Double-sided Electroplating Process for Through Glass Vias (TGVs) Filling

Abstract

This article reported a through-glass vias(TGVs) plating technology based on glass substrates. As one of the important technologies for continuation of Moore's law, through holes play the role of electrical connection on both sides. The TGVs were formed by laser drilling on the glass substrate, sputtering titanium as a barrier layer, and copper as a seed layer, and its diameter-to-depth ratio was about 1:4. Due to the difference in the layout of the metal wiring on both sides of the wafer, there is a difference between the plating area on both sides of the wafer and the current distribution during electroplating. Therefore, the double-sided electroplating technology reported in this article has successfully achieved void-free hole filling through convection strength, additives, current density, conduction mode, and can ensure that the uniformity on both sides meets the requirements. This electroplating technology has been used in mass-produced products, and can also realize copper filling in through holes of other structures.