Sn/3.5Ag, Sn/0.7Cu, Sn/3.9Ag/0.6Cu, Sn/2.0Ag/0.7Cu (for Bar, Wire, Paste, BGA & Anode); Sn/Sb (for Bar); Sn (for Bar, Wire & Anode); Ni/Pd (for Bar, BGA & Anode); Conductive Adhesive (for Paste).
Electronics Forum | Sun Oct 13 08:53:46 EDT 2002 | greenman
TI found an improvement in solderability on their Ni/Pd lead-finishes by using inert (nitrogen) reflow, but this is an expensive operation for just one part.
Electronics Forum | Mon Jan 17 09:02:27 EST 2005 | russ
I have found that with the TI ni/pd platings that a peak temp of 226 C is the best for joint strength. Russ
Industry News | 2018-10-18 08:46:25.0
"Lead-Free" Semiconductor Industry
Industry News | 2002-12-03 15:00:11.0
Practical Components adds new formulations
Technical Library | 2014-11-06 16:43:24.0
This paper summarizes the results of recent investigations to examine the effect of electroless nickel process variations with respect to Pb-free (Sn-3.0Ag-0.5Cu) solder connections. These investigations included both ENIG and NiPd as surface finishes intended for second level interconnects in BGA applications. Process variations that are suspected to weaken solder joint reliability, including treatment time and pH, were used to achieve differences in nickel layer composition. Immersion gold deposits were also varied, but were directly dependent upon the plated nickel characteristics. In contrast to gold, different electroless palladium thicknesses were independently achieved by treatment time adjustments.
Technical Library | 2022-03-16 19:41:17.0
Creep corrosion occurs in electronics assemblies and it is reminiscent to electromigration but does not require electrical field to drive the reaction. Corrosive elements and moisture must be present for creep corrosion to occur. Sulfur is the most prominent element to cause creep corrosion in environments such as paper mills, rubber manufacturing, mining, cement manufacturing, waste water treatment etc., also including companies and locations nearby such industries. The main part of printed circuit board assembly (PCBA) to be affected is the PCB surface finish. Especially immersion silver is prone to creep corrosion, but it sometimes occurs in NiPd (lead frames), and to a lesser extent in ENIG and OSP surface finishes. As the use of immersion silver is increasing as PCB surface finish and electronics are more and more used in harsh environments, creep corrosion is a growing risk. In this paper we will present the driving forces and mechanisms as well as suitable tests and mitigation strategies against creep corrosion
