Design in different stages need to set up a different point in the layout phase can be used to carry out large grid layout of the device;

For IC, non-positioning connectors and other large devices, you can use 50 ~ 100mil grid point precision layout, and for resistive capacitors and inductors and other passive small devices, can be used 25mil grid layout. The accuracy of the grid is conducive to the alignment of the device and the appearance of the beautiful.

PCB layout rules:

1, under normal circumstances, all components should be arranged on the same side of the circuit board, only the top components too close, in order to some limited and small heat of the device, such as chip resistors, chip capacitors, paste Chip IC, etc. on the lower level.

2, in ensuring the electrical performance of the premise, the components should be placed on the grid and parallel or vertical arrangement, in order to neat, beautiful, in general, does not allow the components overlap; components to be compact, the components in the entire layout should Uniform distribution, density consistent.

3, the different components on the circuit board adjacent to the minimum spacing between the drawings should be more than 1MM.

4, from the edge of the circuit board is generally not less than 2MM. The best shape of the circuit board is rectangular, aspect ratio of 3: 2 or 4: 3. circuit board ruler greater than 200MM by 150MM, should consider the circuit board can withstand Mechanical strength.

In the PCB layout design to analyze the circuit board unit, according to the function of the layout design, the circuit of all components layout, to meet the following principles:

1, according to the circuit of the process of arranging the location of the various functional circuit unit, so that the layout of the signal flow, and make the signal as much as possible to maintain a consistent direction.

2, to each functional unit of the core components as the center, around him to the layout. Components should be uniform, overall, compact arrangement on the PCB, to minimize and shorten the lead between the components and connections.