关键词: 超细引线键合, 超声热压楔形键合, 工艺优化, 可靠性

Abstract: The surface roughening defects in aluminum alloy tube bending seriously deteriorate the surface quality and service performance. It is urgent to find out the rules of surface roughening formation during the forming process to avoid the occurrence of such defects. A macroscopic finite element model of tube bending cannot reasonably describe the mesoscale inhomogeneous deformation induced surface roughening behavior, while the mesoscale mechanical model can hardly be applied to the practical forming process with complicated boundary conditions. The representative volume element(RVE) meso-model based on Voronoi diagram and crystal plasticity theory is introduced into the macro finite element model to establish a three-dimensional macro-meso coupling model for aluminum tube bending. Then the above macro-meso coupling model is applied to study the surface roughening characteristics of the 5052-O aluminum tube during bending and systematically analyze the influence of microstructure parameters on surface roughening behavior during bending. The results show that the smaller the grain size, the smaller the strain difference between the grain interior and the grain boundary, the more uniform the deformation, and the smaller the surface roughness; for the model with mixture of Cube texture and Random texture, with the increase of the content of Cube texture, the surface roughness after bending deformation decreases; the coupling between the texture distribution and loading method affects the surface roughening behavior.

Key words: ultrafine wire bonding, ultrasonic hot-press wedge, bonding, process optimization