| abstract |
When using lead-free solder plating as a copper pillar-shaped cap layer, there is provided a method of plating at a uniform height on the top of each copper pillar in both cases within a die and across a wafer. SOLUTION: α as tin ion source, acid electrolyte, 0.0001-0.045 g / L first grain refiner, 0.005-0.75 g / L second grain refiner , Β-unsaturated aliphatic carbonyl compound, nonionic surfactant and water, and the first grain refiner is benzylideneacetone, dithiaalkyldiol, pyridinedicarboxylic, cinnamic acid, pyridinecarboxaldehyde, etc. An electroplating composition comprising a compound. [Selection figure] None |