What are the rules for PCB optical board wiring layout

The wiring layout of Pcb board is one of the most important factor for operation well or not. Pcb wiring is to lay printing wires according to the electrical schematic diagram and the conductor meter， as well as the required conductor width and spacing. Generally should follow below rules when layout wire:

1.On the premise of satisfying the usage requirement ,the order of choosing wiring mode is single→layer one→layer multi-layer, it means if wiring can be simplify do not make it complicate.

2.The signal on the same layer of the Pcb board change direction with oblique or smooth transition, and larger curvature radius is better , which avoids electric field concentration, signal reflection and additional impedance.

3.The wires between two soldering pads should be designed as short as possible that the sensitive  and small signals covey preferentially in order to reduce the delay and interference of small signal. Ground wire shielding should be placed beside the input wire of analog circuit, and the same layer wires should be evenly distributed. The conductive area of each wire should be relatively balanced to prevent the board from warping.

4.Digital circuits should be separated from analog circuits for wire layout to avoid interference mutually.

5.The circuit elements on the Pcba board should be grounded and connected to the power supply as short and close as possible,  so that reduce the internal resistance of the PCB board.

6.The length of I/O wires of high-speed circuit, differential amplifier and balanced amplifier should be same to avoid unnecessary delay or shift.

7.The wires of each layer on the multi-layer board should be perpendicular to each other in order to reduce coupling and avoid line-up or balance between upper and lower layers.

8.The thin wire should be not shorter than 0.5mm when it’s used for thermal isolation, and the thin wire width should not be less than 0.13mm,when the soldring pad is connected with the large and small conductive area.

9.The conductor which is most closest to the edge of PCB, should be over 5 mm from the edge of PCB, and the grounding wire can be close to the edge of PCB when it is needed.The distance between the wire and the edge of the board is at least deeper than the depth of the guide groove if the PCB is inserted into the guide during processing .