Vibration Step Stress
Specification Limits
1.5 grms
5 grms
Minimum Specified Operating Level (No loss of operation):
Operational Limits
Maximum Operating Level (No loss of operation):
Result Table
Level (grms
)
Problem
Root Cause
Corrective Action
Incorp.
-
5 grms, Y C13 broke.
axis
No RTV on C13.
Added RTV between C13 and
surrounding components.
7 grms, X C10, C40, C48 broke. No RTV on C40 or
Added generous amounts of RTV
C48; a little RTV on between C40, C48, C10 and their
axis
-
C10.
surrounding components.
7 grms, Y #4 lead of T2 broke. RTV only between
Added RTV between board and
board and T2 on one T2 on both ends of T2.
-
-
axis
end.
7 grms, Y L2 and part of T3 lead None.
None. Unit reached fundamental
limit of technology.
broken. Trace bared
beneath T3.
axis
Test Summary
Infrared Baseline Photo
Unit is allowed to stabilize at approximately 25°C ambient temperature, convection cooled, with
600 W output power before infrared photo is shot. See attached topside and bottomside photo.
Thermal Survey
After attaching thermocouples, unit is placed in the chamber, powered on, and allowed to reach a
stable temperature. Component temperature is monitored throughout the test. See attached chart for
all configurations.
Cold Start
Unit is placed in the chamber, power off, and allowed to stabilize at the ambient temperature.
With an oscilloscope probe attached to both the input and the output, power is applied and the
time difference between application of power and output voltage is recorded. See attached chart
for all configurations.
Vibration Qualification
One hour of random vibration in each of three (3) orthogonal axes. Profile: 0.038 g2/hz,
20-350 hz; -60 B/oct, 350-2000 hz; 4.86 grms.
HALT Temperature Cycling Step Stress and Vibration
Unit is exposed to progressively more severe operating temperatures and random vibration
environments. Failures that occur are diagnosed for root cause, corrective action is performed, and
then the test is continued. The levels are increased unti the test extremes or the fundamental limit
of the unit is reached (whether by technological or economic limitations.)
SLPOWER [ SL Power Electronics ]
