Wire Bonding Advances for Multi-Chip and System in Package Devices

Abstract

Wire bonding continues to be the most commonly used interconnection technology due to its low cost, high yield rate, increased flexibility and improved reliability. Among wire bonded packages, the high growth areas include Multi-Chip modules and System in Package (SiP) applications. A type of wire bonding, Stand-Off-Stitch Bond (SSB), is widely used in Multi-chip, die-to-die, SiP and light-emitting diodes (LEDs). The SSB process starts with a flat-topped bump bonding on the substrate or die, followed by the formation of a new ball bond (1st bond). The stitch bond (2nd bond) of that wire is bonded on top of the initial bump. This paper focuses on key SSB process steps, by examining the main challenges and solutions of SSB applications. We demonstrate ultra-fine pitch SSB process capability with 0.6 mil Au wire using newly developed response-based processes for sub-20 nm node wafer technology.