PAGE 14 • ITW Paktron • P.O. Box 4539, 1205 McConville Road, Lynchburg, Virginia 24502 • Tel 434-239-6941 • Fax 434-239-4730 • www.paktron.com
Type CS4/CS6/CB4 Capstick®Capacitor
Metallized Polyester (PET) Dielectric
Miniaturized pass filters made possible by
high frequency switching technology need
tiny but low ESR and ESL capacitors to
attenuate ripple and reflected RFI over wide
frequency bands. With equivalent series
resistance approaching zero, non-polar MLP
Capacitors reliably sink high ripple currents
in high density converters, run cool and are
stable.
The trend toward distributed power man-
agement
and modular power converters has
driven the development of high efficiency,
low profile power train components. The con-
ventional capacitors historically used in rip-
ple filtering applications are
either too large
or not suitable for popular methods
of surface
mounting. Electrolytic capacitors, while size
efficient, do not provide the desired, stable
electrical characteristics and reliability. Large
value multilayer ceramic capacitors are noto-
riously fragile, expensive and unstable over
voltage and temperature extremes. A novel
but proven capacitor technology, built upon
selected manufacturing techniques of multi-
layer ceramic and stacked, plastic film
capacitors is now the preferred choice. Now
film capacitor reliability can be found in chip
and block shaped MLP capacitors that
approach the board space sizes of X7R,
MLC (Ceramic) types. These unique multilay-
er polymer capacitors (MLP's) offer excellent
electrical stability under AC and DC current
loads and are not subject to the cracking,
shorting or TC mismatch inherent in Ceramic
(MLC) capacitor products. They are suitable
as input
and output filter capacitors in mega-
hertz frequency
switching converters, high
power ballasts and inverter drives at ambient
temperatures from -55° C to 125° C.
ULTRA LOW IMPEDANCE CONSTRUCTION
Figure 1 illustrates the multiple stacking
technique used to make the MLP structures
and the cross section which highlights simi-
larities to stacked film and MLC construction.
An all aluminum electrode and termination
construction results in a low resistance and
high current connection. The terminations are
gathered to multiple pin lead frames for low-
est ESR and ESL current handling. Low
loss
and frequency stable, ultra thin polyethy
lene-
terephthalate polymer film is used as the
dielectric.
DRIVEN BY HIGH FREQUENCY POWER
CONVERSION APPLICATIONS
The trend in power conversion is the
increase in switching frequency to minimize
the size of the magnetic and filter components
and boost the wattage per unit volume. Driven
by portable computers and the distributed
power approaches of both telecom and com-
puter systems, switching
frequencies have
risen from 20 kilohertz to between 400 KHz
and 1 megahertz in high density
power con-
verters. The filter capacitors have become an
important issue as low impedance and equiv-
alent series resistance are needed for reliable
high frequency current handling. The MLP
Capstick Capacitor can increase the series
current of the converter which translates into
higher wattage density at maximum efficiency.
NOTES ON USABILITY AND RELIABILITY
Because of the use of the well known PET
dielectric in ultra thin sheet, the reliability of
these
capacitors is far better than the industry
experience
with electrolytic or ceramic capac-
itors. There exists no capacitance drop or
aging with time. The dissipation factor is sta-
ble over time. The insulation resistance tends
to get better under the influence of heat and
voltage. We have shown that in-circuit prob-
lems are evident immediately
and usually the
result of mishandling or overheating
during
mounting assembly. There exist no metal
leaching or dielectric diffusion mechanisms to
affect the reliability over time. A complete reli-
ability
data package on this and other quality
MLP capacitor styles may be obtained by
contacting ITW Paktron.
MOUNTING OPTIONS
The Capstick can be conditioned for sur-
face mounting (including IR Reflow). Leads
can be trimmed to a dimension for butt or
through-hole mounting, or configured as gull
wing leads. See Appendix for Capstick
soldering guidelines.
LOW ESR, MULTILAYER POLYMER (MLP) CAPACITORS
Figure 1
Capstick Mounting Pad Layout
Capstick Mounting Pad Layout
Right
Part Number
Number of Leads
per Side A
Note: All left side capacitor leads are
joined in common internal to the
capacitor and all right side
capacitor leads are also joined in
or.
”565.04G6SC005K474
105K500CS6G
334K400CS6G
8
3
0.565”
0.565”
474K400CS6G 3 0.565”
105K400CS6G 7 0.565”
205K100CS4G, 205K100CB4G 3 0.365”
405K100CS4G, 405K100CB4G 3 0.365”
475K100CS4G, 475K100CB4G 3 0.365”
685K100CS4G 50.365”
106K100CS4G, 106K100CB4G 7 0.365”
106K050CS4G 5 0.365”
206K050CS4G 9 0.365”
CS/CB Surface Mount Pad Layout
Typical Recommendations
Left Right
0.110”
0.040”
A0.110”
0.100”