Process for producing a solder preform having high-melting metal particles dispersed therein
US8790472B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2005 |
| Grant date | Jul 29, 2014 |
| Priority date | — |
| Expiry date | Oct 27, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1216
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
[Problems] A conventional process for producing a solder preform in which a predetermined amount of high-melting metal particles are directly put into molten solder and stirred, requires a long time for dispersing the high-melting metal particles by stirring. Therefore, in the conventional method for producing a solder preform, dissolution of the high-melting metal particles into the molten solder occurred during stirring, and their particle diameters became small. If a semiconductor chip and a substrate are soldered with a solder preform containing metal particles having such decreased diameters, the space between portions being soldered becomes narrow, and a sufficient bonding strength is not obtained.[Means for Solving the Problems] In the present invention, a premixed master alloy having a higher proportion of the high-melting metal particles in solder is first prepared, then the premixed master alloy is put into molten solder to disperse the high-melting metal particles. As a result, the high-melting metal particles can be uniformly dispersed in solder in a short length of time. Accordingly, a solder preform which is obtained by the process for producing a solder preform accor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.