PSI - Issue 79

Giulia Morettini et al. / Procedia Structural Integrity 79 (2026) 440–448

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same time, increased the sensitivity of PCBs to mechanical and thermal stresses (IPC Association (2018)). Vibrations, shocks can trigger fatigue phenomena in solder joints or component leads, reducing the service life of the assembly and compromising the reliability of the system. The design of a PCBA is a complex and interdisciplinary process that involves both electronic and mechanical engineering competencies (Steinberg (2000)). In industrial practice, however, structural analyses are often carried out only during the final validation stages, when the board layout has already been defined and is difficult to modify). This limits the possibility of intervening on critical areas, highlighting the need for a co-design approach that integrates structural and vibrational evaluations from the earliest design phases (Perkins and Sitaraman (2004)). The literature presents several models for predicting the fatigue life of electronic components. Among the most well-known, Steinberg (1971) proposed an empirical approach based on allowable PCB displacements, which is still widely used for its simplicity, despite being strongly conservative and limited by boundary condition assumptions. Subsequent studies, including those by Aytekin and Ozguven (2008), Thakur et al. (2015), Béda (2015), Çelik and Genç (2008), Perkins and Sitaraman (2004), Kumar et al. (2017), and Dehbi et al. (2005), have further investigated vibration-induced fatigue phenomena through numerical and experimental analyses, showing that both component type and placement significantly influence lifetime. However, the applicability of these methodologies in industrial contexts remains limited by the specificity of the analyzed cases and by the high computational cost associated with some of them Morettini et al. (2021). In this framework, the objective of the present work is the development of a design support tool for electronic and mechanical engineers capable of providing, given the preliminary configuration of the PCB and the applied loads, a map of the most suitable areas for component placement. The proposed approach integrates structural evaluations from the earliest design phases, enabling a more efficient and reliable co-design process. 2. Stress Mechanisms in Radial-Leaded Components Going into more detail, it is important to note that the variety of electronic components mounted on printed circuit boards is extremely wide but can generally be classified into two main categories based on the mounting technique: Surface Mount Technology (SMT) and Through Hole Technology (THT) (Aytekin and Ozguven (2008), Kumar et al. (2017)). As the name suggests, Surface Mount Technology involves components mounted directly on the surface of the PCB without passing through it. In this configuration, the terminals are soldered onto dedicated copper pads, known as lands or pads, using solder paste and controlled reflow processes. SMT components can be further divided into no lead packages, where electrical contact is achieved through flat surfaces located at the base of the component (Fig. 1a), and leaded packages, which feature small external terminals, typically bent in a “J” shape or as gull wings, as shown in Fig. 1b. This technology enables higher component density, excellent high-frequency performance, and reduced overall assembly weight, making it the most widely adopted solution for large-scale production. Conversely, Through Hole Technology (THT) employs components whose terminals physically pass through the PCB and are soldered on the opposite side. This method is particularly suitable for components of greater mass or those subjected to higher mechanical stresses, such as connectors, relays, and electrolytic capacitors (Dehbi et al. (2005)). THT components can be divided into two main types: radial-leaded components, illustrated in Fig. 1c, in which the terminals exit from the same side of the component (typical of cylindrical capacitors), and axial-leaded components (Fig. 1d), in which the leads extend from opposite sides and pass through the board, Khandpur (2005). Although bulkier and less compatible with automated production, this mounting method remains common in high-reliability applications and in environments subject to strong vibrations (Bhavsar et al. (2014)).