On Fri, Jun 16, 2017 at 7:51 AM, mike.valk@gmail.com mike.valk@gmail.com wrote:
2017-06-16 8:19 GMT+02:00 Luke Kenneth Casson Leighton lkcl@lkcl.net:
there's not really any other options: you can see how little clearance there is to the edge of the board: it's flat-out impossible to bring tracks in either in between those two sets, or round the back... and you don't want to anyway: they're differential pairs (up to 1ghz clock rate) because this is HDMI.
Hmm. Then how are other users of this connector doing it? This seems like a generic problem. The solder technique is generic afaikt.
- Either they are using smaller width tracks and are passing between the
left hand pads.
like i said: there's not enough room to get that many tracks between the pads, and it would violate differential-pair rules to do so.
- They have via's right to the pads. But that's very close to the edge.
exactly.
The options I see... . find other schematics using this connector.
none.
. Use smaller width tracks.
can't.
. Cut the pads tight a little shorter and place the via's to the right creating a bottleneck but stil far enough from the edge
possible.
. The above but to the left, via's in the middle.
possible but risky.