger step and repeat drilling operations, while lines and arcs generate profile cuts. Drill marker points can be drawn on different layers within the CAD file, enabling drilling depth control.
It is important to interpolate laser firing with the X,Y table feed rates to maintain good cut depth control. Using motion control to trigger laser firing is one way to achieve this result.