IGBT Modules - Technologies, Driver and Application (Second Edition) - page 102

Fig. 2.28
Coldwelding of PCBandmodulewith press-inpins
Press-in technology can, in principle, be used with any standard PCB. The differences
are in the detail. Tolerances provided by PCB manufacturers can be compensated for
by the press-in pins, but different manufacturing processes affect the current handling
capacity of the contact zone. In the well-known chemical tin and HAL
differences can be expected in the load contact capability. The layer of tin is not
homogenous in the HAL/HASL process. In each case, the lenticular arches that are
formed reduce the bonding surface between the press-in contact and the through-hole
of the PCB. This eventually affects the current carrying capacity at that point.
Furthermore, the tolerances of the layer thicknesses of the tin in the chemical tin
process aremuch lower than those in theHAL/HASL process.
One advantage of press-in technology over soldering is that it makes it very easy to
disassemble the PCB. Using an appropriate tool, the PCB can be separated from the
IGBTmodule in just a few seconds.While the PCB can then be re-used for pressing in,
the module is not re-useable, because the pins are deformed by the first pressing.
However, thesemodules canbe re-bonded toaPCB by solderin
HAL/HASL: Hot Air (Solder) Leveling is aphysical process that coats PCBwitha layer of tin.
Press-in pins are generally suited to connection via soldering, so these pin variants ultimately offer users two
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