Packaging Reliability Testing and Evaluation of Gold Electrode NTC Chip Thermistor
NTC thermal gold electrodes/ silver electrode chip device failure mode of the main including electricity failure (such as short circuit or open circuit), light failure (such as high temperature lead to potting glue, optical performance degradation show, etc) and mechanical failure (such as lead, take off a fracture welding), and of these factors and packaging structure and the process. NTC thermal gold electrodes chip/silver electrode the service life of the chip to average failure time (MTTF) to define, for lighting purposes, generally refers to NTC thermal gold electrodes chip/silver electrode chip output flux attenuation for initial 70% (for display purposes, defined as 50% of the initial value the use of time. Because NTC thermal gold electrodes chip/silver electrode chips long life, usually take to speed up the environmental test method for reliability testing and evaluation.
Test content mainly includes high temperature storage (100 ℃, 1000 h), low temperature storage (55 ℃, 1000-h), high temperature and high humidity (85 ℃ / 85%, 1000 h), high low temperature cycle (85 ℃ ~-55 ℃), thermal shock resistance, corrosion resistance, dissolved, mechanical shock.
However, accelerated environment test is only one aspect of the problem, the NTC thermal gold electrodes chip/silver electrode chip forecasting life of the mechanism and method of the research is still the problem to study.