IC and Product Testing

Reliateck offers a dedicated Test laboratory that specializes in IC and Product Testing. Because devices and products evolve in complexity and designs change frequently, IC and product testing is necessary to ensure design compliance and reduce defects, thereby increasing end product yield.

IC and MES samples used to demonstrate component integrity are randomly selected from end-of-line inventories and are representative of their respective product family to insure proper coverage; i.e., package family, die family, and assembly location. The procedures and test methods used by Reliateck are those commonly used by integrated circuit manufacturers. The standards referenced by Reliateck are JEDEC-22 for plastic encapsulated components and MIL-STD-883 where applicable.

Dynamic High Temperature Operating Life (DHTOL)

Dynamic High Temperature Operating Life testing is used to accelerate thermally activated failure mechanisms in IC components by the application of high temperatures and the use of dynamic bias conditions. The temperature and applied voltage vary with the product being stressed, with the typical ambient temperature equal to +125°C and the applied bias equal to or greater than the maximum datasheet value. The test results from DHTOL are used in reliability modeling to estimate the long term failure rate of components.  

Highly Accelerated Stress Test (HAST) 

HAST is used in order to evaluate the reliability of non-hermetic IC components in humid environments.  It employs severe conditions of temperature, pressure, humidity, and bias, which accelerate the penetration of moisture through the package material, or along the interface between the package material and the metallic conductors passing through it.  This test is considered an accelerated form of Temperature Humidity.

Temperature, Humidity Bias Test (THB)

Temperature, Humidity, Bias 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.

Surface-mount devices are also preconditioned prior to THB testing. During THB proper, intermediate read-points at 48H, 96H, 168H, 500H and 100H are often used.  This gives look-ahead reliability data as the THB test progresses.       

Temperature Cycling (TC)

Temperature Cycling TMCL is used to determine the resistance of ICs to fast, alternating exposure to extremely high and low temperatures. Physical damage and permanent changes in electrical characteristics are caused by the mechanical stresses at interfaces, which are generated by thermal expansion and contraction. Effects of TMCL include cracking and delaminating of packages, thin films on the silicon substrate and the silicon itself, and changes in electrical characteristics caused by the mechanical damage.  TC is applicable for screening, qualification, and reliability monitoring. It is generally considered destructive if components are subjected to more than 10 cycles.

Thermal Shock

Thermal Shock test is performed to determine the resistance of the part to sudden and rapid 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.

 After the final cycle, external visual examination of the case, leads, and seals shall be performed at 10 X to 20 X. The marking shall also be inspected at no greater than 3 X.  An illegible mark and/or any evidence of damage to the case, leads, or seals after the stress test shall be considered a failure.  
Failure mechanisms accelerated by thermal shock include die cracking, package cracking, neck/heel/wire breaks and bond lifting.

External Visual

The purpose of this examination is to verify that the materials, design, construction, markings, and workmanship of IC components are in accordance with the applicable procurement document.  This test is considered non-destructive and is used for package qualification, monitoring, process or lot acceptance.

Physical Dimension

The purpose of this examination is to verify that the external physical dimensions of IC components are in accordance with the applicable package outline drawing. This test is considered non-destructive and is used for package qualification, monitoring, process or lot acceptance.

Radiographic X-Ray

A radiographic method of detecting internal defects inside the IC components such as foreign materials, wire-bonding problem, package and epoxy voids, in the die attach material.  This test is considered non-destructive and is used for package qualification, monitoring, process or lot acceptance.

Scanning Acoustic Tomography (SAT)

This is a qualitative method of using an acoustic imaging technique to detect delaminations in material interface, cracks and voids inside the plastic IC components.  This technique is also known as Scanning Acoustic Microscopy (SAM).   This test is considered non-destructive and is used for package qualification, monitoring, process or lot acceptance.

On-Going Reliability Testing (ORT)

An On-Going Reliability Test (ORT) is used to help derive a reliability figure through testing.   An ORT can also point out weaknesses and failure modes that occur over time.   An ORT is very similar to the Reliability Demonstration Test (RDT) except that the RDT is usually performed once just prior to release of the product, whereas the ORT is an on-going test rotating in samples from the manufacturing line.

Reliability Demonstration Testing (RDT)

Reliability Demonstrated Testing is an efficient way to test whether the product will attain a specified life. This life is typically the target MTBF of the product.

RDT's can utilize HALT data to provide useful life data. Whilst HALT is a product improvement process, RDT is an excellent tool for extracting statistically correct life data through the use of acceleration factors.  Acceleration factors can be determined in a variety of ways, each using mathematical formulas based on the stress applied. Some of the acceleration stresses include:

• Steady state elevated temperature
• Temperature cycling
• Power cycling
• Humidity
• Temperature and humidity, or pressure
• Vibration
• Electrical Stress

RDT is ideally performed when the product development is stable, with all design flaws removed. For most companies RDT is performed at either the Pilot Production phase, or first mass production as a final qualification before initiating full blown production.

Accelerated Life Testing (ALT)

ALT is performed to gauge the products useful life time, or to provide statistical confidence in the specified MTBF figure.  ALT is quantitative in nature, and usually consists of running tests at higher than normal stress levels to accelerate the time to failure, or time to qualification.

ALT can also be conducted for one of two goals: qualitative testing and quantitative life testing.

Qualitative testing means we are attempting to identify failures without consideration for calculating the standard unit life in ambient operating conditions. Quantitative testing refers to using and ALT to predict the useful life of the product to gauge confidence in the unit ability to survive a stated MTBF at ambient operating conditions.

Acceleration Methods

There are a wide range of acceleration methods available for use. Selecting the most appropriate stress to apply is done by evaluating the product's application and expected stresses that will be encountered during day to day use.

Some common models for calculating acceleration factor include:

• Arrhenius
• Eyring
• Coffin-Mansen
• Norris-Landzberg
• Inverse Power Law

ALT's are ideally performed when the product is nearing it's final design changes. This ensures that the test is conducted on mass production quality samples and will provide the most accurate results.