The printed circuit board, or PCB, is responsible for connecting all the components with each other in your electronic assembly. Making just one tiny error in the design could lead to complete failure. PCB layout design requires ardent precision and great technological skills.
Manufacturing techniques and innovative design tools have enabled Printed Circuit Boards (PCB) manufacturers to bring down the cost of PCBs in the past years. However, the cost of production can increase due to errors in the PCB design. That means it is imperative for PCB designers to avoid such fabrication errors, while designing PCBs for an electronic assembly.
Incorrect landing patterns
All PCB design software tools include libraries of commonly used electronic components. These libraries include both the schematic symbol, as well as the PCB landing pattern. All is good as long as you stick with using the components in these libraries.
Problems begin when you use components, not in the included libraries. This means the engineer has to manually draw the schematic symbol and the PCB landing pattern.
It’s very easy to make mistakes when drawing a landing pattern. All it needs is an error of half a millimeter or less while measuring the pad to pad spacing and it will become unfit for soldering during the manufacturing process because the pins won’t align.
Incorrect Antenna Layout
If the product has any wireless functionality the PCB layout of the antenna is critical.
The transmission line connecting the transceiver and the antenna should have 50-ohm impedance in general. Setting the microstrip’s width based on the dielectric specifications for the PCB does this.
It also must have an LC pi-network or any other matching circuit is to be placed between the antenna and the transceiver for fine-tuning the impedance of the antenna. This allows fine-tuning of the antenna impedance for optimum matching and maximum power transfer.
Incorrect Placement of Decoupling Capacitors
Decoupling capacitors are the equipment that helps maintain a stable voltage. These capacitors are present on the power supply rail. To be effective, these capacitors should be placed very close to the pin that requires stable voltage. If you do not make sure that the power line from the source is routed to the decoupling capacitor first and then to the pin which requires the stabilization, the process fails. Also, in order to maximize the capacitors, they should be placed as close to the component pins as possible.
It is also critical to place the output capacitor for the power supply regulator as close as possible to the output pin of the regulator.
This is necessary for optimizing stability (all regulators use a feedback loop that can oscillate if not properly stabilized). It also improves transient response.
Mistakes in PCB layout can lead to huge losses. Therefore, controlled PCB design is an important check to prevent any low-quality products from reaching the market. This is why is it so important to obtain DFM analysis or partner with an electronic manufacturer service with engineering in-house with can look over your design for you.
You should also consider getting a design review of your electronic assembly from an independent engineer before you produce any prototypes. An independent design review could help you avoid a prototype that doesn’t work. That, of course, could delay manufacturing and cause your budget to skyrocket.
It’s All About Communication
When you think you’ve got the best design, look over it again for errors. Make sure you know how your final design with function and share that with your electronic manufacturing service. The more communication you have with your electronic manufacturing service the better end result of your prototype.