Pressure indicating film characterization of pressure distribution in eutectic Au/Sn wafer‐to‐wafer bonding

Abstract

Purpose

The purpose of this paper is to characterize pressure non‐uniformity in a wafer‐to‐wafer bond chamber using pressure sensitive paper.

Design/methodology/approach

Pressure non‐uniformity in a wafer‐to‐wafer bond chamber is characterized using pressure sensitive paper. The effect of poor pressure uniformity is discussed, and the non‐uniformity corrected for use in a eutectic Au/Sn based wafer‐to‐wafer bond.

Findings

Several types of under solder metallization were also investigated, with Nb/Au seed metal providing the best overall result with good solder compression, liquid proof seal and minimal solder spill‐out. Solder compression versus pressure applied was studied to achieve an excellent gap control (2‐3 μm) between the bonded substrates.

Originality/value

This paper shows that characterization of applied pressure measured directly at the substrate is an important aspect in the development of high yielding bond processes.

Citation

Spicer, D., Lai, K., Kornelsen, K., Brennan, A., Belov, N., Wang, M., Chou, T., Heck, J., Zhu, T. and Akhlaghi, S. (2010), "Pressure indicating film characterization of pressure distribution in eutectic Au/Sn wafer‐to‐wafer bonding", Microelectronics International, Vol. 27 No. 3, pp. 135-139. https://doi.org/10.1108/13565361011061920