Single-sided and Double-sided PCB is a matter of routing and design convenience at the cost of a more complicated manufacturing process.
Single-sided PCB is the basic one，the spare parts are concentrated in one side, and the circuit are concentrated on the other.Because the wires only appear on the one side of themso we called Single-sided PCB. Because the single-sided PCB has many strict restrictions on the design circuit (because only one side, the wiring cannot cross and must move around the individual path), so it only used on earlier circuits.
Single-sided PCB diagram mainly used Network Printing(Screen Printing), that is,resist on copper surface, After etching, mark the welding resistance, and then finish the hole and the shape of the part by punching.
What is Double-sided PCB?Strictly speaking, the Double-sided board is one kind of the important PCB boards which is useful in PCB industry. They allow for the routing of traces around each other by jumping between a top and bottom layer by way of vias. Generally speaking, There are lines on both sides! The common PCBs can be seen such as, Printed circuit board,Flexible circuit board, Aluminum Based PCB and High frequency boards.
It need circuits on both sides. Via is the holes on boards, coated with metal and it can connect wires on both sides.Because the area of Double-sided PCB is twice as large as the Single-sided PCB,and because the wiring is interleaved, which is better suited for circuits that are more complex.
Someone may feel confused that if one Double-sided PCB, wires on both sides while Electronic parts only one side, is this a Double-sided board or a single onel? The answer is obvious. This kind of board is a Double-sided board, it's just install a component on the Double-sided board.