Avoiding Common Capacitor Mishaps: Why Passive Component Selection Matters More Than You Think

When it comes to circuit design, especially in printed circuit board (PCB) development, much of the spotlight shines on active components like processors, memory, and specialized ICs. But tucked away in the corners of every board are unsung heroes: discrete passive components—resistors, inductors, and yes, capacitors.

It’s easy to underestimate their impact, but capacitor selection and sourcing can make or break a design. Here’s why this often-overlooked stage deserves more attention.

1. The Illusion of Simplicity

Capacitors are frequently seen as basic building blocks—commodities that can be plugged in with little thought. But that assumption hides a complex reality. Critical specs like:

• Capacitance tolerance

• Dielectric material (e.g., X7R, NP0, Y5V)

• ESR (Equivalent Series Resistance)

• Voltage rating

...can drastically affect circuit performance, especially in power delivery networks, signal filtering, or high-frequency designs. Selecting the wrong type can lead to instability, noise, or premature failure.

2. Relying on Default BOMs or Library Parts

Designers working within CAD tools often default to components from standard libraries or past projects. While this saves time upfront, it can lead to big headaches later when a selected capacitor turns out to be:

• Obsolete (EOL)

• On allocation with 52-week lead times

• Incompatible with regulatory or reliability specs

Proactive sourcing—ensuring the component is available, qualified, and future-proof—is essential for avoiding redesigns and delays.

3. The Supply Chain Isn’t What It Used to Be

Once upon a time, capacitors were “always in stock.” Not anymore.

In today’s tight and volatile supply chain environment, even the most common capacitor values may become hard to source. And with certain dielectrics or temperature ratings in high demand, early coordination with sourcing teams or reliable distributors can save your project from production stalls.

4. Performance on the PCB Isn’t Just About Specs

On the datasheet, a capacitor may look perfect—but on your PCB, layout choices matter just as much. Factors like:

• Trace and via parasitics

• Proximity to power pins

• Stack-up and ground return paths

…affect real-world performance, especially for decoupling, filtering, or noise suppression. A poorly placed or selected capacitor can lead to EMI, ringing, or power integrity issues that are hard to debug and expensive to fix.

5. Special Requirements? Special Considerations

In mission-critical applications—think aerospace, medical, automotive, or industrial—capacitors must meet:

• MIL-spec or AEC-Q200 standards

• Wide temperature tolerances

• Hermetic sealing or screening

Designers who skip over these requirements during the selection phase risk non-compliance, test failures, or in-field reliability issues.

Key Takeaways

Capacitors might seem like simple components, but they carry serious design weight. To avoid costly mishaps:

✅ Don’t treat passives as interchangeable commodities
✅ Coordinate with sourcing teams early
✅ Match component specs to real-world performance needs
✅ Plan for long-term availability and compliance

By giving capacitors—and other passives—the attention they deserve during the selection and sourcing process, you can elevate the reliability and success of your entire PCB design.

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What Are Electrolytic and Ceramic Capacitors?

Electrolytic and ceramic capacitors are two common types of capacitors, each with distinct characteristics and applications.

Electrolytic Capacitors

• Construction: Made with an electrolyte (a liquid or gel substance) as one of the electrodes, allowing for higher capacitance values.

• Polarity: Typically polarized, meaning they have a positive and negative terminal and must be connected correctly in a circuit.

• Capacitance Range: Usually ranges from 1µF to several thousand µF.

• Voltage Ratings: Typically from a few volts to a few hundred volts.

• Applications: Used in power supply filtering, energy storage, and signal coupling in audio and power circuits.

• Types:

  • Aluminum Electrolytic – Most common, used in power applications.

  • Tantalum Electrolytic – More stable and compact but expensive.

Ceramic Capacitors

• Construction: Uses a ceramic dielectric material with metal plates on either side.

• Polarity: Non-polarized, so they can be connected in any direction.

• Capacitance Range: Typically pF (picofarads) to low µF range.

• Voltage Ratings: Can range from a few volts to several kV.

• Applications: Used in high-frequency circuits, filtering, decoupling, and timing applications.

• Types:

  • MLCC (Multilayer Ceramic Capacitors) – Common in surface-mount applications.

  • Disc Ceramic – Used in general-purpose applications.

Key Differences

For aerospace and military applications, capacitors must meet stringent requirements for reliability, temperature tolerance, and durability under extreme conditions. Below are recommendations for both electrolytic and ceramic capacitors suitable for these environments:

1. Electrolytic Capacitors (High-Reliability Applications)

Electrolytic capacitors are often used in power supplies, filtering, and energy storage where high capacitance is required.

Recommended Types:

• Tantalum Capacitors (Mil-Spec)

  • Example: MIL-PRF-55365-compliant solid tantalum capacitors

  • Pros: Excellent stability, low ESR (Equivalent Series Resistance), long lifespan.

