Chemical gold
The increasing demand for fine and very fine line boards and the decrease of the packing factor of PCBs causes a growing market for chemical surfaces. Chemical gold is a very planar alternative with excellent oxidation properties. The surface chemical gold is composed of 3 – 5 µm Ni/0.05 – 0.1 µm Au.
PROS:
- long shelf life (approx. 12 months)
- suitable for fine pitch applications
- totally planar
- good wettability
- suitable for press fit applications
CONS:
- more expensive than HAL, lead free