AURUNA® 8100 Gold Cobalt Electrolyte

High-speed electrolyte for hard gold coatings

AURUNA® 8100 is used for depositing hard gold coatings in special high-speed equipment. The weakly acidic high-speed electrolyte has a wide operating range with easy bath maintenance and extremely high plating speed.

AURUNA® 8100 was specifically developed for the automatic high-speed gold-plating in equipment for selective plating and continuously working reel-to-reel lines. Due to vigorous electrolyte agitation (flow, spray), it allows the working at high current densities with stable long-time behaviour. It can be also operated as a gold strike electrolyte.

The deposits are solderable, low in pores, ultra-bright, hard and abrasion-resistant. They have a constantly low contact resistance. Therefore the electrolyte is excellently suitable for the gold-plating of electronic components such as connectors, contacts and edge connectors on printed circuit boards.

The optional use of the AURUNA® Inhibitor 2 offers the possibility of a reduced gold consumption of up to 15%. The inhibitor allows sharp borderlines - this reduces the size of the run-off area. Of course, the layer properties remain unaffected. The inhibitor can be removed without any residue after the plating by cleaning with activated carbon.

Electrolyte characteristics

Electrolyte type

Weakly acidic

Metal content

12 (2 - 30) g/l Au

pH value

4.2 - 4.6

Operating temperature

55 (45 - 65) °C

Current density range

2 - 80 A/dm², 80 A/dm² in JetLab

Plating speed

0.3 - 11 μm/min

Anode material

Pt-Ti (type PLATINODE® Pt/Ti)

Coating characteristics



Alloy composition

Approx. 99.7 wt. % Au
0.1 - 0.4 wt. % Co

Colour of deposit

Deep yellow




120 - 200 HV

Max. coating thickness

10 μm

Density of the coating

Approx. 17 g/cm³


  • Weakly acidic high-speed electrolyte
  • Wide operating range
  • Extremely high plating speed
  • Low-pore, solderable, hard and abrasion-resistant coatings
  • For electrical contacts
  • Classification according to ASTM B-488-01 Type I-II, Code C-D
  • The coatings are RoHS compliant
  • For use in high-speed equipment
  • Gold savings of up to 15% by inhibitor usage


  • Connectors
  • Electrical contacts
  • Edge connectors on printed circuit boards

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Questions about the product?

Markus Legeler

+49 7171 607 204

For inquiries and additional information
please contact

Umicore AG & Co. KG
Rodenbacher Chaussee 4
63457 Hanau-Wolfgang

Tel.: +49 (6181) 59 6005
Fax: +49 (6181) 59 2970

The information and statements contained herein are provided free of charge. They are believed to be accurate at the time of publication, but Umicore makes no warranty with respect thereto, including but not limited to any results to be obtained or the infringement of any proprietary rights. Use or application of such information or statements is at the user´s sole discretion, without any liability on the part of Umicore. Nothing herein shall be construed as a license or recommendation for use, which infringes upon any proprietary rights. All sales are subject to Umicore´s General Conditions of Sale and Delivery.