Innovations in thermoplastic die attach adhesives for microelectronic packaging

This paper reviews the traditional use of thermoset (epoxy) polymer adhesives and highlights some of the limitations for current microelectronic applications. The development of thermoplastic materials offers many advantages in material options in terms of form and processing. The past two or three years has seen a rapid uptake of these new thermoplastic adhesive materials for attaching large area silicon to a wide range of substrate and package materials. Furthermore, new innovative concepts in die attach, ranging from dry adhesive preform, ribbon and extruded rod processes have been developed in both the USA and Far East, and this paper outlines the techniques used for some of these process options. An outline of some equipment developments to use these new adhesive technologies especially for die attach is given and summary data on “end user” case histories is also presented. The paper concludes with a prediction for the future in that even more novel thermoplastic adhesive materials will be developed, offering a range of both isotropic and anisotropic form options