FEDEVEL
Platform forum

mulfycrowh , 02-24-2019, 02:23 AM

Hi everyone !

The purpose is a 4 layers PCB.
My PCB manufacturer suggests different buildups for the same thickness of PCB.
What are the options to select one among the other ones ?
The other question is: when I select one buildup, am I going to be able to ask for the same buildup with another manufacturer ?
As far I understand impedances depend on layers' thickness …
So ...

Thank.

Paul van Avesaath , 02-24-2019, 03:08 PM

manufacturers are depended on the stock fr4 they receive. if they have to buy to your specific stackup the cost will be high.. if you can go to their preffered stacks then alwasy do that..indeed if you have impedances then you can change your tracks with the info you get from manufacturing or let them do the impedance matching for you..

you can always switch from manufacturer and hope that the material you chose was pretty normal.. but again.. layerstacks may vary, thats why having them do the final check and changes to your gerbers with regards to the impedance is recommended.

i dont know what you had to begin with.. so it might be that you have an extreme case.. but usually the fr4 stuff is for most manufacurers the same.

robertferanec , 02-26-2019, 01:18 AM

If you only care about power distribution and you do not design your stackup for impedance controlled or sensitive tracks (high speed, RF, ...), only what may be important for you is thickness of the copper layers (e.g. 1oz, 2oz, ..). You do not need to worry much about the specific stackup.