PCB Processes: EPAG

Electroless Palladium / Autocatalytic Gold (EPAG)

EPAG facilitates the deposition of palladium over copper without a nickel layer. It has a relatively short cycle, is water and energy-efficient, and enables gold, silver and copper wire bonding.

Electroless Palladium

Talon 3 electroless palladium is the foundational process for EPAG – a critical final finish component as lines become tighter, space becomes more critical, and aversion to nickel becomes more common.

Talon 3 deposits an electroless / autocatalytic palladium that is solderable and gold wire bondable. The bath has a low palladium metal content and is highly stable. The rate of deposition and quality of the deposit are consistent throughout the product’s bath life. The EPAG finish developed with Talon 3 electroless palladium solders flawlessly after eight hours of steam aging.

Immersion Gold

Gobright® TLA-77 Type S immersion gold provides excellent solderjoint reliability, thanks to low porosity and low nickel dissolution. It operates at 0.4 g/l gold, minimizing inventory costs and drag-out losses. It is an ideal solderable finish for small SMT and BGA pads. The electrolyte needs one concentrate for make-up and an additional component for replenishment.

Reduction-Assisted Immersion Gold

Epithas® TWX-40 “RAIG” is a single immersion gold bath with autocatalytic capabilities. Shops can now deposit 4-8 μin gold in a single step. RAIG has a small coefficient of variation for gold thickness, which is advantageous for increasing circuit density. Where specs require high wire bond pull strength, the thicker gold enabled by RAIG fulfills this need. Finally, enabling the deposition of a uniform coating of gold on a very small wire-bond pad (or a plated through-hole) is a major performance advantage.

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.

Gobright® TMX-21/23 is an alternative autocatalytic gold, a neutral autocatalytic/ electroless gold process that meets IC and PWB wire bonding requirements. These stable baths have an extended service life. For gold deposits up to 30 μin, TMX-23 is recommended. For deposits over 30 μin, TMX-21 is the best option.

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Uyemura PCB finishes lead the world in plating performance.

EPIG (Electroless Palladium Immersion Gold) is a patented product and process of Uyemura.

For more details, or to arrange test processing,
contact your Uyemura representative.