Experimental methodology for low temperature vibration investigations on electronic modules

This work represents a new contact-free measurement method to investigate vibration loads on a printed circuit board (PCB) test vehicle excited by a shaker in a low temperature environment. The aim is the insitu data acquisition without effecting the deflection of the PCB. In future researches of reliability investigations of solder joints it will be necessary to analyze the solder joint's stress caused by combined load of temperature and vibration variations. A capacitive sensor is used to measure the distance between the sensor and a measuring surface of the test vehicle. With an adequate (high) sampling rate, it is possible to measure oscillations of the test vehicle. A sinusoidal vibration load is defined by its amplitude and frequency, which can be determined by the measured distance signals well as a variation of frequency. From the distance signal during the cool down process it is possible to infer the stress of the PCB caused by thermal contraction of the used materials. This behavior can be influenced by different clamping variants of the PCB. Furthermore, the PCB amplitude decreases over the experiment time caused by a shift in frequency.