AURUNA® SC-22 Gold Electrolyte

Cyanide-free gold electrolyte for the semiconductor industry

The cyanide-free gold electrolyte AURUNA® SC-22 was developed specifically for applications in the semiconductor industry. The electrolyte is based on sodium gold sulfite and features a stable, ammonia-free formulation with a wide operating window and easy handling. The electrolyte is pH-neutral to slightly alkaline (pH 7.5 - 9) and therefore has high resist compatibility.

The deposited gold layer has a purity of 99.9% and is free of pores and structural defects. It has a fine-grained microstructure with good planarity and uniform layer thickness distribution, even on complex geometries. The surface is smooth with a roughness between 5 and 40 nm, and the edges are sharp and precisely formed. The hardness of the layer is typically around 180 HV immediately after deposition. Subsequent heat treatment reduces the hardness to around 100 HV. The maximum achievable coating thickness is approximately 30 μm.

Advantages

• Cyanide- and ammonia-free
• Wide operating window
• Easy to use
• High resist compatibility
• Free of pores and structural defects
• Uniform layer thickness distribution
• High hardness

Applications

• Semiconductor applications
• Advanced packaging

Application for pillars and gold

Pillar structure – 26 μm Au

Cu/Ni/Au column with 1 μm Au