Electronics Forum | Mon Jun 25 11:33:20 EDT 2012 | davef
The immersion silver is an active surface and readily combines with sulfur from the environment. Silver sulfide tarnishes the surface and creates doubt about the integrity of the finish at inspection. [uyemura.com/library-4.htm] Your customer's boar
Electronics Forum | Mon Jun 25 03:52:24 EDT 2012 | awtm
Our Customer had detected tarnished pad on ImAg PCBA and had conducted several SEM-EDX test at the soldermask below some of the chip resistors. High concentration of sulfur was found and it can be significantly reduced after further chemical cleaned
Industry News | 2014-09-18 17:55:32.0
SMTA China announcing that it presented awards for nine papers at the SMTA China South 2014 Conference Award Presentation Ceremony, held on Tuesday, August 26, 2014 at Shenzhen Convention & Exhibition Center in conjunction with the SMTA China Annual Award Ceremony.
Technical Library | 2022-03-16 19:48:18.0
Dendrites, Electrochemical Migration (ECM) and parasitic leakage, are usually caused by process related contamination. For example, excess flux, poor handling, extraneous solder, fibers, to name a few. One does not normally relate these fails with environmental causes. However, creep corrosion is a mechanism by which electronic products fail in application, primarily related to sulfur pollution present in the air.1 The sulfur reacts with exposed silver, and to a lesser extent, exposed copper. This paper will explore various aspects of the creep corrosion chemical reaction
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
Events Calendar | Tue Feb 18 00:00:00 EST 2020 - Tue Feb 18 00:00:00 EST 2020 | ,
Corrosion Testing For Electronic Equipment
SMTnet Express, March 17, 2022, Subscribers: 25,805, Companies: 11,547, Users: 27,113 Creep Corrosion On Lead-Free Printed Circuit Boards In High Sulfur Environments The material and process changes required to eliminate lead from
Surface Mount Technology Association (SMTA) | https://www.smta.org/icsr/speaker_forms/Paper-Format-Requirements.doc
] that the immersion silver surface finish selected for lead-free PCBs had the susceptibility to creep corrode when used in high sulfur and high humidity environments
