EPCOS Product Brief 2016
Film Capacitors
TM
PCC Power Capacitors for HybridPACK IGBT Modules
www.epcos.com V1.1 - Edition March 2016 Technology
Film assembly Self-healing property
1) Metal-end spray layer 4) Heavy-edge 1) Organic dielectric 7) Boundary layer between
2) Free margin 5) Dielectric 2) Metalized electrodes plasma zone and
3) Metallization, flat or CSP 3) Material displacing shock wave dielectric
(with or without structure) 4) Air gap 8) Break down channel
5, 6) Plasma discharge zone 9) Dielectric in gas zone
10) Isolation area
Fig. 1: Cross section of a metalized film capacitor Fig. 2: Self-healing property of a metalized film capacitor
Metallized film capacitors (fig.1) named segmented or Typical rated voltages (V):
have the advantage that for structured metalized film
IGBT PCC capacitor
certain failures in the dielectric the capacitors. See fig. 3 example of
rated
capacitor will not go into short a T-segmentation:
Rated Maximum
voltage
thanks to the ultrathin metallized
1)
voltage voltage
electrode (thickness typical 10 to
100 nm) and the use of aluminium
650 - 705 450 500
as material for the electrodes. If a
breakdown occurs, the aluminium
750 500 550
will evaporate around the break-
1200 900 950
down spot and immediately
oxidize to Al O , which is an
1) For limited time, please refer to data sheet
2 3
excellent insulator. So the
breakdown spot becomes high-
The rated voltage is defined as the
impedance and is insulated from
continuous operating voltage tak-
the rest of the capacitor. The
ing into account for the calculation
insulated area is formed in a few
of the expected lifetime.
microseconds and ensures the full
The maximum voltage is the
functionality of the capacitor after EPCOS possesses different
maximum operating voltage to be
breakdown. winding technologies:
applied on the capacitor for short
This behaviour is called clearing The stacked technology, operations (e.g. up to 10% of the
or self-healing (fig. 2). In prin- typically used for PCC film expected calculated lifetime).
ciple there should not be any capacitors, for which the film is
A detailed lifetime calculation
further clearing during the service already wound flat on the
based on a mission profile (voltage,
life, since all capacitors are winding machine. This tech-
temperature) can be submitted
typically cleared with a voltage nology offers the highest fill
upon request.
of 1.5 times the rated voltage factor and the lowest ESR.
during the production process.
The flat pressed winding tech-
nology which is most commonly
Additionally, to limit the energy
used on the market for this type
dissipation during a clearing event,
of application today. This tech-
for some designs at least one
nology offers the lowest costs at
electrode is divided into segments,
a good performance.
connected by small links or fuses.
The capacitors are typically
EPCOS AG 2016 2