Title :
A pillar-shaped via structure in a Cu-polyimide multilayer substrate
Author :
Iwasaki, Noboru ; Yamaguchi, Satoru
Author_Institution :
NTT Appl. Electron. Lab., Tokyo, Japan
Abstract :
The authors describe a novel pillar-shaped via structure in a Cu-polyimide multilayer substrate and its fabrication process. The process forms a fine rectangular via conductor by pattern electroplating, using a thick positive photoresist. A flat polyimide dielectric layer is formed by the photolithographic process using a photosensitive polyimide precursor. The resulting pillar-shaped via conductor is 30-μm square and 25-μm thick. The area occupied by this via conductor is 25% smaller than that of a conventional via not filled with copper conductor, the interconnection density is twice as high, and the thermal resistance is 50% less. The structure is suitable for high-speed signal transmission in a Cu-polyimide multilayer substrate
Keywords :
VLSI; electroplating; packaging; photoresists; 25 micron; Cu; high-speed signal transmission; interconnection density; multilayer substrate; pattern electroplating; photolithographic process; pillar-shaped via structure; polyimide dielectric layer; rectangular via conductor; thick positive photoresist; Conductive films; Conductors; Copper; Dielectric substrates; Fabrication; Nonhomogeneous media; Packaging; Polyimides; Resists; Signal processing;
Conference_Titel :
Electronic Manufacturing Technology Symposium, 1989, Proceedings. Japan IEMT Symposium, Sixth IEEE/CHMT International
Conference_Location :
Nara
DOI :
10.1109/IEMTS.1989.76122
