Posts Tagged ‘ENIG’

When ENIG Doesn’t Solder.

Sunday, November 25th, 2012

One of the misconceptions about Electroless Nickel Immersion Gold (ENIG) is that it remains solderable for an unlimited amount of time. This misunderstanding is based in the fact that gold is a noble metal. Noble metals are metals that are resistant to oxidation and corrosion. Hence the belief that ENIG remains solderable since gold is the metal that we see. Some people in the electronics industry are surprised when they learn that ENIG has a solderable shelf life of (more…)

When to apply ENIG.

Saturday, August 1st, 2009

ENIG (Electroless Nickel Immersion Gold) is applied to the bare copper of a printed circuit board during the fabrication process. When in the fabrication process should be a concern to the contract manufacturer or OEM responsible for assembling the components onto the bare board. If a fabrication drawing states that the printed circuit board shall have SMOBC (Solder Mask Over Bare Copper) then ENIG must be applied after the application of solder mask. There are some exceptions to the rule. (more…)

ENIG (Electroless Nickel Immersion Gold)

Friday, July 31st, 2009

There are many benefits to Electroless Nickel Immersion Gold (ENIG). The first benefit is a very flat and level surface to solder to. This makes ENIG ideal for fine pitch surface mount devices. Another benefit is that the nickel strengthens the structure of the plated through hole. There are some drawbacks to ENIG. ENIG is an unforgiving process. Once the coating is applied there is no going back. Techniques that could be used to remove the finish are also damaging to the copper. Tight chemical and process controls need to be in place at printed circuit board manufacturers in order to provide a quality coating of ENIG per IPC-4552. Defects with the ENIG plating process may not be discovered until (more…)