A novel high speed impact testing method for evaluating the low temperature effects of eutectic and lead‐free solder joints

Abstract

2010),"Multidimensionality: building the mind/brain infrastructure for the next generation knowledge worker", On the Horizon, Vol. 18 Iss 3 pp. 240-254 http://dx.If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -The purpose of this paper is to present a novel high speed impact testing method for evaluating the effects of low temperatures on eutectic and lead-free solder joints. Interfacial cracking failure of Sn-based and Pb-free solders at subzero temperatures is of significant concern for electronic assemblies that operate in harsh environments. Design/methodology/approach -This paper presents a newly designed low temperature control system coupled with an Instron micro-impact testing machine, which offers a package level test for solder bumps, and that is used at subzero temperature ranges as low as 2408C. This study examined the failure characteristics of 63Sn-37Pb (Sn37Pb) and 96.5Sn-3Ag-0.5Cu (SAC305) solder joints at temperatures ranging from room temperature (R.T.) to 2 408C, and at impact speeds of 1 m/s. Findings -Three types of failure mode were identified: M1 interfacial fracture with no residual solder remaining on the pad (interfacial cracking); M2 interfacial fracture with residual solder persisting on the pad (mixed mode failure); and M3 solder ball fracture (bulk solder cracking). The experimental results indicated that the energy to peak load for both types of solders decreased significantly, by approximately 35 percent to 38 percent when the test temperature was reduced from R.T. to 2408C. In addition, the peak load of the Sn37Pb solder joint increased noticeably with a decreasing test temperature. However, the peak load of the SAC305 specimen remained virtually unchanged with a reduction in the temperature. The Sn37Pb solder joints failed in an M3 failure mode under all the considered testing temperatures. The SAC305 solder joints displayed both M1 and M2 failure modes at R.T.; however, they failed almost exclusively in M1 mode at the lowest test temperature of 2 408C. Originality/value -This paper presents a novel technique for evaluating high-speed impact strength and energy absorbance of Sn-based and Pb-free solders at the chip level within a low temperature control system. To overcome the drawb...

Failure Analysis of SAC305 Ball Grid Array Solder Joint at Extremely Cryogenic Temperature

“…Considering the special Pb-free material (SAC305) and the extreme environmental condition, the authors speculated that the failure was relevant to low temperature based on existing researches [25,26]. The other three memories of the failed circuit board were put into the tensile test.…”