Three-dimensional model for electromigration induced evolution of flip chip solder joints

Abstract

Recent experiments have shown failure in flip chip micro solder joints induced by electromigration. This paper proposes a computational model to simulate the evolution of micro and sub-micro scale solder joints due to electromigration induced diffusion. Complicated morphological changes of the solder bump and multiple mechanisms cause a computational challenge. This is addressed by employing a diffuse interface model with multiple concentrations. To efficiently resolve complications, a semi-implicit Fourier spectral scheme and a biconjugate-gradient method are adopted. Results have demonstrated rich dynamics and solder breakage at the interface on the cathode side.

Intermetallic compound formation on lead-free solders by using microwave energy

“…Flip chip interconnect is becomes popular and rapidly growing microelectronics packaging technologies due to its high input/output (I/O) connect density, better electrical performance, high operating frequency, high throughput and low profile [7,8]. Moreover, nearly all large scale integrated circuit (IC) chips are packaged with flip-chip interconnect joints.…”

“…Moreover, nearly all large scale integrated circuit (IC) chips are packaged with flip-chip interconnect joints. In flip chip, solder joints are the interconnection between a die and the package carrier [7] where the chip is flipped over and the active (front) side is connected to the package substrate using a large number of tiny solder joints [8]. Since the joining process is a direct consequence of the interfacial reaction between the solder and substrate [9], understanding the growth of intermetallic compound (IMC) layer is one of critical parameter need to be considered.…”