Layout and design of PCBs have a large impact on the way a circuit will work, meaning that an effectively designed printed circuit board will perform much more reliably and within specification. There are several steps and processes required in the design of circuit boards.
Here, we will outline the process of designing printed circuit boards so you may have a better understanding of what is involved.
For commercial development purposes, there is electronic layout software available, such as computer-aided design (CAD) packages which companies such as Altium are likely to use. This type of software is often necessary due to the complexity of the printed circuit board being designed.
Being able to run simulations within a software environment is becoming increasingly important as the speed of boards increases and radio frequencies being used become higher.
The first stage in the development of a PCB design is to capture the schematic for the circuit. This may be achieved in a variety of ways. Circuits can use a schematic capture tool. This can be part of the PCB design software or it may be an external package.
When the schematic capture is finished, the electronic design of the circuit is contained within the file and it is then converted to what is known as a “netlist”. The netlist is the interconnectivity information and it is the circuit nodes and the component pins.
PCB design showing components and tracks
Before the design and layout of the PCB, it is required to get a rough idea of where on the board components are going to be located and if there will be enough space on the PCB to fit all of the required circuitry. This step will help decide the number of layers will be needed in the construction of the board as well as if there will be enough space.
When an estimate has been reached a more detailed layout can be made for the final design of the PCB. This can take into account things like the proximity of devices that may need to communicate with one another.
With the basic placement completed the next step in the design is to route the connections between all components. PCB software routes the connections according to the schematic. Often one layer will be used as a ground plane and another may be used as a power plane – this will reduce the level of any noise.
This routing process can use a significant amount of computing power. This is especially true for larger printed circuit board designs. This is because larger designs can involve thousands of different components. Where the routing can be particularly difficult because of the sheer number of components, the process can take a significant amount of time.
Of course, this is just a brief outline, the entire process can be very involved but hopefully, you have a better understanding.