  • Cons: Sensitive to voltage spikes, more expensive.

  • Applications: Avionics power circuits, radar systems, mission-critical electronics.

• Hermetically Sealed Aluminum Electrolytic Capacitors

  • Example: MIL-PRF-39018 or MIL-PRF-49470

  • Pros: High capacitance, ruggedized for harsh conditions.

  • Cons: Larger size, lower lifespan than tantalum.

  • Applications: Military-grade power filtering, bulk energy storage in aerospace electronics.

2. Ceramic Capacitors (High-Frequency & Temperature-Stable Applications)

Ceramic capacitors are ideal for high-frequency filtering, decoupling, and RF/microwave applications due to their low loss and stability.

Recommended Types:

• High-Reliability MLCCs (Multilayer Ceramic Capacitors)

  • Example: MIL-PRF-123 or MIL-PRF-55681 qualified MLCCs

  • Pros: Excellent stability, high reliability, wide temperature range (-55°C to +200°C).

  • Cons: Lower capacitance compared to electrolytic.

  • Applications: RF communications, missile guidance systems, avionics.

• Radial Leaded or Stack Capacitors

  • Example: High-voltage MLCCs for radar and power systems

  • Pros: Withstands extreme conditions, radiation-hardened variants available.

  • Applications: Satellite electronics, pulse power circuits in military defense systems.

Key Selection Factors for Aerospace/Military Use:

✅ Temperature Tolerance – Components should operate reliably in extreme environments (-55°C to +125°C or higher).
✅ Shock & Vibration Resistance – MIL-spec capacitors should meet MIL-STD-202 testing for ruggedness.
✅ Radiation Hardening – Essential for space applications to prevent degradation from cosmic radiation.
✅ Low ESR/ESL – Critical for high-frequency filtering in radar, avionics, and RF applications.

Vishay offers a comprehensive range of capacitors tailored for aerospace and military applications, ensuring high reliability and performance under stringent conditions. Below are specific recommendations for both electrolytic and ceramic capacitors:

1. Electrolytic Capacitors

a. STH SuperTan® Wet Tantalum Capacitors

• Features:

  • Enhanced performance with military H-level shock (500 g) and vibration capabilities (sine: 80g; random: 54 g).

  • Hermetic glass-to-metal seals for improved reliability.

  • Suitable for avionics and aerospace applications requiring high capacitance and energy density.

• Applications:

  • Ideal for use in avionics, aerospace, and defense systems where robust performance is critical.

• Additional Information:

  • These capacitors are designed to withstand harsh environmental conditions, making them suitable for mission-critical applications.

b. High-Reliability Aluminum Electrolytic Capacitors

• Features:

  • Designed for military and aerospace applications with extended operational life and stability.

  • Available in various configurations, including axial and radial leaded, to accommodate different design requirements.

• Applications:

  • Used in power supplies, energy storage, and filtering applications within military and aerospace systems.

• Additional Information:

  • These capacitors comply with military specifications, ensuring reliability in critical operations.

2. Ceramic Capacitors

a. MIL-PRF-123 Qualified Multilayer Ceramic Chip Capacitors

• Features:

  • Space-level reliability with military qualification.

  • Suitable for applications requiring high performance and reliability under extreme conditions.

• Applications:

  • Ideal for use in space systems, satellite communications, and military avionics.

• Additional Information:

  • These capacitors are designed to meet stringent military standards, ensuring optimal performance in critical applications.

b. CDR Series (MIL-PRF-55681) Multilayer Ceramic Capacitors

• Features:

  • Compliant with MIL-PRF-55681 standards, ensuring high reliability.

  • Available in various case sizes and voltage ratings to suit diverse application needs.

• Applications:

  • Commonly used in military communication equipment, radar systems, and aerospace controls.

• Additional Information:

  • These capacitors offer stable performance across a wide temperature range, making them suitable for harsh environments.

Key Selection Factors:

• Compliance with Military Standards: Ensure capacitors meet relevant MIL specifications (e.g., MIL-PRF-123, MIL-PRF-55681) for reliability.

• Environmental Tolerance: Select capacitors capable of withstanding extreme temperatures, shock, and vibration.

• Electrical Performance: Consider capacitance stability, equivalent series resistance (ESR), and voltage ratings appropriate for the application.

Need a trusted partner for Electrolytic or Ceramic Capacitors? Contact us today and let’s solve obsolescence together.

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Why Engineers Should Consider Using Vishay Intertechnology MLCC Capacitors

Manufactured using a cost-efficient base metal electrode (BME) system and dry sheet technology, these MLCCs provide an affordable solution for various high-voltage applications.

