Surface Finish

ENIG / lead-free HASL / electroless immersion tin

Electroless nickel gold, HAL lead-free and immersion tin surface are offered for all types of manufacture and locations. Please note the following exceptions:

HDI Microvia and Flex printed circuit boards can only be manufactured in conjunction with electroless nickel gold or immersion tin.

Useful information about our surfaces
Surface	Thickness	Storability	Notes
Chemical nickel-gold (ENIG)	4-7 μm Ni 0,075 ± 0,025 μm Au	12 months	- low process temperature (approx. 90 °C) - smooth coating - suitable for aluminium wire bonding
HAL lead-free (Hot-Air-Leveling)	1-40 μm	12 months	- high process temperature (D9265-280 °C) - increased Cu removal, dependent on layout
Chemical tin (Sn)	0,8-1,1 μm	6 months	- low process temperature (approx. 70 °C) - smooth coating - growth in the intermetallic phase between Cu and Sn - layer thickness >1µm required for multiple soldering - rapid processing in the assembly process

You need a surface for gold wire bonding? Than send us your enquiry, we would be pleased to submit you an offer!

Hard gold

Hard gold is only done in combination with connector contacts. Full-area plating is not possible.

Please follow the rules regarding the gold connectors.

Hard gold: Design tip

The thickness of our surface is 1-3µm gold and 4-7µm nickel.

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The surface finish of your PCB is designed to protect against oxidation. It also allows for easier soldering of your PCB.

HAL lead free

The Hot Air Solder Levelling (HASL lead free) produces a homogeneous tin coating. This finish provides longer shelf life and good solderability.

Electroless nickel / immersion gold and Immersion Tin

For the electroless nickel / immersion gold and immersion tin surface finish, a thin metal coating is applied onto your PCB using a chemical process. An advantage over HASL lead free is the defined thickness of the metal coating. In addition, we can create thinner conductive patterns on the PCB. For this reason, WEdirekt only offers immersion surfaces for our HDI microvia printed circuit boards.

The shelf life of the electroless nickel / immersion gold and lead-free HASL surface finish is twelve months. Immersion tin has a shelf life of a maximum of six months.