China Topscom Provide high difficulty density & printed circuit boards PCB design & layout, mass manufacturing & fabrication,pcba boards assembly,turnkey full systems integration electronic contract manufacturing services.

Layer 1, layer 2 is PCB,4 layer, layer 6, layer 8, layer 10,all of them are PCB boards,Which one do you do?
 
1KHz signals can walk on PCB, and 1M, 1G, 1G, and 10G signals can also be used on PCB. Which pcb can you draw?
 
1mA current can take the wire, 1nAMagne,1pAMagne,if 10fA u can handle it?
What about the 10A Magi 100A going up?
 
FR4 can be used to make PCB, Rogers, Panasonic,all of them have the PCB plates. Which one can you use for your application?
 
A little further, the board on the Flip-chip package is also a kind of PCB.
 
Finally, what kind of company and place do you do the job?
 
All these will affect your income level. PCB design is just a general name. Although the threshold is low, the way inside is not that simple.