Use-condition-based cyclic bend test development for handheld components

Mercado, L.L.; Phillips, B.; Sahasrabudhe, S.; Sedillo, J.P.; Bray, D.; Monroe, Eric M.; Lee, Kang Joon; Lo, George

doi:10.1109/ectc.2004.1320278

Cited by 23 publications

(11 citation statements)

References 4 publications

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“…And the cyclic bending test also was started, because the use of mobile device has been increased. As a result of previous study, thermal cycling behavior of solder joints was revealed brightly [1][2][3][4] and bending fatigue behavior has been uncovered [5][6][7]. But the relationship between thermal and bending fatigue behavior was not discovered yet.…”

Section: Introductionmentioning

confidence: 87%

Fatigue Life Evaluation of Lead-free Solder under Thermal and Mechanical Loads

Kim

Lee

2007

2007 Proceedings 57th Electronic Components and Technology Conference

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In this study, two types of fatigue tests were conducted. First, cyclic bending tests were performed using the microbending tester. A four-point bending test method was adopted, because it induces uniform stress fields within a loading span. Second, thermal fatigue tests were conducted using a pseudo power cycling machine which was newly developed for a realistic testing condition. The pseudo-power cycling method makes up for the weak points in a power cycling and a chamber cycling method. Two compositions of solder are tested in all test condition, one is lead-free solder (95.5Sn4.OAgO.5Cu) and the other is eutectic lead-contained solder (63Sn37Pb).In the cyclic bending test, the solder that exhibits a good reliability can be reversed depending on the load conditions. The lead-contained solders have a longer fatigue life in the region where the applied load is high. On the contrary, the lead-free solder sustained more cyclic loads in the small load region. A similar trend was detected at the thermal cycling test. Furthermore, to certify the crack behavior, the failed specimen was sectioned. In thermal cycling case, crack initiated inner solder joints. But outmost solder failed first in the cyclic bending test.A three-dimensional finite element analysis model was constructed. A finite element analysis using ABAQUS was performed to extract the applied stress and strain in the solder joints. A constitutive model which includes both creep and plasticity was employed. Thermal fatigue was occurred due to the creep. And plastic deformation is main damage for bending failure. From the inelastic energy dissipation per cycle versus fatigue life curve, it can be found that the bending fatigue life is longer than the thermal fatigue life.

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Section: Introductionmentioning

confidence: 87%

Fatigue Life Evaluation of Lead-free Solder under Thermal and Mechanical Loads

Kim

Lee

2007

2007 Proceedings 57th Electronic Components and Technology Conference

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“…Four-point bending test is widely used because it is suitable for testing large sample size of packages at similar loading condition (bending moments) between the inner load span regions. All the existing bend tests from reported literature [3][4][5] were conducted at room temperature (25 o C) and were for tin-lead (Sn-Pb) solder joints. Typical thermal cycling reliability test from -40 o C to 125 o C was commonly used in industries and research areas to investigate the thermal fatigue reliability for soldered electronic assembly.…”

Section: Introductionmentioning

confidence: 99%

Cyclic bend fatigue reliability investigation for Sn-Ag-Cu solder joints

Che¹,

Pang

Zhu³

et al. 2006

2006 8th Electronics Packaging Technology Conference

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In this study, VQFN assembly and FBGA assembly with Sn-3.8Ag-0.7Cu lead-free solder and OSP board surface finish were tested under four-point cyclic bending load at high temperature (125 o C). Experimental results shows that the FBGA component has higher bending fatigue resistance compared to VQFN component at the same bending condition. Failure mode analysis shows that the dominant failure is solder joint fatigue cracking failure for both assemblies. FEA modeling and simulation were performed to investigate the stress-strain behavior of solder joint. Energy-based bending fatigue model has been developed based on experimental data and FEA results for VQFN assembly under high temperature bending condition. Bend fatigue model proposed in this paper for VQFN assembly was compared to energy-based fatigue model derived from bulk solder fatigue test. Bending fatigue model from VQFN specimen results in significant difference in predicting bending fatigue for FBGA assembly compared to experimental result. However, the fatigue model from bulk solder fatigue test is suitable for prediction of FBGA bending fatigue life.

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“…The support span of 100mm and load span of 70mm (see Fig. 1 So far, reported bend tests from the literature [1][2][3][4] were conducted at room temperature (25 o C) and there is lack of 1-4244-0152-6/06/$20.00 ©2006 IEEE data for lead-free solder joints. In this study, four-point cyclic bend tests with frequency of 1Hz were conducted for leadfree specimen at room temperature and high temperature of 125 o C to investigate high temperature effect on bending fatigue failure.…”

Section: Cyclic Bend Test and Analysismentioning

confidence: 98%

“…Skipor and Leicht [8] developed a bending fatigue model for PBGA SnPb solder joint using inelastic strain as damage parameter. Mercado et al [3] proposed a total energy-based bending fatigue model for CSP with eutectic SnPb solder. All bending fatigue models were developed at room temperature from literatures.…”

Section: Bending Fatigue Model Development For Sac Soldermentioning

confidence: 99%

“…All the existing bend tests from reported literature [1][2][3][4] were conducted at room temperature (25 o C) and were for tin-lead (Sn-Pb) solder joints. In this study, VQFN and with Sn-Ag-Cu lead-free solder and OSP board surface finish was tested using four-point cyclic bending load at room temperature (25 o C) and high temperature (125 o C).…”

Section: Introductionmentioning

confidence: 99%

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Modeling Board-Level Four-Point Bend Fatigue and Impact Drop Tests

Pang

56th Electronic Components and Technology Conference 2006

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In this paper modeling and simulation of board-level fourpoint bend fatigue and impact tests were investigated for 7mm×7mm VQFN(48I/O) assembly and 15mm×15mm FBGA(324I/O) assembly with Sn-Ag-Cu lead-free solder and OSP board surface finish. For cyclic bending fatigue, fourpoint bend cyclic loading at room temperature (25 o C) and at high temperature (125 o C) were investigated in order to develop bend fatigue model for Pb-free solder. The acceleration factor of failure at high temperature (125 o C) to room temperature (25 o C) will be presented. Test results show that the cycle to failure increases significantly when bending displacement ranges decrease for both bend tests at 25 o C and 125 o C. The acceleration factor of cycle to failure due to high temperature (125 o C) effect is higher than that due to room temperature effect. The FBGA component has higher bending fatigue resistance compared to VQFN component. Accumulated energy density per cycle at 125 o C is more than that at 25 o C significantly, which indicates that higher temperature accelerates bending fatigue failure of solder. Energy-based bending fatigue models were developed for SnAg-Cu lead free solder subjected to cyclic bending load at 25 o C and 125 o C based on FEA result and experimental data. Using the same FEA model the loading was changed to simulate a four-point bend impact test with the same corresponding magnitude of bending curvatures. Comparisons of solder joint deformation response between the slow cyclic bend test and impact drop bend test will be presented.

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Use-condition-based cyclic bend test development for handheld components

Cited by 23 publications

References 4 publications

Fatigue Life Evaluation of Lead-free Solder under Thermal and Mechanical Loads

Fatigue Life Evaluation of Lead-free Solder under Thermal and Mechanical Loads

Cyclic bend fatigue reliability investigation for Sn-Ag-Cu solder joints

Modeling Board-Level Four-Point Bend Fatigue and Impact Drop Tests

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