Prevention or elimination of early failures
through artificial aging/qualification
- Prevention of early failures through pre-aging/accelerated aging tests
- Climate resistance
- Endurance testing
- Stress test
- Parameter tests
- ESD testing (testing of sensitivity with respect to electrostatic discharges)
- Leak testing (helium leak testing)
Due to pre-aging in series production according to various standards and norms early failures are inhibited. This essential test service enables an increase of quality and reliability of a product.
Using a variety of possible methods (including burn-in, high temperature storage), artificial aging anticipates operating time in quick-motion.
In high temperature storage (HTS), for example, the components are stored in a high temperature cabinet at temperatures between e.g. 100°C and 150°C (depending o the component). The storage duration results from the desired acceleration factor. In case of static burn-in components are aged in the burn-in cabinet under supply voltage for e.g. 168 hours at 125°C which corresponds to an approximate operating time of half a year. Since the failure rate of many components follows the typical course of the bathtub curve, the early fails usually caused by variations of quality can be clearly identified and sorted out after testing and evaluation of the components.
Whether components meet the corresponding data sheet values or customer specifications, is determined with the aid of the qualification, which is especially important for safety-relevant or automotive applications before the final series application. In the case of a qualification, after a logged parameter measurement at new parts, components of the same type undergo various procedures of pre-aging or simulation corresponding to the conditions of the future field of application (e.g. climate test). During this treatment intermediate measurements and a final measurement after completion are made. If, during the subsequent tests, measurement deviation for parameter measuring occur due to the changed ambient conditions (e.g. high temperature and humidity, electrostatic charge), these must be interpreted and evaluated individually.
Methods for the inspection of the climate resistance:
- Static burn-in (constant parameters)
- Dynamic burn-in (variation of different parameter)
- Temperature storage (between -60 °C and +250 °C)
- Dynamic high temperature storage / thermal cycling conditions
- Thermal shock
- Tests at controlled temperature and humidity (constant or cyclic)
- Pressure Cooker Test, e.g. HAST (Highly Accelerated Stress Test)
Tests with thermal shock between -60 °C and +125 °C are in particular essential for the aerospace and military industries
Stress tests and endurance tests can usefully complement the qualification process. In this way components can be qualified through many different endurance tests for example according to AEC-Q100/200 to be applied in the automotive sector. Further analytical investigations, e.g. with regard to changes in the component contacts due to temperature, are possible by means of a large number of analyses (e.g. X-ray, microsectioning, microscopic examinations).