8min Readtime
Published Aug 23, 2025
Many capacitor failures don’t show up until after mass production — swelling, leakage, or shortened lifespan that appear only in real-world use.
And often, the problem isn’t poor quality at all.
👉 It’s small, easily overlooked details — placement and hidden internal mechanisms.
Even a capacitor rated 2000 hours @ 105°C behaves very differently depending on where it’s used:
💨 Well-ventilated: Full rated lifespan
🔥 Near heat source: Lifespan cut in half
🧱 Enclosed space with heat buildup: Drops to 25%
📉 Every 10°C rise in core temperature roughly halves capacitor life.
That’s why evaluating the thermal environment during design is just as critical as selecting the right part number.
Once failures appear in production, the cost isn’t just a capacitor — it’s rework, delays, and customer complaints.
Even when placement is correct, there’s another silent risk — capacitors that pass all tests but still fail in the field.
This often traces back to a subtle mechanism called Delayed Short Failure (DSF).
Inside an aluminum electrolytic capacitor, microscopic conductive particles (such as aluminum flakes or foil dust) may remain from production.
These can pass:
✅ Electrical inspection
✅ Burn-in and aging screening
…but later migrate under electric field, heat, or vibration until they bridge both electrodes — creating a short circuit.
This is more common in:
Ultra-low impedance capacitors (thinner separators)
High-capacitance / high-voltage types (higher stored energy)
Once a short occurs → rapid temperature rise → bulging → possible rupture or explosion.
Both thermal design and internal structure control play a decisive role in long-term reliability.
Selecting higher-temp or longer-life series, verifying layout ventilation, and working with manufacturers that manage particle contamination can dramatically reduce risk.
📩 If your capacitor seems “right,” but the results aren’t — let’s talk.
Sharing experience helps the whole industry move toward safer, longer-lasting designs.
