Combined loading and failure analysis of lead-free solder joints due to creep and fatigue phenomena

Abstract

Purpose – The aim of this work is the use of specially designed, authoring device to evaluate the strength of solder alloys commonly used in all kinds of electronic and electrical devices that are used in various fields of economic and industrial development to shorten the testing period. By obtaining answers to pervade science questions on how to properly investigate the reliability of solder joints can increase lifespan (uptime) of all electronic devices, and especially those that are used in the process submitted severe external conditions (dust, humidity air, heat, mechanical stress). Design/methodology/approach – The basic demand for performing the experimental tests is to measure small displacements (order of fractions of micrometers or of single microns) occurring within the sample. The analysis of the displacement values in various environmental conditions (temperature, humidity, current flow) allows estimating how a given material behaves also in a longer time, under normal operating conditions. Unlike a commonly used method, based on measuring the time-to-failure, at which the item is damaged due to accelerated aging, a behaviour of the sample is being tested for the selected duration time and the given loading conditions. Findings – The theoretical analysis and performed numerical simulations of ATC tests based on developed failure and reliability investigation system (FRIS) imply proposed here combined loading approach a promising and affective method for accelerated reliability tests. Both indentation and FRIS techniques by numerous possibilities of loading conditions seem to be appropriate in order to study the creep and fatigue behaviour. That kind of behaviours can be used by different models which characterize separately the mechanical properties under creep or fatigue tests. In case of creep mode, the displacement is expressed as a function of time where different parameters can be used to represent the creep sensibility. Originality/value – New device can provide both creep and fatigue phenomena simultaneously and perform tests in digital controlled environmental conditions. That approach enables faster method for testing reliability of solder joints.

Performance of SAC305 and SAC305-0.4La lead free electronic solders at high temperature

“…In solder joints, the formation of failure crack initiates at their corner and propagates along the region of strain concentration (Zhu et al , 2014). It is believed by different researchers in Chicot et al (2013), Jankowski et al (2014), Pei and Qu (2008a) and Ali (2015) that those solder alloys which have a better combination of strength and ductility also offer an acceptable resistance to fatigue. Based on these justifications by different researchers, along with the experimental observations in this study, it logically follows again that SAC-0.4La should show less fatigue behaviour due to lower combination of strength and ductility compared with SAC305.…”

Mechanical properties of thermally sprayed porous alumina coating by Vickers and Knoop indentation

“…Additionally, multicyclic indentation test can be performed by applying a constant indentation load at the same location or by applying increasing loading between minimum and maximum loads. As an example, Jankowski et al [23] shown that under constant multicyclic indentation loading applied to a massive Lead-Sean eutectic material after 1000 cycles, the indentation depth increases following a Manson-Coffin law representative of a fatigue behavior of their material. To avoid such fatigue influence, only 100 cycles have been applied and additionally using increasing loading mode thus reducing the effect of fatigue cycle since the depth increases following the supplement of load compared to the previous one and not to a plastic accommodation of the material under the same load.…”

Strength analysis of solder joints used in microelectronics packaging

“…All types of connections used on the mentioned packaging levels must meet the reliability requirements in order to ensure long-term and appropriate operation of the device. The current research was devoted to the analysis of the solder joint reliability used at the second packaging level [12].…”

“…This is a reason why in the case of engineering application the linear model is preferred. Figure 1 presents the hypothesis of linear damage accumulation and the problem of material hardening and softening phenomena for non-linear models [12].…”