RF module using MCM-L and BGA technology for 5 GHz WLAN application

This paper presents the design concept and experimental results about small size radio frequency (RF) module for 5 GHz wireless local area network (WLAN). Functions of the RF module include from base band input/output to antenna switch. The size is 20 mm/spl times/15 mm/spl times/3 mm and that is minimum size in modules with same functions as far as the authors get to know. For the purpose of small size and low cost, generally known technologies are used. They are multi chip module on laminated-base dielectric substrate (MCM-L) technology, interconnection of each layer using build-up technology, flip chip technology and ball grid array (BGA) technology. Parts and ICs are on both sides of the RF module's substrate and are vertically connected in the substrate. In order to ensure electrical performance at 5 GHz frequency band in the high-density package, transmission line characteristics in the substrate and BGA characteristic are simulated by 3 dimensional (3D) electromagnetic (EM) software. The fabricated RF module is evaluated using the test set up for 5 GHz WLAN application and the result is shown.