Skip to main navigation Skip to search Skip to main content

Surface diffusion controlled reaction in small size microbumps

  • Yingxia Liu*
  • , Xiuyu Shi
  • , Haoxiang Ren
  • , Jian Cai
  • , Xiuchen Zhao
  • , Chengwen Tan
  • , K.N. Tu
  • *Corresponding author for this work

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

Abstract

We made head-shaped Cu-Sn solder joints with diameters about 10 μm, 20 μm, and 50 μm and reflowed the samples at 240 °C, 260 °C, and 280 °C for 60 s to 600 s. In the 10 μm bumps, there is only one Cu6Sn5 grain after reflow, thus the classic model of scallop-type grain growth of Cu6Sn5 does not apply. Also, the grain growth in the small size bumps has the faster growth rate. We proposed a surface diffusion-controlled model to explain the new kinetics. According to our model, the diffusion activation energy is calculated to be QS = 0.18 ± 0.02 eV/atom and diffusion frequency factor to be DS0 = 5.65 × 10−3 cm2/s.
Original languageEnglish
Article number129036
JournalMaterials Letters
Volume284
Issue numberPart 1
Online published17 Nov 2020
DOIs
Publication statusPublished - 1 Feb 2021
Externally publishedYes

Research Keywords

  • 3D IC
  • Grain boundaries
  • Interfaces
  • Intermetallic alloys and compounds
  • Lead-free solder
  • Surface diffusion kinetics

Fingerprint

Dive into the research topics of 'Surface diffusion controlled reaction in small size microbumps'. Together they form a unique fingerprint.

Cite this