Electronics Forum | Wed Aug 10 09:01:15 EDT 2005 | fctassembly
Hello Joseph, Sorry for the bad news but microcracking is a well known potential condition occuring with the SAC305 alloy. Microcracking is a condition being seen with many joints soldered with the SAC305 alloy. It is technically a shrinkage cavity
Industry News | 2018-11-14 15:48:25.0
Indium Corporation will feature its ultra-reliable Indium8.9HF Solder Paste series at IPC APEX EXPO 2019, Jan. 29-31, in San Diego, California, USA.
Industry News | 2021-06-17 15:18:27.0
Indium Corporation will feature proven products from its portfolio of high-reliability solder materials at the CEIA Wuhan Seminar on June 24 in Wuhan, China.
Technical Library | 2020-11-24 23:01:04.0
The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. The paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosivity with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology.
SnAgCuBi and SnAgCuBiSb solder joint properties investigations SnAgCuBi and SnAgCuBiSb solder joint properties investigations This study investigates the technological properties of quaternary or quinary alloys made by addition Bi or Bi and Sb
| https://www.eptac.com/wp-content/uploads/2007/10/webinar_eptac_10_17_07.pdf
Surface Mount Technology Association (SMTA) | https://www.smta.org/knowledge/proceedings_abstract.cfm?PROC_ID=5454
: Sn-Ag-Cu (SAC) solders generally have better thermal cycling performance than eutectic Sn-Pb. However, their performance deteriorates significantly as the harshness of the thermal cycle increases, and the high-Ag SAC solders that perform best in thermal cycling have relatively poor drop impact properties