Fatigue and Bridging Study of High-Aspect-Ratio Multicopper-Column Flip-Chip Interconnects Through Solder Joint Shape Modeling

Liao, E.B.; Tay, A.A.O.; Ang, Simon S.; Feng, Han; Nagarajan, Rajamani; Kripesh, V.

doi:10.1109/tcapt.2006.880509

Cited by 10 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4] In such case, the intermetallic compounds (IMCs) that are usually formed between the pad metallization and solders exert a significant effect on the mechanical integrity of the entire joints. Their growth and evolution throughout the serving can also affect the failure modes and damage mechanism of such micro-scale interconnects, though the IMCs may not be considerably large in the beginning.…”

Section: Introductionmentioning

confidence: 99%

Influence of IMCs volume ratio in micro-scale solder joints on their mechanical integrity

Chen

et al. 2012

2012 IEEE 62nd Electronic Components and Technology Conference

View full text Add to dashboard Cite

Since miniaturization of electronic devices makes the joint height of solder joints shrink to tens of microns. IMCs take noticeably high volume ratio in solder joints, which seldom happens in BGA or bulk solder joints. Growth of IMCs volume ratio will definitely affect mechanical integrities of micro-scale solder joints, which is rarely covered in pervious publications. In this paper, copper/SAC305/copper solder joints with a joint height of 20µm were utilized as specimens. They were aged at 150℃ for different durations to obtain different thickness of IMCs. Microstructure of specimens was studied before tensile tests. The growth of IMCs and aging time follows parabolic law, similar to reported results. Tensile tests were carried out to investigate the effect of IMCs volume ratio on tensile strength and fracture mode. Fracture surface of some selected specimens after tests was observed to determine their dominant fracture modes. When specimens were aged for 1 hour, a significant decrease in tensile strength was observed which is due to the Ag 3 Sn particles locating along grain boundaries and results in intergranular fracture. The tensile strength reaches a peak, 86.1MPa, at 9 hours with the IMCs volume ratio of 21.95%. When the aging process lasted for 16 hours and IMCs volume ratio increased to 23.35%, this is a transition point of fracture mode from ductile to brittle fracture with a difference of tensile strength exceeding 20MPa. As the aging duration continued increasing, the tensile strength falls continuously due to the coarsening of grains with the brittle fracture area being extended.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of IMCs volume ratio in micro-scale solder joints on their mechanical integrity

Chen

et al. 2012

2012 IEEE 62nd Electronic Components and Technology Conference

View full text Add to dashboard Cite

show abstract

“…For decades, this has been highly challenged due to the continuous demands to achieve lower cost but increased functions and miniaturization. [1,2] In numerous cases, the serving conditions for solder interconnects become even more severe, especially in some applications where the electronic devices need to undergo extreme thermal and mechanical loadings in various industrial sectors including space, aerospace and automotive applications.…”

Section: Introductionmentioning

confidence: 99%

An investigation of the influence of intermetallic compounds on compressivecreep of SAC305/copper solder joints by modeling

Chen

et al. 2011

2011 International Symposium on Advanced Packaging Materials (APM)

View full text Add to dashboard Cite

The compressive creep deformation of SAC305/copper solder joints is tested at 12.739MPa and different temperatures ranging from 343K to 463K. The experimental results were analyzedby curve fitting with time hardening model incorporated in Abaqus TM .The influence of intermetallic compounds on compressive creep deformation was also studied by modeling with the parameters of time hardening model which were derived from curve fitting.The modeling results show that deformability of the solders descends sharply at all temperatures, from 343K to 463K, as the volume ratio of intermetallic compounds layer increases. But the distribution of deformation is much more homogeneous, and the deformability of solders becomes similar at different temperatures when the ratio of IMCs is relatively higher.

show abstract

“…For example, the hourglass shape of solder joints made by stacked bumping technology, which includes a high‐melting point solid solder ball inside, improves the fatigue lifetime by about 60 percent over the conventional barrel‐shaped solder joints (Liu and Lu, 2003; Liu et al , 2001). Several other approaches have also been employed to control the joint shapes by the double‐bump technology (Yeung and Lee, 2003) or by using single copper bases (Kawahara, 2000), multi‐copper columns (Liao et al , 2006) or ceramic columns (Bor and Ray, 2000) in the joints. Unfortunately, these technologies are either complex to implement, or have high cost.…”

Section: Introductionmentioning

confidence: 99%

Local melt process of solder bumping by induction heating reflow

Xü

et al. 2009

Soldering &Amp; Surface Mount Technology

View full text Add to dashboard Cite

PurposeThe purpose of this paper is to describe a local melt process of solder bumping employed in electronic packaging applications by an induction heating reflow method, for a combined numerical and experimental study involving a temperature measurement using an infrared thermometer during the reflow process and microstructural observations after reflow, which can be used to control the height and shape of solder interconnects.Design/methodology/approachIn the induction heating reflow process, the temperature distribution within the solder ball during the heating phase is of prime importance for the success of the process and the geometry control quality of final joints. This paper investigates the local melt process of solder balls reflowed onto Cu/Ni/Au pads, and focuses on the effect of the inductive heat on the thermal distribution during the melting process. A finite‐element model is applied to simulate the thermal field in a solder bump during the induction heating period in a reflow process. The effects of the coil current and the electromagnetic frequency on the thermal performance are investigated by using the validated thermal model. The local melt phenomenon in the solder joint is observed and identified by the microstructures taken using scanning electron microscopy.FindingsIn this paper, the numerical results match the experimental results quite well to validate the finite element modeling model. The local melt phenomenon predicted by simulation, and verified by experiments, is demonstrated to be capable of controlling the solder joint shape. Several parametric studies are carried out to understand the effects of different frequencies during assembly, and to suggest that a higher frequency is easier to get a greater temperature gradient, thus a more obvious local melt phenomenon, which is good for achieving the geometry control for solder joints.Originality/valueThe findings of this paper will help to understand the detailed solder bumping process during induction heating reflow and the effects of electromagnetic field frequency on solder joint shape controlling.

show abstract

Fatigue and Bridging Study of High-Aspect-Ratio Multicopper-Column Flip-Chip Interconnects Through Solder Joint Shape Modeling

Cited by 10 publications

References 18 publications

Influence of IMCs volume ratio in micro-scale solder joints on their mechanical integrity

Influence of IMCs volume ratio in micro-scale solder joints on their mechanical integrity

An investigation of the influence of intermetallic compounds on compressivecreep of SAC305/copper solder joints by modeling

Local melt process of solder bumping by induction heating reflow

Contact Info

Product

Resources

About