CMOS camera control circuit
A 6 layer PCB board is in general a 4 layer PCB Board with 2 extra signal layers added between the planes. The 6-layer PCB classic stackup includes 4 routing layers (2 outer layers + 2 internal layers) and 2 internal planes (one for ground and the other for power). This enhances the EMI dramatically by offering 2 buried layers for high-speed signals and 2 surface layers for routing low speed signals. The signal layers should be closed to the adjacent planes.
6 layer PCB
Storm Circuit Technology Ltd , https://www.stormpcb.com