Voltage rating for internal PCB layer

[gmarocco]

I am designing a 4 layers PCB. Some parts of the PCB sholud carry a 26V voltage.
I would like to know if there are issues with this stack-up

1) Top copper: +26V plane
2) Internal layer 1: GND plane
3) Internal layer 2: +26V plane
4) Bottom copper: GND plane

I plan to use the following pcb thickness
- 70 micron for TOP and Bottom layer
- 35 micron for internal layers

Thanks in advance

 

[boot13hunter]

I am designing a 4 layers PCB. Some parts of the PCB sholud carry a 26V voltage.
I would like to know if there are issues with this stack-up

1) Top copper: +26V plane
2) Internal layer 1: GND plane
3) Internal layer 2: +26V plane
4) Bottom copper: GND plane

with regards to your stacking well....it depends. I would personally prefer the ground to be on the outside layer sandwiching the two active voltages....for safety reasons. other wise you have certain requirements.

I plan to use the following pcb thickness
- 70 micron for TOP and Bottom layer
- 35 micron for internal layers

are these number copper weights? because this would be to thin for pregs and cores, otherwise this is flex PCB. i assume this is a rigid type. imho you should be more concern on the current rating of your application since your running below 50V.

 

[Mattylad]

At 26v there are no safety issues that dictate any special layer stack, its essentially low voltage.

Are you not going to put components on the top? if so then that would be a signal layer, ditto the bottom as you will need to connect them up.

This is a very common 4 layer stackup.
Layer1) signal (ground pour in spaces)
Layer2) gnd
Layer3) pwr
Layer4) signal (ground pour in spaces)

 

[FvM]

The only PCB parameter that might be already critical in the low voltage range is horizontal copper-to-copper and particularly drill-to-drill and drill-to-copper spacing.