COMPONENT DESIGN


Engineering electronics for real-world stresses


OEMs can ensure longevity through material and mechanical testing W


hen a device slips from your hand, its internal components feel the impact too. Mechanical shock is a leading cause of failure in electronic assemblies, with studies indicating that vibration and shock contribute to 20 per cent of mechanical failures in airborne electronics. Here, Stephanie Williams, senior product specialist at materials testing instrument manufacturer Instron explores how material-informed component design and validation go hand-in-hand to ensure reliable electronics.


As electronics become smaller and more intricate, every material choice in a component carries risk under bending, heat, humidity or vibration. Testing transforms these risks into measurable margins. A resin with high stiffness can maintain alignment during soldering but may fracture if exposed to repeated bending. Composites with greater elasticity tolerate movement yet risk gradual deformation under load. Thermal behaviours often drive these trade- offs. Polymers begin to soften well below the operating limits of metals, while differing expansion rates between materials can place strain on joints or embedded traces. Electrical factors add another layer of complexity. The dielectric strength and surface resistivity of a material influence circuit stability and long-term insulation performance. Each of these properties must be verified against the real mechanical and


thermal stresses a device will encounter during its service life.


When materials are matched to those conditions early in the design process, components last longer and behave more predictably across production runs.


Mechanical and environmental stresses


Once materials are chosen, the next challenge lies in understanding how they respond to mechanical stress. Components may flex during assembly, absorb vibration throughout their service life or experience impact from accidental drops. Even minor deflection can create strain at solder joints or weaken thin dielectric layers. Repeated loading, such as the constant vibration inside an automotive control unit, accelerates fatigue in rigid substrates.


Heat and humidity compound these effects, altering how materials deform or how adhesives and coatings behave over time. Edge impacts are particularly revealing, as they show how stress waves travel across complex geometries.


In medical devices or safety-critical electronics, such degradation can have severe consequences, making it essential to quantify these effects through controlled testing before designs reach production. You cannot rely on theory alone, however. You need empirical data to validate what you


design.


A drop tower system like the Instron 9400 series can deliver a controlled impact that creates a shock pulse to help quantify failure thresholds. A pendulum with or without full instrumentation can be used to provide insight into how an edge impact or strike can propagate stress across geometries. HDT testing confirms how material stiffness softens under heat. Universal testing machines, including electromechanical frames, allow you to drive controlled displacement or force at precise rates; useful when simulation insertion or bending loads until fracture occurs.


By cycling through the ‘design, test, refine’ philosophy, engineers can adjust wall thicknesses, reinforce weak zones or swap in alternate polymers or metals. The repeatability and precision of these systems can give engineers confidence that the improvements seen during testing are real, rather than artefacts of noise or setup variation. Material-aware component design cuts out many failure pathways at the start, boosting reliability and consistency over time. Merging foresight in design with rigorous, repeatable mechanical testing gives you confidence that electronics will endure real use. Engineers and specification leads can gain a clearer picture of the trade-offs and make smarter choices when design and testing evolve together.


28 OCTOBER 2025 | ELECTRONICS FOR ENGINEERS


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