Gold sulphite electroplating solutions and methods

摘要

An electroplating bath solution comprising an alkali metal or ammonium gold sulphite, a water soluble salt of thallium metal to effect brightening and grain refining, and a non-hydroxy, non-amino carboxylic acid such as formic acid and oxalic acid to ensure that the bright gold metal deposit has a hardness lower than about 90 Knoop. The method of depositing the bright gold metal on various substrates from such electroplating solutions is also described and claimed.