| 摘要 |
1506380 Gold electro-plating ENGELHARD INDUSTRIES Ltd 21 Nov 1975 [4 Dec 1974] 52520/74 Heading C7B An aqueous gold plating electrolyte solution, for plating Ni-Fe substrates, e.g. transistor headers or integrated circuit flat pack lead frames employed in producing semi-conductor devices, to permit bonding of Ge or Si chips or slices to the substrates, consists of water, Au e.g. 1 to 100 g/l as an alkali metal (preferably K) Au(CN) 2 , at least one conducting compound e.g. in total 1 to 200 g/l selected from alkali metal (e.g. Na or K) acetate, (tetra or meta) borate, orthophosphate, nitrate sulphamate, sulphate, tartrate, thiocyanate, thiosulphate and boric acid, and if required a buffer salt e.g. 1 to 200 g/l K or ammonium H 2 PO 4 . Preferably the solution has a pH 4 to 8 and density 2 to 12 degrees BÚ. Plating may be effected at a cathode CD of 1 to 2000 ASF and at 20 to 90‹C with vigorous agitation. The electrolyte may be applied only to selected areas of the substrate as a high velocity jet. |
