Estimated reading time: 4 minutes

Elementary Mr. Watson: Retro Routers vs. Modern Boards—The Silent Struggle on Your Screen

There's a story about a young woman preparing a holiday ham. Before putting it in the pan, she cuts off the ends. When asked why, she shrugs and says, "That's how my mom always did it." She asks her mother, who gives the same answer. Eventually, the question reaches Grandma, who laughs and says, "Oh, I only cut the ends off because my pan was too small." 

This story is a powerful analogy for how many PCB designers approach routing today. They follow outdated workflows, habits, or tool constraints simply because "that's how it's always been done." Manual routing, skipped automation, and many design cycles are leftovers from a time of limited tools and workarounds. However, today, we have bigger pans.

The role of the PCB designer has never been more complex or critical. As electronics continue to shrink in size and grow in functionality, the expectations placed on PCB designers expand: tighter timelines, more layers, higher speeds, and broader knowledge across disciplines. What was once mostly a layout-focused task has evolved into a multi-dimensional engineering challenge that blends electrical, mechanical, thermal, and manufacturing considerations. Gone are the days when routing a few nets and fitting parts on a two-layer board was enough. Today's boards must manage high-speed differential pairs, controlled impedance traces, dense BGA fan-outs, and power integrity—all while fitting into a compact package. Designers must understand signal integrity, RF constraints, stackup engineering, and the implications of firmware.

Complicating matters, design cycles are increasingly shorter. Companies ask that teams go from concept to production in weeks, not months. They expect designers to collaborate across global teams, manage library quality, and stay up-to-date with the changing availability of components. PCB design is no longer just about placing components and routing traces; it’s systems engineering, signal integrity, mechanical integration, and manufacturing science rolled into one. The learning curve is steep, the margin for error slim, and the demand for excellence high.

For decades, PCB designers only had manual routing available, which they regarded as a rite of passage—a symbol of craftsmanship, control, and deep understanding. Designers who routed every trace by hand took pride in their layouts, often viewing autorouting as a shortcut for those who lacked skill or patience. Manual routing became a badge of honor—proof that a designer had the experience, discipline, and precision to handle every detail personally.

For a long time, this pride was well-deserved. Autorouters often produced inefficient, messy, or non-functional results. They couldn't respect the designer's intent and lacked the intelligence to make nuanced trade-offs. However, the landscape has changed.

In many corners of the PCB design community, manual routing is the gold standard; the hallmark of a "true" designer. There is a mindset that if you don't route every trace by hand, you're somehow not doing "real" PCB design. That mindset is holding the field back.

The goal of PCB design is to deliver functional, manufacturable, and high-performance boards efficiently and reliably. If automation, assisted routing, or AI-enhanced design workflows help achieve that, then they are not cheats. They are advancements.

This doesn't mean manual routing has no place. Understanding manual routing is critical to mastering the logic of PCB design. However, insisting on doing everything by hand in a high-speed, high-density production environment is akin to insisting on drafting with a T-square and a slide rule in the age of computer-aided design (CAD). It proves stubbornness, not superiority.

So, how do we route our 21st-century PCB designs with our 20th-century tools? By balancing precision with productivity, control with speed, and traditional skills with modern tools. Manual routing is a tool in the toolbox, not the whole workshop. Furthermore, the evolution of PCB design tools has sparked a quiet divide in the engineering world. On one side are designers who swear by the old ways—routing every trace by hand, double-checking every corner, relying on experience and instinct. On the other hand, are those who embrace advanced EDA features: constraint-driven design, push-and-shove routing, real-time DRC, and AI-enhanced suggestions. However, the actual power lies in the balance between the two.

Manual routing is foundational. It teaches attention to detail, control, and a deep understanding of current flow, return paths, and signal integrity. It forces a designer to think through the consequences of every trace. These skills develop strong designers and must be retained. However, modern tools offer what human hands and eyes cannot: speed, scalability, and repetition. They can optimize large BGA breakouts in minutes, keep nets matched within microns, and prevent violations in real-time. Used properly, they allow designers to focus on engineering intent rather than pixel-by-pixel detail.

The key is finding the balance—learning when to guide a trace by hand and when to let the tool do the work. It's about setting up solid constraints, understanding the goals of the layout, and using automation to handle tedious and repetitive tasks so that human creativity and judgment can focus on the truly complex.

Balancing manual craftsmanship with modern automation isn't a compromise; it's a design philosophy. The best designers know how to route a delicate RF line by hand and how to use intelligent tools to manage a complex DDR interface in a tight timeline.

PCB design in the 21st century is about leveraging every advantage while staying grounded in the fundamentals. So, the next time you're halfway through a layout and tempted to route everything manually or ignore tool-assisted features, ask yourself: Am I cutting off the end of the ham?

John Watson is a professor at Palomar College, San Marcos, California.