METHOD OF DETERMINING SUBSTRATE MOUNTING QUALITY DURING ULTRASONIC MICRO-WELDING Russian patent published in 2020 - IPC B23K20/10 B23K31/12 

FIELD: acoustics.

SUBSTANCE: invention relates to acoustic methods of nondestructive testing and can be used at ultrasonic installation of wires on boards to control quality of mounting of any types of ceramic, fluoroplastic and composite substrates. Measurement of instantaneous current values of converter (I) and deformation of wire (d) is performed during micro-welding. Analysis of measurement results is performed in the time interval after the beginning of ultrasonic power supply to the welding zone. Evaluation of the oscillation range of instantaneous current values of ultrasonic transducer between their maximum I_max and minimum I_min values and estimating the span of instantaneous values of wire deformation between their maximum d_max and minimum d_min instantaneous value. Conclusion on absence of disruption of connection under contact pad between substrate and housing is made in case I_max-I_min < 3 mA at linear change of wire deformation without oscillations of its instantaneous values, and in case of I_max-I_min > 10 mA and d_max-d_min > 1 mcm there are concluded large discontinuities between connected objects.

EFFECT: invention enables finding large defects without X-ray microscopy, making conclusions on presence or absence of significant defects in the layer between connected objects.

1 cl, 7 dwg