Preconditioning Process Flow: Sample Size/ optional

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Highly-Accelerated Temperature and Humidity Stress Test

HAST requires preconditioning  and is conducted with electrical bias at 130ºC and 85% RH for 96-100 hours.  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.  HAST is recommended for the qualification of any change that can potentially affect the corrosion resistance of the product. Thus, a new fab process, a new package, or a new fab/assembly site definitely requires HAST data. HAST is also recommended for changes in the die glassivation, metallization or thin film resistors, as well as changes in the molding compound.

Steady-State Temperature Humidity Bias Life Test (THB 85°C/85%RH)

Temperature, Humidity, Bias (THB) testing is a reliability test designed to accelerate metal corrosion, particularly that of the metallization on the die surface of the device.  Aside from temperature and humidity which are enough to promote corrosion of metals in the presence of contaminants, bias is applied to the device to provide the potential differences needed to trigger the corrosion process, as well as to drive  mobile contaminants to areas of concentration on the die. THB testing employs the following stress conditions: 1000 hours at 85 deg C, 85% RH, with bias applied to the device. The bias applied is usually designed to simulate the bias conditions of the device in its real-life application,  maximizing variations in the potential levels of the different metallization areas on the die as much as possible.   Surface-mount devices are also preconditioned prior to THB testing.

Temperature Cycling Test(TCT, Air to Air)

Temperature Cycle Testing (TCT) determines the ability of parts to resist extremely low and extremely high temperatures, as well as their ability to withstand cyclical exposures to these temperature extremes.Failure(fatigue failure) mechanisms accelerated by temperature cycling include die cracking, package cracking, neck/heel/wire breaks, and bond lifting. 

Power and Temperature Cycling(PTC)

This Power and Temperature Cycling Test is performed to determine the ability of a device to withstand alternate exposures at high and low temperature extremes with operating biases periodically applied and removed. It is intended to simulate worst-case conditions encountered in typical applications. This test method is considered destructive, and is intended primarily for device qualification.

Thermal Shock Test( Liquid to Liquid)

Thermal Shock is performed to determine the resistance of the part to sudden changes in temperature. The parts undergo a specified number of cycles, which start at ambient temperature. The parts are then exposed to an extremely low (or high) temperature and, within a short period of time, exposed to an extremely high (or low) temperature, before going back to ambient temperature. Failure mechanisms accelerated by thermal shock include die cracking, package cracking, neck/heel/wire breaks, and bond lifting

Autoclave(Pressure Pot)/Moisture Resistance

The autoclave Test, also known as a Pressure Cooker Test (PCT), or a Pressure Pot Test (PPOT), is a reliability test performed to assess the ability of a product to withstand severe temperature and humidity conditions.  It is used primarily to accelerate corrosion in the metal parts of the product, including the metallization areas on the surface of the die.  It also subjects the samples to the high vapor pressure generated inside the autoclave chamber. Autoclave testing consists of soaking the samples for 168 hours at 121ºC, 100% RH, and 29.7psia/205kPa.  This test is used to identify failure mechanisms internal to the package and is destructive.

Salt Atmosphere

The Salt Atmosphere test is conducted to determine the resistance of solid state device to corrosion and considered destructive. It is an accelerated test that simulates the effect of severe salt atmosphere exposure.

High Temperature Storage(HTS)

HTS test is performed to determine the effect on devices of long-term storage at elevated temperatures without any electrical stresses applied. HTS is effective for the reliability testing of samples in terms of mechanisms accelerated by temperature only, e.g., oxidation, bond and lead finish intermetallic growths, etc. Summary of industry-standard HTS conditions: 1000 hours @150ºC.