01 March 2005
8-5.2. ESD RELATED FAILURE MECHANISMS. ESD
related failures typically include the following:
Typical Static Charge
PC Board Rubbed With:
a. Thermal secondary breakdown.
b. Metallization melt.
c. Dielectric breakdown.
d. Gaseous arc discharge.
8-4.2. CATASTROPHIC FAILURES. These are
failures that result from direct contact between an IC
e. Surface breakdown.
and a high voltage static charge, sufficient to cause
breakdown in the device.
f. Bulk breakdown.
8-4.2.1. Direct Failures. While upset failures occur
g. Chip memory losses.
when the equipment is operating, catastrophic failures
can be the results of electrical overstress of electronic
8-5.3. V O L T A G E AND POWER DEPENDENT
parts caused by ESD. For example, discharge from a
FAILURE MODES. Thermal secondary breakdown,
person or object, an electrostatic field, or high voltage
metallization melt, and bulk breakdown are power-
spark discharge. Some catastrophic failures may not
dependent failure mechanisms. Dielectric breakdown,
occur until some time after exposure to an ESD. Such
gaseous arc discharge, and surface breakdown are
is the case with marginally damaged ESD parts, which
voltage-dependent failure modes. Refer to MIL-HDBK-
require operating stress and time to cause further
773, MIL-HDBK-263 and MIL-STD-1686 for more
damage and complete failure. Only certain parts seem
detailed descriptions of these microelectronic/
to be susceptible to this latest failure process. There
semiconductor device failure mechanisms.
are some types of catastrophic failures that could be
mistaken for upset failures. For example, ESD could
8-6. IDENTIFICATION OF ESD MATERIALS.
result in aluminum short circuiting the SiO2 dielectric
layer of an IC. Subsequent high currents flowing through
this circuit path could vaporize the aluminum and block
For further assistance in identifying ESD
devices, avionic technicians should refer to
8-4.2.2. Latent Failures. These are failures that occur
M I L - H D B K - 7 7 3 , MIL-HDBK-263, and
by damage of the device over time and usually reduce
operating life. This suggests that an IC can be subjected
to repeated exposure to static charges that are
8-6.1. GENERAL. The electronic industry has only
cumulative in effect. Latent failure may be confused
recently become aware of the cost and hazards of ESD
with upset failure if it occurs during equipment operation.
Materials that have been in the military supply system
for several years may not be identified as ESD sensitive.
Avionic technicians should treat any device as ESD if
there is any doubt as to its classification. For example,
8-5.1. GENERAL. Regardless of the type of failure,
a piece of avionic equipment may use a small relay that
the device itself is either power sensitive or voltage
has a driver or diodes encased within it. These packages
sensitive. Voltage sensitive parts fail due to dielectric
are probably ESD sensitive devices, yet relays are not
breakdown of insulating layers. Other parts are power
usually considered ESD.
sensitive, where pulse, shape, duration, and energy
can produce power levels resulting in thermal
8-6.2. SUPPLY SYSTEM PRACTICES. The military
breakdown. For example, hybrid ICs are voltage
supply system currently marks packages containing
sensitive in the form of thick film resistors. Likewise,
piezoelectric crystals are voltage sensitive. Some
However, these markings are subject to change as the
monolithic ICs are power sensitive.
ESD program established by each parent service
organization becomes more sophisticated. Therefore,