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I am currently using several footprints in my pcb design which have tPlace silkscreens that extend beyond the board boundaries, and I was wondering what the implications of such silkscreens are since they are not cropped up in the resulting gerber files? Will a PCB shop normally disregard any design elements that hang beyond the board boundaries, or will these silkscreen elements cause issues in board layout, either artificially extending the board dimensions or causing problems at the board shop where my silkscreen overlaps other boards?

I am using the tPlace elements of other components on the board to determine the orientation of various smd devices, so I don't want to simply remove the tPlace layer from the cam job.

Is there any way that I can crop these tPlace entities without manually editing the individual footprints, or does it matter at all?

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  • \$\begingroup\$ I figured out that I can also compensate for this, just in case overhanging silkscreens do matter, by opening up the gerber file in gerbv and deleting the offending silkscreen. This may be my solution for now. \$\endgroup\$ – Cyronin Aug 3 '12 at 17:09
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    \$\begingroup\$ You accepted within 15 minutes of asking your question, which is way too fast. Questions with accepted answers get less new answers, which could have been interesting as well. We suggest to wait a day or so, so that the question went around the world, and accept then the answer which best solves your problem. Just don't forget to come back here. :-) \$\endgroup\$ – stevenvh Aug 3 '12 at 17:18
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    \$\begingroup\$ Shops I've worked with have no problem doing lots of cleanup on the silkscreen, mostly to remove silkscreen features from pads or other exposed metal areas. I imagine they would not have a problem removing silkscreen from outside the board boundaries. To be sure they know what you want, just put a note in the fab drawing explicitly giving them permission to do it. \$\endgroup\$ – The Photon Aug 3 '12 at 21:24
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Your final DRC before creating the Gerbers should give you errors for them. Your PCB shop will also perform a DRC before starting production, and should give you a call about it. There may have been an error in creating the Gerbers, and they should check. I wouldn't appreciate it if my PCB shop will discard the overhang without consulting me, like Nick says.

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PCB fabs usually will clip/ignore the silkscreen which extends beyond the outline of the board in the Gerbers. The 3 fabs, which I've worked with, did this by default without me even asking.

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  • \$\begingroup\$ Thanks, while I have not selected a shop yet for the design (while keeping the drc as generic as possible), a little searching showed that at least olimex "might" have a few issues with overhanging silkscreens. This is good to hear though. \$\endgroup\$ – Cyronin Aug 3 '12 at 17:13
  • \$\begingroup\$ Among the fabs I was using are AdvancedCircuits and PCBExpress/Sunstone. I haven't worked with Olimex, though. \$\endgroup\$ – Nick Alexeev Aug 3 '12 at 17:38
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I never had any problems with silkscreen that extends beyond board dimensions. But I guess the way that is handled depends on the PCB manufacturer, so just to be sure you should contact your PCB manufacturer in order to verify if there is a problem with that.

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