| ID: | 3280 |
| From: | Gabriel Paubert <pa...@iram.es> |
| Date: | Sun, 18 Aug 2019 12:09:44 +0200 |
| Subject: | Re: [pcb-rnd] pcblib: parametric footprint script switchover: |
| in-reply-to: | 3279 from ge...@igor2.repo.hu |
| replies: | 3281 from ge...@igor2.repo.hu |
On Sun, Aug 18, 2019 at 08:26:40AM +0200, gedau@igor2.repo.hu wrote: > > > >On Sat, 17 Aug 2019, gedau@igor2.repo.hu wrote: > > > >>With keeping 100% backward compatibility, we will have some extensions, > >>mainly new parameters controlling aspects of padstacks that were > >>impossible to control with the old format. I will write separate > >>announcements about these when they are implemented > > > > After the pad_paste_ratio and pad_paste offs, the second set of > new features is about mask: > > 1. optional pad_mask_ratio, pin_mask_ratio > > When specified, mask opening size is copper size multiplied by this > number. > > 2. optional pad_mask_offs and pin_mask_offs (mm or mil) > > When specified, mask opening size is copper size plus this value > Nice, especially the second one, PCB manufacturers often want a minimum spacing around the pad (for NSMD pads), and it's the same parameter for well over 90% of my pads on most designs. > > Note: you need to use pad_* for the smd pads and pin_* for the > through-hole pins. Only the "normal" pads are affected, the (optional) > center pad (e.g. in a qfn) is a special case that has separate parameters. > > > If multiple sources try to set paste dimensions, the logic is as follows s/paste/solder mask/ > (same as for paste): > > 1. if there is a per footprint generator script value, we are going to use > that > > 2. else if there's an absolute value (pad_mask, pin_mask) for the paste > thickness, we use that s/paste thickness/solder mask opening/ > > 3. else if there's an offset (pad_mask_offs, pin_mask_offs), use that > > 4. else if there is a ratio (pad_mask_ratio, pin_mask_ratio), use that > > Because of the backward compatibility, we unfortunately have pad_mask and > pin_mask defined as default. This normally overrides the offs and ratio. > To start using the ratio or the offs, you also need to include a > pad_mask=- or pin_mask=- to cancel the default absolute value. (This is > unlike with paste, because we didn't have a hardwired default paste > absolue value to cancel). So a single "-" cancels (makes undefined or unspecified) an existing parameter, this may be a valid convention (especially for numeric parameters), but how generic is this? > > > Note: this feature is in the common code of parametric footprints, not in > pcb-rnd. Once the footprint is generated, the actual shape and size of the > paste is hardwired numerical data and does not depend on copper shape any > more. In other words these values affect how the generator works, but once > the footprint is generated, the paste shape becomes independent. However, > one can always change the parameter and re-generate the footprint and > replace the old with the new, in-place. > > Regards, > > Igor2 Regards, Gabriel
Reply subtree:
3280 Re: [pcb-rnd] pcblib: parametric footprint script switchover: from Gabriel Paubert <pa...@iram.es>
3281 Re: [pcb-rnd] pcblib: parametric footprint script switchover: from ge...@igor2.repo.hu