prez rel test-7
Post on 07-Apr-2018
224 Views
Preview:
TRANSCRIPT
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 1/20
RELIABILITY AND DIAGNOSTIC
Faculty of Electronic Engineering and
Technologies
Anna Andonova
E-mail: ava@ecad.tu-sofia.bg
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 2/20
Definitions - determine the ability of Items to withstand
moderately severe shocks resulting from suddenly applied
forces or abrupt changes in motion encountered during
mishandling, improper transportation, or field operation
Shocks cause devices to degrade in performance, or to even
get damaged permanently
Repetitive shocks cause damage that is similar to thosecaused by extreme vibration
Testing requires shock pulses of 500 to 30,000 g (peak), with
the pulse width or duration ranging from 0.1 to 1 millisecond
RELIABILITY TESTS
Test Condition g Level (peak) Pulse Duration (ms)
A 500 1
B 1,500 0.5
C 3,000 0.3
D 5,000 0.3
E 10,000 0.2
F 20,000 0.2
G 30,000 0.12
Test Conditions for Mechanical ShockTesting per Mil-Std-883 Method 2002
The samples shall be subjected to
shock pulses in each of the followingorientations: X1, X2, Y2, Y1, Z1, Z2.
After test has been completed, external
visual inspection of the case, leads, and
seals shall be performed at 10 X to 20 X
Mechanical Shock Test
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 3/20
Definitions - to determine the resistance of the part to
sudden changes in temperature
The parts undergo a specified number of cycles
Start at ambient temperature then to an extremely low (or
high) temperature and, within a short period of time to an
extremely high (or low) temperature, before going back toambient temperature
Repetitive shocks cause damage that is similar to those
caused by extreme vibration
After the final cycle, external visual examination of the case,
leads, and seals shall be performed at 10 X to 20 X.
Electrical testing must also be performed to detect electrical
failures accelerated by the temp cycle
RELIABILITY TESTS
Thermal Shock
Chamber
Thermal Shock (TST)
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 4/20
Failure acceleration due to Thermal Shock and Temp
Cycling depends on the following factors:
the difference between the high and low temperatures used
the transfer time between the two temperatures
the dwell times at the extreme temperatures
Failure mechanisms accelerated by thermal shock include
die cracking
package cracking
neck/heel/wire breaks
bond lifting
RELIABILITY TESTSThermal Shock (TST)
Mil-Std-883 Method 1011 Specs : Thermal Shock Test
- Total Transfer Time < 10 seconds
- Total Dwell Time > 2 minutes
- Specified Temp reached in < 5 minutes
- Must be conducted for a minimum of 15 cycles
Condition Low Temp High Temp
A -40 (+0/-30) deg C 85 (+10/-0) deg C
B -0 (+2/-10) deg C 100 (+10,-2) deg C
C -55 (+0,-10) deg C 125 (+10,-0) deg C
D -65 (+0,-10) deg C 150 (+10,-0) deg C
For reliability testing or
qualification of new
devices, 1000 temp cycles
are usually performed
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 5/20
Definition - ability to resist extremely low
and extremely high temperatures, as well
as ability to withstand cyclical exposures
to these temperature extremes
(TST) closely resembles TCT and also
accelerates fatigue failures
subjecting the parts to the specified low
(or high) temperature then to the specified
high (or low) temperature for a specified
number of cycles
after the final cycle, external visualexamination and electrical testing to
device specifications shall be performed
RELIABILITY TESTSTemperature Cycle Testing (TCT)
Temperature Cycle Chambers
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 6/20
Failure mechanisms include
die cracking
package cracking
neck/heel/wire breaks
bond lifting.
