In my former lives, last century, I always cross-hatched, especially on
inner layers. Never any problem with imbalance, better adhesion of
solder mask, less risk of delamination etc. I still applied thermal
breaks etc. The CAD package I used gave free choice of width/space
dimensions. Testing of characteristic impedance over cross hatching
revealed absolutely no difference or reflections (thickness of
dielectric in our case ~0.3 mm), provided the space between the hatches
was less than the dielectric thickness.
Another point I found is that a client had massive solid planes with 105
µm copper on inner layers for a power application (hairy at best!!!).
During pressing, he tended to have resin starvation, as it flowed to
fill where there was no plane. He changed to a low-flow resin and didn't
have enough in the non-plane areas. I advised cross-hatching with 5 mm
width/space: no further problem and he still had enough copper to pass
the curremt.
IMHO, it has everything going for it and nothing against it.
Brian
James Head wrote:
> I'll use hatched planes occasionally, to "even" etching across the board
> material, but only on mixed plane/signal layers. It depends upon the
> board, how much copper tracking and plane area is on the board and in
> what areas.
>
> James
>
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