G-3
Various dielectrics used have been paper, paper-polyester,
polyester, polycarbonate, polysulfone, polystyrene,
polypropylene, TFE fluorocarbon, polyvinylidene fluoride,
and others. Capacitors hav e been produced using the discrete
foil and metalized electrode systems. Impregnants employed
include mineral oil, wax,Vitamin Q® silicone oil and various
so-called solid impregnants.
Capacitor housings include drawn and fabricated metal
shells in standard, rectangular, and special shapes, glass and
ceramic tubes, cast epoxy housings, molded housings,
plastic-film tubes, plastic-film wraps, and epoxy and resin
coatings. Where required, special mounting studs and brack-
ets have been furnished.
Capacitance tolerances to meet specific application needs
are available within the limits of the capacitor construction.
Units with matched capacitor sections, multiple sections of
different dielectrics, pulse forming networks, capacitor net-
works, capacitor standards, or other application specific
capacitors, are available to meet your circuit needs.
Special paper and film-type capacitors ha v e been pro vided
with capacitance ratings from 0.0001µF to 2000µF and with
voltage ratings from 30 VDC to 30,000 VDC. Capacitors
have been supplied to operate over the temperature range of
-65°C to +200°C.
The rigid quality control exercised by Dearborn
Electronics Inc. on all its standard production is also applied
to custom-fabricated capacitors. Where necessary, special
testing is done to verify requirements, such as low dielectric
absorption, ultra-high insulation resistance, low dissipation
factor, stability under temperature cycling or under specified
environmental conditions, etc.
If you have need for special capacitor designs utilizing
paper or film dielectrics, Dearborn will be glad to make
recommendations on how best to meet your application
needs.
Dearborn evaluates new dielectrics as they become avail-
able and has been a leader in the introduction of new film
capacitor types.
There are some specialty dielectrics available today which
offer significant improvement in electrical or physical char-
acteristics. They are as follows:
Polyvinylidene Floride (PVDF)
Polyethylene Naphthalate (PEN)
Fluorene Polyester (FPE)
PVDF has a dielectric constant of 10 as compared with a
dielectric constant of approximately 3 for other commonly
used dielectrics. This higher dielectric constant and accept-
able dielectric strength results in a relative energy density
almost 2 times that of other dielectric systems. This film has
been successfully used in portable medical equipment and
spacecraft applications where improved energy density is of
paramount importance.
PEN has better high temperature resistance, higher
mechanical strength, and improved dimensional and chemi-
cal stability when compared to polyethylene terephthalate
(PET). As a result it is possible to produce PEN in
thicknesses below 1.0µm while retaining good handling
characteristics. The use of these sub-micron thicknesses
gives PEN a significant advantage where high capacitance
density is required at relatively low voltages.
FPE has an operating temperature of up to 300°C and is
one of the films that is part of the continuous research of
very high temperature films Dearborn participates in.
HIGH PERFORMANCE FILMS
CUSTOM DESIGN