What should be the thickness of dielectric to make 2mm gap?

[neena]

layout cross section

hi

i am working with a four layer board
and the gap between the inner layer should be 2mm gap
how much did i have to give the thickness of dielectric
Is there any standard values to be assign


thank u
regards.......

 

[Rame]

Re: layout cross section

Hi Neena,

If you are talking about controlled impedance board,then you need to tell the pcb fabricators regarding the Board Impedance(like 75 100ohms etc).Rest fabricator will take care.Hope this will help you.And you can ask any fabricators for information.Hitech in bangalore may provide details your looking for...

Regards

Rame

 

[binu G]

Re: layout cross section

normally the impedence requirement will define the spacing of the layers.
if impedence is not an issue then u can select ur own option.
i have attached one option here, also it depend on the fabricator too.

 

[neena]

Re: layout cross section

hi

if impedance is not an issue
and i want the board thickness of 2mm
with copper foil thickness of 2oz
how to choose FR4 values

if for controlled impedance
how and what values to be used


regards
........

 

[binu G]

Re: layout cross section

here i have attached the layerstackup.
confirm with ur vendor will he able to select the dielectric with given thickness.

Binu G