On Sun, Dec 17, 2017 at 11:20 PM, Luke Kenneth Casson Leighton lkcl@lkcl.net wrote:
On Mon, Dec 18, 2017 at 6:03 AM, Richard Wilbur richard.wilbur@gmail.com wrote:
So it might be easier to just put a ground keepout on layer 2 under the ESD component on layer 1 and a corresponding ground fill on layer 3. Likewise a ground keepout on layer 5 under the ESD component(s) on layer 6 and a corresponding ground fill on layer 4.
yehyeh. ah.... do you mean the *whole* component? conflicts with putting keepout(s) under individual pads...
I was recommending just under the ESD pads specifically for the high-frequency differential signals.
conflicts with words above about "GND keepout under ESD components"...
Sorry for the misunderstanding. I wasn't very clear about delineating the difference between two options for dealing with the ESD component pads. 1. Ground keepout under whole ESD component(s) on adjacent reference ground plane (layer 2 for ESD on layer 1, layer 5 for ESD on layer 6), ground fill on deeper layer (layer 3 for ESD on layer 1, layer 4 for ESD on layer 6). Ground fills connected as always using vias (some probably already adjacent). 2. Ground keepouts under just high-frequency signal pads of ESD components on adjacent reference ground plane (layer 2 for ESD on layer 1, layer 5 for ESD on layer 6).
Clear as mud?