> > FYI -- the largest dimension I ever did on a board was 54 inches. > >The largest board I've done in PCB was a quarter mile... I had a "my >house" element. It was tiny. > >But I was only testing pcb's limits at the time... > > > I couldn't say what the standard panel sizes are in the industry, > > but I could make an effort to find out. > >I'm guessing they're around 0.5 to 1.0 meter, based on the size of the >drill machines...
>To find out would probably require a few calls to some of the larger >PCB fab houses. If the drill machine were the ultimate limit, I >would think that would only limit one dimension. Even if the table >doesn't travel enough to cover the whole board, it can be >repositioned after the first pass. But you can't drill further into >the board than the machine will reach. I guess it may not be the >same as CNC work, but I've done this with my drill press a number of times. For flexible PCBs which are made on roll to roll machinery, the laser drills can make the required holes in a section, and then advance the web (roll) align to the previous holes, and continue. If they use a laser imager the same could be done on that step. All of the wet process steps are done roll to roll, so in reality you could make a continuous PCB thousands* of feet long. The main restriction is if their equipment could handle a gerber file that would need to be sectioned into hundreds or thousands of process steps (instead of their normal step and repeat). *The biggest constraint on roll length is how thick the rolls of material are when wound up, since the winding/unwinding machines have a diameter and weight limit. Andrew Miner _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
