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BUT11AF Datasheet, PDF (4/8 Pages) Motorola, Inc – POWER TRANSISTOR 5.0 AMPERES 450 VOLTS 40 WATTS | |||
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BUT11AF
TEST CONDITIONS FOR ISOLATION TESTS*
MOUNTED
CLIP FULLY ISOLATED
PACKAGE
LEADS
MOUNTED
CLIP
FULLY ISOLATED
PACKAGE
0.107â³ MIN
LEADS
MOUNTED
FULLY ISOLATED
PACKAGE
0.107â³ MIN
LEADS
HEATSINK
0.110â³ MIN
HEATSINK
Figure 7. Screw or Clip Mounting Position
for Isolation Test Number 1
Figure 8. Clip Mounting Position
for Isolation Test Number 2
*Measurement made between leads and heatsink with all leads shorted together.
HEATSINK
Figure 9. Screw Mounting Position
for Isolation Test Number 3
MOUNTING INFORMATION
4-40 SCREW
CLIP
PLAIN WASHER
HEATSINK
COMPRESSION WASHER
NUT
HEATSINK
Figure 10. 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 4â40 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 4â40 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 recommend exceeding
10 in . lbs of mounting torque under any mounting conditions.
http://onsemi.com
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