Cyanide-free chemical gold plating solution applied to advanced wafer packaging field and gold plating process thereof

Abstract

The invention discloses a cyanide-free chemical gold plating solution applied to the advanced wafer packaging field and a gold plating process thereof. The cyanide-free chemical gold plating solution is prepared from the following components: cyanide-free gold salt with the content of Au ions being 6-10 g / L, 10-60 g / L of a complexing agent, 10-60 g / L of conductive salt, 30-60 g / L of a buffer agent, 5-10 g / L of an anti-aging agent, 15-80 mg / L of an interfacial agent, 1-5 mg / L of a wetting agent, 50-80 mg / L of a reaction accelerator, and 0.2-5 mg / L of a stabilizer, wherein the reaction accelerator is a compound of 2,6-diaminopyridine and 3-pyridine methanol, and the mass concentration ratio of the 2,6-diaminopyridine to the 3-pyridine methanol is 2:1. The solution not only ensures the stability of the plating solution, but also enables a plated part to be easily spread on the surface of an electrode so as to achieve the purpose of uniform plating, and therefore the effect of void-free and seamless filling of wafer packaging micropores is further achieved.

Description

technical field [0001] The invention relates to the technical field of surface treatment, in particular to a cyanide-free chemical gold plating solution and a gold plating process applied in the field of advanced wafer packaging. Background technique [0002] The general orientation of wafer-level packaging is to perform most or all of the packaging and testing procedures directly on the wafer, and then cut it into a single component. Wafer-level packaging has a smaller package size and better electrical performance. At present, it is mainly used in various semiconductor products, and its demand mainly comes from the requirements of portable products for light, thin and small features. [0003] In the production process of wafer-level packaging products, when the copper lines are formed, other metals need to be formed on the copper lines to protect the copper lines and prevent oxidation. In addition, functions such as wire bonding and welding can be realized to form intercon...

AI Technical Summary

Problems solved by technology

The earliest electroless gold plating used cyanide-containing gold salts as raw materials. Due to the highly toxic cyanide contained in the cyanide plating solution, there will be great unsafe factors in the actual production process and related follow-up wastewater, waste gas treatment and disposal. The development of cyanide gold plating solution is limited. With the improvement of people's awareness of environmental protection, more and more cyanide-free gold plating processes are now used in the process, but the existing cyanide-free gold plating process also has the following defects:

[0005] 1) Gold plating is prone to defects such as voids and cracks during electroplating, and it is impossible to achieve perfect and seamless electroplating filling, and it is still impossible to achieve the effect of uniform plating

[0006] 2) There is a certain gap between the current efficiency and stability of the existing plating solution, the corrosion resistance of the coating and the brightness of the appearance and the cyanide coating

Images