The presetn study evaluates a new curing method, the varibble Frequency Microwave technique, for processing high reliability adhesive encapsulants. THis process was used to cure three different high quality underfills wiht resultant properties that include low stress, no filler sedimentation , high glass transition temperature and good adhesion. For comparison, the same adhesives were also cured in a convection oven. Three different cure profiles were utilized to investigate their effects on the adhesive properties. These properties were analyzed with the following techniques: T sup g measurements were determined using Differential Scannign Calorimetry, adhesion measurements were derived through a standardized push-off test, stress was evaluated thrugh radiusof curvature measurements, and adhesive sedimentation was studied with Energy Dispersive spectroscopy. Infrared imaging was also used to evaluate the selective heating of the VFM cure. The results suggest that the VFM process is more rapid as ocmpared to the convection cure, i.e, 3.5 to 5 minutes as opposed ot 30 to 120 minutes. Furthermore, the VFM process resulted in a lower stress cure with equivalent mechanical properties of the polymer encapsulants.
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