Microstructural evolution of joint interface between eutectic 80Au-20Sn solder and UBM

The soldering behaviour of the eutectic Au-Sn alloy on two kinds of under bump metallurgy was studied in relation to time and temperature. For a Ni substrate, two types of the intermetallic compounds were observed at the joint: (Au,Ni)(3)Sn-2 and (Au,Ni)(3)Sn. As the soldering temperature increased, the shape of the (Au,Ni)(3)Sn-2 grains generally changed from a long, thin rod-type to a short, thick type. The degree of buildup of the interfacial intermetallic compounds was similar up to 32 min, even if the soldering was conducted at three different temperatures between 300 degrees C and 400 degrees C. In addition, the reaction of the eutectic Au-Sn solder with the sputtered under bump metallurgy (Al/ Ni(V)/Au) was studied at 300 degrees C. By 20 s of soldering, the protective Au layer was dissolved away and the Ni(V) layer started to dissolve into the solder. Thus, some of the Au reacted with the At underlayer to form the Au8Al3 phase, which was accompanied by volume expansion at the joint. The (Au,Ni)(3)Sn-2 layer was then lifted up, and several interlocked (Au,Ni)(3)Sn-2 grains were broken and separated at weak points along the joint interface. In this way, the joint interface was separated from the Si chip, and a resultant failure occurred in the device.
Publisher
JAPAN INST METALS
Issue Date
2005-11
Language
ENG
Keywords

SN; SYSTEM; NI; CU

Citation

MATERIALS TRANSACTIONS, v.46, no.11, pp.2400 - 2405

ISSN
1345-9678
DOI
10.2320/matertrans.46.2400
URI
http://hdl.handle.net/10203/4603
Appears in Collection
MS-Journal Papers(저널논문)
  • Hit : 520
  • Download : 3
  • Cited 0 times in thomson ci
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡClick to seewebofscience_button
⊙ Cited 10 items in WoSClick to see citing articles inrecords_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0