In Reply to: Determining number of layers posted by Sara on 05/06/03 at 4:12 AM:
1)The number of layers is decided by the complexity of the design and the number of ground and powers in your circuit.
2) Usually the standard thickness depends on number of layers and your impedance requirements which inturn depends on the materials used for your pcb build and hence affects the pcb thickness.
3) usually for 2-6 layers the thickness is around 1.6mm and beyond this you can go in for 2.4mm thickness.
4) For huge analog boards which house relays, transformers, bulk components etc i.e the power boards have a thickness of 3.2mm.
5) You can get in touch with any pcb manufacturer who will help you out with your problem.
6) The inner layer seperation depends on the configuration ( symmetrical, asymmetrical stripline , embedded stripline etc etc) of your board. This seperation is decided by your design's impedance requirements.