Effect of reflow and thermal aging on the microstructure and microhardness of Sn-3.7Ag-xBi solder alloys

He, Min; Acoff, Viola L.

doi:10.1007/s11664-006-0319-2

Cited by 25 publications

(14 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was also already shown that bismuth and silver can have a significant impact on the corrosion properties in case of Sn-based solder alloy in NaCl solutions [17,18]. Furthermore, the influence of bismuth addition on the microstructure and the properties of Sn-rich SnAg lead-free solders has been also widely studied [13,[19][20][21][22][23]. However, the effect of bismuth on the corrosion behaviour in the case of micro-alloyed solder alloy is not deeply addressed in the literature.…”

Section: Discussionmentioning

confidence: 99%

Effect of Bismuth and Silver on the Corrosion Behavior of Lead-free Solders in 3.5 wt% NaCl Solution

Tamasi

Kosa

Szabó

et al. 2016

Period. Polytech. Elec. Eng. Comp. Sci.

View full text Add to dashboard Cite

IntroductionOne of the key reliability issues of the electronics technology is carry about the solder joints testing. Usually, the different failures can lead back to the not adequate physical properties (e.g. wetting behaviour, mechanical strength, etc.) of the solder alloy and/or the not adequate applied technological processes (e.g. reflow temperature profile), which have to be improved. This challenge was updated in 2006, with the introduction of lead-free solder alloys governed by the RoHS directive of EU [1]. Due to the lead-free limitations, different solder types such as near-eutectic Tin-Silver, Tin-Copper, and Tin-Zinc alloys were produced as replacement for Tin-Lead solder materials. Furthermore, solders with more alloying elements, such as (Tin-Silver-Copper, Tin-Zinc-Silver, Tin-Zinc-Indium) and/or (Tin-Zinc-Silver-Aluminum, Tin-Silver-Bismuth-Copper, TinIndium-Silver-Antimony) were also investigated as replacements for Pb-free types [2]. While, the different qualifying studies of the Pb-free solder alloys are even active topics [3] and one of the issues is carry about humidity induced failures, like electrochemical corrosion [4,5]. Different results were also published related to novel Pb-free solder alloys in terms of reliability topics, such as solderability [6], intermetallic layer (IML) investigation [7], shear force tests [8], wetting investigations [9] or (solid state physics) migration tests [10]. On the other hand, the investigations of humidity induced failures (like corrosion) of Pb-free solder alloys are not deeply addressed in the scientific publications. In our former publication [11], various microalloyed Pb-free solders tested in terms of corrosion resistance using electroanalytical tests. In that study [11] different Pb-free solder alloys (four micro-alloyed and a Sn96.5Ag3Cu0.5 alloy as reference) were compared using potentiodynamic polarisation tests. During polarisation tests, the sample (working electrode) is scanned from a cathodic polarisation state, and after reaching the corrosion potential (Ecorr) it begins anodic polarisation. When the sample reaches the passivation potential, if possible a passivation film begins to form on the surface and the current density at this point is called the critical current density (Icrit). After this point the corrosion current density begins to drop to a much lower value. When a compact passivation film

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of Bismuth and Silver on the Corrosion Behavior of Lead-free Solders in 3.5 wt% NaCl Solution

Tamasi

Kosa

Szabó

et al. 2016

Period. Polytech. Elec. Eng. Comp. Sci.

View full text Add to dashboard Cite

show abstract

“…The addition of bismuth to Sn-Ag alloys is believed to reduce the melting temperature, but wetting behavior and mechanical strength are degraded as well. [5][6][7] A certain amount of indium alloyed into Sn-Ag-Bi solder systems could decrease the melting point, and also improves the mechanical strength and the wetting ability. The compositions of the solders used in this study are 84Sn-3Ag-3Bi-10In and 89Sn-3Ag-3Bi-5In (in weight percent, and represented by 84-3-3-10 and 89-3-3-5 hereafter).…”

Section: Introductionmentioning

confidence: 99%

The Effects of Solid-State Aging on the Intermetallic Compounds of Sn-Ag-Bi-In Solders on Cu Substrates

Chen

Siao

2008

Journal of Elec Materi

View full text Add to dashboard Cite

The growth behavior of the intermetallic compounds that formed at the interfaces between Sn-Ag-Bi-In solders and Cu substrates during solid-state aging is investigated. The compositions of the intermetallic compounds are Cu 3 (Sn,In) near the Cu substrates and Cu 6 (Sn,In) 5 near the solders; very little Bi or Ag was dissolved in the compounds. The aging temperatures were 120°C, 150°C, and 180°C for 5 days, 10 days, 20 days, and 40 days. The change in the morphology of Cu 6 (Sn,In) 5 from scallop type to layer type was prominent at the aging temperature of 180°C. The thickness of the compound layers did not vary much at the lower aging temperatures but followed the diffusioncontrolled mechanism at 180°C. Massive Kirkendall voids were observed in Cu 3 (Sn,In) layers at the aging temperature of 180°C.

show abstract

“…[7][8][9][10][11][12][13][14][15][16] Bismuth has been reported as one type of addition to lower the melting temperature, increase the wettability, and improve the mechanical properties of solder alloys. [7][8][9][10][11][12][13][15][16][17] Our previous work reported that, with the addition of Bi into Sn-3.7Ag solders, the melting temperature decreased and the microhardness of Sn-Ag-xBi solders increased because Bi formed a solid solution with Sn and also Bi particles precipitated during the cooling process. 16 However, there is still a lack of knowledge about the effect of Bi on the interfacial reaction between leadfree solders and the Cu substrate, especially the relationship between the interfacial intermetallic compound (IMC) growth kinetics and the amount of Bi addition into the solders.…”

Section: Introductionmentioning

confidence: 99%

Effect of Bi on the Interfacial Reaction between Sn-3.7Ag-xBi Solders and Cu

Acoff

2007

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

It was reported in previous studies that the addition of Bi could improve the wettability and reduce the melting temperature of Sn-Ag solders. This work investigates the effect of Bi on the interfacial reaction between Sn-Ag-xBi solders and the Cu substrate reflowed at 250°C for different times and thermally aged at 150°C for different durations. Five types of Sn-Ag-based solders, Sn-3.7Ag-xBi (x = 0 wt.% to 4 wt.%), were used in this study. The microstructure of the interfacial Cu-Sn intermetallic compound (IMC) layers between the solders and the Cu substrate was studied, and the thickness of the Cu-Sn IMCs in different solder/Cu systems has been measured. It was found that the thickness of the Cu-Sn IMC layer decreased with increasing amount of Bi in both the reflow and thermally aged condition. The effect of Bi addition on the interfacial reaction between the solder and the Cu substrate was discussed based on the experimental results.

show abstract

Effect of reflow and thermal aging on the microstructure and microhardness of Sn-3.7Ag-xBi solder alloys

Cited by 25 publications

References 17 publications

Effect of Bismuth and Silver on the Corrosion Behavior of Lead-free Solders in 3.5 wt% NaCl Solution

Effect of Bismuth and Silver on the Corrosion Behavior of Lead-free Solders in 3.5 wt% NaCl Solution

The Effects of Solid-State Aging on the Intermetallic Compounds of Sn-Ag-Bi-In Solders on Cu Substrates

Effect of Bi on the Interfacial Reaction between Sn-3.7Ag-xBi Solders and Cu

Contact Info

Product

Resources

About