AURUNA® 5100 Pure Gold Electrolyte

Pure gold coatings with very good bonding and soldering properties

AURUNA® 5100 is a neutral fine gold electrolyte for depositing matt, lemon-yellow coatings. It's specifically developed for applications requiring excellent bonding and soldering properties.

In addition to good ductility, the layers from AURUNA® 5100 also exhibit a low hardness and a low contact resistance. Even under production conditions, the layers have a high gold purity of 99.99 wt. % Au.

The coatings meet the requirements of ASTM B488-01, Type III, Code A/B.

Electrolyte characteristics

Electrolyte type


Metal content

5 (4 - 8) g/l Au

pH value

6.0 (5.8 - 6.2)

Operating temperature

65 (60 - 70) °C

Current density range

0.2 (0.1 - 0.5) A/dm²

Plating speed

Approx. 0.13 μm/min at 0.2 A/dm²

Anode material

Pt-Ti (type PLATINODE® Pt/Ti)

Coating characteristics


Fine gold


99.99 wt.% Au

Colour of deposit





85 HV

Density of the coating

Approx. 19 g/cm³


  • Neutral electrolyte for pure gold coatings with very good thickness distribution
  • High current efficiency
  • Resist-friendly operating conditions
  • Excellent bonding and soldering properties
  • Low contact resistance
  • Classification according to ASTM B488-01 Type III, Code A/B
  • Compatible with standard BGA requirements
  • Easy maintenance and high stability of the electrolyte


  • Rigid and flexible printed circuit boards
  • Semiconductors
  • BGA applications
  • Ceramic and metallic substrates

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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

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