Study of QFN Pre-tape Material Characteristics & Impacts to Assembly Performance

QFN leadframe is laminated with adhesive tape on the exposed pads side to prevent resin bleed during encapsulation. The material characteristics of three major adhesive types: silicone-based, acrylic and thermoplastic were studied in this project. This paper discusses the differences of the three tapes in terms of material properties and correlation to their assembly performance. The impact of laminated tape to assembly process is of interest as the primary goal of this study is to identify the most suitable material that guarantees desirable process yield at semiconductor backend assembly process (from die attached process to molding), product quality and at the same time without introducing extra cost in cleaning the adhesive residue after tape removal.