PCB - PCA10040's Stack-up question

[MANGO]

Hi, I use the PCA10040 v1.1.

This is an example of a PCB stack-up.

My questions are,

0. In the case of PCA10040, which is 4 layered, what are the values of height in each layer?

1. I'm creating a custom PCB using the nRF52832-QFAA.

However, due to cost, I'm going to make 2 layered, 1.6mm thick, FR-4 PCB.

The coplanar transmission line won't change even though I choose 2 layered PCB.

However, the height parameter of the stack-up seems to change.

If I create 2 layered PCB, what should be the height value to create a proper PCB?

-Best Regards

[bjorn-spockeli]

I only know the stackup of the nRF51 DK, but I think the stack up will be fairly similar since the design of the nRF5x DKs are close to identical.

The coplanar transmission line on a 2-layer 1.6mm thick, FR-4 PCB should be designed as shown below

[MANGO]

Hi, Bjørn. Yes, your assumption, set the thickness to 1.6mm, is correct.

Can you explain more about the

If this is just the substrate, i.e. the material inbetween
the copper layers on the top and bottom,
then you will have to subtract the thickness
of those layers form (from typo) 1.6mm.

I couldn't understand what you've meant.

Lastly, about the picture of AppCAD that shows the parameters of the coplanar transmission,

is the parameter L (length) is really 1000 mils (25.4 mm)?

That looks quite long compared to the real PCA10040.

-Best Regards