| 摘要 |
Copper pillar tin bump on semiconductor chip comprises a copper layer composed on chip and a tin layer entirely wrapping whole outer surface of said copper layer. A method for forming of the copper pillar tin bump on semiconductor chip comprises: composing the first copper layer on said chip; applying photoresist to said first copper layer, exposing and developing a part of said photoresist, composing the copper pillar layer at the developed part of photoresist, composing the upper tin layer, removing said photoresist, removing said the first copper layer except disposing place of copper pillar layer, composing side tin layer. The minute pattern makes it possible to form a high density packaging by reducing a pitch of copper pillar tin bump. Signal delay can be reduced by low electric resistance, and underfill can be easily soaked. |
