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When a multilayer ceramic capacitor (MLCC) is soldered on a printed circuit board (PCB), the capacitor deformation generates a force on the PCB, which serves as a source to excite PCB vibration and generate unwanted acoustic noise. A MLCC can be used under any loading conditions as long as the power supply voltage remains below its rated voltage; thus, the MLCC source mode can be extremely complicated because of different combinations including direct current voltage levels, alternating current noise amplitudes, and related frequencies. When the power rail is under different loading conditions, the PCB vibration amplitude can differ; however, the MLCC vibration source model should remain the same under a given condition. In this article, the MLCC equivalent source models are developed with a simplified method, and a source model library for the six MLCCs is constructed. A method for simplifying the MLCC equivalent source model is addressed from three aspects: frequency, power supply dc voltage, and ac noise amplitude. The developed source model library is validated by comparing the simulated and measured system vibration velocity. The proposed simplification method can significantly reduce model development efforts and enable the creation of a comprehensive source model library for MLCCs.

Multilayer ceramic capacitors (MLCCs) are commonly used on printed circuit board (PCB) power distribution networks (PDN) for decoupling purposes. However, an MLCC can act as a source to excite PCB vibrations due to noise ripples on the power rail. In this letter, four types of equivalent source configurations are studied and compared to represent the excitation of an MLCC on a PCB driven by power rail noise. The corresponding source values are extracted at test-vehicle PCB resonance frequencies. The investigation of the four equivalent source types involves a comparison between simulated and measured PCB vibration velocity responses triggered by MLCC deformation across an audible frequency band. The advantages of each equivalent source are discussed for specific application scenarios.

On-board electrical components can cause printed circuit board (PCB) vibration, thus generating audio noise if the electrical noise is in the audible frequency range. The electrical component-induced vibration can be equated to an external force applied to the PCB. This article presents a novel methodology to extract the equivalent force of electrical components on a PCB to study board vibration and potential acoustic noise problems. The method is based on a combination of measurement and simulation, wherein PCB vibration is used as the medium in the extraction process. The methodology is validated by the correlation of PCB vibration pattern, frequency, and amplitude with a known electromagnetic force applied to the PCB.