Dielectric height to 4layer pcb

Hi,

I am wondering how is the height of the dielectric btw 1st and 2nd or 3rd and 4th layer in a 1.6mm PCB Thickness, in a non impedance control procedure.

Is there a dielectric range of this specification?

Another description for the above is: What is the stack up for your 4 layers pcb with 1.6mm thickness?



At the following picture, the question is focus to the two grey regions (upper & down). Is there a specification of height range about this?



Hellooo,



These might have what you are looking for:

<LINK_TEXT text=“http://support.seeedstudio.com/knowledg … per-layers”>http://support.seeedstudio.com/knowledgebase/articles/671596-what-is-the-thickness-of-the-inner-copper-layers</LINK_TEXT>

<LINK_TEXT text=“http://support.seeedstudio.com/knowledg … fusion-pcb”>http://support.seeedstudio.com/knowledgebase/articles/1086106-what-is-the-thickness-of-fusion-pcb</LINK_TEXT>

Many thanks for the replying.



Yes, these are what I have searched! Thanks again.



But, If this is 0.2mm (Prepreg or FR4 is the term or your links) and not varies, then we can have an impedance control at the Fusion PCB procedure to 4layer pcb!

But, at the Fusion PCB there is a choice for “Impedance Control” with extra payment.

What is more when this enabled?

The 4 layer stack-up shown in the links is for our standard non-impedance controlled fabrication process. Of course, if impedance control is selected, the engineers will modify the stack-up and traces accordingly to meet specified requirements.

Many thanks for reply to my answers!

No problem!