Method of forming cylindrical bumps on a substrate for integrated circuits
US6390356B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2000 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Oct 23, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3025
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming cylindrical bumps on a substrate for integrated circuits includes the steps of: forming copper circuits on a board of a substrate by means of electroplating; covering said board with a screening material; forming openings in said screening material to align with copper circuits on said board, filling pure copper or high melting point metal into said openings by electroplating to form cylindrical projections; forming a layer of solder alloy on an upper end of each of said cylindrical projections to be even with an upper surface of said screening material, and removing said screening material to leave the cylindrical bumps, whereby the engagement operation between the die and the substrate can be facilitated and the manufacture of the die can be easier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.