PCB Design - Common pitfalls to avoid

PCB short for printed circuit board has an electronic circuit design embedded with electronic components on a mechanical structure. It acts as a foundation for wiring and supporting the small components and surface mounting. PCB boards are the prerequisite of the electronic-based industries. While designing a PCB board, the designers keen to make some common mistakes that may result in a damaged or erroneous PCB circuit, which can’t be used for any devices. So, it is highly important to make the PCB design with utmost attention and care. To avoid committing the general mistakes, it is advisable to be familiar with the issues that can lead to the inoperable PCB circuit. Following is the list of some usual mistakes that every engineer commits during designing PCB. This is made available by a well known company called TronicsZone based on their expertise in this area.

• Selection of inappropriate designing tool:

Selection of the right designing tool is primarily one of the major fundamental steps for achieving accurate PCB design. Selecting an inefficient or faulty designing tool for PCB design will only give birth to problems like delayed in creating design and rise in manufacturing costs. Hence, it is advisable to choose the designing tool considering the requirements of PCB design. There are numerous easily operated EDA or electronic design automation software packages available for the designers from which they can choose the designing softwares accordingly. It is always better to acknowledge oneself with the features and analysis of designing tool to select the appropriate design tool for the PCB design.

• Inept layout techniques:

To create efficiently fast and compact devices, PCB designers are advised to design complicated layouts of electronic circuits for PCB. Since the requirements of minimal footprints are increasing with time, PCB designers need to use smaller components to fulfil the needs of the industry. By using smaller components, the footprint of the circuit is reduced, which means the electronic components are placed very close to each other in the circuit design. Due to this reason, it is important to go for competent designing techniques. If the designer chooses incompetent techniques for PCB design, then there is a possibility that the connections can go wrong or not connected as desired. Hence it is required to select an appropriate circuit board layout technique while working with high pin count and small pitch.

• Incorrect positioning of Decoupling Capacitors:

Decoupling capacitors are those electronic components that regulate a stable voltage in the circuitry and are situated on the electricity supply rails. These capacitors can work efficiently if they are kept as close as possible to the pin needing a stable voltage. If these capacitors are incorrectly placed far from the pin with stable voltage, these capacitors will not operate properly.

• Failing to Back-up the data:

PCB designers use disparate software and design plans are used to accomplish fruitful results in the designing process of PCB e.g. EDA software aids in creating complex layouts of PCB designs to the designers. Since the softwares are more versatile and fast enough, there is a high possibility that the data can be easily lost before the designer tries to save them. So, the designers or engineers should frequently save the data by creating savepoints to secure the data. By adopting this policy, the designer will be able to secure his/her data even if any storage points are corrupted.

• Inadequate power trace width:

The width required for power trace depends upon these two factors:

1. Weight of thickness of the copper foils.
2. External or internal layer.

The minimum allowable requirement for a power trace will not be adequate if more than 500mAh current is flowing in PCB traces. The thickness of PCB trace depends on the amount of copper being used in the layers. An external trace carries the higher current for similar width or thickness than the internal layer. When measuring the ability of a PCB trace to carry current, it is important to specify the permissible rise in temperature for that particular trace. To avoid erroneous PCB trace width, it is mandatory to follow the above-mentioned details.

• Placement Patterns Mistakes:

The tools of PCB design softwares contain all the libraries of the electronic components that are commonly used. PCB landing patterns and schematic symbols for each component are included in these libraries. However, the utilisation of the components which are not available in these libraries might cause some trouble to the designers. The landing patterns and schematic symbols of a PCB design need to be drawn manually which increases the probability of unavoidable mistakes when landing a component's pattern.

• Reducing Slithers:

When designing a PCB circuit, the circuit board are exposed to some undissolved pieces of copper, which may get stick to the board known as slithers. The availability of these slithers on the circuit board may lead to short circuits and various manufacturing failures. So, it is important for the PCB designers to always check that the minimum width of the copper is always above the requirement of the manufacturer. This process aids in reducing decomposition of slithers and producing functional circuit boards for the devices.

• Shortage of Design Reviews:

The process of reviewing of PCB design is one of the important procedures in designing circuit boards. Design reviews always aid the designers to avoid the usual design mistakes. This process involves reviewing the parameters of the circuit design, operability of the PCB along with checking the connection of each component of the circuits. Moreover, the opinions of other engineers and designers help to find the mistakes that earlier did not catch the designer's eyes when creating a PCB design.

Conclusion:

Designing an accurate and operable PCB circuit is a tedious job that needs to be done with sincerity and attention. If proper care and attention are not paid during the drafting the circuit plans and the PCB designing process, it may lead to a malfunction PCB design. The above-mentioned points are the common mistakes that need to be avoided when designing PCBs. If you follow these points, it will help you in accomplishing a fully-functional PCB in your first attempt. Failing to acknowledge the afore mentioned issues will create the possibility of designing inefficient prototypes, resulting in costlier expenses and delay in fulfilling the demands of the market on time.