Circuit board PCB design and process

In PCB design, double or multi-panel is generally used, and the functional distinction of each layer is clear. There are two cases of package in a multi-layer structure. One is a pin package, that is, the via hole of the solder joint is through the entire circuit board; the other is an STM package, and the solder joint is limited to the surface layer; The span is the distance between the terminals after the component is formed.

1. Preparation before PCB design

Draw a schematic and then generate a netlist. Of course, if it is a very simple circuit diagram, you can directly design the PCB.

2. Enter the PCB design system

According to personal habits, the environmental parameters of the design system, such as the size and type of grid points, the size and type of the cursor, etc., can generally adopt the default values of the system.

3. Set the relevant parameters of the board to set the parameters such as the size of the board and the number of layers of the board.

4. Introduce the generated network table

When the network table is introduced, it is necessary to check and correct the errors in the circuit schematic design. It is especially important to note that in the schematic design of the circuit, the problem of part packaging is generally not involved, but when the PCB is designed, part packaging is indispensable.

5. Arrange the position of each part package

The system's automatic layout function can be utilized, but the automatic layout function is not perfect, and the position of each part package needs to be manually adjusted.

6. Conduct routing rules settings

Wiring rules include setting the safety distance, wire form, etc., which is a prerequisite for automatic routing.

7. Perform automatic routing

The automatic routing function of the Protel 98/Protel 99se/dxp/dxp2004 system is relatively complete, and the general circuit diagrams can be laid-through; however, some lines are not satisfactory and manual adjustment is required.

8. Save by printer output or hard copy

After completing the board layout, save the completed circuit diagram file and then use the various graphics output devices, such as the wiring diagram of the printer or plotter output board.