Retardation of the Cu5Zn8 Phase Fracture and Improvement of Shear Strength of the Sn-9 wt pct Zn/Cu Interface by Inserting an Electroless Palladium Layer

Lee, Po-Hsun; Lin, Chern‐Sheng; Chen, Chih‐Ming

doi:10.1007/s11661-012-1377-0

Cited by 5 publications

(3 citation statements)

References 13 publications

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“…To further investigate the effect of minor Ni addition on the mechanical property of solder joints, additional shear test was performed. The Cu substrates of tested samples (reacted at 200°C for 240 h) were firmly fixed on a stationary stage of a testing machine (Type A2, Cometech, Taiwan) [11]. The speed of the shear tool was fixed at 800 lm/s and the shear height was 60 lm.…”

Section: Resultsmentioning

confidence: 99%

“…The LF35 solder also displayed better bending performance as compared with the SnAgCu solder, indicating that LF35 was a good candidate employed in the solder joints for high-temperature and vibration applications [8]. In addition to mechanical properties, microstructural examination of the joint interface is also crucial for basic characterization of solder joints [9][10][11]. This study aimed to investigate the interfacial reactions between LF35 solder and common Cu substrate.…”

Section: Introductionmentioning

confidence: 99%

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Interfacial reactions between Cu and SnAgCu solder doped with minor Ni

Cheng

Huang

Lee

et al. 2015

Journal of Alloys and Compounds

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Interfacial reactions between Cu and SnAgCu solder doped with minor Ni

Cheng

Huang

Lee

et al. 2015

Journal of Alloys and Compounds

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“…Related investigations have been extensively performed to provide helpful information for reliability evaluation of solder joints. [1][2][3][4][5][6][7] The Cu conductor and metallization on PCB and Si chip can be fabricated using various methods, among which electroplating is widely used due to economic consideration. Electroplating is an electrochemical process involving complicated interaction between various additives used in the Cu plating bath, such as suppressor, accelerator, and so on.…”

mentioning

confidence: 99%

Effects of Electroplating Additives on the Interfacial Reactions between Sn and Cu Electroplated Layers

Lee

et al. 2014

J. Electrochem. Soc.

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Three combinations of additives based on polyethylene glycol (PEG), Cl − ions, bis(3-sulfopropyl)disulfide (SPS), and Alcian Blue (ABPV) were used to fabricate the Cu plated layer. The additive combination was found to play an important role in the microstructural evolution of the Cu plated layer. The PC (PEG + Cl − ) case produced the Cu plated layer with grains of a smaller size and random morphology, while the PCS (PEG + Cl − + SPS) and PCSA (PEG + Cl − + SPS + ABPV) cases produced the Cu plated layers with grains of a larger size and faceted morphology. Experimental results based on metallurgical examination and trace element analysis indicated that the interfacial reactions between Sn and Cu plated layers strongly depended upon the additive combination used in the Cu plating solution, and the dependence was reasonably correlated with the grain morphology of the Cu plated layer combined with the incorporation of organic impurities.Cu is commonly used for conductors and metallizations in printed circuit board (PCB) and Si integrated-circuit (IC) chip due to its superior electrical conductivity and good wettability with solder materials. Sn is extensively used in microelectronic solders due to its suitable melting point, efficient mechanical property, and low cost. So, the Sn/Cu joints massively exist in the microelectronic products. To form a Sn/Cu joint, reflow is conducted during which the Sn melts and wets the Cu substrate. The intermetallic compounds (IMC) are usually formed as a result of the interfacial reaction between Sn and Cu. Related investigations have been extensively performed to provide helpful information for reliability evaluation of solder joints. [1][2][3][4][5][6][7] The Cu conductor and metallization on PCB and Si chip can be fabricated using various methods, among which electroplating is widely used due to economic consideration. Electroplating is an electrochemical process involving complicated interaction between various additives used in the Cu plating bath, such as suppressor, accelerator, and so on. These additives interacted with each other on the Cu surface and inevitably were partially incorporated into the Cu plated layer during electroplating. The incorporation of organic impurities in the Cu plated layers during plating was found to have significant effects on the interfacial reactions between Sn-based solder and Cu plated substrate. [8][9][10][11][12][13] The S residue of about 17 ppm was detected in the Cu plated layer when a high level (3 × 10 −5 M) of accelerator, SPS (bissodium sulfopropyldisulfide, C 6 H 12 O 6 S 4 Na 2 ), was added in the Cu plating bath. 8 Large amounts of void were formed at the Cu/Cu 3 Sn interface along with the solder/Cu interfacial reaction during 150 • C aging, which was attributed to the reduction of free energy barrier for void formation due to interfacial segregation of S. Voids were continuously formed during aging and merged into several gaps within the Cu-Sn IMCs, forming an alternating layered structure composed of gaps and IMCs at the Sn-3...

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