Printed circuit boards or PCBs are popular because of the relatively low cost to manufacture them and the speed with which most designs can be assembled. However, it is quite easy to make mistakes during the design phase that derail a product or create problems for your customer. Here are four common printed circuit board design mistakes to avoid at all costs.
Who Cares about the Rest of the Hardware?
A common printed circuit board design mistake is forgetting that the PCB has to fit into the rest of the design. Whether ignoring how the PCB will be assembled into the protecting housing, whether it will interfere with other components assembled around it, or neglecting to consider the PCB connects to the data and power sources are, unfortunately, common problems.
This issue is compounded when they neglect to consider how wiring will fit in and around the components when the PCBs are stacked together with a motherboard inside of a protective case.
In Theory, It Will Work
Too many companies pay someone to design the circuit board, only to find out the design is not buildable by their contract manufacturer or shop floor. You can avoid this mistake by sending the preliminary component placements to the assembler for their input; sooner is better than later because it is far costlier to change the design later in the design process.
Not So Hot Designs
When a circuit board overheats, its performance degrades, and the entire unit is at risk of shutting down. Yet thermal studies of designs are secondary compared to the analysis of electromagnetic interference and power supply. The problem still comes up when system cooling is designed as part of the assembly due to the assumption that there’s a fan, so the unit is good.
They don’t make certain that the cooling effect reaches the hottest part of the board or that the final assembled product cuts short that air flow, so the customer risks a unit shutting down from overheating if not failing due to parts shorting, burning, and melting.
No Margin for Error
One variation of this mistake is not leaving any room on the printed circuit board design for extra components that may be necessary. You now have a design rendered obsolete because there’s no room for the extra two capacitors or resistors. Altium Design Software has features that allow you to make these last-minute design changes while maintaining the parts lists and manufacturing instructions up to date, which is key when avoiding this mistake.
Another version of this mistake is designing something that only functions when conditions are precisely met. The real world isn’t going to guarantee high-quality power supplies and software glitches.
The third form of this error is designing on the assumption that every component will be exactly the size you expect, so it falls apart if the parts are plus or minus one percent in terms of size. You need to design circuit boards with a degree of robustness.
These and other mistakes can be easily avoided with a well-coordinated design team.