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]

Wow. Thanks for the detailed picture. Unfortunately, I don't know how to read Chinese.

What do the Chinese letters mean in English?

[bjorn-spockeli]

I do not know how to read chinese either, but the thickness is written in mm. If you need the thickness of the substrate then the its 0.0180mm*2 - 1.6mm.

[MANGO]

I see. Then, in the family section, what's the "IT158"?

The PCB manufacturer that I'm working with doesn't recognize the "IT158".

More importantly, due to cost, I'm going to make 2 layered, 1.6mm thick, FR-4 PCB. Then the thickness of L3 and L4 will be eliminated. Then how much thickness should I set when creating a 2 layered PCB?

[bjorn-spockeli]

I also do not know what IT158 refers to, I am assuming that its some kind of substrate. We do not produce the DKs ourselves, so this is sorted by the third-party manufacturer we use. If you're making a 2 layer 1.6mm thick FR-4 PCB then I would assume that you set the thickness to 1.6mm. 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 1.6mm.