Large Area Processing (LAP) has been developed to address the industry's requirements for very fine lines and spaces (under 1 mil), fine via geometries, and very low manufacturing costs when compared to traditional wafer-based thin film interconnect technologies. At MicroModule Systems, LAP substrates are built on 400/spl times/400 mm panels using various metal, organic, and inorganic substrate starting materials. A photo-sensitive dielectric material from Dow (Photo-BCB), with copper traces and gold pad metallization. Each panel yields approximately a 10X improvement in available substrates per panel over 150 mm round wafers, resulting in a significant reduction in the cost to manufacture. The paper will trace the implementation of LAP substrate technology at MMS. We will review different substrate starting materials and process equipment challenges, and the impact of LAP implementation on a single-chip BGA application.

The processing conditions for photosensitive BCB (Cyclotene** 4024-40 and Cyclotene** 4026-46) were defined for a thin film Cu/Photo-BCB MCM-D structure. Fabrication of four layer MCM-Ds, designed by Sandia National Laboratories, was demonstrated. The modules were electrically tested, solder bumped, flip chip assembled and put through a reliability test program