Aluminum Electrolytic Capacitors

Part Number	Description / PDF	Quantity
865060543005 Würth Elektronik Midcom	CAP 47 UF 20% 35 V	489
860010572004 Würth Elektronik Midcom	CAP 33 UF 20% 35 V	1639
860010581024 Würth Elektronik Midcom	CAP 3900 UF 20% 35 V	180
860010372006 Würth Elektronik Midcom	CAP 100 UF 20% 16 V	2353
860010773010 Würth Elektronik Midcom	CAP 22 UF 20% 63 V	1537
860010581025 Würth Elektronik Midcom	CAP 4700 UF 20% 35 V	190
860040375012 Würth Elektronik Midcom	CAP 1200 UF 20% 16 V	98
860010374012 Würth Elektronik Midcom	CAP 470 UF 20% 16 V	795
860010775015 Würth Elektronik Midcom	CAP 120 UF 20% 63 V	486
861111485023 Würth Elektronik Midcom	CAP ALUM 100UF 20% 450V SNAP	45
860010272005 Würth Elektronik Midcom	CAP 100 UF 20% 10 V	3726
860020774014 Würth Elektronik Midcom	CAP ALUM 68UF 20% 63V RADIAL	676
860040474007 Würth Elektronik Midcom	CAP 470 UF 20% 25 V	529
860131178006 Würth Elektronik Midcom	CAP 22 UF 20% 250 V	290
860160374024 Würth Elektronik Midcom	CAP 470 UF 20% 16 V	111
860160574023 Würth Elektronik Midcom	CAP 330 UF 20% 35 V	791
860160280048 Würth Elektronik Midcom	CAP 6800 UF 20% 10 V	0
860160478031 Würth Elektronik Midcom	CAP 1800 UF 20% 25 V	0
861021085019 Würth Elektronik Midcom	WCAP-AIG5 ALUMINUM ELECTROLYTIC	37
860010681031 Würth Elektronik Midcom	CAP 3900 UF 20% 50 V	67

Aluminum Electrolytic Capacitors

1. Overview

Aluminum electrolytic capacitors are polarized capacitors using an aluminum oxide layer as the dielectric medium. They consist of an aluminum anode, electrolyte solution, and cathode. These capacitors offer high capacitance values (1 F-2.7F) with relatively compact size, making them essential components in power supply filtering, signal decoupling, and energy storage applications. Their evolution has enabled miniaturization in electronics while maintaining performance in harsh environments.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Radial Lead Type	Vertical mounting with dual leads	Consumer electronics power supplies
SMD Type	Surface-mount design for PCB integration	Computer motherboards
Stud Mount Type	High-current screw terminal design	Industrial inverters
Bi-polar Type	Able to withstand reverse voltage	Motor drive circuits

3. Structure and Composition

Typical construction includes: - Anode Foil: High-purity aluminum with etched surface (100-600m /m effective area) - Dielectric Layer: 0.1-0.8 m thick aluminum oxide (Al O ) - Electrolyte: Ammonium borate solution in organic solvent - Cathode Foil: 50-100 m aluminum sheet - Separator Paper: 50 m thick kraft paper soaked in electrolyte - Aluminum Case: 0.5-2.0mm thick stamped enclosure

4. Key Technical Specifications

Parameter	Description	Importance
Capacitance (C)	1 F-2.7F (120Hz measurement)	Determines filtering effectiveness
Rated Voltage (UR)	6.3V-630V DC working range	Failure risk above limit
ESR	5m -1.5 at 100kHz	Affects switching performance
Ripple Current	100mA-5A RMS	Lifetime predictor
Leakage Current	0.01C UR A maximum	Power efficiency factor
Operating Temp	-55 C to +150 C range	Reliability indicator

5. Application Fields

Power Electronics: Switching power supplies, UPS systems
Consumer Devices: TVs, gaming consoles, LED lighting
Industrial: Variable frequency drives, welding machines
Automotive: On-board chargers, ADAS systems
Renewables: Solar inverters, wind turbine converters

6. Leading Manufacturers

Manufacturer	Headquarters	Representative Product
Nichicon	Japan	UPW Series (105 C, 2000h)
Rubycon	Japan	ZL Series (Low ESR 4m )
United Chemi-Con	USA	KXJ Series (630V rating)
Samxon	Taiwan	EEU-FR Series (Conductive polymer hybrid)

7. Selection Guidelines

Consider these factors: - Required capacitance tolerance ( 20% standard) - Voltage derating (select 1.25 operating voltage) - Temperature range (automotive requires -40 C to +150 C) - Vibration resistance (screw-terminal better than SMD) - Lifetime calculation: Lx = L0 (T0/ T) (UR/UX) - RoHS compliance for environmental regulations

Industry Trends

Current developments include: - Conductive polymer hybrid capacitors (30% ESR reduction) - Nanoscale dielectric engineering (<0.1 m oxide layers) - AI-driven lifetime prediction models - Bio-compatible electrolyte formulations - 4D printing of anode structures - Integration with PCB substrates

Application Case

In a 3kW server power supply, 4x 450V/470 F capacitors in parallel provide 2220 F total capacitance with 14Arms ripple current handling. The design uses Nichicon U3 series devices with 6.5mm lead spacing, operating at 120 C with 95% voltage derating, achieving 8000-hour MTBF.