Component selection and placement decisions go hand in hand and when one is misjudged, the entire design can suffer. With today’s increasingly dense and complex PCB layouts, even experienced engineers can overlook critical design details that affect functionality, manufacturability, or mechanical fit. These issues often surface late in the development cycle, leading to delays, rework, or costly design revisions.

To help avoid those setbacks, we’ve outlined seven commonly missed elements in component selection and placement. Whether you’re designing your first board or refining your process, these reminders can help ensure your layout is robust, efficient, and production-ready.

1. Not making sure components fit inside the packaging after the PCB is assembled
   Becoming too fixated on selecting working components but ignoring how they fit inside the packaging will result in a nonfunctioning or compromised design. When this happens, the chassis must be redesigned altogether, which could compromise the original vision and require starting the component selection process over from scratch. This headache can be avoided altogether if the components’ height clearance is observed from the start. Since height clearance restrictions vary by component, it is best to draw a basic board shape outline during the early stages of design, taking care to place some of the larger components where they may go on the board. This allows for quick visualization of the components’ position relative to their heights.
2. Neglecting to consider the pros and cons of SMT and FTH components for each circumstance
   Surface-mount-technology (SMT) components are, on average, less expensive and more readily available than fixed-through-hole (FTH) components, but this does automatically qualify them as a better choice. Part density, power dissipation, size of the PCB and how the soldering pads will be accessed for debugging are all factors to consider early in the design stage. SMT components may be preferred for smaller PCBs, but soldering them by hand is infinitely more difficult without a reflow oven. In contrast, through-hole components can be adequately soldered by hand if the PCB is large enough.
3. Not having enough bypass capacitors and ground planes
   Designers should ensure that a sufficient amount of bypass capacitors and ground planes are used in the PCB. Failing to place bypass capacitors across from the power and ground pins on the appropriate IC pin results in a circuit with nonoptimized electromagnetic compliance and compromised performance. Similarly, the correct number of decoupling capacitors must be placed near the supply to a ground plane, or some other ground location, when using integrated circuits.
4. Not checking for virtual part footprints
   Rather than solely reflecting the number of components and raw materials needed to manufacture an end product, the bill of materials (BOM ) can also be used to reveal the number of virtual parts, which do have footprints associated with them and are not transferred to the layout. Virtual parts are used for simulation and need to be replaced with parts that have actual footprints, so do not forget to include them in the BOM.
5. Not thoroughly reviewing the BOM
   Forgetting to thoroughly review the BOM report may leave part, vendor, and manufacturer information incomplete and disorganized, thus creating an inaccurate representation of the total cost. The BOM will not fulfill its purpose without complete information.
6. Not using reference designators
   Failing to closely number reference designators will overly complicate the reviewing process of the BOM and prevent accurate sorting.
7. Forgetting to verify spare gates
   In the haste to assemble a prototype, it can be easy to forget to verify that all spare gates’ inputs are connected to a signal. If spare gates are not connected to a signal, there is nothing in place to prevent the inputs from floating, thereby running the risk of compromising the entire system and preventing it from properly functioning. Debugging is a headache that can otherwise be avoided with thorough inspection. Therefore, it’s important to review all forgotten or spare gates to ensure that the inputs are connected.

Conclusion: Design Success Starts with the Right Details

Every PCB project hinges on careful planning and attention to detail—and component selection and placement are among the most critical early decisions. Overlooking even a single factor, like packaging constraints or missing bypass capacitors, can cause issues that ripple through prototyping, manufacturing, and even field performance.

By proactively checking these commonly missed elements, engineers can streamline their design process, reduce production delays, and deliver boards that meet both functional and mechanical requirements. Investing time upfront pays dividends later—and helps ensure your next PCB build moves from concept to completion without unnecessary setbacks.

Originally published July 10, 2025 by Judy Warner at The Electronics Eecosystem

When it comes to practical, actionable DFM (Design for Manufacturability), I have one go-to person: Gerry Partida, VP of Technology at Summit Interconnect.

I’ve known Gerry for over a decade and have always appreciated how he brings clarity to the often-murky space between PCB layout and fabrication. With more than 25 years of experience preparing fabrication files, Gerry has become a trusted authority on all things DFM.

Early in my career, I spent 16 years selling PCB fabrication services. I worked closely with designers, engineering teams, and manufacturing managers–constantly bridging the gap between design engineers and front-end engineering teams at board shops. Over time, it became crystal clear that a successful PCB design didn’t just rely on the designer, but equally on the skill, DFM expertise, and communication of the fabricator’s front-end engineer. That perspective sharpened my ability to recognize real DFM talent—and Gerry stood out from the start. He’s been my go-to expert ever since.

So today, I’d like to (re)introduce you to Gerry and pass along the top DFM lessons I’ve learned from his decades of experience. I hope these insights help your next design handoff go more smoothly—and help you avoid costly delays or respins.

Top Seven DFM Tips I’ve Learned from Gerry

Here’s a concise list of DFM best practices Gerry consistently emphasizes:

1. “Control what you can control.”
This is Gerry’s cornerstone principle. Don’t leave critical manufacturing decisions—like stackup, padstack specs, or impedance targets—to the fabricator. The clearer and more intentional you are, the better your outcomes.

2. Don’t assume your fabricator knows your intent.
Designers often assume their fab house will “get what I mean.” They won’t. Be explicit—especially around impedance control, materials, and via structures. When possible, include supporting data.

3. Communicate early and often.
Working on a high-speed or complex board? Reach out to your fabricator before finalizing your design. A 15-minute call could save you days—or even weeks—of production delays.

4. Avoid Gerber-only packages.
Gerbers alone are risky. Provide a full data package with intelligent formats like ODB++ or IPC-2581, plus fab drawings, netlists, and material specs to avoid misinterpretation.

5. Don’t recycle old fab notes.
Copying fab notes from previous designs without reviewing them is a common mistake. Always update notes to reflect the current design and manufacturing requirements.

6. Be realistic with annular ring and drill tolerances.
Just because it passes in CAD doesn’t mean it will work in the shop. Account for drill wander and registration tolerances when defining via and pad sizes.

7. Know your fabricator’s capabilities.
Not all shops are built for HDI, flex, or RF boards. Match your design to your fabricator’s strengths—and if you’re unsure, ask early.

Why This Matters

As Gerry often says: “A design isn’t successful until it’s built, tested, and shipped—without drama.” And that success starts long before your board hits the fab floor.

Too often, designs are delayed or rejected because critical data was missing, assumptions were made, or documentation was unclear. The fix? Start thinking like a manufacturing partner, not just a designer.

If you’re a layout engineer, hardware designer, or someone who regularly interfaces with your CM or fabricator, you owe it to yourself to learn from experts like Gerry Partida. His practical wisdom has saved more than a few projects and reputations.