A display is one of the few electronic subsystems where PCB design decisions become visible to the end user. A few milliohms of resistance, a slight impedance discontinuity, or a few degrees of temperature difference may never matter elsewhere in the product. In an LED display, however, those same design decisions can become a visible defect. Behold the power of the human eye.
Over the years, I've reviewed hundreds of PCB layouts spanning everything from industrial controls and aerospace electronics to medical devices and high-speed computing systems. Every design presents its own unique challenges, but display electronics have always stood apart. They demand a different way of thinking because success is measured by what the customer sees, not solely by electrical performance.
I've often said that experienced PCB designers struggle with LED displays, not because they lack technical knowledge, but because they apply the same design mindset that has served them well elsewhere. Display electronics require a subtle but important shift in perspective. You're no longer designing only for electrical performance; you are designing for human perception.
Here are three lessons I believe all new and experienced PCB designers should keep in mind when designing an LED display for the first time.
1. Every Electrical Decision Becomes a Visual Decision
One of the first things I look at during a display board design review isn't the LED array itself. I look at the power distribution network. I know that’s surprising, because most engineers naturally focus on signal routing, LED drivers, or interface circuitry. Those are certainly important, but I've learned that many display problems begin with how power is delivered across the board.
Unlike many electronic systems, where voltage variations remain invisible to the user, LED displays convert electrical inconsistencies directly into optical inconsistencies. A slight voltage drop across a copper plane may seem insignificant during simulation, yet it can create subtle brightness differences that the human eye detects immediately. The irony is that the design may satisfy every electrical requirement.
To continue reading this article, which appeared in the July 2026 I-Connect007 Magazine, click here.