Embedding of Thinned Chips in Plastic Substrates

Abstract

In standard large volume electronics productions like RFID and smart cards, very small chips are being used and connected by means of flip chip. With increasing functionality and subsequently also die size, the reliability of the flip chip interconnection will decrease especially due to bending of the flexible substrates used in these large volume productions. One possible solution to increase the reliability is to embed the chip inside the substrate. This paper will describe the process flow of a newly developed technology to embed a thinned chip inside a plastic substrate, using UV-curable encapsulants and laser via drilling. This technology also has the potential to make small pitch interconnections from chip to substrate.