Common Mistakes in PCB Design Beginners and Hobbyists Should Be Aware Of
Pulse
Octopart Staff
Dec 12, 2017

Written by Seeed Studio

Designing your first PCB for manufacture can be a daunting or exciting task. Newcomers either dive straight in or get worried sick that their creation will not come out exactly the way they want it. Regardless, it can be difficult for inexperienced users to find the right information relevant to them.

As a PCB prototyping service tailored to hobbyists, makers, and small-scale productions, Seeed Fusion sees a good deal of beginner mishaps that either ruin hours of design work or simply prevent us from manufacturing the boards. In this segment, we would like to share with you some common mistakes and provide some advice related to designing for manufacture that we encounter on a daily basis but are often not mentioned elsewhere.

Research the Fab House Rules and Specification
Probably more important than researching your chosen PCB fab house is researching the preferences and rules of the fab house in regards to your design. Everyone knows that you will need to provide Gerber files, but the exact format, required layers and precisely how you communicate your design to the manufacturer can differ drastically. For example, while one manufacturer may follow plated and non-plated holes according to the name of the layer where they are located, another may follow the actual design of the hole in the files. Similarly, how you layout your design can affect the price of the boards. For example, many manufacturers charge per design and have rules regarding how the designs are separated. Lack of research beforehand may result in nasty surprises later and may force you to desperately rethink your design or budget at the last minute. Be sure to understand and make use of any design tips and tricks early on to get the best value for your money.
Choosing Your Design Tool for Manufacture
Even before you start thinking about the layout of your design, you should do ample research in the available design tools according to your specific needs.  At the same time, you should also consider the fab houses to make it easier for them to assist you should you need it. For a hobbyist who may not be able to afford the more professional tools such as Altium Designer, the free options may be more suitable. However, we advise against picking an obscure or indie tool in favor of the more popular mainstream tools that may require a small fee or subscription. The reason for this is that there will be more documentation and support for the beginner using the mainstream tools, and should any issues come up at least the manufacturer engineers will be more able to assist you since they will more likely have experience using the tool.

Regarding exporting the fabrication outputs, this procedure can be very perplexing for the beginner. Each tool has its way of exporting these, and it can be very easy to get this wrong! But every tool has its characteristic problems that the engineers will be able to identify quickly. For the popular tools, manufacturers will often provide guides that will tell you how to export the files exactly how they want them and avoid common pitfalls. Some manufacturers will even offer to generate the files for you or offer files to help you in the design process. If you choose an obscure design program, then you are all on your own.

Keep it Simple
PCB capabilities and technologies are vast and ever pushing the limits. While it may be tempting to try to utilize advanced features such as blind and buried vias, fine pitch components or impedance control, these will increase the cost and complexity of your boards considerably and may not be necessary. If possible, try to design your boards to avoid having to use these features. Often, makers and beginners are not subjected to the spacing constraints of high-end consumer equipment, and a simple two-layered board within 100mm^2 is adequate for even the more complex designs. Once you become more experienced with PCB design, you may find the need for these features.
Double, Triple, Quadruple Check Your Final Design.  Then Check it Again
There is nothing more devastating than spending days on a design, waiting weeks for it to arrive only to find that the boards do not work due to an incorrectly routed trace or short. While it is blatantly obvious advice, we cannot stress it enough. You may be able to salvage the boards, but it may not be feasible if you intend on distributing them, for example. Fab houses will often check the Gerber files for common errors such as shorts and DRC violations and have tools to help, but we cannot tell if a trace has been routed to the wrong pin or if pads are missing. If something looks a little odd, we may catch it, but you shouldn’t rely on the manufacturer to cover error checking for you since it is not guaranteed and, as the designer, you should understand the design more than anyone else.

Please note that some fab houses do not check and report errors found in the files and produce the boards according to the files directly. Therefore, it is even more paramount that you check the final design carefully.

In designing PCBs for manufacture, hobbyists encounter, often for the first time, the need to consider manufacturing aspects of their work. In truth, PCB manufacture is a complex, technical field that is poorly documented, though it may seem simple from how manufacturers advertise their services. Though it may appear daunting, we hope that beginners will learn from any mistakes and continue to pursue their interests.

If you would like to know about advanced considerations in PCB design for manufacture or are just interested, please check out Seeed’s DFM publication here.

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