Gold Vs Platinum
However, not all PCB manufacturers offer it, as they provide other alternatives. The use of Immersion Tin started primarily as a substitute for lead-based mostly surface finish. Other disadvantages include variations in thickness over small and enormous pads, making it unsuitable for High Density Interconnect merchandise that require uniform leveling. It is tough for manufacturers using HASL to control solder bridging on fantastic pitch circuits, and this makes HASL unsuitable as a surface finish for PCBs with fine-pitch SMDs and BGAs.
One disadvantage with ENIG is the migration of Nickel into the Gold layer. This shows up as the black pad syndrome, and ends in fractures and faulty board connections. Manufacturers additionally refer to Immersion Tin as White Tin, and apply it as a very thin layer of Tin on the Copper floor utilizing a chemical process.
HASL processbegins with the immersion of PCBs into the lead or molten tin answer to ensure that the uncovered copper space gets coated by the answer. After that, we used a hot air leveler to make sure even solder deposition. ENIG expertise also comes with the promise of less oxidation, low contact resistance, high energy, and antifriction. With ENIG know-how, the floor of the printed circuit board becomes easy to deal with, not forgetting that this technology provides wonderful plating around the holes within the PCB. While there are plenty of surface finishes, two of probably the most extensively used ones are HASL and ENIG plating.
Comparing the results of steam-age check information exhibits a clear good thing about EPIG over ENIG. After even a short length exposure to steam, ENIG finishes didn't solder. Much longer steam exposures produced little to no effect on EPIG plated samples.
As each layers of Nickel in addition to Gold are very thin and even, the floor end presents and perfect flat surface. Absence of any hazardous substances makes ENIG compatible to RoHS directives.
So, between HASL vs.ENIG, which one is the best or more superiorfinish? This article examines the performance characteristics of the 2, helping the viewers to decide on the suitable one, thereby saving time and materials costs. The search for a low-cost, Lead-free, and fine-pitch suitable floor finish has led to the event of Organic Solderability Preservative, commonly often known as OSP. Producing a skinny and uniform protecting layer, OSP is a superior floor finish over the more traditional ones, especially in regards to its co-planarity and solderability. ENIG is a perfect floor end for the most recent era of complex floor mount components corresponding to fantastic-pitch BGAs and flip chips.
The greatest solution to the black pad defect has been to deposit a layer of electroless palladium over the nickel layer. The Pd isn't etched away during the gold plating course of so the potential for black pad is eliminated. For this purpose, ENEPIG has turn into a well-liked alternative for digital merchandise that require high reliability (i.e. medical and aerospace).