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5 Common PCB Design Mistakes for Beginners
48 0 Sep 26.2025, 11:44:53

Stepping into the world of PCB design can be both exciting and challenging. It’s easy for beginners to fall into common traps that can turn a great idea into a frustrating prototype. This article will discuss five of the most frequent errors and how to easily avoid them.


1. Traces That Are Too Thin


A trace that is too narrow to carry its intended current can act like a fuse, heating up and even burning out. This is especially true for power lines. A good rule of thumb is to use an online trace width calculator. While a width of 10 mil (0.254 mm) is a safe starting point for basic signal lines, power and ground traces should be wider—at least 20 mil or more, depending on the current requirements.


2. Pads That Are Too Small


Making pads as small as possible to fit more components seems efficient, but it makes soldering a nightmare. Small pads risk "tombstoning," where one side of a surface-mount component lifts off the pad during reflow soldering. The solution is simple: stick to the standard footprints recommended in component datasheets, which are designed for manufacturability and reliability. For through-hole components, ensure the pad diameter is at least twice the hole diameter.



3. Forgetting Fiducial Marks


Fiducial marks act as a GPS for pick-and-place machines. These small, circular copper pads help automated machines precisely locate components. Without them, machines cannot orient themselves accurately, leading to alignment errors and placement failures. A modern standard is to place at least three fiducials on the board's outer edges in a non-linear pattern. This simple addition can prevent significant headaches during assembly.


4. Silkscreen Over Solder Pads


Silkscreen is intended for labeling, not for covering copper. Placing silkscreen directly over a solder pad prevents solder from forming a proper connection. This can lead to weak joints or even solder bridges, causing short circuits. Always keep silkscreen legends and outlines away from pads. A good rule is to maintain a small clearance of at least 4-6 mil (0.1-0.15 mm) between the silkscreen and any exposed copper.


5. Ignoring Component Spacing


Cramming components too close together may seem efficient, but it's a recipe for disaster. Insufficient spacing makes soldering, inspection, and rework nearly impossible. It also increases the risk of short circuits and thermal issues. Ensure there is enough room between components for proper airflow and to prevent neighboring parts from interfering with each other. A good rule of thumb is to give components, especially larger ones, at least 25 mil (0.635 mm) of clearance.


As a leading manufacturer, we at PCBgogo have helped countless designers bring their ideas to life. We've seen firsthand how a bit of knowledge about these common errors can make all the difference. Our goal is not just to manufacture your PCBs, but to ensure they are high-quality and reliable from the very first run. We offer comprehensive design rule checks and have a team of experts ready to catch these kinds of issues before they become a problem. We are committed to making the PCB design and fabrication process as smooth as possible for you.


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