DAIN SILVER GPE Process

The DAIN SILVER GPE Process is an innovative, completely cyanide-free silver plating system, consisting of an acidic strike bath (DAIN SILVER GPE-ST) and a thick plating bath (DAIN SILVER GPE-PL), engineered to deliver plating quality equivalent to conventional cyanide baths with enhanced environmental and performance advantages. This process eliminates cyanide compounds entirely, operates under strong acidic conditions negating pH control, and yields plating films with excellent adhesion and ductility. A significant capability is its direct plating on difficult substrates such as stainless steel and patterned printed circuit boards, a feat unachievable with traditional cyanide baths, alongside reducing wastewater treatment costs. Enhanced anti-tarnish properties are achieved when used with the NEW DAIN SILVER SERIES anti-tarnish agent. Applications include reel-to-reel and spouted plating for semiconductors, lead frames, and wires, as well as plating on articles vulnerable to alkaline solutions. Technical specifications for GPE-ST include a bath temperature of 20°C (15-25°C) and a current density of 2.5-5.0 A/dm², utilizing iridium oxide or Pt/Ti anodes. GPE-PL operates at 25°C (20-30°C) with a current density of 1.0-3.0 A/dm² and pure silver anodes, both baths maintaining strong acidity and requiring continuous filtration. The system demonstrates high cathode current efficiency (98-99%), good solderability, and superior ductility, evidenced by no cracking in mandrel tests on copper and stainless steel wires. Crucially, it facilitates silver plating on fine patterns without resist swelling, a common drawback of cyanide baths, and ensures robust adhesion on stainless steel substrates even after rigorous bending and heat resistance tests, offering a wide operating window for current density and flow rate to achieve semi-bright to bright deposits.