Gold electroplating solution
AssigneeEeja Ltd.
InventorsKoichiro Inoue, Junko Tsuyuki, Shinji Maeda, Yusa Imanishi
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Abstract
A cyanide-free gold electroplating solution for forming gold deposits contains bismuth and compact-packed via-filling deposit with a U-shaped stacked structure in cross section inside drilled holes. A gold electroplating solution includes 15 g/L of gold (I) sodium sulfite (as gold element), 15 g/L of sodium sulfate, 50 g/L of sodium sulfite, 10 mg/L of thallium formate (as thallium element), 50 mg/L of bismuth nitrate (as bismuth element) and 1 g/L of sodium phosphate.
Claims8
A cyanide-free gold electroplating solution for forming gold deposits containing bismuth preferentially over thallium and compact-packed via-filling deposit with a U-shaped stacked structure in cross section inside drilled holes, comprising the following basic elements and additional elements,
- said basic elements being:
- (a) gold (I) sulfite complex (as gold element) 1-30 g/L
- (b) sulfurous acid or sulfites 5-200 g/L
- (c) sulfate 3-150 g/L
- and said additional elements being:
- (d) bismuth catalyst (as bismuth element) 30-150 mg/L
- (e) thallium catalyst (as thallium element) 5-50 mg/L.
Dependencies are inferred from the claim text.