Electroless Nickel / Autocatalytic Gold (ENAG)
ENAG is a high-performing final finish for wire bondable deposits, and an excellent alternative to immersion chemistry, or ENEPIG. It deposits 120-240 μins of nickel, 8-40 μins of electroless gold.
Read “Neutral Auto-Catalytic Electroless Gold Plating Process” in the Uyemura library.
Electroless Nickel
Nimuden® NPR-8 nickel phosphorous plating solution was developed for fine line circuitry in electronic and PCB applications. Its higher phos content provides excellent corrosion performance, which can be further enhanced by increasing phos content. The phosphorous content in the deposited film remains constant regardless of metal turn-overs. NPR-8 has adhesive characteristics superior to electroplated nickel, is tolerant to dry film resist and soldermask, and is compatible with lead-free solders.
Immersion Gold
Gobright® TLA-77 Type S immersion gold provides excellent solderjoint reliability over time due to its low porosity and low nickel dissolution. It operates at just 0.4 g/l gold, minimizing inventory costs and drag-out losses. It is in ideal solderable finish for small SMT and BGA pads. The electrolyte needs one concentrate for make up and an additional component for replenishment.
Autocatalytic Gold
AuBEL Electroless Gold is an alkaline pH, autocatalytic process. It deposits at 80 μin per hour, and has excellent gold wire bond properties. The alternative for ENAG processing is TMX-23.
Gobright® TMX-21/23 is a neutral autocatalytic/ electroless gold process that meets IC (BGA, MCM, etc.) and PWB wire bonding requirements. These stable baths have an extended service life. TMX-21 was engineered for gold deposits over 30μin; for gold deposits under 30μin, TMX-23, with its lower deposition rate, is recommended.