Phase identification and interface evolution of ENIG/Cu-core SAC305/ENIG solder joints after the thermal-electrical coupling reliability test

Fleshman, Collin; Song, Rui-Wen; Tsai, Shih-Jen; Duh, Jenq‐Gong

doi:10.1016/j.matlet.2020.128104

Cited by 6 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Solder joints play an important role not only in mechanical connection but also in electrical connection in electronic packaging. Therefore, solder joint reliability is an important research content of modern electronic packaging technology [3][4][5]. In recent years, the surface finish of printed circuit boards (PCBs) has attracted more and more attention because of its protective effect on exposed copper circuits and for providing a good soldering surface, which affects the reliability of electronic packaging solder joints [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Effect of Ni(P) Layer Thickness on Interface Reaction and Reliability of Ultrathin ENEPIG Surface Finish

Chi

Pan

et al. 2021

Materials

View full text Add to dashboard Cite

Electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) is a common surface finish in electronic packaging, while the Ni(P) layer increases the impedance of solder joints and leads to signal quality degradation in high-frequency circuits. Reducing the thickness of the Ni(P) layer can balance the high impedance and weldability. In this paper, the interfacial reaction process between ultrathin ENEPIG substrates with different Ni layer thicknesses (0.112 and 0.185 μm) and Sn–3.0Ag–0.5Cu (SAC305) solder during reflow and aging was studied. The bonding ability and reliability of solder joints with different surface finishes were evaluated based on solder ball shear test, drop test and temperature cycle test (TCT), and the failure mechanism was analyzed from the perspective of intermetallic compound (IMC) interface growth. The results showed that the Ni–Sn–P layer generated by ultrathin ENEPIG can inhibit the growth of brittle IMC so that the solder joints maintain high shear strength. Ultrathin ENEPIG with a Ni layer thickness of 0.185 μm had no failure cracks under thermal cycling and drop impact, which can meet actual reliability standards. Therefore, ultrathin ENEPIG has broad prospects and important significance in the field of high-frequency chip substrate design and manufacturing.

show abstract