-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueBox Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
Boost Your Sales
Every part of your business can be evaluated as a process, including your sales funnel. Optimizing your selling process requires a coordinated effort between marketing and sales. In this issue, industry experts in marketing and sales offer their best advice on how to boost your sales efforts.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
Tin Whiskers: Why Testing Temperature Can Change the Outcome
March 11, 2015 | Dr. Jennie S. Hwang, H-Technologies GroupEstimated reading time: 1 minute
Tin whisker phenomena have been observed and its potential mishaps have been recognized for more than six decades in electronic, electrical and industrial applications. For the recent several years, concerns about tin whiskers have been escalating, especially in the sector of high-reliability products. Increasing number of studies and tests has been carried out at various facilities, generating significant amount of quality reports and publications. In my recent tutorial at SMTA International Conference and Exhibition last September there were comments requesting to further discuss the plausible theories behind tin whiskers. When we examine the theories, temperature is one of the key variables that drive the phenomenon, mechanism and how the underlying science operates. So, let’s dedicate this article to the impact of external (testing) temperature and the science behind the impact.
JEDEC Solid State Technology Association (formerly known as the Joint Electron Device Engineering Council) has published several documents that address and/or are related to the testing of tin whiskers. The testing temperature as set in the documents are: ambient temperature storage (30 ±2°C and 60±3% RH); elevated temperature storage (60 ±5°C and 87+3/-2% RH); and temperature cycling are, practically speaking, as good as can be. However, refinements and selection of the testing temperature needs to be made when testing an "unknown" system. The system may possess specificities and contain certain compositions (e.g., active or inert additives [impurities]).
In metal whiskering, the physical metallurgy engaged in the process is complex and intricate—a compositional shift and /or an addition of extraneous elements to a base alloy system, regardless of sources, can change its whisker propensity enormously. As is known, the evidence of recrystallization and grain growth prior to whisker formation is presented for the “bright tin” deposit—large irregular shape grains are the precursors for whiskers. Recrystallization plays a part in tin whiskering process. To complicate further, however, tin whiskering is more than a classical recrystallization process and it is more than a classical stress relief phenomenon. I would say that, for a given tin-based material that is made by a given process, there is a “threshold strain” and a “threshold temperature” that cause tin whiskering.
Editor's Note: This article originally appeared in the February issue of SMT Magazine.
Suggested Items
KIC’s Miles Moreau to Present Profiling Basics and Best Practices at SMTA Wisconsin Chapter PCBA Profile Workshop
01/25/2024 | KICKIC, a renowned pioneer in thermal process and temperature measurement solutions for electronics manufacturing, announces that Miles Moreau, General Manager, will be a featured speaker at the SMTA Wisconsin Chapter In-Person PCBA Profile Workshop.
The Drive Toward UHDI and Substrates
09/20/2023 | I-Connect007 Editorial TeamPanasonic’s Darren Hitchcock spoke with the I-Connect007 Editorial Team on the complexities of moving toward ultra HDI manufacturing. As we learn in this conversation, the number of shifting constraints relative to traditional PCB fabrication is quite large and can sometimes conflict with each other.
Standard Of Excellence: The Products of the Future
09/19/2023 | Anaya Vardya -- Column: Standard of ExcellenceIn my last column, I discussed cutting-edge innovations in printed circuit board technology, focusing on innovative trends in ultra HDI, embedded passives and components, green PCBs, and advanced substrate materials. This month, I’m following up with the products these new PCB technologies are destined for. Why do we need all these new technologies?
Experience ViTrox's State-of-the-Art Offerings at SMTA Guadalajara 2023 Presented by Sales Channel Partner—SMTo Engineering
09/18/2023 | ViTroxViTrox, which aims to be the world’s most trusted technology company, is excited to announce that our trusted Sales Channel Partner (SCP) in Mexico, SMTo Engineering, S.A. de C.V., will be participating in SMTA Guadalajara Expo & Tech Forum. They will be exhibiting in Booth #911 from the 25th to the 26th of October 2023, at the Expo Guadalajara in Jalisco, Mexico.
Intel Unveils Industry-Leading Glass Substrates to Meet Demand for More Powerful Compute
09/18/2023 | IntelIntel announced one of the industry’s first glass substrates for next-generation advanced packaging, planned for the latter part of this decade.