Common PCB Design Mistakes

Innovative design tools and manufacturing techniques have driven the cost of creating and producing printed circuit boards (PCBs) down considerably in the past few years. But what really adds to the cost of PCB production are errors in the actual design of boards from the beginning. There are a number of common mistakes in designing PCBs that not only newcomers and hobbyists need to be aware of, but experienced designers can learn from and avoid, as well.

Avoiding these common mistakes will result in reduced cost through avoiding rework and fabrication delays, while also producing a higher quality end product.

1. Not bringing the anticipated fabricator into the design early in the development stage. Most manufacturers have their own proprietary manufacturing processes that streamline production and maximize the efficiency of their particular equipment and workforce. If PCB design specifications are not aligned with their processes it could result in manufacturing delays, special setups that will increase costs, or even a board that they’re unable to produce. This can mean wasted time in finding another fabricator or a redesign of the board. Manufacturer’s input to the design may help design engineers create a more cost-effective PCB that is easier and faster to produce.
2. Get a second (or third) opinion. Designers are often focused on a specific purpose and result and working under a tight deadline for PCB production. This can lead to missed errors or design flaws that are simply overlooked in the effort to complete the design and develop a prototype. Having another technician or engineer review the design can be extremely beneficial in avoiding mistakes that may not surface until late in the process, resulting in higher cost to the project. As with many technical endeavors, the later in the cycle mistakes are discovered, the more expensive they become.
3. Layout – component placement – shrinking footprints for PCBs in today’s devices such as thinner televisions, smartphones, and weight-sensitive products require smaller and thinner PCBs. This challenges designers to layout components efficiently and more closely. Layout techniques utilized in the PCB design phase will become more and more critical to create reliability and manufacturability. Layout mistakes can turn into rework and failed prototypes.
4. Testing – thorough testing is essential to avoid issues once prototypes have been created. Not only must the initial functional requirements of the design be met, but any environmental circumstances that could potentially affect reliability or stability of the board should be vetted to ensure performance under a wide range of circumstances. PCBs that work as prototypes could otherwise fail when integrated into a final product.
5. Lack of applying tools – every designer should take full advantage of the design tools available. Some are structured for specific needs while others provide a broader range of flexibility for many types of PCBs. Sophisticated software aids in the design of PCBs including component placement, scanning designs for errors, and development of prototypes. Best of all, many such tools are extremely cost-effective or even free to use and web-enabled. Ignoring these high-quality and useful tools is certainly a critical mistake a PCB designer can make.
6. Not considering the manufacturing process. A complex and advanced design that works beautifully in theory is of little value if the PCB cannot be fabricated within budget, if at all. The importance of working closely with suppliers of the end product is a factor engineers need to keep in sight throughout the design process.

Avoiding Common PCB Design Mistakes

There are numerous methods available to avoid most of these common PCB design mistakes, from following best practices in methodology that include design reviews and collaboration with suppliers, to utilizing technology in design and prototyping.

Put design tools to work to minimize problems and provide specification files that are ready for fabrication. This contributes to project success with boards that are designed right the first time and produce the expected results. Providing all the necessary files to suppliers for fabrication ensures accurate information and a PCB that meets the designer’s requirements.

Utilize Design for Manufacturing (DFM) tools that analyze finished designs for manufacturability. Multiple questions and issues exchanged between designer and fabricator stretch the time to completion and add considerable cost to the final working product. FreeDFM is one such tool that will assist designers in avoiding critical mistakes.