Electrolytic Gold, Nickel-phos Electrolytes, Tin Whiskers Solution

Antitarnish 616 PLUS is an organic antitarnish process based on nanotechnology: special nanopolymers absorb on the metal surface and crosslink to form a protective layer a few nanometers thick. Antitarnish 616 PLUS provides invisible protection from tarnish and wear, while permanently preserving precious metal brightness. It also seals thin gold's inherent porosity more effectively than alternatives.

616's aqueous formula is chrome-free and RoHS compliant. It will not compromise solderability or bonding capacity, has low contact resistance, and preserves metal's inherent lubricity, making it suitable for plug connectors and other electronic applications. It can be used in rack, barrel, or reel-to-reel equipment.

Miralloy is a cost-effective alternative to silver, palladium and nickel for many connector and sensor applications. The newest Miralloy product, 2851, operates at 10 ASF, which is 25-43% faster than competitive products, providing substantial advantages in cycle time and cost.

Miralloy is an advanced alloy that deposits up to 15 µm with exceptional uniformity. Its average composition is 51% copper, 33% tin and 17% zinc. Deposits resist abrasion and corrosion, and are non-magnetic, so they're well suited to high frequency applications. It has excellent solderability, high hardness value, and good contact resistance values in sulphur-containing atmospheres. This versatile, lead-free finish is also tarnish-free, RoHS compliant, and RF-friendly. Slightly leveling deposits can be achieved at all current densities.

Miralloy has earned widespread acceptance for use on HF connectors, contact elements and solder pins. It is plated using standard rack equipment.

Soft Gold Electrolytes for Rack and Barrel Plating

Auruna 550 neutral electrolyte deposits pure gold coatings with a matte yellow appearance. It was engineered for use where lifting of fully aqueous resists is an issue and where excellent bondability and solderability are required.

Deposits exhibit excellent ductility, hardness below 90 HK25, low contact resistance, and 99.9% purity.

Auruna 550 deposits meet ASTM B488 Type III, Code A.

Auruna 551 mildly acidic electrolyte deposits thin, pure gold (0.05-0.1 µm) as gold strike layers for neutral or alkaline gold plating baths. It also provides adhesive activation of the basic material and protection of the main gold bath from contamination.

Auruna 553 neutral fine gold electrolyte produces silk-matte coatings of exceptional ductility. Deposits are up to 200 µm; hardness is approximately 90 HV 0.01. Auruna 553 has excellent soldering and bonding properties and meets ASTM B488-01, Type III, Code B.

Auruna 556 neutral electrolyte deposits hard and bright pure gold with a high current efficiency of 90%. 556 is well suited for use with PCBs where lifting of the resist by hydrogen should be avoided.

Auruna 5000 neutral electrolyte deposits a fine gold matte yellow microcrystalline coating. It was developed for use on flexible PCBs and rigid substrates.

PCBs are plated in matte nickel, strike gold plated, then coated in Auruna 5000. Gold layers exhibit excellent bondability and solderability, high ductility and low electrical resistance. Auruna 5000 layers are 99.95% pure gold, with as-plated hardness of 70-85 HV 0.025. Coating meets the requirements of ASTM B-488-01, Type III, Code A/B.­

Hard Gold Electrolytes for Rack and Barrel Plating

Auruna® 527 hard gold-nickel electrolyte minimizes gold consumption, delivers excellent throwing power in barrel plating operations.

Long-life, room temperature bath is mildly acidic, highly stable and impurities-tolerant; low deposition speed facilitates good thickness distribution, particularly for hollow parts.

Coatings exhibit excellent abrasion resistance and low contact resistance. Low gold content can be reduced from 4 g/to 2 g/l, to further reduce drag-out. Ideal for connector applications where masking is impractical.

Auruna 528 hard gold-nickel electrolyte provides high current efficiency, hardness of 150 HV 0.025. Solution can be run with high current density or reduced gold content; maximum coating thickness is 10 µm. Ideal for connectors, PCB with sensitive resists, and decorative applications.

Auruna 529 hard gold-cobalt electrolyte provides high current efficiency, hardness of 180 HV 0.025. The process has a high efficiency (65%) and a mildly acidic pH. Coating offers excellent abrasion resistance, with a maximum thickness of 10 µm.

Auruna 530 hard gold-cobalt electrolyte was developed for electrical contacts. Process provides high current efficiency, hardness of 170 HV 0.01. Bath is mildly acidic. Coating offers excellent abrasion resistance, with a maximum thickness of 5 µm.

Auruna 539 hard gold-cobalt electrolyte produces gold alloy deposits of 99.7% gold, alloyed with cobalt. Baths have excellent throwing power. Ultra-bright deposits have excellent corrosion and abrasion resistance, and a hardness of 200 HV.

Auruna 539 was developed for technical and decorative applications with low coating thickness requirements. It is well suited for pregilding and barrel gold plating. Process provides excellent deposit uniformity and a maximum thickness of 2 µm.

Tin Whiskers Solution

An important new technology from Uyemura prevents whiskers formation in electroplated tin for 22,000 hours – and longer.

GRX-70 is a unique, high-speed electrolytic plating process – a breakthrough in the control of tin whiskers. Whisker crystals of tin and tin-based alloys are the most common culprits in the short circuiting of electronic components. Most often, the cause of tin whiskers is compressive stress. The proprietary technology developed by Uyemura dissipates compressive stress, preventing whisker formation. GRX-70 is ideally suited for connectors and semiconductor lead frames.

Features include:

  • High purity anode
  • High deposition speeds for rackless and reel-to-reel processing
  • High deposition efficiency over a wide current density range
  • Bath is lead and fluoride free, and foam-resistant.
  • Operating range is 113-131°F, with 122° the optimum.
  • Film has a uniform white matt appearance; appearance after reflow is excellent. Carbon and sulfur concentrations in the film are very low.
  • Excellent solderability.

Read: The Elimination of Whiskers from Electroplated Tin.
by Masanobu Tsujimoto, Don Gudeczauskas, and George Milad

NEW Nickel-Phos Electrolytes Debut

Two important new Niphos electrolytes both generate huge energy savings as EN replacements, and exhibit less internal stress compared with existing Niphos electrolytes. The superior hardness, abrasion and corrosion properties inherent in Niphos products are identical.

NIPHOS® 967 plates via rack or barrel, was engineered for connectors. Used in combination with hard gold, it allows substantial reductions in gold thickness.

NIPHOS® 968 for barrel plating was developed to plate steel rods in hydraulics and shock absorbers: nickel-phosphorus layers are combined with chromium as a final layer. This combination allows lower thicknesses of the chromium and dramatically improves wear properties of the complete system.

New from Uyemura: Mixed Metal Oxide Anodes / MMO Anode

Metal oxide anodes are manufactured from precious iridium and ruthenium oxides, sometimes combined with non-precious tantalum and titanium oxides. Solutions of these metals are applied in layers in a multi-stage process; they are subsequently transformed in a thermal process into their catalytically effective shape.

For details see our MMO Anode page.


UYEMURA Corporate Headquarters:

3990 Concours, #425 • Ontario, CA 91764 • ph: (909) 466-5635


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