Yu-Jie Huang

Awarded Honorable Mention at TwIChE.

Electroless copper plating is a solution-based copper deposition process driven by an autocatalytic redox reaction. Unlike electroplating, it does not require an external power supply. In the plating bath, copper ions are chemically reduced by a reducing agent, such as formaldehyde or glyoxylic acid, on catalytic sites located on the substrate surface. Once the initial copper nuclei are formed, the deposited copper can further catalyze the reaction, allowing continuous copper growth.

For non-conductive substrates such as glass, surface pretreatment and catalytic activation are necessary before plating. Pd/Sn activation or other catalytic seed layers are commonly used to provide active nucleation sites for copper deposition. Therefore, electroless copper plating is especially suitable for forming uniform copper coatings on insulating substrates, complex geometries, and high-aspect-ratio structures used in advanced semiconductor packaging.