MJE18004G Datasheet, PDF (9/11 Pages) ON Semiconductor – NPN Bipolar Power Transistor For Switching Power Supply Applications

MJE18004G, MJF18004G
TEST CONDITIONS FOR ISOLATION TESTS*
MOUNTED
FULLY ISOLATED
CLIP
PACKAGE
LEADS
MOUNTED
FULLY ISOLATED
CLIP
PACKAGE
0.099″ MIN
LEADS
MOUNTED
FULLY ISOLATED
PACKAGE
0.099″ MIN
LEADS
HEATSINK
0.110″ MIN
Figure 22a. Screw or Clip Mounting
Position for Isolation Test Number 1
HEATSINK
Figure 22b. Clip Mounting Position
for Isolation Test Number 2
*Measurement made between leads and heatsink with all leads shorted together
HEATSINK
Figure 22c. Screw Mounting Position
for Isolation Test Number 3
MOUNTING INFORMATION**
4-40 SCREW
CLIP
PLAIN WASHER
HEATSINK
COMPRESSION WASHER
NUT
HEATSINK
Figure 23a. Screw−Mounted
Figure 23b. Clip−Mounted
Figure 23. 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
package. However, in order to positively ensure the package integrity of the fully isolated device, ON Semiconductor does not recom-
mend exceeding 10 in ^. lbs of mounting torque under any mounting conditions.
** For more information about mounting power semiconductors see Application Note AN1040.
http://onsemi.com
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