Should kicad not impose 2 layer restrictions on blind/buried vias? That way users could at least use them, but will have to manually be careful since DRC doesn't support it. There could be 2 blind/buried vias on top of each other vertically, but on different layers and not touching. And have unlimited adjacent layer selection, from<->to.
If it's limited to 2 layers, users wouldn't be able to properly use blind/buried vias. On Sun, Jan 7, 2018 at 6:01 AM, jp charras <[email protected]> wrote: > Le 06/01/2018 à 22:58, kristoffer Ödmark a écrit : > > I am implementing it now, just a question, what should be the logic > behind micro vias? Not very > > familiar with those. > > > > Can they go between any number of layers, or only adjecent ones? I will > treat them like buried vias > > currently, so that they can go between any two layers. > > Micro vias and buried vias have constraints. > These constraints are highly dependent on board makers but usually these > vias cannot go between any > two layers. > > micro vias are in fact laser drilled vias, and the hole is not a cylinder, > but a cone. > the max depth (Z dimension) depend on the hole diameter. > If we restrict laser drilled vias to 2 adjacent layers, it should work in > any case (although a bit > restrictive). > This is one of reasons in Pcbnew microvias are only blind vias restricted > to adjacent layers. > More than 2 adjacent layers is certainly possible, but only the board > house can say that. > Of course standard blind/buried vias have also limitations, and cannot go > between any layer pair. > > For instance, see > https://www.eurocircuits.com/blog/blind-and-buried-vias/ > and > https://www.pcbcart.com/pcb-capability/blind-and-buried-vias.html > for limitation examples. > > And keep in mind limitations depends on the board house that will make > your board. > > Currently, Pcbnew is missing a layer stack manager (coming for V6), and a > dialog via properties > cannot safely manage the layers pairs of non through hole vias. > > Also keep in mind changing a via setup should be tested by the DRC > (clearance test) and the ratsnest > rebuild if layers change (or if the size is smaller). > > -- > Jean-Pierre CHARRAS > > _______________________________________________ > Mailing list: https://launchpad.net/~kicad-developers > Post to : [email protected] > Unsubscribe : https://launchpad.net/~kicad-developers > More help : https://help.launchpad.net/ListHelp > -- Remember The Past, Live The Present, Change The Future Those who look only to the past or the present are certain to miss the future [JFK] [email protected] Live Long and Prosper, Andrey
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