Composite solder alloy preform
US8348139B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2010 |
| Grant date | Jan 8, 2013 |
| Priority date | — |
| Expiry date | Mar 9, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12722
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Various embodiments of the invention provide laminate composite preform foils for high-temperature Pb-free soldering applications. The laminate composite preform foil is composed of a high-melting, ductile metal or alloy core layer and a low-melting solder coating layer at either side of the core layer. During soldering, the core metal, liquid solder layer, and substrate metals react and consume the low-melting solder phase to form high-melting intermetallic compound phases (IMCs). The resultant solder joint is composed of a ductile core layer sandwiched by the IMCs layers at substrate sides. The joint has a much higher remelt temperature than the original melting temperature of the initial solder alloy coating, allowing subsequent mounting of packaged devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.