HAST (Highly Accelerated Temperature and Humidity
Stress Test)
Procedure: JESD22-A110-B / JESD22-A118
Purpose: The highly accelerated temperature and humidity
stress test is performed for the purpose of evaluating the reliability
of non-hermetic packaged solid-state device in an environment with high
humidity. It employs severe condition of temperature, humidity, and
bias, which accelerate the penetration of moisture through the external
protective material (encapsulated or seal) or along the interface between
the external protective material and the metallic conductor, which pass
through it. Samples of surface mount devices are subjected to preconditioning
and a final electrical test prior to the highly accelerated temperature
and humidity stress test.
Thermal Shock (Liquid to Liquid)
Procedure: MIL-STD-883 Method 1011.9 / JESD22-A106-A
Purpose: Thermal shock testing is similar to temperature
cycle testing, except that in thermal shock tests an additional stress
is provided: a sudden change in temperature due to a rapid transfer
time. Thus the test can detect failure mechanisms caused by temperature
transients and temperature gradients. The cycling test system has one
fluorocarbon bath at -65 or –55 °C (LCD driver) and the other
fluorocarbon bath at 150 or 125 °C. During thermal shock testing,
devices are inserted into the cycling test system and held at cold dwell
for 5 minutes and then heated to hot dwell for 5 minutes. One cycle
includes the duration at both extreme temperatures and the two transition
times. The transition period is less than 10 seconds at 25 °C. The
test duration is 100 cycles. Samples of surface mount devices must undergo
preconditioning and pass a final electrical test prior to the thermal
shock test.
Autoclave or Pressure Cooker Test
Procedure: JESD22-A102-C / EIAJ-IC-121-18
Purpose: The pressure cooker test is an environmental
test that measures device resistance to moisture penetration and the
effect of galvanic corrosion. Samples of surface mount devices are subjected
to preconditioning and a final electrical test prior to the pressure
cooker test. After the pressure cooker test, the leads of the test samples
are cleaned and then baked at 150 °C for 1 hour before the final
electrical test.
Temperature Cycling (TC) Air to Air
Procedure: JESD22-A104-B /Mil-Std-883 Method 1010.7
Purpose: Temperature cycle testing is to study the
effect of thermal expansion mismatch among the different components
within a specific die and packaging system. The cycling test system
has a cold dwell at - 65 or –55°C and a hot dwell at 150 or
125 °C. It employs a circulating air environment to ensure rapid
stabilization at a specified temperature. During temperature cycle testing,
devices are inserted into the cycling test system and held at cold dwell
for 15 minutes, and then the devices are heated to hot dwell for 15
minutes. One cycle includes the duration at both extreme temperatures
and the two transition times. The transition period is less than one
minute at 25°C. Samples of surface mount devices must first undergo
preconditioning and pass a final electrical test prior to the temperature
cycle test.
Temperature Humidity Bias Lifetest 85oC/85%
Procedure: JESD22-A101-B
Purpose: The purpose is to evaluate the reliability
of non-hermetic solid state devices
in a humid environment.
Temperature-Humidity-Bias Test (THB)
Procedure: (EIAJ-IC-121-17)
Purpose: The temperature-humidity-bias test is an environmental
test designed to measure the corrosion and moisture resistance of plastic-encapsulated
circuits. A nominal reverse bias is applied to the device to create
electrolytic cells necessary to accelerate corrosion of the metallization
or bond pads without heating the device. The duration of the test is
1000 hours, with readouts (final electrical tests) at 168 hours and
500 hours during the test. The stress temperature is 85 °C, and
the humidity is RH 85%. The bias is the maximum operating voltage. Samples
of surface mount devices must undergo preconditioning and pass a final
electrical test prior the THB test
HTOL (High Temperature Operating Lifetest)
Procedure: JESD22-A108-B
Purpose: High temperature operating life (HTOL) test
is to determine the reliability of products by accelerating thermally
activated failure mechanisms by subjecting samples to extreme temperatures
under biased operating conditions. The test is used to predict long
term failure rates. All test samples are screened directly after final
electrical testing. The oven temperature for the HTOL test is 125 °C.
Testing is performed with dynamic signals applied to the device. The
typical Vcc is the maximum operating voltage.
High-Temperature Storage Life Test (HTSL)
Procedure: MIL-STD-883 Method 1008 / JESD22-A103-B
Purpose: The high-temperature storage life test measures
device resistance to a high-temperature environment that simulates a
storage environment. The stress temperature is set to 150°C or 125°C
to accelerate the effect of temperature on the test samples. In the
test, no voltage bias is applied to the devices.
Bias Life Test (BLT)
Procedure: MIL-STD-883 Method 1005.8 / EIAJ-ED4701-D323
Purpose: Bias life test is to detect possible defects
on passivation (contamination, surface inversion, un-stable characteristics
of film), PN junction (junction degradation), oxide film (mobile ions,
interface states), and bonding (open moralization, bonding defect).
The test temperature is 125 °C and the duration is 1000 hours. The
pins of the devices are combination biased.
Preconditioning
Procedure: JESD22-A113-B
Purpose: Preconditioning is to measure the resistance
of surface mount devices to the storage environment at the customer
site and to thermal stress created by IR reflow. Before they undergo
the temperature humidity bias test, the temperature cycle test, the
thermal shock test, the pressure cooker test or the highly-accelerated
temperature and humidity stress test, surface mount devices are subjected
to preconditioning and must then pass a final electrical test
Real Time Thermal Profiling
Procedure: IPC/JEDEC J-STD-020B / JESD22-A113-B
Purpose: To insure that the reflow profile requirements
for each specific package is met during the reflow process for preconditioning.
Thermal profiling also verifies the specified ramp/soak times and temperature
are met for temperature cycle and thermal shock.
Solderability
Procedure: JESP22-B102 / Mil-Std-883 Method 2003.7
Purpose: To evaluate the solderability of terminations
that are normally joined by a soldering operation. The evaluation is
made on the basis of the ability of the terminations to be wetted by
a coating of solder, and to produce a suitable fillet when dipped in
solder. An accelerated aging test is required that simulates natural
aging under a combination of various storage conditions that have different
deleterious effects.
Fine and Gross Leak Testing (Seal)
Procedure: Mil- Std-883E Method 1014.9
Purpose: To determine the effectiveness (hermeticity)
of the seal of microelectronic, semiconductor, and related devices with
designed internal cavities.
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