Electronics Forum | Mon May 20 09:24:32 EDT 2013 | davef
SAC / Ni interface is the IMC (Cu, Ni)6Sn5
Electronics Forum | Mon May 20 22:13:45 EDT 2013 | ultimatejoker
So u mean it is to form the intermetallic compound which is (Cu,Ni)6Sn5?
Industry News | 2012-01-13 12:42:50.0
Nihon Superior Co. Ltd., a supplier of advanced soldering materials to the global market, announces that Senior Technical Advisor Keith Sweatman will present “The Stability of Cu6Sn5 in the Formation and Performance of Lead-free Solder Joints” at the SMTA Pan Pacific Microelectronics Symposium.
Industry News | 2012-02-07 16:20:22.0
Nihon Superior announces that its Senior Technical Advisor Keith Sweatman will present the paper titled “Effect of Cooling Rate on the Intermetallic Layer in Solder Joints” at the upcoming IPC APEX Expo.
Technical Library | 2013-02-28 17:14:36.0
While it has long been known that the Cu6Sn5 intermetallic that plays a critical role in the reliability of solder joints made with tin-containing alloys on copper substrates exists in two different crystal forms over the temperature range to which electronics circuitry is exposed during assembly and service, it has only recently been recognized that the change from one form to the other has implications for solder joint reliability. (..) In this paper the authors report a study of the effect of cooling rates on Cu6Sn5 crystals. Cooling rates from 200°C ranged from 10°C/minute to 100°C/minute and the effect of isothermal ageing at intermediate temperatures was also studied. The extent of the phase transformation after each regime was determined using synchrotron X-ray diffraction. The findings have important implications for the manufacture of solder joints and their in-service performance... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Technical Library | 2019-06-20 00:09:49.0
It is well known that during service the layer of Cu6Sn5 intermetallic at the interface between the solder and a Cu substrate grows but the usual concern has been that if this layer gets too thick it will be the brittleness of this intermetallic that will compromise the reliability of the joint, particularly in impact loading. There is another level of concern when the Cu-rich Cu3Sn phase starts to develop at the Cu6Sn5/Cu interface and an imbalance in the diffusion of atomic species, Sn and Cu, across that interface results in the formation at the Cu3Sn/Cu interface of Kirkendall voids, which can also compromise reliability in impact loading. However, when, as is the case in some microelectronics, the copper substrate is thin in relation to the volume of solder in the joint an overriding concern is that all of the Cu will be consumed by reaction with Sn to form these intermetallics.This paper reports an investigation into the kinetics of the growth of the interfacial intermetallic, and the consequent reduction in the thickness of the Cu substrate in solder joints made with three alloys, Sn-3.0Ag-0.5Cu, Sn-0.7Cu-0.05Ni and Sn-1.5Bi-0.7Cu-0.05Ni.
SMTnet Express February 28, 2013, Subscribers: 26214, Members: Companies: 13305, Users: 34373 Effect of Cooling Rate on the Intermetallic Layer in Solder Joints While it has long been known that the Cu6Sn5 intermetallic that plays a critical role
SMTnet Express, June 20, 2019, Subscribers: 32,068, Companies: 10,815, Users: 24,854 Dissolution in Service of the Copper Substrate of Solder Joints Credits: Nihon Superior Co., Ltd. It is well known that during service the layer of Cu6Sn5
