Open AccessCuring Kinetics and Chemorheological Behavior of No‐flow Underfill for Sn/In/Bi Solder in Flexible Packaging Applications
Author(s) -
Eom YongSung,
Son JiHye,
Bae HyunCheol,
Choi KwangSeong,
Lee JinHo
Publication year - 2016
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.16.0116.0047
Subject(s) - materials science , curing (chemistry) , wetting , soldering , differential scanning calorimetry , composite material , rheology , epoxy , oxide , flip chip , isothermal process , rosin , kinetics , scanning electron microscope , adhesive , thermodynamics , chemical engineering , metallurgy , layer (electronics) , resin acid , engineering , physics , quantum mechanics
A chemorheological analysis of a no‐flow underfill was conducted using curing kinetics through isothermal and dynamic differential scanning calorimetry, viscosity measurement, and solder (Sn/27In/54Bi, melting temperature of 86 °C) wetting observations. The analysis used an epoxy system with an anhydride curing agent and carboxyl fluxing capability to remove oxide on the surface of a metal filler. A curing kinetic of the no‐flow underfill with a processing temperature of 130 °C was successfully completed using phenomenological models such as autocatalytic and n th‐order models. Temperature‐dependent kinetic parameters were identified within a temperature range of 125 °C to 135 °C. The phenomenon of solder wetting was visually observed using an optical microscope, and the conversion and viscosity at the moment of solder wetting were quantitatively investigated. It is expected that the curing kinetics and rheological property of a no‐flow underfill can be adopted in arbitrary processing applications.