| 摘要 |
An electrical connection element of packaging substrate is disclosed. Wherein a plurality of conductive pads and a solder mask are formed on the surface of the packaging substrate, and a plurality of openings is formed in the solder mask to expose the conductive pads covered there beneath. The electrical connection element formed on the conductive pad comprises a core layer, a first covering layer and a second covering layer. The first covering layer covers the core layer, and the density of the first covering layer is higher than the density of the core layer. The second covering layer covers the first covering layer.
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