Research On Impact Of Solder Joint IMC Reliability In3D IC Package

With consumer electronics products are becoming more lightweight and miniaturization,3D IC packaging, such as flip-chip package and chip stacking, becomes the developingtrend of electronic package industry, having advantages of excellent electrical propertiesand a small volume package, etc.3D IC package still exists reliability issues in use. Dueto test experimental time-consuming, this article uses the finite element method toverify its reliability. This paper is focused on two types of structure in the3D IC chipstack package, including flip chip package and IMC solder joints structure, andinvestigates the mechanical behavior under cyclic temperature load, respectively. First,in flip chip package, to explore the reliability effect of solder ball shape parameters,such as solder ball height, contact angle, etc. The smaller Solder ball contact angle canimprove the reliability of solder balls, while solder ball height reduction will reduce thelife of the solder ball, and both above effects exist. Underfill is indispensable for flipchip package. Further, in3D IC chip stack structure, to inquiry the impact of twodifferent IMC joints, both Cu/Sn and Cu/Ni/In, on the failure mode of package structure.Indium-layer is used for the bonding material as a stress buffer layer, instead of theCu/Sn IMC structure, so that decrease the maximum stress of silicon die and can protectthe silicon chip effectively.