Datasheet

11© KEMET Electronics Corporation • P.O. Box 5928 • Greenville, SC 29606 • 864-963-6300 • www.kemet.com A4011_PEG124 • 1/10/2018
Axial Aluminum Electrolytic Capacitors – PEG124, +105°C and +125°C
Anode foil
Cathode foil
Tissues
Foil tab
Aging
Etching
Forming
Winding
Assembly
Filling (elyt)
Impregnation
Testing
Labeling
Packing
Sealing
Construction Data
The manufacturing process begins with the anode foil being
electrochemically etched to increase the surface area and
then “formed” to produce the aluminum oxide layer. Both the
anode and cathode foils are then interleaved with absorbent
paper and wound into a cylinder. During the winding process,
aluminum tabs are attached to each foil to provide the
electrical contact.
The winding is assembled to the capacitor Al-can and to
the Al-lid. The can is lled with electrolyte and the winding
is impregnated during a vacuum treatment. The capacitor
is sealed. Throughout the process, all materials inside the
housing must be maintained at the highest purity and be
compatible with the electrolyte.
Each capacitor is aged and tested before being packed. The
purpose of aging is to repair any damage in the oxide layer
and thus reduce the leakage current to a very low level. Aging
is carried out at elevated temperature and is accomplished by
applying voltage to the device while carefully controlling the
supply current. The process takes between 2 and 20 hours,
depending on voltage rating.
Damage to the oxide layer can occur due to a variety of
reasons:
• Slitting of the anode foil after forming
• Attaching the tabs to the anode foil
• Minor mechanical damage caused during winding
The following tests are applied for each individual capacitor.
Electrical:
• Leakage current
• Capacitance
• ESR
• Tan Delta
Mechanical/Visual:
• Pull strength test of wire terminals
• Print detail
• Box labels
• Packaging, including packed quantity