When you design a tiny PCB in KiCad and need strong power filtering, the idea of a 20v 1000uf smd 4 x 5.4mm electrolytic capacitor kicad sounds perfect. A 1000 µF capacitor in a super-small 4 mm × 5.4 mm can save huge space on your board. Hobbyists, students, and engineers search for this exact part every day. Sadly, the truth is not so simple. This guide explains everything you need to know in plain words.
What Is the 20V 1000µF SMD 4 x 5.4mm Capacitor?
This capacitor is a surface mount aluminum electrolytic capacitor 20V that should store 1000 microfarads of charge while fitting in a tiny cylinder only 4 mm wide and 5.4 mm tall. In KiCad, the footprint is often named “Capacitor_SMD:C_Elec_4x5.4mm” or similar. Designers love it for:
- Smoothing power rails on small boards
- Decoupling noisy motors or Bluetooth modules
- Bulk storage in battery-powered gadgets
Many people find the footprint in the standard KiCad capacitor footprint library and think, “Great! I’ll just order the part.” That’s where the trouble starts.
Why This Exact Capacitor Is Almost Impossible to Buy
Physics gets in the way. Aluminum electrolytic capacitors need rolled foil and wet electrolyte inside. To reach 1000uF electrolytic capacitor for PCB layout at 20 V, the foil has to be very long. Real manufacturers cannot squeeze that much foil into a 4 × 5.4 mm case without breaking the laws of chemistry and heat.
Here are real sizes you can actually buy in 2025 (data from Panasonic, Nichicon, Rubycon, and KEMET catalogs):
| Capacitance | Voltage | Typical SMD Size (diameter × height) |
| 1000 µF | 16–25 V | 8 × 10 mm or larger |
| 470 µF | 25 V | 6.3 × 7.7 mm (most common small size) |
| 220 µF | 25 V | 4 × 5.4 mm (realistic maximum) |
| 100 µF | 35 V | 4 × 5.4 mm (very common) |
As you see, a true small size electrolytic capacitor 1000uF 20V simply does not exist from reputable makers. Some unknown sellers on AliExpress or eBay list them, but reviews show wrong capacitance, leaking electrolyte, or parts that explode on the board.
For a deeper technical explanation, read this excellent article on Ityug247 and the matching guide on AxeeTech.
Who Needs This Information? (You Are Not Alone!)
- Hobbyists building compact Arduino or ESP32 projects
- Students learning PCB design in KiCad for school assignments
- Makers creating wearables, drones, or tiny power banks
- Engineers working on space-constrained commercial products
- Library maintainers who build or check KiCad electronic components library capacitor entries
If you ever searched for a 20V 1000uF capacitor for compact PCB design or high capacitance SMD capacitor 20V, you belong to this group.
Smart Alternatives That Actually Exist in 2025
Do not give up! Here are proven ways to get the performance you need without fake parts1.
Option 1 – Use a Slightly Bigger Real Capacitor
- 1000 µF 25 V in 8 × 10 mm (still small and cheap)
- Takes only a little extra space but works perfectly
Option 2 – Parallel Smaller 4×5.4mm Capacitors
Two or three 220 µF 25 V 4×5.4 mm capacitors in parallel = 440–660 µF
Add one 330 µF 25 V in 6.3 mm size → total over 900 µF
All fit the original PCB footprint 4×5.4mm capacitor area with tiny layout changes.
Option 3 – Switch to Polymer Capacitors
Modern solid polymer caps offer lower ESR and longer life.
Example: KEMET T598 series 1000 µF 16 V in only 7.3 × 4.3 × 2.8 mm (very flat!).
Option 4 – Low-ESR Ceramic + Small Electrolytic Combo
Many designers now use one 10–22 µF MLCC ceramic + one 220–470 µF electrolytic. This gives excellent ripple filtering in less space.
How to Use the 4×5.4mm Footprint Safely in KiCad
Even if you never buy the “1000 µF miracle”, the footprint is useful.
- Open KiCad → Place a capacitor from the standard library
- Choose Capacitor_SMD:C_Elec_4x5.4mm (or similar)
- In the value field write the real part you will buy, e.g. “220µF 25V”
- Add a note in the silkscreen: “Max realistic 220–330 µF”
- Assign a real manufacturer part number (Panasonic, Nichicon, etc.)
This way your board stays manufacturable and JLCPCB/LCSC will accept it.
Pro tip: Download the latest KiCad capacitor symbol and footprint updates. New libraries mark unrealistic combinations with warnings.
