Hi all,
Can anybody pls tell, What is the effect of Unbalanced Layer stack up ? or sometimes it is required to unbalance the Core or prepage thickness for some Desing requirements?
And what is the difference if We use Core in center or we use Prepage in center .because somedody told me that we shuld use like
Top Layer
CORE
Signal 1
Prepage
Signal 2
CORE
Bottom layer
it there any difference if we replace core and Prepage ?
This will help, https://pcbtalk.com/data/upload/Designing_Balanced_PCBs.pdf
I never use unbalanced lay-ups and never had, to much risk of bow and twist.
Foil build is more common these days, and stack up depends on signal speeds, impedance matching etc etc, if none of these factors are critical both methods will work. Talk to your supplier and pick the best cost/quality option for your design.
Marc
Hi All ,
Pls Help ,as i saw one Stack up ,of 1.5 GHz and the layer stack up is
Top Layer
CORE (Rogers) 422 uM
MId Layer 1
Prepage
MID layer2
CORE (FR4) 508 uM
BOttom layer
Here it is working Card and u will find Different Materail in Top and Bottom ,and Different Thickness .
PLS tell is it right ,unbalanced Layer stack up.