For reliability testing or
qualification of new devices,
1000 temp cycles are usually
performed
RELIABILITY TESTSTemperature Cycle Testing (TCT)
Condition Low Temp High Temp
A -55 (+0/-10) deg C 85 (+10,-0) deg C
B -55 (+0/-10) deg C 125 (+15,-0) deg C
C -65 (+0/-10) deg C 150 (+15,-0) deg C
D -65 (+0/-10) deg C 200 (+15,-0) deg C
E -65 (+0/-10) deg C 300 (+15,-0) deg C
F -65 (+0/-10) deg C 175 (+15,-0) deg C
Mil-Std-883 Method 1010 Temp Cycle
Test Conditions
- Total Transfer Time <= 1 minute
- Total Dwell Time >= 10 minutes
- Specified Temp reached in <= 15
minutes
- Must be conducted for a minimum of 10
cycles
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 7/20
Definition - accelerate metal corrosion,particularly that of the metallizations
to provide the potential differences
needed to trigger the corrosion process,
as well as to drive mobile contaminants
to areas of concentration
stress conditions: 1000 hours at 85 deg
C, 85% RH, with bias applied to the device
intermediate readpoints at 48H, 96H,
168H, and 500H are often used
long duration, necessitating weeksbefore useable data are obtained
an alternative test, the HAST, has been
developed - more severe stress
conditions but shorter duration
RELIABILITY TESTSTemperature, Humidity, Bias (THB)
Temperature/Humidity
Chambers
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 8/20
Definition - a shorter alternative to (THB)
if THB testing takes 1000 H to complete, HAST
results are available within 96-100 H
requires preconditioning conducted with electrical
bias at 130 deg C and 85% RH for 96-100 H
electrical bias must be defined on:
power dissipation must be minimized to ensure that
moisture is always present at the surface
alternate pins must be subjected to opposite bias
(low voltage versus high voltage) as much as possible
potential differences between the various
metallizations on the die must be maximized
the operating voltage range for the device must also
be maximized, as long as the power dissipation is
kept under control
RELIABILITY TESTSHighly Accelerated
Temperature/Humidity Stress
Test (HAST)
HAST system
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 9/20
Definition - determine the reliability of devices under
operation at high temperature conditions over an
extended period of time
subjecting the parts to a specified bias or electrical
stressing, for a specified amount of time, and at a
specified high temperature (essentially just a long-term burn-in)
unlike production burn-in which accelerates early
life failures, HTOL testing is
applied to assess the potential operating lifetimes
(steady-state 'life test')
more concerned with acceleration of wear-out
failures
test duration may be decreased by increasing the
ambient temperature
RELIABILITY TESTSHigh Temperature
Operating Life (HTOL)
Burn-in Ovens
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 10/20
if not specified, an intermediateelectrical testing shall be performed
after 168 (+72,-0) H and after 504
(+168,-0) H
accomplished by utilizing any burn-
in oven capable of operating
continuously over long durations
failure mechanisms include
Time-Dependent Dielectric
Breakdown (TDDB)
electromigration
hot carrier effects
charge effects
mobile ionic contamination
RELIABILITY TESTSHigh Temperature
Operating Life (HTOL)
Mil Std 883 Method 1005 Specs :
- generally 1000 hours min. at 125 deg C
- max. rated Tc or Ta < 200 deg C (Class B)
- max. rated Tc or Ta < 175 deg C (Class S)
- Condition A : steady-state, reverse bias
- Condition B : steady-state, forward bias
- Condition C : steady-state, power/reverse bias
- Condition D : steady-state, parallel excitation
- Condition E : steady-state, ring oscillator
- Condition F : steady-state, temp.-accelerated
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 11/20
Definition - determine the reliability of devices under low temperature conditions over an extended period
of time
subjecting the parts to a specified bias or electrical
stressing, for a specified amount of time, and at a
specified low temperature
low temperature equivalent of the HTOL test
there are several requirements when powering up a
device
the device must not be overstressed nor should it
go to thermal runaway datasheet limits of the manufacturer must not be
exceeded
stressing must also be continuous, and should only
be interrupted at interim readpoints if required
RELIABILITY TESTSLow Temperature
Operating Life (LTOL)
LowTemperature
Burn-in Oven
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 12/20
biasing configuration may be
static
pulsed
even dynamic
ambient temperature shall not exceed the maximum limit of -10 deg C electrical testing must be performed within 96 hours after the bias to
the device has been removed
device is considered an LTOL failure if it fails to meet the applicable
procurement specification
test is usually performed to check for
hot carrier effects
commonly encountered failure mechanism accelerated by high
voltages and low temperatures
RELIABILITY TESTSLow Temperature
Operating Life (LTOL)
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 13/20
Definition - determine the effect on devices of long-term storage at elevated temperatures
without any electrical stresses applied
similar to Stabilization Bake (storing the parts
at the specified ambient temperature for a
specified amount of time) except that
HTS is done over a much longer period of time
(1000 H vs. 24 H for Stab Bake at 150 deg C)
purpose of HTS is to assess the long-term
reliability of devices under high temperature
conditions while that of Stabilization bake is
merely to serve as part of a screening sequenceor as a preconditioning treatment prior to the
conduct of other tests
RELIABILITY TESTSHigh-Temperature Storage (HTS)
Bake
Chamber/Oven
that
can be used for
High
Temperature
Storage
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 14/20
devices must be allowed toreach the specified
temperature before the
duration starts counting
end-point measurements
must be conducted within 96
H after the specified testconditions are removed
end-point measurements
include external visual
inspection and electrical
testing effective for the reliability
testing of samples in terms of
mechanisms accelerated by
temperature only
RELIABILITY TESTSHigh-Temperature Storage (HTS)
Summary of industry-standard HTS conditions: 1000
hours at 150 deg C.
