Dynamic Crack Propagation Prediction of Solder Joints under Impact Conditions

Towashiraporn, P.; Crosbie, P.; Brown, Matthew; Cavallaro, Antonio

doi:10.1109/ectc.2007.373871

Cited by 6 publications

(4 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the detailed solder joint model to predict damage progression of solder joints in drop/impact environment [7,8] can accurately capture rate dependent effects and plasticity in the material without the limitations inherent in global-local or submodel modeling techniques [7,12]. The detailed model of solder joints can, however, substantially increase the size of the finite element model especially in a complex system wherein multiple area-array packages are used.…”

Section: Finite Element Modelingmentioning

confidence: 99%

“…The use of finite element analysis during the design stage can reduce the number of required structural tests which often are expensive, time-consuming, and destructive. Towashiraporn et al [7,8] demonstrated that through theory of fracture mechanics, the crack propagation model based on traction-separation law framework can be used to accurately predict intermetallic failure of solder joints subjected to drop/impact loading conditions. Although the methodology is capable of predicting accurate crack shape and extent of damage progression, it comes with a penalty on computational time which ultimately can be a critical factor during the development stage in the fiercely competitive business of mobile device manufacturing.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of pcb flexural modes on dynamic reliability of ball grid array packages

Towashiraporn

Crosbie

Lee

2008

2008 58th Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

To enable richer consumer experiences, more IC chipsets with various functionalities and greater memory density have been deployed in the limited phone board area. A new generation of surface mount devices such as fine pitch BGA, package-on-package (POP), and wafer-level packaging, are being introduced to reduce board area for the given feature set. Board level reliability of new packages is one of the most important aspects to system performance under impact loadings. The dynamic reliability characterization of the components has been used as a basis for predicting a system (phone) level reliability. Package characterization methodologies must be designed to capture the interconnect failure modes of the actual IC packages commonly encountered in phone drop conditions for better prediction of phone-level reliability.Strain gage measurements and finite element analysis (FEA) of drop tests performed on portable electronic devices revealed mixed printed circuit board (PCB) flexural modes during impact. Dynamic planar and spherical bend tests were developed to study the effect of PCB bend mode on solder interconnect reliability. In the present study, a planar flexural mode was generated through utilization of a 4-point bend test fixture, and a spherical bend test was developed to achieve an equi-biaxial strain state at the vicinity of a corner solder joint as opposed to predominantly uni-directional strain state in four-point bend test. A failure prediction model based on connector finite element modeling was developed to understand the significantly different solder joint reliability under the two loading conditions. The ability of the new modeling technique to accurately predict failure of solder joints under different loading conditions was appreciated showing excellent agreement to failure analysis of actual test samples. The new methodology can enable efficient and accurate means of assessing package reliability under various conditions that simulate portable electronic devices being dropped in the field. IntroductionWith increasing awareness of the ability for electronic packages to sustain a certain amount of drop/impact loading in the field, strain-based quantity is increasingly being used during component qualification. The component has to meet strain-based requirement that can be induced by qualified drop tests. As metrologies for dynamic bend testing are proliferating quickly, it is important that testing methodologies are able to capture the loading conditions which the package is to be subjected to in the field in order to provide meaningful data for an evaluation of the allowable strain for the component. A number of studies [1, 2] were conducted to evaluate the effect of package orientation with

show abstract

Section: Finite Element Modelingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of pcb flexural modes on dynamic reliability of ball grid array packages

Towashiraporn

Crosbie

Lee

2008

2008 58th Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

show abstract

“…Dynamic loading was generated in the test vehicle through four-point bend test setup similar to the those reported earlier [2,4,5]. In this setup the test vehicle was centered in a fourpoint bend fixture and a known impact weight was dropped on to the top span fixture from different heights to control the stress and strain levels subjected to the test boards.…”

Section: Experimental Details Impact Bend Testmentioning

confidence: 99%

“…Therefore, it becomes important to select suitable solder materials that survive these conditions. Solder joint formation is basically a reaction between the bulk solder and the pad materials leading to the formation of intermetallic compounds such as Cu 6 Sn 5 and Cu 3 Sn for TinSilver-Copper (SAC) solder alloy and copper pad [2] or Ni 3 Sn 4 etc. between Sn base solder and NiAu pads.…”

Section: Introductionmentioning

confidence: 99%

Reliability of mixed alloy ball grid arrays using impact bend test and drop shock test

Pandher¹,

Pachamuthu²,

Raut³

2011

2011 IEEE 61st Electronic Components and Technology Conference (ECTC)

View full text Add to dashboard Cite

Low-silver SnAgCu alloys are quickly becoming the standard Pb-free solders for portable electronic devices. However, the industry's quick adoption of near-eutectic SnAgCu alloys (SAC305 and SAC405, so called high-Ag Alloys) and its resistance to the adopted process change entails unavoidable situations where the components have a high-Ag SAC alloy while the paste used to assemble these components on the boards has a low-Ag alloy or vice versa. The impact of such mixed alloy assemblies has been and continues to be the subject of many recent studies.In this study, the mechanical reliability of printed circuit boards with a number of Pb-free BGA components assembled using two different Pb-free solder pastes (SACX and SAC105) has been studied using the Dynamic Four Point Bend Test (also called Impact Bend Test) and the Drop Shock Test. In the impact bend test, these boards were subjected to different mechanical shocks resulting in different strains. Results were plotted as the percentage of failed solder joints as a function of the strain experienced at the board and fitted to a Weibull distribution to estimate the usable life of the assembly in such circumstances. The drop shock test was conducted per JEDEC standard JESD22-B111 according to which the boards are subjected to the same mechanical shock repeatedly, and the failure fraction data was plotted as a function of the number of drops. The combinations of the BGA solder sphere alloy and the paste alloy used in the drop shock tests were exactly the same as those used in the Impact Bend Test.Results of both impact bend and drop shock tests show very good correlation. Analysis of the failed samples was done with the Dye and Pry test to identify whether the failure was on the board side or on the component side. Failure analysis of the impact bend test samples showed a slight difference in the distribution of failures on the component side and those on the board side. In drop shock test, most of the solder joints failed on the component side. Results show that even in the situations where the quantity of the solder coming from the solder paste was small relative to the quantity contributed by the sphere, the impact of the paste alloy was significant. An attempt was made to explain the observations in terms of solder inter-diffusion kinetics and resulting micro-structural changes. IntroductionIt is estimated that more than ten trillion solder joints are made annually in the electronics industries for various applications (e.g., mobile, aerospace, etc.). Solder joint is the interconnect technology that provides electrical continuity and mechanical integrity between the pad and component in the electronics assemblies [1]. With the recent trend towards

show abstract

Drop impact reliability of Sn–1.0Ag–0.5Cu BGA interconnects with different mounting methods

Wang

Gallagher

et al. 2012

Microelectronics Reliability

View full text Add to dashboard Cite

Dynamic Crack Propagation Prediction of Solder Joints under Impact Conditions

Cited by 6 publications

References 7 publications

The effect of pcb flexural modes on dynamic reliability of ball grid array packages

The effect of pcb flexural modes on dynamic reliability of ball grid array packages

Reliability of mixed alloy ball grid arrays using impact bend test and drop shock test

Drop impact reliability of Sn–1.0Ag–0.5Cu BGA interconnects with different mounting methods

Contact Info

Product

Resources

About