[SOLVED] need some help on pcb layer information

[kwagjj]

I'm not sure if this is the right forum but it looked like the one most related to my issue

I'm asking about the 'hardware' of the pcb actually and I thought that most of you might have some experience with this as well as the software side of pcb design.

I asked the vendor about the 4 layer pcb layer info so that I could simulate it.

I received a figure like this:




I figured out what the 'oz' and 'C/F' 'C/L' 'P/P' means.

But there are some things that are unclear to me

1. could there be a special reason for the prepreg(P/P) to be expressed in two layers?(as in 0.18T/0.11T adding up to 0.29mm in thickness). Is it just a common process to use two layers for pregreg?

2. At the bottom of this figure(not shown in the image) the vendor stated that the material of the pcb is Fr-4. Then does this mean that the Core laminate(C/L) and the pregre(P/P) both are FR-4??

 

[rube]

1.P/P is a semi-finished product, for good production and layers symmetric;
2.The same FR-4, may be FR-4 dielectric constant have some different depending on your board thickness and impedance control.

 

[sapphire_2010]

1. To meet standard board thickness two or more pcs of prepreg is used. Its common practice. Make sure you request any stackup always mention if there is any impedance matching requirements. Impedance depends on P/P & Core thickness & PCB material as well.
2. Usually same material is used for P/P & Core .......& it is recommended.

 

[kwagjj]

thanks! this was the answer that I needed!