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78 PCB007 MAGAZINE I JUNE 2024 minimum. Sometimes, you need that 17-foot wall; just be prepared to pay for it. Why Standard Panel Sizes? ere have been many automation tech- niques developed over the past several decades in the circuit board manufacturing industry. In the late 1980s, raw materials were almost exclu- sively processed manually. An operator would cut panels from their original roll or sheet and manually place them in drill stackups consist- ing of drill entry and backer boards. ey were then pinned individually to the bed of a sin- gle-spindle drill. Panels were manually racked and placed in hoist systems on a copper plat- ing line. Once plated, panels were manually coated with photoresist and printed on bed printers. A bed printer consists of a glass vacuum bed with a hinged mylar frame. Negatives were aligned to the panel and placed on the glass printing bed. e hinged frame was closed, and operators pulled a vacuum. e top sur- face was sprayed with glass cleaner. ey then used a squeegee in a forward-and-back motion while applying as much downward force as they could muster. is was done to ensure a clean surface, as well as a tight mylar seal to the coated panel prior to imaging with high-inten- sity light. I'm certain that surgeons specializ- ing in carpal tunnel procedures benefited from the archaic, repetitive nature of this process. A walk through the print room generally came with the observation that at least one person would be wearing a wrist brace or two as a form of industrial jewelry. Following imaging, an operator would place panels on the conveyor of a developer, an etcher, and then a resist stripper. In some instances, one or more of these processes are still done manually as manufacturers decide how and when they choose to automate. At this most basic level in flexible circuit processing, we quickly see the importance of automation. A simple equation would be Task + Operator = >$ (increased costs). Things Have Changed In a modern flex and rigid-flex fabrication facility, raw materials are now picked up auto- matically or indexed to allow for an automated panel size creation. A stack of panels is placed in front of a drill, where it is picked up and drilled on a six-spindle drill. e stack of drilled pan- els is then placed in front of a hori- zontal plating line where it is placed on the conveyor by a robotic arm. is is done at precise angles and spacing between panels for optimal efficiency. At the end of the line, the panels are picked up from the conveyor and restacked. e stack then moves its way to the front of a resist coater, where a robotic arm picks it up and coats it with photoresist, creating a contin- uous roll of photoresist-coated pan- els. is roll of material is cycled through a machine that pauses and images them precisely and accu- rately. e machine may need some routine preventative mainte- nance, but it is much less invasive, Automation is key in handling flexible circuit materials.