Immersion Silver, Immersion Tin, Electrolytic Palladium

Immersion Silver, Immersion Tin, Electrolytic Palladium

PRESA RGA-14 Immersion Silver (View Animation Clip)

The requirements of newer electronic parts have caused PCBs to evolve and demand improved manufacturing methods. One important requirement is high-density mounting. HASL exhibits poor thickness distribution and cannot meet the needs of high-density mounting.

The emphasis on environmentally favored products has also advanced the cause of eliminating lead. OSP's formulations are not capable of preventing copper oxidation under the higher-temperature assembly conditions associated with lead-free. Uyemura's RGA Immersion Silver was developed to meet those challenges.

Immersion silver is a simple process, with silver directly displacing copper in an immersion reaction. RGA-14 is a high productivity process, compatible with horizontal conveyorized equipment.

The RGA Immersion Silver deposit is uniform and meets thickness distribution criteria. It provides an ideal soldering surface under eutectic and lead-free assembly temperatures, and, with proper packaging and storage conditions, has an excellent shelf life.

Plating Bath
The Immersion Silver plating bath is very stable because the reaction is displacement-type. It does not decompose with UV light, and, because it is a low temperature process, will not attack the substrate or soldermask. The immersion silver deposits only on copper, and not on other areas (such as can be seen with auto-catalytic baths).


The RMK-31 Immersion Tin bath produces a highly uniform surface finish (thickness control is 1.5 standard deviation from the mean) that is ideal for backplane and other press fit applications. The flat microstructure has excellent aesthetics, and minimal copper etch-back. Solderability is excellent, even with high temperature solders and when subjected to lengthy storage. The finish is compatible with eutectic and lead-free solders. Tin is deposited only on the copper surface via displacement; process cycles are up to 3X faster than the competitive average.

RMK-31 is a highly differentiated immersion tin that combines ionic cleanliness, excellent appearance, exceptional uniformity, and processing speed that can triple both line capacity and productivity. It is designed to meet the robust requirements in shelf life, solderability and thickness uniformity for "Category 3 Coating Durability" per IPC Tin Specification 4554.

Electrolytic Palladium 457

Electrolytic Palladium 457 – is suitable for decorative and electronic applications. Slightly alkaline (7.7 pH) palladium electrolyte produces high-gloss, low-porosity coatings that are bendable and crack-free, up to 3 μm. Excellent corrosion resistance; stable electrolyte has a wide operating range of current density. Compatible with rack and barrel application; ideal for wire connectors, wire leads, automotive engine components and decorative parts, cabinet hardware, military equipment, printed circuit boards.