Microstructural variation and high-speed impact responses of Sn–3.0Ag–0.5Cu/ENEPIG solder joints with ultra-thin Ni–P deposit

Ho, Cheng-Ying; Duh, Jenq‐Gong; Lin, Chih‐Wei; Lin, Chun‐Jen; Wu, Yuntian; Hong, Huei-Cheng; Wang, Te-Hui

doi:10.1007/s10853-012-7070-2

Cited by 51 publications

(3 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As Li et al reported that the growth kinetics IMC layer was found to be a diffusion-controlled process, which followed a parabolic relationship in the thickness increase [21]. The growth of ternary IMCs was more complicated [22,23]. The observation that Ni addition could induce a larger amount of bump shape (Cu 1−x Ni x ) 6 Sn 5 during the reflow process deserves more attention in further research.…”

Section: Imc Growth For Complex Componentsmentioning

confidence: 93%

Effect of the reflow process on IMC growth for different devices and complex components

Cui¹,

Tian²,

Zhao³

et al. 2022

Smart Mater. Struct.

View full text Add to dashboard Cite

Intermetallic compound (IMC), as an inevitable part between pad and solder, has a severe effect on the strength and reliability of microelectronic interconnection. Here, an investigation was carried out on IMC growth for different devices and complex components. The device-level experiments were conducted with five factors: peak temperature, time duration above solder liquidus temperature, the thickness of solder paste, surface finish types, and package types including BGA and QFP. Meanwhile, four complex components with the same reflow profile were conducted and compared for component-level experiments. A scanning electron microscopy was used to measure the thickness and determine the spatial distribution of the elements through the intermetallic compound. The multivariate analysis of the formation and growth of IMC during reflow soldering was studied based on Nernst-Shchukarev's equation and the results of the experiments. The difference in IMC thickness between BGA and QFP with different factors was discussed and compared separately. The results showed that the peak temperature and time above liquidus played a vital role in the IMC growth and the solder paste thickness and different pad metallization could not be ignored. SEM pictures of the solder and statistical results were revealed that the surface finish type has a marked impact on the formation of the IMC. For PCB with numbers of components, the IMC thickness and uniformity of solder joints at corner and center positions showed some regularity differences. Meanwhile, the bump shape (Cu1-xNix)6Sn5 IMC was observed for small size BGA with ENIG during the reflow process. The results have a significant meaning to optimize its reflow process parameters for complex components, to improve the interconnection reliability in engineering.

show abstract

Section: Imc Growth For Complex Componentsmentioning

confidence: 93%

Effect of the reflow process on IMC growth for different devices and complex components

Cui¹,

Tian²,

Zhao³

et al. 2022

Smart Mater. Struct.

View full text Add to dashboard Cite

show abstract

“…The formation of Ni 3 Sn 4 intermetallic layer is characteristic for the interface between the Sn-based solder and nickel [9], and its growth rate is slower. Therefore, nickel can serve as an excellent reaction barrier that restricts the excessive dissolution of Cu into the solder joints [10,11]. The structure of the solder pad (such as its roughness) also influences the IMC, though not primarily in its growth rate, but rather in the IMC ratio between various intermetallic phases, such as Ag 3 Sn, Cu 3 Sn, and Cu 6 Sn 5 phases [12], where their presence is both inevitable and necessary.…”

Section: Materials Effect On Imc Growthmentioning

confidence: 99%

Influence of Flux and Related Factors on Intermetallic Layer Growth within SAC305 Solder Joints

et al. 2021

View full text Add to dashboard Cite

Flux contained in solder paste significantly affects the process of solder joint creation during reflow soldering, including the creation of an intermetallic layer (IML). This work investigates the dependence of intermetallic layer thickness on ROL0/ROL1 flux classification, glossy or matt solder mask, and OSP/HASL/ENIG soldering pad surface finish. Two original SAC305 solder pastes differing only in the used flux were chosen for the experiment. The influence of multiple reflows was also observed. The intermetallic layer thicknesses were obtained by the image analysis of micro-section images. The flux type proved to have a significant impact on the intermetallic layer thickness. The solder paste with ROL1 caused an increase in IML thickness by up to 40% in comparison to an identical paste with ROL0 flux. Furthermore, doubling the roughness of the solder mask has increased the resulting IML thickness by 37% at HASL surface finish and by an average of 22%.

show abstract

“…The surface finish was responsible for improved joint reliability. It is germane that surface finish could prevent oxidizing, contamination (Sona and Prabhu, 2014) and act as a diffusion barrier to prevent rapid reaction between the solder and Cu substrate (Rohan et al , 2002; Ho et al , 2013; Pun et al , 2014; Siti Rabiatul Aisha et al , 2015). From the foregoing, it is crucial to seek a reliable surface finish for the Cu substrate applications.…”

Section: Introductionmentioning

confidence: 99%

The formation of intermetallic layer structure of SAC405/Cu and SAC405/ENImAg solder joint interfaces

Anuar

Osman

2020

SSMT

View full text Add to dashboard Cite

Purpose The surface finish is an essential step in printed circuit boards design because it provides a solderable surface for electronic components. The purpose of this study to investigate the effects of different surface finishes during the soldering and ageing process. Design/methodology/approach The solder joints of Sn-4.0Ag-0.5Cu/Cu and Sn-4.0Ag-0.5Cu/electroless nickel/immersion silver (ENImAg) were investigated in terms of intermetallic (IMC) thickness, morphology and shear strength. The microstructure and compositions of solder joints are observed, and analyzed by using scanning electron microscopy (SEM-EDX) and optical microscope (OM). Findings Compounds of Cu6Sn5 and (Cu, Ni)6Sn5 IMC were formed in SAC405/Cu and SAC405/ENImAg, respectively, as-reflowed. When the sample was exposed to ageing, new layers of Cu3Sn and (Ni, Cu)3Sn5 were observed at the interface. Analogous growth in the thickness of the IMC layer and increased grains size commensurate with ageing time. The results equally revealed an increase in shear strength of SAC405/ENImAg because of the thin layer of IMC and surface finish used compared to SAC405/Cu. Hence, a ductile fracture was observed at the bulk solder. Overall, the ENImAg surface finish showed excellent performance of solder joints than that of bare Cu. Originality/value The novel surface finish (ENImAg) has been developed and optimized. This alternative lead-free surface finish solved the challenges in electroless nickel/immersion gold and reduced cost without affecting the performance.

show abstract

Microstructural variation and high-speed impact responses of Sn–3.0Ag–0.5Cu/ENEPIG solder joints with ultra-thin Ni–P deposit

Cited by 51 publications

References 33 publications

Effect of the reflow process on IMC growth for different devices and complex components

Effect of the reflow process on IMC growth for different devices and complex components

Influence of Flux and Related Factors on Intermetallic Layer Growth within SAC305 Solder Joints

The formation of intermetallic layer structure of SAC405/Cu and SAC405/ENImAg solder joint interfaces

Contact Info

Product

Resources

About