Microstructural evolution in Sn/Pb solder and Pb/Ag thick film conductor metallization

Author

Liu, Kuo-Chuan ; Duh, Jenq-Gong

Author_Institution

Dept. of Mater. Sci. & Eng., Nat. Tsing Hua Univ., Hsinchu, Taiwan

Volume

14

Issue

4

fYear

1991

fDate

12/1/1991 12:00:00 AM

Firstpage

703

Lastpage

707

Abstract

Intermetallic compound formation between thick-film mixed bonded conductor and Sn/Pb solder is investigated. Microstructural evolution of the interfacial morphology, and elemental and phase distribution are probed with the aid of electron microscopy and X-ray diffraction. A decrease in adhesion strength occurs when the sample is aged at 130°C for long periods for time. Microstructural analysis reveals the formation of intermetallic compounds Pd₃Sn, Pd₂Sn, Pd₃Sn₂, PdSn, Pd₃Pb, Ag₅Sn, and Ag₃Sn. A possible mechanism of adhesion loss for the conductor is described. In the initial stage, the fracture interface is located where the Pd₃Pb exists, which is near the solder. However, the fracture takes place within the solder after aging. It is argued that volume change of the conductor film resulting from the intermetallic formation and incoherency between the compounds due to grain growth are major factors in the degradation of the peel strength

Keywords

X-ray chemical analysis; X-ray diffraction examination of materials; adhesion; chemical interdiffusion; electron microscope examination of materials; fracture toughness; hybrid integrated circuits; integrated circuit technology; lead alloys; metallisation; palladium alloys; silver alloys; soldering; thick films; tin alloys; 130 degC; Ag₃Sn; Ag₅Sn; Pd₂Sn; Pd₃Pb; Pd₃Sn; Pd₃Sn₂; PdSn; Sn-Pb solder; SnPb-PdAg; X-ray diffraction; adhesion strength; ageing; electron microscopy; elemental distribution; fracture interface; grain growth; hybrid microelectronics; interfacial morphology; intermetallic formation; microstructural evolution; peel strength degradation; phase distribution; thick film conductor metallization; thick-film mixed bonded conductor; volume change; Adhesives; Aging; Bonding; Conductive films; Conductors; Electrons; Intermetallic; Morphology; Thick films; Tin;

fLanguage

English

Journal_Title

Components, Hybrids, and Manufacturing Technology, IEEE Transactions on

Publisher

ieee

ISSN

0148-6411

Type

jour

DOI

10.1109/33.105120

Filename

105120