Question Wii Motherboard Stackup

[the_swan]

Hi there!

I'm new here so sorry if this is common knowledge but im struggling to find informaiton on it.

I am aware that the 4 layer wii motherboard is doccumetned here https://bitbuilt.net/forums/index.php?threads/wii-rvk-01-compendium-released.93/ but unless I am missing something this only details 3 of the 4 layer stackup.

Top and bottom being signal layers, and a 3rd layer being for various voltages. What is the 4th layer? Is it a large ground plane or something more complex?

 

[YveltalGriffin]

Yep, the other internal layer is entirely GND! You can see a glimpse of it in this partial scan I took.

The stackup from top to bottom is:

Top signal
GND
Voltage
Bottom signal