-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueIPC 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.
The Cost of Rework
In this issue, we investigate rework's current state of the art. What are the root causes and how are they resolved? What is the financial impact of rework, and is it possible to eliminate it entirely without sacrificing your yields?
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
Tin Whisker Growth on the Surface of Tin-Rich Lead-Free Alloys
March 11, 2015 | A. Skwarek, K. Witek, M. Pluska, A. Czerwinski, Institute of Electron TechnologyEstimated reading time: 1 minute
The introduction of lead-free technology into electronics has intensified concern over tin whiskers phenomenon. Tin whiskers are crystals growing from the alloy surface as the result of compressive stress relaxation. This paper presents the dependence of tin whisker growth on copper and oxygen surface content. The observations and measurements were done using scanning electron microscopy with energy- dispersive X-ray spectroscopy. The results show that whisker growth is strongly related to increased copper and oxygen surface content in whisker neighborhood.
Introduction
Soldering is one of the oldest processes known to mankind. The proper solder joint is created by producing the metallic bond between the soldered elements and solder. In the 20th century, the most popular solder was Pb-37Sn63 eutectics. From July 2006, the use of Pb in solders is banned in the European Union as a consequence of RoHS directive. Actually, most of the lead-free alloys are based on Sn, containing in their composition also Ag, Cu, and small additions of Ni, Co, Ge or Sb. The introduction of tin-rich lead free solder has renewed the concern over, known for ages but limited by lead addition, phenomenon: tin whiskers. This phenomenon can significantly influence the reliability of solder connection and as a result influences the work of the entire PCB.
Tin whiskers are the crystals growing from the tin or tin alloy surface which can be dangerous for circuit reliability because of electrical current leakage and shorting due to bridging of adjacent conductors, metal vapor arcing (plasma) at low pressure, increased electromagnetic radiation, and damage from device littering by debris and contamination. The growth of tin whisker is caused by the compressive stress relaxation. The copper intermetallic compounds and surface layer of oxygen can strongly influence whisker growth. This paper presents the results of energy-dispersive X-ray spectroscopy (EDS) studies showing the relationship between tin whisker formation and copper and oxygen surface content in whisker neighborhood.
Editor's Note: This article originally appeared in the February issue of SMT Magazine.
Suggested Items
Indium Corporation to Present, Exhibit at EPP InnovationsFORUM
03/28/2024 | Indium CorporationIndium Corporation is set to present and exhibit at EPP InnovationsFORUM, one of Europe’s premier single-day electronics manufacturing forums, on April 17 in Leinfelden-Echterdingen, Germany. Topic areas for 2024 will include AI, automation, sustainability, and quality.
Reducing Nitrogen Consumption in Convection Soldering with Rehm Thermal Systems' Patented Mechatronic Curtain
03/28/2024 | Rehm Thermal SystemsCurrent developments indicate a need for larger throughput heights due to the trend towards e-mobility, which in turn increases nitrogen consumption for process inertization. Rehm Thermal Systems responds to this issue with an innovative solution: the mechatronic curtain.
Indium Corporation, Industry Partners to Showcase Products “Live@APEX”
03/26/2024 | Indium CorporationIndium Corporation®, in cooperation with its industry partners, will feature its proven solder solutions live on the show floor throughout IPC APEX Expo from Apr. 9‒11 in Anaheim, Calif., U.S.
ITW EAE Wins New Product Introduction Award for Electrovert® Wave Soldering Machine Deep Wave
03/26/2024 | ITW EAEITW EAE is proud to announce that it has earned a 2024 New Product Introduction (NPI) Award for Electrovert’s Deep Wave option for wave soldering machines. This new, innovative system provides the ability to pump up to a 20 mm wave height.
Mek's Next-Gen AOI Technology Takes Center Stage at IPC APEX EXPO 2024
03/19/2024 | MEKMek is excited to announce its presence at IPC APEX EXPO, North America's largest electronics manufacturing event, in Anaheim, California, from April 6-11, 2024. Attendees are invited to visit Mek at booth #1433 to explore the latest AOI technology offerings.