Interconnections for flip-chip using lead-free solders and having reaction barrier layers
US7923849B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 2008 |
| Grant date | Apr 12, 2011 |
| Priority date | — |
| Expiry date | Apr 30, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/30107
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An interconnection structure suitable for flip-chip attachment of microelectronic device chips to packages, comprising a two, three or four layer ball-limiting composition including an adhesion/reaction barrier layer, and having a solder wettable layer reactive with components of a tin-containing lead free solder, so that the solderable layer can be totally consumed during soldering, but a barrier layer remains after being placed in contact with the lead free solder during soldering. One or more lead-free solder balls is selectively situated on the solder wetting layer, the lead-free solder balls comprising tin as a predominant component and one or more alloying components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.