ENIPIG is Electroless Nickel Immersion Palladium Immersion Gold, is different from ENIG ( Nickel + Au ) , Between nickel and Au, Add one more PA Layer .ENIPIG = NI + PA + Au . PA will prevent NI and AU migration , stop the black happen
As early as 1990s, due to PCB manufacturing development towards finer lines and micro vias plus protruding disadvantages of HASL and OSP, like flatness issues of the former and flux elimination issues of the latter, ENIG started to be used as another alternative for surface finish in PCB fabrication.
In order to defeat black nickel board, the leading weakness of ENIG, ENIPIG comes out as an upgrading version of ENIG. With plating palladium added between electroless nickel and immersion gold, ENIPIG results in containing a thin layer for resistance whose thickness usually falls in the range from 0.05μm to 0.1μm. Palladium layer plays a role in stopping immersion gold technology from corroding nickel layer. As a result, ENIPIG is capable of defeating the defect of black pad held by ENIG. Furthermore, ENIPIG features highly-reliable wire bonding capability, excellent multiple reflow soldering capability and contains switch contact surface, which makes it able to meet stringent requirement of PCBs with high density and multiple surface packages simultaneously. Based on those advantages, ENIPIG is also called universal finish.
ENIPIG technology was applied in PCB fabrication as early as 1980s. However, ENIPIG wasn’t been massively used and popularized as a result of its high cost and products’ low requirement in terms of surface finish. At present, the requirements of miniaturization, thinness and multiple functions give more opportunities to ENIPIG.
The 7 Advantages of ENIPIG PCB Surface process
1. Excellent multiple reflow cycles
2. Capable of ensuring good solderability
3. Highly reliable wire bonding capacity
4. With a surface as key contact
5. High compatibility with Sn-Ag-Cu solder
6. Available for multiple packages, especially for PCBs with multiple types of packages
7. Black pad free
ENIPIG is one of PCB Surface
There are so many final surface finish options to choose from today, how do you decide which is best ? HASL – lead and lead –free, Immersion Tin, Immersion Silver, ENIG, OSP, and ENIPIG are the primary finishes used in PCB fabrication. Fabricators and assemblers generally work with the majority of these surface finishes to be able to support their customer’s requirements. So, the question is, with all of these available.
NIPDAU – Nickel-Palladium-Gold
DIG – Direct Immersion Gold
NCG – Nickel Copper and Gold
NCGI – Nickel Copper and Gold Interests
NBR – Nickel nickel nickel nickel BR
NNO – Nickel Nickel Oxide
EDL – Electroless Discharge Lamp
NIMH – Nickel Metal Hydride (Ni Is The Chemical Symbol For Nickel)
EBT – Electroless Bath Treatment
ELD – Electroless Deposition
ELS – Electroless Solution
Enbo – Electroless Nickel-Boron
EN – Electroless Nickel
Ni-au – Nickel-Gold
Ni-nio – Nickel-Nickel Monoxide
Ni-pd – Nickel-Palladium
ENP – Electroless Nickel Plating
ENEP – Electroless Nickel Electroless Palladium
ENEPIG – Electroless Nickel Electroless Palladium Immersion Gold
9 Things to think about when selecting a final surface finish:
1. Does the application require lead or lead-free assembly ?
2.Will the end environment have extreme temperatures or humidity concerns ?
3.What shelf life is needed? Will it be months or years ?
4.Volume and throughput
5.Does the design have fine pitch electronic components ?
6.How many assembly cycles will be required ?
7.Is this a RF or high frequency application ?
8.Will probeability be required for testing ?
9. Is thermal resistance required ?