Partially captured oriented interconnections for BGA packages and a method of forming the interconnections
US6913948B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2003 |
| Grant date | Jul 5, 2005 |
| Priority date | — |
| Expiry date | Nov 20, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/099
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A Ball Grid Array package having an increased fatigue life and improved conductive pad adhesion strength, as well as providing sufficient wiring space within the package, is disclosed. In particular, solder joints having a combination of mask-defined and pad-defined solder joint profiles are formed using a mask having non-circular elongated openings. The non-circular elongated openings of the mask have a major axis and a minor axis, such that the dimension of the openings along the major axis is greater than the diameter of the conductive pads, and the dimension of the openings along the minor axis is less than the diameter of the conductive pads. In addition, the major axis of the openings within the mask are selectively oriented in the direction of highest stress for each solder joint within the package, while providing ample wiring space therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.