In industrial machinery, rail transit, aerospace, and automotive engine compartments, severe vibration is a core challenge for EMI feedthrough capacitors—not only can it lead to structural looseness and sealing failure, but it can also cause parasitic parameter fluctuations, degradation of filtering performance, and even permanent damage.
- Core Impacts of Severe Vibration on EMI Feedthrough Capacitors
- Structural Damage: From Loosening to Fracture
-Separation of the center conductor and sealing layer: Under prolonged vibration, gaps, peeling, or even conductor breakage may occur.
-Sealing failure: Epoxy sealing layers may crack due to vibration fatigue, allowing moisture and dust ingress, leading to dielectric layer breakdown.
-Loosening of the housing and panel: Improper installation methods can cause the capacitor housing to detach from the equipment panel, interrupting the grounding path and causing filtering and shielding functions to fail.
- Performance Degradation: Parameter Drift and Filtering Failure
-Parasitic parameter fluctuations: Vibration-induced shifts in internal dielectric layers and conductor positions can degrade high-frequency filtering performance.
-Increased contact resistance: Vibration can lead to oxidation or loosening at connection points between the center conductor and external wiring, raising contact resistance and resulting in signal transmission loss or intermittent disconnections.
-Accelerated dielectric loss: Vibration-induced micro-cracks in ceramic dielectric layers can increase capacitor heating and shorten lifespan.
- Extreme Consequences: System Failures
-Capacitor short/open circuit: Moisture ingress after sealing failure or conductor breakage can cause short or open circuits.
-Uncontrolled electromagnetic interference: Failure of the capacitor’s filtering function allows conducted and radiated noise to interfere with core components, potentially causing system crashes or operational errors.
- Core Vibration-Resistant Design of EMI Feedthrough Capacitors
- Structural Reinforcement: Withstanding Vibration Stress
-Optimized conductor and sealing layers:
- Epoxy sealing: Enhances the toughness of the sealing layer, reducing the risk of peeling under vibration.
- Glass sealing: Prevents cracking of the sealing layer due to temperature fluctuations and vibration.
- Material Selection: Balancing Toughness and Stability
-Dielectric materials: High-mechanical-strength ceramic dielectrics offer better impact and vibration resistance compared to standard ceramics.
-Conductor materials: Center conductors made of copper alloys or Kovar alloys combine conductivity with toughness to prevent breakage under vibration.
Summary: In environments with severe vibration, the core challenge for EMI feedthrough capacitors is ensuring both structural reliability and performance stability. By optimizing sealing processes, reinforcing structural designs, selecting high-toughness materials, and adhering to vibration-resistant selection standards, the risks of damage and performance degradation caused by vibration can be effectively mitigated. For applications such as industrial, rail transit, and aerospace, where reliability requirements are extremely high, vibration-resistant design has become one of the core technical barriers for LCA® EMI feedthrough capacitors and a key factor in ensuring the electromagnetic compatibility performance of equipment.
