Large format fabrication-a practical approach to low cost MCM-D

The IBM Microelectronics Division at East Fishkill has recently demonstrated the fabrication of thin films for MCM-D on large area panels, 300 mm×300 mm in size. Fabrication of the thin films was accomplished on IBM´s 300 mm development line using immersion development of photosensitive polyimide for via formation and electrolytic plating to define wiring and terminal metal levels. One plane pair of thin films was constructed on Corning glass 7059 panels for 35 μm lines on 85 μm pitch. In addition, two metal-dielectric levels with 13 μm lines on 25 μm pitch have also been demonstrated. The 25 μm pitch represents the most aggressive groundrule practised in electronic packaging today. The successful production of electrically good substrates at a high yield from a 300 mm panel provides a gateway to significant cost reductions of future MCM-D products. This paper discusses the processes and equipment used to fabricate two different test vehicles, as well as some of the cost and yield considerations associated with large area panel processing for MCM-D packages