Mil Std 883, Method 1008, Stabilization Bake Specs :
- storage at a high temperature for a specified duration
- Test Condition A : 75 deg C / 24 H minimum
- Test Condition B : 125 deg C / 24 H minimum
- Test Condition C : 150 deg C / 24 H minimum
- Test Condition D : 200 deg C / 24 H minimum
- Test Condition E : 250 deg C / 24 H minimum
- Test Condition F : 300 deg C / 24 H minimum
- Test Condition G : 350 deg C / 24 H minimum
- Test Condition H : 400 deg C / 24 H minimum
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 15/20
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 16/20
consists of three steps:
a bake to drive away all the moisture within the samples a temperature/humidity soak to drive controlled amounts of moisture into the
package
a form of thermal shock simulating the soldering process itself
accelerated failure mechanism
popcorn cracking
neck breaking and ball lifting
die cracking
moisture-related failure mechanisms may also arise but these should
generally not be considered as valid SHRT failures
baking is usually done for 24 hours at 125 deg C or 8 hours at 150 deg C
Soaking is usually done at 85 deg C/85% RH or 30 deg C/60%RH, for a
duration ranging from 24 hours to 192 hours
The shock is often done three times, and should be completed within 4 hours
after the soak
RELIABILITY TESTSSolder Heat Resistance Test (SHRT)
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 17/20
Definition - assess the ability of a product towithstand severe temperature and humidity
conditions
used primarily to accelerate corrosion in the
metal parts of the product
consists of soaking the samples for 168 hours at121 deg C, 100% RH, and 2 atm
intermediate readpoints at 48H and 96H may be
employed
Surface-mount samples are preconditioned prior
to autoclave testing PCT failures
arising from corrosion
moisture-related electrical leakage failures must
not be considered
RELIABILITY TESTSAutoclave Test, or Pressure Cooker Test
(PCT), or Pressure Pot Test (PPOT)
Autoclave
Chamber
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 18/20
Package Dimensions Test
Definition - examination to verify that the external physical dimensions of thedevice are in accordance with the applicable acquisition document
Constant Acceleration Test
Definition - determine the ability of parts to withstand high levels of constant
acceleration
used as
an indicator of the mechanical strength limits of a package
an in-line screen for parts with structural or mechanical weaknesses
The Mechanical Shock Test
Definition - determine the suitability of a device to be used in electronicequipment that will be subjected to moderately severe shocks from suddenly
applied forces or abrupt changes in motion
The Resistance to Solvents Test
Definition - determines the ability of a part to withstand exposure to solvents
RELIABILITY TESTSOther reliability tests
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 19/20
consists of immersing three (3) different groups of specimens in 3 different
solvent solutions for a minimum of 1 minute
solution composed of 80% kerosene/20% ethylbenzene
semi-aqueous based solvent (defluxer)
composed of 42 pbv DI water, 1 pbv monoethanolamine, and 1 pbv propylene
glycol monomethyl ether
after immersion, the specimen is brushed
immersion and brush cycle is conducted two more times for a total of three
cycles, after which the parts are rinsed and blow-dried
The Salt Atmosphere Test
Definition - accelerated laboratory corrosion test to simulate the effects of seacoast atmosphere on the device and package
consists of exposing the units to a salt fog, which is produced by atomizing a
salt solution
after the exposure, the units shall be washed with free-flowing D/I water for at
least 5 minutes
RELIABILITY TESTSOther reliability tests
8/6/2019 Prez REL Test-7
http://slidepdf.com/reader/full/prez-rel-test-7 20/20
The Vibration Test (Variable Frequency)
Definition - determine the ability of parts to withstand vibration of varying
frequency within a specified frequency range, and is considered to be
destructive
consists of subjecting the parts to a variable frequency vibration at specified
levels
achieved by simple harmonic motion having a peak-to-peak amplitude of
about 0.06 inch or a peak acceleration corresponding to the specified test
condition
the vibration frequency shall be varied approximately logarithmically between
20 to 2,000 Hz
The Vibration Test (Fatigue)
Definition - determine the ability of parts to withstand sustained vibration of
constant amplitude within a specified frequency range
consists of subjecting the parts to a constant amplitude simple harmonic
motion having a peak acceleration corresponding to the specified test condition
RELIABILITY TESTSOther reliability tests
top related