Correlation Between Whisker Initiation and Compressive Stress in Electrodeposited Tin–Copper Coating on Copper Leadframes

Kato, Takahiko; Akahoshi, Haruo; Nakamura, Masato; Terasaki, Takeshi; Iwasaki, Takaya; Hashimoto, Takashi; Nishimura, A.

doi:10.1109/tepm.2010.2045384

Cited by 19 publications

(21 citation statements)

References 13 publications

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“…Hence, Sn-Cu finishes are often used in combination with other mitigation practices such as heat treatment [16] or base material selection [45][46][47][48][49][50][51][52]. The whisker mitigation effectiveness of the heat-treated Sn-Cu finish was shown earlier (Figs.…”

Section: Tin-copper (Sn-cu) Finishmentioning

confidence: 99%

“…It also introduces metallurgical techniques studied by Kato et al [45][46][47][48][49][50][51][52] in order to illuminate the mechanisms of the formation and suppression of whisker growth from the Sn-Cu coating.…”

Section: Dependence Of Whisker Propensity Of Matte Tin-copper Finish mentioning

confidence: 99%

“…In studies by Kato et al [45][46][47][48][49][50][51][52] of the effects of long-term storage at room temperature, whiskers did not grow from the Sn-Cu coating on the CUCR lead frame, whereas long whiskers, up to about 200 μm long, grew from that on the CUFE lead frame.…”

Section: Dependence Of Whisker Propensity Of Matte Tin-copper Finish mentioning

confidence: 99%

“…The coatings were characterized by EBSP measurement [47,[50][51][52] for vertical cross sections of the longitudinal lead-frame direction for Sn-Cu/CUFE and Sn-Cu/CUCR samples and on the planar-sliced surface of the coating at about the center of the lead-frame width for an Sn-Cu/CUFE sample. This was done using a TexSEM Laboratories orientation imaging microscopy system (MSC-2200) operating at an acceleration voltage of 20 kV.…”

Section: Crystalline Orientations and Grain-size Distributions At Cromentioning

confidence: 99%

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Properties and Whisker Formation Behavior of Tin‐Based Alloy Finishes

Kato

Handwerker

Bath

2016

Mitigating Tin Whisker Risks

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Section: Tin-copper (Sn-cu) Finishmentioning

confidence: 99%

Section: Dependence Of Whisker Propensity Of Matte Tin-copper Finish mentioning

confidence: 99%

Section: Dependence Of Whisker Propensity Of Matte Tin-copper Finish mentioning

confidence: 99%

Section: Crystalline Orientations and Grain-size Distributions At Cromentioning

confidence: 99%

See 2 more Smart Citations

Properties and Whisker Formation Behavior of Tin‐Based Alloy Finishes

Kato

Handwerker

Bath

2016

Mitigating Tin Whisker Risks

Self Cite

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“…1,2) It was believed that the movement of dislocations plays a primary role in whisker formation (dislocation mechanism), 3) but now a stress gradient inside the Sn layer and Sn-atom transport are thought to be the important factors for whiskers. 4,5) Various attempts for mitigation against the whisker formation, e.g., alloying to be Sn-Ag and Sn-Bi and thermal processing such as a reflow treatment, have been made. However, the mechanism of whisker-growth has not been well understood and the complete prevention from whisker formation has not yet been established to date.…”

Section: Introductionmentioning

confidence: 99%

Effects of Post-Plating Reflow on Changes in Crystal Grain Size of Sn-2 mass%Bi Alloy Plating with Thermal Cycling Treatment

et al. 2010

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Changes in the grain size of tin (Sn) crystals associated with a thermal cycling treatment were investigated for layers of Sn-2 mass%Bi electroplated on Fe-42Ni substrates in order to clarify the effects of post-plating reflow. Morphology of plated surface was observed by scanning electron microscopy (SEM) and scanning ion microscopy (SIM), and the Sn-grains were observed by electron beam back scattered diffraction (EBSD). Microstructures were also analyzed with a transmission electron microscope (TEM) in order to investigate the process of whisker formation. It was found that the Sn grains in Sn-Bi specimen are smaller than those in pure Sn specimen at the initial state of as-plating, after the reflow treatment and after the thermal cycling treatment of 1500 cycles. On the Sn-Bi specimen without a reflow treatment, short whiskers had grown after 100 cycles of thermal cycling treatment, but on those with the reflow treatment, relatively-long whiskers were formed after 500 cycles. The grain sizes increase temporarily after the reflow treatment and also after the very early stage of thermal cycling treatment, but gradually decreased with the thermal cycling treatment. The phenomenon is explained by the ''deformation and recrystallization'' effects of the thermal cycling treatment.

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