Thanks for the clarifications. I will commit that shortly.
On Sun, Jun 8, 2014 at 11:35 AM, Jean-Paul Louis <lou...@yahoo.com> wrote: > Let’s get back to the basics. > > WHY A SILKSCREEN? > > Originally, PCB were assembled by hand, and the markings were dual > purpose, Assembly and Inspection. > They were printed on the PCB using colored paint and silk (plastic) or > metal screens, So the outline of the component was helping the operators to > stuff the board, and the RefDes was to make sure you were using the right > part, and also for trouble-shooting a failed test. > When the board is fully assembled, the outline is meaningless, only the > RefDes keep its value. > > And there is no difference in purpose between Through Hole and Surface > Mounted parts. > For polarized capacitors, I have seen a lot of different options, the most > efficient one being a circle or a square with a “+” sign to show the > polarity, The “+” sign or sometimes a dot being outside the shape. > What is important is that the marking eliminate ambiguity, but does not > jeopardize reliability. So it is VERY important that it does not touch or > cover a solder area. > > my $0.02, > > Jean-Paul > AC9GH > > > On Jun 8, 2014, at 11:14 AM, Carl Poirier <carl.poirie...@gmail.com> > wrote: > > > About these rules for the silkscreen, are they only for SMD? I am under > the impression it does not apply well to THT components, for example an > electrolytic capacitor where we often see a circle with one half full to > indicate polarity. This would be partly hidden once the board is assembled. > > > > > > On Thu, Jun 5, 2014 at 5:24 PM, Bernd Wiebus <bernd.wie...@gmx.de> > wrote: > > Hello Pawel. > > > > Am Montag, den 02.06.2014, 09:57 +0200 schrieb Paweł Dras: > > > > > With pads over the silk is the same situation, in many cases after > > > silk erasure by solder mask it don't looks good on final product. > > > > It is not only about "looking good". Silkscreen print over Pads is > > nasty, if someone forgets to distract the pads from the silkscreen. > > It may be expensiv, but shure will cost time at last..... > > > > If you place your silksceen across pads, and erase it over the pads, > > your silkscreen will be chopped. so better you chopp it by yourself and > > make it looking good. > > > > > > > Another problem is to wide placed silk. > > > > Think about, that you perhaps need place for rework tools. > > And wave soldering needs more space around the devices than reflow. > > > > Some years ago, KiCad insisted in thik lines, because you could not > > change the wide of silk screen lines. Of course, it was possible by > > editing the library file by hand. > > > > But this thick lines are sometimes needed, because a manufacturer who > > use a real silk-screen printing process and not a optical process, meeds > > the wide lines. > > > > So bee careful, if you use thin lines. Think about the spacing. > > > > > I have a question, can be ref and value placed as in my attachment or > > > should be above and below resistor? > > > > It is a bad idea, to place text under devices, because it cannot be read > > anymore, if the device is once mounted......so i put text to this > > positions, only if there is nowhere a better place for the text. > > > > Personally, i switch the value at layouts and silkscreens to invisible, > > and keep only reference as a designator. > > > > Having reference AND value at the layout costs place and is terrible to > > read. So better i use only the reference, and the BOM of course. ;O) > > > > For big boards with few devices, it migt be ok to have both, but for > > growing sisze, it will get diffcult to read. > > > > the exeption is, if you use the silk-screen not as an silk-screen at the > > board, but as an assembly layer. So you are not stuck to board > > dimensions, but can make DIN A2 prints for boards the size of a small > > stamp. ;O) > > > > With best regards: Bernd Wiebus alias dl1eic > > > > > > > > > > > > -- > > Mailing list: https://launchpad.net/~kicad-lib-committers > > Post to : kicad-lib-committers@lists.launchpad.net > > Unsubscribe : https://launchpad.net/~kicad-lib-committers > > More help : https://help.launchpad.net/ListHelp > > > > -- > > Mailing list: https://launchpad.net/~kicad-lib-committers > > Post to : kicad-lib-committers@lists.launchpad.net > > Unsubscribe : https://launchpad.net/~kicad-lib-committers > > More help : https://help.launchpad.net/ListHelp > >
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