How to Design a Circuit Board

It is exciting to learn how to design your circuit board, especially as newbies. We have summarized the whole process in 7 steps, which can help you have a rough concept about how to design a circuit board.

1. Pre-Design

Pre-design includes the preparation of component libraries and schematics. Before proceeding with the PCB design, you need to prepare the schematic SCH component library and the PCB component package.

It will be better that engineers design the library with standard size. In principle, the establishment of the PCB component package library comes first, and then schematic SCH component library comes second.

PCB component package library has strict requirement since it directly affects the PCB installation; It will better if you can use the components existed library rather to draw your own library. Like in Seeed Fusion, they offer OPL list and eagle library and Kicad library for the list, which makes the process easier.

Schematic SCH component library requirements are relatively loose, but pay attention to the definition of pin properties and PCB components package library correspondence.

If you have done the pre-design, and you don’t want to continue the next 6 steps, you can just upload the SCH in Fusion layout service page, instant calculation about how much it will cost for the design (design ready to be manufactured)

2. PCB Structural Design

According to the board size and the mechanical positioning, draw PCB frame in the PCB design environment and place the required connectors, buttons / switches, screw holes, assembly holes,etc according to the positioning requirements.
Fully consider and determine the wiring area and non-wiring area (such as the scope of the screw hole around the non-wiring area).

3. PCB Layout Design

Layout design is placing components in accordance with the design requirements in the PCB board frame. Create a network table (Design → Create Netlist) in the schematic tool, and then import the network table (Design → Import Netlist) into the PCB software. After that, the network table will exist in the software background, it can callout all the components and the pin between the line suggestions that can be connected through the placement operation, then we can have the layout design based on the components.

PCB layout design is the first important process in the PCB design process, the more complex the PCB board, the better layout required since it will directly affect the degree of difficulty to achieve the later wiring.
Layout design relies on the circuit board designer’s foundation and rich design experience, which means the requirement for the circuit board designers are strict. The experience of the primary circuit board designer is suitable for small module layout design or less difficult PCB layout design.

4. PCB Wiring Design

PCB layout design( wiring design) has the largest workload in the PCB design process, it directly affect the performance of the PCB board.

In the PCB design process, wiring generally have three realms: The first is the cloth pass, which is the circuit board design basic;

Followed by the performance of electrical performance, which is a measurement of a standard PCB board. After the line wiring, adjust the wiring, so that it can have the best electrical performance;

The last one is neat and beautiful. Chaotic wiring will bring inconvenience to the post improvement and test or maintenance, even the electrical performance is acceptable.

5. Improve the layout and silk-screen

“There is always better PCB design”, “PCB design is a defective art”, which is mainly because the PCB design needs to satisfy the requirement of the hardware design, however, there may be different conflicts between specific requirements.
For example: a PCB design project needs to be designed into a 6-layer board, but for considerations of production cost, the requirements must be designed into the 4-layer board, then only we have to sacrifice the signal shield formation, resulting increasing of the signal crosstalk between the layers and the decreasing of signal quality.
The general design experience is that optimizing the routing time is twice the time of the initial cabling. When the PCB layout optimization is completed, we need to have the post-processing. The primary treatment is the silk screen logo of the board, the design of the bottom of the silk screen characters need to do mirror processing, so as not to be confused with the top screen printing.

6. Network DRC inspection and structural inspection

Schematic diagram and structural elements map is the most basic design requirements, network DRC inspection and structural inspection is to confirm whether the PCB design meets the requirement of input of the schematic netlist and structural elements.

7. PCB Manufacture

Then congratulations on the design, you can just generate the Gerber file and upload in Fusion, choose the parameters to calculate the price instantly and place orders.

About Author


May 2017