Jianghai Europe has outlined a set of design and mounting measures that significantly increase the vibration stability of radial aluminum e‑caps, helping design engineers and purchasers achieve higher reliability in the field.
Radial aluminum electrolytic capacitors in machine tools and other harsh industrial environments are exposed to continuous vibration, shocks and resonances that can lead to premature failure. This article summarizes the key points and translates them into practical guidance for real-world designs.
Why vibration stability matters
In applications such as machine tool manufacturing, the circuit board is subjected to strong vibrations, mechanical shocks, oscillations and structural resonances that are transferred directly into mounted capacitors. Larger radial electrolytic capacitors are especially critical because their can mass acts as a mechanical flywheel that stresses the solder joints and internal connections. Without appropriate mechanical design and mounting concepts, this can result in cracked leads, internal disconnections and ultimately field failures.
Key design aspects and benefits
There are two main dimensions determine whether a radial electrolytic capacitor will survive in a high‑vibration environment: how it is mounted in the equipment and how the internal structure is engineered.
Mounting of components on the PCB or in the housing
The responsibility for robust mounting typically lies with the hardware development team.
Key considerations include:
- Ensuring that the leads are not used as mechanical springs
- Capacitors should be fixed so that the connections are not continuously bent or fatigued by vibration.
- Evaluating additional mechanical fixation methods
- If gluing is used, heat dissipation through the sleeve and to the surroundings must be verified so that the component does not overheat.
- Even firmly glued heat‑shrink tubing around the can does not automatically guarantee long‑term fixation of the can to the board or chassis.
- Analysing the installation position and vibration direction
- Axial forces (along the capacitor axis) and radial forces (perpendicular to the axis) excite different vibration modes and lead to different stress patterns.
- Orientation, clearance to neighbouring components and proximity to mounting screws or stiffeners affect the actual mechanical load.
When designing layouts and mechanical fixtures, engineers should therefore:
- Place heavy radial capacitors near mechanical supports or stiff parts of the PCB.
- Avoid mounting them at the free end of long, flexible boards.
- Consider additional brackets, clamps or adhesive points that transfer mass forces away from the solder joints.
Internal layout of the components
The capacitor manufacturer controls the internal mechanical robustness of the component.
Important optimisation questions include:
- Film system and mechanical robustness
- How thick and mechanically break‑resistant are the aluminum foils and separator materials.
- Number and robustness of internal connections
- Whether the number of internal tabs and welds can be increased to improve stability of the current path and reduce the risk of internal open circuits.
- Additional protective layers
- Whether extra paper layers or similar measures are used to cushion and protect sensitive regions of the winding.
- Fixation of the internal cell relative to the can
- How securely the wound element is fixed inside the case so that shocks do not allow it to move relative to the housing.
Over the lifetime of an electrolytic capacitor, the winding gradually dries and shrinks, reducing its weight and altering its mechanical resonance frequency. A design that passes vibration tests on fresh samples can behave differently after years of operation if the internal fixation is inadequate. Avoiding any relative movement between the inner cell and the can is therefore a central design target for high‑vibration applications.
Typical applications
Radial electrolytic capacitors with enhanced vibration stability are particularly relevant wherever:
- Machine tools and CNC equipment generate continuous mechanical vibration.
- Industrial drives, pumps and compressors cause structural resonances in control cabinets.
- Power supplies or control units are mounted directly on vibrating motors or actuators.
- Transportation and off‑highway equipment expose electronics to shocks and impact loads.
In such environments, these capacitors are typically used in:
- DC bus buffering and intermediate circuits of motor drives.
- Input and output filtering of switched‑mode power supplies.
- Local energy storage in control boards, I/O modules and sensor interfaces.
By specifying parts and mounting concepts optimized for vibration resistance, design teams can extend service life and reduce the risk of intermittent failures that are difficult to diagnose in the field.
Technical highlights
Although the press information focuses on mechanical aspects rather than specific catalog series, some general technical highlights of Jianghai’s vibration‑optimized radial e‑caps can be summarized in engineering terms as:
- Internal mechanical design tailored for high vibration and shock conditions, with special attention to foil robustness, internal interconnections and winding fixation.
- Construction intended to minimize relative motion between the wound element and the can across the component lifetime, even as the electrolyte gradually dries and the winding shrinks.
- Compatibility with common industrial operating conditions, subject to detailed ratings and endurance data given in the relevant manufacturer datasheets.
Exact values for voltage range, capacitance values, temperature range, endurance and vibration test levels should be taken from the specific Jianghai radial e‑cap datasheets for the target series.
Design‑in notes for engineers
When designing radial electrolytic capacitors into high‑vibration applications, engineers can use Jianghai’s guidance as a practical checklist.
During schematic and component selection
- Identify all positions subjected to increased mechanical stress
- Components on large, flexible boards or located near strong vibration sources are candidates for vibration‑robust types.
- Discuss mechanical requirements with the capacitor supplier early
- Define expected vibration spectra, shock levels and lifetime so the supplier can recommend suitable series and mechanical options.
- Use datasheets for concrete limits
- Maximum vibration acceleration, frequency ranges and endurance test conditions should be taken “as per manufacturer datasheet” for the chosen series.
During PCB and mechanical design
- Avoid relying solely on solder joints for mechanical support
- For larger can sizes, combine soldering with mechanical fixation (e.g., adhesive spots, brackets or clamps) while keeping thermal paths in mind.
- Consider the direction of main vibration
- Align radial capacitors and place them so that the dominant vibration direction excites the mechanically more robust mode whenever possible.
- Validate with realistic tests
- If the application is highly demanding, perform vibration tests not only on new samples but also on aged parts, since resonance behavior can shift over time.
Collaboration between developers and manufacturers
Jianghai Europe emphasizes that robust solutions in high‑vibration environments come from early, targeted dialogue between the development team and the capacitor manufacturer. For critical projects, it is advisable to:
- Share mechanical boundary conditions, fixing concepts and operating profiles with the supplier.
- Review proposed mounting concepts and internal layouts together.
- Agree on test plans (vibration, shock and endurance) that reflect real‑world use rather than minimum standard requirements.
This approach helps avoid unpleasant surprises in the field and ensures that the capacitor design and its mounting concept form a coherent, robust system.
Source
This article is based on a Jianghai Europe press release describing the design and application aspects of extremely vibration‑resistant radial aluminum electrolytic capacitors, supplemented with neutral engineering commentary for design‑in and component selection.
