Trace Metals Analysis in High Purity Gold Using PlasmaQuant MS Elite Application Note · PlasmaQuant MS Elite

Introduction

Within the last decades, the demand and production of gold are continuously growing. The biggest demand is in the manufacturing of jewellery with a share of about 50 %. Furthermore, about 10 % of the yearly mined gold is used for manifold applications in the industry. Thanks to its peculiar properties like corrosion, chemical resistance, electrical conductivity and ductility, gold is widely used in electronics industry as material for electrical connections in mass manufactured electronic devices such as circuit boards, integrated chips and semiconductors but also in a variety of novel microelectronic devices like sensors. The well-known biocompatibility of gold has led to its medical use since ancient times. Also a large variety of new applications in high-tech areas, like nanomaterials, are becoming increasingly important.

As an important manufacturing technique, wire bonding is frequently used in microelectronics for the fabrication of conductive tracks in semiconductor applications. Such narrow wires made of gold are used to link one connection pad to another thus completing the electrical connection in an electronic device. Gold remains the most popular material for wire bonding especially when reliable manufacturing and applications in microelectronics packaging are required. High purity gold (> 99.999 %) is indispensable, since even the smallest contaminants can affect the manufacturing processes as well as the electrical and chemical properties of the material, resulting in hard spots, embrittlement, blistering, discoloration and insufficient properties of the manufactured conductors [1].

Elements to be determined include, depending on materials and processes used, Ag, Pd, Pt, Cu, Cr, Fe, Mg, Ni, Pb, Zn, Be, Ca, and Cd. The here presented application note discusses trace metal determination in high purity 5N gold (> 99.999 % gold) by means of inductively coupled plasma mass spectrometry (ICP-MS).