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ohjeita:design_rules [2015/04/08 00:22]
hrst
ohjeita:design_rules [2015/04/08 00:24] (current)
hrst
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 You can try to do stuff below these minimum limits, but yield goes down very quickly and you have to be extra careful. You can try to do stuff below these minimum limits, but yield goes down very quickly and you have to be extra careful.
  
-Annular ring is especially important in through-plated boards due to the tenting process - photoresist film must have enough area on all sides of the pad to adhere to, and you need to have extra for alignment mismatch. Sacrifice pad-to-pad / pad-to-track clearance on round pads to get larger pads - 6 mil / 0.15 mm clearance is doable in pin header / via rows.+Annular ring is especially important in through-plated boards due to the tenting process - photoresist film must have enough area on all sides of the pad to adhere to, and you need to have extra for alignment mismatch. Sacrifice pad-to-pad / pad-to-track clearance on round pads to get larger pads - 6 mil / 0.15 mm clearance is doable in pin header / via rows. If you can ensure 12-16 mil (0.30-0.40 mm) annular ring by doing that, it's all good.
  
 Use 18µm copper clad when you have used extended areas of 8 mil (0.20 mm) work to improve etching resolution. If you through-hole plate your boards, use 18 µm clad even with mainly 10 mil (0.25 mm) boards, because the plating increases the copper thickness by about 15 µm. Use 18µm copper clad when you have used extended areas of 8 mil (0.20 mm) work to improve etching resolution. If you through-hole plate your boards, use 18 µm clad even with mainly 10 mil (0.25 mm) boards, because the plating increases the copper thickness by about 15 µm.
 
ohjeita/design_rules.txt · Last modified: 2015/04/08 00:24 by hrst
 
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