Computer Aided Design – or CAD – is known as a process by which computer software is used to draw, design and develop a concept or product. Visual representation of an object can be created with the help of CAD programs.
This technology is incredibly useful to a number of industries – design and manufacturing of printed circuit boards being one of them.
PCBs, and How They Are Designed Using CAD Technology
When it comes to developing or creating a PCB, manufacturers such as Super PCB have numerous types of CAD software to choose from. Every CAD software basically does the same thing, i.e. designs the visual representation of a PCB. But as every program works slightly differently, it’s up to the designer to choose the one that works the best.
Following are the stages of PCB design that are carried out at Super PCB;
Schematic Capture
The first part of this design process begins with the CAD technician mapping all the connections and the component positioning that will be placed on the PCB. In PCB jargon, this is known as schematic capture and it’s a blueprint for the circuit’s design.
The schematic capture basically determines the components which will be used in the PCB and how they’ll be joined together. CAD technicians or designers can either use schematic design that already exists (and fits requirements for the project), or create an entirely new one. To make sure how well the schematic is going to operate on an actual circuit; the designer runs simulation tests which reduce faults in the design of a PCB before its production.
Turning a Schematic Capture into a Circuit
It’s only after a schematic has been tested and approved can the second stage of PCB design be reached, i.e. the design is now transferred into an actual CAD visual representation (or drawing) of the circuit board.
This is the stage where dimensions of the PCB are determined as well as the placement of copper trace connections and different components.
The grid isn’t considered important when designing the schematic but plays an important part when it comes to editing the actual circuit board. At Super PCB, design and production of PCBS isn’t delayed as all designers are well trained and certified when it comes to designing the CAD of a circuit board.
As requirements of each printed circuit board are different, designers often leave room concerning the physicality, formation and placement of components which makes the production easier to complete, and with less errors.
In addition, after placing the components the designer provides complete information on the circuit board, including drilling information, footprint for the board pads, the use of each component etc.
Routing
This is the last stage where the designer routes the copper connections in between the components. Again, this is done with the help of CAD software that routes connections with the help of information collected with the schematic capture. Although manual routing is usually preferred, most CAD software will have a ‘route’ tool that helps too.
When routing the copper connections, designers must make sure to avoid crossing of traces. The small drill holes (called vias) that are present on the PCB are used to transfer traces from one side of the circuit board to another.
It’s only when routing is completed that designers run the CAD software and check for errors in the PCB design. The PCB design is deemed ready to be made into a new circuit board once all errors are corrected.
This process ensures that there are no errors and delays at the time of the manufacturing of printed circuit board. Of course, the experience and expertise in CAD software matter too. So, how will you know that a PCB fab house is really the best at what they do? Look at their facilities and the standard of quality control followed.