A thermoelectric cooler-based testing methodology for the rapid assessment of electronic packaging reliability

In this paper, we describe the implementation and results of a testing methodology that can significantly reduce the time required to determine the reliability of electronic packaging components. A series of thermal ball grid array (TBGA) packages were tested to determine their characteristic lifetime by two different methodologies: (a) thermal cycling between -40° and 125° with the standard accelerated temperature cycling test (ATC) using a convective temperature cycling chamber and (b) temperature cycling between 0° and 100°C with thermoelectric heat pumps that were placed in direct contact with the test devices. Using a custom-built instrumentation setup, we successfully tested up to four devices simultaneously, with the possibility to test many more. Using infrared thermography, it was shown that there was a significant lateral temperature distribution between the device-under-test (DUT) and the printed circuit board onto which it was mounted with the RCT test. This temperature distribution is very different from the isothermal temperature distribution experienced by the DUT during ATC test, and is believed to be more representative of actual field conditions. In both cases, the mean time to failure of the TBGA package was shown to exceed two thousand cycles with no early failures. Using a Weibull plot analysis the characteristic lifetime of the devices was determined for both the ATC and RCT tests. The difference between the two methodologies is shown to be less than 25%. By using the rapid cycling test (RCT) approach, the time required to estimate the reliability of the TBGA package can be reduced from three months to less than ten days, offering the possibility to significantly shorten the time required to develop and test new packaging designs.