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Author Jang, Guh Yaw ♦ Duh, Jenq Gong
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2005
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences
Subject Keyword Flip chip ♦ Sn-Ag solder ♦ Sn-Pb solder ♦ diffusion ♦ intermetallic compound (IMC) ♦ under-bump metallization (UBM) ♦ Optical and Electronic Materials ♦ Characterization and Evaluation of Materials ♦ Electronics and Microelectronics, Instrumentation ♦ Solid State Physics and Spectroscopy
Abstract The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints was investigated with an assembly of a solder/Ni/Cu/Ti/Si$_{3}$N$_{4}$/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni$_{1−x}$,Cu$_{x}$)$_{3}$Sn$_{4}$ intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles, only the (Ni$_{1−x}$,Cu$_{x}$)$_{3}$Sn$_{4}$ IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu$_{1−y}$,Ni$_{y}$)$_{6}$Sn$_{5}$ IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content in the solder near the solder/IMC interface played an important role in the formation of the (Cu$_{1−y}$,Ni$_{y}$)$_{6}$Sn$_{5}$ IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed. The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer (EPMA). During reflow, the atomic flux of Cu was on the order of 10$^{16}$−10$^{17}$ atoms/cm$^{2}$sec in both the eutectic Sn-Ag and Sn-Pb systems.
ISSN 03615235
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-01-01
Publisher Place New York
e-ISSN 1543186X
Journal Journal of Electronic Materials
Volume Number 34
Issue Number 1
Page Count 12
Starting Page 68
Ending Page 79


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Source: SpringerLink