Method for controlling the formation of intermetallic compounds in solder joints
US6602777B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2002 |
| Grant date | Aug 5, 2003 |
| Priority date | — |
| Expiry date | Mar 20, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12722
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method for controlling the formation of the intermetallic compounds in solder joints, The types of the intermetallic compounds between the SnAgCu solders and the Ni-bearing substrate can be controlled by adjusting the copper concentration in the SnAgCu solders. If the SnAgCu solder has a copper concentration higher than or equivalent to 0.6 wt. %, the soldering intermetallic compound includes a continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is lower than or equivalent to 0.4 wt. %, the soldering intermetallic compound includes a continuous (Ni1−yCuy)3Sn4 layer and a non-continuous (Cu1−xNix)6Sn5 layer. If the copper concentration of the SnAgCu solders is between 0.4 wt. % to 0.6 wt. %, the soldering intermetallic compound includes the continuous (Cu1−xNix)6Sn5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.