A reliability evaluation of lead-free ball grid array (BGA) solder joints through mechanical fatigue testing

2005 ◽  
Author(s):  
C. Ryan ◽  
J. Punch ◽  
B. Rodgers
Keyword(s):  
Solder Joints ◽  
Fatigue Testing ◽  
Ball Grid Array ◽  
Reliability Evaluation ◽  
Lead Free ◽  
Mechanical Fatigue

SnAgCu Micro-Ball Grid Array (BGA) Solder Joint Evaluation Using a Torsion Mechanical Fatigue Test Method

2005 ◽  
Author(s):  
Claire Ryan ◽  
Bryan A. Rodgers ◽  
Jeff M. Punch
Keyword(s):  
Fatigue Test ◽  
Solder Joints ◽  
Fatigue Testing ◽  
Ball Grid Array ◽  
Test Method ◽  
Superior Performance ◽  
Cycle Number ◽  
Mechanical Fatigue ◽  
Number Of Cycles ◽  
Cycles To Failure

Due to the hazard which lead poses to health and the environment the EU is banning its use in electrical and electronic equipment from July 2006. This ban along with the market drive to more environmentally friendly products means that tin-lead solders must be replaced with lead-free alternatives. This paper presents the results of an experimental investigation of the mechanical fatigue properties of tin-silver-copper (SnAgCu) solder joints with a baseline of tin-lead (SnPb). The test vehicle comprised of an 8-layer FR4 printed circuit board (PCB) mounted with four micro-ball grid array (BGA) components — each with a total of 100 solder balls in a 10×10 array. The solder joints were formed using surface mount reflow processes optimised for both solder types. A torsion mechanical fatigue test was employed to evaluate the solder joints — the principle of which was to stress the solder joints repetitively in order to determine the number of cycles to failure. The BGA components were daisy-chained — the resistance across each daisy-chain was monitored continuously during the cyclic defection of the test board. A profile of the increase in resistance with cycle number was established and the number of cycles to failure determined. The failure mechanism induced by the cycling was examined using cross-section and scanning electron microscopy (SEM) techniques. The results for SnAgCu joints show a superior performance during torsion mechanical fatigue testing than SnPb joints; giving a greater number of cycles to failure. The results from the tests presented in this paper show that the torsion test method provides a viable alternative to ATC as a qualification method for solder joints, while also providing substantial time savings — taking weeks rather than months to complete.

Methodology for Analyzing Slip Behavior in Ball Grid Array Lead-Free Solder Joints After Simple Shear

2009 ◽  
Vol 38 (12) ◽  
pp. 2702-2711 ◽  
Author(s):  
Bite Zhou ◽  
Thomas R. Bieler ◽  
Tae-Kyu Lee ◽  
Kuo-Chuan Liu
Keyword(s):  
Simple Shear ◽  
Solder Joints ◽  
Ball Grid Array ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

Damage Evolution in Lead Free Solder Joints in Isothermal Fatigue

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Awni Qasaimeh ◽  
Sa’d Hamasha ◽  
Younis Jaradat ◽  
Peter Borgesen
Keyword(s):  
Crack Initiation ◽  
Mechanical Response ◽  
Solder Joints ◽  
Fatigue Testing ◽  
Hysteresis Loops ◽  
Damage Function ◽  
Lead Free ◽  
Lead Free Solder ◽  
Sac305 Solder ◽  
Free Solder

The extrapolation and generalization of accelerated test results for lead free solder joints require the identification of a damage function that can be counted on to apply beyond the region of the test. Individual ball grid array (BGA) scale Sn3Ag0.5Cu (SAC305) solder joints were subjected to isothermal shear fatigue testing at room temperature and 65 °C. The resulting mechanical response degradation and crack behavior, including strain hardening, crack initiation, and propagation, were correlated with the inelastic work and effective stiffness derived from load–displacement hysteresis loops. Crack initiation was found to scale with the accumulated work, independently of cycling amplitude and strain rate. The subsequent damage rate varied slightly with amplitude.

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