Effects of reflow atmosphere and flux on Sn whisker growth of Sn–Ag–Cu solders

Baated, Alongheng; Kim, Keun Soo; Suganuma, Katsuaki; Huang, Sharon; Jurcik, B.; Nozawa, S.; Ueshima, Minoru

doi:10.1007/s10854-010-0099-6

Cited by 20 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Work conducted by Baated et al [6] showed the affect of reflow atmosphere and flux activity on tin whisker growth. Evaluations were conducted with pure-tin-coated Cu and Alloy 42 QFP lead-frame components soldered with Sn3Ag0.5Cu solder paste.…”

Section: Influence Of Reflow Atmosphere and Flux On Tin Whisker Growthmentioning

confidence: 99%

Board Reflow Processes and their Effect on Tin Whisker Growth

Bath¹,

Kato²,

Handwerker³

2016

Mitigating Tin Whisker Risks

View full text Add to dashboard Cite

Section: Influence Of Reflow Atmosphere and Flux On Tin Whisker Growthmentioning

confidence: 99%

Board Reflow Processes and their Effect on Tin Whisker Growth

Bath¹,

Kato²,

Handwerker³

2016

Mitigating Tin Whisker Risks

View full text Add to dashboard Cite

“…In high-humidity conditions, 85°C has been shown to promote whisker growth in lead-free solder alloys. [12][13][14] The two isothermal high-humidity environments employed were 25°C/85% RH (3 years) and 85°C/85% RH (4,000 h). The PCTC cycle was +50°C to 85°C with 15-min ramps and dwells in air simulating the conditions in Ref.…”

Section: Experimental Environments and Testingmentioning

confidence: 99%

“…Recent observations have demonstrated the ability of Pb-free solder joints to grow whiskers. 13,14 One challenge accompanying real electronic systems is the interplay among the component design and materials, manufacturing process, and service environments that contribute directly or conspire with one another to exacerbate whisker growth.…”

Section: Introductionmentioning

confidence: 99%

Whisker Formation on SAC305 Soldered Assemblies

Meschter

Snugovsky²,

Bagheri³

et al. 2014

JOM

View full text Add to dashboard Cite

This article describes the results of a whisker formation study on SAC305 assemblies, evaluating the effects of lead-frame materials and cleanliness in different environments: low-stress simulated power cycling (50-85°C thermal cycling), thermal shock (-55°C to 85°C), and high temperature/high humidity (85°C/85% RH). Cleaned and contaminated small outline transistors, large leaded quad flat packs (QFP), plastic leaded chip carrier packages, and solder balls with and without rare earth elements (REE) were soldered to custom designed test boards with Sn3Ag0.5Cu (SAC305) solder. After assembly, all the boards were cleaned, and half of them were recontaminated (1.56 lg/cm 2 Cl À ). Whisker length, diameter, and density were measured. Detailed metallurgical analysis on components before assembly and on solder joints before and after testing was performed. It was found that whiskers grow from solder joint fillets, where the thickness is less than 25 lm, unless REE was present. The influence of lead-frame and solder ball material, microstructure, cleanliness, and environment on whisker characteristics is discussed. This article provides detailed metallurgical observations and select whisker length data obtained during this multiyear testing program.

show abstract

“…5 The heterogeneity of the joint is then connected with the internal stresses because of the difference in the thermal expansion of individual components and the different temperature gradients in the joint during solidification. A consequence of these effects may be lower joint lifetime, as well as undesired effects such as the tombstone effect, 6,7 void formation, 8,9 nonspreading effect, 10,11 flux spattering, 12,13 dewetting, 14 whisker growth, 15,16 etc.…”

Section: Introductionmentioning

confidence: 99%

Study of Undercooling and Recalescence During Solidification of Sn62.5Pb36.5Ag1 and Sn96.5Ag3Cu0.5 Solders in Real Electronic Joints

Rudajevová

Dusek

2014

Journal of Elec Materi

View full text Add to dashboard Cite

Undercooling and recalescence were studied using the differential scanning calorimetry (DSC) method on real electronic systems. Two solder pastes, Sn 62.5 Pb 36.5 Ag 1 and Sn 96.5 Ag 3 Cu 0.5 , were used for preparation of electronic joints. Various combinations of these solders and soldering pads with different surface finishes such as Cu, Cu-Ni-Au, Cu-Sn, and Cu-Sn 99 Cu 1 were used. During melting of both pastes, the Sn and Sn 99 Cu 1 surface finishes immediately dissolved in the solder and the Cu surface coating was exposed to the melt. Therefore, practically the same undercooling was found for the Cu, Cu-Sn, and Cu-Sn 99 Cu 1 coatings. The lowest undercooling was found for the Cu-Ni-Au surface finish for both solder pastes. If two separated electronic joints were made on the sample, two separate peaks were found in the DSC signal during solidification. In the sample with only one joint, only one exothermic peak was found. These findings were observed for all paste/surface finish combinations. These data were analyzed, showing that this effect is a consequence of undercooling and recalescence: Latent heat released during solidification of the joint increases the surrounding temperature and influences all the processes taking place.

show abstract

Effects of reflow atmosphere and flux on Sn whisker growth of Sn–Ag–Cu solders

Cited by 20 publications

References 6 publications

Board Reflow Processes and their Effect on Tin Whisker Growth

Board Reflow Processes and their Effect on Tin Whisker Growth

Whisker Formation on SAC305 Soldered Assemblies

Study of Undercooling and Recalescence During Solidification of Sn62.5Pb36.5Ag1 and Sn96.5Ag3Cu0.5 Solders in Real Electronic Joints

Contact Info

Product

Resources

About