Reliability of thermal compression bond combine with non conductive paste process in fine pitch micro-bumps soldering

In order to meet the miniaturization trend and to reduce the power consumption for next generation devices, three-dimensional (3D) stacking is believed to be one of the technologies that can meet these requirements. In advanced 3D stacking technologies, one of the important steps is to develop and assembly fine pitch and high density microbumps. However, while the stacking chip size of top die and bottom die are similar, there is not enough space to dispense underfill, so it is a challenge for conventional underfill (CUF). In this paper, thermal compression bond (TCB) combine with non conductive paste (NCP) were studied. Adhesion between NCP and SiN, adhesion between NCP and PI, simulation of stress between bumps and chips were carried out and discussed. Finally, reliability test results were also reported in this paper.