The primary purpose of surface finishing is to ensure good solderability or electrical properties. Because the natural copper tends to exist in the air in the form of oxide, it is impossible to keep the original copper for a long time, so the need for other treatment of copper, thus ENIG, HASL and other common processes.
What are the advantages of ENEPIG at PCBBUY?
Compared with other surface finishing, ENEPIG has the advantages of stable durability, excellent solderability, good compatibility, high flatness and suitable for high-density pads, so it can be used in more precise PCB, and has better solderability.
At present, the widely used gold sinking process, the principle is to wrap a thick layer of nickel gold alloy with good electrical properties on the copper surface, so as to protect the circuit board for a long time. Compared with precipitated gold, ENEPIG needs to add a layer of palladium between nickel and gold. Palladium can prevent corrosion caused by displacement reaction and make full preparation for ENIG. The gold can be tightly coated with palladium, providing a good interface.
Compare with other surface finishing
In the existing market, there are 4 primary lead-free final finishes for PCBs which are suitable for assembly of fine pitch QFP / BGA devices:
- Immersion Tin
- Immersion Silver
- Organic Solder Preservatives (OSP)
- Electroless Nickel Immersion Gold (ENIG)
The table below shows a comparison between these four final finishes and ENEPIG. None of the four primary final finish options is perfect for lead-free assembly, due to a variety of different concerns including multiple reflow cycle capability, shelf life before assembly and wire bond capability. In contrast, ENEPIG shows substantial advantages combining excellent shelf life, solder joint reliability, gold wire bondability and usage as a contact surface.
Why PCBBUY is professional at ENEPIG?
This process is not common because the nickel palladium has certain requirements on the process capacity of the plate plant, so many enterprises cannot find a suitable plate plant.
At present, PCBBUY has been fully online nickel palladium process, to solve the problem of enterprises. PCBBUY also supports a variety of complex processes, such as custom laminated structures, ultra thin sheets, large size boards, etc. As a professional PCB manufacturer of 1-8 layers, PCBBUY will continue to solve the problems of various precision boards and difficult boards for customers.