Interfacial stress analysis and fracture of a bi-material strip with a heterogeneous underfill

Ji Eun Park, Iwona Jasiuk, Aleksander Zubelewicz

Research output: Contribution to journalArticlepeer-review


Flip chip assemblies used in electronic packaging consist of three main components (layers): chip, underfill, and substrate. In this paper, the flip chip assembly is represented as a bi-material strip consisting of the chip and underfill. Our analysis is focused on delamination along the chip-underfill interface due to thermal loading. The underfill is modeled as a composite material made of a polymer matrix and silica particles. Interfacial stresses are studied for several particle configurations: cases of one, two, or three particles near the interface and 30 different random particle arrangements. Interfacial fracture is investigated by evaluating the J integral and stress intensity factors. Statistics of random particle arrangements in the underfill are also discussed. The interfacial stress and fracture analyses give the same trends.

Original languageEnglish (US)
Pages (from-to)400-413
Number of pages14
JournalJournal of Electronic Packaging, Transactions of the ASME
Issue number3
StatePublished - Sep 2003
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Mechanics of Materials
  • Computer Science Applications
  • Electrical and Electronic Engineering


Dive into the research topics of 'Interfacial stress analysis and fracture of a bi-material strip with a heterogeneous underfill'. Together they form a unique fingerprint.

Cite this