ethanjli
commented
3 years ago Since we'll need to regenerate the footprints at https://github.com/prakashlab/octopi-driver-board/tree/develop/Parts/Connectors/Backbone_Connector_Hirose.pretty , while we're at it we might as well also fix the reference designators on the Fab layers.
After updating the footprints we should fix the 3D models for the footprints, in each PCB layout file.
PCBWay has reported that they cannot fab ODSv1.0.0-PP-T41v0.1.1 and ODSv1.0.0-BP-Jmpv0.2.0 in red soldermask because the spacing between the pads of the Hirose FunctionMax FX20 connectors is 0.2 mm rather than the minimum of 0.22 mm needed for red soldermask; green soldermask allows for lower spacing between pads. I'm not sure why this is a problem now since it wasn't a problem in the ODSv1.0.0-PP-T41v0.1.0 fab order from PCBWay.
Currently the width of each pad is 0.3 mm, following the FX20 datasheet's t=0.12 specification. I now suspect that t may represent the thickness of the stencil, so that a thinner stencil requires a wider pad for the amount of solder needed. If we reduce the width of each pad to 0.25 mm, then we'll have 0.25 mm between each pad (allowing us to use red soldermask), and we may be able to reduce solder-bridging when we apply solderpaste ourselves using 0.12 mm stencils.