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P. Vianco and M. Neilsen
which solder joints are particularly weak. Secondly, stacked packages have relatively
large masses owing to the multiple molding compounds, dice, substrates, and solder
balls. The increased mass places higher stresses on the second-level interconnections
during shock and vibration events.
16.3.1.3 High-Reliability Electronics
The service temperature conditions for all but automotive under hood and energy
sector electronics have minimums and maximums of −40 and 85 °C, respectively
[24]. Automotive under hood conditions are more severe due to engine heat. The
temperature range is typically −40 to 125 °C. The harshest environments are those
experienced by down hole oil, gas, and geothermal well monitoring electronics where
maximum operating temperatures can reach 150–200 °C.
High-reliability electronics can be subjected to a wide range of vibration conditions. Automobile under hood electronics and, in particular, modules mounted
directly to the engine block or transmission case, experience significant vibration
loads [26]. Automotive applications, as well as space vehicles when undergoing
launch, experience significant vibration condition as validated by laboratory and
field test experiments. The resulting guidelines, together with finite element modeling
software, have allowed designers to predict vibration conditions down to the level of
the PWA and individual components.
Mechanical shock poses a particularly challenging environment for highreliability electronics. Several conditions and the corresponding shock loads generated by them, are shown below:
• Automotive: bumps in the road (10–40 Gs [27]);
• Military weapons: launch, penetrator warheads, (1000 to 100,000 Gs [23]);
• Space and satellite vehicles: launch and staging sequences (100–400 Gs [22]).
Finite element models have been developed to predict the shock loads experienced
by electronics assemblies down to the component level. The present challenge is to
develop the high loading rate, material properties, that are necessary to optimize the
fidelity of those computational model predictions.
16.3.1.4 Accelerated Aging
Printed wiring assemblies, which have stacked packages on them, are exposed to the
same accelerated aging regimens as used on other surface mount (and through-hole)
assemblies. Numerous consensus standards have been developed (e.g., Refs. [24, 27])
to specify the appropriate test parameters, test vehicles geometries, sample size, and
failure assessments with which to characterize the reliability of the interconnections.
It is necessary to also calculate the appropriate acceleration factor that correlates
the accelerated aging test results to the predicted behavior under the use conditions.
P. Vianco and M. Neilsen
which solder joints are particularly weak. Secondly, stacked packages have relatively
large masses owing to the multiple molding compounds, dice, substrates, and solder
balls. The increased mass places higher stresses on the second-level interconnections
during shock and vibration events.
16.3.1.3 High-Reliability Electronics
The service temperature conditions for all but automotive under hood and energy
sector electronics have minimums and maximums of −40 and 85 °C, respectively
[24]. Automotive under hood conditions are more severe due to engine heat. The
temperature range is typically −40 to 125 °C. The harshest environments are those
experienced by down hole oil, gas, and geothermal well monitoring electronics where
maximum operating temperatures can reach 150–200 °C.
High-reliability electronics can be subjected to a wide range of vibration conditions. Automobile under hood electronics and, in particular, modules mounted
directly to the engine block or transmission case, experience significant vibration
loads [26]. Automotive applications, as well as space vehicles when undergoing
launch, experience significant vibration condition as validated by laboratory and
field test experiments. The resulting guidelines, together with finite element modeling
software, have allowed designers to predict vibration conditions down to the level of
the PWA and individual components.
Mechanical shock poses a particularly challenging environment for highreliability electronics. Several conditions and the corresponding shock loads generated by them, are shown below:
• Automotive: bumps in the road (10–40 Gs [27]);
• Military weapons: launch, penetrator warheads, (1000 to 100,000 Gs [23]);
• Space and satellite vehicles: launch and staging sequences (100–400 Gs [22]).
Finite element models have been developed to predict the shock loads experienced
by electronics assemblies down to the component level. The present challenge is to
develop the high loading rate, material properties, that are necessary to optimize the
fidelity of those computational model predictions.
16.3.1.4 Accelerated Aging
Printed wiring assemblies, which have stacked packages on them, are exposed to the
same accelerated aging regimens as used on other surface mount (and through-hole)
assemblies. Numerous consensus standards have been developed (e.g., Refs. [24, 27])
to specify the appropriate test parameters, test vehicles geometries, sample size, and
failure assessments with which to characterize the reliability of the interconnections.
It is necessary to also calculate the appropriate acceleration factor that correlates
the accelerated aging test results to the predicted behavior under the use conditions.