12-13-2015, 05:20 AM
(This post was last modified: 12-13-2015, 06:22 AM by dsm.
Edit Reason: improve clarity
)
13Dec2015
In addition to the board dimensions (see http://wiki.pine64.org/images/7/74/Pine6...ension.JPG),
it would be useful to know something more about the mounting hole specifications. For example,
• MH-center-to-MH-center dimension (horizontal and vertical)
• board-edge-to-MH-center dimension (horizontal and vertical)
• mounting hole diameter (what size bolts)
• mounting hole keepout diameter (what size nuts and standoffs)
• mounting hole solder mask diameter
It looks like the mounting holes are plated-through-holes. There is an argument to be made for non-PTH mounting holes so that (1) threaded mounting hardware doesn't tear the PTH leaving little metal bits to short out the board and (2) relying on mounting PTH for grounding often leads to flaky behavior if the mounting hardware tears up the PTH. My preference would be for a non-PTH mounting hole, keepout applied to all layers (including internal ground plane), solder mask up to the mounting hole, and marking the keepout boundary on the silkscreen layer.
dsm
In addition to the board dimensions (see http://wiki.pine64.org/images/7/74/Pine6...ension.JPG),
it would be useful to know something more about the mounting hole specifications. For example,
• MH-center-to-MH-center dimension (horizontal and vertical)
• board-edge-to-MH-center dimension (horizontal and vertical)
• mounting hole diameter (what size bolts)
• mounting hole keepout diameter (what size nuts and standoffs)
• mounting hole solder mask diameter
It looks like the mounting holes are plated-through-holes. There is an argument to be made for non-PTH mounting holes so that (1) threaded mounting hardware doesn't tear the PTH leaving little metal bits to short out the board and (2) relying on mounting PTH for grounding often leads to flaky behavior if the mounting hardware tears up the PTH. My preference would be for a non-PTH mounting hole, keepout applied to all layers (including internal ground plane), solder mask up to the mounting hole, and marking the keepout boundary on the silkscreen layer.
dsm
