MJE18204 Datasheet, PDF (10/12 Pages) Motorola, Inc – POWER TRANSISTORS 5 AMPERES 1200 VOLTS 35 and 75 WATTS

MJE18204 MJF18204
TEST CONDITIONS FOR ISOLATION TESTS*
MOUNTED
CLIP ^{FULLY ISOLATED}
PACKAGE
LEADS
MOUNTED
CLIP
FULLY ISOLATED
PACKAGE
0.107″ MIN
LEADS
MOUNTED
FULLY ISOLATED
PACKAGE
0.107″ MIN
LEADS
HEATSINK
0.110″ MIN
HEATSINK
Figure 24. Screw or Clip Mounting
Position for Isolation Test Number 1
Figure 25. Clip Mounting Position
for Isolation Test Number 2
* Measurement made between leads and heatsink with all leads shorted together
HEATSINK
Figure 26. Screw Mounting Position
for Isolation Test Number 3
MOUNTING INFORMATION**
4–40 SCREW
CLIP
PLAIN WASHER
HEATSINK
COMPRESSION WASHER
NUT
HEATSINK
Figure 27a. Screw–Mounted
Figure 27b. Clip–Mounted
Figure 27. Typical Mounting Techniques
for Isolated Package
Laboratory tests on a limited number of samples indicate, when using the screw and compression washer mounting technique, a screw
torque of 6 to 8 in ^. lbs is sufficient to provide maximum power dissipation capability. The compression washer helps to maintain a
constant pressure on the package over time and during large temperature excursions.
Destructive laboratory tests show that using a hex head 4–40 screw, without washers, and applying a torque in excess of 20 in ^. lbs will
cause the plastic to crack around the mounting hole, resulting in a loss of isolation capability.
Additional tests on slotted 4–40 screws indicate that the screw slot fails between 15 to 20 in ^. lbs without adversely affecting the pack-
age. However, in order to positively ensure the package integrity of the fully isolated device, Motorola does not recommend exceeding 10
in ^. lbs of mounting torque under any mounting conditions.
** For more information about mounting power semiconductors see Application Note AN1040.
10
Motorola Bipolar Power Transistor Device Data