The Formation process of themicro-welding compound by the ball-wedge method research

In this study, we researched the process of formation of welded crystal-circuitinterconnections of microchips with the use of gold wire using the "ball-wedge" method. The connection is formed in the solid phase due to severe plastic deformation in the contact zone. The complex of studies includes the modelling of the deformation process of the welding wire and the ball, X-ray phase analysis, modeling on physical samples. It is shown that the formation of a stable quality of welded joints cannot be ensured only by energy of ultrasound; it requires the additional activation of the welding zone, by means of heating or dynamic application of the loading force or modulation of the ultrasound energy. The intensity of plastic deformation in the contact zone increases significantly in case of uneven resistance of the metal to deformation, with a lower value near the welding zone. This will ensure the concentration of plastic deformation and shear stresses in the contact zone and ensure the production of high-quality welded joints. The studies carried out were taken into account in the development of thermal-sound welding installations using the "ball-wedge" method.