High capacity SDRAM memory module with stacked printed circuit boards
US6545895B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2002 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Apr 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K1/144
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a family of memory modules. In one embodiment a memory module with granularity, upgradability, and a capacity of two gigabytes uses 256 MB SDRAM or DDR SDRAM memory devices in CSPs in a volume of just 4.54 inches by 2.83 inches by 0.39 inch. Each module includes an impedance-controlled substrate having contact pads, memory devices, and other components, including optional driver line terminators, on its surfaces. The inclusion of spaced, multiple area array interconnections allows memory devices to be symmetrically mounted on each side of each of the area array interconnections, thereby reducing the interconnect lengths and facilitating the matching of interconnect lengths. Short area array interconnections, including BGA, PGA, and LGA options or interchangeable alternative connectors provide interconnections between the modules and the rest of the system. Thermal control structures may be included to maintain the memory devices within a reliable range of operating temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.