4 Layer SMPS PCB....1 ounce copper on all layers?

[Faringdon]

Hi,
In days gone by, it was known that a 4 layer PCB with "1 ounce copper", would have 1 ounce copper on top and bottom layers....but the inner layers would be half ounce.
Just been quoting on China PCB places, and  it seems possible to have 1 ounce (or even 2 ounce), on all layers, and it doesnt mean big price increase.

So has the old "less copper weight on inner layers" thing  now  dead?

[Doctorandus_P]

I'm not sure if it ever existed.
If you look at: https://www.eurocircuits.com/pcb-assembly-standard-pool/ for example, they ave both 18um and 35um for inner layers in their default pools.

There are also a lot of high-current PCB's being made, such as for example motor drivers for electric vehicles, and these fall outside of the the defaults.

A bit more "normal" are PCB's for PC motherboards, and one Mobo manufacturer advertized with 70um for internal layers. The bigger PC processros can slurp up more then 100A, and that is quite a lot for a PCB to handle, and many of such PCB's are being made, and also have been made for lots of years.