Variable ball height on ball grid array packages by solder paste transfer
US9842818B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2016 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Mar 28, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0133
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
BGA packages with a spatially varied ball height, molds and techniques to form such packages. A template or mold with cavities may be pre-fabricated to hold solder paste material applied to the mold, for example with a solder paste printing process. The depth and/or diameter of the cavities may be predetermined as a function of spatial position within the mold working surface area. Mold cavity dimensions may be specified corresponding to package position to account for one or more pre-existing or expected spatial variations in the package, such as a package-level warpage measurement. Any number of different ball heights may be provided. The molds may be employed in a standardize process that need not be modified with each change in the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.