This stack-up provides an adjacent ground and power airplane at L10 and L11, which makes the L12 (resulting from higher isolation) ideal to route analogue signals. For the reason that introduction on the PCB, electroplated nickel/gold has existed. This surface area finish applies a coating of nickel to the area https://beckettrwyzb.ageeksblog.com/30204308/copper-based-pcb-for-led-an-overview