"NeonJohn" == NeonJohn <jgd@...> writes:
On 11/3/22 16:36, russ95462 wrote:
Hi,
? ? I need a ground strap so I can connect the signal and power planes
at a point of my choosing. In the past it was possible with a bit of
messing about to create a component that did this, however I have just
had a board come back from manufacture and this time it has failed
because the latest kicad 6.0 will not allow GND and GNDA to be connected
even with a frigged component, see below.. Can someone please tell me
how to do this in Kicad, its a real nuisance not being able to do this
easily as its a feature all other CAD systems have.
This is an absolutely vital feature for what I'm now doing. I design
induction heater boards for my friend's company (fluxeon.com). On one
end of the board is the 3.3 volt processor and analog electronics
necessary to protect the SiC FETs on a cycle by cycle basis. On the
other end is a 10kW Royer-type power oscillator. I must tie GND and
PGND (power ground) together at one point.
4 layer board. The outside lower layer is PGND and the inner ground
layer is GND. In Eagle where I'm coming from, to tie the two together,
I simply lay down 10 vias in two rows of 5 as close together as my board
house can handle. On the bottom layer, the solder mask is manually
opened up in the software so that paste is applied across all 10 holes.
When reflowed, a continuous solder blob covers all 10 holes and fills
them with solder. There is no power flowing through this interconnect
but it has to be low impedance so the ground voltage will be the same on
both sides so, for example, the source current shunt low side will be at
the differential amp's ground. I use a differential op-amp for sensing
and for sensing the peak voltage across the FET but keeping the two
grounds at the same potential makes things more noise-resistant.
Isn't this what a Net-Tie is used for in KiCad?
My Rome, GA box builder is competitive with the chicoms until I add many
thru-hole devices to the board. A jumper would add cost to the board.
I run 50 boards as the pilot run and if everything works correctly, they
do a production run of 500.
I've been doing electronic design for decades and was an early
evangelist for open source. One guiding principle was and should be now
is that FOSS software is better than the nearest commercial equivalent.
Being able to connect two planes together directly in the software is vital.
I love this product and send money when I can so I'm an absolute
supporter of this project. Let's keep it the best out there.
