Aluminum Electrolytic Capacitors

Part Number	Description / PDF	Quantity
860020473010 Würth Elektronik Midcom	CAP ALUM 150UF 20% 25V RADIAL	84
865080340002 Würth Elektronik Midcom	CAP 15 UF 20% 16 V	165
860010373007 Würth Elektronik Midcom	CAP 120 UF 20% 16 V	128
860010375015 Würth Elektronik Midcom	CAP 680 UF 20% 16 V	125
860021378013 Würth Elektronik Midcom	CAP ALUM 22UF 20% 400V RADIAL	300
865080563018 Würth Elektronik Midcom	CAP 1500 UF 20% 35 V	70
865090340001 Würth Elektronik Midcom	CAP 4.7 UF 20% 16 V	1778
860240675007 Würth Elektronik Midcom	CAP 100 UF 20% 50 V	667
860021374009 Würth Elektronik Midcom	CAP ALUM 6.8UF 20% 400V RADIAL	5443
860080678021 Würth Elektronik Midcom	CAP ALUM 680UF 20% 50V THRU HOLE	242
865060162012 Würth Elektronik Midcom	CAP 3300 UF 20% 6.3 V	0
865080562017 Würth Elektronik Midcom	CAP 680 UF 20% 35 V	76
860010480022 Würth Elektronik Midcom	CAP 2700 UF 20% 25 V	0
860020575016 Würth Elektronik Midcom	CAP ALUM 680UF 20% 35V RADIAL	184
860011375006 Würth Elektronik Midcom	CAP 10 UF 20% 400 V	12
860020575014 Würth Elektronik Midcom	CAP ALUM 470UF 20% 35V RADIAL	679
860040578014 Würth Elektronik Midcom	CAP 1000 UF 20% 35 V	279
860020572003 Würth Elektronik Midcom	CAP ALUM 10UF 20% 35V RADIAL	2207
860160674022 Würth Elektronik Midcom	CAP 120 UF 20% 50 V	800
860010380024 Würth Elektronik Midcom	CAP 3900 UF 20% 16 V	0

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.