Thermal Crosstalk and Dependent Failures: Redefining MLCC Reliability in High-Density Circuits

As modern electronics continue to evolve, the demand for miniaturization and high-density circuit integration has led to an increasing reliance on multilayer ceramic capacitors (MLCCs). These components serve essential roles in electrical circuits, including energy storage, noise filtering, and voltage regulation. However, as MLCCs are packed more closely together in circuit boards, new reliability challenges arise. One of the most critical issues is the phenomenon of thermal crosstalk, where the heat generated by one component affects the performance and degradation rate of its neighboring components. This effect is particularly concerning in applications requiring prolonged operational stability, such as aerospace, automotive electronics, and high-power computing systems. Traditionally, the failure of MLCCs has been studied in isolation, with each component assumed to degrade independently under applied electrical and thermal stresses. However, real-world circuit environments introduce dependent failure mechanisms, where failures in one component can accelerate the degradation of nearby MLCCs. Among the many degradation pathways, oxygen vacancy electromigration plays a dominant role, leading to reduced insulation resistance over time and ultimately causing premature failure. The conventional highly accelerated lifetime testing (HALT) methodology, widely used for reliability assessments, often assumes that failures occur independently. This assumption overlooks the impact of thermal interactions, which can create common cause failures (CCFs)—a shared failure mode driven by thermal stress propagation across closely spaced MLCCs. Given the growing complexity of modern electronic circuits, there is an urgent need to reevaluate MLCC failure mechanisms within the broader context of circuit layout and component spacing. A more refined approach is required—one that integrates Physics of Failure (PoF) models, advanced finite element thermal simulations, and real-time infrared thermography to capture the full scope of thermal interactions within MLCC arrays. Without a deep understanding of these dependencies, reliability predictions remain incomplete, potentially leading to inaccurate estimations of component lifespan and unexpected failures in mission-critical applications.

To this account, new research paper published in Journal of Applied Physics and led by Professor Clive Randall from Pennsylvania State University and contributed by Dr.  Pedram Yousefian; Dr.  Daniel Shoemaker; Dr.  Javier Mena-Garcia; Dr.  Michael Norrell; Dr.  Jeff Long; and Dr. Sukwon Choi., researchers quantify the impact of thermal crosstalk on MLCC reliability and to differentiate between independent and dependent failure rates in closely packed configurations. By leveraging a combination of experimental HALT data, thermal imaging techniques, and statistical failure modeling, this research aims to establish a framework for predicting common cause failures in MLCC networks. The study introduces the β0 factor, a statistical metric used to quantify the extent to which a failure in one component increases the likelihood of failure in adjacent components. By examining MLCC arrays with varying spacing, voltage conditions, and temperature profiles, this research seeks to offer practical insights into optimal PCB layout design for mitigating failure risks.

The researchers examined the impact of thermal crosstalk on the failure rates of MLCCs under accelerated lifetime testing conditions. They began by designing circuit boards with different component spacings—some with narrow gaps between capacitors, others with moderate spacing, and a final group with wider separations. These variations allowed them to observe how proximity influenced failure patterns, especially in environments where heat buildup was a concern. Once the MLCCs were mounted onto these boards, the team subjected them to HALT, applying high voltage and temperature stress to simulate long-term operation in a much shorter timeframe. As the tests progressed, clear differences emerged in how the capacitors degraded. In the tightly packed circuits, failures occurred significantly faster, suggesting that heat generated by one MLCC was amplifying the degradation of its neighbors. To quantify this effect, the researchers used infrared thermography, a technique that visualizes heat distribution across the board in real time. These thermal images confirmed that the capacitors in close proximity experienced higher temperatures than those in more spaced-out configurations. The central capacitors in densely packed layouts showed the most severe heating, while those near the edges had slightly lower thermal exposure. This demonstrated that thermal crosstalk was a real and measurable contributor to component failure, particularly in high-density circuit designs. To further validate their findings, the researchers developed finite element thermal models, simulating how heat was transferred within the circuit board under different conditions. These models closely matched the experimental results, reinforcing the conclusion that dependent failures—where one component’s failure accelerates another’s—were largely driven by heat accumulation. The authors also applied statistical methods to calculate the β0 factor, a measure of how much one capacitor’s failure increased the likelihood of another’s. For boards with narrow component spacing, the β0 factor was significantly higher, indicating that these circuits were far more vulnerable to cascading failures. In contrast, the widest-spaced circuits exhibited far lower dependent failure rates, supporting the idea that thermal isolation between components improves long-term reliability. An unexpected but crucial observation came when they looked at the role of voltage in failure acceleration. While higher voltages naturally contribute to faster degradation, they found that in boards with significant thermal crosstalk, increasing voltage amplified the failure clustering effect. Essentially, capacitors that might have failed independently in a well-spaced layout were instead failing in clusters when subjected to both high voltage and thermal interaction. This was a key takeaway for circuit designers, as it highlighted the importance of both electrical and thermal design considerations in preventing early failure.

In conclusion, Professor Clive Randall and his colleagues demonstrated that thermal crosstalk accelerates dependent failures, this research challenges the conventional assumption that MLCC failures occur independently. It provides strong empirical and theoretical evidence that heat buildup in densely packed circuits is not just an efficiency concern—it’s a fundamental risk factor that shortens component lifespan and leads to premature failure clustering. For circuit designers and engineers, these findings redefine best practices in PCB layout optimization. Many industries, from consumer electronics to aerospace and automotive manufacturing, are pushing toward smaller, more powerful devices, increasing the likelihood of thermal crosstalk. The study highlights the necessity of strategic spacing between components, showing that even slight increases in separation can significantly reduce failure rates. This insight allows manufacturers to fine-tune their designs to balance performance, size constraints, and reliability, rather than relying solely on conventional HALT-based lifetime predictions that overlook heat-induced dependencies.

The implications also extend into materials science and capacitor engineering. The study suggests that reducing oxygen vacancy electromigration, which contributes to heat-induced failure, could be further mitigated by improved material formulations or alternative capacitor architectures that dissipate heat more efficiently. Future research may focus on developing advanced ceramic dielectrics or integrating passive cooling structures directly into MLCC designs to counteract the thermal clustering effect. On the industry side, the new work could lead to revised design standards and qualification tests for electronic components, particularly in automotive and aerospace systems where reliability under high stress is non-negotiable. Instead of treating HALT as a one-size-fits-all approach, manufacturers may need to implement thermal-crosstalk-aware testing protocols, ensuring that new circuit designs are robust against real-world heat distribution challenges. We think the study bridges the gap between empirical failure data and practical design improvements, giving engineers the tools to build more resilient, long-lasting electronic systems. By recognizing thermal crosstalk as a major factor in dependent failures, it paves the way for safer, more reliable, and better-optimized electronic devices, meeting the demands of modern technology without compromising on durability.