The Production & Storage of Aluminum Electrolytic Capacitors: A Comprehensive Guide

Introduction

Aluminum electrolytic capacitors play a vital role in the electronics industry, powering a wide range of devices from smartphones to industrial equipment. Understanding their production process and proper storage conditions is crucial for manufacturers, suppliers, and end - users alike. This article will delve into the intricate production steps of aluminum electrolytic capacitors and detail the necessary storage conditions to ensure their optimal performance.

 

 

The Production Process of Aluminum Electrolytic Capacitors

1. Preparation of Materials 

Aluminum Foil: High - purity aluminum foil is the primary material. It is carefully selected for its purity and physical properties. The aluminum foil is then etched to increase its surface area. This is achieved through a chemical process where the foil is immersed in an acidic solution. The etching process creates a rough, porous surface on the aluminum foil, which significantly increases the capacitance of the capacitor.

- Electrolyte: The electrolyte is a crucial component. It is usually a mixture of organic solvents, such as ethylene glycol or propylene glycol, and dissolved salts, like ammonium borate or potassium borate. The electrolyte is formulated to have good electrical conductivity and chemical stability.

 

2. Formation of the Anode

The etched aluminum foil is then used to form the anode. It is oxidized in an anodizing bath, which is typically a solution of boric acid and ammonium borate. An electric current is passed through the foil in this bath, causing a thin layer of aluminum oxide to form on the surface of the foil. This aluminum oxide layer serves as the dielectric in the capacitor, which is essential for its ability to store electrical charge.

 

3. Preparation of the Cathode 

The cathode is usually made from a less - expensive aluminum foil. This foil may also undergo some surface treatment to improve its conductivity and contact with the electrolyte. A separator, often made of a porous material like paper or non - woven fabric, is placed between the anode and cathode foils. This separator allows the electrolyte to penetrate while preventing direct electrical contact between the anode and cathode, which could lead to a short - circuit.

 

4. Assembly

The anode, cathode, and separator are then wound together in a spiral or stacked configuration, depending on the design of the capacitor. This assembly is placed into a capacitor case, which is usually made of aluminum or plastic. The case provides mechanical protection and helps to contain the electrolyte.

 

5. Impregnation

The assembled capacitor is then impregnated with the electrolyte. This is typically done under vacuum or pressure to ensure that the electrolyte fills all the pores in the separator and makes good contact with the anode and cathode foils. After impregnation, the capacitor is sealed to prevent the electrolyte from leaking out.

 

6. Aging and Testing

The newly - made capacitors are then aged. Aging involves applying a voltage to the capacitors for a certain period, which helps to stabilize their electrical properties. After aging, the capacitors undergo a series of tests, including capacitance measurement, leakage current testing, and breakdown voltage testing. Only capacitors that pass these tests are considered suitable for use.

 

Storage Conditions for Aluminum Electrolytic Capacitors

 

1. Temperature and Humidity

Aluminum electrolytic capacitors should be stored in an environment with a temperature range of +5°C to +35°C and a relative humidity of less than 75%. High temperatures can accelerate the evaporation of the electrolyte and cause the degradation of the capacitor's internal components. Humidity can also be a problem as it can lead to the corrosion of the aluminum foil and the deterioration of the capacitor's insulation.

 

2. Avoidance of Hazardous Substances

Capacitors should be kept away from environments containing water, saltwater, or oil. These substances can penetrate the capacitor and cause electrical short - circuits or corrosion. Additionally, they should be stored away from toxic gases such as hydrogen sulfide, sulfurous acid, nitrous acid, chlorine, and ammonia. These gases can react with the capacitor materials and damage their performance.

 

3. Protection from Radiation and Ozone

Exposure to ozone, ultraviolet rays, or radiation should be avoided. Ozone can oxidize the capacitor's insulating materials, while ultraviolet rays can cause the degradation of the plastic components. Radiation can also have a negative impact on the electrical properties of the capacitor.

 

4. Packaging and Shelf Life

It is advisable to keep the capacitors in their original packaging bags to protect them from dust, moisture, and other contaminants. Also, to ensure good solderability, the storage period of aluminum electrolytic capacitors should be controlled within 1 year. Over time, the capacitor's pins may oxidize, which can affect the soldering process.

 

Conclusion

The production of aluminum electrolytic capacitors is a complex and precise process that requires careful attention to detail at each stage. Similarly, proper storage conditions are essential to maintain the quality and performance of these capacitors. By following the production and storage guidelines outlined in this article, manufacturers and users can ensure the reliability and longevity of aluminum electrolytic capacitors in various applications.

UF Capacitors supplies a wide range of SMD Aluminum Electrolytic Capacitors (Chip Type): standard series #TCS, standard & wide temperature series #TCK, low impedance series #TLZ , extra low impedance series #TKZ and long life extra low impedance series #TFZ SMD electrolytic capacitors.

 

UF Capacitors TFS Series Chip Type,SMD Electrolytic Capacitors features with long life upto 5000hours, 

Low impedance, Low ESR and small size. This miniature size SMD electrolytic capacitors TFS series 

are perfect replacement of Panasonic FT series, following cross table FYI:

 

Photo	Description	UF Capacitors Series Code	Rubycon	Nichicon	Panasonic
	TCS 85C V-Chip Aluminum Electrolytic	TCS Series	SEV Series	UWX Series	EEE-X(A)S Series
	TCK 105C V-Chip Aluminum Electrolytic	TCK Series	SKV Series	UWT Series	EEEHA Series
	TFZ 105C 2000-5000 long life with extra ESR	TFZ Series	TZV Series TPV Series	UUD Series UUA Series NACZ Series UCD Series UWD Series	EEE-FK Series EEE-FT Series EEV-FK Series
	TLZ 105C 1000-2000h lower impedance	TLZ Series	SZV Series	UCL Series UCM Series	EEE-FC Series EEE-FT Series
	TMB Series 105C 2000h conductive polymer	TMB Series	PAV Series PHV Series	CV Series RFS Series	SVPC Series SVP Series