pcb design problem in layer

[avi11111]

can any one tell me that , what is the difference between internal layer and external layer in pcb design.

 

[betwixt]

Internal = sandwiched between the top and bottom surfaces (usually a multi-layer board)
External = on the top or bottom surfaces, in other words visible to the eye.

Internal layers can not have components on them and must be connected to each other or the surface layers through vias.

Brian.

 

[marce]

https://bayareacircuits.com/manufacturing-of-double-sided-and-multi-layer-printed-circuit-boards/

 

[sorvilloschnepf]

there is more copper weight on external when compared to inner.
i have seen a board has 2ounce of copper on external layers and 1 ounce on inner layers.
Heavy copper will disipate heat better and carry more current.

 

[FvM]

there is more copper weight on external when compared to inner.

Not generally. It's a non-standard option used for some power boards. You can have higher copper weight on inner layers as well.

 

[NIKHILRAJ]

there is more copper weight on external when compared to inner.
i have seen a board has 2ounce of copper on external layers and 1 ounce on inner layers.
Heavy copper will disipate heat better and carry more current.

the opposite thing is also possible for some fabricators ... 2 oz internal layer , while external layer is with 1 oz

 

[marce]

there is more copper weight on external when compared to inner.
i have seen a board has 2ounce of copper on external layers and 1 ounce on inner layers.
Heavy copper will disipate heat better and carry more current.

Not a true statement, copper on inner layers can be heavier than the outer layer... You can have what you want within reason as long as the stack-up is BALANCED around the centre point, often do a mix of various copper weights.