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Early ENIG processes had poor adhesion to copper and lower solderability than HASL. In addition, a non-conductive layer containing nickel and phosphorus, known as "black pad", could form over the coating due to sulfur-containing compounds from the solder mask leaching into the plating bath.
77:, also known as "overall" or "selective chemical Ni/Au," respectively. The latter type is more common and significantly cheaper as less gold is needed to cover only the
58:, which protects the nickel from oxidation. The gold is typically applied by quick immersion in a solution containing gold salts. Some of the nickel is oxidized to
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Standard 4552A, while IPC standard 7095D, about ball array connectors, covers some ENIG problems and their remediation.
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Performance
Specification for Electroless Nickel/Immersion Gold (ENIG) Plating for Printed Boards
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component mounting), good oxidation resistance, and suitability for movable contacts such as
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while the gold is reduced to metallic state. A variant of this process adds a thin layer of
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218:". Standard IPC-7095D; first version issued in 2000, amended in 2004, 2008, and 2013.
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46:(PCBs), to avoid oxidation and improve the solderability of copper contacts and
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Design and
Assembly Process Implementation for Ball Grid Arrays (BGAs)
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The quality and other aspects of ENIG coatings for PCBs are covered by
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ENIG and ENEPIG are meant to replace the more conventional coatings of
205:". Standard IPC-4552A; first version issued in 2002, amended in 2012.
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66:over the nickel, a process known by the acronym
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214:IPC Plating Processes Subcommittee (2017): "
201:IPC Plating Processes Subcommittee (2017): "
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73:ENIG can be applied before or after the
181:"Surface Finishes in a Lead Free World"
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291:Printed circuit board manufacturing
183:. Uyemura International Corporation
244:. You can help Knowledge (XXG) by
147:Organic solderability preservative
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20:Electroless nickel immersion gold
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240:This metalworking article is a
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85:Advantages and disadvantages
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52:electroless nickel plating
135:Immersion silver plating
95:hot air solder leveling
44:printed circuit boards
141:Immersion tin plating
64:electroless palladium
16:Metal plating process
50:. It consists of an
48:plated through-holes
32:immersion gold (Au)
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79:solder pads
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285:Categories
164:References
107:connectors
93:, such as
117:Standards
40:soft gold
129:See also
187:6 March
28:ENi/IAu
91:solder
68:ENEPIG
149:(OSP)
143:(ISn)
137:(IAg)
242:stub
189:2019
56:gold
24:ENIG
123:IPC
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38:or
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60:Ni
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