Has the Time Finally Come for Tin-nickel Plating?
December 9, 2024 | Marcy LaRont, PCB007 MagazineEstimated reading time: 1 minute

In the 1980s, Electrochemicals, Inc. (now Electrochemical Products) made a significant shift from furniture and industrial goods to electronics and manufacturing. During this journey, a tin-nickel plating alloy was developed. In 1984, Mike Carano, a young engineer, published a paper on tin-nickel plating alloy, but after some initial attention, the plating solution fell into obscurity.
Today, PCB fabrication looks largely the same, yet changes are afoot, chiefly due to the demands for very fine feature capability on printed circuit boards, as well as environmental sustainability. So, in this fascinating conversation with Mike Carano and Happy Holden, we take another look at tin-nickel and its advantages in both performance and sustainability.
Marcy LaRont: Mike, please explain the unique metal properties of the tin-nickel alloy and why fabricators should consider this as a surface finish solution today.
Mike Carano: Tin-nickel is a metastable alloy. It is monatomic, meaning that no matter what you do with the chemistry or how you manipulate the grams per liter of one metal or the other (or the amps per square foot), it always comes out as 65% of one metal and 35% of the other. I’m not aware this is true with any other combination of metals.
Typically, if your chemistry is out of balance—if you have more tin in the solution than you have lead—you will plate more tin. It’s precisely why there are so many alloys out there. In that respect, tin-nickel is pretty amazing.
Happy Holden: When I was at Hewlett-Packard, Dr. Morton Adler from Bell Labs called me and said he wanted us to fab his boards using tin-nickel, because he knew we were using it. I plated the boards with tin-nickel and added a gold strike. This thin gold was cobalt-hardened and the final thickness was still only 3–5 microinches when we finished. About a month after I sent them back to Adler, I got another call. He said, “What the hell did you send me? We’ve completed our reliability testing and your 3–5 microinches on tin-nickel outperforms our 120 microinches of sulfamate nickel on our contacts and other relays.”
Continue reading this conversation in the November 2024 issue of PCB007 Magazine.
Suggested Items
Bourns Introduces Line Filter Series with Ferrite Toroid Core that Delivers High Impedance Over a Broad Frequency Range
05/30/2025 | BournsBourns, Inc., a leading manufacturer and supplier of electronic components for power, protection, and sensing solutions, introduced a new filter series designed with a ferrite toroid core. Bourns specifically engineered its SRF1360 line filters to deliver high impedance over a broad frequency range.
Honda to Co-develop Refueling Port Connecting System for On-orbit Satellite Refueling with Astroscale
05/30/2025 | JCN NewswireHonda R&D Co., Ltd., a research and development subsidiary of Honda Motor Co., Ltd., will co-develop a refueling port connecting system designed for on-orbit refueling of satellites, with Astroscale Japan Inc., a subsidiary of Astroscale Holdings Inc.
Kimball Electronics to Open New Medical Manufacturing Facility
05/30/2025 | Kimball ElectronicsKimball Electronics has announced the addition of a 300,000 sq ft manufacturing facility in Indianapolis centered on the medical industry.
CIMS to Exhibit at JPCA Show 2025
05/28/2025 | CIMSCIMS is excited to announce our participation at JPCA 2025 in Tokyo, Japan! Join us from June 4-6.
Pilz Names STARTEAM GLOBAL ‘Best PCB Supplier of 2024’
05/28/2025 | STARTEAM GLOBALSTARTEAM GLOBAL has been recognized by Pilz, a global leader in automation technology, as its Best PCB Supplier of 2024. The award honors STARTEAM GLOBAL’s outstanding performance in key areas including product quality, delivery reliability, communication, and global service.