Most common 4 layer board has 1oz outer layers and 0.5oz inner layers?

[cupoftea]

Hi,
If you want a cheap 4 layer PCB, and really you want 1oz on all 4 layers.........is it true though, that the far cheaper and more common option is 1oz outer, 0.5oz inner?........and the 1oz inner needs the 0.5oz inner to be plated up to 1oz, and as such involves an extra production step which may result in mistakes in the board due to eg alignment problems?

 

[FvM]

Wrong assumption, 1 oz on inner layers uses substrates with 1 oz metallization, high power PCB use e.g. 2 oz. The main reason to go for 0.5 oz is finer trace width and spacing.

 

[KlausST]

Hi,

but outer layers may be initially 0.5oz and then galvanically added another 0.5oz to get 1oz.
.. to connect the different layers using vias.

Klaus