Review on microstructure evolution in Sn–Ag–Cu solders and its effect on mechanical integrity of solder joints

Sona, Mrunali; Prabhu, K. Narayan

doi:10.1007/s10854-013-1240-0

Cited by 58 publications

(12 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A few common surface finishes are immersion gold over electroless or electrolytic nickel (ENIG), immersion tin (ImSn), immersion silver (ImAg), organic solderability preservative (OSP), and lead-free (SAC or Sn-Cu) hot-air solder leveling (HASL). [8][9][10][11] Choubey et al 11 studied intermetallic growth during solid-state aging at 100°C and 125°C up to 1000 h for Sn-3.5Ag and Sn-3.0Ag-0.5Cu solder alloys on various pad finishes such as ImSn, ImAg, OSP, and ENIG. Sn-3.5Ag solder on ENIG pad finish showed a significantly thinner IMC layer compared with ImSn, ImAg, and OSP pad finishes, whereas comparable IMC thickness was observed for Sn-3.0Ag-0.5Cu solder on various surface finishes.…”

Section: Introductionmentioning

confidence: 99%

Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

Sona

Prabhu

2016

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

The effect of reflow time on wetting behavior of Sn-2.5Ag-0.5Cu lead-free solder on bare and nickel-coated copper substrates has been investigated. The solder alloy was reflowed at 270°C for various reflow times of 10 s, 100 s, 300 s, and 500 s. On bare copper substrate, the intermetallic compound (IMC) thickness increased with increase in reflow time, whereas on Ni-coated Cu substrate, the IMC thickness increased up to 300 s followed by a drop for solder alloy reflowed for 500 s. The spreading behavior of the solder alloy was categorized into capillary, gravity (diffusion), and viscous zones. Gravity zone was obtained from 3.8 ± 0.43 s to 38.97 ± 3.38 s and from 5.99 ± 0.5 s to 77.82 ± 8.84 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. Sn-2.5Ag-0.5Cu solder alloy was also reflowed for the period corresponding to the end of the gravity zone (40 s and 80 s on bare and Nicoated Cu, respectively). The joint strength was maximum at reflow time of 40 s and 80 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. The dynamic contact angle at the end of the gravity (diffusion) zone (h gz ) was found to be a better parameter compared with the stabilized contact angle (h f ) to assess the effect of the wettability of the liquid solder on the microstructure and joint strength. The present investigation reveals the significance of the gravity zone in assessment of optimum reflow time for leadfree solder alloys.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

Sona

Prabhu

2016

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

show abstract

“…Clearly, compared with the von Mises stress, the geometry effect on the plastic strain energy density is more distinct. For example, the maximum plastic strain energy density decreases During reflow soldering, the formation of IMC phases, such as Cu 6 Sn 5 and Ag 3 Sn, between Cu substrate and Sn-Ag-Cu solder is inevitable [31]. In Cu/Sn-Ag-Cu/Cu solder joints, Cu atoms can migrate from Cu substrate (or pad) to the solder matrix, thus coarse and irregular Cu 6 Sn 5 particles are usually formed and they can deteriorate the reliability of solder joints [32].…”

Section: Stress and Strain State In Bga Solder Joints Under Shear Loamentioning

confidence: 99%

Geometry effect on mechanical performance and fracture behavior of micro-scale ball grid array structure Cu/Sn–3.0Ag–0.5Cu/Cu solder joints

Zhang

Zhou

et al. 2015

Microelectronics Reliability

View full text Add to dashboard Cite

“…However, the Ag content of Sn-Ag-Cu solders has attracted much attention over the past few years because it has been shown that low-silver-content Sn-Ag-Cu interconnections perform better under drop loading conditions as compared with near-eutectic Sn-Ag-Cu compositions (see, e.g., Refs. [62][63][64][65][66][67].…”

Section: Effects Of Ag Concentration On Mechanical Properties Of Sn-amentioning

confidence: 99%

The Reliability of Microalloyed Sn-Ag-Cu Solder Interconnections Under Cyclic Thermal and Mechanical Shock Loading

Mattila

Hokka

Paulasto‐Kröckel

2014

Journal of Elec Materi

View full text Add to dashboard Cite

In this study, the performance of three microalloyed Sn-Ag-Cu solder interconnection compositions (Sn-3.1Ag-0.52Cu, Sn-3.0Ag-0.52Cu-0.24Bi, and Sn-1.1Ag-0.52Cu-0.1Ni) was compared under mechanical shock loading (JESD22-B111 standard) and cyclic thermal loading (40 ± 125°C, 42 min cycle) conditions. In the drop tests, the component boards with the low-silver nickel-containing composition (Sn-Ag-Cu-Ni) showed the highest average number of drops-to-failure, while those with the bismuth-containing alloy (Sn-Ag-Cu-Bi) showed the lowest. Results of the thermal cycling tests showed that boards with Sn-Ag-Cu-Bi interconnections performed the best, while those with Sn-Ag-Cu-Ni performed the worst. Sn-Ag-Cu was placed in the middle in both tests. In this paper, we demonstrate that solder strength is an essential reliability factor and that higher strength can be beneficial for thermal cycling reliability but detrimental to drop reliability. We discuss these findings from the perspective of the microstructures and mechanical properties of the three solder interconnection compositions and, based on a comprehensive literature review, investigate how the differences in the solder compositions influence the mechanical properties of the interconnections and discuss how the differences are reflected in the failure mechanisms under both loading conditions.

show abstract

Review on microstructure evolution in Sn–Ag–Cu solders and its effect on mechanical integrity of solder joints

Cited by 58 publications

References 89 publications

Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

Geometry effect on mechanical performance and fracture behavior of micro-scale ball grid array structure Cu/Sn–3.0Ag–0.5Cu/Cu solder joints

The Reliability of Microalloyed Sn-Ag-Cu Solder Interconnections Under Cyclic Thermal and Mechanical Shock Loading

Contact Info

Product

Resources

About