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Beyond the Board: Why More Defense Primes Are Moving Toward Rigid-flex for Lighter, More Reliable Systems

Over the past decade, the conversation around PCB innovation in aerospace and defense has often centered on high-density interconnects, advanced materials, and tighter design-to-fabrication collaboration. But the move toward rigid-flex is a quieter shift that has been gaining momentum, and it’s changing how primes and system integrators approach the physical architecture of mission-critical electronics.

In an industry where every gram, cubic inch, and potential point of failure matters, rigid-flex isn’t just a design evolution, it’s a system-level strategy. Increasingly, major defense primes are rethinking traditional rigid board assemblies interconnected by harnesses and connectors instead of rigid-flex architectures that combine structural rigidity with the flexibility to bend, fold, and integrate seamlessly within constrained enclosures.

From Rigid Assemblies to Integrated Reliability
Legacy defense platforms often relied on multiple rigid boards connected through cabling. This approach was easier to design around but introduced insertion loss, mechanical stress points, connector failure risks, and additional weight. In today’s aerospace environments, those design tradeoffs are no longer acceptable.

Rigid-flex designs eliminate interconnects that can loosen under vibration or thermal cycling. They also reduce overall system weight and allow for more compact packaging, promoting critical advantages for aircraft, satellites, and high-performance sensor systems where reliability and signal integrity must be preserved under extreme conditions.

By embedding flex circuitry between rigid sections, designers can route high-speed signals across multiple planes with tighter impedance control, fewer discontinuities, and shorter overall electrical paths. The result is improved performance and reduced susceptibility to EMI, while also simplifying final system assembly.

Following established design standards, such as IPC-2223, adds a layer of predictability and confidence to this process. The guideline outlines best practices for bend radius, conductor routing, stack-up balance, and coverlay design. This allows design engineers to anticipate mechanical stress and optimize flex performance before fabrication begins. By incorporating IPC-2223 during the design phase, teams can reduce rework, minimize prototype iterations, and achieve consistent mechanical and electrical outcomes across builds.

Driving Factors: Weight, Reliability, and Manufacturability
Weight savings in aerospace programs have a compounding effect. For satellites and UAVs, a lighter electronics suite can translate directly into greater payload capacity and endurance. For manned platforms, it can mean extended range and improved energy efficiency. Rigid-flex boards enable these benefits by consolidating components into a single structure that’s both electrically robust and mechanically optimized.

At the same time, reliability expectations are rising. The elimination of connectors and cables doesn’t just reduce points of failure; it removes entire maintenance categories. When combined with modern materials capable of withstanding wide temperature swings and repeated flex cycles, rigid-flex becomes an inherently more durable solution for dynamic environments, such as avionics bays, gimbal-mounted sensors, or guided munitions.

IPC-2223 also reinforces these reliability gains by prescribing proven strategies for dynamic flexing, strain relief, and copper balancing. These principles ensure that designs remain robust under repeated motion or vibration, critical for aerospace applications where field failures are not an option.

Another emerging driver is manufacturability at scale. Historically, rigid-flex was viewed as a specialty technology with long lead times and higher costs. However, as domestic fabricators invest in multilayer flex capabilities, laser drilling, and advanced lamination controls, those barriers are quickly eroding. The technology is maturing into a scalable, repeatable option suitable for both prototypes and production runs.

A Shift in Design Thinking
Rigid-flex adoption isn’t just about substituting materials; it’s about rethinking how systems are architected. Engineers are now designing around the flex zones themselves, optimizing component placement to exploit the three-dimensional freedom rigid-flex offers. This approach allows for creative packaging in areas previously constrained by form factors or access.

What’s particularly interesting is that many primes are building rigid-flex expertise directly into their new platform development processes. Rather than treating PCB design as a downstream task, they’re involving PCB layout and fabrication partners earlier in the design cycle. Integrating IPC-2223 guidance into this collaboration provides both design and manufacturing teams with a shared, standards-based vocabulary, helping them align on bend tolerances, material selections, and mechanical constraints early in the process. This collaboration helps balance electrical performance, manufacturability, and mechanical reliability before the first prototype even leaves CAD.

Looking Ahead
As the aerospace and defense sectors continue pushing toward lighter, smarter, and more integrated systems, rigid-flex will play a foundational role in bridging the gap between mechanical design and electrical performance. It’s not just about fitting more into less space; it’s about ensuring every interconnect and every trace is optimized for mission assurance.

The industry’s gradual but steady migration toward rigid-flex represents not only an engineering preference, but also a mindset shift. Reliability, weight reduction, and design efficiency are no longer competing priorities; they’re converging under a unified architecture that’s both structurally sound and electrically superior.

By anchoring design efforts in IPC-2223’s proven framework, aerospace teams gain both the performance advantages of rigid-flex and the process predictability required for mission-critical manufacturing.

Rigid-flex is becoming the new baseline for aerospace electronics that can’t afford to fail.

Jesse Vaughan is a senior account manager at Summit Interconnect.