关键词: CAK45型片式钽电容器, 点胶加固工艺, 随机振动, 正弦振动

Abstract: This study focuses on the reliability issues of CAK45 chip tantalum capacitors under aerospace vibration environments, and has designed PCB boards incorporating various types of tantalum capacitors, and GD414 silicone rubber was applied for structural reinforcement through dispensing techniques. Experimental and numerical simulation methods validated the optimized dispensing process and reliability. Results indicate that under both random and sinusoidal vibration loads, all tested capacitor-PCB assemblies exhibited higher vibration energy at low frequencies with significant high-frequency attenuation, though their response characteristics differed. During random vibration, the power spectral density (PSD) showed linear increase in the 0-100 Hz range, significant fluctuations between 100-600 Hz causing stress concentration at capacitor-PCB interfaces leading to solder joint failure and capacitor cracking, and substantial decrease beyond 600 Hz. Under sinusoidal vibration, notable PSD fluctuations occurred along both Y and Z directions, with vibration energy concentrated primarily in the 10-40 Hz low-frequency range and pronounced high-frequency attenuation observed between 50-70 Hz. Under sinusoidal vibration, the PCB board with Type B tantalum capacitors exhibits the poorest resistance to Y-direction vibration, while the PCB board with Type D tantalum capacitors shows the best resistance to Y-direction vibration, and the PCB board with Type H tantalum capacitors has the poorest resistance to Z-direction vibration. Numerical simulations confirmed that GD414 dispensing reinforcement effectively enhances capacitor vibration resistance, distributes vibrational stress to the circuit board, and significantly reduces stress on solder joints.

Key words: CAK45 tantalum chip capacitor, potting reinforcement process, random vibration, sinusoidal vibration