The rationalization of cyanate ester die attach adhesives for hermetic packages

• Main Author: Tirol, D.J. Rean D.
• Format: text
• Published: Animo Repository 2009
• Subjects: Adhesives—Testing; Cyanates; Packaging; Engineering Physics; Physical Sciences and Mathematics; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/13345
• Institution: De La Salle University

Two cyanate ester adhesives from different manufacturers were compared in terms of rheology, cure kinetics, and manufacturability. This was done inline with possible source and risk diversification, as well as, for continuous improvement of the current adhesive die attach process. Both materials were subjected to differential scanning calorimetry (DSC), thermogravimetry (TGA), and rheology evaluations. Die attach quality and reliability data, such as stud pull, voiding, bond line thickness, and die tilting were also gathered. Results show that adhesive B changed less in viscosity and thixotropic index after 10 hours. DSC shows an extra peak attributed to a polymer additive included to minimize resin bleed. Less voiding, resin bleed, and degree of tailing were observed for the new adhesive. TGA results show same behavior of both materials in the soak and cure temperatures of the curing profile. Bond line thickness and die tilt are comparable. Stud pull strength is lower for the adhesive B but still within specs. Electrical results show no significant difference between both adhesives. The adhesive B shows promise as an adhesive for the adhesive attach process. However, stud pull strength still has to be improved. Changes in the new material's viscosity can serve as targets for Adhesive A's improvement. High volume evaluation and qualification is recommended when convenient.