Very Good Soldering Quality of
the Metal Plates Configuration
Over and above the good
mechanical resistance, the metal plate configuration has
a further advantage, namely very good solderability and
solderjoint reliability in processing and application.
Regarding the thickness of
the layers, the electroplated end contacts of the SMD
ceramic capacitors are in the region of < 100mm and
spread very widely. The thickness of the layers of the
tested ceramic versions were measured at between 15mm and
70mm.
On the basis of the tests
carried out, it was established that, in practice, under
re-flow soldering conditions, the SMD film capacitors in
metal plate configuration which were examined, showed an
almost perfect solder quality.
The solderjoint / meniscus
of the ceramic versions tends to become a gritty /
crystallize surface. To obtain an acceptable soldering
quality, the processing temperature in all zones of the
reflow equipment had to be increased by 10°C. Even so,
the flow quality of the solder paste and the shiny
surface was nowhere near as good as in the processing of
the WIMA SMD in size code 1812. The following pictures
show printed circuit test boards which clearly
demonstrate this differing behavior. |
