Evaluation Method for Snap Cure Behavior of Non-conductive Paste for Flip Chip Bonding

Min, Kyung-Eun; Lee, Jun-Sik; Lee, So-Jeong; Yi, Sung; Kim, Jun-Ki

doi:2015.33.5.41

J Weld Join > Volume 33(5); 2015 > Article

Research Paper

Journal of Welding and Joining 2015;33(5):41-46.
DOI: https://doi.org/10.5781/JWJ.2015.33.5.41 Published online October 30, 2015.

Evaluation Method for Snap Cure Behavior of Non-conductive Paste for Flip Chip Bonding

Kyung-Eun Min^*, Jun-Sik Lee^**, So-Jeong Lee^**, Sung Yi^*, Jun-Ki Kim^**,***

Correspondence: Jun-Ki Kim,
Email: jkim@kitech.re.kr

Abstract

The snap cure NCP(non-conducive paste) adhesive material is essentially required for the high productivity flip chip bonding process. In this study, the accessibility of DEA(dielectric analysis) method for the evaluation of snap cure behavior was investigated with comparison to the isothermal DSC(differential scanning calorimetry) method. NCP adhesive was mainly formulated with epoxy resin and imidazole curing agent. Even though there were some noise in the dielectric loss factor curve measured by DEA, the cure start and completion points could be specified clearly through the data processing of cumulation and deviation method. Degree of cure by DEA method which was measured from the variation of the dielectric loss factor of adhesive material was corresponded to about 80% of the degree of cure by DSC method which was measured from the heat of curing reaction. Because the adhesive joint cured to the degree of 80% in the view point of chemical reaction reveals the sufficient mechanical strength, DEA method is expected to be used effectively in the estimation of the high speed curing behavior of snap cure type NCP adhesive material for flip chip bonding.

Key Words: Flip chip bonding, Flip chip adhesive, NCP(non-conductive paste), Curing rate, DEA (dielectric analysis), Isothermal DSC(differential scanning calorimetry)