07/29/2017 at 15:08 •
After receiving my new re-designed PCBs for #4chord MIDI - which is a real world example of putting this project here into reality (and pictures of that are now in the gallery), I thought I'll get familiar with the whole subject of solder paste stencils. This made me finally understand what the "Paste" layers are for, and I created the Gerber files for them to have a look at it.
Yep, the footprint in my Github repository includes the solder paste layer for both the connector pads and the solder pads on the back side. This is fine - or simply doesn't matter - for PCB manufacturing. However, for stencils, this may or may not be a good thing.
Personally, after experimenting some amount with OSH Park's ENIG finished PCBs, I don't have any need for solder on the connector pads, and haven't decided yet how to deal with the pads on the back side, but will potentially stick to hand-solder them. In that case, I wouldn't want to have the pads exposed in the stencil.
This might be different for you. Or I might change my mind in the future. And sure, you can always edit the pads while designing the PCB and adjust the solder paste layer individually, but figured I add some shortcut.
So long story short, I extended the Nokia 5110 LCD footprint library to contain a total of four footprints:
- Nokia_5110-3310_LCD without any solder paste layers
- Nokia_5110-3310_LCD-B.Paste with solder paste layer on the back side soldering pads
- Nokia_5110-3310_LCD-F.Paste with solder paste layers on the front side connector pads
- Nokia_5110-3310_LCD-F.Paste-B.Paste with solder paste layers for both, i.e. the original footprint
Note, once again, if you are only interested to use the footprint for PCB design, it won't matter which footprint you use. This is only relevant for creating PCB stencils.