Low temperature melting and mid temperature melting lead-free solder paste with mixed solder alloy powders
US11267080B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2019 |
| Grant date | Mar 8, 2022 |
| Priority date | — |
| Expiry date | Mar 2, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/0272
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.