While our previous posts explored the landscape of medical PCBs and the key qualities of medically applied PCBs, this post dives into hands-on lessons from real-world production and design experiences.
Printed Circuit Boards (PCBs) were originally developed as a simple solution to support and connect electronic components, eliminating the need for complex point-to-point wiring. The PCB is now a prominent part of our daily lives. But as technology advanced, that simplicity gave way to complexity. Today’s PCBs can involve multilayer stackups, multiple drill and press cycles, and require extensive certifications to meet application-specific demands. These complexities represent just a small slice of the broader PCB supply chain. Managing risk in a standard PCB supply chain is challenging enough – those challenges are amplified significantly when the application involves higher demands such as life-saving medical devices.
How are medical devices different?
Before diving into field lessons, it’s important to recognize what sets medical PCBs apart from standard commercial or industrial designs. While many PCBs are built to IPC-6012 or IPC-6013 standards and often fall under broader systems like ISO 9001 or ISO 14001, medical PCBs add another layer of complexity with ISO 13485. This standard serves as a globally recognized Quality Management System specifically tailored to medical devices, and it extends into the PCB supply chain. For the PCB supplier, this means stricter expectations around documentation, risk management, and traceability at every phase of the product’s lifecycle.
Full traceability over time
ISO 13485 goes beyond just verifying that a board meets electrical and mechanical requirements, it addresses how regulatory obligations are met, how records are retained, how risk is managed, and how subcontractors are qualified. For example, if a PCB is part of a life-sustaining or implantable device, full traceability of materials and processes may be required for decades. That level of control isn’t something every PCB supplier is set up to manage. It demands a robust quality system, trained personnel, and well-defined controls that hold up to external audit scrutiny. Suppliers that meet these criteria are not just vendors; they’re long-term partners in compliance.
Important to use the right partner
Adding to the challenge is the physical complexity of the medical PCBs themselves. Many designs are highly miniaturized, and some combine ultra high-density interconnect (UHDI) features with rigid-flex construction. Finding a PCB supplier is easy, but connecting with the right partner that can build under a certified ISO13485 system is not so simple. As the number of prepared suppliers shrinks, lead time, cost, and material availability can be affected. In many cases, sourcing the right supplier becomes just as critical as the design itself.
Tips to maximize the PCB design
Maximizing design in the PCB industry starts well before a single board is built. Early in my career, I worked as a solder mask technician and followed a handful of simple procedures. But when I moved into front-end engineering, things quickly became more complex. The supplier floor simplifies manufacturing as much as possible, but it’s not until you step back and look at the full data package; Gerber files, fabrication drawings, stackups, arrays, that you begin to see how crucial the design phase really is. I’ve learned that the more complete and accurate the procurement data package is, the fewer delays and surprises will occur during tooling.
Don´t underestimate the fabrication drawing
The fabrication drawing is one of the most important tools a design engineer can use to communicate requirements. Years ago, PCB manufacturing could get by with minimal or even missing fabrication notes. But in today’s landscape with multiple solder mask colors, surface finishes, and via protection options, those days are gone. Yet I still see quote requests without fab drawings. That might be acceptable for a simple commercial board, but IPC-6012EM and IPC-6013EM explicitly require a “computer readable” digital drawing for medical PCBs. Beyond compliance, this drawing accelerates quoting and tooling by giving the supplier exactly what they need to understand the design intent.
Keep the fabrication notes clear
One common problem I see is vague or contradictory fabrication notes. For example, a note like “Drill sizes are finished hole sizes” can create confusion, especially since plated holes are always over-drilled and then plated down. A more accurate note would be: “Hole sizes are finished sizes unless otherwise specified.” Redundancy in drawings is another risk. When a stackup drawing specifies one board thickness, but the fabrication notes say something different, the tooling process slows down adding to the list of engineering questions. Every contradiction in the documentation increases the risk of error or delay – especially during revision spins when not all documents are updated consistently.
Stackups and impedances
When I worked in the factory, part of my front end work was to design stackups and impedance traces. One day, after finishing a DFM analysis, I was talking on the phone to a PCB design engineer about the design. During the conversation, he mentioned impedance traces in the design. I was confused because none of the procurement documentation specified that. I then learned that he does not specify impedance traces and leaves it up to the factory to meet the exact stackup. In addition, he was confident that standard manufacturing will suffice to hit the impedance targets. I now realize this occurs often. The truth is it works, probably many times, but it is a practice I recommend against. When a PCB supplier tools the board impedance, traces get special treatment. The engineers find the specified impedance traces in the Gerber data and look at the return plane. After that he or she will build an in-house stackup based on the customer’s stackup and calculate the impedances. The in-house stackup will be very close to the provided one. It may not be exact due to the supplier using real time press data. Many times, the PCB supplier will have to slightly adjust the dielectrics in the stackup and/or adjust the impedance traces. This is the typical treatment front-end engineers give to controlled impedance traces. This ensures they will meet the targets on the final product.
Proper documentation is key
To maximize the design phase, it’s essential to provide a complete, clean, and unified set of documentation. If something isn’t needed, leave it out. If something must be specified, make sure it’s specified once; correctly. The goal is to eliminate assumptions at the supplier and minimize unnecessary back-and-forth during tooling. A streamlined design package leads to faster quotes, smoother production, and fewer surprises along the way.
Tips to maximize PCB supplier performance
Another way to reduce risk in the medical PCB supply chain is by maximizing supplier performance through strategic alignment and continuous collaboration. In the medical sector, where patient safety and regulatory compliance are non-negotiable, the performance of the PCB supplier must be consistent, documented, and verifiable. This requires more than just placing an order with a capable supplier. It demands a structured, proactive relationship that ensures the supplier is continuously operating at its best, especially when producing boards for life-critical applications.
Approve only for technologies they excel at
Maximizing supplier performance starts with knowing exactly what each facility can and cannot do. This means conducting detailed audits to assess the technologies the supplier can reliably and repeatedly produce. Medical PCB sourcing should be systematic: factories should be qualified not just for general capability, but for the specific builds they excel at. It’s common to think one “qualified” supplier can do it all; but experience shows that consistent success comes from matching the build to the supplier’s strengths. Ongoing, on-site follow-up ensures that what was true during the audit remains true throughout the production cycle.
Operational discipline and commitment to sustainability
Beyond capability matching, supplier performance also depends on operational discipline. Key indicators include whether the supplier has documented controls for handling non-conformances, trained personnel in quality-critical operations, and engineering support staff who can interface with medical OEMs when questions arise. A supplier’s commitment to sustainability and clean manufacturing processes should also be reviewed, especially as environmental regulations tighten across the industry.
For medical builds, the “build-to-print” requirement is critical, but it doesn’t stop there. Many customers specify a “copy exact” strategy, meaning the PCB must be built exactly the same way every time, with no substitutions or unapproved changes to materials, processes, or suppliers. This expectation must be hardwired into the supplier’s tooling and work instructions. Without this level of control, even a well-made PCB may not meet the requirements for consistency and traceability that medical device manufacturers demand.
Conclusions
In the Medical sector, reducing risk in the PCB supply chain requires a holistic approach that spans design optimization, supplier qualification, and strict adherence to regulatory standards. From the initial procurement package to final production, every detail must be controlled, verified, and repeatable. ISO 13485 compliance, robust design documentation, and supplier alignment are no longer optional, but essentials. As medical PCBs continue to increase in complexity and criticality, success depends on more than just building a functional board. It depends on building a process that ensures safety, consistency, and traceability from concept to completion. The lessons from the field are clear: the more you invest in design clarity and supplier performance, the more you reduce risk in PCB production.