FORMATION OF METALLIC PROJECTION TO METALLIC LEAD

摘要

PURPOSE:To obtain high junction strength and high reliability by simultaneous thermal compression bonding between many metallic projections and metallic leads by suitably selecting the relation between properties and positional dimensions of the materials for the metallic leads and the metallic projections. CONSTITUTION:The metallic lead 30 is composed of a material with less plastic deformation at the time of pressing and heating than the metallic projection 31 transcribed thereto. The width of the lead 30 is smaller in the width B on the side in contact with the metallic projection 31 than in the width A on the side for pressing and heating 32, while the width C of the projection 31 is larger than the width A. This constitution causes the metallic projection to be sufficiently plastically deformed by means of the metallic leads by pressing and heating at the time of joining to Al electrodes of semiconductor elements, and thus to thermally compression-bond the material for the metallic projection to a fresh Al materal, while an oxide film on the Al electrode of the element is removed according to the plastic deformation. Thereby, the junction of high adhesion strength and reliability can be obtained.