Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

Lee, Liu Mei; Mohamad, Ahmad Azmin

doi:10.1155/2013/123697

Cited by 56 publications

(32 citation statements)

References 60 publications

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“…In addition, the formation of large plate like Ag 3 Sn IMCs causes solid dissolution and precipitation hardening, which in turn decreases the matrix strength [54,55]. The overall reliability of the solder joint can be greatly affected by the amount and size of Ag 3 Sn IMCs in the microstructure [56]. Since the Cu content in the SAC-305 alloy is very small, the majority of the IMCs formed in SAC305 are Ag3Sn particles.…”

Section: Introductionmentioning

confidence: 99%

Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy

Yasmin¹,

Sadiq²,

Khan³

2013

J Material Sci Eng

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Citation: Yasmin T, Sadiq M, Khan MI (2014) Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy. J Material Sci Eng 3: 141. SAC305Among the various lead-free solders SAC-305 alloy has emerged as the most widely accepted to replace Sn-Pb solders. It is widely used as lead-free solder for surface mount technology (SMT) card assembly and for ball-grid-array (BGA) interconnection in the microelectronic packaging industry as solder balls and pastes. More than 70% market for reflowing lead-free solders are in the SAC series. Due to having good mechanical properties, acceptable wetting properties, and suitable melting points, the International Printed Circuit Association has suggested that SAC-305 and SAC-396 will be the most widely used alloys in the future [10][11][12][13][14][15][16].Although SAC-305 alloy is widely used in electronics industry, it has several problems to be solved. One of the core issues pertaining to Abstract Sn96.5Ag3Cu0.5 (SAC305) is widely used as lead-free solder for surface mount technology (SMT) card assembly and for ball-grid-array (BGA) interconnection in the microelectronic packaging industry as solder balls and pastes. In this study the effects of Lanthanum (La) doping on SAC305 under thermal aging was investigated as function of intermetallic compounds (IMCs) growth and grain size evolution. The morphology of the microstructure was analyzed under Scanning Electron Microscope (SEM) and optical microscope, the elemental distribution was confirmed by Energy Dispersive Spectroscopy (EDS) and phase identification of the crystalline structure formed during thermal aging was confirmed by x-ray diffraction (XRD). It was found that the microstructure of SAC305 solder alloy changes significantly with addition of La. Quantitative analysis of grain size and intermetallic particle size was performed both for undoped and La-doped SAC305 alloys.The XRD and EDS tests found that the doping elements La exist in SAC305 solder alloy in two forms: as La element or as La5Sn3 IMC.The La-Sn IMC has complex branch structure [89], which is usually look like clusters of snowflakes [57] in SEM images. With the help of EDX analysis very high amount of La concentration of observed in these snowflakes. Moreover It was also observed that quantity La5Sn3 IMC depend upon the concentration La doping i.e. with high 0.5wt% of lanthanum bigger snowflakes has be observed as shown in Figure 8 while small isolated snow can be seen with less La doping which is consistent with the results of Min et al [25].La doping greatly reduces the Ag 3 Sn and Cu 6 Sn 5 particle size particle during thermal aging. Surface area averaged particle size of Cu 6 Sn 5 particles was obtained as per ASM handbook [95]. The particle sizes for the full data set are plotted in Figure 9 as function of La doping level. It can be seen that La doping effectively suppresses the growth of Ag 3 Sn and Cu 6 Sn 5 intermetallic particle.

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Section: Introductionmentioning

confidence: 99%

Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy

Yasmin¹,

Sadiq²,

Khan³

2013

J Material Sci Eng

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“…Further, the results of microstructural examination using SEM on extruded CSES and CSI solder joints revealed no cracks or debonding at the interface which means the interfacial integrity was good (see Figures 13 and 15 bonding between the substrate and solder mostly depends on the integrity of the intermetallic compound (IMC) layer. e long-term reliability of solder joints depends on how, at the interface, IMCs are formed as reaction products between the solder and the substrate during soldering [38][39][40][41][42]. In this study, IMCs were clearly observed in Cu/ SAC305/Cu solder joints (see Figures 13(a) Figures 13(a), 13(c), 13(e), 13(g), 13(i), 13(k), 13(m), and 13(o)) had slightly less thickness than CSI (before and after corrosion) solder joints (see Figures 13(b), 13(d), 13(f ), 13(h), 13(j), 13(l), 13(n), and 13(p), which reduced the brittleness in CSES joints thus making CSES solder joints marginally better in strength than CSI solder joints.…”

Section: Microstructural Characterization Figures 12 and 13mentioning

confidence: 99%

Microstructure, Mechanical, and Electrical Properties and Corrosion Analysis of Lead‐Free Solder CSI Joints on Cu Substrate Using Novel Concentrated Solar Energy Soldering (CSES) Method

Sonawane

Raja

Gupta

2020

Advances in Materials Science and Engineering

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In this study, “Concentrated Solar Energy (CSE)” is applied for soldering and is named as the “Concentrated Solar Energy Soldering (CSES) technique.” Lead-free solders are used for comparing novel CSES technique solder joints with CSI (Conventional Soldering Iron) solder joints. Tensile strength, bending/flexural strength, microhardness, electrical resistivity, fractography, optical microstructures, SEM microstructures, and EDS analysis were used to compare CSES solder joints with CSI solder joints. The salt spray test (SST) was used for corrosion analysis of CSES and CSI solder joints. Experimental results reveal that the tensile response, bending strength, and microhardness of the CSES solder joints were almost equal to those of the CSI solder joints. It was observed that after corrosion, the tensile strength, bending strength, and microhardness for CSES and CSI solder joints reduced. CSES solder joints were found to be slightly better than CSI solder joints for electrical resistivity. Electrical resistivity for all the cases studied was found to increase slightly after corrosion. Interfacial integrity and effect of corrosion were clearly observed on CSES and CSI solder joint microstructures. The intermetallic compounds (IMC) formed in case of CSES solder joints were found to be having slightly less thickness than that of CSI solder joints. The results demonstrate CSES technique as a green technology and a potential substitute to the CSI method.

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“…Thick IMC negatively affect the long-term reliability of solder joints due to their brittle nature [4,5].…”

Section: Jointsmentioning

confidence: 99%

Introductory Chapter: Overview of Recent Progress in Soldering Materials

Mohamad¹

2017

Recent Progress in Soldering Materials

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Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

Cited by 56 publications

References 60 publications

Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy

Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy

Microstructure, Mechanical, and Electrical Properties and Corrosion Analysis of Lead‐Free Solder CSI Joints on Cu Substrate Using Novel Concentrated Solar Energy Soldering (CSES) Method

Introductory Chapter: Overview of Recent Progress in Soldering Materials

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