Vishay Intertechnology Expands High Voltage MLCC Offerings with Increased Capacitance for Commercial Applications

Vishay Intertechnology, Inc. has introduced a new series of surface-mount multilayer ceramic chip capacitors (MLCCs) designed for high-voltage commercial applications. Available in seven compact case sizes ranging from 1206 to 2225, the VJ….W1HV High Voltage MLCC Commercial Series enhances Vishay’s existing lineup by offering extended capacitance options. These capacitors utilize the ultra-stable C0G (NP0) dielectric and are also available with the X7R dielectric for even greater capacitance levels.

Manufactured using a cost-efficient base metal electrode (BME) system and dry sheet technology, these MLCCs provide an affordable solution for various high-voltage applications. They are ideal for input and output filtering, as well as snubber capacitors in sectors such as renewable and conventional energy systems, power distribution, industrial automation, motor drives, power tools, welding equipment, telecom infrastructure, consumer appliances, and medical instrumentation.

Key specifications include:

• C0G (NP0) versions: Voltage ratings up to 3000 VDC, capacitance values ranging from 1.5 pF to 82 nF, and a temperature coefficient of capacitance (TCC) of 0 ppm/°C ±30 ppm/°C from -55 °C to +125 °C.

• X7R versions: Capacitance ranging from 100 pF to 100 nF, voltage ratings up to 2000 VDC, and a TCC of ±15% over the same temperature range.

• Reliable construction: Featuring nickel barrier with 100% tin terminations, these capacitors are also available with polymer terminations to prevent damage from board flexure.

Additionally, the VJ….W1HV series meets environmental standards by being RoHS-compliant, halogen-free, and Vishay Green.

Why Engineers Should Consider These MLCCs

1. Extended Capacitance for High-Voltage Applications

• Engineers working on power electronics, renewable energy systems, and industrial automation can benefit from the increased capacitance range and high-voltage ratings, making these capacitors suitable for demanding applications.

2. Reliable Performance in Extreme Conditions

• The ultra-stable C0G dielectric ensures minimal capacitance drift over a wide temperature range, while the X7R dielectric offers higher capacitance for designs requiring more energy storage.

3. Cost-Effective Solution

• With a BME system and dry sheet technology, these capacitors offer an affordable alternative without compromising on quality, making them a practical choice for large-scale production.

4. Enhanced Durability and Board Protection

• Engineers designing circuits with potential mechanical stress can opt for polymer terminations, reducing the risk of cracks and failures due to board flexure.

5. Eco-Friendly and Industry-Compliant

• Being RoHS-compliant and Vishay Green, these MLCCs align with modern environmental and safety standards, ensuring sustainable product development.

Conclusion

These features make the VJ….W1HV High Voltage MLCC Series a strong candidate for engineers seeking a high-performance, cost-effective, and durable capacitor solution for their next-generation designs. Discover the collection of MLCC capacitors from Vishay Intertechnology.
Let us help you find the perfect capacitor to elevate your applications and ensure optimal performance.

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Avoid These Common Capacitor Failures

Capacitors are crucial in circuit design, yet they’re often overlooked—until they fail. As key components in power, RF, digital, and analog circuits, capacitors are frequently exposed to voltage surges, transients, and harsh environmental conditions. Neglecting their selection and protection can lead to early failures, sometimes catastrophic ones.

Why Capacitors Fail

Capacitors serve critical functions, from filtering noise to voltage regulation. However, they are vulnerable to:

• Overvoltage & Transients: Surges, especially in industrial, military, and aerospace applications, can exceed a capacitor’s limits.

• Temperature Extremes: Heat and cold affect dielectric integrity, accelerating degradation.

• Wear & Tear: Over time, capacitors can leak, corrode, or even explode due to internal pressure buildup.

• Mechanical Stress: Shock and vibration may damage delicate internal structures, particularly in through-hole capacitors.

Designing for Reliability

To extend capacitor lifespan and prevent failure:

• Choose Higher Ratings: Select capacitors with voltage and temperature margins above expected conditions.

• Optimize Placement: Keep them away from heat sources or use shielding for thermal protection.

• Consider Ruggedized Components: Use capacitors designed for extreme environments or reinforced with vibration-dampening materials.

• Ensure Proper Mounting: Utilize 3D space efficiently to accommodate higher-current components.

Conclusion

Capacitors are essential to the functionality of modern electronics, but their performance hinges on making the right choice and ensuring they’re properly protected. By accounting for real-world factors like voltage spikes, heat, and mechanical stress, you can significantly extend the lifespan of your circuits and avoid costly failures down the road.

Serving as the backbone of electronic systems, capacitors are crucial for controlling current flow and shielding sensitive components. Selecting the right capacitor is not just important—it’s vital to the success of any project. Whether you’re an engineer, hobbyist, or tech enthusiast, mastering capacitor selection empowers you to push the boundaries of your designs. Discover our top-tier collection of capacitors from leading manufacturers—Knowles/Novacap, Vishay EFI, Vishay Sprague, and Vishay Vitramon—available exclusively through ES Components. Let us help you find the perfect capacitor to elevate your applications and ensure optimal performance.

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