Models for reliability prediction of fine-pitch BGAs and CSPs in shock and drop-impact

Lall, Pradeep; Panchagade, Dhananjay; Liu, Yueli; Johnson, Wayne; Suhling, Jeffrey C.

doi:10.1109/ectc.2004.1320280

Cited by 96 publications

(23 citation statements)

References 3 publications

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“…8). Lall et al [8] also reported PCB resin cracks in the drop test of a 8x8mm chip scale package. As for the PQFP packages where failures were also recorded, they were not due to solder joint crack but component failure instead.…”

Section: Test Resultsmentioning

confidence: 93%

“…From the physics of failure characterized in the drop test, improved solutions to IC package design can be implemented to avoid such drop related failures in service. Research on drop impact testing and finite element modeling investigations [1][2][3][4][5][6][7][8][9][10] are further needed for developing a design-for-reliability (DFR) methodology [5] for drop impact reliability qualification of board-level soldered assemblies. Drop impact responses such as acceleration and strains experienced by the PCB are obtained and studied to investigate the mechanisms of the solder joint failure modes [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Drop Impact Reliability Testing for Lead-Free and Leaded Soldered IC Packages

Chong¹,

Ng²,

Tan³

et al.

Proceedings Electronic Components and Technology, 2005. ECTC '05.

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Portable electronic products such as cellular phones, PDAs, and MP3 units are increasingly designed for accidental drop. Repeated drop events can lead to solder joint failure and malfunction of these products. Hence board-level reliability drop testing is a useful way to characterize the drop durability of the printed circuit board with different soldered assemblies. Lead-free (or Pb-free) solders are replacing lead-based solders. Surface mounted electronic packages are getting smaller and with higher density (I/Os). In this study, Plastic Ball Grid Array (PBGA), Quad Flat No-lead (VQFN) and PQFP solder joint reliability characterization by drop impact testing was investigated for lead-based (62Sn-36Pb-2Ag) and lead-free (Sn-4Ag-0.5Cu) soldered assemblies. The influence of different package types and the impact of PCB surface finishes for OSP and ENIG (electroless nickel immersion gold) were studied. The drop test results showed that leadfree solder joints with ENIG finish have weaker drop reliability performance than the case for OSP surface finish. The different solder alloy-to-surface finish type combination results in different intermetallics formed and contributed to different failure sites and mode of failure.

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Section: Test Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Drop Impact Reliability Testing for Lead-Free and Leaded Soldered IC Packages

Chong¹,

Ng²,

Tan³

et al.

Proceedings Electronic Components and Technology, 2005. ECTC '05.

View full text Add to dashboard Cite

show abstract

“…However, for the PBGA package with OSP finish case, PCB copper traces breakage and resin cracks were the contributing factor for failure [1]. Lall et al [9] also reported PCB resin cracks in the drop test of chip scale package. As for the PQFP packages, failures were not due to solder joint crack but component failure with the lead fingers breaking off from the mold compound due to fatigue of leads.…”

Section: Board Level Drop Test and Analysismentioning

confidence: 95%

Drop Impact Analysis of Sn-Ag-Cu Solder Joints using Dynamic High-Strain Rate Plastic Strain as the Impact Damage Driving Force

Pang

Che

56th Electronic Components and Technology Conference 2006

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Board-level drop reliability test and analysis requires dynamic characterization of high strain-rate properties of bulk solder and solder joint failure tests. Drop impact analysis of board-level dynamic response (ie: G-levels and board bending strains) and over-simplification of deformation response of solder joints (ie: assuming elastic stress criteria) can lead to wrong conclusions in the physics-of-failure understanding in drop impact tests. Solder joint failures during drop testing is a complex failure interaction process between low cycle impact fatigue crack growth versus brittle fracture of the intermetallic interfaces. During a drop test event, dynamic hardening causes the yield stress in the solder to rise several times above the nominal monotonic tensile test yield stress. The increase in dynamic strength in the solder joint can cause dynamic strain cycling in the solder material and lead to progressive low cycle impact drop fatigue failures. On the other hand, when the drop loading is excessive, impact failure strength of the intermetallic interface will result in brittle fracture of the solder joint. Impact test were conducted with a Split Hopkinson pressure bar (SHPB) test system to study the dynamic response of bulk solder materials and impact failure of solder joint interfaces.Solder joint reliability characterization by drop impact test with clamped-clamped boundary condition were investigated for PBGA assembly with Sn-Ag-Cu solder. FEA modeling and simulation of drop impact were conducted considering different solder constitutive models such as elastic and strain rate dependent plastic model to investigate the effect of solder constitutive model on dynamic response in the solder joint. The important finding of this study is that the constitutive model used has a major impact on dynamic response of solder joint stress and strain results. It was expected that strain rate dependent plastic model gave better correlation results than the simple elastic model. This study also investigates the IMC effect on solder strain response subject to drop impact test simulation.

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“…As explained earlier, existing damage models in literature [3][4][5][6][7][8][9][10][11] do not address the rate-dependence of durability, for dynamic loading of PWAs. We propose a new mechanistic, rate-dependent durability estimation model in this paper that focuses on solder failure.…”

Section: Damage Modelmentioning

confidence: 99%

“…Empirical models have been developed to quantify durability as a function of PWA strain [3][4][5] and PWA displacement [6]. In some cases, Finite Element Analysis (FEA) with rate-independent material properties has been used to quantify durability in terms of solder stress [7][8][9] or solder strain [10,11] and to develop failure envelopes based on normal and shear forces in the solder [12].…”

Section: Introduction and Problem Statementmentioning

confidence: 99%