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Electronics and Telecommunications Research Institute (한국전자통신연구원)
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Interconnection Technology Based on InSn Solder for Flexible Display Applications

  • Choi, Kwang-Seong (IT Convergence Technology Research Laboratory, ETRI) ;
  • Lee, Haksun (IT Convergence Technology Research Laboratory, ETRI) ;
  • Bae, Hyun-Cheol (IT Convergence Technology Research Laboratory, ETRI) ;
  • Eom, Yong-Sung (IT Convergence Technology Research Laboratory, ETRI) ;
  • Lee, Jin Ho (IT Convergence Technology Research Laboratory, ETRI)
  • Received : 2014.02.08
  • Accepted : 2014.11.28
  • Published : 2015.04.01
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Abstract

A novel interconnection technology based on a 52InSn solder was developed for flexible display applications. The display industry is currently trying to develop a flexible display, and one of the crucial technologies for the implementation of a flexible display is to reduce the bonding process temperature to less than $150^{\circ}C$. InSn solder interconnection technology is proposed herein to reduce the electrical contact resistance and concurrently achieve a process temperature of less than $150^{\circ}C$. A solder bump maker (SBM) and fluxing underfill were developed for these purposes. SBM is a novel bumping material, and it is a mixture of a resin system and InSn solder powder. A maskless screen printing process was also developed using an SBM to reduce the cost of the bumping process. Fluxing underfill plays the role of a flux and an underfill concurrently to simplify the bonding process compared to a conventional flip-chip bonding using a capillary underfill material. Using an SBM and fluxing underfill, a $20{\mu}m$ pitch InSn solder SoP array on a glass substrate was successfully formed using a maskless screen printing process, and two glass substrates were bonded at $130^{\circ}C$.

Keywords

References

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