CLP200M Datasheet, PDF (18/21 Pages) STMicroelectronics – OVERVOLTAGE AND OVERCURRENT PROTECTION FOR TELECOM LINE

CLP200M
SUBSTRATES AND MOUNTING INFORMATION
The use of epoxy FR4 boards is quite common for
surface mounting techniques, however, their poor
thermal conduction compromises the otherwise
outstandingthermal performanceof the PowerSO-
10. Some methods to overcome this limitation are
discussed below.
One possibility to improve the thermal conduction
is the use of large heat spreader areas at the cop-
per layer of the PC board. This leads to a reduction
of thermal resistance to 35 °C for 6 cm² of the
board heatsink (see fig. 2).
Use of copper-filled through holes on conventional
FR4 techniques will increase the metallization and
decrease thermal resistance accordingly. Using
a configurationwith 16 holes under the spreader of
the package with a pitch of 1.8 mm and a diameter
of 0.7 mm, the thermal resistance (junction -
heatsink) can be reduced to 12°C/W (see fig. 3).
Beside the thermal advantage, this solution allows
multi-layer boards to be used. However, a draw-
back of this traditional material prevent its use in
very high power, high current circuits. For instance,
it is not advisable to surface mount devices with
currents greater than 10 A on FR4 boards. A
Power Mosfet or Schottky diode in a surface mount
power package can handle up to around 50 A if
better substrates are used.
Fig 2 : Mounting on epoxy FR4 head dissipation by extending the area of the copper layer
Copper foil
FR4 board
Fig 3 : Mounting on epoxy FR4 by using copper-filled through holes for heat transfer
Copper foil
FR4 board
heatsink
heat transfer
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