Characterization of DAF tape for embedded micro wafer level packaging

The requirements of new packaging technologies for smaller, thinner and lighter electronics products have resulted in electronics industry moving towards wafer level packaging. Some of the main advantages of wafer level packaging are suitability for very fine pitch interconnection, low assembly cost and smaller form factor. This is because the package formed through wafer level technology has the same size as the die itself. Wafer level packaging is in demand especially for portable products such as mobile phone and digital camera. With wafers thinned to 100µm, conventional die attach process may not be suitable as the control of bleed out of the die attached paste becomes critical. New generation of die attach material such as the Dicing Die attach film (DDAF) is introduced to control the paste bleed at the die edge as well as to have a consistent bondline thickness. This paper presents the results of DDAF tape lamination on 100µm thin wafer, DDAF tape dicing process characterization and materials characterization in terms of die shear test of 2 DDAF tapes after die attach process and after subjecting to Moisture Sensitivity test Level 3. A three-factor D.O.E (bonding pressure, bonding temperature and bonding time) adopted to understand the dominant contributing factors on DDAF tape bonding process and to understand the effects of bonding parameters on the DDAF bondline thickness and DDAF voids (Table 1). The 3 selected bond forces range from 0.5kg to 2.5kg. Reliability of the DDAF assembly will also be studied and reported in this work.