Step-by-Step Guide – Finding Real 4×5.4mm Capacitors in KiCad and LCSC
Follow these exact steps to avoid mistakes:
- Go to LCSC.com or Octopart
- Search “SMD electrolytic 4×5.4” or “D4×5.4”
- Sort by capacitance → you will see the real maximum is around 220–330 µF
- Pick a part from Panasonic FR, Nichicon UCD, or Rubycon ZL series
- Copy the exact footprint name (usually C_Elec_4x5.4mm)
- In KiCad, assign that footprint and manufacturer part number
You now have a small footprint power supply capacitor that actually ships!
Common Mistakes and How to Avoid Them
- Mistake: Trusting a random seller who lists SMD capacitor 4×5.4mm size as 1000 µF → Fix: Always ask for the official datasheet. Real datasheets never show 1000 µF in 4×5.4 mm.
- Mistake: Forgetting polarity on surface mount aluminum electrolytic capacitor 20V → Fix: KiCad footprints have a clear “+” mark and a stripe for the negative side.
- Mistake: Using the footprint for ceramic caps (different pad size) → Fix: Stick to electrolytic footprints only for electrolytic parts.
Quick Comparison Table (Real Parts You Can Buy Today)
| Size (dia × h) | Max Realistic Capacitance @ 25 V | Typical Price (100 pcs) | Example Series |
| 4 × 5.4 mm | 220–330 µF | $0.04–$0.08 | Nichicon UUX |
| 5 × 5.4 mm | 330–470 µF | $0.06–$0.10 | Panasonic FR |
| 6.3 × 5.8 mm | 470–680 µF | $0.08–$0.12 | Rubycon ZL |
| 8 × 10 mm | 1000–2200 µF | $0.15–$0.25 | Any brand |
FAQs About 20V 1000uF SMD 4 x 5.4mm Electrolytic Capacitor KiCad
Does a real 20V 1000µF capacitor in 4 × 5.4 mm actually exist?
No, not from any reputable manufacturer (Panasonic, Nichicon, Rubycon, KEMET, etc.). The laws of physics make it impossible with current electrolytic technology.
Why does KiCad have a 4 × 5.4 mm footprint if the 1000 µF part doesn’t exist?
The PCB footprint 4×5.4mm capacitor is real and widely used — but only for realistic values up to about 220–330 µF. It’s not a promise that 1000 µF fits.
What is the highest real capacitance I can buy in a 4 × 5.4 mm SMD electrolytic?
Around 220 µF to 330 µF at 25 V or 35 V (example: Nichicon UUD1E331MNL1GS or Panasonic EEE-FK1E221P).
I found a 1000 µF 4 × 5.4 mm capacitor on AliExpress/eBay. Is it safe?
Almost certainly fake or relabeled. These parts usually measure 10–50 µF in reality and can leak or explode. Avoid them.
How can I still get close to 1000 µF in a very small space?
- Use two or three 330 µF 4×5.4 mm caps in parallel (total 660–990 µF)
- Or one real 1000uF electrolytic capacitor for PCB layout in the next size up (6.3 × 7.7 mm or 8 × 10 mm)
Which footprint should I use in KiCad for a real 4 × 5.4 mm electrolytic?
Use Capacitor_SMD:C_Elec_4x5.4mm or Capacitor_SMD:CP_Elec_4x5.4 from the official KiCad capacitor footprint library. It’s perfect for 47 µF – 330 µF parts.
How do I find real 4×5.4mm electrolytic capacitor datasheet examples?
Search LCSC.com or DigiKey for “D4.0×5.4” or “4 × 5.4 mm” and filter by capacitance. Top brands: Panasonic FR/FK, Nichicon UUX/UUD, Rubycon ZL.
Conclusion – Stay Safe and Keep Designing
The dream of a 20v 1000uf smd 4 x 5.4mm electrolytic capacitor kicad is very attractive for tiny boards, but real-world parts simply cannot reach that spec yet. Do not risk your project (or your safety) on fake capacitors. Instead, choose proven 220–470 µF parts in the same tiny footprint2, or go just one size larger for true 1000 µF performance.
Your compact design can still succeed — and it will actually work when the boards arrive!
What project are you building that needs such a small high-capacitance capacitor? Share in the comments — we love to help!
References
- AxeeTech – KiCad library analysis and safe alternatives – Great for PCB designers who need manufacturable boards. ↩︎
- Ityug247 – Technical deep-dive on size vs capacitance limits – Perfect for students and hobbyists learning realistic component selection. ↩︎