Temperature Operating Life (LTOL) Test
Low Temperature Operating Life (LTOL) test is a test
performed to determine the reliability of devices under
conditions over an
period of time. It
consists of subjecting the parts to a specified
bias or electrical
stressing, for a specified
amount of time, and at a specified low temperature.
The LTOL test is basically just the low temperature equivalent of the HTOL
test. In fact, both tests are documented by JEDEC in a single
standards spec, JEDEC
are several requirements when powering up a device during LTOL. As
in HTOL, the device must not be overstressed nor should it go to thermal
runaway. The datasheet limits of the manufacturer must not be exceeded.
The stressing must also be
continuous, and should only be interrupted at
interim readpoints if required. The biasing configuration may be
static, pulsed, or even dynamic.
otherwise specified, the ambient temperature for LTOL test shall not
exceed the maximum limit of
-10 deg C.
Example of a
Low Temperature Burn-in Oven
in HTOL, electrical testing must be performed within
96 hours after the
bias to the device has been removed. A device is considered an LTOL failure if it fails to meet the applicable procurement
LTOL test is usually performed to check for
hot carrier effects,
a commonly encountered failure mechanism accelerated by high voltages
and low temperatures.
Test or PCT; Temperature
Heat Resistance Test (SHRT);
Reliability Modeling; Qualification
Package Failures; Die
All Rights Reserved.